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Sample records for present-day mexican-mestizos revealed

  1. KIR gene diversity in Mexican mestizos of San Luis Potosí.

    PubMed

    Alvarado-Hernández, Diana Lorena; Hernández-Ramírez, Daniel; Noyola, Daniel Ernesto; García-Sepúlveda, Christian Alberto

    2011-09-01

    Natural killer (NK) cell function is regulated by different types of membrane-bound receptors of which killer-cell immunoglobulin-like receptors (KIRs) are the most complex and diverse. KIRs are encoded by 17 different genes located within the leukocyte receptor complex (19q13.4). The frequency with which KIR gene features are present in different human populations differs. Here, we present our results on the KIR gene diversity observed in a large group of mestizos from the central Mexican city of San Luis Potosí. In total, 53 different KIR genotypes were observed, 47 with previously described gene profiles and six harboring novel KIR gene combinations. Group A homozygous haplotypes were seen in 102 individuals (34%), while group B homozygous haplotypes were present in 45 (15%). Heterozygous combinations of groups A and B haplotypes were seen in 153 individuals (51%). Haplotype frequency estimations based on a true content of 600 chromosomes showed a relatively balanced proportion of group A (59.5%) and group B (40.5%) haplotypes in our study population. A homozygous combination of the cA01|tA01 haplotype was present in 33% of the population with other frequent combinations being cA01|tA01, cB03|tB01 in 14.7% and cA01|tA01, cB02|tA01 in 12%. The dendrogram derived from activating KIR gene phylogenetic analysis revealed five clearly distinct clades corresponding to African, East Asian, Arab/Caucasoid, Mexican mestizo/Amerindian and South Asian populations. Our results illustrate the genetic contribution that Caucasoid and Amerindian populations have made toward present-day Mexicans and suggest an important Southeast Asian genetic contribution to native Amerindian populations.

  2. Distinctive autoantibody profile in Mexican Mestizo systemic sclerosis patients.

    PubMed

    Rodriguez-Reyna, Tatiana S; Hinojosa-Azaola, Andrea; Martinez-Reyes, Cynthia; Nuñez-Alvarez, Carlos A; Torrico-Lavayen, Rocío; García-Hernández, José Luis; Cabiedes-Contreras, Javier

    2011-11-01

    Systemic sclerosis (SSc) shows variable clinical expression among different ethnic groups. Herein, we describe the clinical features, prevalence of organ involvement, and autoantibody profile in Mexican Mestizo SSc patients and we compare them with patients from other ethnic groups.We included 139 SSc patients. They underwent clinical evaluation and were tested for antinuclear antibodies (ANA), anticentromere antibodies (ACA), anti-topoisomerase I, anti-RNA polymerase III, anti-U1 RNP, anti-U3 RNP, anti-U11/U12 RNP, anti-Th/To, anti-PM-Scl, anti-Ku, antinucleosome, anti-double-stranded DNA (dsDNA), anti-Sm, anti-SSA, and anti-SSB antibodies. Female predominance (93.5%) was noted; 56.8% of patients had limited cutaneous SSc; 91% had peripheral vascular involvement; 70% had joint involvement; 27% had musculoskeletal damage; 66% had gastrointestinal involvement; 41% had interstitial lung disease; 32% had pulmonary arterial hypertension (PAH); 11% had cardiac involvement; and in 1.4% renal involvement was observed. Our patients showed lower frequency of renal crisis and higher frequency of PAH than patients from other ethnic groups; also they showed higher frequency of ACA than Japanese and African American patients, higher frequency of anti-topoisomerase I than Caucasian and African American patients, higher frequency of anti-PM-Scl and anti-Ku and lower frequency of anti-RNA Pol III than the other ethnic groups. High frequencies of antinucleosome (41%) and anti-dsDNA (63%) were identified. SSc-specific autoantibody frequencies are different in our patients and in those from other ethnic groups; associations of autoantibodies with clinical manifestations are confirmed in our patients. Ethnicity and the interaction of gene and environmental factors may influence the clinical picture and autoantibody profile in SSc patients.

  3. Adenoma of the Nonpigmented Ciliary Body and Iris Epithelium in Mexican Mestizo Patients

    PubMed Central

    Serna-Ojeda, Juan Carlos; Ariza-Camacho, Enrique; Collado-Solórzano, Alberto; Flores-Sánchez, Blanca C.; Rodríguez-Reyes, Abelardo A.; Fulda-Graue, Emiliano

    2015-01-01

    The adenoma of the nonpigmented ciliary epithelium is a benign rare tumor, which may present with different clinical characteristics and requires resection along with histopathologic analysis and the identification of specific immunohistochemical markers for an accurate diagnosis. Here, we report a case series of 4 patients in a Mexican mestizo population with this diagnosis, their clinical features, the ultrasound imaging characteristics and the histopathological and immunohistochemical findings. PMID:27171918

  4. Mexican mestizo population sub-structure: effects on genetic and forensic statistical parameters.

    PubMed

    Noris, Gino; Santana, Carla; Meraz-Ríos, Marco Antonio; de Lourdes Munoz, María; Majluf-Cruz, Abraham; Magaña, Jonathan J; Granados, Julio; Quezada, Rosa; Revilla, María Cristina; Martínez-Salas, Sergio; Xihuitl, Salvador; Martínez de la Escalera, Gonzalo; Díaz-Badillo, Alvaro; Calderon-Aranda, Emma S; Gómez, Rocío

    2012-12-01

    Since Mexican mestizos are an admixed population, it is necessary to determine the effects that the substructure of the population has on genetic and forensic parameters. With this aim, a study was performed with 15 STR loci (CODIS plus D2S1338 and D19S433) on 1,640 unrelated Mexican mestizos. We determine allele and genotypic frequencies observing departure from Hardy-Weinberg expectation (12 out of 15 loci, with an excess of homozygotes, Fis > 0), as well as pairs of loci in an apparent linkage disequilibrium (13 of 92 loci). We conducted a test for genetic population stratification, the results show that the Mexican mestizo population is substructured into three subgroups, which are in HW and linkage equilibrium. The combination of the 15 loci in the whole population has high forensic efficiency with the capacity to genetically discriminate one individual in one quintillion (1/10(18)). Our data potentially validates the use of these 15 STR loci to establish forensic identity and parentage testing for legal purposes, and offers a powerful tool for genetic variation analysis. However, given that the population is stratified, we highly recommend applying a correction with the inbreeding coefficient in calculations of paternity and forensic studies to avoid erroneous assumptions.

  5. The rs3857059 variant of the SNCA gene is associated with Parkinson's disease in Mexican Mestizos.

    PubMed

    García, S; Chavira-Hernández, G; Gallegos-Arreola, M P; Dávila-Maldonado, L; García Martínez, F; Montes Almanza, L A; Palma-Flores, C; Mondragón-Terán, P; Alcaraz Estrada, S L; López-Hernández, L B

    2016-06-01

    Among the candidate genes for Parkinson's disease (PD), SNCA has replicated association in different populations. Besides other known mutations in the SNCA gene, the rs3857059 variant has also been linked to various neurodegenerative disorders. Therefore, the aim of the present study was to search for association of this variant and sporadic PD in Mexican Mestizo patients. A case-control study was performed including 241 individuals, 106 patients, and 135 healthy controls. Genotyping was performed using real-time PCR. The rs3857059 variant demonstrated an association with PD in Mexican Mestizos (OR = 2.40, CI, 1.1 to 5.1, p = 0.02) under the recessive model. In addition, a gender effect was found for the GG genotype in females (OR = 1.31, CI, 1.01 to 1.7, p = 0.037). This is the first study to confirm an association of the rs3857059 variant with PD and also to show a gender effect. Our data contribute to the elucidation of the link between rs3857059 and susceptibility to PD observed in the Mexican Mestizo population. PMID:27332068

  6. The rs3857059 variant of the SNCA gene is associated with Parkinson's disease in Mexican Mestizos.

    PubMed

    García, S; Chavira-Hernández, G; Gallegos-Arreola, M P; Dávila-Maldonado, L; García Martínez, F; Montes Almanza, L A; Palma-Flores, C; Mondragón-Terán, P; Alcaraz Estrada, S L; López-Hernández, L B

    2016-06-01

    Among the candidate genes for Parkinson's disease (PD), SNCA has replicated association in different populations. Besides other known mutations in the SNCA gene, the rs3857059 variant has also been linked to various neurodegenerative disorders. Therefore, the aim of the present study was to search for association of this variant and sporadic PD in Mexican Mestizo patients. A case-control study was performed including 241 individuals, 106 patients, and 135 healthy controls. Genotyping was performed using real-time PCR. The rs3857059 variant demonstrated an association with PD in Mexican Mestizos (OR = 2.40, CI, 1.1 to 5.1, p = 0.02) under the recessive model. In addition, a gender effect was found for the GG genotype in females (OR = 1.31, CI, 1.01 to 1.7, p = 0.037). This is the first study to confirm an association of the rs3857059 variant with PD and also to show a gender effect. Our data contribute to the elucidation of the link between rs3857059 and susceptibility to PD observed in the Mexican Mestizo population.

  7. Mitogenomes from The 1000 Genome Project Reveal New Near Eastern Features in Present-Day Tuscans

    PubMed Central

    Pardo-Seco, Jacobo; Amigo, Jorge; Martinón-Torres, Federico

    2015-01-01

    Background Genetic analyses have recently been carried out on present-day Tuscans (Central Italy) in order to investigate their presumable recent Near East ancestry in connection with the long-standing debate on the origins of the Etruscan civilization. We retrieved mitogenomes and genome-wide SNP data from 110 Tuscans analyzed within the context of The 1000 Genome Project. For phylogeographic and evolutionary analysis we made use of a large worldwide database of entire mitogenomes (>26,000) and partial control region sequences (>180,000). Results Different analyses reveal the presence of typical Near East haplotypes in Tuscans representing isolated members of various mtDNA phylogenetic branches. As a whole, the Near East component in Tuscan mitogenomes can be estimated at about 8%; a proportion that is comparable to previous estimates but significantly lower than admixture estimates obtained from autosomal SNP data (21%). Phylogeographic and evolutionary inter-population comparisons indicate that the main signal of Near Eastern Tuscan mitogenomes comes from Iran. Conclusions Mitogenomes of recent Near East origin in present-day Tuscans do not show local or regional variation. This points to a demographic scenario that is compatible with a recent arrival of Near Easterners to this region in Italy with no founder events or bottlenecks. PMID:25786119

  8. Polymorphisms of APLN-APLNR system are associated with essential hypertension in Mexican-Mestizo individuals.

    PubMed

    Esteban-Martínez, Rosa Lilia; Pérez-Razo, Juan Carlos; Vargas-Alarcón, Gilberto; Martínez-Rodríguez, Nancy; Cano-Martínez, Luis Javier; López-Hernández, Luz Berenice; Rojano-Mejía, David; Canto, Patricia; Coral-Vazquez, Ramón Mauricio

    2016-08-01

    The aim of this study was to evaluate if polymorphisms of APLN and APLNR genes may play a role as susceptibility markers for hypertension in a group of Mexican-Mestizo patients. A case-control study was carried out including normotensive and hypertensive individuals. For these, two polymorphisms of APLN (rs3761581 and rs56204867) and two of APLNR () genes were genotyped by 5' exonuclease TaqMan assay in 400 normotensive individuals and 383 patients. The results showed that, under an additive model adjusted by BMI, HDL, triglycerides, glucose and family history of essential hypertension, the rs7119375 and rs10501367 polymorphisms of APLNR gene were associated significantly with a decreased risk of essential hypertension (P=0.039 and P=0.029, respectively). Besides, the haplotypes analysis of these polymorphisms showed that H1 haplotype was associated with an increased risk of essential hypertension (P=0.026), while the H2 haplotype was associated with a decreased risk (P=0.032). Contrary, the rs3761581 and rs56204867 polymorphisms of APLN gene were not associated with essential hypertension (P=0.1707 and P=0.0769, respectively). The data suggest that APLNR rs7119375 and rs10501367 are associated with a decreased risk of essential hypertension in our Mexican-Mestizo studied group, but further studies are warranted. PMID:27450650

  9. [Monoclonal gammopathy of undetermined significance (MGUS) in Mexican mestizos: one institution's experience].

    PubMed

    Ruiz-Delgado, Guillermo J; Gómez Rangel, J David

    2004-01-01

    Monoclonal gammopathy of undetermined significance (MGUS) is defined as presence of serum monoclonal protein at a concentration of 3 g per deciliter or less, no monoclonal protein or only moderate amounts of monoclonal light chains in urine, absence of lytic bone lesions, anemia, hypercalemia, and renal insufficiency related with monoclonal protein, and with a proportion of plasma cells in bone marrow of 10% or less. In Caucasian population, MGUS affects about 3% of individuals > 70 years of age, whereas in Mexican mestizos this figure is substantially lower (0.7%); on the other hand, MGUS represents in Mexico only 2.4% of all monoclonal gammopathies. In a total of 9081 individuals studied prospectively at the Centro de Hematología y Medicina Interna de Puebla throughout a 20-year period, 11 patients with MGUS were identified. Median age was 70 years (range 43-83 years). Patients have been followed in periods ranging from 6 to 3270 days (median, 308 days). Two patients evolved into overt multiple myeloma at 308 and 1687 days after diagnosis of MGUS. Overall median survival (SV) of the group has not been reached, whereas 3270 days overall SV is 91%. After discussing underreporting, biasing, and other confounding factors, it would seem that MGUS, like other monoclonal gammopathies, is less frequent in Mexican mestizos than in Caucasians. Routine screening studies to identify the condition should result in increased numbers of patients.

  10. Analysis of genomic diversity in Mexican Mestizo populations to develop genomic medicine in Mexico.

    PubMed

    Silva-Zolezzi, Irma; Hidalgo-Miranda, Alfredo; Estrada-Gil, Jesus; Fernandez-Lopez, Juan Carlos; Uribe-Figueroa, Laura; Contreras, Alejandra; Balam-Ortiz, Eros; del Bosque-Plata, Laura; Velazquez-Fernandez, David; Lara, Cesar; Goya, Rodrigo; Hernandez-Lemus, Enrique; Davila, Carlos; Barrientos, Eduardo; March, Santiago; Jimenez-Sanchez, Gerardo

    2009-05-26

    Mexico is developing the basis for genomic medicine to improve healthcare of its population. The extensive study of genetic diversity and linkage disequilibrium structure of different populations has made it possible to develop tagging and imputation strategies to comprehensively analyze common genetic variation in association studies of complex diseases. We assessed the benefit of a Mexican haplotype map to improve identification of genes related to common diseases in the Mexican population. We evaluated genetic diversity, linkage disequilibrium patterns, and extent of haplotype sharing using genomewide data from Mexican Mestizos from regions with different histories of admixture and particular population dynamics. Ancestry was evaluated by including 1 Mexican Amerindian group and data from the HapMap. Our results provide evidence of genetic differences between Mexican subpopulations that should be considered in the design and analysis of association studies of complex diseases. In addition, these results support the notion that a haplotype map of the Mexican Mestizo population can reduce the number of tag SNPs required to characterize common genetic variation in this population. This is one of the first genomewide genotyping efforts of a recently admixed population in Latin America.

  11. Analysis of genomic diversity in Mexican Mestizo populations to develop genomic medicine in Mexico

    PubMed Central

    Silva-Zolezzi, Irma; Hidalgo-Miranda, Alfredo; Estrada-Gil, Jesus; Fernandez-Lopez, Juan Carlos; Uribe-Figueroa, Laura; Contreras, Alejandra; Balam-Ortiz, Eros; del Bosque-Plata, Laura; Velazquez-Fernandez, David; Lara, Cesar; Goya, Rodrigo; Hernandez-Lemus, Enrique; Davila, Carlos; Barrientos, Eduardo; March, Santiago; Jimenez-Sanchez, Gerardo

    2009-01-01

    Mexico is developing the basis for genomic medicine to improve healthcare of its population. The extensive study of genetic diversity and linkage disequilibrium structure of different populations has made it possible to develop tagging and imputation strategies to comprehensively analyze common genetic variation in association studies of complex diseases. We assessed the benefit of a Mexican haplotype map to improve identification of genes related to common diseases in the Mexican population. We evaluated genetic diversity, linkage disequilibrium patterns, and extent of haplotype sharing using genomewide data from Mexican Mestizos from regions with different histories of admixture and particular population dynamics. Ancestry was evaluated by including 1 Mexican Amerindian group and data from the HapMap. Our results provide evidence of genetic differences between Mexican subpopulations that should be considered in the design and analysis of association studies of complex diseases. In addition, these results support the notion that a haplotype map of the Mexican Mestizo population can reduce the number of tag SNPs required to characterize common genetic variation in this population. This is one of the first genomewide genotyping efforts of a recently admixed population in Latin America. PMID:19433783

  12. Polymorphisms of APLN-APLNR system are associated with essential hypertension in Mexican-Mestizo individuals.

    PubMed

    Esteban-Martínez, Rosa Lilia; Pérez-Razo, Juan Carlos; Vargas-Alarcón, Gilberto; Martínez-Rodríguez, Nancy; Cano-Martínez, Luis Javier; López-Hernández, Luz Berenice; Rojano-Mejía, David; Canto, Patricia; Coral-Vazquez, Ramón Mauricio

    2016-08-01

    The aim of this study was to evaluate if polymorphisms of APLN and APLNR genes may play a role as susceptibility markers for hypertension in a group of Mexican-Mestizo patients. A case-control study was carried out including normotensive and hypertensive individuals. For these, two polymorphisms of APLN (rs3761581 and rs56204867) and two of APLNR () genes were genotyped by 5' exonuclease TaqMan assay in 400 normotensive individuals and 383 patients. The results showed that, under an additive model adjusted by BMI, HDL, triglycerides, glucose and family history of essential hypertension, the rs7119375 and rs10501367 polymorphisms of APLNR gene were associated significantly with a decreased risk of essential hypertension (P=0.039 and P=0.029, respectively). Besides, the haplotypes analysis of these polymorphisms showed that H1 haplotype was associated with an increased risk of essential hypertension (P=0.026), while the H2 haplotype was associated with a decreased risk (P=0.032). Contrary, the rs3761581 and rs56204867 polymorphisms of APLN gene were not associated with essential hypertension (P=0.1707 and P=0.0769, respectively). The data suggest that APLNR rs7119375 and rs10501367 are associated with a decreased risk of essential hypertension in our Mexican-Mestizo studied group, but further studies are warranted.

  13. Maternal admixture and population structure in Mexican-Mestizos based on mtDNA haplogroups.

    PubMed

    Martínez-Cortés, Gabriela; Salazar-Flores, Joel; Haro-Guerrero, Javier; Rubi-Castellanos, Rodrigo; Velarde-Félix, Jésus S; Muñoz-Valle, José F; López-Casamichana, Mavil; Carrillo-Tapia, Eduardo; Canseco-Avila, Luis M; Bravi, Claudio M; López-Armenta, Mauro; Rangel-Villalobos, Héctor

    2013-08-01

    The maternal ancestry (mtDNA) has important applications in different research fields, such as evolution, epidemiology, identification, and human population history. This is particularly interesting in Mestizos, which constitute the main population in Mexico (∼93%) resulting from post-Columbian admixture between Spaniards, Amerindians, and African slaves, principally. Consequently, we conducted minisequencing analysis (SNaPshot) of 11 mitochondrial single-nucleotide polymorphisms in 742 Mestizos of 10 populations from different regions in Mexico. The predominant maternal ancestry was Native American (92.9%), including Haplogroups A, B, C, and D (47, 23.7, 15.9, and 6.2%, respectively). Conversely, European and African ancestries were less frequent (5.3 and 1.9%, respectively). The main characteristics of the maternal lineages observed in Mexican-Mestizos comprised the following: 1) contrasting geographic gradient of Haplogroups A and C; 2) increase of European lineages toward the Northwest; 3) low or absent, but homogeneous, African ancestry throughout the Mexican territory; 4) maternal lineages in Mestizos roughly represent the genetic makeup of the surrounding Amerindian groups, particularly toward the Southeast, but not in the North and West; 5) continuity over time of the geographic distribution of Amerindian lineages in Mayas; and 6) low but significant maternal population structure (FST  = 2.8%; P = 0.0000). The average ancestry obtained from uniparental systems (mtDNA and Y-chromosome) in Mexican-Mestizos was correlated with previous ancestry estimates based on autosomal systems (genome-wide single-nucleotide polymorphisms and short tandem repeats). Finally, the comparison of paternal and maternal lineages provided additional information concerning the gender bias admixture, mating patterns, and population structure in Mestizos throughout the Mexican territory.

  14. Ancient DNA reveals matrilineal continuity in present-day Poland over the last two millennia.

    PubMed

    Juras, Anna; Dabert, Miroslawa; Kushniarevich, Alena; Malmström, Helena; Raghavan, Maanasa; Kosicki, Jakub Z; Metspalu, Ene; Willerslev, Eske; Piontek, Janusz

    2014-01-01

    While numerous ancient human DNA datasets from across Europe have been published till date, modern-day Poland in particular, remains uninvestigated. Besides application in the reconstruction of continent-wide human history, data from this region would also contribute towards our understanding of the history of the Slavs, whose origin is hypothesized to be in East or Central Europe. Here, we present the first population-scale ancient human DNA study from the region of modern-day Poland by establishing mitochondrial DNA profiles for 23 samples dated to 200 BC - 500 AD (Roman Iron Age) and for 20 samples dated to 1000-1400 AD (Medieval Age). Our results show that mitochondrial DNA sequences from both periods belong to haplogroups that are characteristic of contemporary West Eurasia. Haplotype sharing analysis indicates that majority of the ancient haplotypes are widespread in some modern Europeans, including Poles. Notably, the Roman Iron Age samples share more rare haplotypes with Central and Northeast Europeans, whereas the Medieval Age samples share more rare haplotypes with East-Central and South-East Europeans, primarily Slavic populations. Our data demonstrates genetic continuity of certain matrilineages (H5a1 and N1a1a2) in the area of present-day Poland from at least the Roman Iron Age until present. As such, the maternal gene pool of present-day Poles, Czechs and Slovaks, categorized as Western Slavs, is likely to have descended from inhabitants of East-Central Europe during the Roman Iron Age. PMID:25337992

  15. Protective effect of DRB1 locus against type 2 diabetes mellitus in Mexican Mestizos.

    PubMed

    Perez-Luque, Elva; Alaez, Carmen; Malacara, Juan Manuel; Garay, M Eugenia; Fajardo, Martha E; Nava, Laura E; Gorodezky, Clara

    2003-01-01

    The aim of the study was to investigate the participation of human leukocyte antigen (HLA) class II alleles in the expression of type 2 diabetic and in nondiabetic subjects with and without family history of diabetes. The purpose was to evaluate any HLA association and to look for different patterns of insulin resistance and insulin secretion, comparing subjects with a low probability of developing diabetes, as a result of their family history. We recruited 87 healthy subjects without family history of diabetes, 48 healthy subjects with family history, and 47 type 2 diabetic patients. All of them were Mexican Mestizos of central Mexico. Using a standard 75-g oral glucose tolerance test, insulin resistance was determined and insulin secretion was assessed with the HOMA model. DRB1, DQA1 and DQB1 alleles were typed using polymerase chain reaction-sequence-specific oligonucleotide probe (PCR-SSOP) and sequence specific primers (PCR-SSP). Nondiabetic subjects had similar HOMA-IR and DeltaI 30/DeltaG 30 index (HOMA). A significant decreased frequency of DRB1*0403 (p = 0.01; odds ratio [OR] = 0.20) was demonstrated in type 2 diabetic patients, and DRB1*0701 (p = 0.02; OR = 0.17) in nondiabetics with family history of diabetes. These alleles associated with protection against type 2 diabetes, share glutamic acid at position-74 and were previously demonstrated to contribute to protection against type I diabetes.

  16. Present day vertical deformation of Pico and Faial islands revealed by merged INSAR and GPS data

    NASA Astrophysics Data System (ADS)

    Catalao, Joao; Nico, Giovanni; Catita, Cristina

    2010-05-01

    SAR line-of-sight velocity and the GPS horizontal velocity component. Later, the vertical velocity offsets are numerically determined by comparison between GPS (ITRF velocities) and PS (the two ascending and descending sets) measurements. These values are then used to create the vertical deformation map of Faial and Pico islands with considerably better resolution and accuracy than using a single set of observations. The vertical deformation map has identified a large continuous area of subsidence on the west of Faial island, on the flank of Capelinhos eruption cone, with a maximum subsidence range of 10 mm/yr. It has also revealed the subsidence of the summit crater of Pico island (9 mm/yr) and a large area of subsidence on the west of the island, corresponding mostly to creep movement. Key words: SAR Interferometry, GPS-INSAR integration, Volcano, subsidence

  17. Admixture and genetic relationships of Mexican Mestizos regarding Latin American and Caribbean populations based on 13 CODIS-STRs.

    PubMed

    Salazar-Flores, J; Zuñiga-Chiquette, F; Rubi-Castellanos, R; Álvarez-Miranda, J L; Zetina-Hérnandez, A; Martínez-Sevilla, V M; González-Andrade, F; Corach, D; Vullo, C; Álvarez, J C; Lorente, J A; Sánchez-Diz, P; Herrera, R J; Cerda-Flores, R M; Muñoz-Valle, J F; Rangel-Villalobos, H

    2015-02-01

    Short tandem repeats (STRs) of the combined DNA index system (CODIS) are probably the most employed markers for human identification purposes. STR databases generated to interpret DNA profiles are also helpful for anthropological purposes. In this work, we report admixture, population structure, and genetic relationships of Mexican Mestizos with respect to Latin American and Caribbean populations based on 13 CODIS-STRs. In addition, new STR population data were included from Tijuana, Baja California (Northwest, Mexico), which represents an interesting case of elevated genetic flow as a bordering city with the USA. Inter-population analyses included CODIS-STR data from 11 Mexican Mestizo, 12 Latin American and four Caribbean populations, in addition to European, Amerindian, and African genetic pools as ancestral references. We report allele frequencies and statistical parameters of forensic interest (PD, PE, Het, PIC, typical PI), for 15 STRs in Tijuana, Baja California. This Mexican border city was peculiar by the increase of African ancestry, and by presenting three STRs in Hardy-Weinberg disequilibrium, probably explained by recurrent gene flow. The Amerindian ancestry in Central and Southeast of Mexico was the greatest in Latin America (50.9-68.6%), only comparable with the North of Central America and Ecuador (48.8-56.4%), whereas the European ancestry was prevalent in South America (66.7-75%). The African ancestry in Mexico was the smallest (2.2-6.3%) in Latin America (≥ 2.6%), particularly regarding Brazil (21%), Honduras (62%), and the Caribbean (43.2-65.2%). CODIS-STRs allowed detecting significant population structure in Latin America based on greater presence of European, Amerindian, and African ancestries in Central/South America, Mexican Mestizos, and the Caribbean, respectively. PMID:25435058

  18. Admixture and genetic relationships of Mexican Mestizos regarding Latin American and Caribbean populations based on 13 CODIS-STRs.

    PubMed

    Salazar-Flores, J; Zuñiga-Chiquette, F; Rubi-Castellanos, R; Álvarez-Miranda, J L; Zetina-Hérnandez, A; Martínez-Sevilla, V M; González-Andrade, F; Corach, D; Vullo, C; Álvarez, J C; Lorente, J A; Sánchez-Diz, P; Herrera, R J; Cerda-Flores, R M; Muñoz-Valle, J F; Rangel-Villalobos, H

    2015-02-01

    Short tandem repeats (STRs) of the combined DNA index system (CODIS) are probably the most employed markers for human identification purposes. STR databases generated to interpret DNA profiles are also helpful for anthropological purposes. In this work, we report admixture, population structure, and genetic relationships of Mexican Mestizos with respect to Latin American and Caribbean populations based on 13 CODIS-STRs. In addition, new STR population data were included from Tijuana, Baja California (Northwest, Mexico), which represents an interesting case of elevated genetic flow as a bordering city with the USA. Inter-population analyses included CODIS-STR data from 11 Mexican Mestizo, 12 Latin American and four Caribbean populations, in addition to European, Amerindian, and African genetic pools as ancestral references. We report allele frequencies and statistical parameters of forensic interest (PD, PE, Het, PIC, typical PI), for 15 STRs in Tijuana, Baja California. This Mexican border city was peculiar by the increase of African ancestry, and by presenting three STRs in Hardy-Weinberg disequilibrium, probably explained by recurrent gene flow. The Amerindian ancestry in Central and Southeast of Mexico was the greatest in Latin America (50.9-68.6%), only comparable with the North of Central America and Ecuador (48.8-56.4%), whereas the European ancestry was prevalent in South America (66.7-75%). The African ancestry in Mexico was the smallest (2.2-6.3%) in Latin America (≥ 2.6%), particularly regarding Brazil (21%), Honduras (62%), and the Caribbean (43.2-65.2%). CODIS-STRs allowed detecting significant population structure in Latin America based on greater presence of European, Amerindian, and African ancestries in Central/South America, Mexican Mestizos, and the Caribbean, respectively.

  19. Calpain-10 gene polymorphisms and risk of type 2 diabetes mellitus in Mexican mestizos.

    PubMed

    Picos-Cárdenas, V J; Sáinz-González, E; Miliar-García, A; Romero-Zazueta, A; Quintero-Osuna, R; Leal-Ugarte, E; Peralta-Leal, V; Meza-Espinoza, J P

    2015-01-01

    The calpain-10 gene is expressed primarily in tissues important in glucose metabolism; thus, some of its polymorphisms have been associated with type 2 diabetes. In this study, we examined the association between the calpain-10 single-nucleotide polymorphism (SNP)-43, SNP-19, and SNP-63 and type 2 diabetes in Mexican mestizos. We included 211 patients and 152 non-diabetic subjects. Polymerase chain reaction was used to identify alleles. We compared allele, genotype, haplotype, and diplotype frequencies between both groups and used the chi-square test to calculate the risk. The allele frequency of SNP-43 allele 1 was 70% in controls and 72% in patients; the GG, GA, and AA genotype frequencies were 48.7, 42.8, and 8.5% in controls and 51.2, 41.7, and 7.1% in patients, respectively. For SNP- 19, the prevalence of allele 1 (2R) was 32% in controls and 39% in patients. In controls, homozygosity (2R/2R) was 10.5%, heterozygosity was 42.8%, and 3R/3R was 46.7%; in cases, these values were 13.3, 50.7, and 36.0%, respectively. For SNP-63, the frequency of allele 1 was 87% in controls and 83% in patients; genotype frequencies in controls were 75.7% (CC), 23% (CT), and 1.3% (TT), and were 69.7, 27.5, and 2.8%, respectively for the cases. Genotype distributions were consistent with Hardy-Weinberg equilibrium. No significant intergroup differences for allele, genotype, haplotype, or diplotype frequencies were observed. We found no association between these polymorphisms and diabetes. However, our sample size was small, so the role of calpain-10 risk alleles should be further examined. PMID:25867367

  20. Calpain-10 gene polymorphisms and risk of type 2 diabetes mellitus in Mexican mestizos.

    PubMed

    Picos-Cárdenas, V J; Sáinz-González, E; Miliar-García, A; Romero-Zazueta, A; Quintero-Osuna, R; Leal-Ugarte, E; Peralta-Leal, V; Meza-Espinoza, J P

    2015-03-27

    The calpain-10 gene is expressed primarily in tissues important in glucose metabolism; thus, some of its polymorphisms have been associated with type 2 diabetes. In this study, we examined the association between the calpain-10 single-nucleotide polymorphism (SNP)-43, SNP-19, and SNP-63 and type 2 diabetes in Mexican mestizos. We included 211 patients and 152 non-diabetic subjects. Polymerase chain reaction was used to identify alleles. We compared allele, genotype, haplotype, and diplotype frequencies between both groups and used the chi-square test to calculate the risk. The allele frequency of SNP-43 allele 1 was 70% in controls and 72% in patients; the GG, GA, and AA genotype frequencies were 48.7, 42.8, and 8.5% in controls and 51.2, 41.7, and 7.1% in patients, respectively. For SNP- 19, the prevalence of allele 1 (2R) was 32% in controls and 39% in patients. In controls, homozygosity (2R/2R) was 10.5%, heterozygosity was 42.8%, and 3R/3R was 46.7%; in cases, these values were 13.3, 50.7, and 36.0%, respectively. For SNP-63, the frequency of allele 1 was 87% in controls and 83% in patients; genotype frequencies in controls were 75.7% (CC), 23% (CT), and 1.3% (TT), and were 69.7, 27.5, and 2.8%, respectively for the cases. Genotype distributions were consistent with Hardy-Weinberg equilibrium. No significant intergroup differences for allele, genotype, haplotype, or diplotype frequencies were observed. We found no association between these polymorphisms and diabetes. However, our sample size was small, so the role of calpain-10 risk alleles should be further examined.

  1. Bone mineral density in postmenopausal Mexican-Mestizo women with normal body mass index, overweight, or obesity.

    PubMed

    Méndez, Juan Pablo; Rojano-Mejía, David; Pedraza, Javier; Coral-Vázquez, Ramón Mauricio; Soriano, Ruth; García-García, Eduardo; Aguirre-García, María Del Carmen; Coronel, Agustín; Canto, Patricia

    2012-12-30

    OBJECTIVE: Obesity and osteoporosis are two important public health problems that greatly impact mortality and morbidity. Several similarities between these complex diseases have been identified. The aim of this study was to analyze if different body mass indexes (BMIs) are associated with variations in bone mineral density (BMD) among postmenopausal Mexican-Mestizo women with normal weight, overweight, or different degrees of obesity. METHODS: We studied 813 postmenopausal Mexican-Mestizo women. A structured questionnaire for risk factors was applied. Height and weight were used to calculate BMI, whereas BMD in the lumbar spine (LS) and total hip (TH) was measured by dual-energy x-ray absorptiometry. We used ANCOVA to examine the relationship between BMI and BMDs of the LS, TH, and femoral neck (FN), adjusting for confounding factors. RESULTS: Based on World Health Organization criteria, 15.13% of women had normal BMI, 39.11% were overweight, 25.96% had grade 1 obesity, 11.81% had grade 2 obesity, and 7.99% had grade 3 obesity. The higher the BMI, the higher was the BMD at the LS, TH, and FN. The greatest differences in size variations in BMD at these three sites were observed when comparing women with normal BMI versus women with grade 3 obesity. CONCLUSIONS: A higher BMI is associated significantly and positively with a higher BMD at the LS, TH, and FN.

  2. Contribution of Common Genetic Variation to the Risk of Type 2 Diabetes in the Mexican Mestizo Population

    PubMed Central

    Gamboa-Meléndez, Marco Alberto; Huerta-Chagoya, Alicia; Moreno-Macías, Hortensia; Vázquez-Cárdenas, Paola; Ordóñez-Sánchez, María Luisa; Rodríguez-Guillén, Rosario; Riba, Laura; Rodríguez-Torres, Maribel; Guerra-García, María Teresa; Guillén-Pineda, Luz Elizabeth; Choudhry, Shweta; del Bosque-Plata, Laura; Canizales-Quinteros, Samuel; Pérez-Ortiz, Gustavo; Escobedo-Aguirre, Fernando; Parra, Adalberto; Lerman-Garber, Israel; Aguilar-Salinas, Carlos Alberto; Tusié-Luna, María Teresa

    2012-01-01

    Several studies have identified nearly 40 different type 2 diabetes susceptibility loci, mainly in European populations, but few of them have been evaluated in the Mexican population. The aim of this study was to examine the extent to which 24 common genetic variants previously associated with type 2 diabetes are associated in Mexican Mestizos. Twenty-four single nucleotide polymorphisms (SNPs) in or near genes (KCNJ11, PPARG, TCF7L2, SLC30A8, HHEX, CDKN2A/2B, CDKAL1, IGF2BP2, ARHGEF11, JAZF1, CDC123/CAMK1D, FTO, TSPAN8/LGR5, KCNQ1, THADA, ADAMTS9, NOTCH2, NXPH1, RORA, UBQLNL, and RALGPS2) were genotyped in Mexican Mestizos. A case-control association study comprising 1,027 type 2 diabetic individuals and 990 control individuals was conducted. To account for population stratification, a panel of 104 ancestry-informative markers was analyzed. Association to type 2 diabetes was found for rs13266634 (SLC30A8), rs7923837 (HHEX), rs10811661 (CDKN2A/2B), rs4402960 (IGF2BP2), rs12779790 (CDC123/CAMK1D), and rs2237892 (KCNQ1). In addition, rs7754840 (CDKAL1) was associated in the nonobese type 2 diabetic subgroup, and for rs7903146 (TCF7L2), association was observed for early-onset type 2 diabetes. Lack of association for the rest of the variants may have resulted from insufficient power to detect smaller allele effects. PMID:22923468

  3. Genetic variations in toll-like receptor 4 in Mexican-Mestizo patients with intra-abdominal infection and/or pneumonia.

    PubMed

    Rodriguez-Osorio, Carlos A; Lima, Guadalupe; Herrera-Caceres, Jaime O; Villegas-Torres, Beatriz E; Zuñiga, Joaquin; Ponce-de-Leon, Sergio; Llorente, Luis; Sifuentes-Osornio, Jose

    2013-06-01

    Sepsis is a leading cause of death around the world, and 73-83% of all sepsis cases requiring attention in intensive care units are linked to intra-abdominal infection (IAI) or pneumonia. The activation of innate immunity is central to the manifestation of sepsis, and toll-like receptor (TLR) 4 plays an important role in this activation process. The 299G and 399I alleles of TLR4 have been linked with an increased risk of Gram-negative bacteria (GNB) infections and septic shock in some populations. This case-control study evaluated the prevalence of D299G/T399I polymorphisms in Mexican patients with IAI and/or pneumonia and in healthy controls. Genotyping revealed that 1 in 44 patients (2.3%; CI 95%: 0.05-12.0%) and 4 in 126 controls (3.2%; CI 95%: 0.9-7.9%) were heterozygous for both the D299G and T399l polymorphisms (OR: 0.71, CI 95%: 0.01-7.44, p = NS), confirming the co-segregation of these alleles in this population. Furthermore, the patients with a GNB infection and severe sepsis were not carriers of the risk alleles. In summary, this report shows that the frequency of the D299G and T399I polymorphisms in Mexican-Mestizos is lower than anticipated in comparison with other ethnic groups, emphasizing the variable distribution of TLR4 polymorphisms among different populations. Consequently, this study was not able to detect associations between TLR4 polymorphisms and sepsis in this population.

  4. Genetic polymorphisms of interleukin-1 alpha and the vitamin d receptor in mexican mestizo patients with intervertebral disc degeneration.

    PubMed

    Cervin Serrano, Salvador; González Villareal, Dalia; Aguilar-Medina, Maribel; Romero-Navarro, Jose Guillermo; Romero Quintana, Jose Geovanni; Arámbula Meraz, Eliakym; Osuna Ramírez, Ignacio; Picos-Cárdenas, Veronica; Granados, Julio; Estrada-García, Iris; Sánchez-Schmitz, Guzman; Ramos-Payán, Rosalío

    2014-01-01

    Intervertebral disc degeneration (IDD) is the most common diagnosis in patients with back pain, a leading cause of musculoskeletal disability worldwide. Several conditions, such as occupational activities, gender, age, and obesity, have been associated with IDD. However, the development of this disease has strong genetic determinants. In this study, we explore the possible association between rs1800587 (c.-949C>T) of interleukin-1 alpha (IL1A) and rs2228570 (c.2T>V) and rs731236 (c.1056T>C) of vitamin D receptor (VDR) gene polymorphisms and the development of IDD in northwestern Mexican Mestizo population. Gene polymorphisms were analyzed by polymerase chain reaction followed by restriction fragment length polymorphism, in two groups matched by age and gender: patients with symptomatic lumbar IDD (n = 100) and subjects with normal lumbar-spine MRI-scans (n = 100). Distribution of the mutated alleles in patients and controls was 27.0% versus 28.0% (P = 0.455) for T of rs1800587 (IL1A); 53.0% versus 58.0% (P = 0.183) for V of rs2228570 (VDR); and 18.0% versus 21.0% (P = 0.262) for C of rs731236 (VDR). Our results showed no association between the studied polymorphisms and IDD in this population. This is the first report on the contribution of gene polymorphisms on IDD in a Mexican population.

  5. Genetic Polymorphisms of Interleukin-1 Alpha and the Vitamin D Receptor in Mexican Mestizo Patients with Intervertebral Disc Degeneration

    PubMed Central

    Cervin Serrano, Salvador; González Villareal, Dalia; Aguilar-Medina, Maribel; Romero-Navarro, Jose Guillermo; Romero Quintana, Jose Geovanni; Arámbula Meraz, Eliakym; Osuna Ramírez, Ignacio; Picos-Cárdenas, Veronica; Granados, Julio; Estrada-García, Iris; Sánchez-Schmitz, Guzman; Ramos-Payán, Rosalío

    2014-01-01

    Intervertebral disc degeneration (IDD) is the most common diagnosis in patients with back pain, a leading cause of musculoskeletal disability worldwide. Several conditions, such as occupational activities, gender, age, and obesity, have been associated with IDD. However, the development of this disease has strong genetic determinants. In this study, we explore the possible association between rs1800587 (c.-949C>T) of interleukin-1 alpha (IL1A) and rs2228570 (c.2T>V) and rs731236 (c.1056T>C) of vitamin D receptor (VDR) gene polymorphisms and the development of IDD in northwestern Mexican Mestizo population. Gene polymorphisms were analyzed by polymerase chain reaction followed by restriction fragment length polymorphism, in two groups matched by age and gender: patients with symptomatic lumbar IDD (n = 100) and subjects with normal lumbar-spine MRI-scans (n = 100). Distribution of the mutated alleles in patients and controls was 27.0% versus 28.0% (P = 0.455) for T of rs1800587 (IL1A); 53.0% versus 58.0% (P = 0.183) for V of rs2228570 (VDR); and 18.0% versus 21.0% (P = 0.262) for C of rs731236 (VDR). Our results showed no association between the studied polymorphisms and IDD in this population. This is the first report on the contribution of gene polymorphisms on IDD in a Mexican population. PMID:25506053

  6. High resolution human leukocyte antigen (HLA) class I and class II allele typing in Mexican mestizo women with sporadic breast cancer: case-control study

    PubMed Central

    2009-01-01

    Background The development of breast cancer is multifactorial. Hormonal, environmental factors and genetic predisposition, among others, could interact in the presentation of breast carcinoma. Human leukocyte antigen (HLA) alleles play an important role in immunity (cellular immunity) and may be important genetic traits. HLAAllele-specific interaction has not been well established. Recently, several studies had been conducted in order to do so, but the results are controversial and in some instances contradictory. Methods We designed a case-control study to quantify the association of HLA class I and II genes and breast cancer. HLA typing was performed by high resolution sequence-specific oligotyping after DNA amplification (PCR-SSOP) of 100 breast cancer Mexican mestizo patients and 99 matched healthy controls. Results HLA-A frequencies that we were able to observe that there was no difference between both groups from the statistical viewpoint. HLA-B*1501 was found three times more common in the case group (OR, 3.714; p = 0.031). HLA-Cw is not a marker neither for risk, nor protection for the disease, because we did not find significant statistical differences between the two groups. DRB1*1301, which is expressed in seven cases and in only one control, observing an risk increase of up to seven times and DRB1*1602, which behaves similarly in being present solely in the cases (OR, 16.701; 95% CI, 0.947 – 294.670). DQ*0301-allele expression, which is much more common in the control group and could be protective for the presentation of the disease (OR, 0.078; 95% CI, 0.027–0.223, p = 0.00001). Conclusion Our results reveal the role of the MHC genes in the pathophysiology of breast cancer, suggesting that in the development of breast cancer exists a disorder of immune regulation. The triggering factor seems to be restricted to certain ethnic groups and certain geographical regions since the relevant MHC alleles are highly diverse. This is the first study in Mexican

  7. P2X7 and NRAMP1/SLC11 A1 gene polymorphisms in Mexican mestizo patients with pulmonary tuberculosis

    PubMed Central

    Niño-Moreno, P; Portales-Pérez, D; Hernández-Castro, B; Portales-Cervantes, L; Flores-Meraz, V; Baranda, L; Gómez-Gómez, A; Acuña-Alonzo, V; Granados, J; González-Amaro, R

    2007-01-01

    Tuberculosis remains one of the most important infectious diseases worldwide. Several studies have suggested that genetic factors may affect susceptibility to tuberculosis, but the specific genes involved have not yet been fully characterized. NRAMP1/SLC11 A1 and P2X7 genes have been linked to increased risk for tuberculosis in some African and Asiatic populations. To explore the potential role of these genes in the susceptibility to pulmonary tuberculosis in a Mexican mestizo population, we evaluated the association of D543N and 3′-UTR polymorphisms in NRAMP1/SLC11 A1 and − 762 and A1513C polymorphisms in P2X7 genes with the risk for tuberculosis. Polymerase chain reaction (PCR) amplification of genomic DNA followed by restriction fragment length polymorphism analysis, and allelic-specific PCR was employed. We found no significant differences in allelic frequency in NRAMP1/SLC11 A1 gene polymorphisms in 94 patients with tuberculosis compared to 100 healthy contacts. Similarly, no significant association of the P2X7−762 gene polymorphism with tuberculosis was detected. In contrast, the P2X7 A1513C polymorphism was associated significantly with tuberculosis (P= 0·02, odds ratio = 5·28, 95% CI, 0·99–37·69), an association that had not been reported previously. However, when the function of P2X7 was assessed by an l-selectin loss assay, we did not find significant differences in patients compared to healthy contacts or between PPD+ and PPD– control individuals. This study further supports the complex role of P2X7 gene in host regulation of Mycobacterium tuberculosis infection, and demonstrates that different associations of gene polymorphisms and tuberculosis are found in distinct racial populations. PMID:17493019

  8. Genetic Variants in IL6R and ADAM19 are Associated with COPD Severity in a Mexican Mestizo Population.

    PubMed

    Pérez-Rubio, Gloria; Silva-Zolezzi, Irma; Fernández-López, Juan Carlos; Camarena, Ángel; Velázquez-Uncal, Mónica; Morales-Mandujano, Fabiola; Hernández-Zenteno, Rafael De Jesús; Flores-Trujillo, Fernando; Sánchez-Romero, Candelaria; Velázquez-Montero, Alejandra; Espinosa de Los Monteros, Carlos; Sansores, Raúl H; Ramírez-Venegas, Alejandra; Falfán-Valencia, Ramcés

    2016-10-01

    Chronic obstructive pulmonary disease (COPD) is a complex and multifactorial disease with a strong genetic component. Our objective is to identify the genetic variants associated with COPD risk and its severity in Mexican Mestizo population. We evaluated 1285 single-nucleotide polymorphisms (SNPs) of candidate genes in 299 smokers with COPD (COPD-S) and 531 smokers without COPD (SWOC) using an Illumina GoldenGate genotyping microarray. In addition, 251 ancestry informative markers were included. Allele A of rs2545771 in CYP2F2P is associated with a lower risk of COPD (p = 4.02E-10, odds ratio [OR] = 0.104, confidence interval [CI] 95% 0.05-0.18). When the COPD group was stratified by severity according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD; levels III + IV vs. I + II), 3 SNPs (rs4329505 and rs4845626 in interleukin 6 receptor [IL6R] and rs1422794 in a disintegrin and metalloproteinase domain 19 [ADAM19]) were associated with a lower risk of suffering the most severe stages of the disease. rs2819096 in the surfactant protein D (SFTPD) gene was associated with a higher risk of COPD GOLD III + IV (p = 7.79E-03, OR = 1.80, CI 95% 1.16-2.79). Finally, the haplotype in IL6R was associated with a lower risk of suffering from more severe COPD, whereas the haplotype in ADAM19 was associated with a higher risk (p = 7.40E-03, OR = 2.83, CI 95% 1.20-6.86) of suffering from the severe stages of the disease. Our data suggest that there are alleles and haplotypes in the IL6R, ADAM19, and SFTPD genes associated with different severity stages of COPD; in CYP2F2P, rs25455771 is associated with a lower risk of COPD.

  9. JAG1 and COL1A1 polymorphisms and haplotypes in relation to bone mineral density variations in postmenopausal Mexican-Mestizo Women.

    PubMed

    Rojano-Mejía, David; Coral-Vázquez, Ramón M; Espinosa, Leticia Cortes; López-Medina, Guillermo; Aguirre-García, María C; Coronel, Agustín; Canto, Patricia

    2013-04-01

    Osteoporosis is characterized by low bone mineral density (BMD). One of the most important factors that influence BMD is the genetic contribution. The collagen type 1 alpha 1 (COL1A1) and the JAGGED (JAG1) have been investigated in relation to BMD. The aim of this study was to investigate the possible association between two single-nucleotide polymorphisms (SNPs) of COL1A1, their haplotypes, and one SNP of JAG1 with BMD in postmenopausal Mexican-Mestizo women. Seven hundred and fifty unrelated postmenopausal women were included. Risk factors were recorded and BMD was measured in lumbar spine, total hip, and femoral neck by dual-energy X-ray absorptiometry. DNA was obtained from blood leukocytes. Two SNPs in COL1A1 (rs1800012 and rs1107946) and one in JAG1 (rs2273061) were studied. Real-time PCR allelic discrimination was used for genotyping. The differences between the means of the BMDs according to genotype were analyzed with covariance. Deviations from Hardy-Weinberg equilibrium were tested. Pairwise linkage disequilibrium between single nucleotide polymorphisms was calculated by direct correlation r (2), and haplotype analysis of COL1A1 was conducted. Under a dominant model, the rs1800012 polymorphism of the COL1A1 showed an association with BMD of the lumbar spine (P = 0.021). In addition, analysis of the haplotype of COL1A1 showed that the G-G haplotype presented a higher BMD in lumbar spine. We did not find an association between the s1107946 and rs2273061 polymorphisms of the COL1A1 and JAG1, respectively. Our results suggest that the rs1800012 polymorphism of the COL1A1, in addition to one haplotype, were significantly associated with BMD variation in Mexican-Mestizo postmenopausal women.

  10. Analysis of polymorphisms in interleukin-10, interleukin-6, and interleukin-1 receptor antagonist in Mexican-Mestizo women with pre-eclampsia.

    PubMed

    Valencia Villalvazo, Elith Yazmin; Canto-Cetina, Thelma; Romero Arauz, Juan Fernando; Coral-Vázquez, Ramón Mauricio; Canizales-Quinteros, Samuel; Coronel, Agustín; Carlos Falcón, Juan; Hernández Rivera, Jaime; Ibarra, Roberto; Polanco Reyes, Lucila; Canto, Patricia

    2012-11-01

    Due to the fact that studies seeking associations of polymorphisms in regulatory regions of cytokine genes with pre-eclampsia (PE) have not always been consistent in different population analyses, the aim of this study was to investigate the possible association between rs1800896 of interleukin-10 (IL-10), rs1800795 of interleukin-6 (IL-6), and the variable number of tandem repeats (VNTR) in intron 2 of interleukin-1 receptor antagonist (IL-1Ra), as well as gene-gene interactions between these three polymorphisms with the presence of PE in Mexican-Mestizo women and one Amerindian population from México (Maya). A case-control study was performed where 411 pre-eclamptic cases and 613 controls were genotyped. For the rs1800896 of IL-10 and rs1800795 of IL-6, we used real-time polymerase chain reaction (PCR) allelic discrimination and for the VNTR of IL-1Ra, PCR. Allele frequency differences were assessed by Chi-squared test; logistic regression was used to test for associations; a gene-gene interaction was conducted. Genotypic and allelic distribution of the polymorphisms was similar in our population. The estimated of the gene-gene interaction between the polymorphisms did not differ significantly. However, we observed important differences in the distribution of the alleles and genotypes of the three polymorphisms analyzed between Mestiza-Mexicanas and Maya-Mestizo women. In conclusion, we did not find an association between polymorphisms in IL-10, IL-6, and IL-1Ra and PE in Mexican-Mestizo and Maya-Mestizo women. To our knowledge, this is the first time that these three polymorphisms were analyzed together with gene-gene interaction in women with PE.

  11. Analysis of Polymorphisms in Interleukin-10, Interleukin-6, and Interleukin-1 Receptor Antagonist in Mexican-Mestizo Women with Pre-eclampsia

    PubMed Central

    Valencia Villalvazo, Elith Yazmin; Canto-Cetina, Thelma; Romero Arauz, Juan Fernando; Coral-Vázquez, Ramón Mauricio; Canizales-Quinteros, Samuel; Coronel, Agustín; Carlos Falcón, Juan; Hernández Rivera, Jaime; Ibarra, Roberto; Polanco Reyes, Lucila

    2012-01-01

    Due to the fact that studies seeking associations of polymorphisms in regulatory regions of cytokine genes with pre-eclampsia (PE) have not always been consistent in different population analyses, the aim of this study was to investigate the possible association between rs1800896 of interleukin-10 (IL-10), rs1800795 of interleukin-6 (IL-6), and the variable number of tandem repeats (VNTR) in intron 2 of interleukin-1 receptor antagonist (IL-1Ra), as well as gene–gene interactions between these three polymorphisms with the presence of PE in Mexican-Mestizo women and one Amerindian population from México (Maya). A case–control study was performed where 411 pre-eclamptic cases and 613 controls were genotyped. For the rs1800896 of IL-10 and rs1800795 of IL-6, we used real-time polymerase chain reaction (PCR) allelic discrimination and for the VNTR of IL-1Ra, PCR. Allele frequency differences were assessed by Chi-squared test; logistic regression was used to test for associations; a gene–gene interaction was conducted. Genotypic and allelic distribution of the polymorphisms was similar in our population. The estimated of the gene–gene interaction between the polymorphisms did not differ significantly. However, we observed important differences in the distribution of the alleles and genotypes of the three polymorphisms analyzed between Mestiza-Mexicanas and Maya-Mestizo women. In conclusion, we did not find an association between polymorphisms in IL-10, IL-6, and IL-1Ra and PE in Mexican-Mestizo and Maya-Mestizo women. To our knowledge, this is the first time that these three polymorphisms were analyzed together with gene–gene interaction in women with PE. PMID:23013217

  12. Polymorphisms associated with the risk of lung cancer in a healthy Mexican Mestizo population: Application of the additive model for cancer

    PubMed Central

    Pérez-Morales, Rebeca; Méndez-Ramírez, Ignacio; Castro-Hernández, Clementina; Martínez-Ramírez, Ollin C.; Gonsebatt, María Eugenia; Rubio, Julieta

    2011-01-01

    Lung cancer is the leading cause of cancer mortality in Mexico and worldwide. In the past decade, there has been an increase in the number of lung cancer cases in young people, which suggests an important role for genetic background in the etiology of this disease. In this study, we genetically characterized 16 polymorphisms in 12 low penetrance genes (AhR, CYP1A1, CYP2E1, EPHX1, GSTM1, GSTT1, GSTPI, XRCC1, ERCC2, MGMT, CCND1 and TP53) in 382 healthy Mexican Mestizos as the first step in elucidating the genetic structure of this population and identifying high risk individuals. All of the genotypes analyzed were in Hardy-Weinberg equilibrium, but different degrees of linkage were observed for polymorphisms in the CYP1A1 and EPHX1 genes. The genetic variability of this population was distributed in six clusters that were defined based on their genetic characteristics. The use of a polygenic model to assess the additive effect of low penetrance risk alleles identified combinations of risk genotypes that could be useful in predicting a predisposition to lung cancer. Estimation of the level of genetic susceptibility showed that the individual calculated risk value (iCRV) ranged from 1 to 16, with a higher iCRV indicating a greater genetic susceptibility to lung cancer. PMID:22215955

  13. Polymorphisms in the GSTT1 and GSTM1 genes are associated with increased risk of preeclampsia in the Mexican mestizo population.

    PubMed

    Sandoval-Carrillo, A; Aguilar-Duran, M; Vázquez-Alaniz, F; Castellanos-Juárez, F X; Barraza-Salas, M; Sierra-Campos, E; Téllez-Valencia, A; La Llave-León, O; Salas-Pacheco, J M

    2014-01-17

    Preeclampsia is a pregnancy-specific disorder in humans and a major cause of maternal and neonatal morbidity and mortality. Increasing evidence suggests that oxidative stress plays an important role in the pathogenesis of preeclampsia. The aim of this study was to investigate the relationship between null alleles of the glutathione S-transferases (GST) M1 and T1 genes and the risk of preeclampsia. This case-control study involved 112 preeclamptic and 233 normoevolutive pregnant women. The null polymorphisms were genotyped by multiplex polymerase chain reaction (PCR). Our results showed an increased risk of preeclampsia in patients with the GSTT1 null genotype [odds ratio (OR) = 2.21; 95% confidence interval (CI) = 1.14-4.27; P = 0.018]. Our data further showed that a combination of deletion genotypes of the GSTM1 and GSTT1 genes conferred an even higher risk of preeclampsia (OR = 4.56, 95%CI = 1.59-13.09; P = 0.005). Our results provide the first evidence suggesting that a GSTT1 null polymorphism might be associated with preeclampsia in the Mexican mestizo population, and that this risk increases with the combination of both GSTT1 and GSTM1 null polymorphisms.

  14. CYP2C9, CYP2C19, ABCB1 genetic polymorphisms and phenytoin plasma concentrations in Mexican-Mestizo patients with epilepsy.

    PubMed

    Ortega-Vázquez, A; Dorado, P; Fricke-Galindo, I; Jung-Cook, H; Monroy-Jaramillo, N; Martínez-Juárez, I E; Familiar-López, I; Peñas-Lledó, E; LLerena, A; López-López, M

    2016-06-01

    We aimed to explore the possible influence of CYP2C9 (*2, *3 and IVS8-109 A>T), CYP2C19 (*2, *3 and *17) and ABCB1 (1236C>T, 2677G>A/T and 3435C>T) on phenytoin (PHT) plasma concentrations in 64 Mexican Mestizo (MM) patients with epilepsy currently treated with PHT in mono- (n=25) and polytherapy (n=39). Genotype and allele frequencies of these variants were also estimated in 300 MM healthy volunteers. Linear regression models were used to assess associations between the dependent variables (PHT plasma concentration and dose-corrected PHT concentration) with independent variables (CYP2C9, CYP2C19 and ABCB1 genotypes, ABCB1 haplotypes, age, sex, weight, and polytherapy). In multivariate models, CYP2C9 IVS8-109 T was significantly associated with higher PHT plasma concentrations (t(64)=2.27; P=0.03). Moreover, this allele was more frequent in the supratherapeutic group as compared with the subtherapeutic group (0.13 versus 0.03, respectively; P=0.05, Fisher's exact test). Results suggest that CYP2C9 IVS8-109 T allele may decrease CYP2C9 enzymatic activity on PHT. More research is needed to confirm findings.

  15. The C677T polymorphism of the methylenetetrahydrofolate reductase gene in Mexican mestizo neural-tube defect parents, control mestizo and native populations.

    PubMed

    Dávalos, I P; Olivares, N; Castillo, M T; Cantú, J M; Ibarra, B; Sandoval, L; Morán, M C; Gallegos, M P; Chakraborty, R; Rivas, F

    2000-01-01

    The C677T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene, associated with the thermolabile form of the enzyme, has reportedly been found to be increased in neural-tube defects (NTD), though this association is still unclear. A group of 107 mestizo parents of NTD children and five control populations: 101 mestizo (M), 50 Huichol (H), 38 Tarahumara (T), 21 Purepecha (P) and 20 Caucasian (C) individuals were typed for the MTHFR C677T variant by the PCR/RFLP (HinfI) method. Genotype frequencies were in agreement with the Hardy-Weinberg expectations in all six populations. Allele frequency (%) of the C677T variant was 45 in NTD, 44 in M, 56 in H, 36 in T, 57 in P, 35 in C. Pairwise inter-population comparisons of allele frequency disclosed a very similar distribution between NTD and M groups (exact test, P=0.92). Among controls, differences between M and individual native groups were NS (0.06Mexican mestizo parents. Otherwise, C677T in Mexico is very frequent, especially in Huichol and Purepecha natives, as compared with other groups world wide.

  16. Geodetic measurements reveal similarities between post–Last Glacial Maximum and present-day mass loss from the Greenland ice sheet

    PubMed Central

    Khan, Shfaqat A.; Sasgen, Ingo; Bevis, Michael; van Dam, Tonie; Bamber, Jonathan L.; Wahr, John; Willis, Michael; Kjær, Kurt H.; Wouters, Bert; Helm, Veit; Csatho, Beata; Fleming, Kevin; Bjørk, Anders A.; Aschwanden, Andy; Knudsen, Per; Munneke, Peter Kuipers

    2016-01-01

    Accurate quantification of the millennial-scale mass balance of the Greenland ice sheet (GrIS) and its contribution to global sea-level rise remain challenging because of sparse in situ observations in key regions. Glacial isostatic adjustment (GIA) is the ongoing response of the solid Earth to ice and ocean load changes occurring since the Last Glacial Maximum (LGM; ~21 thousand years ago) and may be used to constrain the GrIS deglaciation history. We use data from the Greenland Global Positioning System network to directly measure GIA and estimate basin-wide mass changes since the LGM. Unpredicted, large GIA uplift rates of +12 mm/year are found in southeast Greenland. These rates are due to low upper mantle viscosity in the region, from when Greenland passed over the Iceland hot spot about 40 million years ago. This region of concentrated soft rheology has a profound influence on reconstructing the deglaciation history of Greenland. We reevaluate the evolution of the GrIS since LGM and obtain a loss of 1.5-m sea-level equivalent from the northwest and southeast. These same sectors are dominating modern mass loss. We suggest that the present destabilization of these marine-based sectors may increase sea level for centuries to come. Our new deglaciation history and GIA uplift estimates suggest that studies that use the Gravity Recovery and Climate Experiment satellite mission to infer present-day changes in the GrIS may have erroneously corrected for GIA and underestimated the mass loss by about 20 gigatons/year. PMID:27679819

  17. Geodetic measurements reveal similarities between post–Last Glacial Maximum and present-day mass loss from the Greenland ice sheet

    PubMed Central

    Khan, Shfaqat A.; Sasgen, Ingo; Bevis, Michael; van Dam, Tonie; Bamber, Jonathan L.; Wahr, John; Willis, Michael; Kjær, Kurt H.; Wouters, Bert; Helm, Veit; Csatho, Beata; Fleming, Kevin; Bjørk, Anders A.; Aschwanden, Andy; Knudsen, Per; Munneke, Peter Kuipers

    2016-01-01

    Accurate quantification of the millennial-scale mass balance of the Greenland ice sheet (GrIS) and its contribution to global sea-level rise remain challenging because of sparse in situ observations in key regions. Glacial isostatic adjustment (GIA) is the ongoing response of the solid Earth to ice and ocean load changes occurring since the Last Glacial Maximum (LGM; ~21 thousand years ago) and may be used to constrain the GrIS deglaciation history. We use data from the Greenland Global Positioning System network to directly measure GIA and estimate basin-wide mass changes since the LGM. Unpredicted, large GIA uplift rates of +12 mm/year are found in southeast Greenland. These rates are due to low upper mantle viscosity in the region, from when Greenland passed over the Iceland hot spot about 40 million years ago. This region of concentrated soft rheology has a profound influence on reconstructing the deglaciation history of Greenland. We reevaluate the evolution of the GrIS since LGM and obtain a loss of 1.5-m sea-level equivalent from the northwest and southeast. These same sectors are dominating modern mass loss. We suggest that the present destabilization of these marine-based sectors may increase sea level for centuries to come. Our new deglaciation history and GIA uplift estimates suggest that studies that use the Gravity Recovery and Climate Experiment satellite mission to infer present-day changes in the GrIS may have erroneously corrected for GIA and underestimated the mass loss by about 20 gigatons/year.

  18. The 482Ser of PPARGC1A and 12Pro of PPARG2 Alleles Are Associated with Reduction of Metabolic Risk Factors Even Obesity in a Mexican-Mestizo Population

    PubMed Central

    Vázquez-Del Mercado, Mónica; Guzmán-Ornelas, Milton-Omar; Corona Meraz, Fernanda-Isadora; Ríos-Ibarra, Clara-Patricia; Reyes-Serratos, Eduardo-Alejandro; Castro-Albarran, Jorge; Ruíz-Quezada, Sandra-Luz; Navarro-Hernández, Rosa-Elena

    2015-01-01

    The aim of this study was to investigate the relationship between functional polymorphisms Gly482Ser in PPARGC1A and Pro12Ala in PPARG2 with the presence of obesity and metabolic risk factors. We included 375 individuals characterized as Mexican-Mestizos and classified by the body mass index (BMI). Body dimensions and distribution of body fat were measured. The HOMA-IR and adiposity indexes were calculated. Adipokines and metabolic profile quantification were performed by ELISA and routine methods. Genetic polymorphisms were determined by polymerase chain reaction restriction fragment length polymorphism analysis. A difference between obese and nonobese subjects in polymorphism PPARGC1A distribution was observed. Among obese individuals, carriers of genotype 482Gly/Gly were observed to have decreased body fat, BMI, and body fat ratio versus 482Ser/Ser carriers and increased resistin and leptin levels in carriers Gly+ phenotype versus Gly− phenotype. Subjects with PPARG2 Ala− phenotype (genotype 12Pro/Pro) showed a decreased HOMA-IR index versus individuals with Ala+ phenotype (genotypes 12Pro/Ala plus 12Ala/Ala). We propose that, in obese Mexican-Mestizos, the combination of alleles 482Ser in PPARGC1A and 12Pro in PPARG2 represents a reduced metabolic risk profile, even when the adiposity indexes are increased. PMID:26185753

  19. The 482Ser of PPARGC1A and 12Pro of PPARG2 Alleles Are Associated with Reduction of Metabolic Risk Factors Even Obesity in a Mexican-Mestizo Population.

    PubMed

    Vázquez-Del Mercado, Mónica; Guzmán-Ornelas, Milton-Omar; Corona Meraz, Fernanda-Isadora; Ríos-Ibarra, Clara-Patricia; Reyes-Serratos, Eduardo-Alejandro; Castro-Albarran, Jorge; Ruíz-Quezada, Sandra-Luz; Navarro-Hernández, Rosa-Elena

    2015-01-01

    The aim of this study was to investigate the relationship between functional polymorphisms Gly482Ser in PPARGC1A and Pro12Ala in PPARG2 with the presence of obesity and metabolic risk factors. We included 375 individuals characterized as Mexican-Mestizos and classified by the body mass index (BMI). Body dimensions and distribution of body fat were measured. The HOMA-IR and adiposity indexes were calculated. Adipokines and metabolic profile quantification were performed by ELISA and routine methods. Genetic polymorphisms were determined by polymerase chain reaction restriction fragment length polymorphism analysis. A difference between obese and nonobese subjects in polymorphism PPARGC1A distribution was observed. Among obese individuals, carriers of genotype 482Gly/Gly were observed to have decreased body fat, BMI, and body fat ratio versus 482Ser/Ser carriers and increased resistin and leptin levels in carriers Gly+ phenotype versus Gly- phenotype. Subjects with PPARG2 Ala- phenotype (genotype 12Pro/Pro) showed a decreased HOMA-IR index versus individuals with Ala+ phenotype (genotypes 12Pro/Ala plus 12Ala/Ala). We propose that, in obese Mexican-Mestizos, the combination of alleles 482Ser in PPARGC1A and 12Pro in PPARG2 represents a reduced metabolic risk profile, even when the adiposity indexes are increased.

  20. Lexical Change in Present-Day English.

    ERIC Educational Resources Information Center

    Baron, Dennis E.

    The lexicon of present-day English is changing rapidly and regularly, and a description and explanation of this change is necessary for any comprehensive diachronic theory. An examination of a corpus of 500 new words collected during 1975 provides the basis for a typology of lexical change that both supports and suggests modifications for the…

  1. [Scientific approaches to the Mexican mestizo].

    PubMed

    Lopez-Beltran, Carlos; Deister, Vivette Garcia

    2013-06-01

    The colonial category of mestizo was an ideological tool that shaped national identity in the post-revolutionary period in Mexico. The Indian-mestizo axis functioned to organize the ethnic and political interactions of the state. Doctors and anthropologists reinforced this dual taxonomy in studies of human populations, using biomedical markers to produce differentiated descriptions of the Indian and the mestizo. Genomic descriptions have contributed both to the construction of the scientistic notion of the mestizo based on the percentage of Indian, European and African ancestry, and also to the rise of two technoscientific objects that we call the molecular mestizo and the bioinformatic mestizo. Here we describe the interactions between the ideological and scientific incarnations of the mestizo.

  2. Deep history impacts present-day ecology and biodiversity.

    PubMed

    Vitt, Laurie J; Pianka, Eric R

    2005-05-31

    Lizards and snakes putatively arose between the early Jurassic and late Triassic; they diversified worldwide and now occupy many different ecological niches, making them ideal for testing theories on the origin of ecological traits. We propose and test the "deep history hypothesis," which claims that differences in ecological traits among species arose early in evolutionary history of major clades, and that present-day assemblages are structured largely because of ancient, preexisting differences. We combine phylogenetic data with ecological data collected over nearly 40 years to reconstruct the evolution of dietary shifts in squamate reptiles. Data on diets of 184 lizard species in 12 families from 4 continents reveal significant dietary shifts at 6 major divergence points, reducing variation by 79.8%. The most striking dietary divergence (27.6%) occurred in the late Triassic, when Iguania and Scleroglossa split. These two clades occupy different regions of dietary niche space. Acquisition of chemical prey discrimination, jaw prehension, and wide foraging provided scleroglossans access to sedentary and hidden prey that are unavailable to iguanians. This cladogenic event may have profoundly influenced subsequent evolutionary history and diversification. We suggest the hypothesis that ancient events in squamate cladogenesis, rather than present-day competition, caused dietary shifts in major clades such that some lizard clades gained access to new resources, which in turn led to much of the biodiversity observed today.

  3. Common Characteristics of Models in Present-Day Scientific Practice

    ERIC Educational Resources Information Center

    Van Der Valk, Ton; Van Driel, Jan H.; De Vos, Wobbe

    2007-01-01

    Teaching the use of models in scientific research requires a description, in general terms, of how scientists actually use models in their research activities. This paper aims to arrive at defining common characteristics of models that are used in present-day scientific research. Initially, a list of common features of models and modelling, based…

  4. Upstream Material Accumulation and Meandering on Present Day Gully Evolution

    NASA Astrophysics Data System (ADS)

    Pasquon, K.; Gargani, J.; Massé, M.; Conway, S. J.; Vincendon, M.; Séjourné, A.

    2016-09-01

    Here we show the present day evolution of a martian gully during the last 4 MY: (1) non-seasonal material accumulation in the alcove, (2) seasonal evolution of meanders, (3) extension of the channel, (4) significant modifications of the debris apron.

  5. WORD-MAKING IN PRESENT-DAY ENGLISH.

    ERIC Educational Resources Information Center

    SIMONINI, R.C., JR.

    WORDS CAN BE STUDIED BY DESCRIBING THEIR ORIGIN INDUCTIVELY OR DEDUCTIVELY. EITHER WAY, A PRECISE DEFINITION OF ETYMOLOGICAL CLASSES WHICH ARE MUTUALLY EXCLUSIVE IS NEEDED. PRESENT-DAY ENGLISH IS CLASSIFIED INTO--(1) NATIVE WORDS WHICH CAN BE TRACED BACK TO THE WORD STOCK OF OLD ENGLISH, (2) LOAN WORDS NEW TO THE ENGLISH LANGUAGE WHICH HAD…

  6. The present-day number of tectonic plates

    NASA Astrophysics Data System (ADS)

    Harrison, Christopher G. A.

    2016-03-01

    The number of tectonic plates on Earth described in the literature has expanded greatly since the start of the plate tectonic era, when only about a dozen plates were considered in global models of present-day plate motions. With new techniques of more accurate earthquake epicenter locations, modern ways of measuring ocean bathymetry using swath mapping, and the use of space based geodetic techniques, there has been a huge growth in the number of plates thought to exist. The study by Bird (2003) proposed 52 plates, many of which were delineated on the basis of earthquake locations. Because of the pattern of areas of these plates, he suggested that there should be more small plates than he could identify. In this paper, I gather together publications that have proposed a total of 107 new plates, giving 159 plates in all. The largest plate (Pacific) is about 20 % of the Earth's area or 104 Mm2, and the smallest of which (Plate number 5 from Hammond et al. 2011) is only 273 km2 in area. Sorting the plates by size allows us to investigate how size varies as a function of order. There are several changes of slope in the plots of plate number organized by size against plate size order which are discussed. The sizes of the largest seven plates is constrained by the area of the Earth. A middle set of 73 plates down to an area of 97,563 km2 (the Danakil plate at number 80, is the plate of median size) follows a fairly regular pattern of plate size as a function of plate number. For smaller plates, there is a break in the slope of the plate size/plate number plot and the next 32 plates follow a pattern of plate size proposed by the models of Koehn et al. (2008) down to an area of 11,638 km2 (West Mojave plate # 112). Smaller plates do not follow any regular pattern of area as a function of plate number, probably because we have not sampled enough of these very small plates to reveal any clear pattern.

  7. Present-day climatic equivalents of European Cenozoic climates

    NASA Astrophysics Data System (ADS)

    Utescher, Torsten; Mosbrugger, Volker; Ivanov, Dimiter; Dilcher, David L.

    2009-07-01

    Recently, continental climate evolution in Central Europe over the last 45 Ma has been reconstructed from the palaeobotanical record using a Nearest Living Relative methodology (Coexistence Approach; CA). The reconstructed climate curves document in detail the transition from almost tropical conditions in the Mid-Eocene to a temperate climate at the Pliocene/Pleistocene transition. The observed climatic shifts are primarily expressed as non-proportional changes of the different variables taken into account. In the present study a published palaeoclimate data set for a total of 42 macrofloras complemented by new calculations is used as base to analyse the climatic space in which a fossil flora existed. To define these spaces CA intervals calculated for 3 temperature (mean annual temperature, cold and warm month mean) and 3 precipitation variables (mean annual precipitation, mean monthly precipitation of the driest and of the wettest month) are combined. Using a global gridded climatology (10' resolution), this climate space is then utilized to identify Recent climate analogues with respect to the variables regarded. For 18 macrofloras climatic analogue regions with respect to 6 variables are identified on the globe. For 16 macrofloras, analogues exist when three temperature parameters and mean annual precipitation are regarded. No Recent equivalents are found in 8 cases. This corroborates the assumption of the temporary existence of non-analogue climates in the Cenozoic. As shown by multivariate statistics the observed anomalies with respect to present-day conditions basically refer to high winter temperatures. Deploying a GIS, the Recent climate analogues can be presented as sets of grid cells for each flora that can be mapped on a globe. Once identified, these regions can be merged with adequate thematic layers to assess additional proxy data for the palaeofloras. To exemplify the procedure Koeppen climate type, numbers of days with ground frost, as well as

  8. A new present-day velocity field for eastern Iran

    NASA Astrophysics Data System (ADS)

    Walpersdorf, A.; Tavakoli, F.; Hatzfeld, D.; Jadidi, A.; Vergnolle, M.; Djamour, Y.; Nankali, H. R.; Sedighi, M.; Bellier, O.; Shabanian, E.

    2009-04-01

    Since 2004, extensive GPS campaigns and the upcoming Iranian permanent GPS network are monitoring the present-day deformation in eastern Iran. We present a new GPS velocity field that extends from Central Iran to the Turkmen shield and the Hellmand block on the Eurasian plate. It permits to monitor the right lateral shear across the aseismic Lut block between Central Iran and the Hellmand block, and the resulting shortening across the Kopeh Dagh mountain belt limiting NE Iran towards Turkmenistan. The present-day deformation pattern is used to verify existing tectonic models. Individual instantaneous fault slip rates are compared to short term and long term geological estimates. We find that GPS slip rates are generally coherent with short term geologic determinations (from dating of geomorphologic offsets over some 10-100 ka). Some differences with respect to long term estimates (from total geologic fault offsets and onset ages of several Ma) indicate non-constant slip rates over different time scales or that the onset of the present-day deformation presumed to 3-7 Ma in eastern Iran has to be revised.

  9. Overcoming Present-Day Powerplant Limitations Via Unconventional Engine Configurations

    NASA Technical Reports Server (NTRS)

    Meitner, Peter L.

    2006-01-01

    The Army Research Laboratory s Vehicle Technology Directorate is sponsoring the prototype development of three unconventional engine concepts - two intermittent combustion (IC) engines and one turbine engine (via SBIR (Small Business Innovative Research) contracts). The IC concepts are the Nutating Engine and the Bonner Engine, and the turbine concept is the POWER Engine. Each of the three engines offers unique and greatly improved capabilities (which cannot be achieved by present-day powerplants), while offering significant reductions in size and weight. This paper presents brief descriptions of the physical characteristics of the three engines, and discusses their performance potentials, as well as their development status.

  10. Present-day dynamic and residual topography in central Anatolia

    NASA Astrophysics Data System (ADS)

    Uluocak, Ebru Şengül; Pysklywec, Russell; Göğüş, Oğuz H.

    2016-06-01

    The Central Anatolian orogenic plateau is represented by young volcanism, rapid plateau uplift, and distinctive (past and active) tectonic deformation. In this study, we consider observational data in terms of regional present-day geodynamics in the region. The residual topography of Central Anatolia was derived to define the regional isostatic conditions according to Airy isostasy and infer the potential role of "dynamic topography". Two-dimensional thermo-mechanical forward models for coupled mantle-lithosphere flow/deformation were conducted along a N-S directional profile through the region (e.g. northern/Pontides, interior, and southern/Taurides). These models were based on seismic tomography data that provide estimates about the present-day mantle thermal structure beneath the Anatolian plate. We compare the modelling results with calculated residual topography and independent data sets of geological deformation, gravity, and high surface heat flow/widespread geothermal activity. Model results suggest that there is ˜1 km of mantle flow induced dynamic topography associated with the sub-lithospheric flow driven by the seismically-inferred mantle structure. The uprising mantle may have also driven the asthenospheric source of volcanism in the north (e.g. Galatia volcanic province) and the Cappadocia volcanic province in the south while elevating the surface in the last 10 Myrs. Our dynamic topography calculations emphasize the role of vertical forcing under other orogenic plateaux underlain by relatively thin crust and low-density asthenospheric mantle.

  11. Present-day kinematics of Adria and its southern boundary

    NASA Astrophysics Data System (ADS)

    D'Agostino, N.; Selvaggi, G.; Avallone, A.; Cheloni, D.; D'Anastasio, E.; Mantenuto, S.

    2006-12-01

    In this presentation I will review the observations that support an indipendent kinematics of the Adriatic region with respect to the Eurasia and Nubia plates. CGPS and earthquake slip vectors suggest that Adria can be divided in two independent blocks, a northern and a southern sector, whose limit can be placed across the Gargano seismic region. The Northern Adria block is currently rotating counterclockwise at ~0.2°/myr with respect to Eurasia around a pole of rotation located in the western part of the Po Plain. GPS sites in Apulia show that this region is rotating clockwise to Adria around a pole of rotation located in the middle Adriatic. The discrepanciy between the present-day kinematics and crustal deformation pattern that has dominated over Neogene and Quaternary times (convergence in the Alps and retreating subduction in the Apennines) will be discussed. By a mechanical point of view the spatial correspondence of the block boundaries with their relative poles of rotation suggest that the kinematics is controlled by the interactions between the blocks previously forming the Adriatic African promontory. These findings has important implications for the kinematics of the Ionian region and the present-day activity of the Calabrian subduction.

  12. Present-day dynamic and residual topography in Central Anatolia

    NASA Astrophysics Data System (ADS)

    Şengül Uluocak, Ebru; Pysklywec, Russell; Göǧüş, Oǧuz H.

    2016-09-01

    The Central Anatolian orogenic plateau is represented by young volcanism, rapid plateau uplift and distinctive (past and active) tectonic deformation. In this study, we consider observational data in terms of regional present-day geodynamics in the region. The residual topography of Central Anatolia was derived to define the regional isostatic conditions according to Airy isostasy and infer the potential role of `dynamic topography'. 2-D thermomechanical forward models for coupled mantle-lithosphere flow/deformation were conducted along an N-S directional profile through the region (e.g. northern/Pontides, interior and southern/Taurides). These models were based on seismic tomography data that provide estimates about the present-day mantle thermal structure beneath the Anatolian plate. We compare the modelling results with calculated residual topography and independent data sets of geological deformation, gravity and high surface heat flow/widespread geothermal activity. Model results suggest that there is ˜1 km of mantle flow induced dynamic topography associated with the sublithospheric flow driven by the seismically inferred mantle structure. The uprising mantle may have also driven the asthenospheric source of volcanism in the north (e.g. Galatia volcanic province) and the Cappadocia volcanic province in the south while elevating the surface in the last 10 Myr. Our dynamic topography calculations emphasize the role of vertical forcing under other orogenic plateaux underlain by relatively thin crust and low-density asthenospheric mantle.

  13. Stability of liquid saline water on present day Mars

    NASA Astrophysics Data System (ADS)

    Zorzano, M.-P.; Mateo-Martí, E.; Prieto-Ballesteros, O.; Osuna, S.; Renno, N.

    2009-10-01

    Perchlorate salts (mostly magnesium and sodium perchlorate) have been detected on Mars' arctic soil by the Phoenix lander, furthermore chloride salts have been found on the Meridiani and Gusev sites and on widespread deposits on the southern Martian hemisphere. The presence of these salts on the surface is not only relevant because of their ability to lower the freezing point of water, but also because they can absorb water vapor and form a liquid solution (deliquesce). We show experimentally that small amounts of sodium perchlorate (˜ 1 mg), at Mars atmospheric conditions, spontaneously absorb moisture and melt into a liquid solution growing into ˜ 1 mm liquid spheroids at temperatures as low as 225 K. Also mixtures of water ice and sodium perchlorate melt into a liquid at this temperature. Our results indicate that salty environments make liquid water to be locally and sporadically stable on present day Mars.

  14. The delayed rise of present-day mammals.

    PubMed

    Bininda-Emonds, Olaf R P; Cardillo, Marcel; Jones, Kate E; MacPhee, Ross D E; Beck, Robin M D; Grenyer, Richard; Price, Samantha A; Vos, Rutger A; Gittleman, John L; Purvis, Andy

    2007-03-29

    Did the end-Cretaceous mass extinction event, by eliminating non-avian dinosaurs and most of the existing fauna, trigger the evolutionary radiation of present-day mammals? Here we construct, date and analyse a species-level phylogeny of nearly all extant Mammalia to bring a new perspective to this question. Our analyses of how extant lineages accumulated through time show that net per-lineage diversification rates barely changed across the Cretaceous/Tertiary boundary. Instead, these rates spiked significantly with the origins of the currently recognized placental superorders and orders approximately 93 million years ago, before falling and remaining low until accelerating again throughout the Eocene and Oligocene epochs. Our results show that the phylogenetic 'fuses' leading to the explosion of extant placental orders are not only very much longer than suspected previously, but also challenge the hypothesis that the end-Cretaceous mass extinction event had a major, direct influence on the diversification of today's mammals.

  15. Network archaeology: uncovering ancient networks from present-day interactions.

    PubMed

    Navlakha, Saket; Kingsford, Carl

    2011-04-01

    What proteins interacted in a long-extinct ancestor of yeast? How have different members of a protein complex assembled together over time? Our ability to answer such questions has been limited by the unavailability of ancestral protein-protein interaction (PPI) networks. To overcome this limitation, we propose several novel algorithms to reconstruct the growth history of a present-day network. Our likelihood-based method finds a probable previous state of the graph by applying an assumed growth model backwards in time. This approach retains node identities so that the history of individual nodes can be tracked. Using this methodology, we estimate protein ages in the yeast PPI network that are in good agreement with sequence-based estimates of age and with structural features of protein complexes. Further, by comparing the quality of the inferred histories for several different growth models (duplication-mutation with complementarity, forest fire, and preferential attachment), we provide additional evidence that a duplication-based model captures many features of PPI network growth better than models designed to mimic social network growth. From the reconstructed history, we model the arrival time of extant and ancestral interactions and predict that complexes have significantly re-wired over time and that new edges tend to form within existing complexes. We also hypothesize a distribution of per-protein duplication rates, track the change of the network's clustering coefficient, and predict paralogous relationships between extant proteins that are likely to be complementary to the relationships inferred using sequence alone. Finally, we infer plausible parameters for the model, thereby predicting the relative probability of various evolutionary events. The success of these algorithms indicates that parts of the history of the yeast PPI are encoded in its present-day form. PMID:21533211

  16. ADAPTION OF NONSTANDARD PIPING COMPONENTS INTO PRESENT DAY SEISMIC CODES

    SciTech Connect

    D. T. Clark; M. J. Russell; R. E. Spears; S. R. Jensen

    2009-07-01

    With spiraling energy demand and flat energy supply, there is a need to extend the life of older nuclear reactors. This sometimes requires that existing systems be evaluated to present day seismic codes. Older reactors built in the 1960s and early 1970s often used fabricated piping components that were code compliant during their initial construction time period, but are outside the standard parameters of present-day piping codes. There are several approaches available to the analyst in evaluating these non-standard components to modern codes. The simplest approach is to use the flexibility factors and stress indices for similar standard components with the assumption that the non-standard component’s flexibility factors and stress indices will be very similar. This approach can require significant engineering judgment. A more rational approach available in Section III of the ASME Boiler and Pressure Vessel Code, which is the subject of this paper, involves calculation of flexibility factors using finite element analysis of the non-standard component. Such analysis allows modeling of geometric and material nonlinearities. Flexibility factors based on these analyses are sensitive to the load magnitudes used in their calculation, load magnitudes that need to be consistent with those produced by the linear system analyses where the flexibility factors are applied. This can lead to iteration, since the magnitude of the loads produced by the linear system analysis depend on the magnitude of the flexibility factors. After the loading applied to the nonstandard component finite element model has been matched to loads produced by the associated linear system model, the component finite element model can then be used to evaluate the performance of the component under the loads with the nonlinear analysis provisions of the Code, should the load levels lead to calculated stresses in excess of Allowable stresses. This paper details the application of component-level finite

  17. On the Stability of Liquid Water on Present Day Mars

    NASA Technical Reports Server (NTRS)

    Haberle, Robert M.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    The mean annual surface pressure and temperature on present day Mars do not allow for the long term stability of liquid water on the surface. However, theoretical arguments have been advanced that suggest liquid water could form in transient events even though it would not be in equilibrium with the environment. Using a Mars General Circulation Model, we calculate where and for how long the surface pressure and surface temperature meet the minimum requirements for this metastability of liquid water. These requirements are that the pressure and temperature must be above the triple point of water, but below its boiling point. We find that there are five regions on Mars where these requirements are periodically satisfied: in the near equatorial regions of Amazonis, Arabia, and Elysium, and in the Hellas and Argyre impact basins. Whether liquid water ever forms in these regions depends on the availability of ice and heat, and on the evaporation rate. The latter is poorly understood for low pressure CO2 environments, but is likely to be so high that melting occurs rarely, if at all. However, in the relatively recent past, surface pressures may have been higher than they are today perhaps by as much as a factor of 2 or 3. Under these circumstances melting would have been easier to achieve. We plan to undertake laboratory experiments to better understand the potential for melting in low pressure environments.

  18. The mutating preconscious archetype in present-day ecological conditions.

    PubMed

    Włoch, K

    1990-12-01

    Competition is an important force behind evolution in present-day ecological conditions, its intensity varying according to the organisms' expectations vis-à-vis resources available. On the other hand, the role of mutation in the evolutionary process can hardly be underestimated: Leading to the change of the preconsciously functioning archetype, mutation makes it impossible for the ego to realize its image. This is a consequence of the clash between the mutated, preconsciously functioning archetype and the system of ethical and moral norms functioning in the collective superego of a given population group. The type of mutation that results from the accelerated pace of evolution can be viewed as a continuity in the development of an organism's behavior. The preconsciously functioning archetype, resulting from these mutations, contains impulses and predispositions that differ markedly from the impulses and predispositions functioning in the genetically determined "pattern of behavior." In a situation where anxiety results from the inhibition of impulses and dispositions, hostility reactions are likely to occur. In its turn, reactive hostility can induce anxiety, thus creating a reaction cycle. Underlying this mechanism is the mutated, preconsciously functioning archetype, which itself is a result of the development of civilization in our contemporary world.

  19. Present-day kinematics of the East African Rift

    NASA Astrophysics Data System (ADS)

    Saria, E.; Calais, E.; Stamps, D. S.; Delvaux, D.; Hartnady, C. J. H.

    2014-04-01

    The East African Rift (EAR) is a type locale for investigating the processes that drive continental rifting and breakup. The current kinematics of this ~5000 km long divergent plate boundary between the Nubia and Somalia plates is starting to be unraveled thanks to a recent augmentation of space geodetic data in Africa. Here we use a new data set combining episodic GPS measurements with continuous measurements on the Nubian, Somalian, and Antarctic plates, together with earthquake slip vector directions and geologic indicators along the Southwest Indian Ridge to update the present-day kinematics of the EAR. We use geological and seismological data to determine the main rift faults and solve for rigid block rotations while accounting for elastic strain accumulation on locked active faults. We find that the data are best fit with a model that includes three microplates embedded within the EAR, between Nubia and Somalia (Victoria, Rovuma, and Lwandle), consistent with previous findings but with slower extension rates. We find that earthquake slip vectors provide information that is consistent with the GPS velocities and helps to significantly reduce uncertainties of plate angular velocity estimates. We also find that 3.16 Myr MORVEL average spreading rates along the Southwest Indian Ridge are systematically faster than prediction from GPS data alone. This likely indicates that outward displacement along the SWIR is larger than the default value used in the MORVEL plate motion model.

  20. Present-day microplates motion in the central Mediterranean

    NASA Astrophysics Data System (ADS)

    D'Agostino, N.

    2007-12-01

    Motion of microplates in diffuse plate boundaries often accommodates convergence between major plates. In this work we present a kinematic model for the central mediterranean sector of the Eurasia-Nubia plate boundary, derived from GPS and earthquake slip vectors, which describe the crustal motion as resulting from the interactions of two rigid microplates: Adria and Apulia-Ionia. The styles of deformation predicted by the kinematic model along the boundaries of the proposed microplates are consistent with geological observations and present significant implications for the characterization of seismically active regions in the Eurasia-Nubia plate boundary. Microplates rotation rates are succesfully reproduced by a simple slat model in which the edges of the microplates are constrained to move with the adjacent plate or microplate, suggesting a significant coupling between crustal blocks and the primary role of edge-transmitted forces as driving factor for crustal motion. These results are compared with surface wave tomographic models and other seismological observables which suggest that the rigid microplates correspond to regions of high shear wave velocities in the upper mantle and high integrated lithospheric strength. The present-day plate boundary configuration derives from the inherited Mesozoic African margin, from the rapid Neogene evolution of the Tyrrhenian subduction zone and the final fragmentation of the Adriatic promontory.

  1. Present-day sea level rise: A synthesis

    NASA Astrophysics Data System (ADS)

    Cazenave, Anny; Lombard, Alix; Llovel, William

    2008-11-01

    Measuring sea level change and understanding its causes have improved considerably in the recent years, essentially because new in situ and remote sensing data sets have become available. Here we report on the current knowledge of present-day sea level change. We briefly present observational results on sea level change from satellite altimetry since 1993 and tide gauges for the past century. We next discuss recent progress made in quantifying the processes causing sea level change on time scales ranging from years to decades, i.e., thermal expansion, land ice mass loss and land water storage change. For the 1993-2003 decade, the sum of climate-related contributions agree well (within the error bars) with the altimetry-based sea level, half of the observed rate of rise being due to ocean thermal expansion, land ice plus land waters explaining the other half. Since about 2003, thermal expansion increase has stopped, whereas the sea level continues to rise, although at a reduced rate compared to the previous decade (2.5 mm/yr versus 3.1 mm/yr). Recent increases in glacier melting and ice mass loss from the ice sheets appear able to account alone for the rise in sea level reported over the last five years.

  2. [Present day radiation diagnosis of renal tumors and cysts].

    PubMed

    Vlasov, P V; Kotliarov, P M

    1997-01-01

    The paper discusses the present-day radiation diagnosis of renal bulky formations: tumors and cysts. Based on the study of a great body of clinical data on 708 patients, the authors showed the potentialities of routine X-ray and currently available radiation techniques in the diagnosis of benign and malignant tumors and cysts of the kidney. Based on the data available in the literature and their own findings, the authors concluded that at the earliest stages of their preclinical development, tumors can be today diagnosed by a complete package of up-to-date diagnostic tools. Ultrasonic and computerized tomographies are of the highest informative value in diagnosing tumors and cystic formations. However, in some cases, a diagnosis is made via a routine excretory urography, angiography and needle biopsy. Excretory urography is of limited value for the diagnosis of renal bulky formations and it is used as an auxiliary mainly when a pathological process takes place in the renal hilus area. Angiography retains its significance as a supplementary technique. In the vast majority of cases, an accurate nosological diagnosis can be made on the basis of evaluation of the pattern of blood supply (the presence of abnormal vessels and their topographic features). The paper details the semiotics of a wide range of renal bulky processes by applying all currently available techniques of radiation diagnosis.

  3. Nitrogen evolution and present day distribution on Mars

    NASA Astrophysics Data System (ADS)

    Banin, A.; Mancinelli, R. L.

    2003-04-01

    Nitrogen is an essential element for life. Specifically, fixed nitrogen (i.e., NH_3, NH_4^+, NO_3^-, NO_2^- and N chemically bound to either inorganic or organic molecules and is releasable by hydrolysis to NH_3 or NH_4^+) is the form of nitrogen useful to living organisms. Nitrogen on present-day Mars has been analyzed only in the atmosphere. The inventory is a small fraction of the nitrogen complement presumed to have been received by the planet during its accretion. Where is the missing N? Answering this question is crucial for understanding of the probability of life evolution on Mars and for future exobiological exploration of this intriguing planet. Two main processes could have removed N from the atmosphere: 1) escape to space; 2) burial within the regolith. Non thermal escape to space due to atmospheric erosion has been suggested but its extent has not been constrained yet. No traces of organic compounds were detected in Mars soil by the Viking Landers. However, direct in situ analysis of mineral N concentration in Martian soils and rocks has not been performed yet. Due to the lack of neither biological (denitrification) nor geological (plate tectonics) recycling of N on the surface of Mars, nitrogen may have been stored in the Martian regolith as soluble inorganic salts of NO_3^- and NH_4^+, and as mineral-bound NH_4^+. Nitrates will be stable in the highly oxidized surface soil of Mars, and will tend to accumulate there. Such accumulations are observed in cold and extremely arid environments on Earth (e.g. Antarctica, the Atacama Desert). NH_4^+-N may be bound and stabilized in the soil replacing K as a structural cation in silicate minerals. In this paper we constrain the possible total N content in the Mars crust/regolith using information obtained from Mars (SNC) meteorites analyses. Further, we briefly discuss chemical, physical and, possibly, biological processes that may have affected the patterns of N distribution in the top horizons of Mars

  4. Present Day Activity of South Polar Gullies on Mars

    NASA Astrophysics Data System (ADS)

    Raack, J.; Reiss, D.; Ruesch, O.; Hiesinger, H.

    2012-04-01

    Here we report on clearly identified seasonal changes of gullies observed within the last two martian years (MY) on slopes of a south polar pit, which is located in a filled crater (diameter ~54 km) north of Sisyphi Cavi at ~68.5°S and ~1.5°E. Using new high-resolution imaging (High Resolution Imaging Science Experiment, HiRISE), temperature (Thermal Emission Spectrometer, TES) and spectral data (Compact Reconnaissance Imaging Spectrometer for Mars, CRISM; Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité, OMEGA), we analyzed the exact timing of changes of gullies and detect the possible medium (CO2, H2O or dry) and mechanism which initiate present day gully activity. Two locations in the study region with clear modifications of gullies were identified in MY 29 between LS 226° and LS 247° and between LS 209° and LS 247°. In MY 30 changes occur in both locations between LS 218° and LS 249°. Modifications are the formation of a new small apron and new deposits within the channel, both associated with the deposition of dark material. Erosion in gully alcoves or channels was not observed. TES data show temperatures between ~180 and ~240 K within the period of gully modifications. Maximum temperatures in the region rise up to ~285 K between LS ~270° and ~310°. Spectral data show a CO2-cover of the study region until LS 227°. CO2-ice free surface are spectrally observed for the first time at LS 249°. H2O was not spectrally detected in the study region and a mixture of CO2 and H2O as presented in [1] cannot be clearly detected. Unfortunately, there are no spectral data available between LS 227° and 249°. Modifications of gullies imply seasonal volatile activity. The activity can be narrowed down to occur between LS 226° and 247° at mean temperatures between ~180 and ~240 K. This is in the range of temperatures where CO2 sublimates back into the atmosphere. Based on the temperature range, the most likely candidate for the observed new

  5. Glucose-6-phosphate dehydrogenase mutations and haplotypes in Mexican Mestizos.

    PubMed

    Arámbula, E; Aguilar L, J C; Vaca, G

    2000-08-01

    In a screening for glucose-6-phosphate dehydrogenase (G-6-PD) deficiency in 1985 unrelated male subjects from the general population (Groups A and B) belonging to four states of the Pacific coast, 21 G-6-PD-deficient subjects were detected. Screening for mutations at the G-6-PD gene by PCR-restriction enzyme in these 21 G-6-PD-deficient subjects as well as in 14 G-6-PD-deficient patients with hemolytic anemia belonging to several states of Mexico showed two common G-6-PD variants: G-6-PD A-(202A/376G) (19 cases) and G-6-PD A-(376G/968C) (9 cases). In 7 individuals the mutations responsible for the enzyme deficiency remain to be determined. Furthermore, four silent polymorphic sites at the G-6-PD gene (PvuII, PstI, 1311, and NlaIII) were investigated in the 28 individuals with G-6-PD A- variants and in 137 G-6-PD normal subjects. As expected, only 10 different haplotypes were observed. To date, in our project aiming to determine the molecular basis of G-6-PD deficiency in Mexico, 60 unrelated G-6-PD-deficient Mexican males-25 in previous studies and 35 in the present work-have been studied. More than 75% of these individuals are from states of the Pacific coast (Sinaloa, Nayarit, Jalisco, Michoacán, Guerrero, Oaxaca, and Chiapas). The results show that although G-6-PD deficiency is heterogeneous at the DNA level in Mexico, only three polymorphic variants have been observed: G-6-PD A-(202A/376G) (36 cases), G-6-PD A-(376G/968C) (13 cases), and G-6-PD Seattle(844C) (2 cases). G-6-PD A- variants are relatively distributed homogeneously and both variants explain 82% of the overall prevalence of G-6-PD deficiency. The variant G-6-PD A-(202A/376G) represents 73% of the G-6-PD A- alleles. Our data also show that the variant G-6-PD A-(376G/968C)-which has been observed in Mexico in the context of two different haplotypes-is more common than previously supposed. The three polymorphic variants that we observed in Mexico are on the same haplotypes as found in subjects from Africa, the Canary Islands, and Spain.

  6. Present-day nearshore pH differentially depresses fertilization in congeneric sea urchins.

    PubMed

    Frieder, Christina A

    2014-02-01

    Ocean acidification impacts fertilization in some species of sea urchin, but whether sensitivity is great enough to be influenced by present-day pH variability has not been documented. In this study, fertilization in two congeneric sea urchins, Strongylocentrotus purpuratus and S. franciscanus, was found to be sensitive to reduced pH, <7.50, but only within a range of sperm-egg ratios that was species-specific. By further testing fertilization across a broad range of pH, pH-fertilization curves were generated and revealed that S. purpuratus was largely robust to pH, while fertilization in S. franciscanus was sensitive to even modest reductions in pH. Combining the pH-fertilization response curves with pH data collected from these species' habitat demonstrated that relative fertilization success remained high for S. purpuratus but could be as low as 79% for S. franciscanus during periods of naturally low pH. In order for S. franciscanus to maintain high fertilization success in the present and future, adequate adult densities, and thus sufficient sperm-egg ratios, will be required to negate the effects of low pH. In contrast, fertilization of S. purpuratus was robust to a broad range of pH, encompassing both present-day and future ocean acidification scenarios, even though the two congeners have similar habitats.

  7. Present-day surface deformation and tectonic insights of the extensional Ilan Plain, NE Taiwan

    NASA Astrophysics Data System (ADS)

    Kang, Chu-Chun; Chang, Chung-Pai; Siame, Lionel; Lee, Jian-Cheng

    2015-06-01

    Taiwan's mountain belt is an ideal location to address major questions regarding mechanisms of lithospheric deformation in convergent settings, mountain building processes from oceanic subduction to continental subduction, and post orogenic extension. In the northeast of this belt, the Ilan Plain is a triangular, deltaic plain characterized by a flat topography close to the sea level, and surrounded by the high mountains of the Hsuehshan Range to the northwest, and the Central Range to the southeast. Its eastern coast faces the western tip of the Okinawa Trough, the back-arc basin of the Ryukyu subduction zone. In this study, we analyzed the present-day surface deformation of the Ilan Plain, aiming at deciphering its relationships with basement faults and the regional geodynamic setting. Our approach is mainly based on surface vertical displacements revealed by Persistent Scatterer Interferometry Synthetic Aperture Radar (PSI), which indicate that there is an area of active subsidence (∼18 mm/yr) located in the southern part of the plain in probable connection with active basement faults and in agreement with previous geodetic measurements and existing geophysical data. Our PSI results also suggest that the subsidence occurring in the Ilan Plain has moved from north to south during Quaternary in relation with extrusion of the belt due to the westward propagation of the Okinawa Trough through the Taiwan Mountains.

  8. The evolution of galaxies from primeval irregulars to present-day ellipticals.

    PubMed

    Mori, Masao; Umemura, Masayuki

    2006-03-30

    Galaxy formation is believed to proceed in a 'bottom up' manner, starting with the formation of small clumps of gas and stars that then merge hierarchically into giant systems. The baryonic gas loses thermal energy by radiative cooling and falls towards the centres of the new galaxies, while supernovae blow gas out. Any realistic model therefore requires a proper treatment of these processes, but hitherto this has been far from satisfactory. Here we report a simulation that follows evolution from the earliest stages of galaxy formation through the period of dynamical relaxation, at which point the resulting galaxy is in its final form. The bubble structures of gas revealed in our simulation (for times of less than 3 x 10(8) years) resemble closely high-redshift Lyman-alpha emitters. After 10(9) years, these bodies are dominated by stellar continuum radiation and then resemble the Lyman break galaxies, which are high-redshift star-forming galaxies. At this point, the abundance of elements heavier than helium ('metallicity') appears to be solar. After 1.3 x 10(10) years, these galaxies resemble present-day ellipticals.

  9. Surface deformation induced by present-day ice melting in Svalbard

    NASA Astrophysics Data System (ADS)

    Kierulf, H. P.; Plag, H.-P.; Kohler, J.

    2009-10-01

    The vertical movement of the Earth's surface is the result of a number of internal processes in the solid Earth, tidal forces and mass redistribution in the atmosphere, oceans, terrestrial hydrosphere and cryosphere. Close to ice sheets and glaciers, the changes in the ice loads can induce large vertical motions at intraseasonal to secular timescales. The Global Positioning System (GPS) and Very Long Baseline Interferometry (VLBI) antennas in Ny-Ålesund, Svalbard that started observations in 1991 and 1995, respectively, observe vertical uplift rates on the order of 8 +/- 2 mmyr-1, which are considerably larger than those predicted by postglacial rebound (PGR) models (order 2 mmyr-1). The observations also indicate increased uplift rates starting some time in 2000. A local GPS campaign network that has been reoccupied annually since 1998, reveals a tilting away from the neighbouring glaciers. The Svalbard glaciers have been undergoing melting and retreat during the last century, with increased melting since about 2000. We compared the observed vertical motion to the motion predicted by loading models using a detailed ice model with annual time resolution as forcing. The model predictions correlate well with the observations both with respect to the interannual variations and the spatial pattern of long-term trends. The regression coefficients for predicted and observed interannual variations in height is 1.08 +/- 0.38, whereas the regression coefficient for the predicted and observed spatial pattern turns out to be 1.26 +/- 0.42. Estimates of the predicted secular trend in height due to PGR and present-day melting are on the order of 4.8 +/- 0.3 mmyr-1 and thus smaller than the observed secular trend in height. This discrepancy between predictions and observations is likely caused by the sum of errors in the secular rates determined from observations (due to technique-dependent large-scale offsets) and incomplete or erroneous models (unaccounted tectonic vertical

  10. The present-day climate of Greenland : a study with a regional climate model

    NASA Astrophysics Data System (ADS)

    Ettema, J.

    2010-04-01

    Present-day climate of Greenland Over the past 20 years, the Greenland ice sheet (GrIS) has warmed. This temperature increase can be explained by an increase in downwelling longwave radiation due to a warmer overlying atmosphere. These temperature changes are strongly correlated to changes in the large scale circulation over the ice sheet. Since 1990, the melt has also strongly increased along the ice margins, inducing significant increase in runoff. With no significant change found in the total precipitation, the GrIS surface mass balance (SMB) decreased by 12 Gt yr-1 or 7 kg m-2 yr-1 since 1990. Locally, the SMB trend reaches -90 kg m-2 yr-1 at the western and eastern ice margins. These conclusions are drawn from a modelling study by Janneke Ettema, which discusses the present-day climate and surface mass balance of the GrIS. The emphasis of this research is on understanding the underlying physical processes. Using the regional atmospheric climate model RACMO2/GR at high horizontal resolution (11km) has resulted in unprecedented detail in the ice sheet climatology and SMB. By incorporating processes such as percolation, retention and refreezing of meltwater in the surface parameterisation, the model explicitly calculates how these processes affect snow pack temperature, density and surface albedo. RACMO2/GR shows that the GrIS climate is spatially very variable. Characteristic for the ice sheet climate are the persistent katabatic winds and a quasi-permanent surface temperature deficit. Due to strong radiative cooling and turbulent heat transport towards the surface, the atmospheric boundary layer cools, providing optimal conditions for strong katabatic winds to occur. The strongest temperature deficit and wind speeds are found in the northeastern part of the ice sheet, whereas in the lower ablation zone the temperatures are more moderate due to surface melt and warm air advection. The high-resolution climate model revealed that the surface mass balance of the Gr

  11. Minimal effects of latitude on present-day speciation rates in New World birds.

    PubMed

    Rabosky, Daniel L; Title, Pascal O; Huang, Huateng

    2015-06-22

    The tropics contain far greater numbers of species than temperate regions, suggesting that rates of species formation might differ systematically between tropical and non-tropical areas. We tested this hypothesis by reconstructing the history of speciation in New World (NW) land birds using BAMM, a Bayesian framework for modelling complex evolutionary dynamics on phylogenetic trees. We estimated marginal distributions of present-day speciation rates for each of 2571 species of birds. The present-day rate of speciation varies approximately 30-fold across NW birds, but there is no difference in the rate distributions for tropical and temperate taxa. Using macroevolutionary cohort analysis, we demonstrate that clades with high tropical membership do not produce species more rapidly than temperate clades. For nearly any value of present-day speciation rate, there are far more species in the tropics than the temperate zone. Any effects of latitude on speciation rate are marginal in comparison to the dramatic variation in rates among clades.

  12. Present-day secular variations in the zonal harmonics of earth's geopotential

    NASA Technical Reports Server (NTRS)

    Mitrovica, J. X.; Peltier, W. R.

    1993-01-01

    The mathematical formulation required for predicting secular variation in the geopotential is developed for the case of a spherically symmetric, self-gravitating, viscoelastic earth model and an arbitrary surface load which can include a gravitational self-consistent ocean loading component. The theory is specifically applied to predict the present-day secular variation in the zonal harmonics of the geopotenial arising from the surface mass loading associated with the late Pleistocene glacial cycles. A procedure is outlined in which predictions of the present-day geopotential signal due to the late Pleistocene glacial cycles may be used to derive bounds on the net present-day mass flux from the Antarctic and Greenland ice sheets to the local oceans.

  13. Present-day Mars' water cycle: new views and blind perspectives

    NASA Astrophysics Data System (ADS)

    Montmessin, F.; Smith, M. D.; Fedorova, A.; Langevin, Y.; Mellon, M.

    2012-09-01

    Addressing recent cimate changes on Mars necessarily requires a succesful representation of present-day Mars water cycle. Decades of observations and modeling efforts have been conducted that now allow to elaborate a new, yet incomplete, picture, of the seasonal activity of water on Mars. This presentation explores the various observational and theoretical studies that have been conducted to date, and attempts to present a clear and detailed explanation of the major physical mechanisms that command the seasonal and geographical variability of present-day Mars water cycle, as inferred from the combined analysis of measurements and climate model simulations. Remaining issues and enigmae will be presented as well.

  14. The present day formation of apatite in Mexican continental margin sediments

    NASA Astrophysics Data System (ADS)

    Jahnke, Richard A.; Emerson, Steven R.; Roe, Kevin K.; Burnett, William C.

    1983-02-01

    Results of pore water and sediment analyses from the western Mexican continental margin strongly suggest the present day formation of apatite. The interstitial water phosphate and fluoride profiles indicate chemical removal at a depth which corresponds to a large maximum in the phosphorus content of the sediments. Apatite is identified within this maximum via X-ray diffraction but is elsewhere undetectable in the core. Radioisotopic thorium, uranium, and radium data support the conclusion that this deposit is modern. The present day depositional environment is consistent with those reported by other workers for phosphorite formation with the exception that pore water magnesium is not depleted below its seawater value.

  15. Future European Summer warming constrained by present-day seasonal cycle

    NASA Astrophysics Data System (ADS)

    Selten, Frank M.; van den Hurk, Bart; Vautard, Robert

    2014-05-01

    European summer temperatures in the CMIP5 multi-model ensemble differ by as much as 5 degrees in the present-day and this spread grows to 9 degrees by the end of this century under the RCP8.5 scenario. This spread is so large since late summer temperatures depend on a number of interacting processes with positive feedbacks during the preceding seasons that are hard to model. These include soil moisture transport and evaporation, atmospheric convection, clouds and circulation. The seasonal cycle is driven by the seasonal change in solar radiation, but these same processes and interactions play a role in the response of the seasonal cycle to an anthropogenically induced change in the radiative forcing. We hypothesize that this is the reason why we find a clear inter-model relationship between the present-day temperature and the projected warming with warm models projecting stronger warming. This hypothesis is confirmed with additional sensitivity simulations with one member of the CMIP5 ensemble (EcEarth); a change in the model formulation of the soil hydrology makes the model warmer in present-day and at the same time increases the projected warming under the RCP8.5 scenario. Based on these results we conclude that the warmest projections are unlikely as these models tend to have a warm bias in the present-day climate.

  16. Historical trauma as public narrative: A conceptual review of how history impacts present-day health

    PubMed Central

    Mohatt, Nathaniel Vincent; Thompson, Azure B.; Thai, Nghi D.; Tebes, Jacob Kraemer

    2014-01-01

    Theories of historical trauma increasingly appear in the literature on individual and community health, especially in relation to racial and ethnic minority populations and groups that experience significant health disparities. As a consequence of this rapid growth, the literature on historical trauma comprises disparate terminology and research approaches. This critical review integrates this literature in order to specify theoretical mechanisms that explain how historical trauma influences the health of individuals and communities. We argue that historical trauma functions as a public narrative for particular groups or communities that connects present-day experiences and circumstances to the trauma so as to influence health. Treating historical trauma as a public narrative shifts the research discourse away from an exclusive search for past causal variables that influence health to identifying how present-day experiences, their corresponding narratives, and their health impacts are connected to public narratives of historical trauma for a particular group or community. We discuss how the connection between historical trauma and present-day experiences, related narratives, and health impacts may function as a source of present-day distress as well as resilience. PMID:24561774

  17. The Determination of the Frequency of Syntactical Patterns in Present-Day Written Australian English.

    ERIC Educational Resources Information Center

    Beebe, Ralph D.

    Confronted with the problem of determining the frequency of syntactical patterns in present-day written Australian English, the author employs a method of analysis which produces an output in the form of a two-dimensional line diagram showing all the syntagms comprising the sentence under analysis. For the remaining problem of sorting the diagrams…

  18. Present-day kinematics of the Rivera plate and implications for tectonics in southwestern Mexico

    NASA Technical Reports Server (NTRS)

    Demets, Charles; Stein, Seth

    1990-01-01

    A model for the present-day motion of the Rivera plate relative to the North America, Cocos, and Pacific plates is derived using new data from the Pacific-Rivera rise and Rivera transform fault, together with new estimates of Pacific-Rivera motions. The results are combined with the closure-consistent NUVEL-1 global plate motion model of DeMets et al. (1990) to examine present-day deformation in southwestern Mexico. The analysis addresses several questions raised in previous studies of the Rivera plate. Namely, do plate motion data from the northern East Pacific rise require a distinct Rivera plate? Do plate kinematic data require the subduction of the Rivera plate along the seismically quiescent Acapulco trench? If so, what does the predicted subduction rate imply about the earthquake recurrence interval in the Jalisco region of southwestern Mexico?

  19. Mantle rheology and satellite signatures from present-day glacial forcings

    NASA Technical Reports Server (NTRS)

    Sabadini, Roberto; Yuen, David A.; Gasperini, Paolo

    1988-01-01

    Changes in the long-wavelength region of the earth's gravity field resulting from both present-day glacial discharges and the possible growth of the Antarctic ice sheet are considered. Significant differences in the responses between the Maxell and Burger body rheologies are found for time spans of less than 100 years. The quantitative model for predicting the secular variations of the gravitational potential, and means for incorporating glacial forcings, are described. Results are given for the excitation of the degree two harmonics. It is suggested that detailed satellite monitoring of present-day ice movements in conjunction with geodetic satellite missions may provide a reasonable alternative for the esimation of deep mantle viscosity.

  20. Convergence, divergence, and parallelism in marine biodiversity trends: Integrating present-day and fossil data

    PubMed Central

    Huang, Shan; Roy, Kaustuv; Valentine, James W.; Jablonski, David

    2015-01-01

    Paleontological data provide essential insights into the processes shaping the spatial distribution of present-day biodiversity. Here, we combine biogeographic data with the fossil record to investigate the roles of parallelism (similar diversities reached via changes from similar starting points), convergence (similar diversities reached from different starting points), and divergence in shaping the present-day latitudinal diversity gradients of marine bivalves along the two North American coasts. Although both faunas show the expected overall poleward decline in species richness, the trends differ between the coasts, and the discrepancies are not explained simply by present-day temperature differences. Instead, the fossil record indicates that both coasts have declined in overall diversity over the past 3 My, but the western Atlantic fauna suffered more severe Pliocene−Pleistocene extinction than did the eastern Pacific. Tropical western Atlantic diversity remains lower than the eastern Pacific, but warm temperate western Atlantic diversity recovered to exceed that of the temperate eastern Pacific, either through immigration or in situ origination. At the clade level, bivalve families shared by the two coasts followed a variety of paths toward today’s diversities. The drivers of these lineage-level differences remain unclear, but species with broad geographic ranges during the Pliocene were more likely than geographically restricted species to persist in the temperate zone, suggesting that past differences in geographic range sizes among clades may underlie between-coast contrasts. More detailed comparative work on regional extinction intensities and selectivities, and subsequent recoveries (by in situ speciation or immigration), is needed to better understand present-day diversity patterns and model future changes. PMID:25901312

  1. Convergence, divergence, and parallelism in marine biodiversity trends: Integrating present-day and fossil data.

    PubMed

    Huang, Shan; Roy, Kaustuv; Valentine, James W; Jablonski, David

    2015-04-21

    Paleontological data provide essential insights into the processes shaping the spatial distribution of present-day biodiversity. Here, we combine biogeographic data with the fossil record to investigate the roles of parallelism (similar diversities reached via changes from similar starting points), convergence (similar diversities reached from different starting points), and divergence in shaping the present-day latitudinal diversity gradients of marine bivalves along the two North American coasts. Although both faunas show the expected overall poleward decline in species richness, the trends differ between the coasts, and the discrepancies are not explained simply by present-day temperature differences. Instead, the fossil record indicates that both coasts have declined in overall diversity over the past 3 My, but the western Atlantic fauna suffered more severe Pliocene-Pleistocene extinction than did the eastern Pacific. Tropical western Atlantic diversity remains lower than the eastern Pacific, but warm temperate western Atlantic diversity recovered to exceed that of the temperate eastern Pacific, either through immigration or in situ origination. At the clade level, bivalve families shared by the two coasts followed a variety of paths toward today's diversities. The drivers of these lineage-level differences remain unclear, but species with broad geographic ranges during the Pliocene were more likely than geographically restricted species to persist in the temperate zone, suggesting that past differences in geographic range sizes among clades may underlie between-coast contrasts. More detailed comparative work on regional extinction intensities and selectivities, and subsequent recoveries (by in situ speciation or immigration), is needed to better understand present-day diversity patterns and model future changes. PMID:25901312

  2. Convergence, divergence, and parallelism in marine biodiversity trends: Integrating present-day and fossil data.

    PubMed

    Huang, Shan; Roy, Kaustuv; Valentine, James W; Jablonski, David

    2015-04-21

    Paleontological data provide essential insights into the processes shaping the spatial distribution of present-day biodiversity. Here, we combine biogeographic data with the fossil record to investigate the roles of parallelism (similar diversities reached via changes from similar starting points), convergence (similar diversities reached from different starting points), and divergence in shaping the present-day latitudinal diversity gradients of marine bivalves along the two North American coasts. Although both faunas show the expected overall poleward decline in species richness, the trends differ between the coasts, and the discrepancies are not explained simply by present-day temperature differences. Instead, the fossil record indicates that both coasts have declined in overall diversity over the past 3 My, but the western Atlantic fauna suffered more severe Pliocene-Pleistocene extinction than did the eastern Pacific. Tropical western Atlantic diversity remains lower than the eastern Pacific, but warm temperate western Atlantic diversity recovered to exceed that of the temperate eastern Pacific, either through immigration or in situ origination. At the clade level, bivalve families shared by the two coasts followed a variety of paths toward today's diversities. The drivers of these lineage-level differences remain unclear, but species with broad geographic ranges during the Pliocene were more likely than geographically restricted species to persist in the temperate zone, suggesting that past differences in geographic range sizes among clades may underlie between-coast contrasts. More detailed comparative work on regional extinction intensities and selectivities, and subsequent recoveries (by in situ speciation or immigration), is needed to better understand present-day diversity patterns and model future changes.

  3. Convergence, divergence, and parallelism in marine biodiversity trends: Integrating present-day and fossil data

    NASA Astrophysics Data System (ADS)

    Huang, Shan; Roy, Kaustuv; Valentine, James W.; Jablonski, David

    2015-04-01

    Paleontological data provide essential insights into the processes shaping the spatial distribution of present-day biodiversity. Here, we combine biogeographic data with the fossil record to investigate the roles of parallelism (similar diversities reached via changes from similar starting points), convergence (similar diversities reached from different starting points), and divergence in shaping the present-day latitudinal diversity gradients of marine bivalves along the two North American coasts. Although both faunas show the expected overall poleward decline in species richness, the trends differ between the coasts, and the discrepancies are not explained simply by present-day temperature differences. Instead, the fossil record indicates that both coasts have declined in overall diversity over the past 3 My, but the western Atlantic fauna suffered more severe Pliocene-Pleistocene extinction than did the eastern Pacific. Tropical western Atlantic diversity remains lower than the eastern Pacific, but warm temperate western Atlantic diversity recovered to exceed that of the temperate eastern Pacific, either through immigration or in situ origination. At the clade level, bivalve families shared by the two coasts followed a variety of paths toward today's diversities. The drivers of these lineage-level differences remain unclear, but species with broad geographic ranges during the Pliocene were more likely than geographically restricted species to persist in the temperate zone, suggesting that past differences in geographic range sizes among clades may underlie between-coast contrasts. More detailed comparative work on regional extinction intensities and selectivities, and subsequent recoveries (by in situ speciation or immigration), is needed to better understand present-day diversity patterns and model future changes.

  4. Analysis of Present Day and Future OH and Methane Lifetime in the ACCMIP Simulations

    NASA Technical Reports Server (NTRS)

    Voulgarakis, A.; Naik, V.; Lamarque, J. -F.; Shindell, D. T.; Young, P. J.; Prather, M. J.; Wild, O.; Field, R. D.; Bergmann, D.; Cameron-Smith P.; Cionni, I; Collins, W. J.; Dalsoren, S. B.; Doherty, R. M.; Eyring, V.; Faluvegi, G.; Folberth, G. A.; Horowitz, L. W.; Josse, B.; MacKenzie, I. A.; Nagashima, T.; Plummer, D. A.; Righi, M.; Rumbold, S. T.; Strode, S. A.

    2013-01-01

    Results from simulations performed for the Atmospheric Chemistry and Climate Modeling Intercomparison Project (ACCMIP) are analysed to examine how OH and methane lifetime may change from present day to the future, under different climate and emissions scenarios. Present day (2000) mean tropospheric chemical lifetime derived from the ACCMIP multi-model mean is 9.8+/-1.6 yr (9.3+/-0.9 yr when only including selected models), lower than a recent observationally-based estimate, but with a similar range to previous multi-model estimates. Future model projections are based on the four Representative Concentration Pathways (RCPs), and the results also exhibit a large range. Decreases in global methane lifetime of 4.5 +/- 9.1% are simulated for the scenario with lowest radiative forcing by 2100 (RCP 2.6), while increases of 8.5+/-10.4% are simulated for the scenario with highest radiative forcing (RCP 8.5). In this scenario, the key driver of the evolution of OH and methane lifetime is methane itself, since its concentration more than doubles by 2100 and it consumes much of the OH that exists in the troposphere. Stratospheric ozone recovery, which drives tropospheric OH decreases through photolysis modifications, also plays a partial role. In the other scenarios, where methane changes are less drastic, the interplay between various competing drivers leads to smaller and more diverse OH and methane lifetime responses, which are difficult to attribute. For all scenarios, regional OH changes are even more variable, with the most robust feature being the large decreases over the remote oceans in RCP8.5. Through a regression analysis, we suggest that differences in emissions of non-methane volatile organic compounds and in the simulation of photolysis rates may be the main factors causing the differences in simulated present day OH and methane lifetime. Diversity in predicted changes between present day and future OH was found to be associated more strongly with differences in

  5. A data-driven model of present-day glacial isostatic adjustment in North America

    NASA Astrophysics Data System (ADS)

    Simon, Karen; Riva, Riccardo

    2016-04-01

    Geodetic measurements of gravity change and vertical land motion are incorporated into an a priori model of present-day glacial isostatic adjustment (GIA) via least-squares inversion. The result is an updated model of present-day GIA wherein the final predicted signal is informed by both observational data with realistic errors, and prior knowledge of GIA inferred from forward models. This method and other similar techniques have been implemented within a limited but growing number of GIA studies (e.g., Hill et al. 2010). The combination method allows calculation of the uncertainties of predicted GIA fields, and thus offers a significant advantage over predictions from purely forward GIA models. Here, we show the results of using the combination approach to predict present-day rates of GIA in North America through the incorporation of both GPS-measured vertical land motion rates and GRACE-measured gravity observations into the prior model. In order to assess the influence of each dataset on the final GIA prediction, the vertical motion and gravimetry datasets are incorporated into the model first independently (i.e., one dataset only), then simultaneously. Because the a priori GIA model and its associated covariance are developed by averaging predictions from a suite of forward models that varies aspects of the Earth rheology and ice sheet history, the final GIA model is not independent of forward model predictions. However, we determine the sensitivity of the final model result to the prior GIA model information by using different representations of the input model covariance. We show that when both datasets are incorporated into the inversion, the final model adequately predicts available observational constraints, minimizes the uncertainty associated with the forward modelled GIA inputs, and includes a realistic estimation of the formal error associated with the GIA process. Along parts of the North American coastline, improved predictions of the long-term (kyr

  6. Utilizing Present-Day Stable Water Isotopes to Improve Paleoclimate Records from the Southeast (USA)

    NASA Astrophysics Data System (ADS)

    McKay, K. K.; Lambert, W. J.

    2015-12-01

    Present-day water isotope data are used to help interpret climate (paleo-rainfall) proxies archived in the geologic record, which can then aid in the creation of General Circulation Models (GCM). The Southeast (USA) is under-represented with respect to present-day measurement of water isotopes and high-resolution paleoclimate records, thus GCMs must extrapolate data for the region. We will evaluate water isotope data (δ18O, δD) collected and analyzed at The University of Alabama (33°13'N, 87°33'W) since June 2005. The monitoring station, central to the Southeast, was established to provide long-term water isotope data needed for reconstructing paleo-rainfall records of the region. Proxy data (e.g., δ18Ocalcite) archived in speleothems have been demonstrated to provide trustworthy information about past climate conditions; however, present-day monitoring of both local rainfall and cave dripwater are crucial. The decade-long (June 2005 - May 2015) rainfall record allows for the establishment of the relationship between water isotopes (δ18O, δD) and monthly air temperature, rainfall amount, as well as the general differences between summer and winter rainfall. Dripwater from Cathedral Caverns (34°34'N, 86°13'W), located in northeastern Alabama, has been sampled at a monthly resolution since January 2015 to determine if the water chemistry in the cave represents an annual mean for the rainfall or if it is seasonally biased. The ultimate goal of this study is to better understand how atmospheric air currents (specifically the strength/position of the Polar Jet Stream, PJS), and hence rainfall in the Southeast, varied during past periods of relative warming (e.g., Dansgaard-Oeschger events) and cooling (e.g., Heinrich events) of the Northern Hemisphere atmosphere. Future GCMs will be improved if a reliable high-resolution paleo-rainfall record can be produced for the Southeast.

  7. Comparison of lactase persistence polymorphism in ancient and present-day Hungarian populations.

    PubMed

    Nagy, Dóra; Tömöry, Gyöngyvér; Csányi, Bernadett; Bogácsi-Szabó, Erika; Czibula, Ágnes; Priskin, Katalin; Bede, Olga; Bartosiewicz, László; Downes, C Stephen; Raskó, István

    2011-06-01

    The prevalence of adult-type hypolactasia varies ethnically and geographically among populations. A C/T-13910 single nucleotide polymorphism (SNP) upstream of the lactase gene is known to be associated with lactase non-persistence in Europeans. The aim of this study was to determine the prevalence of lactase persistent and non-persistent genotypes in current Hungarian-speaking populations and in ancient bone samples of classical conquerors and commoners from the 10th-11th centuries from the Carpathian basin; 181 present-day Hungarian, 65 present-day Sekler, and 23 ancient samples were successfully genotyped for the C/T-13910 SNP by the dCAPS PCR-RFLP method. Additional mitochondrial DNA testing was also carried out. In ancient Hungarians, the T-13910 allele was present only in 11% of the population, and exclusively in commoners of European mitochondrial haplogroups who may have been of pre-Hungarian indigenous ancestry. This is despite animal domestication and dairy products having been introduced into the Carpathian basin early in the Neolithic Age. This anomaly may be explained by the Hungarian use of fermented milk products, their greater consumption of ruminant meat than milk, cultural differences, or by their having other lactase-regulating genetic polymorphisms than C/T-13910. The low prevalence of lactase persistence provides additional information on the Asian origin of Hungarians. Present-day Hungarians have been assimilated with the surrounding European populations, since they do not differ significantly from the neighboring populations in their possession of mtDNA and C/T-13910 variants.

  8. Comparison of lactase persistence polymorphism in ancient and present-day Hungarian populations.

    PubMed

    Nagy, Dóra; Tömöry, Gyöngyvér; Csányi, Bernadett; Bogácsi-Szabó, Erika; Czibula, Ágnes; Priskin, Katalin; Bede, Olga; Bartosiewicz, László; Downes, C Stephen; Raskó, István

    2011-06-01

    The prevalence of adult-type hypolactasia varies ethnically and geographically among populations. A C/T-13910 single nucleotide polymorphism (SNP) upstream of the lactase gene is known to be associated with lactase non-persistence in Europeans. The aim of this study was to determine the prevalence of lactase persistent and non-persistent genotypes in current Hungarian-speaking populations and in ancient bone samples of classical conquerors and commoners from the 10th-11th centuries from the Carpathian basin; 181 present-day Hungarian, 65 present-day Sekler, and 23 ancient samples were successfully genotyped for the C/T-13910 SNP by the dCAPS PCR-RFLP method. Additional mitochondrial DNA testing was also carried out. In ancient Hungarians, the T-13910 allele was present only in 11% of the population, and exclusively in commoners of European mitochondrial haplogroups who may have been of pre-Hungarian indigenous ancestry. This is despite animal domestication and dairy products having been introduced into the Carpathian basin early in the Neolithic Age. This anomaly may be explained by the Hungarian use of fermented milk products, their greater consumption of ruminant meat than milk, cultural differences, or by their having other lactase-regulating genetic polymorphisms than C/T-13910. The low prevalence of lactase persistence provides additional information on the Asian origin of Hungarians. Present-day Hungarians have been assimilated with the surrounding European populations, since they do not differ significantly from the neighboring populations in their possession of mtDNA and C/T-13910 variants. PMID:21365615

  9. Functional Analyses of Transcription Factor Binding Sites that Differ between Present-Day and Archaic Humans

    PubMed Central

    Weyer, Sven; Pääbo, Svante

    2016-01-01

    We analyze 25 previously identified transcription factor binding sites that carry DNA sequence changes that are present in all or nearly all present-day humans, yet occur in the ancestral state in Neandertals and Denisovans, the closest evolutionary relatives of humans. When the ancestral and derived forms of the transcription factor binding sites are tested using reporter constructs in 3 neuronal cell lines, the activity of 12 of the derived versions of transcription factor binding sites differ from the respective ancestral variants. This suggests that the majority of this class of evolutionary differences between modern humans and Neandertals may affect gene expression in at least some tissue or cell type. PMID:26454764

  10. Present-day Exposures of Water Ice in the Northern Mid-latitudes of Mars

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.; Kanner, Lisa C.

    2007-01-01

    Water ice is exposed in the martian north polar cap, but is rarely exposed beyond the cap boundary. Orbital gamma ray spectrometry data strongly imply the presence of water ice within meters of the surface at latitudes north of approximately 60deg. We have examined mid-latitude areas of the northern plains displaying residual ice-rich layers, and report evidence of present-day surface exposures of water ice. These exposures, if confirmed, could con-strain the latitudinal and temporal stability of surface ice on Mars.

  11. Chemical interactions between the present-day Martian atmosphere and surface minerals: Implications for sample return

    NASA Technical Reports Server (NTRS)

    Prinn, Ronald; Fegley, Bruce

    1988-01-01

    Thermochemical and photochemical reactions between surface minerals and present-day atmospheric constituents are predicted to produce microscopic effects on the surface of mineral grains. Relevant reactions hypothesized in the literature include conversions of silicates and volcanic glasses to clay minerals, conversion of ferrous to ferric compounds, and formation of carbonates, nitrates, and sulfates. These types of surface-atmosphere weathering of minerals, biological potential of the surface environment, and atmospheric stability in both present and past Martian epochs. It is emphasized that the product of these reactions will be observable and interpretable on the microscopic surface layers of Martian surface rocks using modern techniques with obvious implications for sample return from Mars. Macroscopic products of chemical weathering reactions in past Martian epochs are also expected in Martian surface materials. These products are expected not only as a result of reactions similar to those proceeding today but also due to aqueous reactions in past epochs in which liquid water was putatively present. It may prove very difficult or impossible, however, to determine definitively from the relic macroscopic product alone either the exact weathering process which led to its formation of the identity of its weathering parent mineral. The enormous advantages of studying the Martian chemical weathering by investigating the microscopic products of present-day chemical reactions on sample surfaces are very apparent.

  12. Chemical interactions between the present-day Martian atmosphere and surface minerals

    NASA Technical Reports Server (NTRS)

    Prinn, Ronald; Fegley, Bruce

    1987-01-01

    Thermochemical and photochemical reactions between surface minerals and present-day atmospheric constituents are predicted to produce microscopic effects on the surfaces of mineral grains. Relevant reactions hypothesized in the literature include conversions of silicates and volcanic glasses to clay minerals, conversion of ferrous to ferric compounds, and formation of carbonates, nitrates, and sulfates. These types of surface-atmosphere interactions are important for addressing issues such as chemical weathering of minerals, biological potential of the surface environment, and atmospheric stability in both present and past Martian epochs. It is emphasized that the product of these reactions will be observable and interpretable on the microscopic surface layers of Martian surface rocks using modern techniques with obvious implications for sample return from Mars. Macroscopic products of chemical weathering reactions in past Martian epochs are also expected in Martian surface material. These products are expected not only as a result of reactions similar to those proceeding today but also due to aqueous reactions in past epochs in which liquid water was putatively present. It may prove very difficult or impossible however to determine definitively from the relic macroscopic product alone either the exact weathering process which led to its formation or the identity of its weathered parent mineral. The enormous advantages of studying Martian chemical weathering by investigating the microscopic products of present-day chemical reactions on sample surfaces are very apparent.

  13. Present-day and future global bottom-up ship emission inventories including polar routes.

    PubMed

    Paxian, Andreas; Eyring, Veronika; Beer, Winfried; Sausen, Robert; Wright, Claire

    2010-02-15

    We present a global bottom-up ship emission algorithm that calculates fuel consumption, emissions, and vessel traffic densities for present-day (2006) and two future scenarios (2050) considering the opening of Arctic polar routes due to projected sea ice decline. Ship movements and actual ship engine power per individual ship from Lloyd's Marine Intelligence Unit (LMIU) ship statistics for six months in 2006 and further mean engine data from literature serve as input. The developed SeaKLIM algorithm automatically finds the most probable shipping route for each combination of start and destination port of a certain ship movement by calculating the shortest path on a predefined model grid while considering land masses, sea ice, shipping canal sizes, and climatological mean wave heights. The resulting present-day ship activity agrees well with observations. The global fuel consumption of 221 Mt in 2006 lies in the range of previously published inventories when undercounting of ship numbers in the LMIU movement database (40,055 vessels) is considered. Extrapolated to 2007 and ship numbers per ship type of the recent International Maritime Organization (IMO) estimate (100,214 vessels), a fuel consumption of 349 Mt is calculated which is in good agreement with the IMO total of 333 Mt. The future scenarios show Arctic polar routes with regional fuel consumption on the Northeast and Northwest Passage increasing by factors of up to 9 and 13 until 2050, respectively. PMID:20088494

  14. Earthquake slip vectors and estimates of present-day plate motions

    NASA Technical Reports Server (NTRS)

    Demets, Charles

    1993-01-01

    Two alternative models for present-day global plate motions are derived from subsets of the NUVEL-1 data in order to investigate the degree to which earthquake slip vectors affect the NUVEL-1 model and to provide estimates of present-day plate velocities that are independent of earthquake slip vectors. The data set used to derive the first model excludes subduction zone slip vectors. The primary purpose of this model is to demonstrate that the 240 subduction zone slip vectors in the NUVEL-1 data set do not greatly affect the plate velocities predicted by NUVEL-1. A data set that excludes all of the 724 earthquake slip vectors used to derive NUVEL-1 is used to derive the second model. This model is suitable as a reference model for kinematic studies that require plate velocity estimates unaffected by earthquake slip vectors. The slip-dependent slip vector bias along transform faults is investigated using the second model, and evidence is sought for biases in slip directions along spreading centers.

  15. A non-tectonic origin for the present day stress field in the sedimentary Paris Basin

    NASA Astrophysics Data System (ADS)

    Cornet, Francois; Magnenet, Vincent

    2016-04-01

    The large scale stress patterns observed in intraplate area is generally considered to result from far-field boundary forces that drive plate tectonics. However, no present day deformation has been detected in the Paris Basin, yet significant deviatoric stresses are measured in limestone formations observed above soft argillite layers encountered in this region at depths close to 500m. Further, the pore pressure measured in the argillite is larger than that measured in the surrounding permeable zones. These observations suggest a presently active source of stress in this sedimentary system. We propose that this stress is not related to tectonics but to pressure solution effects activated by pore pressure transients. These transients develop in the natural fracture system that affects the limestone formations. They are linked to climatic variations and involve periods that range from thousands to hundreds of thousands years. This mechanism generates time-dependent shear stresses in soft formations and explains overpressures observed in the very low permeability argillite. This mechanism may be modeled by different visco-elastic behaviors for the various formations. It outlines the influence of time dependent material properties on the present day stress field. These results imply that the viscoelastic properties of sedimentary formations raise a strong difficulty for extrapolating measured surface deformations to basement rocks in domains of very slow tectonics.

  16. Present-day and future global bottom-up ship emission inventories including polar routes.

    PubMed

    Paxian, Andreas; Eyring, Veronika; Beer, Winfried; Sausen, Robert; Wright, Claire

    2010-02-15

    We present a global bottom-up ship emission algorithm that calculates fuel consumption, emissions, and vessel traffic densities for present-day (2006) and two future scenarios (2050) considering the opening of Arctic polar routes due to projected sea ice decline. Ship movements and actual ship engine power per individual ship from Lloyd's Marine Intelligence Unit (LMIU) ship statistics for six months in 2006 and further mean engine data from literature serve as input. The developed SeaKLIM algorithm automatically finds the most probable shipping route for each combination of start and destination port of a certain ship movement by calculating the shortest path on a predefined model grid while considering land masses, sea ice, shipping canal sizes, and climatological mean wave heights. The resulting present-day ship activity agrees well with observations. The global fuel consumption of 221 Mt in 2006 lies in the range of previously published inventories when undercounting of ship numbers in the LMIU movement database (40,055 vessels) is considered. Extrapolated to 2007 and ship numbers per ship type of the recent International Maritime Organization (IMO) estimate (100,214 vessels), a fuel consumption of 349 Mt is calculated which is in good agreement with the IMO total of 333 Mt. The future scenarios show Arctic polar routes with regional fuel consumption on the Northeast and Northwest Passage increasing by factors of up to 9 and 13 until 2050, respectively.

  17. Present-day crustal deformation along the El Salvador Fault Zone from ZFESNet GPS network

    NASA Astrophysics Data System (ADS)

    Staller, Alejandra; Martínez-Díaz, José Jesús; Benito, Belén; Alonso-Henar, Jorge; Hernández, Douglas; Hernández-Rey, Román; Díaz, Manuel

    2016-02-01

    This paper presents the results and conclusions obtained from new GPS data compiled along the El Salvador Fault Zone (ESFZ). We calculated a GPS-derived horizontal velocity field representing the present-day crustal deformation rates in the ESFZ based on the analysis of 30 GPS campaign stations of the ZFESNet network, measured over a 4.5 year period from 2007 to 2012. The velocity field and subsequent strain rate analysis clearly indicate dextral strike-slip tectonics with extensional component throughout the ESFZ. Our results suggest that the boundary between the Salvadoran forearc and Caribbean blocks is a deformation zone which varies along the fault zone. We estimate that the movement between the two blocks is at least ~ 12 mm yr- 1. From west to east, this movement is variably distributed between faults or segments of the ESFZ. We propose a kinematic model with three main blocks; the Western, Central and Eastern blocks delimited by major faults. For the first time, we were able to provide a quantitative measure of the present-day horizontal geodetic slip rate of the main segments of ESFZ, ranging from ~ 2 mm yr- 1 in the east segment to ~ 8 mm yr- 1, in the west and central segments. This study contributes new kinematic and slip rate data that should be used to update and improve the seismic hazard assessments in northern Central America.

  18. The present-day geodynamics of the India-Asia collision system

    NASA Astrophysics Data System (ADS)

    Baumann, Tobias; Kaus, Boris

    2016-04-01

    We present a full 3D geodynamic model of the present-day India-Asia collision system, that includes the lithosphere and upper mantle. The model is separated into multiple tectonic blocks, for which we estimate the first order rheological properties and their impact on the dynamics of the collision system. This is done by performing systematic simulations with different rheologies to minimize the misfit to observational constraints such as the GPS-velocity field. The simulations are performed with the parallel staggered grid FD code LaMEM using a numerical resolution of at least 512x512x256 cells to resolve dynamically important shear zones reasonably well. A fundamental part of this study is the reconstruction of the 3D present-day geometry of Tibet and the adjacent regions. Our interpretations of crust and mantle lithosphere geometry are jointly based on a globally available shear wave tomography and a global crustal model. We regionally refined and modified our interpretations based on seismicity distributions and focal mechanisms and incorporated regional receiver function studies to improve the accuracy of the Moho in particular. Results suggest that we can identify at least one 'best-fit' solution in terms of rheological model properties that reproduces the observed velocity field reasonably well, including the strong rotation of the GPS velocity around the eastern syntaxis of the Himalaya. We also present model co-variances.

  19. Past- and present-day Madden-Julian Oscillation in CNRM-CM5

    NASA Astrophysics Data System (ADS)

    Song, Eun-Ji; Seo, Kyong-Hwan

    2016-04-01

    Madden-Julian Oscillation (MJO) in the past (nineteenth century) and present day (twentieth century) is examined using preindustrial and historical experiments of Centre National de Recherches Météorologiques-Coupled Models, version 5 (CNRM-CM5) in Coupled Model Intercomparison Project Phase 5 (CMIP5). The present-day MJO is stronger than the past MJO by 33% and it is ~10% more frequent. In particular, the MJO phases 4-7 signifying deep convection situated over the Maritime continent and western Pacific (WP) are considerably enhanced. These changes are due mainly to greenhouse gas forcing with little impact from nature forcing. Dynamical mechanisms for this change are investigated. A peculiar strengthening of MJO over WP comes from increased basic-state sea surface temperature (SST) over the Central Pacific (CP) and EP. The increase in precipitation over WP results from both the response to enhanced SST over CP and the inverted Walker circulation induced by the EP and CP SST increase. The latter causes a pair of anticyclonic Rossby waves straddling the equator, leading to moisture convergence over WP.

  20. Assessment of present day geomorphological dynamics to decipher landscape evolution around the Paleolithic sites of Melka Kunture, Ethiopia

    NASA Astrophysics Data System (ADS)

    Maerker, Michael; Schillaci, Calogero; Melis, Rita; Mussi, Margherita

    2014-05-01

    The area of Melka Kunture (central Ethiopia) is one of the most important clusters of Paleolithic sites in Eastern Africa. The archaeological record spans from c. 1.7 Ma onwards, with a number of stratified occurrences of Oldowan, Acheulean, Middle Stone Age and Late Stone Age industries, together with faunal remains and human fossils. However, the archaeological sites are endangered by flooding and soil erosion. The main excavation area lies close to the convergence of the Awash river with the Atabella river, one of the main tributaries of the upper Awash catchment. In the semi-arid Ethiopian highlands, gully networks develop especially in the vicinity of the active and inactive river meanders. Various erosion processes are linked to specific driving factors such as the rainfall regime, the land use/cover changes and vertic soils with a specific hydrological behaviour. It was documented in the field and by previous research that the origin of most of the man made erosion channels is due to animal pathways and car tracks. However, paleolandscape features increase the general erosion risk. Former wetland areas and deposition zones are particularly affected by soil erosion processes. Hence, the spatial distribution and characteristics of present day geomorphic processes also reveal information on the paleolandscape. In order to assess landscape evolution and present day geomorphologic dynamics, we mapped the geomorphology describing in detail the present-day slope processes at a 10.000 scale. We performed a detailed terrain analysis based on high resolution DEMs such as SRTM-X with 25m resolution and ALOS/PRISM with 10m resolution to characterize the main erosion processes and surface runoff dynamics. The latter ones are simulated using a Soil Conservation Service Curve Number method. Landuse was delineated for a larger area using ASTER 25m multispectral data. Finally, using calibrated topographic indices and a simple hydrological model we were able to detect and

  1. Biomarker patterns in present-day vegetation: consistency and variation - A study on plaggen soils

    NASA Astrophysics Data System (ADS)

    Kirkels, Frédérique; Jansen, Boris; Kalbitz, Karsten

    2013-04-01

    Biomarker patterns in present-day vegetation are commonly used as proxies to reconstruct paleo-vegetation composition, land use history and to elucidate carbon cycling. Plaggen soils are formed by diverse vegetational inputs during century-long plaggen (i.e. sod) application associated with plaggen-agriculture on poor soils in north-western Europe. This resulted in remarkably stable organic matter. Plant source identification by biomarkers could provide insight in yet unknown stabilization mechanisms and the fate of organic matter upon ongoing land use change. The current rationale behind biomarker-based source identification is that patterns observed in present-day vegetation are generally representative with little random variation. However, our knowledge on variability and consistency of biomarker patterns is yet scarce. Therefore, to assess the applicability of biomarkers for source identification in plaggen soils, we analyzed published n-alkane and n-alcohol patterns of species and their various parts which contribute(d) input to plaggen soils. We considered shrubs, trees and grass species and evaluated rescaled patterns (i.e. relative abundances in chain-length range C17-36), odd-over-even predominance (OEP) and predominant n-alkanes. In addition, we explicitly looked into potential sources of systematic variation, e.g. spatial variation (climate, site conditions), temporal variation (seasonality, ontogeny) and laboratory methodology (extraction technique: washing/shaking, Soxhlet/ASE, saponification). We found meaningful clustering of n-alkanes C27, C29, C31 and C33, allowing for clear distinction of input by shrubs, trees and grasses to plaggen soils. Combination of these homologues with complete n-alkane patterns (C17-36) and OEP enabled further differentiation, while n-alcohols patterns were less distinct. Current limitation is the lack of extended and diverse quantitative records on biomarker patterns, especially for n-alcohols, non-leaf and belowground

  2. Three-dimensional instantaneous dynamics modeling of present-day Aegean subduction

    NASA Astrophysics Data System (ADS)

    Glerum, Anne; Thieulot, Cedric; Pranger, Casper; van Hinsbergen, Douwe; Fraters, Menno; Spakman, Wim

    2015-04-01

    The Aegean region (Eastern Mediterranean) is exemplary of the interaction between crustal tectonics, plate motion, subduction and mantle flow: African subduction underneath the region has been continuous for at least the last 100 My, leading to about 2100-2500 km of subducted lithosphere residing in the mantle (van Hinsbergen et al., 2005). During this subduction, decoupled upper continental and oceanic crust accreted into a wedge of stacked nappes. In turn, these nappes have been significantly extended, predominantly during the last 25 My, due to the retreat of the African slab relative to Eurasia (van Hinsbergen and Schmid, 2012). As a first step to better understanding the coupling of the tectonic evolution of the crust and the underlying mantle dynamics, we are developing 3-D numerical models of the instantaneous dynamics of the present-day Aegean subduction system using the finite element code ASPECT (Kronbichler et al., 2012). The instantaneous models are set up with initial slab geometries derived from tomography and realistic plate boundary configurations and incorporate the major crustal weak zones of the overriding plate. Our modeling results in predictions of flow fields and stress, strain rate and rotation rate fields for the present-day tectonic setting of the Aegean region. By comparing our various model predictions to the widely available observations, such as focal mechanisms, GPS velocities and seismic anisotropy, we aim at an improved understanding of how mantle flow, subduction morphology and possibly slab segmentation, as well as the rheological behavior of the overriding plate, control present-day tectonic deformation. We expect to show preliminary results of this comparison. Kronbichler, M., Heister, T. and Bangerth, W. (2012), High Accuracy Mantle Convection Simulation through Modern Numerical Methods, Geophysical Journal International, 191, 12-29. Van Hinsbergen, D. J. J., Hafkenscheid, E., Spakman, W., Meulenkamp, J. E. and Wortel, R. (2005

  3. Present-Day Surface Changes on Mars: Implications for Recent Climate Variability and Habitability

    NASA Astrophysics Data System (ADS)

    McEwen, A. S.; Dundas, C. M.; Diniega, S.; Byrne, S.; Bridges, N. T.; Hansen, C. J.

    2012-12-01

    With the high-resolution and repeat-image capability of MRO/HiRISE, we have been documenting present-day surface activity. This activity includes seasonal defrosting (spots, fans, etc.), changes in polar deposits, new impacts, migrating sand dunes, enlargement of gullies, and a variety of slope flows. What does this tell us about possible environmental change and habitability? Perhaps the key result is that previous suggestions of recent climate change on Mars may have been somewhat exaggerated. One such suggestion is that the enlargement of pits in the south polar residual cap indicates present-day global warming. However, recent models of continuous sublimation and redeposition of the CO2 predict a suite of landforms that have been observed to exist today (Byrne, 2009, AREPS 37, 535). Another suggestion is that mid-latitude gullies formed by melting snow or shallow ice after a recent period of high obliquity, but HiRISE observations have shown rapid and widespread gully activity in the present climate (Diniega et al., 2010, Geology 38, 1047; Dundas et al., 2012, Icarus 220, 124; Dundas et al., this conference). Likewise, suggestions that Mars needed a significantly higher atmospheric density to explain the presence of well-preserved sand dunes have been countered by observations of widespread current activity (Bridges et al., 2012, Geology 40, 31; Bridges et al., 2012, Nature 485, 339). These observations do not rule out significantly different past climate conditions but do suggest that their effects were less pronounced, at least in recent times. There are features that do not appear active today; one example is the transverse aeolian ridges. Also, the mid-latitude icy lobate flows and ice-rich mantles have not shown current activity, appear to have partially sublimated, and are likely remnants of recent past climates. Ground ice excavated by new craters is observed closer to the equator than predicted for the present atmospheric water vapor content, but

  4. Present-day impact cratering rate and contemporary gully activity on Mars.

    PubMed

    Malin, Michael C; Edgett, Kenneth S; Posiolova, Liliya V; McColley, Shawn M; Dobrea, Eldar Z Noe

    2006-12-01

    The Mars Global Surveyor Mars Orbiter Camera has acquired data that establish the present-day impact cratering rate and document new deposits formed by downslope movement of material in mid-latitude gullies on Mars. Twenty impacts created craters 2 to 150 meters in diameter within an area of 21.5 x 10(6) square kilometers between May 1999 and March 2006. The values predicted by models that scale the lunar cratering rate to Mars are close to the observed rate, implying that surfaces devoid of craters are truly young and that as yet unrecognized processes of denudation must be operating. The new gully deposits, formed since August 1999, are light toned and exhibit attributes expected from emplacement aided by a fluid with the properties of liquid water: relatively long, extended, digitate distal and marginal branches, diversion around obstacles, and low relief. The observations suggest that liquid water flowed on the surface of Mars during the past decade.

  5. Larval therapy from antiquity to the present day: mechanisms of action, clinical applications and future potential

    PubMed Central

    Whitaker, Iain S; Twine, Christopher; Whitaker, Michael J; Welck, Mathew; Brown, Charles S; Shandall, Ahmed

    2007-01-01

    When modern medicine fails, it is often useful to draw ideas from ancient treatments. The therapeutic use of fly larvae to debride necrotic tissue, also known as larval therapy, maggot debridement therapy or biosurgery, dates back to the beginnings of civilisation. Despite repeatedly falling out of favour largely because of patient intolerance to the treatment, the practice of larval therapy is increasing around the world because of its efficacy, safety and simplicity. Clinical indications for larval treatment are varied, but, in particular, are wounds infected with multidrug‐resistant bacteria and the presence of significant co‐morbidities precluding surgical intervention. The flies most often used in larval therapy are the facultative calliphorids, with the greenbottle blowfly (Lucilia sericata) being the most widely used species. This review summarises the fascinating and turbulent history of larval therapy from its origin to the present day, including mechanisms of action and evidence for its clinical applications. It also explores future research directions. PMID:17551073

  6. Present-day impact cratering rate and contemporary gully activity on Mars.

    PubMed

    Malin, Michael C; Edgett, Kenneth S; Posiolova, Liliya V; McColley, Shawn M; Dobrea, Eldar Z Noe

    2006-12-01

    The Mars Global Surveyor Mars Orbiter Camera has acquired data that establish the present-day impact cratering rate and document new deposits formed by downslope movement of material in mid-latitude gullies on Mars. Twenty impacts created craters 2 to 150 meters in diameter within an area of 21.5 x 10(6) square kilometers between May 1999 and March 2006. The values predicted by models that scale the lunar cratering rate to Mars are close to the observed rate, implying that surfaces devoid of craters are truly young and that as yet unrecognized processes of denudation must be operating. The new gully deposits, formed since August 1999, are light toned and exhibit attributes expected from emplacement aided by a fluid with the properties of liquid water: relatively long, extended, digitate distal and marginal branches, diversion around obstacles, and low relief. The observations suggest that liquid water flowed on the surface of Mars during the past decade. PMID:17158321

  7. Modelling economic losses of historic and present-day high-impact winter storms in Switzerland

    NASA Astrophysics Data System (ADS)

    Welker, Christoph; Martius, Olivia; Stucki, Peter; Bresch, David; Dierer, Silke; Brönnimann, Stefan

    2015-04-01

    Windstorms can cause significant financial damage and they rank among the most hazardous meteorological hazards in Switzerland. Risk associated with windstorms involves the combination of hazardous weather conditions, such as high wind gust speeds, and socio-economic factors, such as the distribution of assets as well as their susceptibilities to damage. A sophisticated risk assessment is important in a wide range of areas and has benefits for e.g. the insurance industry. However, a sophisticated risk assessment needs a large sample of storm events for which high-resolution, quantitative meteorological and/or loss data are available. Latter is typically an aggravating factor. For present-day windstorms in Switzerland, the data basis is generally sufficient to describe the meteorological development and wind forces as well as the associated impacts. In contrast, historic windstorms are usually described by graphical depictions of the event and/or by weather and loss reports. The information on historic weather events is overall sparse and the available historic weather and loss reports mostly do not provide quantitative information. It has primarily been the field of activity of environmental historians to study historic weather extremes and their impacts. Furthermore, the scarce availability of atmospheric datasets reaching back sufficiently in time has so far limited the analysis of historic weather events. The Twentieth Century Reanalysis (20CR) ensemble dataset, a global atmospheric reanalysis currently spanning 1871 to 2012, offers potentially a very valuable resource for the analysis of historic weather events. However, the 2°×2° latitude-longitude grid of the 20CR is too coarse to realistically represent the complex orography of Switzerland, which has considerable ramifications for the representation of smaller-scale features of the surface wind field influenced by the local orography. Using the 20CR as a starting point, this study illustrates a method to

  8. Ancient human genomes suggest three ancestral populations for present-day Europeans.

    PubMed

    Lazaridis, Iosif; Patterson, Nick; Mittnik, Alissa; Renaud, Gabriel; Mallick, Swapan; Kirsanow, Karola; Sudmant, Peter H; Schraiber, Joshua G; Castellano, Sergi; Lipson, Mark; Berger, Bonnie; Economou, Christos; Bollongino, Ruth; Fu, Qiaomei; Bos, Kirsten I; Nordenfelt, Susanne; Li, Heng; de Filippo, Cesare; Prüfer, Kay; Sawyer, Susanna; Posth, Cosimo; Haak, Wolfgang; Hallgren, Fredrik; Fornander, Elin; Rohland, Nadin; Delsate, Dominique; Francken, Michael; Guinet, Jean-Michel; Wahl, Joachim; Ayodo, George; Babiker, Hamza A; Bailliet, Graciela; Balanovska, Elena; Balanovsky, Oleg; Barrantes, Ramiro; Bedoya, Gabriel; Ben-Ami, Haim; Bene, Judit; Berrada, Fouad; Bravi, Claudio M; Brisighelli, Francesca; Busby, George B J; Cali, Francesco; Churnosov, Mikhail; Cole, David E C; Corach, Daniel; Damba, Larissa; van Driem, George; Dryomov, Stanislav; Dugoujon, Jean-Michel; Fedorova, Sardana A; Gallego Romero, Irene; Gubina, Marina; Hammer, Michael; Henn, Brenna M; Hervig, Tor; Hodoglugil, Ugur; Jha, Aashish R; Karachanak-Yankova, Sena; Khusainova, Rita; Khusnutdinova, Elza; Kittles, Rick; Kivisild, Toomas; Klitz, William; Kučinskas, Vaidutis; Kushniarevich, Alena; Laredj, Leila; Litvinov, Sergey; Loukidis, Theologos; Mahley, Robert W; Melegh, Béla; Metspalu, Ene; Molina, Julio; Mountain, Joanna; Näkkäläjärvi, Klemetti; Nesheva, Desislava; Nyambo, Thomas; Osipova, Ludmila; Parik, Jüri; Platonov, Fedor; Posukh, Olga; Romano, Valentino; Rothhammer, Francisco; Rudan, Igor; Ruizbakiev, Ruslan; Sahakyan, Hovhannes; Sajantila, Antti; Salas, Antonio; Starikovskaya, Elena B; Tarekegn, Ayele; Toncheva, Draga; Turdikulova, Shahlo; Uktveryte, Ingrida; Utevska, Olga; Vasquez, René; Villena, Mercedes; Voevoda, Mikhail; Winkler, Cheryl A; Yepiskoposyan, Levon; Zalloua, Pierre; Zemunik, Tatijana; Cooper, Alan; Capelli, Cristian; Thomas, Mark G; Ruiz-Linares, Andres; Tishkoff, Sarah A; Singh, Lalji; Thangaraj, Kumarasamy; Villems, Richard; Comas, David; Sukernik, Rem; Metspalu, Mait; Meyer, Matthias; Eichler, Evan E; Burger, Joachim; Slatkin, Montgomery; Pääbo, Svante; Kelso, Janet; Reich, David; Krause, Johannes

    2014-09-18

    We sequenced the genomes of a ∼7,000-year-old farmer from Germany and eight ∼8,000-year-old hunter-gatherers from Luxembourg and Sweden. We analysed these and other ancient genomes with 2,345 contemporary humans to show that most present-day Europeans derive from at least three highly differentiated populations: west European hunter-gatherers, who contributed ancestry to all Europeans but not to Near Easterners; ancient north Eurasians related to Upper Palaeolithic Siberians, who contributed to both Europeans and Near Easterners; and early European farmers, who were mainly of Near Eastern origin but also harboured west European hunter-gatherer related ancestry. We model these populations' deep relationships and show that early European farmers had ∼44% ancestry from a 'basal Eurasian' population that split before the diversification of other non-African lineages.

  9. Ancient human genomes suggest three ancestral populations for present-day Europeans.

    PubMed

    Lazaridis, Iosif; Patterson, Nick; Mittnik, Alissa; Renaud, Gabriel; Mallick, Swapan; Kirsanow, Karola; Sudmant, Peter H; Schraiber, Joshua G; Castellano, Sergi; Lipson, Mark; Berger, Bonnie; Economou, Christos; Bollongino, Ruth; Fu, Qiaomei; Bos, Kirsten I; Nordenfelt, Susanne; Li, Heng; de Filippo, Cesare; Prüfer, Kay; Sawyer, Susanna; Posth, Cosimo; Haak, Wolfgang; Hallgren, Fredrik; Fornander, Elin; Rohland, Nadin; Delsate, Dominique; Francken, Michael; Guinet, Jean-Michel; Wahl, Joachim; Ayodo, George; Babiker, Hamza A; Bailliet, Graciela; Balanovska, Elena; Balanovsky, Oleg; Barrantes, Ramiro; Bedoya, Gabriel; Ben-Ami, Haim; Bene, Judit; Berrada, Fouad; Bravi, Claudio M; Brisighelli, Francesca; Busby, George B J; Cali, Francesco; Churnosov, Mikhail; Cole, David E C; Corach, Daniel; Damba, Larissa; van Driem, George; Dryomov, Stanislav; Dugoujon, Jean-Michel; Fedorova, Sardana A; Gallego Romero, Irene; Gubina, Marina; Hammer, Michael; Henn, Brenna M; Hervig, Tor; Hodoglugil, Ugur; Jha, Aashish R; Karachanak-Yankova, Sena; Khusainova, Rita; Khusnutdinova, Elza; Kittles, Rick; Kivisild, Toomas; Klitz, William; Kučinskas, Vaidutis; Kushniarevich, Alena; Laredj, Leila; Litvinov, Sergey; Loukidis, Theologos; Mahley, Robert W; Melegh, Béla; Metspalu, Ene; Molina, Julio; Mountain, Joanna; Näkkäläjärvi, Klemetti; Nesheva, Desislava; Nyambo, Thomas; Osipova, Ludmila; Parik, Jüri; Platonov, Fedor; Posukh, Olga; Romano, Valentino; Rothhammer, Francisco; Rudan, Igor; Ruizbakiev, Ruslan; Sahakyan, Hovhannes; Sajantila, Antti; Salas, Antonio; Starikovskaya, Elena B; Tarekegn, Ayele; Toncheva, Draga; Turdikulova, Shahlo; Uktveryte, Ingrida; Utevska, Olga; Vasquez, René; Villena, Mercedes; Voevoda, Mikhail; Winkler, Cheryl A; Yepiskoposyan, Levon; Zalloua, Pierre; Zemunik, Tatijana; Cooper, Alan; Capelli, Cristian; Thomas, Mark G; Ruiz-Linares, Andres; Tishkoff, Sarah A; Singh, Lalji; Thangaraj, Kumarasamy; Villems, Richard; Comas, David; Sukernik, Rem; Metspalu, Mait; Meyer, Matthias; Eichler, Evan E; Burger, Joachim; Slatkin, Montgomery; Pääbo, Svante; Kelso, Janet; Reich, David; Krause, Johannes

    2014-09-18

    We sequenced the genomes of a ∼7,000-year-old farmer from Germany and eight ∼8,000-year-old hunter-gatherers from Luxembourg and Sweden. We analysed these and other ancient genomes with 2,345 contemporary humans to show that most present-day Europeans derive from at least three highly differentiated populations: west European hunter-gatherers, who contributed ancestry to all Europeans but not to Near Easterners; ancient north Eurasians related to Upper Palaeolithic Siberians, who contributed to both Europeans and Near Easterners; and early European farmers, who were mainly of Near Eastern origin but also harboured west European hunter-gatherer related ancestry. We model these populations' deep relationships and show that early European farmers had ∼44% ancestry from a 'basal Eurasian' population that split before the diversification of other non-African lineages. PMID:25230663

  10. The Combined Landscape of Denisovan and Neanderthal Ancestry in Present-Day Humans.

    PubMed

    Sankararaman, Sriram; Mallick, Swapan; Patterson, Nick; Reich, David

    2016-05-01

    Some present-day humans derive up to ∼5% [1] of their ancestry from archaic Denisovans, an even larger proportion than the ∼2% from Neanderthals [2]. We developed methods that can disambiguate the locations of segments of Denisovan and Neanderthal ancestry in present-day humans and applied them to 257 high-coverage genomes from 120 diverse populations, among which were 20 individual Oceanians with high Denisovan ancestry [3]. In Oceanians, the average size of Denisovan fragments is larger than Neanderthal fragments, implying a more recent average date of Denisovan admixture in the history of these populations (p = 0.00004). We document more Denisovan ancestry in South Asia than is expected based on existing models of history, reflecting a previously undocumented mixture related to archaic humans (p = 0.0013). Denisovan ancestry, just like Neanderthal ancestry, has been deleterious on a modern human genetic background, as reflected by its depletion near genes. Finally, the reduction of both archaic ancestries is especially pronounced on chromosome X and near genes more highly expressed in testes than other tissues (p = 1.2 × 10(-7) to 3.2 × 10(-7) for Denisovan and 2.2 × 10(-3) to 2.9 × 10(-3) for Neanderthal ancestry even after controlling for differences in level of selective constraint across gene classes). This suggests that reduced male fertility may be a general feature of mixtures of human populations diverged by >500,000 years.

  11. The Combined Landscape of Denisovan and Neanderthal Ancestry in Present-Day Humans.

    PubMed

    Sankararaman, Sriram; Mallick, Swapan; Patterson, Nick; Reich, David

    2016-05-01

    Some present-day humans derive up to ∼5% [1] of their ancestry from archaic Denisovans, an even larger proportion than the ∼2% from Neanderthals [2]. We developed methods that can disambiguate the locations of segments of Denisovan and Neanderthal ancestry in present-day humans and applied them to 257 high-coverage genomes from 120 diverse populations, among which were 20 individual Oceanians with high Denisovan ancestry [3]. In Oceanians, the average size of Denisovan fragments is larger than Neanderthal fragments, implying a more recent average date of Denisovan admixture in the history of these populations (p = 0.00004). We document more Denisovan ancestry in South Asia than is expected based on existing models of history, reflecting a previously undocumented mixture related to archaic humans (p = 0.0013). Denisovan ancestry, just like Neanderthal ancestry, has been deleterious on a modern human genetic background, as reflected by its depletion near genes. Finally, the reduction of both archaic ancestries is especially pronounced on chromosome X and near genes more highly expressed in testes than other tissues (p = 1.2 × 10(-7) to 3.2 × 10(-7) for Denisovan and 2.2 × 10(-3) to 2.9 × 10(-3) for Neanderthal ancestry even after controlling for differences in level of selective constraint across gene classes). This suggests that reduced male fertility may be a general feature of mixtures of human populations diverged by >500,000 years. PMID:27032491

  12. How large are present-day heat flow variations across Mars' surface?

    NASA Astrophysics Data System (ADS)

    Plesa, Ana-Catalina; Tosi, Nicola; Grott, Matthias; Breuer, Doris

    2015-04-01

    The upcoming InSight (Interior exploration using Seismic Investigations, Geodesy and Heat Transport) mission, to be launched in 2016, will carry the first in-situ Martian heat flow measurement and provide an important baseline to constrain the present-day heat budget of the planet and, in turn, the thermal and chemical evolution of its interior. Currently, the Earth and the Moon are the only bodies on which in-situ surface heat flow measurements have been performed. Here, strong spatial variations of the surface heat flow are primarily caused by plate tectonics and the heterogeneous distribution of heat producing elements over the surface (e.g., the so-called Procellarum KREEP Terrane PKT on the lunar nearside). In the absence of plate-tectonics and large-scale geochemical anomalies, on Mars, surface heat flow is expected to vary less with geological location, being mainly influenced by variations in the thickness and HPE content of the crust [1], and by mantle plumes [2]. We have tested this assumption by running thermal evolution models for Mars in 3D spherical geometry, using the mantle convection code Gaia [3]. In our calculations, we employ a crust of fixed thickness with a north-south dichotomy in crustal thickness, a low conductivity compared to the mantle and enriched in radiogenic heat producing elements. Our results show that including compressibility effects, phase transitions and different core sizes, surface heat flow variations are mainly dominated by the crust contribution, unless the mantle viscosity increases more than three orders of magnitude with depth. In the latter case, heat flow variations due to mantle upwellings are ~ 8 mW/m2 relative to surface average and remain confined to limited surface regions. Both surface heat flow variations on Mars obtained from numerical models and the heat flow measurement planned for the InSight mission will permit to address the question of a possible plume underneath Elysium and also to test the feasibility

  13. Simulation of Net Infiltration for Present-Day and Potential Future Climates

    SciTech Connect

    D. Levitt

    2004-11-09

    The purpose of this model report is to document the infiltration model used to estimate upper-bound, mean, and lower-bound spatially-distributed average annual net infiltration rates for present-day and potential future climates at Yucca Mountain, Nevada. Net infiltration is the component of infiltrated precipitation, snowmelt, or surface water run-on that has percolated below the zone of evapotranspiration as defined by the depth of the effective root zone. The estimates of net infiltration are primarily used for defining the upper boundary condition for the site-scale three-dimensional unsaturated zone (UZ) model. The UZ flow model is one of several process models abstracted by the total system performance assessment (TSPA) model used to evaluate performance of the repository at Yucca Mountain, Nevada. The net-infiltration model is important for assessing repository-system performance because output from this model provides the upper boundary condition for the UZ flow model used to generate flow fields; water percolating downward from the UZ will be the principal means by which radionuclides are potentially released to the saturated zone (SZ). The SZ is the principal pathway to the biosphere where the reasonably maximally exposed individual (RMEI) is exposed to radionuclides.

  14. Present-day deformation of northern Pakistan from Salt Ranges to Karakorum Ranges

    NASA Astrophysics Data System (ADS)

    Jouanne, F.; Awan, A.; Pêcher, A.; Kausar, A.; Mugnier, J. L.; Khan, I.; Khan, N. A.; Van Melle, J.

    2014-03-01

    Episodic GPS measurements are used to quantify the present-day velocity field in the northwestern Himalaya from the southern Pamir to the Himalayan foreland. We report large postseismic displacements following the 2005 Kashmir earthquake and several mm/yr thrusting of the central segment of the Salt Ranges and Potwar Plateau over the foreland, westward thrusting of Nanga Parbat above the Kohistan Plateau, and ~12 mm/yr SSE velocities of the Karakorum Ranges and of the Deosai and Kohistan Plateaus relative to the Indian Plate. Numerical simulations allow to determine a first approximation of slip along active faults: (1) substantial creep of ~87 mm/yr between 2006 and 2012 along the flat northeast of the Balakot-Bagh Thrust affected by the 2005 earthquake; (2) ~5 mm/yr slip of the central segment of the Salt Ranges and Potwar Plateau, whereas their western boundaries are clearly inactive over the time span covered by our measurements; (3) 13 mm/yr ductile slip along the Main Himalayan Thrust modeled by a dislocation dipping 7° northward, locked at a depth of 15 km; and (4) ~20 mm/yr slip along the shear zone forming the western boundary of Nanga Parbat, between depths of 1.6 and 6.5 km. Residuals velocities suggest the existence of left-lateral strike slip along the Jhelum Fault.

  15. The history of time and frequency from antiquity to the present day

    NASA Astrophysics Data System (ADS)

    Levine, Judah

    2016-04-01

    I will discuss the evolution of the definitions of time, time interval, and frequency from antiquity to the present day. The earliest definitions of these parameters were based on a time interval defined by widely observed apparent astronomical phenomena, so that techniques of time distribution were not necessary. With this definition, both time, as measured by clocks, and frequency, as realized by some device, were derived quantities. On the other hand, the fundamental parameter today is a frequency based on the properties of atoms, so that the situation is reversed and time and time interval are now derived quantities. I will discuss the evolution of this transition and its consequences. In addition, the international standards of both time and frequency are currently realized by combining the data from a large number of devices located at many different laboratories, and this combination depends on (and is often limited by) measurements of the times of clocks located at widely-separated laboratories. I will discuss how these measurements are performed and how the techniques have evolved over time.

  16. Challenges in constraining anthropogenic aerosol effects on cloud radiative forcing using present-day spatiotemporal variability.

    PubMed

    Ghan, Steven; Wang, Minghuai; Zhang, Shipeng; Ferrachat, Sylvaine; Gettelman, Andrew; Griesfeller, Jan; Kipling, Zak; Lohmann, Ulrike; Morrison, Hugh; Neubauer, David; Partridge, Daniel G; Stier, Philip; Takemura, Toshihiko; Wang, Hailong; Zhang, Kai

    2016-05-24

    A large number of processes are involved in the chain from emissions of aerosol precursor gases and primary particles to impacts on cloud radiative forcing. Those processes are manifest in a number of relationships that can be expressed as factors dlnX/dlnY driving aerosol effects on cloud radiative forcing. These factors include the relationships between cloud condensation nuclei (CCN) concentration and emissions, droplet number and CCN concentration, cloud fraction and droplet number, cloud optical depth and droplet number, and cloud radiative forcing and cloud optical depth. The relationship between cloud optical depth and droplet number can be further decomposed into the sum of two terms involving the relationship of droplet effective radius and cloud liquid water path with droplet number. These relationships can be constrained using observations of recent spatial and temporal variability of these quantities. However, we are most interested in the radiative forcing since the preindustrial era. Because few relevant measurements are available from that era, relationships from recent variability have been assumed to be applicable to the preindustrial to present-day change. Our analysis of Aerosol Comparisons between Observations and Models (AeroCom) model simulations suggests that estimates of relationships from recent variability are poor constraints on relationships from anthropogenic change for some terms, with even the sign of some relationships differing in many regions. Proxies connecting recent spatial/temporal variability to anthropogenic change, or sustained measurements in regions where emissions have changed, are needed to constrain estimates of anthropogenic aerosol impacts on cloud radiative forcing.

  17. [Psychiatry during National Socialism: historical knowledge, implications for present day ethical debates].

    PubMed

    Roelcke, V

    2010-11-01

    This contribution is a synthesis of the results of historical research on psychiatry during the Nazi period and some implications for present day debates in medical ethics. The focus is on three issues: the relationship between physicians and the state, the impact of eugenically and economically motivated health and social policies for psychiatry (e.g. forced sterilization, patient killing/euthanasia) and psychiatric research. Three myths are deconstructed: 1) that medical atrocities were imposed from above by Nazi politicians on apolitical physicians, 2) that mass sterilization and patient killing had nothing to do with contemporary state of the art of medical reasoning and practice and 3) that ethically unacceptable research on psychiatric patients had nothing to do with the contemporary state of the art of biomedical sciences. It is argued that the findings on these issues of Nazi medicine are not specific to Germany and the period between 1933 and 1945 but they were the extreme manifestations of some potential problems implicit in modern medicine in general.

  18. Present-day stress field in the Gibraltar Arc (western Mediterranean)

    NASA Astrophysics Data System (ADS)

    FernáNdez-IbáñEz, F.; Soto, J. I.; Zoback, M. D.; Morales, J.

    2007-08-01

    The Gibraltar Arc in the western Mediterranean consists of the Betic and Rif Alpine chains and the Alboran Sea Basin. Four types of stress indicators (wellbore breakouts, earthquake focal plane mechanisms, young geologic fault slip data, and hydraulic fracture orientations) indicate a regional NW-SE compressive stress field resulting from Africa-Eurasia plate convergence. In some particular regions, deviations of SHmax are observed with respect to the regional stress field. They are gentle-to-moderate (22°-36°) anticlockwise rotations located along the North Alboran margin and moderate-to-significant (36°-78°) clockwise rotations around the Trans-Alboran Shear Zone (TASZ). This is a broad fault zone composed of different left-lateral strike-slip fault segments running from the eastern Betics to the Alhoceima region in the Rif and resulting in a major bathymetric high in the Alboran Sea (the Alboran Ridge fault zone). Some of these stress rotations appear to be controlled by steep gradients of crustal thickness variation across the North Alboran margin and/or differential loading imposed by thick sedimentary accumulations in basin depocenters parallel to the shoreline. Other stress perturbations may be related to active left-lateral, strike-slip deformation within the TASZ that crosscuts the entire orogenic arc on a NE-SW trend and represents a key element to understand present-day deformation partitioning in the western Mediterranean.

  19. Differences between Last Glacial Maximum and present-day temperature and precipitation in southern South America

    NASA Astrophysics Data System (ADS)

    Berman, Ana Laura; Silvestri, Gabriel E.; Tonello, Marcela S.

    2016-10-01

    This paper is the first analysis of differences between Last Glacial Maximum (LGM) and present climates in southern South America considering the state-of-the-art PMIP3 paleoclimatic models. The study is focused on characteristics of temperature and precipitation over the portion of the continent to the south of 20°S at both sides of the Andes Cordillera. Results demonstrate that model outputs coincide with glacial conditions inferred from the very few paleorecords available in the region. Consequently, these models are a valuable tool for inferring additional conditions in areas where there is a lack of proxy information allowing the reconstruction of the past climate at regional scales. The analyzed PMIP3 models expose an LGM cooling of ∼2-5 °C throughout the year over almost all southern South America but differences are even more pronounced in areas around the southern Andes. Models also suggest that LGM precipitation was substantially lower than present over the portion of southern South America to the east of the Andes inferring reductions of ∼20-30% with respect to present-day values in subtropical areas and ∼40-50% in the southern tip of the continent.

  20. Global hotspots in the present-day distribution of ancient animal and plant lineages

    PubMed Central

    Procheş, Şerban; Ramdhani, Syd; Perera, Sandun J.; Ali, Jason R.; Gairola, Sanjay

    2015-01-01

    The current distribution of biotic lineages that emerged in the deep time has both theoretical and practical implications, in particular for understanding the processes that have forged present-day biodiversity and informing local and regional-scale conservation efforts. To date however, there has been no examination of such patterns globally across taxa and geological time. Here we map the diversity of selected extant seed plant and tetrapod vertebrate lineages that were already in existence either in the latest Triassic or latest Cretaceous. For Triassic-age linages, we find concentrations in several regions – both tropical and temperate – parts of North America, Europe, East and South-east Asia, northern South America, and New Zealand. With Cretaceous-age lineages, high values are relatively uniformly distributed across the tropics, with peak the values along the Andes, in South-east Asia and Queensland, but also in the temperate Cape Mountains. These patterns result from a combination of factors, including land area, geographic isolation, climate stability and mass extinction survival ability. While the need to protect many of these lineages has been long recognised, a spatially-explicit approach is critical for understanding and maintaining the factors responsible for their persistence, and this will need to be taken forward across finer scales. PMID:26498226

  1. Present-day climate near the Bunker Cave (Germany): comparison of model simulations to observations.

    NASA Astrophysics Data System (ADS)

    Langebroek, Petra M.; Werner, Martin; Lohmann, Gerrit

    2010-05-01

    Because of their high temporal resolution and good preservation, speleothem records are often used as indicators for past climatic conditions. During the last years, substantial scientific progress has been made on the interpretation of these proxy records in terms of temperature and precipitation changes. Unfortunately, the link between climatic conditions within the cave (as depicted from the speleothems) to the climate outside the cave is not straightforward for many cave locations. In order to improve this connection, it is important to have accurate speleothems data as well as high-resolution large-scale climate data. In this study we focus on the latter problem. Within the framework of the DAPHNE ("Dated Speleothems Archives of the Paleoenvironment") Project we investigated available climate measurements (stations from the Deutsche Wetterdienst and from the Global Network of Isotopes in Precipitation) in the region surrounding the Bunker Cave, which is located close to Iserlohn in Germany. These measurements are compared, on a larger scale, to reanalysis data (ECMWF-ERA40) and simulation results from an atmospheric general circulation model with isotope diagnostics built into the models hydrological cycle (ECHAM). We used statistical downscaling to establish a connection between the large-scale information and the local climate surrounding the Bunker Cave. Understanding how the local present-day climate above the cave is influenced will largely improve our knowledge of palaeoclimate as derived from the speleothem records.

  2. Cannabis careers revisited: applying Howard S. Becker's theory to present-day cannabis use.

    PubMed

    Järvinen, Margaretha; Ravn, Signe

    2014-01-01

    A considerable part of today's sociological research on recreational drug use is (explicitly or implicitly) inspired by Howard Becker's classical model of deviant careers. The aim of the present paper is to directly apply Becker's theory to empirical data on present-day cannabis use and to suggest a revision of the theory. As part of this, we propose a stretch of the sociological approach represented by Becker and followers in order to include, not only recreational drug use, but also use for which young people have sought treatment. The paper is based on 30 qualitative interviews with young people in treatment for cannabis problems in Copenhagen, Denmark. We suggest a revision of Becker's career model in relation to four aspects: initiation of cannabis use, differentiation between socially integrated and individualised, disintegrated use, social control from non-users, and the users' moral stance on cannabis. A central point of the paper is that social interaction may both motivate cannabis use, as Becker proposed, and serve as a protective factor against extensive, problematic use.

  3. Recovery of a geocentric reference frame using the present-day GPS system

    NASA Technical Reports Server (NTRS)

    Malla, Rajendra P.; Wu, Sien-Chong

    1990-01-01

    A geocentric reference frame adopts the center of mass of the earth as the origin of the coordinate axes. The center of mass of the earth is the natural and unambiguous origin of a geocentric satellite dynamical system. But in practice a kinematically obtained terrestrial reference frame may assume an origin other than the geocenter. The establishment of a geocentric reference frame, to which all relevant observations and results can be referred and in which geodynamic theories or models for the dynamic behavior of earth can be formulated, requires the ability to accurately recover a given coordinate frame origin offset from the geocenter. GPS measurements, because of their abundance and broad distribution, provide a powerful tool to obtain this origin offset in a short period of time. Two effective strategies have been devised. Data from the First Central And South America (Casa Uno) geodynamics experiment has been studied, in order to demonstrate the ability of recovering the geocenter location with present day GPS satellites and receivers.

  4. Present-day genetic structure of Atlantic salmon (Salmo salar) in Icelandic rivers and ice-cap retreat models.

    PubMed

    Olafsson, Kristinn; Pampoulie, Christophe; Hjorleifsdottir, Sigridur; Gudjonsson, Sigurdur; Hreggvidsson, Gudmundur O

    2014-01-01

    Due to an improved understanding of past climatological conditions, it has now become possible to study the potential concordance between former climatological models and present-day genetic structure. Genetic variability was assessed in 26 samples from different rivers of Atlantic salmon in Iceland (total of 2,352 individuals), using 15 microsatellite loci. F-statistics revealed significant differences between the majority of the populations that were sampled. Bayesian cluster analyses using both prior information and no prior information on sampling location revealed the presence of two distinguishable genetic pools - namely, the Northern (Group 1) and Southern (Group 2) regions of Iceland. Furthermore, the random permutation of different allele sizes among allelic states revealed a significant mutational component to the genetic differentiation at four microsatellite loci (SsaD144, Ssa171, SSsp2201 and SsaF3), and supported the proposition of a historical origin behind the observed variation. The estimated time of divergence, using two different ABC methods, suggested that the observed genetic pattern originated from between the Last Glacial Maximum to the Younger Dryas, which serves as additional evidence of the relative immaturity of Icelandic fish populations, on account of the re-colonisation of this young environment following the Last Glacial Maximum. Additional analyses suggested the presence of several genetic entities which were likely to originate from the original groups detected. PMID:24498283

  5. Three-dimensional velocity field of present-day crustal motion of the Tibetan Plateau derived from GPS measurements

    NASA Astrophysics Data System (ADS)

    Liang, Shiming; Gan, Weijun; Shen, Chuanzheng; Xiao, Genru; Liu, Jing; Chen, Weitao; Ding, Xiaoguang; Zhou, Deming

    2013-10-01

    the measurements of 750 GPS stations around the Tibetan Plateau for over 10 years since 1999, we derived a high-resolution 3-D velocity field for the present-day crustal movement of the plateau. The horizontal velocity field relative to stable Eurasia displays in details the crustal movement and tectonic deformation features of the India-Eurasia continental collision zone with thrust compression, lateral extrusion, and clockwise rotation. The vertical velocity field reveals that the Tibetan Plateau is continuing to rise as a whole relative to its stable north neighbor. However, in some subregions, uplift is insignificant or even negative. The main features of the vertical crustal deformation of the plateau are the following: (a) The Himalayan range is still rising at a rate of ~2 mm/yr. The uplift rate is ~6 mm/yr with respect to the south foot of the Himalayan range. (b) The middle eastern plateau has a typical uplift rate between 1 and 2 mm/yr, and some high mountain ranges in this area, like the Longmen Shan and Gongga Shan, have surprising uplift rates as large as 2-3mm/yr. (c) In the middle southern plateau, there is a basin and endorheic subregion with a series of NS striking normal faults, showing obvious sinking with the rates between 0 and -3 mm/yr. (d) The present-day rising and sinking subregions generally correspond well to the Cenozoic orogenic belts and basins, respectively. (e) At the southeastern corner of the plateau. There is an apparent trend that the uplift rate is gradually decreasing from between 0.8 and 2.3 mm/yr in the inner plateau to between -0.5 and -1.6 mm/yr outside the plateau, with the decrease of terrain height.

  6. 3D velocity field of present-day crustal motion of the Tibetan Plateau derived from GPS measurements

    NASA Astrophysics Data System (ADS)

    Gan, W.

    2013-12-01

    Using the measurements of 564 GPS stations around the Tibetan plateau for over 10 years, we derived a high-resolution 3D velocity field for the present-day crustal motion of the plateau with improved precision. The horizontal velocity field of the plateau relative to stable Eurasia displays in details the crustal movement and tectonic deformation features of India-Eurasia continental collision zone with thrust compression, lateral extrusion and clockwise rotation. The vertical velocities reveal that the plateau is still rising as a whole relative to its stable north neighbor. However, in some subregions uplift is insignificant or even negative. The main features of the vertical crustal deformation are: a) The Himalayan range is rising at a rate of ~3mm/yr, the most significant in the whole plateau. The uplift rate of the Himalayan range is ~6mm/a relative to its south foot; b) The mid-eastern plateau has an typical uplift rate between 1~2 mm/a, and some high mountain ranges in this area have surprising uplift rates as large as 2~3mm/a; c) In the mid-southern plateau, there is a basin and endorheic subregion with a series of NE striking normal faults, showing obvious sinking with the rates between 0 to -4mm/a; d) The present-day rising and sinking subregions generally correspond well to the Cenozoic orogenic belts and basins, respectively; e) At the southeastern corner of the plateau, although the horizontal velocity field demonstrates an outstanding clockwise rotation and fan-like front of a flow zone, the vertical velocity field does not show a general uplift or incline trend. Horizontal GPS velocities of the Tibetan plateau relative to stable Eurasia Vertical GPS velocities of the Tibetan plateau relative to its stable northern neighbor

  7. Relationship between the present-day stress field and plate boundary forces in the Pacific Northwest

    USGS Publications Warehouse

    Geist, E.L.

    1996-01-01

    The relationship between plate boundary forces and the observed stress field in the Pacific Northwest is established using numerical models of continental deformation. Because the orientation of the greatest horizontal principal stress throughout the Pacific Northwest differs considerably from the direction of convergence between the Juan de Fuca and North American plates, the relationship between the stress field and forces acting along the subduction zone has been unclear. To address this relationship, a two-dimensional finite element model developed by Bird [1989] is used that incorporates critical aspects of continental deformation such as a stratified rheology and interaction between thermal and mechanical components of deformation. Boundary conditions are specified in terms of either velocity or shear traction, depending on whether the computed shear stress at the plate boundary is less than or exceeds, respectively, a prescribed limit. Shear-stress limits on the subduction and transform plate boundaries are independently varied to determine the relative effect of forces along these boundaries on intraplate deformation. Results from this study indicate that the shear stress limit of both subduction and transform boundaries is low, and that the intraplate stress field is attributed, in part, to the normal component of relative plate motion along the transform boundaries. However, the models also indicate that although the subduction zone fault is weak, a minimum shear strength ( ??? 10 MPa) for the fault is necessary to explain the observed stress field. The balance among forces along the tectonic boundaries of North America results in a surprising degree of variation in the present-day stress field.

  8. Global Source-Receptor Relationships for Mercury Deposition Under Present-Day and 2050 Emissions Scenarios

    PubMed Central

    Corbitt, Elizabeth S.; Jacob, Daniel J.; Holmes, Christopher D.; Streets, David G.; Sunderland, Elsie M.

    2011-01-01

    Global policies regulating anthropogenic mercury require an understanding of the relationship between emitted and deposited mercury on intercontinental scales. Here we examine source-receptor relationships for present-day conditions and for four 2050 IPCC scenarios encompassing a range of economic development and environmental regulation projections. We use the GEOS-Chem global model to track mercury from its point of emission through rapid cycling in surface ocean and land reservoirs to its accumulation in longer-lived ocean and soil pools. Deposited mercury has a local component (emitted HgII, lifetime of 3.7 days against deposition) and a global component (emitted Hg0, lifetime of 6 months against deposition). Fast recycling of deposited mercury through photoreduction of HgII and re-emission of Hg0 from surface reservoirs (ice, land, surface ocean) increases the effective lifetime of anthropogenic mercury to 9 months against loss to legacy reservoirs (soil pools and the subsurface ocean). This lifetime is still sufficiently short that source-receptor relationships have a strong hemispheric signature. Asian emissions are the largest source of anthropogenic deposition to all ocean basins, though there is also regional source influence from upwind continents. Current anthropogenic emissions account for only about one-third of mercury deposition to the global ocean with the remainder from natural and legacy sources. However, controls on anthropogenic emissions would have the added benefit of reducing the legacy mercury re-emitted to the atmosphere. Better understanding is needed of the timescales for transfer of mercury from active pools to stable geochemical reservoirs. PMID:22050654

  9. LAB - Transition between Fossil and Present-Day Flow-Related Seismic Anisotropy

    NASA Astrophysics Data System (ADS)

    Plomerova, J.; Babuska, V.; Vecsey, L.; Munzarova, H.

    2015-12-01

    Topography of the lithosphere-asthenosphere boundary (LAB) and structure of the continental lithosphere record geodynamic development of the outer parts of the Earth. Studying the architecture of plates and mapping the LAB discontinuity relief can help to answer questions how and when the plates assembled and to what extent they were later deformed. Differences in changes of physical properties across the "discontinuities" are significant, but sharpness of the transitions depends on optics we are using. Moreover, the nature of the boundary/transition remains uncertain. Fundamental difference in origin and orientation of seismic anisotropy in the mantle lithosphere and in the sub-lithospheric mantle has led us to develop an original approach of LAB modelling. We associate the LAB with a transition of fossil anisotropy in the rigid high-velocity lithosphere to present-day related anisotropy in the more viscous underlying asthenosphere. We present a global LAB model calculated from depth-dependences of azimuthal and radial anisotropy of surface waves (Plomerova et al., 2002) and a uniform model of the European LAB (Plomerova and Babuska, 2010), calculated from P-wave travel times collected during regional passive experiments. In the latter, the LAB is modelled according to an empirical residual-depth relation. The high velocity contrast across the LAB (δvP ~ 0.6 km/s) required by the empirical gradient cannot be accomplished by isotropic velocities of materials forming the upper mantle, while it can be explained by different orientations of the high-velocities above and below the LAB. Relief of the lower plate boundary can vary considerably on short lateral distances and it is exposed to erosion from asthenosphere. On the other hand, dipping fabrics of often sharply bounded lithospheric domains, created probably during a plate formation, indicate stability of such a fossilized structure, which alters only near the domain boundaries.

  10. A test of present-day plate geometries for northeast Asia and Japan

    NASA Technical Reports Server (NTRS)

    Demets, Charles

    1992-01-01

    Alternative geometries for the present-day configuration of plate boundaries in northeast Asia and Japan are tested using NUVEL-1 and 256 horizontal earthquake slip vectors from the Japan and northern Kuril trenches. Statistical analysis of the slip vectors is used to determine whether the North American, Eurasian, or Okhotsk plate overlies the trench. Along the northern Kuril trench, slip vectors are well-fit by the NUVEL-1 Pacific-North America Euler pole, but are poorly fit by the Pacific-Eurasia Euler pole. Results for the Japan trench are less conclusive, but suggest that much of Honshu and Hokkaido are also part of the North American plate. The simplest geometry consistent with the trench slip vectors is a geometry in which the North American plate extends south to 41 deg N, and possibly includes northern Honshu and southern Hokkaido. Although these results imply that the diffuse seismicity that connects the Lena River delta to Sakhalin Island and the eastern Sea of Japan records motion between Eurasia and North America, onshore geologic and seismic data define an additional belt of seismicity in Siberia that cannot be explained with this geometry. Assuming that these two seismic belts constitute evidence for an Okhotsk block, two published kinematic models for motion of the Okhotsk block are tested. The first model, which predicts motion of up to 15 mm/yr relative to North America, is rejected because Kuril and Japan trench slip vectors are fit more poorly than for the simpler geometry described above. The second model gives a good fit to the trench slip vectors, but only if Okhotsk-North America motion is slower than 5 mm/yr.

  11. Challenges in constraining anthropogenic aerosol effects on cloud radiative forcing using present-day spatiotemporal variability

    PubMed Central

    Ghan, Steven; Wang, Minghuai; Zhang, Shipeng; Ferrachat, Sylvaine; Gettelman, Andrew; Griesfeller, Jan; Kipling, Zak; Lohmann, Ulrike; Morrison, Hugh; Neubauer, David; Partridge, Daniel G.; Stier, Philip; Takemura, Toshihiko; Wang, Hailong; Zhang, Kai

    2016-01-01

    A large number of processes are involved in the chain from emissions of aerosol precursor gases and primary particles to impacts on cloud radiative forcing. Those processes are manifest in a number of relationships that can be expressed as factors dlnX/dlnY driving aerosol effects on cloud radiative forcing. These factors include the relationships between cloud condensation nuclei (CCN) concentration and emissions, droplet number and CCN concentration, cloud fraction and droplet number, cloud optical depth and droplet number, and cloud radiative forcing and cloud optical depth. The relationship between cloud optical depth and droplet number can be further decomposed into the sum of two terms involving the relationship of droplet effective radius and cloud liquid water path with droplet number. These relationships can be constrained using observations of recent spatial and temporal variability of these quantities. However, we are most interested in the radiative forcing since the preindustrial era. Because few relevant measurements are available from that era, relationships from recent variability have been assumed to be applicable to the preindustrial to present-day change. Our analysis of Aerosol Comparisons between Observations and Models (AeroCom) model simulations suggests that estimates of relationships from recent variability are poor constraints on relationships from anthropogenic change for some terms, with even the sign of some relationships differing in many regions. Proxies connecting recent spatial/temporal variability to anthropogenic change, or sustained measurements in regions where emissions have changed, are needed to constrain estimates of anthropogenic aerosol impacts on cloud radiative forcing. PMID:26921324

  12. The present-day stress field orientation in Italy: new release

    NASA Astrophysics Data System (ADS)

    Montone, P.; Mariucci, M. T.

    2015-12-01

    When contemporary stress field in a region is well-known and faults are identified, it is possible to determine which faults are favorably oriented and are more likely to slip in the future. Stress data are also an important input in integrated crustal modeling to get more reliable evaluations in many applicative researches. Then, the knowledge of the active stress field contributes to the seismotectonic zoning of a region. In Italy, although at large scale a first order stress field due to plate boundary forces controls the contemporary tectonics, some areas show changes in stress regime over small distances and/or with depth clearly linked to localized stress perturbations. Where information is lacking each prediction of stress patterns could significantly differ from the reality and any further evaluation would be weakly supported by data. Therefore we continuously collect the available stress indicators and here present an update of present-day stress orientations in Italy with the last 5 years data, relative to crustal earthquake focal mechanisms (0-40 km depth), borehole breakouts from deep wells and fault data. About 100 new quality-ranked entries complete the definition of the horizontal stress orientation and tectonic regime in some areas, and bring new information mainly in Po Plain and Calabria area, recently affected by important earthquake sequences. Now the global Italian dataset consists of ~800 data points, including ~580 of A-C quality, with an increase of 17% compared to the previous compilation (Montone et al., 2012). We use A-, B- and C-quality stress indicators for analyzing first-order stress patterns while we also consider D-quality data to define second-or third-order stress field, as observed in other studies in the world. In particular we discuss the simultaneous occurrence of different stress regimes and the complex interaction between first order stress field and local effects, and the influence of the inherited tectonic structures.

  13. Uncovering the genetic history of the present-day Greenlandic population.

    PubMed

    Moltke, Ida; Fumagalli, Matteo; Korneliussen, Thorfinn S; Crawford, Jacob E; Bjerregaard, Peter; Jørgensen, Marit E; Grarup, Niels; Gulløv, Hans Christian; Linneberg, Allan; Pedersen, Oluf; Hansen, Torben; Nielsen, Rasmus; Albrechtsen, Anders

    2015-01-01

    Because of past limitations in samples and genotyping technologies, important questions about the history of the present-day Greenlandic population remain unanswered. In an effort to answer these questions and in general investigate the genetic history of the Greenlandic population, we analyzed ∼200,000 SNPs from more than 10% of the adult Greenlandic population (n = 4,674). We found that recent gene flow from Europe has had a substantial impact on the population: more than 80% of the Greenlanders have some European ancestry (on average ∼25% of their genome). However, we also found that the amount of recent European gene flow varies across Greenland and is far smaller in the more historically isolated areas in the north and east and in the small villages in the south. Furthermore, we found that there is substantial population structure in the Inuit genetic component of the Greenlanders and that individuals from the east, west, and north can be distinguished from each other. Moreover, the genetic differences in the Inuit ancestry are consistent with a single colonization wave of the island from north to west to south to east. Although it has been speculated that there has been historical admixture between the Norse Vikings who lived in Greenland for a limited period ∼600-1,000 years ago and the Inuit, we found no evidence supporting this hypothesis. Similarly, we found no evidence supporting a previously hypothesized admixture event between the Inuit in East Greenland and the Dorset people, who lived in Greenland before the Inuit.

  14. Geochemical evaluation of present-day Tuul River sediments, Ulaanbaatar basin, Mongolia.

    PubMed

    Dalai, Banzragch; Ishiga, Hiroaki

    2013-03-01

    The Tuul River flows through the Ulaanbaatar basin of Mongolia and is the main source of water for the capital city, Ulaanbaatar. The Tuul catchment can be divided into three parts around Ulaanbaatar (upper, middle, and lower), according to the extent of urbanization. Sixteen surface water and groundwater samples were collected to evaluate present-day water quality and 34 stream sediment samples taken to examine their geochemical composition in relation to provenance and to assess the impact of urban activity on heavy metal accumulation. Groundwater quality in the upper and central water sources was adequate, but high concentrations of NO (3) (-) were found in the lower water source. Heavy metal concentrations in the sediments are evaluated by comparison with average upper continental crust (UCC) values, coupled with ecological risk assessment by reference to sediment quality guidelines (SQG). The results show average abundances of potentially toxic metals such as As, Pb, Zn, Cu, Ni, Cr, and V are higher in the middle part (within the city) than in the upper and lower parts. However, all three parts show depletion in some chalcophile and high field strength elements (Cu, Ni, Cr, Sr, Nb, Zr, Th, Sc) relative to UCC, indicating that the river sediments were derived from a highly felsic crustal source. The assessment using SQG shows As and Cr are present in levels that cause adverse aquatic biological effects. Although concentrations of Pb, Zn, Cu, and Ni are generally below their respective threshold effect levels, in the middle reaches, values increase and border on the probable effect level. This suggests significant anthropogenic contamination in the urban areas, increasing values above a naturally low regional background.

  15. Challenges in constraining anthropogenic aerosol effects on cloud radiative forcing using present-day spatiotemporal variability.

    PubMed

    Ghan, Steven; Wang, Minghuai; Zhang, Shipeng; Ferrachat, Sylvaine; Gettelman, Andrew; Griesfeller, Jan; Kipling, Zak; Lohmann, Ulrike; Morrison, Hugh; Neubauer, David; Partridge, Daniel G; Stier, Philip; Takemura, Toshihiko; Wang, Hailong; Zhang, Kai

    2016-05-24

    A large number of processes are involved in the chain from emissions of aerosol precursor gases and primary particles to impacts on cloud radiative forcing. Those processes are manifest in a number of relationships that can be expressed as factors dlnX/dlnY driving aerosol effects on cloud radiative forcing. These factors include the relationships between cloud condensation nuclei (CCN) concentration and emissions, droplet number and CCN concentration, cloud fraction and droplet number, cloud optical depth and droplet number, and cloud radiative forcing and cloud optical depth. The relationship between cloud optical depth and droplet number can be further decomposed into the sum of two terms involving the relationship of droplet effective radius and cloud liquid water path with droplet number. These relationships can be constrained using observations of recent spatial and temporal variability of these quantities. However, we are most interested in the radiative forcing since the preindustrial era. Because few relevant measurements are available from that era, relationships from recent variability have been assumed to be applicable to the preindustrial to present-day change. Our analysis of Aerosol Comparisons between Observations and Models (AeroCom) model simulations suggests that estimates of relationships from recent variability are poor constraints on relationships from anthropogenic change for some terms, with even the sign of some relationships differing in many regions. Proxies connecting recent spatial/temporal variability to anthropogenic change, or sustained measurements in regions where emissions have changed, are needed to constrain estimates of anthropogenic aerosol impacts on cloud radiative forcing. PMID:26921324

  16. Far-infrared and dust properties of present-day galaxies in the EAGLE simulations

    NASA Astrophysics Data System (ADS)

    Camps, Peter; Trayford, James W.; Baes, Maarten; Theuns, Tom; Schaller, Matthieu; Schaye, Joop

    2016-10-01

    The Evolution and Assembly of GaLaxies and their Environments (EAGLE) cosmological simulations reproduce the observed galaxy stellar mass function and many galaxy properties. In this work, we study the dust-related properties of present-day EAGLE galaxies through mock observations in the far-infrared and submm wavelength ranges obtained with the 3D dust radiative transfer code SKIRT. To prepare an EAGLE galaxy for radiative transfer processing, we derive a diffuse dust distribution from the gas particles and we re-sample the star-forming gas particles and the youngest star particles into star-forming regions that are assigned dedicated emission templates. We select a set of redshift-zero EAGLE galaxies that matches the K-band luminosity distribution of the galaxies in the Herschel Reference Survey (HRS), a volume-limited sample of about 300 normal galaxies in the Local Universe. We find overall agreement of the EAGLE dust scaling relations with those observed in the HRS, such as the dust-to-stellar mass ratio versus stellar mass and versus NUV-r colour relations. A discrepancy in the f250/f350 versus f350/f500 submm colour-colour relation implies that part of the simulated dust is insufficiently heated, likely because of limitations in our sub-grid model for star-forming regions. We also investigate the effect of adjusting the metal-to-dust ratio and the covering factor of the photodissociation regions surrounding the star-forming cores. We are able to constrain the important dust-related parameters in our method, informing the calculation of dust attenuation for EAGLE galaxies in the UV and optical domain.

  17. Liquid Water Lakes on Mars Under Present-Day Conditions: Sustainability and Effects on the Subsurface

    NASA Astrophysics Data System (ADS)

    Goldspiel, Jules M.

    2015-11-01

    Decades of Mars exploration have produced ample evidence that aqueous environments once existed on the surface. Much evidence supports groundwater emergence as the source of liquid water on Mars [1-4]. However, cases have also been made for rainfall [5] and snow pack melts [6].Whatever the mechanism by which liquid water is emplaced on the surface of Mars, whether from groundwater seeps, atmospheric precipitation, or some combination of sources, this water would have collected in local topographic lows, and at least temporarily, would have created a local surface water system with dynamic thermal and hydrologic properties. Understanding the physical details of such aqueous systems is important for interpreting the past and present surface environments of Mars. It is also important for evaluating potential habitable zones on or near the surface.In conjunction with analysis of surface and core samples, valuable insight into likely past aqueous sites on Mars can be gained through modeling their formation and evolution. Toward that end, we built a 1D numerical model to follow the evolution of small bodies of liquid water on the surface of Mars. In the model, liquid water at different temperatures is supplied to the surface at different rates while the system is subjected to diurnally and seasonally varying environmental conditions. We recently simulated cases of cold (275 K) and warm (350 K) water collecting in a small depression on the floor of a mid southern latitude impact crater. When inflows create an initial pool > 3 m deep and infiltration can be neglected, we find that the interior of the pool can remain liquid over a full Mars year under the present cold and dry climate as an ice cover slowly thickens [7]. Here we present new results for the thermal and hydrologic evolution of surface water and the associated subsurface region for present-day conditions when infiltration of surface water into the subsurface is considered.[1] Pieri (1980) Science 210.[2] Carr

  18. Present-Day 3D Velocity Field of Eastern North America Based on Continuous GPS Observations

    NASA Astrophysics Data System (ADS)

    Goudarzi, Mohammad Ali; Cocard, Marc; Santerre, Rock

    2016-07-01

    The Saint Lawrence River valley in eastern Canada was studied using observations of continuously operating GPS (CGPS) stations. The area is one of the most seismically active regions in eastern North America characterized by many earthquakes, which is also subject to an ongoing glacial isostatic adjustment. We present the current three-dimensional velocity field of eastern North America obtained from more than 14 years (9 years on average) of data at 112 CGPS stations. Bernese GNSS and GITSA software were used for CGPS data processing and position time series analysis, respectively. The results show the counterclockwise rotation of the North American plate in the No-Net-Rotation model with the average of 16.8 ± 0.7 mm/year constrained to ITRF 2008. We also present an ongoing uplift model for the study region based on the present-day CGPS observations. The model shows uplift all over eastern Canada with the maximum rate of 13.7 ± 1.2 mm/year and subsidence to the south mainly over northern USA with a typical rate of -1 to -2 mm/year and the minimum value of -2.7 ± 1.4 mm/year. We compared our model with the rate of radial displacements from the ICE-5G model. Both models agree within 0.02 mm/year at the best stations; however, our model shows a systematic spatial tilt compared to ICE-5G. The misfits between two models amount to the maximum relative subsidence of -6.1 ± 1.1 mm/year to the east and maximum relative uplift of 5.9 ± 2.7 mm/year to the west. The intraplate horizontal velocities are radially outward from the centers of maximum uplift and are inward to the centers of maximum subsidence with the typical velocity of 1-1.6 ± 0.4 mm/year that is in agreement with the ICE-5G model to the first order.

  19. Importance of Past Human and Natural Disturbance in Present-Day Net Ecosystem Productivity

    NASA Astrophysics Data System (ADS)

    Felzer, B. S.; Phelps, P.

    2014-12-01

    Gridded datasets of Net Ecosystem Exchange derived from eddy covariance and remote sensing measurements provide a means of validating Net Ecosystem Productivity (NEP, opposite of NEE) from terrestrial ecosystem models. While most forested regions in the U.S. are observed to be moderate to strong carbon sinks, models not including human or natural disturbances will tend to be more carbon neutral, which is expected of mature ecosystems. We have developed the Terrestrial Ecosystems Model Hydro version (TEM-Hydro) to include both human and natural disturbances to compare against gridded NEP datasets. Human disturbances are based on the Hurtt et al. (2006) land use transition dataset and include transient agricultural (crops and pasture) conversion and abandonment and timber harvest. We include natural disturbances of storms and fires based on stochastic return intervals. Tropical storms and hurricane return intervals are based on Zheng et al. (2009) and occur only along the U.S. Atlantic and Gulf coasts. Fire return intervals are based on LANDFIRE Rapid Assessment Vegetation Models and vegetation types from the Hurtt dataset. We are running three experiments with TEM-Hydro from 1700-2011 for the conterminous U.S.: potential vegetation (POT), human disturbance only (agriculture and timber harvest, LULC), and human plus natural disturbance (agriculture, timber harvest, storms, and fire, DISTURB). The goal is to compare our NEP values to those obtained by FLUXNET-MTE (Jung et al. 2009) from 1982-2008 and ECMOD (Xiao et al., 2008) from 2000-2006 for different plant functional types (PFTs) within the conterminous U.S. Preliminary results show that, for the entire U.S., potential vegetation yields an NEP of 10.8 gCm-2yr-1 vs 128.1 gCm-2yr-1 for LULC and 89.8 gCm-2yr-1 for DISTURB from 1982-2008. The effect of regrowth following agricultural and timber harvest disturbance therefore contributes substantially to the present-day carbon sink, while stochastic storms and fires

  20. Statistical dynamical downscaling of present day and future precipitation regimes in southern Vietnam

    NASA Astrophysics Data System (ADS)

    Schubert, David; Reyers, Mark; Pinto, Joaquim; Fink, Andreas; Massmeyer, Klaus

    2016-04-01

    Southeast Asia has been identified as one of the hot-spots of climate change. While the projected changes in annual precipitation are comparatively small, there is a clear tendency towards more rainfall in the dry season and an increase in extreme precipitation events. In this study, a statistical dynamical downscaling (SDD) approach is applied to obtain higher resolution and more robust regional climate change projections for tropical Southeast Asia with focus on Vietnam. First, a recent climate (RC) simulation with the regional climate model COSMO-CLM with a spatial resolution of ~50 km driven by ERA-Interim (1979-2008) is performed for the tropical region of Southeast Asia. For the SDD, six weather types (WTs) are selected for Vietnam during the wet season (April - October) using a k-means cluster analysis of daily zonal wind component in 850 hPa and 200 hPa from the RC run. For each calculated weather type, simulated representatives are selected from the RC run and are then further dynamically downscaled to a resolution of 0.0625° (7 km). By using historical WT frequencies, the simulated representatives are recombined to a high resolution rainfall climatology for the recent climate. It is shown that the SDD is generally able to capture the present day climatology and that the employment of the higher resolved simulated representatives enhances the performance of the SDD. However, an overestimation of rainfall at higher altitudes is found. To obtain future climate projections, an ensemble of eight CMIP5 model members are selected to study precipitation changes. For these projections, WT frequencies of future scenarios under two representative Concentration Pathways (RCP4.5 and RCP8.5) are taken into account for the mid-term scenario (2046-2065) and the long-term scenario (2081-2100). The strongest precipitation changes are found for the RCP8.5 scenario. Most of the models indicate a generally increase in precipitation amount in the wet period over Southeast

  1. Estimating hypothetical present-day insured losses for past intense hurricanes in the French Antilles

    NASA Astrophysics Data System (ADS)

    Thornton, James; Desarthe, Jérémy; Naulin, Jean-Philippe; Garnier, Emmanuel; Liu, Ye; Moncoulon, David

    2015-04-01

    On the islands of the French Antilles, the period for which systematic meteorological measurements and historic event loss data are available is short relative to the recurrence intervals of very intense, damaging hurricanes. Additionally, the value of property at risk changes through time. As such, the recent past can only provide limited insight into potential losses from extreme storms in coming years. Here we present some research that seeks to overcome, as far as is possible, the limitations of record length in assessing the possible impacts of near-future hurricanes on insured properties. First, using the archives of the French overseas departments (which included administrative and weather reports, inventories of damage to houses, crops and trees, as well as some meteorological observations after 1950) we reconstructed the spatial patterns of hazard intensity associated with three historical events. They are: i) the 1928 Hurricane (Guadeloupe), ii) Hurricane Betsy (1956, Guadeloupe) and iii) Hurricane David (1979, Martinique). These events were selected because all were damaging, and the information available on each is rich. Then, using a recently developed catastrophe model for hurricanes affecting Guadeloupe, Martinique, Saint-Barthélemy and Saint-Martin, we simulated the hypothetical losses to insured properties that the reconstructed events might cause if they were to reoccur today. The model simulated damage due to wind, rainfall-induced flooding and storm surge flooding. These 'what if' scenarios provided an initial indication of the potential present-day exposure of the insurance industry to intense hurricanes. However, we acknowledge that historical events are unlikely to repeat exactly. We therefore extended the study by producing a stochastic event catalogue containing a large number of synthetic but plausible hurricane events. Instrumental data were used as a basis for event generation, but importantly the statistical methods we applied permit

  2. Influence of ocean tide dynamics on the climate system from the Cretaceous to present day

    NASA Astrophysics Data System (ADS)

    Weber, Tobias; Thomas, Maik

    2016-04-01

    Global numerical ocean models used for paleo-climate reconstructions generally only consider the ocean's general circulation, but neglect tidal dynamics. However, it has been demonstrated that tidally induced friction at the ocean bottom alters the mean ocean circulation and energy fluxes on timescales larger than one tidal period and up to climate timescales. Thereby the mean ocean circulation and temperature advection is altered and can thus affect climate. We simultaneously modeled the ocean's general circulation and tidal dynamics for five time-slices from the Cretaceous to present day: the Albian (ca. 110 million years ago, Ma), the Cenomanian-Turonian Boundary (ca. 93 Ma, CTB), the early Eocene (ca. 55 Ma), the early Pliocene (ca. 3.5 Ma), and a pre-industrial period (ca. 1850 AD). These simulations show that the tectonic evolution of ocean basins changes the resonance conditions in the paleo-oceans over time and thus the position of amphydromic systems and the amplitudes of partial tides. Largest amplitudes of the M2 partial tide are obtained during the early Eocene when they are in the global mean by 150% larger than in the CTB, when amplitudes are smallest. The evolution of the tidal system leads to an individual interaction between tidal dynamics and the ocean general circulation for all time-slices. In the Albian a reduction of horizontal velocities of up to 50% is simulated in the deep Indo-Pacific Throughflow (IPT) below 1000m depth. This reduction is the product of tidal residual mean currents induced by tidal waves propagating from the Pacific Ocean into the Indian Ocean that oppose the prevailing eastward thermohaline currents. In all other time-slices mainly an increase in horizontal transports is simulated. In the CTB both tidal residual mean currents (less than 0.2cm/s in most of the ocean) and the general ocean circulation (less than 0.5cm/s) are small, thus leading to a tidally induced increase by 50% in horizontal velocities in almost half of

  3. Potential autotrophic metabolisms in ultra-basic reducing springs associated with present-day continental serpentinization

    NASA Astrophysics Data System (ADS)

    Morrill, P. L.; Miles, S.; Kohl, L.; Kavanagh, H.; Ziegler, S. E.; Brazelton, W. J.; Schrenk, M. O.

    2013-12-01

    Ultra-basic reducing springs at continental sites of serpentinization act as windows into the biogeochemistry of this subsurface exothermic environment rich in H2 and CH4 gases. Biogeochemical carbon transformations in these systems are of interest because serpentinization creates conditions that are amenable to abiotic and biotic reduction of carbon. However, little is known about the metabolic capabilities of the microorganisms that live in this environment. To determine the potential for autotrophic metabolisms, bicarbonate and CO substrate addition microcosm experiments were performed using water and sediment from an ultra-basic reducing spring in the Tablelands, Newfoundland, Canada, a site of present-day continental serpentinization. CO was consistently observed to be utilized in the Live but not the Killed controlled replicates amended with 10% 13C labelled CO and non-labelled (natural C isotope abundance) CO. In the Live CO microcosms with natural C isotope abundance, the residual CO became enriched in 13C (~10 ‰) consistent with a decrease in the fraction of CO remaining. In the Killed CO controlled replicates with natural C isotope abundance the CO showed little 13C enrichment (~1.3 ‰). The data from the Live CO microcosms were well described by a Rayleigh isotopic distillation model, yielding an isotopic enrichment factor for microbial CO uptake of 15.7 ×0.5 ‰ n=2. These data suggest that there was microbial CO utilization in these experiments. The sediment and water from the 13C-labelled and non-labelled, Live and Killed microcosms were extracted for phospholipid fatty acids (PLFAs) to determine changes in community composition between treatments as well as to determine the microbial uptake of CO. The difference in community composition between the Live and Killed microcosms was not readily resolvable based on PLFA distributions. Additionally, the microbial uptake of 13CO had minimal to no affect on the δ13C of the cellular biomarkers, with the

  4. Present-Day Seasonal Gully Activity in a South Polar Pit (Sisyphi Cavi) on Mars

    NASA Astrophysics Data System (ADS)

    Raack, Jan; Reiss, Dennis; Appéré, Thomas; Vincendon, Mathieu; Ruesch, Ottaviano; Hiesinger, Harald

    2014-05-01

    Seasonal activity of gullies under current climatic conditions on Mars was observed by [1-7]. Dundas et al. [2] reviewed the present-day activity of classical gullies (including the gully presented in this work), dune gullies, and other mass wasting processes in the southern hemisphere on Mars. Recent polar gullies in Sisyphi Cavi were also analyzed by [8], who estimated ages of about 20 ka to 20 Ma for the gullies. In this study we focus on a single gully in Sisyphi Cavi, located in the south polar region at 1.44° E and 68.54° S. The gully occurs on the gullied equator-facing slope of an isolated polar pit within an infilled impact crater. Multi-temporal high-resolution image data analyses show new deposits at the terminus of the gully channel and on the gully apron within spring (after solar longitudes of 236°) of martian years (MY) 29 and 31. In MY 29 deposition of material shortens the channel by about 40 m; in MY 31 a new deposit at the western flank of the gully apron with approximately 300-600 m3 of material is visible [3]. Our morphological investigations show that the identified new deposits were formed by dark flows through the entire gully deposited on top of the apron between LS ~218° and ~226°. Thermal data show a temperature increase between solar longitudes (LS) ~218° and ~226°. Near-infrared spectral data show relatively constant band strengths of CO2 ice and H2O ice in this time range. After the formation of the dark flows (after LS ~226°), temperatures increase rapidly from ~180 K to >~270 K at LS ~250°. At this time, spectral data indicate that all volatiles on the surface sublimated. However, an earlier beginning of sublimation when the dark flows were observed (between LS ~218° and ~226°) is likely, due to the fact that the instruments can only show the last phase of sublimation (decrease of volatile band strengths) [3]. Spectral modeling shows that from winter to mid-spring, the surface of the studied area is covered by CO2 slab

  5. HLA class II genotypes in Mexican Mestizos with familial and nonfamilial multiple sclerosis.

    PubMed

    Alvarado-de la Barrera, C; Zúñiga-Ramos, J; Ruíz-Morales, J A; Estañol, B; Granados, J; Llorente, L

    2000-12-26

    Predisposition to MS is associated with the HLA-DR2 antigen in white patients. The authors investigated the genetic factors behind the increasing frequency of MS in the Mexican population. HLA-DR and DQ were analyzed in 17 patients with MS, 15 of their first-degree relatives, and 99 healthy ethnically matched controls. DR2 or DR3 was found in 15 of 17 patients. In controls, both alleles had frequencies less than 0.05. MS in Mexican patients was associated with HLA-DR2 and DR3.

  6. Association of vWA and TPOX Polymorphisms with Venous Thrombosis in Mexican Mestizos

    PubMed Central

    Meraz-Ríos, Marco Antonio; Majluf-Cruz, Abraham; Santana, Carla; Noris, Gino; Camacho-Mejorado, Rafael; Acosta-Saavedra, Leonor C.; Calderón-Aranda, Emma S.; Hernández-Juárez, Jesús; Magaña, Jonathan J.; Gómez, Rocío

    2014-01-01

    Objective. Venous thromboembolism (VTE) is a multifactorial disorder and, worldwide, the most important cause of morbidity and mortality. Genetic factors play a critical role in its aetiology. Microsatellites are the most important source of human genetic variation having more phenotypic effect than many single nucleotide polymorphisms. Hence, we evaluate a possible relationship between VTE and the genetic variants in von Willebrand factor, human alpha fibrinogen, and human thyroid peroxidase microsatellites to identify possible diagnostic markers. Methods. Genotypes were obtained from 177 patients with VTE and 531 nonrelated individuals using validated genotyping methods. The allelic frequencies were compared; Bayesian methods were used to correct population stratification to avoid spurious associations. Results. The vWA-18, TPOX-9, and TPOX-12 alleles were significantly associated with VTE. Moreover, subjects bearing the combination vWA-18/TPOX-12 loci exhibited doubled risk for VTE (95% CI = 1.02–3.64), whereas the combination vWA-18/TPOX-9 showed an OR = 10 (95% CI = 4.93–21.49). Conclusions. The vWA and TPOX microsatellites are good candidate biomarkers in venous thromboembolism diseases and could help to elucidate their origins. Additionally, these polymorphisms could become useful markers for genetic studies of VTE in the Mexican population; however, further studies should be done owing that this data only show preliminary evidence. PMID:25250329

  7. Pollution of the Black Sea coastal waters: Sources, present-day level, annual variability

    SciTech Connect

    Fashchuk, D.Ya.; Shaporenko, S.I.

    1995-05-01

    Results of regular (for the last 10 years) observations at marine and coastal hydrometeorological posts are analyzed. These are observations of volumes and concentrations of pollutants entering the sea with the flow of the Danube and Dnieper rivers and wastewaters of coastal industrial enterprises, as a result of oil spills caused by ship accidents, pipeline damage, and sea shipping. An integral criterion used to estimate the overall specific anthropogenic load of pollutants in the coastal zone is calculated. The pollutants were compared with regard to their overall specific load, taking into account the percentage of each of them. A water pollution index is calculated for 19 regions of the sea; water quality is evaluated for three types of pollutants and oxygen content. Pollution structure is revealed, physical and dynamic causes of its changes are investigated.

  8. Sedimentary Mounds on Mars: Tracing Present-day Formation Processes into the Past

    NASA Technical Reports Server (NTRS)

    Niles, P. B.; Michalski, J.; Edwards, C. S.

    2014-01-01

    High resolution photography and spectroscopy of the martian surface (MOC, HiRISE) from orbit has revolutionized our view of Mars with one and revealed spectacular views of finely layered sedimentary materials throughout the globe [1]. Some of these sedimentary deposits are 'mound' shaped and lie inside of craters (Fig 1). Crater mound deposits are found throughout the equatorial region, as well as ice-rich deposits found in craters in the north and south polar region [2-4]. Despite their wide geographical extent and varying volatile content, the 'mound' deposits have a large number of geomorphic and structural similarities that suggest they formed via equivalent processes. Thus, modern depositional processes of ice and dust can serve as an invaluable analog for interpreting the genesis of ancient sedimentary mound deposits.

  9. Present-Day Vegetation Helps Quantifying Past Land Cover in Selected Regions of the Czech Republic

    PubMed Central

    Abraham, Vojtěch; Oušková, Veronika; Kuneš, Petr

    2014-01-01

    The REVEALS model is a tool for recalculating pollen data into vegetation abundances on a regional scale. We explored the general effect of selected parameters by performing simulations and ascertained the best model setting for the Czech Republic using the shallowest samples from 120 fossil sites and data on actual regional vegetation (60 km radius). Vegetation proportions of 17 taxa were obtained by combining the CORINE Land Cover map with forest inventories, agricultural statistics and habitat mapping data. Our simulation shows that changing the site radius for all taxa substantially affects REVEALS estimates of taxa with heavy or light pollen grains. Decreasing the site radius has a similar effect as increasing the wind speed parameter. However, adjusting the site radius to 1 m for local taxa only (even taxa with light pollen) yields lower, more correct estimates despite their high pollen signal. Increasing the background radius does not affect the estimates significantly. Our comparison of estimates with actual vegetation in seven regions shows that the most accurate relative pollen productivity estimates (PPEs) come from Central Europe and Southern Sweden. The initial simulation and pollen data yielded unrealistic estimates for Abies under the default setting of the wind speed parameter (3 m/s). We therefore propose the setting of 4 m/s, which corresponds to the spring average in most regions of the Czech Republic studied. Ad hoc adjustment of PPEs with this setting improves the match 3–4-fold. We consider these values (apart from four exceptions) to be appropriate, because they are within the ranges of standard errors, so they are related to original PPEs. Setting a 1 m radius for local taxa (Alnus, Salix, Poaceae) significantly improves the match between estimates and actual vegetation. However, further adjustments to PPEs exceed the ranges of original values, so their relevance is uncertain. PMID:24936973

  10. Present-day vegetation helps quantifying past land cover in selected regions of the Czech Republic.

    PubMed

    Abraham, Vojtěch; Oušková, Veronika; Kuneš, Petr

    2014-01-01

    The REVEALS model is a tool for recalculating pollen data into vegetation abundances on a regional scale. We explored the general effect of selected parameters by performing simulations and ascertained the best model setting for the Czech Republic using the shallowest samples from 120 fossil sites and data on actual regional vegetation (60 km radius). Vegetation proportions of 17 taxa were obtained by combining the CORINE Land Cover map with forest inventories, agricultural statistics and habitat mapping data. Our simulation shows that changing the site radius for all taxa substantially affects REVEALS estimates of taxa with heavy or light pollen grains. Decreasing the site radius has a similar effect as increasing the wind speed parameter. However, adjusting the site radius to 1 m for local taxa only (even taxa with light pollen) yields lower, more correct estimates despite their high pollen signal. Increasing the background radius does not affect the estimates significantly. Our comparison of estimates with actual vegetation in seven regions shows that the most accurate relative pollen productivity estimates (PPEs) come from Central Europe and Southern Sweden. The initial simulation and pollen data yielded unrealistic estimates for Abies under the default setting of the wind speed parameter (3 m/s). We therefore propose the setting of 4 m/s, which corresponds to the spring average in most regions of the Czech Republic studied. Ad hoc adjustment of PPEs with this setting improves the match 3-4-fold. We consider these values (apart from four exceptions) to be appropriate, because they are within the ranges of standard errors, so they are related to original PPEs. Setting a 1 m radius for local taxa (Alnus, Salix, Poaceae) significantly improves the match between estimates and actual vegetation. However, further adjustments to PPEs exceed the ranges of original values, so their relevance is uncertain. PMID:24936973

  11. Monitoring present day climatic conditions in tropical caves using an Environmental Data Acquisition System (EDAS)

    NASA Astrophysics Data System (ADS)

    Sondag, Francis; van Ruymbeke, Michel; Soubiès, François; Santos, Roberto; Somerhausen, André; Seidel, Alexandre; Boggiani, Paulo

    2003-03-01

    This paper presents data from automatic stations which have been installed for monitoring climatic parameters in caves in two areas of Brazil. These devices, initially developed at the Royal Observatory of Belgium to monitor environmental parameters in geophysical observatories, were adapted in our study to operate under tropical cave conditions and to measure temperature, atmospheric pressure and drip rate of stalactites. Similar devices were installed at the surface near to the caves to measure air temperature, atmospheric pressure and rainfall. The results reveal that the drip rate at the tip of stalactites is related to the effective rainfall (water excess). The stable drip regime observed during the dry season seems to be reproducible from one year to the other and could be related to the infiltration of water which has a long residence time in the aquifer. Regular pressure oscillations, with amplitude ranging between 1 and 2 mb, are observed in both of the monitored caves. Spectral analysis of the data suggests that these oscillations are linked to the diurnal and semi-diurnal solar tides (S1 and S2). In one cave, very small temperature variations (0.02-0.05 °C) are also observed with a similar diurnal and semi-diurnal pattern, and we argue that the generating process of the thermal components of the S1 and S2 frequencies is a mixture of thermal convection produced by the surface meteorological variations and of an adiabatic induction of the S2 atmospheric pressure modulation. A very large annual thermal amplitude (13 °C) is observed in the other cave; this is a great motivation to study the stable isotope geochemistry of its speleothems as they probably have recorded past temperature fluctuations linked to paleoclimate variations in this area of south-western Brazil.

  12. Body wave travel times and amplitudes for present-day seismic model of Mars

    NASA Astrophysics Data System (ADS)

    Raevskiy, Sergey; Gudkova, Tamara

    Martian seismicity (Knapmeyer et al., 2006) seismic moment was assumed to be 10 (13) - 10 (16) Nm. The problem if it is possible to reveal differences between the models with different water content in mantle minerals and the attenuating properties of the mantle by comparing the travel times of body waves and their amplitudes is considered. This work was supported by Grant No. 12-02-00378 from the Russian Fund for Fundamental Research.

  13. Lyman Alpha-emitting Galaxies at z = 2.1: Characterizing the Progenitors of Typical Present-day Galaxies

    NASA Astrophysics Data System (ADS)

    Gawiser, Eric J.; Guaita, L.; Padilla, N.; Francke, H.; Bond, N. A.; Gronwall, C.; Ciardullo, R.; Sinawa, S.; Feldmeier, J. J.; MUSYC Collaboration

    2010-01-01

    We discovered a sample of 261 Lyman alpha emitting (LAE) galaxies at z=2.1 in an ultra-deep 3727A narrow-band MUSYC image of the Extended Chandra Deep Field-South. LAEs were selected to have rest-frame equivalent widths >20A and emission line fluxes >3.7x10-17 ergs/cm2/s, corresponding to L_Lya>1.2x1042 ergs/s. 3% of the original candidates were detected in X-rays by Chandra, and 7% were detected in the rest-frame far-UV by GALEX; these objects were eliminated to minimize contamination by AGN and low-redshift galaxies. Our sample has median rest-frame EW=40A, and only a few galaxies have rest-frame EW bigger than 200A. Our results show that the luminosity function of LAEs at z=2.1 is consistent with that of LAEs at z=3.1 but with number density a factor of 1.8+-0.3 higher. We used the rest frame UV luminosity to estimate a median star formation rate of 4 Msun/yr. Clustering analysis reveals that LAEs at z=2.1 have r0=3+-0.5 Mpc, corresponding to b=1.0+-0.2, the lowest clustering bias of any high-redshift galaxy population. This implies that z=2.1 LAEs reside in dark matter halos with masses 1010 Msun, which are the lowest-mass halos yet probed at this redshift. We used the Sheth-Tormen conditional mass function to study the descendants of these LAEs and found that their typical present-day descendants are local galaxies with sub-L* and L* luminosities, like the Milky Way. We gratefully acknowledge grant support for this research from NSF, DOE, and NASA.

  14. Present-day crustal deformation along the Magallanes-Fagnano Fault System in Tierra del Fuego from repeated GPS observations

    NASA Astrophysics Data System (ADS)

    Mendoza, L.; Perdomo, R.; Hormaechea, J. L.; Del Cogliano, D.; Fritsche, M.; Richter, A.; Dietrich, R.

    2011-03-01

    The present-day deformation of the earth crust in the Argentine part of Tierra del Fuego main island (southernmost South America) is here investigated based on repeated geodetic GPS observations. The island is traversed by the active transform boundary between the South American and Scotia tectonic plates, represented by the Magallanes-Fagnano fault system. Since 1993 a regional network comprising to date 29 GPS sites has been observed almost every year. The complete set of accumulated observations was processed using the Bernese GPS software and state-of-the-art processing strategies and models. The utilization of homogeneous GPS products resulting from a reprocessing of the global IGS network warrants a stable realization of a global reference frame. For each GPS site 3-D positions and linear velocities with error estimates were obtained. A strain analysis of the horizontal velocity components revealed the zones of major deformation activity. A 30-km-wide deformation belt centred on the main trace of the fault system was identified. This belt is bordered to the north (South America) and south (Scotia) by geodynamically stable zones, which move horizontally with a relative average velocity of 4.4 ± 0.6 (east) and -0.3 ± 0.4 (north) mm a-1. Within the deformation belt a maximum strain rate in the order of 0.25 μstrain per year has been detected. A pronounced change in the deformation style from transtension (east) to transpression (west) is observed. The area of predominating shortening of the crust coincides with a local rotation minimum and relative uplift. Throughout the period covered by the GPS observations the displacements and deformations occurred to be linear with time.

  15. Mantle-circulation models with sequential data assimilation: inferring present-day mantle structure from plate-motion histories.

    PubMed

    Bunge, Hans-Peter; Richards, M A; Baumgardner, J R

    2002-11-15

    limited in age to the Cretaceous. This result implies that sequential assimilation of past plate-motion models is ineffective in studying the temporal evolution of core-mantle-boundary heterogeneity, and that a method for extrapolating present-day information backwards in time is required. For short time periods (of the order of perhaps a few tens of Myr) such a method exists in the form of crude 'backward' convection calculations. For longer time periods (of the order of a mantle overturn), a rigorous approach to extrapolating information back in time exists in the form of iterative nonlinear optimization methods that carry assimilated information into the past through the use of an adjoint mantle convection model. PMID:12460480

  16. Mantle-circulation models with sequential data assimilation: inferring present-day mantle structure from plate-motion histories.

    PubMed

    Bunge, Hans-Peter; Richards, M A; Baumgardner, J R

    2002-11-15

    limited in age to the Cretaceous. This result implies that sequential assimilation of past plate-motion models is ineffective in studying the temporal evolution of core-mantle-boundary heterogeneity, and that a method for extrapolating present-day information backwards in time is required. For short time periods (of the order of perhaps a few tens of Myr) such a method exists in the form of crude 'backward' convection calculations. For longer time periods (of the order of a mantle overturn), a rigorous approach to extrapolating information back in time exists in the form of iterative nonlinear optimization methods that carry assimilated information into the past through the use of an adjoint mantle convection model.

  17. Genetic structure of Flores island (Azores, Portugal) in the 19th century and in the present day: evidence from surname analysis.

    PubMed

    Santos, Cristina; Abade, Augusto; Cantons, Jordi; Mayer, Francine M; Aluja, M Pilar; Lima, Manuela

    2005-06-01

    The island of Flores is the most westerly of the Azores archipelago (Portugal). Despite its marked geographic isolation and reduced population size, biodemographic and genetic studies conducted so far do not support the idea that its population constitutes a genetic isolate. In this study we conducted a surname analysis of the Flores population for two time periods: the second half of the 19th century and the present day. Our main purposes were (1) to biodemographically and genetically characterize the island, taking into account the strong reduction in population observed from the middle of the 19th century to the present day; and (2) to analyze the influence that the effective population size and geographic distance have on the genetic structure of populations. For both periods analyzed, all indicators of diversity revealed a high level of surname diversity. Our results are in accordance with the diversity estimates obtained from both monoparental genetic markers located in the Y chromosome and frequencies of mtDNA haplogroups. Contrary to what could be expected, considering the strong reduction of population in the last 150 years, we observed that diversity was maintained and that microdifferentiation decreased. Both observations support a higher openness of parishes as a consequence of the increase in communication routes. From the first to the second period analyzed, a change in surname composition is evident, although the more frequent surnames in Flores are almost the same for both periods and some of them are reported to be surnames present in the first settlers of Flores. This result testifies to the impact of founders on the present-day gene pool of Flores island and allows us to infer that the genetic characterization of the present-day population of Flores could provide reliable information about the history of the peopling of the Azores.

  18. Genetic structure of Flores island (Azores, Portugal) in the 19th century and in the present day: evidence from surname analysis.

    PubMed

    Santos, Cristina; Abade, Augusto; Cantons, Jordi; Mayer, Francine M; Aluja, M Pilar; Lima, Manuela

    2005-06-01

    The island of Flores is the most westerly of the Azores archipelago (Portugal). Despite its marked geographic isolation and reduced population size, biodemographic and genetic studies conducted so far do not support the idea that its population constitutes a genetic isolate. In this study we conducted a surname analysis of the Flores population for two time periods: the second half of the 19th century and the present day. Our main purposes were (1) to biodemographically and genetically characterize the island, taking into account the strong reduction in population observed from the middle of the 19th century to the present day; and (2) to analyze the influence that the effective population size and geographic distance have on the genetic structure of populations. For both periods analyzed, all indicators of diversity revealed a high level of surname diversity. Our results are in accordance with the diversity estimates obtained from both monoparental genetic markers located in the Y chromosome and frequencies of mtDNA haplogroups. Contrary to what could be expected, considering the strong reduction of population in the last 150 years, we observed that diversity was maintained and that microdifferentiation decreased. Both observations support a higher openness of parishes as a consequence of the increase in communication routes. From the first to the second period analyzed, a change in surname composition is evident, although the more frequent surnames in Flores are almost the same for both periods and some of them are reported to be surnames present in the first settlers of Flores. This result testifies to the impact of founders on the present-day gene pool of Flores island and allows us to infer that the genetic characterization of the present-day population of Flores could provide reliable information about the history of the peopling of the Azores. PMID:16392635

  19. Simulating the Greenland ice sheet under present-day and palaeo constraints including a new discharge parameterization

    NASA Astrophysics Data System (ADS)

    Calov, R.; Robinson, A.; Perrette, M.; Ganopolski, A.

    2015-02-01

    In this paper, we propose a new sub-grid scale parameterization for the ice discharge into the ocean through outlet glaciers and inspect the role of different observational and palaeo constraints for the choice of an optimal set of model parameters. This parameterization was introduced into the polythermal ice-sheet model SICOPOLIS, which is coupled to the regional climate model of intermediate complexity REMBO. Using the coupled model, we performed large ensemble simulations over the last two glacial cycles by varying two major parameters: a melt parameter in the surface melt scheme of REMBO and a discharge scaling parameter in our parameterization of ice discharge. Our empirical constraints are the present-day Greenland ice sheet surface elevation, the surface mass balance partition (ratio between total ice discharge and total precipitation) and the Eemian interglacial elevation drop relative to present day in the vicinity of the NEEM ice core. We show that the ice discharge parameterization enables us to simulate both the correct ice-sheet shape and mass balance partition at the same time without explicitly resolving the Greenland outlet glaciers. For model verification, we compare the simulated total and sectoral ice discharge with other estimates. For the model versions that are consistent with the range of observational and palaeo constraints, our simulated Greenland ice sheet contribution to Eemian sea-level rise relative to present-day amounts to 1.4 m on average (in the range of 0.6 and 2.5 m).

  20. Using present-day observations to detect when anthropogenic change forces surface ocean carbonate chemistry outside preindustrial bounds

    NASA Astrophysics Data System (ADS)

    Sutton, Adrienne J.; Sabine, Christopher L.; Feely, Richard A.; Cai, Wei-Jun; Cronin, Meghan F.; McPhaden, Michael J.; Morell, Julio M.; Newton, Jan A.; Noh, Jae-Hoon; Ólafsdóttir, Sólveig R.; Salisbury, Joseph E.; Send, Uwe; Vandemark, Douglas C.; Weller, Robert A.

    2016-09-01

    One of the major challenges to assessing the impact of ocean acidification on marine life is detecting and interpreting long-term change in the context of natural variability. This study addresses this need through a global synthesis of monthly pH and aragonite saturation state (Ωarag) climatologies for 12 open ocean, coastal, and coral reef locations using 3-hourly moored observations of surface seawater partial pressure of CO2 and pH collected together since as early as 2010. Mooring observations suggest open ocean subtropical and subarctic sites experience present-day surface pH and Ωarag conditions outside the bounds of preindustrial variability throughout most, if not all, of the year. In general, coastal mooring sites experience more natural variability and thus, more overlap with preindustrial conditions; however, present-day Ωarag conditions surpass biologically relevant thresholds associated with ocean acidification impacts on Mytilus californianus (Ωarag < 1.8) and Crassostrea gigas (Ωarag < 2.0) larvae in the California Current Ecosystem (CCE) and Mya arenaria larvae in the Gulf of Maine (Ωarag < 1.6). At the most variable mooring locations in coastal systems of the CCE, subseasonal conditions approached Ωarag = 1. Global and regional models and data syntheses of ship-based observations tended to underestimate seasonal variability compared to mooring observations. Efforts such as this to characterize all patterns of pH and Ωarag variability and change at key locations are fundamental to assessing present-day biological impacts of ocean acidification, further improving experimental design to interrogate organism response under real-world conditions, and improving predictive models and vulnerability assessments seeking to quantify the broader impacts of ocean acidification.

  1. The present-day strain partitioning of the Western Alps and its relationships with the crustal scale geometry

    NASA Astrophysics Data System (ADS)

    Schwartz, S.; Lardeaux, J. M.; Tricart, P.; Paul, A.; Béthoux, N.; Masson, F.

    2003-04-01

    In the orogenic belt, the combination of the geological data (tectonic, petrologic and kinematic analysis) with the geophysical imagery of the crust (regional seismicity, local earthquake tomography and gravimetry) allows to obtain crustal scale models coherent with the present-day deformation. In this way, the recent pluridisciplinary studies performed in the framework of " Geo-France 3D Alpes " show an important syn-convergence strain-partitioning at the scale of the western alpine belt. In the internal domain, this strain-partitioning, corresponds to extensional tectonics combinated with important strike-slip components while the external domain and the Po plain, located at the periphery, record an important shortening accomodated in surface by thrust and strike-slip faults. In order to understand the alpine present-day strain pattern, we propose and discuss a new crustal-scale cross-section performed along the Pelvoux-Dora Maira transect. The proeminent features of this crustal-scale geometry are : -the existence of a slice of cold and rigid mantle of Apulian origin beneath the Dora Maira massif. This rigid mantle is truncated in two distinct bodies by a system of deeply-rooted vertical faults related to the Insubric line. -these two main bodies of mantle acted as indenters driving the decoupling of the European crust and at least a part of the exhumation of the high-pressure metamorphic units. -the deep architecture is characterized by the stacking of crustal slices detached from the European lithosphere. Some of these slices represent tectonic extrusions within the overlying Piemont Schistes lustrés. -the Monviso eclogitized ophiolites are plunging up to 20 km depth below the Piemont schistes lustrés. In this geometrical model, the decoupling of the mantle identor drives the crustal-scale strain-partitioning of the western Alps. Indeed, the lower part of the rigid mantle transfers the compression onto the european foreland and is responsible for the present-day

  2. Iceland hotspot track in southeast Greenland causes huge present-day vertical viscoelastic motion of the bedrock

    NASA Astrophysics Data System (ADS)

    Khan, Shfaqat Abbas; Sasgen, Ingo; Bevis, Michael; van Dam, Tonie; Wahr, John; Bamber, Jonathan; Wouters, Bert; Helm, Veit; Willis, Michael; Csatho, Beata; Knudsen, Per; Kuipers Munneke, Peter; Kjær, Kurt

    2016-04-01

    The process of Glacial Isostatic Adjustment (GIA) represents the ongoing response of the solid Earth to past ice mass loss that occurred following the Last Glacial Maximum (LGM, ~21 ka B.P.). The magnitude of the GIA uplift depends on the temporal history of the ice load and is highly sensitive to variations in upper mantle viscosity. Greenland GIA is thought to be well contained and due to relative high viscosity, influence of more recent changes e.g. since the Little Ice Age have minor present-day effect (<2 mm/yr). Here we use data from the Greenland Global Positioning System (GPS) network to measure GIA. We identify an unexpected GIA anomaly of ~12 mm/yr in southeast Greenland, which we interpret as linked to a zone of warmer upper mantle caused by the Iceland hotspot track that would reduce the viscosity and produce greater viscoelastic uplift due to recent ice mass changes. We reconsider the evolution of the Greenland ice sheet since LGM and estimate a total ice mass loss equivalent to sea level rise of 4.9 m since LGM. Our observations suggest southeast and northwest Greenland, subject to present-day major ice loss, also contributed by significantly more mass loss on millennia scale than previously estimated.

  3. Present-day and future Antarctic ice sheet climate and surface mass balance in the Community Earth System Model

    NASA Astrophysics Data System (ADS)

    Lenaerts, Jan T. M.; Vizcaino, Miren; Fyke, Jeremy; van Kampenhout, Leo; van den Broeke, Michiel R.

    2016-02-01

    We present climate and surface mass balance (SMB) of the Antarctic ice sheet (AIS) as simulated by the global, coupled ocean-atmosphere-land Community Earth System Model (CESM) with a horizontal resolution of ˜1° in the past, present and future (1850-2100). CESM correctly simulates present-day Antarctic sea ice extent, large-scale atmospheric circulation and near-surface climate, but fails to simulate the recent expansion of Antarctic sea ice. The present-day Antarctic ice sheet SMB equals 2280 ± 131 {Gt year^{-1}} , which concurs with existing independent estimates of AIS SMB. When forced by two CMIP5 climate change scenarios (high mitigation scenario RCP2.6 and high-emission scenario RCP8.5), CESM projects an increase of Antarctic ice sheet SMB of about 70 {Gt year^{-1}} per degree warming. This increase is driven by enhanced snowfall, which is partially counteracted by more surface melt and runoff along the ice sheet's edges. This intensifying hydrological cycle is predominantly driven by atmospheric warming, which increases (1) the moisture-carrying capacity of the atmosphere, (2) oceanic source region evaporation, and (3) summer AIS cloud liquid water content.

  4. Present-day and future Antarctic ice sheet climate and surface mass balance in the Community Earth System Model

    NASA Astrophysics Data System (ADS)

    Lenaerts, Jan T. M.; Vizcaino, Miren; Fyke, Jeremy; van Kampenhout, Leo; van den Broeke, Michiel R.

    2016-09-01

    We present climate and surface mass balance (SMB) of the Antarctic ice sheet (AIS) as simulated by the global, coupled ocean-atmosphere-land Community Earth System Model (CESM) with a horizontal resolution of {˜ }1° in the past, present and future (1850-2100). CESM correctly simulates present-day Antarctic sea ice extent, large-scale atmospheric circulation and near-surface climate, but fails to simulate the recent expansion of Antarctic sea ice. The present-day Antarctic ice sheet SMB equals 2280 ± 131 {Gt year^{-1}}, which concurs with existing independent estimates of AIS SMB. When forced by two CMIP5 climate change scenarios (high mitigation scenario RCP2.6 and high-emission scenario RCP8.5), CESM projects an increase of Antarctic ice sheet SMB of about 70 {Gt year^{-1}} per degree warming. This increase is driven by enhanced snowfall, which is partially counteracted by more surface melt and runoff along the ice sheet's edges. This intensifying hydrological cycle is predominantly driven by atmospheric warming, which increases (1) the moisture-carrying capacity of the atmosphere, (2) oceanic source region evaporation, and (3) summer AIS cloud liquid water content.

  5. Isolation and prominent aboriginal maternal legacy in the present-day population of La Gomera (Canary Islands)

    PubMed Central

    Fregel, Rosa; Cabrera, Vicente M; Larruga, José M; Hernández, Juan C; Gámez, Alejandro; Pestano, Jose J; Arnay, Matilde; González, Ana M

    2015-01-01

    The present-day population structure of La Gomera is outstanding in its high aboriginal heritage, the greatest in the Canary Islands. This was earlier confirmed by both mitochondrial DNA and autosomal analyses, although genetic drift due to the fifteenth century European colonization could not be excluded as the main factor responsible. The present mtDNA study of aboriginal remains and extant samples from the six municipal districts of the island indeed demonstrates that the pre-Hispanic colonization of La Gomera by North African people involved a strong founder event, shown by the high frequency of the indigenous Canarian U6b1a lineage in the aboriginal samples (65%). This value is even greater than that observed in the extant population (44%), which in turn is the highest of all the seven Canary Islands. In contrast to previous results obtained for the aboriginal populations of Tenerife and La Palma, haplogroups related to secondary waves of migration were not detected in La Gomera aborigines, indicating that isolation also had an important role in shaping the current population. The rugged relief of La Gomera divided into several distinct valleys probably promoted subsequent aboriginal intra-insular differentiation that has continued after the European colonization, as seen in the present-day population structure observed on the island. PMID:25407001

  6. Unraveling the geochemistry of melts in exhumed mantle domains in present-day and fossil magma-poor rifted margins

    NASA Astrophysics Data System (ADS)

    Amann, Méderic; Ulrich, Marc; Autin, Julia; Manatschal, Gianreto; Epin, Marie-Eva; Müntener, Othmar; Boiron, Marie-Christine; Sauter, Daniel

    2016-04-01

    The role of magmatic processes occurring during the continental break-up and the onset of steady-state seafloor spreading are still a matter of debate. Beside the tectonic processes like stretching, thinning and exhumation, magmatic processes also play a key role in the evolution and breakup of magma-poor rifted margins. To unravel the impact of such processes, Ocean-Continent-Transitions (OCTs) are of particular interest. OCTs are complex areas where hyper-extended continental crust, exhumed mantle and proto-oceanic crust occur. All these domains have been identified and sampled in both present-day (Iberia/Newfoundland margins) and fossil margins (Platta/Err nappes). In this study, we present preliminary results that enable to characterize the nature of the mantle rocks and the melts found in the OCTs of these paleo- and present-day margins with the aim to investigate how the mantle evolves from initial exhumation to final lithospheric breaks. In OCTs two types of mantle rocks can be observed: (i) a « sub-continental type » free of syn-exhumation melt imprint preserving the early geochemical evolution, and (ii) a « refertilized type » characterized by melt infiltration and mantle-melt interaction. Melts from these domains have different major, trace element and isotopic compositions and can therefore be used to constrain how melt interacts with the mantle and to understand the role of magmatic processes in the break-up. We therefore summarized whole-rock, in-situ and isotopic analysis available in the literature from the Iberia/Newfoundland present-day margin system and completed the existing database with new additional data from the Iberia margin. These new data have been obtained using in-situ technics mainly on clinopyroxenites, serpentinized peridotites and gabbros of ODP drill cores. Around 200 new data have been acquired using the LA-ICPMS technic. Preliminary results show that clinopyroxenes in serpentinized peridodite breccia from ODP site 637A and

  7. Oxidation of dissolved iron under warmer, wetter conditions on Mars: Transitions to present-day arid environments

    NASA Astrophysics Data System (ADS)

    Burns, R. G.

    The copious deposits of ferric-iron assemblages littering the surface of bright regions of Mars indicate that efficient oxidative weathering reactions have taken place during the evolution of the planet. Because the kinetics of atmosphere-surface (gas-solid) reactions are considerably slower than chemical weathering reactions involving an aqueous medium, most of the oxidation products now present in the martian regolith probably formed when groundwater flowed near the surface. This paper examines how chemical weathering reactions were effected by climatic variations when warm, wet environments became arid on Mars. Analogies are drawn with hydrogeochemical and weathering environments on the Australian continent where present-day oxidation of iron is occurring in acidic ground water under arid conditions.

  8. Oxidation of dissolved iron under warmer, wetter conditions on Mars: Transitions to present-day arid environments

    NASA Technical Reports Server (NTRS)

    Burns, R. G.

    1993-01-01

    The copious deposits of ferric-iron assemblages littering the surface of bright regions of Mars indicate that efficient oxidative weathering reactions have taken place during the evolution of the planet. Because the kinetics of atmosphere-surface (gas-solid) reactions are considerably slower than chemical weathering reactions involving an aqueous medium, most of the oxidation products now present in the martian regolith probably formed when groundwater flowed near the surface. This paper examines how chemical weathering reactions were effected by climatic variations when warm, wet environments became arid on Mars. Analogies are drawn with hydrogeochemical and weathering environments on the Australian continent where present-day oxidation of iron is occurring in acidic ground water under arid conditions.

  9. A comparison of quality of present-day heat flow obtained from BHTs, Horner Plots of Malay Basin

    SciTech Connect

    Waples, D.W.; Mahadir, R. )

    1994-07-01

    Reconciling temperature data obtained from measurement of single BHT, multiple BHT at a single depth, RFTs, and DSTs, is very difficult. Quality of data varied widely, however DST data were assumed to be most reliable. Data from 87 wells was used in this study, but only 47 wells have DST data. BASINMOD program was used to calculate the present-day heat flow, using measured thermal conductivity and calibrated against the DST data. The heat flows obtained from the DST data were assumed to be correct and representative throughout the basin. Then, heat flows using (1) uncorrected RFT data, (2) multiple BHT data corrected by the Horner plot method, and (3) single BHT values corrected upward by a standard 10% were calculated. All of these three heat-flow populations had identically standard deviations to that for the DST data, but with significantly lower mean values. Correction factors were calculated to give each of the three erroneous populations the same mean value as the DST population. Heat flows calculated from RFT data had to be corrected upward by a factor of 1.12 to be equivalent to DST data; Horner plot data corrected by a factor of 1.18, and single BHT data by a factor of 1.2. These results suggest that present-day subsurface temperatures using RFT, Horner plot, and BHT data are considerably lower than they should be. The authors suspect qualitatively similar results would be found in other areas. Hence, they recommend significant corrections be routinely made until local calibration factors are established.

  10. Present-day oxidative subsidence of organic soils and mitigation in the Sacramento-San Joaquin Delta, California, USA

    NASA Astrophysics Data System (ADS)

    Deverel, Steven J.; Ingrum, Timothy; Leighton, David

    2016-05-01

    Subsidence of organic soils in the Sacramento-San Joaquin Delta threatens sustainability of the California (USA) water supply system and agriculture. Land-surface elevation data were collected to assess present-day subsidence rates and evaluate rice as a land use for subsidence mitigation. To depict Delta-wide present-day rates of subsidence, the previously developed SUBCALC model was refined and calibrated using recent data for CO2 emissions and land-surface elevation changes measured at extensometers. Land-surface elevation change data were evaluated relative to indirect estimates of subsidence and accretion using carbon and nitrogen flux data for rice cultivation. Extensometer and leveling data demonstrate seasonal variations in land-surface elevations associated with groundwater-level fluctuations and inelastic subsidence rates of 0.5-0.8 cm yr-1. Calibration of the SUBCALC model indicated accuracy of ±0.10 cm yr-1 where depth to groundwater, soil organic matter content and temperature are known. Regional estimates of subsidence range from <0.3 to >1.8 cm yr-1. The primary uncertainty is the distribution of soil organic matter content which results in spatial averaging in the mapping of subsidence rates. Analysis of leveling and extensometer data in rice fields resulted in an estimated accretion rate of 0.02-0.8 cm yr-1. These values generally agreed with indirect estimates based on carbon fluxes and nitrogen mineralization, thus preliminarily demonstrating that rice will stop or greatly reduce subsidence. Areas below elevations of -2 m are candidate areas for implementation of mitigation measures such as rice because there is active subsidence occurring at rates greater than 0.4 cm yr-1.

  11. A High-resolution 3D Geodynamical Model of the Present-day India-Asia Collision System

    NASA Astrophysics Data System (ADS)

    Kaus, B.; Baumann, T.

    2015-12-01

    We present a high-resolution, 3D geodynamic model of the present-day India-Asia collision system. The model is separated into multiple tectonic blocks, for which we estimate the first order rheological properties and the impact on the dynamics of the collision system. This is done by performing systematic simulations with different rheologies to minimize the misfit to observational constraints such as the GPS-velocity field. The simulations are performed with the parallel staggered grid FD code LaMEM using a numerical resolution of at least 512x512x256 cells to resolve dynamically important shear zones reasonably well. A fundamental part of this study is the reconstruction of the 3D present-day geometry of Tibet and the adjacent regions. Our interpretations of crust and mantle lithosphere geometry are jointly based on a globally available shear wave tomography (Schaeffer and Lebedev, 2013) and the Crust 1.0 model (Laske et al. http://igppweb.ucsd.edu/~gabi/crust1.html). We regionally refined and modified our interpretations based on seismicity distributions and focal mechanisms and incorporated regional receiver function studies to improve the accuracy of the Moho in particular. Results suggest that we can identify at least one "best-fit" solution in terms of rheological model properties that reproduces the observed velocity field reasonably well, including the strong rotation of the GPS velocity around the eastern syntax of the Himalaya. We also present model co-variances to illustrate the trade-offs between the rheological model parameters, their respective uncertainties, and the model fit. Schaeffer, A.J., Lebedev, S., 2013. Global shear speed structure of the upper mantle and transition zone. Geophysical Journal International 194, 417-449. doi:10.1093/gji/ggt095

  12. HLA Class I and Class II Alleles and Haplotypes Confirm the Berber Origin of the Present Day Tunisian Population

    PubMed Central

    Hajjej, Abdelhafidh; Almawi, Wassim Y.; Hattab, Lasmar; El-Gaaied, Amel; Hmida, Slama

    2015-01-01

    In view of its distinct geographical location and relatively small area, Tunisia witnessed the presence of many civilizations and ethnic groups throughout history, thereby questioning the origin of present-day Tunisian population. We investigated HLA class I and class II gene profiles in Tunisians, and compared this profile with those of Mediterranean and Sub-Sahara African populations. A total of 376 unrelated Tunisian individuals of both genders were genotyped for HLA class I (A, B) and class II (DRB1, DQB1), using reverse dot-blot hybridization (PCR-SSO) method. Statistical analysis was performed using Arlequin software. Phylogenetic trees were constructed by DISPAN software, and correspondence analysis was carried out by VISTA software. One hundred fifty-three HLA alleles were identified in the studied sample, which comprised 41, 50, 40 and 22 alleles at HLA-A,-B,-DRB1 and -DQB1 loci, respectively. The most frequent alleles were HLA-A*02:01 (16.76%), HLA-B*44:02/03 (17.82%), HLA-DRB1*07:01 (19.02%), and HLA-DQB1*03:01 (17.95%). Four-locus haplotype analysis identified HLA-A*02:01-B*50:01-DRB1*07:01-DQB1*02:02 (2.2%) as the common haplotype in Tunisians. Compared to other nearby populations, Tunisians appear to be genetically related to Western Mediterranean population, in particular North Africans and Berbers. In conclusion, HLA genotype results indicate that Tunisians are related to present-day North Africans, Berbers and to Iberians, but not to Eastern Arabs (Palestinians, Jordanians and Lebanese). This suggests that the genetic contribution of Arab invasion of 7th-11th century A.D. had little impact of the North African gene pool. PMID:26317228

  13. Complex Bedforms and Complex Water Masses: A Case Study from the Tertiary to Present-day, Pelotas Basin, Offshore Uruguay

    NASA Astrophysics Data System (ADS)

    Thompson, P.; Badalini, G.; Wrigley, S.; Walker, R.; Argent, J.; Hernandez-Molina, J.; de Santa Ana, H.; Soto, M.; Tomasini, J.

    2015-12-01

    varied both spatially and temporally and operated at various water depths. This complexity continues Present-day and is spectacularly imaged by pseudo time-lapse seismic data from the Present-day water column. These data, which are commonly neglected, highlight the true complexity of ocean currents and show how discrete dynamic water masses mix and move over time.

  14. Volcanoes and the environment: Lessons for understanding Earth's past and future from studies of present-day volcanic emissions

    NASA Astrophysics Data System (ADS)

    Mather, Tamsin A.

    2015-10-01

    Volcanism has affected the environment of our planet over a broad range of spatial (local to global) and temporal (< 1 yr to 100s Myr) scales and will continue to do so. As well as examining the Earth's geological record and using computer modelling to understand these effects, much of our knowledge of these processes comes from studying volcanism on the present-day planet. Understanding the full spectrum of possible routes and mechanisms by which volcanism can affect the environment is key to developing a realistic appreciation of possible past and potential future volcanic impact scenarios. This review paper seeks to give a synoptic overview of these potential mechanisms, focussing on those that we can seek to understand over human timescales by studying current volcanic activity. These effects are wide ranging from well-documented planetary-scale impacts (e.g., cooling by stratospheric aerosol veils) to more subtle or localised processes like ash fertilisation of ocean biota and impacts on cloud properties, atmospheric oxidant levels and terrestrial ecosystems. There is still much to be gained by studying present-day volcanic emissions. This review highlights the need for further work in three example areas. Firstly, to understand regional and arc-scale volcanic emissions, especially cycling of elements through subduction zones, more volatile measurements are needed to contribute to a fundamental and systematic understanding of these processes throughout geological time. Secondly, there is still uncertainty surrounding whether stratospheric ozone depletion following volcanic eruptions results solely from activation of anthropogenic halogen species. We should be poised to study future eruptions into the stratosphere with regard to their impacts and halogen load and work to improve our models and understanding of the relevant underlying processes within the Earth and the atmosphere. Thirdly, we lack a systematic understanding of trace metal volatility from magmas

  15. A novel GIS-based tool for estimating present-day ocean reference depth using automatically processed gridded bathymetry data

    NASA Astrophysics Data System (ADS)

    Jurecka, Mirosława; Niedzielski, Tomasz; Migoń, Piotr

    2016-05-01

    This paper presents a new method for computing the present-day value of the reference depth (dr) which is an essential input information for assessment of past sea-level changes. The method applies a novel automatic geoprocessing tool developed using Python script and ArcGIS, and uses recent data about ocean floor depth, sediment thickness, and age of oceanic crust. The procedure is multi-step and involves creation of a bathymetric dataset corrected for sediment loading and isostasy, delineation of subduction zones, computation of perpendicular sea-floor profiles, and statistical analysis of these profiles versus crust age. The analysis of site-specific situations near the subduction zones all around the world shows a number of instances where the depth of the oceanic crust stabilizes at a certain level before reaching the subduction zone, and this occurs at depths much lower than proposed in previous approaches to the reference depth issue. An analysis of Jurassic and Cretaceous oceanic lithosphere shows that the most probable interval at which the reference depth occurs is 5300-5800 m. This interval is broadly consistent with dr estimates determined using the Global Depth-Heatflow model (GDH1), but is significantly lower than dr estimates calculated on a basis of the Parsons-Sclater Model (PSM).

  16. MOCCA-SURVEY database I. Accreting white dwarf binary systems in globular clusters - I. Cataclysmic variables - present-day population

    NASA Astrophysics Data System (ADS)

    Belloni, Diogo; Giersz, Mirek; Askar, Abbas; Leigh, Nathan; Hypki, Arkadiusz

    2016-11-01

    In this paper, which is the first in a series of papers associated with cataclysmic variables and related objects, we introduce the CATUABA code, a numerical machinery written for analysis of the MOCCA simulations, and show some first results by investigating the present-day population of cataclysmic variables in globular clusters. Emphasis was given on their properties and the observational selection effects when observing and detecting them. In this work, we analysed in this work six models, including three with Kroupa distributions of the initial binaries. We found that for models with Kroupa initial distributions, considering the standard value of the efficiency of the common envelope phase adopted in BSE, no single cataclysmic variable was formed only via binary stellar evolution, i.e. in order to form them, strong dynamical interactions have to take place. We show and explain why this is inconsistent with observational and theoretical results. Our results indicate that the population of cataclysmic variables in globular clusters is, mainly, in the last stage of their evolution and observational selection effects can drastically change the expected number of observed cataclysmic variables. We show that the probability of observing them during the outbursts is extremely small and conclude that the best way of looking for cataclysmic variables in globular clusters is by searching for variabilities during quiescence, instead of during outbursts. For that, one would need a very deep observation which could reach magnitudes ≳27 mag. Finally, we argue that cataclysmic variables in globular clusters are not necessarily magnetic.

  17. Present-Day Atmospheric Simulations Using GISS ModelE: Comparison to In Situ, Satellite, and Reanalysis Data.

    NASA Astrophysics Data System (ADS)

    Schmidt, Gavin A.; Ruedy, Reto; Hansen, James E.; Aleinov, Igor; Bell, Nadine; Bauer, Mike; Bauer, Susanne; Cairns, Brian; Canuto, Vittorio; Cheng, Ye; Del Genio, Anthony; Faluvegi, Greg; Friend, Andrew D.; Hall, Tim M.; Hu, Yongyun; Kelley, Max; Kiang, Nancy Y.; Koch, Dorothy; Lacis, Andy A.; Lerner, Jean; Lo, Ken K.; Miller, Ron L.; Nazarenko, Larissa; Oinas, Valdar; Perlwitz, Jan; Perlwitz, Judith; Rind, David; Romanou, Anastasia; Russell, Gary L.; Sato, Makiko; Shindell, Drew T.; Stone, Peter H.; Sun, Shan; Tausnev, Nick; Thresher, Duane; Yao, Mao-Sung

    2006-01-01

    A full description of the ModelE version of the Goddard Institute for Space Studies (GISS) atmospheric general circulation model (GCM) and results are presented for present-day climate simulations (ca. 1979). This version is a complete rewrite of previous models incorporating numerous improvements in basic physics, the stratospheric circulation, and forcing fields. Notable changes include the following: the model top is now above the stratopause, the number of vertical layers has increased, a new cloud microphysical scheme is used, vegetation biophysics now incorporates a sensitivity to humidity, atmospheric turbulence is calculated over the whole column, and new land snow and lake schemes are introduced. The performance of the model using three configurations with different horizontal and vertical resolutions is compared to quality-controlled in situ data, remotely sensed and reanalysis products. Overall, significant improvements over previous models are seen, particularly in upper-atmosphere temperatures and winds, cloud heights, precipitation, and sea level pressure. Data model comparisons continue, however, to highlight persistent problems in the marine stratocumulus regions.

  18. New constraints on the present-day kinematics of the East African Rift from GPS and earthquake slip vector data

    NASA Astrophysics Data System (ADS)

    Hartnady, C.; Calais, E.; Ebinger, C.; Nocquet, J.

    2004-12-01

    The East African Rift (EAR), a major 5,000 km long and up to 1,000 km wide tectonic structure that marks the extensional boundary between the Nubian and Somalian plate, is interpreted either as a wide zone of uniformly distributed, diffuse deformation, or as a mosaic of microplates. Testing these models and quantifying the present-day kinematics of the EAR has so far resited investigation because of a critical lack of geodetic data within the EAR as well as on the surrounding Nubian and Somalian plates. Here, we present an updated GPS velocity field covering the Nubian and Somalian plates and combine it with earthquake slip vectors along the EAR in a joint inversion. Our objectives are to better constrain the Somalia/Nubia plate motion and to try to resolve block motions within the plate boundary zone. We find a Somalia/Nubia angular velocity similar to the one proposed by Fernandes et al. (EPSL, 222, 2004). We show that Tanzanian craton, nested between the western and eastern branches of the EAR and underlained by an upper mantle plume, can be modeled as an independent block, rotating counterclockwise w.r.t. Nubia. We discuss the implications of this kinematic model on the tectonics of the EAR.

  19. Atmospheric transport of persistent organic pollutants to and from the Arctic under present-day and future climate.

    PubMed

    Octaviani, Mega; Stemmler, Irene; Lammel, Gerhard; Graf, Hans F

    2015-03-17

    The long-term atmospheric cycling and fate of persistent organic pollutants under the influence of a changing climate is a concern. A GCM's realization of present-day (1970-1999) and future (2070-2099) climate, the latter under a medium scenario of greenhouse gas emissions, is used to study meridional transports and their correlations with the Arctic and North Atlantic Oscillations (AO and NAO). Regions of import and export maxima into the Arctic are identified along the Arctic Circle. It is found that, under future climate conditions, the net export of PCB153 out of the Arctic will increase. The meridional net flux pattern of this substance is expected to become independent of AO and NAO. For DDT, a trend of decreasing net Arctic import will reverse to an increasing trend 100 years after peak emission, which is partly due to more frequent AO and NAO positive phases. It is concluded that the long-term accumulation trends in the Arctic of other persistent pollutants, including so-called emerging pollutants, are subject to the substances' specific behavior and fate in the environment and need to be studied specifically. PMID:25686012

  20. Present-Day Crustal Vertical Motion Around the Ordos Block Constrained by Precise Leveling and GPS Data

    NASA Astrophysics Data System (ADS)

    Hao, Ming; Wang, Qingliang; Cui, Duxin; Liu, Liwei; Zhou, Lin

    2016-09-01

    Precise leveling data observed in the period of 1970-2014 around the Ordos block were collected and processed to estimate present-day crustal vertical movement. Vertical rates of 6 GPS sites were employed as a priori constraints to define the reference frame. The velocity field shows that the interior of the Ordos block moves upward at a rate of 3 mm/a as a stable block. With respect to the central Ordos, the grabens and rifts around the Ordos block are undergoing subsidence, while the northeastern and southwestern Ordos uplift at the average rates of 2 and 1 mm/a, respectively. To the southeastern margin of the Ordos block, the Weihe and southern Shanxi grabens are subsiding at the rates of 4-6 mm/a. The subsidence of the Shanxi graben indicates that the graben is experiencing extensional movement on a long timescale. To the northwestern margin of the Ordos block, the Hetao and Yinchuan rifts are subsiding at the rates of 2-3 mm/a. A 2-D buried faulting model is used to infer the normal or reverse dip-slip rates. Our solution shows that most of the normal slip rates along the faults in the grabens and rifts are ~2 mm/a.

  1. Global connections between aeolian dust, climate and ocean biogeochemistry at the present day and at the last glacial maximum

    NASA Astrophysics Data System (ADS)

    Maher, B. A.; Prospero, J. M.; Mackie, D.; Gaiero, D.; Hesse, P. P.; Balkanski, Y.

    2010-04-01

    Palaeo-dust records in sediments and ice cores show that wind-borne mineral aerosol ('dust') is strongly linked with climate state. During glacial climate stages, for example, the world was much dustier, with dust fluxes two to five times greater than in interglacial stages. However, the influence of dust on climate remains a poorly quantified and actively changing element of the Earth's climate system. Dust can influence climate directly, by the scattering and absorption of solar and terrestrial radiation, and indirectly, by modifying cloud properties. Dust transported to the oceans can also affect climate via ocean fertilization in those regions of the world's oceans where macronutrients like nitrate are abundant but primary production and nitrogen fixation are limited by iron scarcity. Dust containing iron, as fine-grained iron oxides/oxyhydroxides and/or within clay minerals, and other essential micronutrients (e.g. silica) may modulate the uptake of carbon in marine ecosystems and, in turn, the atmospheric concentration of CO 2. Here, in order to critically examine past fluxes and possible climate impacts of dust in general and iron-bearing dust in particular, we consider present-day sources and properties of dust, synthesise available records of dust deposition at the last glacial maximum (LGM); evaluate the evidence for changes in ocean palaeo-productivity associated with, and possibly caused by, changes in aeolian flux to the oceans at the LGM; and consider the radiative forcing effects of increased LGM dust loadings.

  2. Model sensitivity of ice flux over the grounding line to present-day climatic forcing and geothermal flux

    NASA Astrophysics Data System (ADS)

    Kleiner, Thomas; Humbert, Angelika

    2016-04-01

    Large uncertainties remain in the current and future contribution to sea level change from Antarctica from observations and numerical flow modelling. Within the SeaRISE project atmospheric, oceanic, and subglacial forcing scenarios were applied to different ice-sheet models to assess Antarctic ice sheet sensitivity over a 500 year timescale. The scenario results have been compared to the individual state of each model at the end of its spin-up. It has been shown, that the model results highly depend on the chosen climate forcing and spin-up strategy. Here we use the Parallel Ice Sheet Model (PISM) to perform spin-up simulations across different data sets for present-day boundary conditions for the Antarctic Ice Sheet (surface temperature, surface mass balance and geothermal flux). The utilized spin-up methods include free evolving and geometry constrained simulations. Here we present our analysis of the ice flux over the grounding line for each set-up and compare the fluxes from large drainage basin units with estimates derived from remote sensing.

  3. Present-day stress field on the South American slab underneath the Sandwich Plate (Southern Atlantic Ocean)

    NASA Astrophysics Data System (ADS)

    Giner-Robles, J. L.; Pérez-López, R.; Álvarez-Gómez, J. A.; Martínez-Díaz, J. J.; Rodríguez-Pascua, M. A.

    2009-04-01

    This work confirms the present-day principal stress orientation on the South Sandwich Plate (SSP) from the analysis of 331 earthquake focal mechanisms (Harvard catalog, HCMT). Principal stress orientation was deduced from earthquake focal mechanisms, examined by fault population analysis methods. The SSP plate is composed by oceanic crust limits an elliptical trench to the east (South Sandwich Trench), a ridge to the west and transforms faults towards the northern and southern boundaries. Within the trench region, the maximum horizontal shortening direction (SHMAX) rotates in trend in a clockwise direction, from NNE, in the northern boundary, to SSE in the southern boundary. Therefore, and keeping in mind the gradual rotation of SHMAX along the trench, three different areas were defined according to the prevailing focal mechanism type: (1) the North Zone, with SHMAX oriented N060°E and reverse and strike-slip focal mechanisms; (2) the Central Zone, with only reverse focal mechanism and SHMAX striking N080°E; (3) the South Zone, with SHMAX oriented N110°E and reverse and strike-slip focal geometry. Furthermore, the accommodation of the strain field in the Northern Zone of the South Sandwich Plate generates a subduction decoupling of the slab at, approximately, 70 km depth. In contrast, the South Zone slab exhibits a gradual stress and strain magnitude decreasing in depth. Finally, we define a sinistral strike-slip parallel to the southern boundary between the South Sandwich Plate and the Antarctic Plate, the South Sandwich Fault Zone.

  4. Evaluation of Present-day Aerosols over China Simulated from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)

    NASA Astrophysics Data System (ADS)

    Liao, H.; Chang, W.

    2014-12-01

    High concentrations of aerosols over China lead to strong radiative forcing that is important for both regional and global climate. To understand the representation of aerosols in China in current global climate models, we evaluate extensively the simulated present-day aerosol concentrations and aerosol optical depth (AOD) over China from the 12 models that participated in Atmospheric Chemistry & Climate Model Intercomparison Project (ACCMIP), by using ground-based measurements and satellite remote sensing. Ground-based measurements of aerosol concentrations used in this work include those from the China Meteorological Administration (CMA) Atmosphere Watch Network (CAWNET) and the observed fine-mode aerosol concentrations collected from the literature. The ground-based measurements of AOD in China are taken from the AErosol RObotic NETwork (AERONET), the sites with CIMEL sun photometer operated by Institute of Atmospheric Physics, Chinese Academy of Sciences, and from Chinese Sun Hazemeter Network (CSHNET). We find that the ACCMIP models generally underestimate concentrations of all major aerosol species in China. On an annual mean basis, the multi-model mean concentrations of sulfate, nitrate, ammonium, black carbon, and organic carbon are underestimated by 63%, 73%, 54%, 53%, and 59%, respectively. The multi-model mean AOD values show low biases of 20-40% at studied sites in China. The ACCMIP models can reproduce seasonal variation of nitrate but cannot capture well the seasonal variations of other aerosol species. Our analyses indicate that current global models generally underestimate the role of aerosols in China in climate simulations.

  5. Atmospheric transport of persistent organic pollutants to and from the Arctic under present-day and future climate.

    PubMed

    Octaviani, Mega; Stemmler, Irene; Lammel, Gerhard; Graf, Hans F

    2015-03-17

    The long-term atmospheric cycling and fate of persistent organic pollutants under the influence of a changing climate is a concern. A GCM's realization of present-day (1970-1999) and future (2070-2099) climate, the latter under a medium scenario of greenhouse gas emissions, is used to study meridional transports and their correlations with the Arctic and North Atlantic Oscillations (AO and NAO). Regions of import and export maxima into the Arctic are identified along the Arctic Circle. It is found that, under future climate conditions, the net export of PCB153 out of the Arctic will increase. The meridional net flux pattern of this substance is expected to become independent of AO and NAO. For DDT, a trend of decreasing net Arctic import will reverse to an increasing trend 100 years after peak emission, which is partly due to more frequent AO and NAO positive phases. It is concluded that the long-term accumulation trends in the Arctic of other persistent pollutants, including so-called emerging pollutants, are subject to the substances' specific behavior and fate in the environment and need to be studied specifically.

  6. Transient climate simulation from the Maunder Minimum to present day using prescribed changes in GHG, total/spectral solar irradiance and ozone

    NASA Astrophysics Data System (ADS)

    Spangehl, Thomas; Cubasch, Ulrich; Schimanke, Semjon

    A fully coupled AO-GCM including representation of the middle atmosphere is used for tran-sient simulation of climate from 1630 to 2000 AD. For better representation of changes in the UV/visible part of the solar spectrum an improved short-wave radiation scheme is implemented. The model is driven by changes in GHG concentrations, solar activity and volcanic eruptions. Solar variability is introduced via changes in total/spectral solar irradiance (TSI/SSI) and pre-scribed changes in stratospheric ozone. The secular trend in TSI is in the range of 0.1 percent increase from Maunder Minimum to present-day. Volcanic eruptions are represented via abrupt reduction in TSI. With the applied forcings the model does not simulate a clear reduction of the annual Northern Hemisphere (NH) mean near surface temperature during Maunder Minimum. By contrast the Dalton Minimum is characterized by distinct cooling and there is a significant raise of NH mean near surface temperature until the end of the 20th century. Focusing on the North Atlantic/European region the winter mean near surface temperature change pat-tern from Late Maunder Minimum (1675-1715) to present-day (1960-1990) reveals maximum warming over north-eastern Europe and cooling over the western North Atlantic with maxi-mum cooling west of Greenland. These changes can partly be explained by a shift of the NAO towards a more positive phase. The simulated changes in tropospheric circulation are discussed with special emphasize on the role of the solar forcing. Besides the stratospheric solar forcing which may affect NAO variability via downward propagation of the solar signal from the strato-sphere to the troposphere the magnitude of the secular trend in TSI might play a role. For the period from Maunder Minimum to present-day the simulation shows less near surface temper-ature increase especially over arctic regions when compared to simulations performed with the same model including the standard radiation scheme but

  7. Present-day deformation in NE Iran and the South Caspian constraint by Global Positioning System measurements

    NASA Astrophysics Data System (ADS)

    Mousavi, Z.; Walpersdorf, A.; Walker, R. T.; Tavakoli, F.; Pathier, E.; Nankali, H.; Nilfouroushan, F.; Aghamohammadi, A.; Djamour, Y.

    2012-12-01

    The continental collision between Arabia, the Eurasia and distribution of earthquake epicenters show that most of the deformation is accommodated within the political borders of Iran. In recent years, constraints from GPS, seismology and geological estimates of fault slip-rate have allowed considerable advances in understanding the rates and kinematics of faulting across many parts of Iran. However, until now, only little is known on the present-day distribution of strain across the eastern and northeastern parts of the country, such that it has been difficult to assess the rates of faulting, the related earthquake hazard, and the relationship between the active faults and the overall tectonic motions. This area is one of the most densely populated regions of Iran with almost 6.5 million habitants and a significant number of historical earthquakes like the Qumis 856 A.D earthquake with 200.000 victims. But while eastern Alborz and Kopeh Dagh are clearly regions of active faulting, a lack of instrumental earthquakes is presently observed, making this area particularly interesting for hazard assessment studies. The sparse GPS measurements in NE Iran provide only limited constraints on the applicability of different kinematic scenarios that have been proposed to explain the role of the observed faults. Here, we present a velocity field, composed from 47 GPS stations (20 campaign and 27 permanent), recording over up to 11 years, and covering the entire NE of Iran. This new GPS velocity field helps to investigate how northward directed Arabia-Eurasia shortening is accommodated at the northern boundary of the deforming zone. A regional deformation field for NE Iran has been estimated from the GPS measurements. It shows how the incoming ~7 mm/yr of NS shortening between Central Iran and Eurasia is accommodated in Alborz, Binalud and Kopeh Dagh. The shortening rate decreases toward the east and dies out at the Afghanistan border. The deformation pattern is contrasted along

  8. The Herschel view of the dominant mode of galaxy growth from z = 4 to the present day

    NASA Astrophysics Data System (ADS)

    Schreiber, C.; Pannella, M.; Elbaz, D.; Béthermin, M.; Inami, H.; Dickinson, M.; Magnelli, B.; Wang, T.; Aussel, H.; Daddi, E.; Juneau, S.; Shu, X.; Sargent, M. T.; Buat, V.; Faber, S. M.; Ferguson, H. C.; Giavalisco, M.; Koekemoer, A. M.; Magdis, G.; Morrison, G. E.; Papovich, C.; Santini, P.; Scott, D.

    2015-03-01

    our findings on the cosmic SFR history and on the origin of present-day stars: more than two-thirds of present-day stars must have formed in a regime dominated by the "main sequence" mode. As a consequence we conclude that, although omnipresent in the distant Universe, galaxy mergers had little impact in shaping the global star formation history over the last 12.5 billion years. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendices are available in electronic form at http://www.aanda.org

  9. Spatial distribution of precipitation annual cycles over South Africa in 10 CORDEX regional climate model present-day simulations

    NASA Astrophysics Data System (ADS)

    Favre, Alice; Philippon, Nathalie; Pohl, Benjamin; Kalognomou, Evangelia-Anna; Lennard, Christopher; Hewitson, Bruce; Nikulin, Grigori; Dosio, Alessandro; Panitz, Hans-Juergen; Cerezo-Mota, Ruth

    2016-03-01

    This study presents an evaluation of the ability of 10 regional climate models (RCMs) participating in the COordinated Regional climate Downscaling Experiment-Africa to reproduce the present-day spatial distribution of annual cycles of precipitation over the South African region and its borders. As found in previous studies, annual mean precipitation is quasi-systematically overestimated by the RCMs over a large part of southern Africa south of about 20°S and more strongly over South Africa. The spatial analysis of precipitation over the studied region shows that in most models the distribution of biases appears to be linked to orography. Wet biases are quasi-systematic in regions with higher elevation with inversely neutral to dry biases particularly in the coastal fringes. This spatial pattern of biases is particularly obvious during summer and specifically at the beginning of the rainy season (November and December) when the wet biases are found to be the strongest across all models. Applying a k-means algorithm, a classification of annual cycles is performed using observed precipitation data, and is compared with those derived from modeled data. It is found that the in-homogeneity of the spatial and temporal distribution of biases tends to impact the modeled seasonality of precipitation. Generally, the pattern of rainfall seasonality in the ensemble mean of the 10 RCMs tends to be shifted to the southwest. This spatial shift is mainly linked to a strong overestimation of convective precipitation at the beginning of the rainy season over the plateau inducing an early annual peak and to an underestimation of stratiform rainfall in winter and spring over southwestern South Africa.

  10. Multivariate spatio-temporal modelling for assessing Antarctica's present-day contribution to sea-level rise

    PubMed Central

    Zammit-Mangion, Andrew; Rougier, Jonathan; Schön, Nana; Lindgren, Finn; Bamber, Jonathan

    2015-01-01

    Antarctica is the world's largest fresh-water reservoir, with the potential to raise sea levels by about 60 m. An ice sheet contributes to sea-level rise (SLR) when its rate of ice discharge and/or surface melting exceeds accumulation through snowfall. Constraining the contribution of the ice sheets to present-day SLR is vital both for coastal development and planning, and climate projections. Information on various ice sheet processes is available from several remote sensing data sets, as well as in situ data such as global positioning system data. These data have differing coverage, spatial support, temporal sampling and sensing characteristics, and thus, it is advantageous to combine them all in a single framework for estimation of the SLR contribution and the assessment of processes controlling mass exchange with the ocean. In this paper, we predict the rate of height change due to salient geophysical processes in Antarctica and use these to provide estimates of SLR contribution with associated uncertainties. We employ a multivariate spatio-temporal model, approximated as a Gaussian Markov random field, to take advantage of differing spatio-temporal properties of the processes to separate the causes of the observed change. The process parameters are estimated from geophysical models, while the remaining parameters are estimated using a Markov chain Monte Carlo scheme, designed to operate in a high-performance computing environment across multiple nodes. We validate our methods against a separate data set and compare the results to those from studies that invariably employ numerical model outputs directly. We conclude that it is possible, and insightful, to assess Antarctica's contribution without explicit use of numerical models. Further, the results obtained here can be used to test the geophysical numerical models for which in situ data are hard to obtain. © 2015 The Authors. Environmetrics published by John Wiley & Sons Ltd. PMID:25937792

  11. The Secrets of the Nearest Starburst Cluster. II. The Present-Day Mass Function in NGC 3603

    NASA Astrophysics Data System (ADS)

    Stolte, Andrea; Brandner, Wolfgang; Brandl, Bernhard; Zinnecker, Hans

    2006-07-01

    Based on deep Very Large Telescope Infrared Spectrometer and Array Camera JHK photometry, we have derived the present-day mass function (MF) of the central starburst cluster NGC 3603 YC (Young Cluster) in the giant H II region NGC 3603. The effects of field contamination, individual reddening, and a possible binary contribution are investigated. The MF slopes resulting from the different methods are compared and lead to a surprisingly consistent cluster MF with a slope of Γ=-0.9+/-0.15. Analyzing different radial annuli around the cluster core, no significant change in the slope of the MF is observed. However, mass segregation in the cluster is evidenced by the increasing depletion of the high-mass tail of the stellar mass distribution with increasing radius. We discuss the indications of mass segregation with respect to the changes observed in the binned and cumulative stellar MFs and argue that the cumulative function, as well as the fraction of high- to low-mass stars, provides better indicators for mass segregation than the MF slope alone. Finally, the observed MF and starburst morphology of NGC 3603 YC are discussed in the context of massive local star-forming regions such as the Galactic center Arches cluster, R136/30 Dor in the LMC, and the Orion Trapezium cluster, all providing resolved templates for extragalactic star formation. Despite the similarity in the observed MF slopes, dynamical considerations suggest that the starburst clusters do not form gravitationally bound systems over a Hubble time. Both the environment (gravitational potential of the Milky Way) and the concentration of stars in the cluster core determine the dynamical stability of a dense star cluster, such that the long-term evolution of a starburst is not exclusively determined by the stellar evolution of its members, as frequently assumed for globular cluster systems. Based on observations obtained at the ESO Very Large Telescope on Paranal, Chile, under programs 63.I-0015 and 65.I

  12. Impact of the Yakutat indentor corner on present-day tectonics and fault activity in SE Alaska - SW Yukon

    NASA Astrophysics Data System (ADS)

    Mazzotti, S.; Marechal, A.; Ritz, J. F.; Ferry, M. A.

    2015-12-01

    We present an active tectonic model of the SE Alaska - SW Yukon region based principally on the integration of recent GPS velocity data and new fault-slip rates derived from geomorphology. In this region, the Yakutat collision results in complex tectonics with patterns of strain localization and strain partitioning that strongly vary across the various mountain ranges and active faults. We propose that deformation and fault activity in the St. Elias and Chugach Mountains are primarily controlled by the eastern syntaxis of the Yakutat collision, which produces a semi-radial tectonic pattern: Velocities, principal horizontal shortening rates, and maximum horizontal stress orientations rotate by 60 - 80 ° around the syntaxis, from roughly parallel to the relative Pacific - North America motion at the front of the collision to roughly orthogonal southeast of the syntaxis. The interaction between this strain pattern and major inherited tectonic structures inland of the collision zone (i.e., Denali and Duke River Faults) results in various reactivation modes of these structures. Specifically, the Denali Fault shows a very pronounced lateral variations of activity from ~12 mm/a of dextral slip rate in its central section to ~1 mm/a of mostly shortening slip rate along its southern section. This marked change of activity is associated with a possible relay system where the Duke River and Totschunda Faults accommodate a major part (8 - 12 mm/a) of the inland strain transfer directly in front of the syntaxis. This new tectonic model retains some questions, in particular regarding the mechanisms of deformation and strain transfer (1) from the syntaxis to the Duke River - Totschunda system and (2) at the junction between Totschunda and Denali Faults. Numerical models of present-day deformation may help address these issues and provide information about relative strength of the various crustal and inherited fault elements of this system.

  13. Historical and Present Day Mercury Contamination From Gold Mining in Three Feeding Guilds of Bats From the Peruvian Amazon

    NASA Astrophysics Data System (ADS)

    Kumar, A.; Divoll, T.

    2014-12-01

    Miners in many countries use mercury as an amalgam to separate gold from river sediments. In the last twenty years the price of gold has risen and the number of small-scale, artisanal gold mining operations in the Amazon basin have also increased. The influx of mercury into natural river systems has detrimental consequences for the surrounding ecosystem and for organisms, particularly those at higher trophic levels. Toxic mercury levels have been shown to impair reproductive, neurological and behavioral functioning of organisms. I used bats (Chiroptera) as a mammalian model system to study mercury contamination and accumulation due to gold mining from field caught and museum collection specimens in Amazonian Perú and showed that: (1) Total mercury concentrations in Amazonian bat species have increased over time since the 1920's; (2) Bat species from sites with current active mining have higher concentrations of mercury than non-mining sites, with some species having levels exceeding those considered toxic for mammals; (3) Higher trophic levels of bats (piscivores and insectivores) bioaccumulate more mercury than bats of lower trophic levels (frugivores); (4) Bats located in present day uncontaminated sites have the same mercury levels as bats collected in the 1920's from the Amazon basin. The variety of bat feeding guilds allowed for a comparison of how mercury accumulation is affected by diet within one taxonomic order. The novel use of museum specimens allowed for a look back into the historical timeline of mercury contamination in the Amazon basin. Bats represent a new and exciting study system since, like humans, they are mammals and should therefore show similar neurochemical and behavioral responses to this toxic element.

  14. Life detection at a Mars analogue site of present-day serpentinization in the Tablelands Ophiolite of Newfoundland (Invited)

    NASA Astrophysics Data System (ADS)

    Morrill, P. L.; Szponar, N.; Brazelton, W. J.; Woodruff, Q.; Schrenk, M. O.; Bower, D. M.; Steele, A.

    2010-12-01

    The Tableland Ophiolite was created during the collision of Laurentia and Gondwana continents ca. 470 million years ago. Ultramafic mantle rocks, from the ancient sea bed that once separated these continents, were thrusted westward onto the old continental margin, which is now Western Newfoundland. Weathering due to recent glaciations has left large areas of ultramafic rock at the surface and created fissures for fluid flow. As a result serpentinization is occurring as fresh water penetrates the unaltered ultramafic rock. Serpentinization is of particular interest because, through hydration of ultramafic rock, this reaction produces H2 and the reducing conditions necessary for abiogenic hydrocarbon synthesis, while also producing conditions amenable for chemolithotrophic life. Therefore sites of active serpentinization can be the source of either abiogenic or biogenic organics, or both. Serpentinization is a suspected (past or present) source of (detected or putative) hydrocarbons on Mars, Titan and Europa, hence these astrobodies may be potentially habitable or once habitable environments. The Tablelands Ophiolite is an analogue site that is ideal for testing methods of life detection in an extreme environment of high pH and low microbial biomass characteristic of sites of serpentinization. Multiple ultrabasic reducing springs characteristic of present-day serpentinization have been identified and characterized based on their geochemistry and microbiology. Field-based instruments were deployed for the detection of microbial activity (ATP), microbial cell wall material, and mineralogy, in yet untested high pH and low biomass environment. In this talk I will give an overview of the in situ measurements of life detection and put these measurements in context of geochemistry, microbiology, carbon source and reaction pathways, and I will discuss what we have learned that will help us plan for future mission measurements.

  15. Present-day kinematics and fault slip rates in eastern Iran, derived from 11 years of GPS data

    NASA Astrophysics Data System (ADS)

    Walpersdorf, A.; Manighetti, I.; Mousavi, Z.; Tavakoli, F.; Vergnolle, M.; Jadidi, A.; Hatzfeld, D.; Aghamohammadi, A.; Bigot, A.; Djamour, Y.; Nankali, H.; Sedighi, M.

    2014-02-01

    We analyze new GPS data spanning 11 years at 92 stations in eastern Iran. We use these data to analyze the present-day kinematics and the slip rates on most seismogenic faults in eastern Iran. The east Lut, west Lut, Kuhbanan, Anar, Dehshir, and Doruneh faults are confirmed as the major faults and are found to currently slip laterally at 5.6 ± 0.6, 4.4 ± 0.4, 3.6 ± 1.3, 2.0 ± 0.7, 1.4 ± 0.9, and 1.3 ± 0.8 mm/yr, respectively. Slip is right-lateral on the ~NS striking east Lut, west Lut, Kuhbanan, Anar, and Dehshir faults and left-lateral on the ~EW Doruneh fault. The ~NS faults slice the eastern Iranian crust into five blocks that are moving northward at 6-13 mm/yr with respect to the stable Afghan crust at the eastern edge of the collision zone. The collective behavior of the ~NS faults might thus allow the Arabian promontory to impinge northward into the Eurasian crust. The ~NS faults achieve additional NS shortening by rotating counterclockwise in the horizontal plane, at current rates up to 0.8°/Ma. Modeling the GPS and available geological data with a block rotation model suggests that the rotations have been going on at a similar rate (1 ± 0.4°/Ma) over the last 12 Ma. We identify large strains at the tips of the rotating east Lut, west Lut, and Kuhbanan faults, which we suspect to be responsible for the important historical and instrumental seismicity in those zones.

  16. Reverse-current effect in present-day models of solar flares: Theory and high-accuracy observations

    NASA Astrophysics Data System (ADS)

    Gritsyk, P. A.; Somov, B. V.

    2014-08-01

    We propose an accurate analytical model for the source of hard X-ray emission from a flare in the form of a "thick target" with a reverse current to explain the results of present-day observations of solar flares onboard the GOES, Hinode, RHESSI, and TRACE satellites. The model, one-dimensional in coordinate space and two-dimensional in velocity space, self-consistently takes into account the fact that the beam electrons lose the kinetic energy of their motion along the magnetic field almost without any collisions under the action of the reverse-current electric field. Some of the electrons return from the emission source to the acceleration region without losing the kinetic energy of their transverse motion. Based on the observed hard X-ray bremsstrahlung spectrum, the model allows the injection spectrum of accelerated electrons to be reconstructed with a high accuracy. As an example, we consider the white-light flare of December 6, 2006, which was observed with a high spatial resolution in the optical wavelength range at the main maximum of hard X-ray emission. Within the framework of our model, we show that to explain the hard X-ray spectrum, the flux density of the energy transferred by electrons with energies above 18 keV was ˜3 × 1013 erg cm-2 s-1. This exceeds the habitual values typical of the classical model of a thick target without a reverse current by two orders of magnitude. The electron density in the beam is also very high: ˜1011 cm-3. A more careful consideration of plasma processes in such dense electron beams is needed when the physical parameters of a flare are calculated.

  17. Modeling of Present-Day Atmosphere and Ocean Non-Tidal De-Aliasing Errors for Future Gravity Mission Simulations

    NASA Astrophysics Data System (ADS)

    Bergmann-Wolf, I.; Dobslaw, H.; Mayer-Gürr, T.

    2015-12-01

    A realistically perturbed synthetic de-aliasing model consistent with the updated Earth System Model of the European Space Agency (Dobslaw et al., 2015) is now available for the years 1995 -- 2006. The data-set contains realizations of (i) errors at large spatial scales assessed individually for periods between 10 -- 30, 3 -- 10, and 1 -- 3 days, the S1 atmospheric tide, and sub-diurnal periods; (ii) errors at small spatial scales typically not covered by global models of atmosphere and ocean variability; and (iii) errors due to physical processes not represented in currently available de-aliasing products. The error magnitudes for each of the different frequency bands are derived from a small ensemble of four atmospheric and oceanic models. In order to demonstrate the plausibility of the error magnitudes chosen, we perform a variance component estimation based on daily GRACE normal equations from the ITSG-Grace2014 global gravity field series recently published by the University of Graz. All 12 years of the error model are used to calculate empirical error variance-covariance matrices describing the systematic dependencies of the errors both in time and in space individually for five continental and four oceanic regions, and daily GRACE normal equations are subsequently employed to obtain pre-factors for each of those matrices. For the largest spatial scales up to d/o = 40 and periods longer than 24 h, errors prepared for the updated ESM are found to be largely consistent with noise of a similar stochastic character contained in present-day GRACE solutions. Differences and similarities identified for all of the nine regions considered will be discussed in detail during the presentation.Dobslaw, H., I. Bergmann-Wolf, R. Dill, E. Forootan, V. Klemann, J. Kusche, and I. Sasgen (2015), The updated ESA Earth System Model for future gravity mission simulation studies, J. Geod., doi:10.1007/s00190-014-0787-8.

  18. Performance of regional climate models in simulations of present-day Irish climate: Implications for constructing future scenarios

    NASA Astrophysics Data System (ADS)

    Foley, A. M.

    2009-04-01

    Simulations of present-day (1961-1990) climate from 19 regional climate model experiments have been compared to the observed baseline climate for Ireland. These simulations, driven by global climate models, are obtained through the EC PRUDENCE (Prediction of Regional scenarios and Uncertainties for Defining EuropeaN Climate change risks and Effects) project. The ability to represent the statistics of Irish climate has been assessed, both temporally (comparisons of meteorological year, seasonal mean and seasonal variance) and spatially (seasonal covariation and pattern-analysis) for two key meteorological parameters, that of temperature and precipitation. For the average meteorological year (30-year averages of each month), mean temperatures are found to be within 1.5˚ C of observations, except in winter, when temperatures are overestimated by up to 2.5˚ C. Temporal variation is also not well-represented by some models in winter. Conversely, temporal variation in precipitation is most poorly simulated in summer. Seasonal variance is the area in which greatest inter-model variability is shown. Ratio of observed variance to modeled variance ranges from weak (0.5 or less) to very strong (greater than 0.7) in both seasons, and for both parameters. Spatially, temperature is over-estimated throughout Ireland, by up to 4.6˚ C in winter and 2.7˚ C in summer in individual grid cells from some models. Precipitation is found to be both under and over-estimated, with grid cell biases ranging from -2.5 mm/day to 4.2 mm/day in winter and from -1.2 mm/day to 1.8 mm/day in summer. While skill at representing the spatial precipitation pattern is found to be very strong in 16 out of 19 experiments in winter, only 2 of those experiments show the same level of skill in summer. Errors are identified in all individual models, both systematic and random. While using an ensemble average overcomes some of these deficiencies, the optimal approach is to correct systematic errors

  19. Investigating the Present Day Cosmic Dust Flux at the Earth's Surface: Initial Results from the Kwajalein Micrometeorite Collection

    NASA Technical Reports Server (NTRS)

    Wozniakiewicz, P. J.; Bradley, J. P.; Price, M. C.; Zolensky, M. E.; Ishii, H. A.; Brownlee, D. E.; Russell, S. S.

    2014-01-01

    Examination of impact craters on the Long Duration Exposure Facility satellite indicate a present day micrometeoroid flux of approx. 30,000 tonnes [1 after 2]. But what portion of this material arrives at the Earth's surface as micrometeorites? Studies of available micrometeorite collections from deep sea sediments [e.g. 3], Greenland blue ice [e.g. 4] and the South Pole water well [e.g. 1] may be complicated by terrestrial weathering and, in some cases, collection bias (magnetic separation for deep sea sediments) and poorly constrained ages. We have recently set up a micrometeorite collection station on Kwajalein Island in the Republic of the Marshall Islands in the Pacific Ocean, using high volume air samplers to collect particles directly from the atmosphere. By collecting in this way, the terrestrial age of the particles is known, the weathering they experience is minimal, and we are able to constrain particle arrival times. Collecting at this location also exploits the considerably reduced anthropogenic background [5]. Method: High volume air samplers were installed on top of the two-story airport building on Kwajalein. These were fitted with polycarbonate membrane filters with 5µm diameter perforations. The flow rates were set to 0.5m3/min, and filters were changed once a week. After collection, filters were washed to remove salt and concentrate particles [see 5] in preparation for analysis by SEM. Results and Discussion: A selection of filters have been prepared and surveyed. Due to their ease of identification our initial investigations have focused on particles resembling cosmic spherules. The spheres can be divided into three main groups: 1. Silicate spherules rich in Al, Ca, K and Na (to varying degrees), 2. Silicate spherules rich in Mg and Fe and 3. Fe-rich spherules. Group 1 spherules are often vesiculated and can occur as aggregates. They are similar in appearance and composition to volcanic microspheres [e.g. 6] and are thus likely terrestrial in

  20. Present-Day Kinematics of Crustal Deformation of the Walker Lane and Central Nevada, Derived From GPS Data

    NASA Astrophysics Data System (ADS)

    Nyst, M. C.; Hammond, W. C.

    2002-12-01

    The Walker Lane (WL) is a zone of tectonic deformation located between the western edge of the Basin and Range province (BR) in Nevada and the Sierra Nevada in California. It extends from ~36o in California to ~41o latitude in western Nevada and eastern California. The WL is of great interest for the study of intra-plate deformation because it accommodates the transfer of NW directed motion of the Sierra Nevada block to roughly E-W extension in the eastern BR. In addition, by connecting the Eastern California Shear Zone (ECSZ) with more northern zones of dextral shear such as the Central Nevada Seismic Zone (CNSZ) the WL plays an important role in the accommodation of motion between the Pacific and North America plates. Previous studies of the present-day crustal deformation in this area focused on sub-regions of the WL. We study the whole WL and utilize a relatively dense GPS velocity set (of 121 stations with data from 1992 to 2002) to model crustal deformation. The GPS data set consists of the western Nevada data of Svarc et al. (JGR, 2002), the BR data of Thatcher et al. (Science, 1999) and the ECSZ data of Gan et al. (JGR, 2000). Principal strain rates derived from data subsets agree with those of previous studies: In the northern WL WNW-ESE extension averages ~24 nstrain/yr and NNE-SSW contraction averages ~9 nstrain/yr. Since the average fault trend is NNW, the resulting strain rates may be indicative for dextral transtensional slip. In the central WL WNW-ESE extension (~27 nstrain/yr) and NNE-SSW contraction (~11 nstrain/yr) together with the predominantly ENE trending faults suggest sinistral transtensional slip. In the southern WL ENE-WSW extension (~25 nstrain/yr), NNW-SSE contraction (~30 nstrain/yr) and NNW trending faults correspond to dextral slip. To determine the spatial variation of the crustal deformation field we solve for a self-consistent continuous velocity gradient field from which both strain and rotation rate fields are derived. In general

  1. Impact of urban emission on air-quality over central Europe: present day and future emissions perspective

    NASA Astrophysics Data System (ADS)

    Huszar, Peter; Belda, Michal; Halenka, Tomas; Karlicky, Jan

    2016-04-01

    The purpose of the study is to quantify the impact of present-day and future urban emission from central European cities on the regional air-quality (AQ), based on a modeling couple of the regional climate model RegCM4.2 and the chemistry transport model CAMx, including two-way interactions. A series of simulations was carried out for the present (2001-2010) decade and two future decades (2026-2035 and 2046-2055) either with all urban emissions included (base case) or without considering urban emissions. As we are interested on the impact of emission changes only, the impact of different driving meteorological conditions in the future (due to climate change) are not considered. The emissions used is the TNO MEGAPOLI European emission database that includes country/sector based scenarios for years 2030 and 2050, which were used for the encompassing decades. Further, the sensitivity of ozone production to urban emissions was examined by performing reduction experiments with -20% emission perturbation of NOx and/or NMVOC. The model was also validated using surface measurements of key pollutants. Selected air-quality measures were used as metrics describing the cities emission impact on regional air pollution. Due to urban emissions, significant ozone titration occurs over cities while over rural areas further from, ozone production is modeled, mainly in terms of number of exceedances and accumulated exceedances over the threshold of 40 ppbv. Urban NOx, SO2 and PM2.5 emissions also significantly contribute to concentrations in the cities themselves (up to 50-70% for NOx and SO2 , and up to 55% for PM2.5), but the contribution is large over rural areas as well (10-20%). Although air pollution over cities is largely determined by the local urban emissions, considerable (often a few tens of %) fraction of the concentration is attributable to other sources from rural areas and minor cities. The future urban emission AQ fingerprint is, in general, slightly smaller than in

  2. PRESENT-DAY MASS FUNCTION OF SIX SMALL MAGELLANIC CLOUD INTERMEDIATE-AGE AND OLD STAR CLUSTERS

    SciTech Connect

    Glatt, Katharina; Grebel, Eva K.; Jordi, Katrin; Gallagher, John S. III; Harbeck, Daniel; Da Costa, Gary; Clementini, Gisella; Tosi, Monica; Nota, Antonella; Sabbi, Elena; Sirianni, Marco

    2011-08-15

    We determined the present-day mass functions (PDMFs) of the five intermediate-age star clusters Lindsay 1, Kron 3, NGC 339, NGC 416, and Lindsay 38 and the old star cluster NGC 121 in the Small Magellanic Cloud (SMC) based on observations with the Hubble Space Telescope Advanced Camera for Surveys. The global PDMFs are well matched by Salpeter-like power laws from their main-sequence turnoffs to {approx}0.6 M{sub sun} with a power-law exponent {alpha} ranging from 1.51 {+-} 0.11 (Lindsay 1) to 2.29 {+-} 0.15 (NGC 339). We derive total stellar masses of {approx}10{sup 5} M{sub sun}, except for Lindsay 38, whose mass is of the order of {approx}10{sup 4} M{sub sun}. Differences between the PDMFs most likely reflect the varying stages of dynamical evolution of the clusters. These SMC clusters do not follow the {alpha} versus concentration parameter c correlation as found for Galactic globular clusters of similar mass. This might be an age effect or due to their location in a galaxy where bulge and disk crossings do not play a role. No correlation is found between {alpha} and the cluster core and tidal radii (r{sub c} and r{sub t} , respectively), the half-light radii r{sub h} , age, central surface brightness, metallicity, and galactocentric radius r{sub gc}. All six clusters mass-segregated to different degrees. The two clusters Lindsay 1 and Kron 3 barely show signs for mass segregation, but have low-mass star deficient global PDMFs and might be the remnants of star clusters whose outer parts were stripped. A trend exists between the degree of mass segregation and the ratio age/relaxation time t{sub r,h}, which indicates the stage of dynamical evolution for a cluster. Our data thus suggest that the SMC clusters in the present sample had a range of initial densities and presumably different amounts of mass loss that led to different rates of dynamical evolution. The clusters' positions in the r{sub h,m}/r{sub t} versus r{sub 0}/r{sub h,m} plane imply that all of the

  3. Hazard responses in the pre-industrial era: vulnerability and resilience of traditional societies to volcanic disasters and the implications for present-day disaster planning

    NASA Astrophysics Data System (ADS)

    Sangster, Heather

    2014-05-01

    A major research frontier in the study of natural hazard research involves unravelling the ways in which societies have reacted historically to disasters, and how such responses influence current policies of disaster reduction. For societies it is common to classify responses to natural hazards into: pre-industrial (folk); industrial; and post-industrial (comprehensive) responses. Pre-industrial societies are characterised by: a pre-dominantly rural location; an agricultural economic focus; artisan handicrafts rather than industrial production, parochialism, with people rarely travelling outside their local area and being little affected by external events and a feudal or semi-feudal social structure. In the past, hazard assessment focused on the physical processes that produced extreme and potentially damaging occurrences, however from the middle of the twenty-first century research into natural hazards has been cast within a framework defined by the polarities (or opposites) of vulnerability and resilience, subject to a blend of unique environmental, social, economic and cultural forces in hazardous areas, that either increase or decrease the impact of extreme events on a given society. In the past decade research of this type has been facilitated by a 'revolution' of source materials across a range of languages and in a variety of electronic formats (e.g. official archives; major contemporary and near-contemporary publications - often available as reprints; national and international newspapers of record; newsreel-films; and, photographs) and in the introduction of more reliable translation software (e.g. Systrans) that provides far more scope to the researcher in the study of natural hazards than was the case even a few years ago. Knowledge of hazard responses in the pre-industrial era is, not only important in its own right because it reveals indigenous strategies of coping, but also informs present-day disaster planners about how people have reacted to past

  4. From past sailors' eras to the present day: scurvy as a surprising manifestation of an uncommon gastrointestinal disease.

    PubMed

    Branquinho, Diogo Ferreira; Pinto-Gouveia, Miguel; Mendes, Sofia; Sofia, Carlos

    2015-01-01

    A 45-year-old man presented with follicular exanthema in his lower limbs, alternating bowel habits and significant weight loss. His medical history included seronegative arthritis, bipolar disease and an inconclusive diagnostic laparoscopy. Diagnostic work up revealed microcytic anaemia and multivitamin deficiency. Skin biopsy of the exanthema suggested scurvy. Owing to these signs of malabsorption, upper endoscopy with duodenal biopsies was performed, exhibiting villous atrophy and extensive periodic acid-Schiff-positive material in the lamina propria, therefore diagnosing Whipple's disease (WD). After starting treatment with ceftriaxone and co-trimoxazole, an impressive recovery was noted, as the wide spectrum of malabsorption signs quickly disappeared. After a year of antibiotics, articular and cutaneous manifestations improved, allowing the patient to stop taking corticosteroids and antidepressants. This truly unusual presentation reflects the multisystemic nature of WD, often leading to misdiagnosis of other entities. Scurvy is a rare finding in developed countries, but its presence should raise suspicion for small bowel disease. PMID:26376699

  5. Present-day submarine hydrothermal activity in the Taupo-Rotorua Zone (Bay of Plenty, New Zealand)

    SciTech Connect

    Osipenko, A.B.; Egorov, Yu.O.; Fazlullin, S.M.; Gavrilenko, G.M.; Shul`kin, V.I.; Chertkova, L.V.

    1994-09-01

    We made detailed descriptions of the structure and material composition of sedimentary and water columns in the vicinity of active submarine hydrothermal activity in the southern part of the Bay of Plenty (North Island, New Zealand). Geophysical methods revealed that the hydrothermal system is confined to a tectonically distinct zone with a sedimentary cover characterized by complex structure. Chemical and mineralogical investigations confirmed that the activity of underwater vents exerts no substantial regional influence on the composition and features of ore mineralization in these formations. It is shown that essentially hydrothermal formations distinguishable within areas of otherwise monotypic sediments directly coincide with zones of hydrothermal discharge in the ocean floor. The absence of pronounced hydrothermal anomalies, together with the presence of {open_quotes}tongues{close_quotes} of anomalous concentrations of water-soluble gases suggests that the discharges are primarily hydrothermal in character.

  6. From past sailors' eras to the present day: scurvy as a surprising manifestation of an uncommon gastrointestinal disease.

    PubMed

    Branquinho, Diogo Ferreira; Pinto-Gouveia, Miguel; Mendes, Sofia; Sofia, Carlos

    2015-09-16

    A 45-year-old man presented with follicular exanthema in his lower limbs, alternating bowel habits and significant weight loss. His medical history included seronegative arthritis, bipolar disease and an inconclusive diagnostic laparoscopy. Diagnostic work up revealed microcytic anaemia and multivitamin deficiency. Skin biopsy of the exanthema suggested scurvy. Owing to these signs of malabsorption, upper endoscopy with duodenal biopsies was performed, exhibiting villous atrophy and extensive periodic acid-Schiff-positive material in the lamina propria, therefore diagnosing Whipple's disease (WD). After starting treatment with ceftriaxone and co-trimoxazole, an impressive recovery was noted, as the wide spectrum of malabsorption signs quickly disappeared. After a year of antibiotics, articular and cutaneous manifestations improved, allowing the patient to stop taking corticosteroids and antidepressants. This truly unusual presentation reflects the multisystemic nature of WD, often leading to misdiagnosis of other entities. Scurvy is a rare finding in developed countries, but its presence should raise suspicion for small bowel disease.

  7. [Present-day advantages of computerized tomography in the diagnosis of chronic inflammatory changes in paranasal sinuses in flying personnel].

    PubMed

    Vasil'ev, A Iu; Bessonov, O V; Shevchenko, A G; Grebennikov, A N

    1995-01-01

    The paper demonstrates the diagnostic effectiveness of computer tomography for discovering chronic productive sinus in flying personnel. On the evidence mounted from 190 patients with paranasal sinus, the computer tomography semiotics of various chronic inflammatory processes in sinus has been developed and the comparative analysis of computer tomography and classic X-ray and ultrasonic scanning of sinus has been fulfilled. The computer tomography appears to have high diagnostic potentials for revealing pathology in paranasal sinus in flying personnel. It was confirmed that the technique enables to examine normal anatomy of paranasal sinus, support or invalidate previous diagnosis, and to ascertain the spread and the character of process, visualize alterations in soft and bone tissues and plan surgery.

  8. The impact of modern migrations on present-day multi-ethnic Argentina as recorded on the mitochondrial DNA genome

    PubMed Central

    2011-01-01

    Background The genetic background of Argentineans is a mosaic of different continental ancestries. From colonial to present times, the genetic contribution of Europeans and sub-Saharan Africans has superposed to or replaced the indigenous genetic 'stratum'. A sample of 384 individuals representing different Argentinean provinces was collected and genotyped for the first and the second mitochondrial DNA (mtDNA) hypervariable regions, and selectively genotyped for mtDNA SNPs. This data was analyzed together with additional 440 profiles from rural and urban populations plus 304 from Native American Argentineans, all available from the literature. A worldwide database was used for phylogeographic inferences, inter-population comparisons, and admixture analysis. Samples identified as belonging to hg (hg) H2a5 were sequenced for the entire mtDNA genome. Results Phylogenetic and admixture analyses indicate that only half of the Native American component in urban Argentineans might be attributed to the legacy of extinct ancestral Argentineans and that the Spanish genetic contribution is slightly higher than the Italian one. Entire H2a5 genomes linked these Argentinean mtDNAs to the Basque Country and improved the phylogeny of this Basque autochthonous clade. The fingerprint of African slaves in urban Argentinean mtDNAs was low and it can be phylogeographically attributed predominantly to western African. The European component is significantly more prevalent in the Buenos Aires province, the main gate of entrance for Atlantic immigration to Argentina, while the Native American component is larger in North and South Argentina. AMOVA, Principal Component Analysis and hgs/haplotype patterns in Argentina revealed an important level of genetic sub-structure in the country. Conclusions Studies aimed to compare mtDNA frequency profiles from different Argentinean geographical regions (e.g., forensic and case-control studies) should take into account the important genetic

  9. Historic, pre-European settlement, and present-day contribution of wild ruminants to enteric methane emissions in the United States.

    PubMed

    Hristov, A N

    2012-04-01

    The objectives of this analysis were to estimate historic (pre-European settlement) enteric CH(4) emissions from wild ruminants in the contiguous United States and compare these with present-day CH(4) emissions from farmed ruminants. The analysis included bison, elk (wapiti), and deer (white-tailed and mule). Wild ruminants such as moose, antelope (pronghorn), caribou, and mountain sheep and goat were not included in the analysis because their natural range is mostly outside the contiguous United States or because they have relatively small population sizes. Data for presettlement and present-day population sizes, animal BW, feed intake, and CH(4) emission factors were adopted from various sources. Present-day CH(4) emissions from livestock were from recent United States Environmental Protection Agency estimates. The most important factor determining CH(4) emissions from wild ruminants in the presettlement period was the size of the bison population. Overall, enteric CH(4) emissions from bison, elk, and deer in the presettlement period were about 86% (assuming bison population size of 50 million) of the current CH(4) emissions from farmed ruminants in the United States. Present-day CH(4) emissions from wild ruminants (bison, elk, and deer) were estimated at 0.28 Tg/yr, or 4.3% of the emissions from domestic ruminants. Due to its population size (estimated at 25 million), the white-tailed deer is the most significant present-day wild ruminant contributor to enteric CH(4) emissions in the contiguous United States. PMID:22178852

  10. Historic, pre-European settlement, and present-day contribution of wild ruminants to enteric methane emissions in the United States.

    PubMed

    Hristov, A N

    2012-04-01

    The objectives of this analysis were to estimate historic (pre-European settlement) enteric CH(4) emissions from wild ruminants in the contiguous United States and compare these with present-day CH(4) emissions from farmed ruminants. The analysis included bison, elk (wapiti), and deer (white-tailed and mule). Wild ruminants such as moose, antelope (pronghorn), caribou, and mountain sheep and goat were not included in the analysis because their natural range is mostly outside the contiguous United States or because they have relatively small population sizes. Data for presettlement and present-day population sizes, animal BW, feed intake, and CH(4) emission factors were adopted from various sources. Present-day CH(4) emissions from livestock were from recent United States Environmental Protection Agency estimates. The most important factor determining CH(4) emissions from wild ruminants in the presettlement period was the size of the bison population. Overall, enteric CH(4) emissions from bison, elk, and deer in the presettlement period were about 86% (assuming bison population size of 50 million) of the current CH(4) emissions from farmed ruminants in the United States. Present-day CH(4) emissions from wild ruminants (bison, elk, and deer) were estimated at 0.28 Tg/yr, or 4.3% of the emissions from domestic ruminants. Due to its population size (estimated at 25 million), the white-tailed deer is the most significant present-day wild ruminant contributor to enteric CH(4) emissions in the contiguous United States.

  11. REE and Hf distribution among mineral phases in the CV-CK clan: A way to explain present-day Hf isotopic variations in chondrites

    NASA Astrophysics Data System (ADS)

    Martin, Céline; Debaille, Vinciane; Lanari, Pierre; Goderis, Steven; Vandendael, Isabelle; Vanhaecke, Frank; Vidal, Olivier; Claeys, Philippe

    2013-11-01

    as the degree of metamorphism increases (30% for types 3 and 4, less than 5% in type 6). In contrast to Lu, Hf is mainly hosted by silicates with little contribution from phosphates throughout the CK metamorphic sequence. A significant part of Sm and Nd are stored in phosphates in types 3-5, and these elements behave similarly during CK chondrite metamorphism. That explains the robustness of the Sm/Nd ratios in chondrites through metamorphism, and the slight discrepancies observed in the present-day isotopic Nd values in chondrites. On the contrary, Lu and Hf are borne by several different minerals and consequently they are redistributed during metamorphism-induced recrystallization. The Lu/Hf ratios are therefore significantly disturbed during chondrites metamorphism, leading to the high discrepancies observed in present-day Hf isotopic values in chondrites.

  12. Present-day plate motions

    NASA Technical Reports Server (NTRS)

    Minster, J. B.; Jordan, T. H.

    1977-01-01

    A data set comprising 110 spreading rates, 78 transform fault azimuths and 142 earthquake slip vectors was inverted to yield a new instantaneous plate motion model, designated RM2. The mean averaging interval for the relative motion data was reduced to less than 3 My. A detailed comparison of RM2 with angular velocity vectors which best fit the data along individual plate boundaries indicates that RM2 performs close to optimally in most regions, with several notable exceptions. On the other hand, a previous estimate (RM1) failed to satisfy an extensive set of new data collected in the South Atlantic Ocean. It is shown that RM1 incorrectly predicts the plate kinematics in the South Atlantic because the presently available data are inconsistent with the plate geometry assumed in deriving RM1. It is demonstrated that this inconsistency can be remedied by postulating the existence of internal deformation with the Indian plate, although alternate explanations are possible.

  13. [Present-day 90Sr and 137Cs contamination levels of soil and agricultural products in the East-Urals Radioactive Trace area].

    PubMed

    Kazachenok, N N; Popova, I Ia; Kostiuchenko, V A; Mel'nikov, V S; Usol'tsev, D V

    2009-01-01

    Data represent present-day 90Sr and 137Cs contamination levels of soil and agricultural products (grain, vegetables and forage crops, milk and meat) in the East-Urals Radioactive Trace area, and the accumulation coefficients of these radionuclides in cash crop.

  14. Estimations of historical atmospheric mercury concentrations from mercury refining and present-day soil concentrations of total mercury in Huancavelica, Peru.

    PubMed

    Robins, Nicholas A; Hagan, Nicole; Halabi, Susan; Hsu-Kim, Heileen; Gonzales, Ruben Dario Espinoza; Morris, Mark; Woodall, George; Richter, Daniel deB; Heine, Paul; Zhang, Tong; Bacon, Allan; Vandenberg, John

    2012-06-01

    Detailed Spanish records of cinnabar mining and mercury production during the colonial period in Huancavelica, Peru were examined to estimate historical health risks to the community from exposure to elemental mercury (Hg) vapor resulting from cinnabar refining operations. Between 1564 and 1810, nearly 17,000 metric tons of Hg were released to the atmosphere in Huancavelica from Hg production. AERMOD was used with estimated emissions and source characteristics to approximate historic atmospheric concentrations of mercury vapor. Modeled 1-hour and long-term concentrations were compared with present-day inhalation reference values for elemental Hg. Estimated 1-hour maximum concentrations for the entire community exceeded present-day occupational inhalation reference values, while some areas closest to the smelters exceeded present-day emergency response guideline levels. Estimated long-term maximum concentrations for the entire community exceeded the EPA Reference Concentration (RfC) by a factor of 30 to 100, with areas closest to the smelters exceeding the RfC by a factor of 300 to 1000. Based on the estimated historical concentrations of Hg vapor in the community, the study also measured the extent of present-day contamination throughout the community through soil sampling and analysis. Total Hg in soils sampled from 20 locations ranged from 1.75 to 698 mg/kg and three adobe brick samples ranging from 47.4 to 284 mg/kg, consistent with other sites of mercury mining and use. The results of the soil sampling indicate that the present-day population of Huancavelica is exposed to levels of mercury from legacy contamination which is currently among the highest worldwide, consequently placing them at potential risk of adverse health outcomes. PMID:22542225

  15. Post World War II orcharding creates present day DDT-problems in The Sørfjord (Western Norway)--a case study.

    PubMed

    Ruus, Anders; Green, Norman W; Maage, Amund; Amundsen, Carl Einar; Schøyen, Merete; Skei, Jens

    2010-10-01

    The Sørfjord has a long history of agriculture and industry, and environmental monitoring has been conducted for decades, comprising analyses of contaminants in mussel, fish and sediments. DDT was used as an insecticide in orchards surrounding the fjord between World War II and 1970. Since the early 1990 s, elevated concentrations of DDT were found in mussels and fish. Unexpectedly, DDT-concentrations increased towards present day, despite the discontinuation of use. The highest concentrations in mussels (in 2006) corresponded to about two orders of magnitude higher than background. Analyses of sediment core sections also indicated increased input towards present day. Shifts in climatic parameters, as well as increased amounts of soil dissolved organic carbon following a decline in atmospheric sulphate deposition may have contributed to this phenomenon. We warrant the need for increased knowledge of the effects of alterations in variables acting regionally and globally on the disposition of contaminants in ecosystems.

  16. Simulation of the present-day atmospheric ozone, odd nitrogen, chlorine and other species using a coupled 2-D model in isentropic coordinates

    NASA Technical Reports Server (NTRS)

    Yang, H.; Olaguer, E.; Tung, K. K.

    1991-01-01

    A zonally averaged two-dimensional model for chemical species in the atmosphere (Olaguer et al., 1990), with coupled dynamics, radiation transfer, and chemistry, is used to study the present-day atmospheric ozone, odd nitrogen, chlorine, other species. The model utilizes all zonally averaged physical equations of momentum, energy, and mass and determines self-consistently the advective and diffusive tranasport parameters from the temperature specific to the period of observation. A comparison of the model results with observations showed good agreement.

  17. Formation of hyperextended rifted margins: Insights from flexural isostatic structural-stratigraphic modeling and observations from present-day rifted margins

    NASA Astrophysics Data System (ADS)

    Mohn, Geoffroy; Kusznir, Nick; Manatschal, Gianreto

    2014-05-01

    The understanding of how continental lithosphere extends, thins and ruptures leading to the formation of a new divergent plate boundary represent a fundamental question in Earth Sciences. In particular the mechanisms controlling the extreme pre-breakup stretching and thinning of the continental crust and lithosphere, documented at many present-day rifted margins, are still poorly known. Many questions remain of the fundamental processes controlling the extensional deformation of the continental crust and lithosphere, including fault geometries and their evolution in space and time, the occurrence of decoupling horizons within the continental crust and the importance of depth-dependent lithosphere thinning processes. We investigate the control of these key factors on continental crust and lithosphere thinning processes by combining seismic reflection and drill-hole observations from present-day Iberia-Newfoundland rifted margins with flexural isostatic forward tectonic and stratigraphic modeling. These observations made at present-day rifted margins constrain the input parameters used in the flexural isostatic forward modeling. At the same time, the forward tectonic and stratigraphic modeling provides validation of the interpretation of the seismic reflection data. Through this modeling, we produce isostatically and thermally balanced sections reproducing the geometries observed along the Iberia-Newfoundland rifted margins. Our results suggest that crustal and lithospheric thinning results from the combination of both pure- and simple-shear deformation. The model predicts the critical role of intra-crustal decoupling horizons confirming the importance of depth-dependent thinning through polyphased rifting events.

  18. The influence of dynamic vegetation on the present-day simulation and future projections of the South Asian summer monsoon in the HadGEM2 family

    NASA Astrophysics Data System (ADS)

    Martin, G. M.; Levine, R. C.

    2012-11-01

    Various studies have shown the importance of Earth System feedbacks in the climate system and the necessity of including these in models used for making climate change projections. The HadGEM2 family of Met Office Unified Model configurations combines model components which facilitate the representation of many different processes within the climate system, including atmosphere, ocean and sea ice, and Earth System components including the terrestrial and oceanic carbon cycle and tropospheric chemistry. We examine the climatology of the Asian summer monsoon in present-day simulations and in idealised climate change experiments. Members of the HadGEM2 family are used, with a common physical framework (one of which includes tropospheric chemistry and an interactive terrestrial and oceanic carbon cycle), to investigate whether such components affect the way in which the monsoon changes. We focus particularly on the role of interactive vegetation in the simulations from these model configurations. Using an atmosphere-only HadGEM2 configuration, we investigate how the changes in land cover which result from the interaction between the dynamic vegetation and the model systematic rainfall biases affect the Asian summer monsoon, both in the present-day and in future climate projections. We demonstrate that the response of the dynamic vegetation to biases in regional climate, such as lack of rainfall over tropical dust-producing regions, can affect both the present-day simulation and the response to climate change forcing scenarios.

  19. The influence of dynamic vegetation on the present-day simulation and future projections of the South Asian summer monsoon in the HadGEM2 family

    NASA Astrophysics Data System (ADS)

    Martin, G. M.; Levine, R. C.

    2012-08-01

    Various studies have shown the importance of Earth System feedbacks in the climate system and the necessity of including these in models used for making climate change projections. The HadGEM2 family of Met Office Unified Model configurations combines model components which facilitate the representation of many different processes within the climate system, including atmosphere, ocean and sea ice, and Earth System components including the terrestrial and oceanic carbon cycle and tropospheric chemistry. We examine the climatology of the Asian summer monsoon in present-day simulations and in idealised climate change experiments in which a quadrupling of CO2 is applied as a step change. Members of the HadGEM2 family are used, with a common physical framework, one of which includes tropospheric chemistry and an interactive terrestrial and oceanic carbon cycle, to investigate whether such components affect the way in which the monsoon changes. We focus particularly on the role of interactive vegetation in the simulations from these model configurations. Using an atmosphere-only HadGEM2 configuration, we investigate how the changes in land cover which result from the interaction between the dynamic vegetation and the model systematic rainfall biases affect the Asian summer monsoon, both in the present-day and in future climate projections. We demonstrate that the response of the dynamic vegetation to biases in regional climate, such as lack of rainfall over tropical dust-producing regions, can affect both the present-day simulation and the response to climate change forcing scenarios.

  20. Using GPS and Absolute Gravity Observations to Separate the Effects of Present-day and Pleistocene Ice-mass Changes in South East Greenland

    NASA Astrophysics Data System (ADS)

    van Dam, T. M.; Francis, O.; Wahr, J. M.; Khan, S. A.; Bevis, M. G.; van den Broeke, M.

    2015-12-01

    Precise estimates of the present-day rates and accelerations of ice-mass loss from the polar ice-sheets are important for predicting potential changes in sea level. Current predictions of 21st century sea level change are limited by, among other things, their ability to precisely capture the effects of global warming on the Greenland ice sheet (GrIS). One method for constraining the mass loss on the GrIS is to make measurements of vertical crustal uplift rates from bedrock around the edge of the ice sheet. Using only GPS observations of crustal displacement, it is impossible to separate the uplift driven by present day mass changes from that due to ice mass changes in the past, e.g. the extensive retreat of the ice sheets since the Last Glacial Maximum (LGM) or even ice sheet changes during the Little Ice Age. By making measurements of both gravity and surface motion at a bedrock site, the viscoelastic effects could be removed from the observations and we would be able to constrain present day ice mass changes. In this presentation we discuss the results of an experiment to collect surface displacement and absolute gravity observations from southeast Greenland to separate the elastic and viscoelastic signals. We find that the glacial isostatic adjustment signal in this region is positive, contrary to the negative signal predicted by all existing viscosity and ice history models.

  1. Preindustrial to Present-Day Changes in Tropospheric Hydroxyl Radical and Methane Lifetime from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)

    NASA Technical Reports Server (NTRS)

    Naik, V.; Voulgarakis, A.; Fiore, A. M.; Horowitz, L. W.; Lamarque, J.-F.; Lin, M.; Prather, M. J.; Young, P. J.; Bergmann, D.; Cameron-Smith, P. J.; Cionni, I.; Collins, W. J.; Dalsoren, S. B.; Doherty, R.; Eyring, V.; Faluvegi, G.; Folberth, G. A.; Josse, B.; Lee, Y. H.; MacKenzie, I. A.; Nagashima, T.; vanNoije, T. P. C.; Plummer, D. A.; Righi, M.; Rumbold, S. T.; Skeie, R.; Shindell, D. T.; Stevenson, D. S.; Strode, S.; Sudo, K.; Szopa, S.; Zeng, G.

    2013-01-01

    We have analysed time-slice simulations from 17 global models, participating in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), to explore changes in present-day (2000) hydroxyl radical (OH) concentration and methane (CH4) lifetime relative to preindustrial times (1850) and to 1980. A comparison of modeled and observation-derived methane and methyl chloroform lifetimes suggests that the present-day global multi-model mean OH concentration is overestimated by 5 to 10% but is within the range of uncertainties. The models consistently simulate higher OH concentrations in the Northern Hemisphere (NH) compared with the Southern Hemisphere (SH) for the present-day (2000; inter-hemispheric ratios of 1.13 to 1.42), in contrast to observation-based approaches which generally indicate higher OH in the SH although uncertainties are large. Evaluation of simulated carbon monoxide (CO) concentrations, the primary sink for OH, against ground-based and satellite observations suggests low biases in the NH that may contribute to the high north–south OH asymmetry in the models. The models vary widely in their regional distribution of present-day OH concentrations (up to 34%). Despite large regional changes, the multi-model global mean (mass-weighted) OH concentration changes little over the past 150 yr, due to concurrent increases in factors that enhance OH (humidity, tropospheric ozone, nitrogen oxide (NOx) emissions, and UV radiation due to decreases in stratospheric ozone), compensated by increases in OH sinks (methane abundance, carbon monoxide and non-methane volatile organic carbon (NMVOC) emissions). The large inter-model diversity in the sign and magnitude of preindustrial to present-day OH changes (ranging from a decrease of 12.7% to an increase of 14.6%) indicate that uncertainty remains in our understanding of the long-term trends in OH and methane lifetime. We show that this diversity is largely explained by the different ratio of the

  2. Lyα-emitting Galaxies at z = 2.1 in ECDF-S: Building Blocks of Typical Present-day Galaxies?

    NASA Astrophysics Data System (ADS)

    Guaita, Lucia; Gawiser, Eric; Padilla, Nelson; Francke, Harold; Bond, Nicholas A.; Gronwall, Caryl; Ciardullo, Robin; Feldmeier, John J.; Sinawa, Shawn; Blanc, Guillermo A.; Virani, Shanil

    2010-05-01

    ) = 11.5+0.4 -0.5, which are among the lowest mass halos yet probed at this redshift. We used the Sheth and Tormen conditional mass function to study the descendants of these LAEs and found that their typical present-day descendants are local galaxies with L* properties, like the Milky Way. Based on observations obtained at Cerro Tololo Inter-American Observatory, a division of the National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation.

  3. Estimating heat stress from climate-based indicators: present-day biases and future spreads in the CMIP5 global climate model ensemble

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Ducharne, A.; Sultan, B.; Braconnot, P.; Vautard, R.

    2015-08-01

    The increased exposure of human populations to heat stress is one of the likely consequences of global warming, and it has detrimental effects on health and labor capacity. Here, we consider the evolution of heat stress under climate change using 21 general circulation models (GCMs). Three heat stress indicators, based on both temperature and humidity conditions, are used to investigate present-day model biases and spreads in future climate projections. Present day estimates of heat stress indicators from observational data shows that humid tropical areas tend to experience more frequent heat stress than other regions do, with a total frequency of heat stress 250-300 d yr-1. The most severe heat stress is found in the Sahel and south India. Present-day GCM simulations tend to underestimate heat stress over the tropics due to dry and cold model biases. The model based estimates are in better agreement with observation in mid to high latitudes, but this is due to compensating errors in humidity and temperature. The severity of heat stress is projected to increase by the end of the century under climate change scenario RCP8.5, reaching unprecedented levels in some regions compared with observations. An analysis of the different factors contributing to the total spread of projected heat stress shows that spread is primarily driven by the choice of GCMs rather than the choice of indicators, even when the simulated indicators are bias-corrected. This supports the utility of the multi-model ensemble approach to assess the impacts of climate change on heat stress.

  4. Comment on ``A new estimate for present-day Cocos-Caribbean plate motion: Implications for slip along the Central American volcanic arc'' by Charles DeMets

    NASA Astrophysics Data System (ADS)

    Guzmán-Speziale, Marco; Gómez, Juan Martín

    2002-10-01

    We comment on ``A new estimate for present-day Cocos-Caribbean plate motion: Implications for slip along the Central American volcanic arc'' by Charles DeMets. We find the following inconsistencies in his model: Components of relative motion along the arc are small and variable, not uniform. There is no single surface faulting and earthquakes occur on faults along and perpendicular to the arc. Earthquakes also stop in the middle of the arc. Geometrically, the model calls for buttressing, but there is no evidence for this.

  5. [The specific features of present-day children's physical development in the estimation of the functional sizes of furniture for pupils].

    PubMed

    Khramtsov, P I; Strokina, A N; Sotnikova, E N; Butareva, I I; Moldovanov, V V

    2009-01-01

    The authors made mass anthropometric surveys in 923 first-to-fourth-form pupils and determined the values of 5 variables for height groups 2, 3, and 4, used to justify the functional sizes of furniture for pupils: the length of a shoulder slope above the seat, that of an elbow slope above the seat, that of a popliteal space slope above the floor, the distance from the chair hack to the popliteal space, and the highest pelvic width. Differences were found in the anthropometric values in the present-day junior pupils and the equals in age of the early 1970s. The present-day children are characterized by changes in body proportions (a decrease in height and an increase in the length of the shin and femur), which should be kept in mind on optimizing the working place of pupils. It is suggested that popliteal space length rather than the currently applied height should be used as a fitting ratio of anthropometric characteristics to the functional sizes of furniture for pupils.

  6. Morphological indicators of growth stages in carbonates platform evolution: comparison between present-day and Miocene platforms of Northern Borneo, Malaysia.

    NASA Astrophysics Data System (ADS)

    Pierson, B.; Menier, D.; Ting, K. K.; Chalabi, A.

    2012-04-01

    Satellite images of present-day reefs and carbonate platforms of the Celebes Sea, east of Sabah, Malaysia, exhibit large-scale features indicative of the recent evolution of the platforms. These include: (1) multiple, sub-parallel reef rims at the windward margin, suggestive of back-stepping of the platform margin; (2) contraction of the platform, possibly as a result of recent sea level fluctuations; (3) colonization of the internal lagoons by polygonal reef structures and (4) fragmentation of the platforms and creation of deep channels separating platforms that used to be part of a single entity. These features are analogue to what has been observed on seismic attribute maps of Miocene carbonate platforms of Sarawak. An analysis of several growth stages of a large Miocene platform, referred to as the Megaplatform, shows that the platform evolves in function of syn-depositional tectonic movements and sea level fluctuations that result in back-stepping of the margin, illustrated by multiple reef rims, contraction of the platform, the development of polygonal structures currently interpreted as karstic in origin and fragmentation of the megaplatform in 3 sub-entities separated by deep channels that precedes the final demise of the whole platform. Comparing similar features on present-day to platforms and Miocene platforms leads to a better understanding of the growth history of Miocene platforms and to a refined predictability of reservoir and non-reservoir facies distribution.

  7. Structural Evolution of the India-Arabia Plate Boundary from Miocene to Present-Day (NW Indian Ocean) and Comparison with the Dead Sea Fault (Eastern Mediterranean Sea).

    NASA Astrophysics Data System (ADS)

    Rodriguez, M.; Huchon, P.; Chamot Rooke, N.; Fournier, M.; Delescluse, M.; Ben Avraham, Z.; Ten Brink, U. S.

    2014-12-01

    Arabia is bounded by the Dead Sea Transform (DST) to the west and by the Owen Fracture Zone (OFZ) to the east. These present-day major strike-slip fault systems activated during the Plio-Pleistocene, which contrasts with the age of inception of strike-slip motion, assumed to begin around 13-18 Ma for the DST and around 20 Ma at the edge of the Owen-Murray Ridge (OMR) for the India-Arabia plate boundary. This discrepancy between the age of the active strike-slip systems and the age of inception of strike-slip motion raises the question of the kinematic driver for the transition between successive generations of strike-slip faults. Using a recent mutibeam and seismic dataset crossing the OFZ and the OMR, we provide a new geodynamic framework for the Miocene to present-day structural evolution of the India-Arabia plate boundary, and highlight some similarities with the structural evolution of the DST. We first document a Late Miocene episode of uplift of the OMR uplift along the Miocene India-Arabia plate boundary. The onset of this uplift is coeval with a plate reorganization event marked by the onset of intra-plate deformation in the Central Indian Ocean. The OFZ emplaced around 3 Ma, with major pull-apart basins opening (20°N Basin, Dalrymple Trough) dated at 2.4 Ma by far-field correlation with ODP Sites. The opening of pull-apart basins is coeval with the last structural reorganization of the Makran accretionnary wedge, marked by the regional M-unconformity, and with a major intensification of the Indian monsoon. A Late Miocene episode of folding is also recognized at the Lebanon ranges prior to the onset of the present-day DST, which occurred in the Late Pliocene-Early Pleistocene. The similarities between the geological history of the India-Arabia plate boundary and the DST in the Late Miocene and the Late Pliocene-Early Pleistocene suggest that both plate boundaries recorded the same kinematic changes. Late Miocene (i.e. Tortonian) deformation is widely

  8. Evaluating CMIP5 ocean biogeochemistry and Southern Ocean carbon uptake using atmospheric potential oxygen: Present-day performance and future projection

    NASA Astrophysics Data System (ADS)

    Nevison, C. D.; Manizza, M.; Keeling, R. F.; Stephens, B. B.; Bent, J. D.; Dunne, J.; Ilyina, T.; Long, M.; Resplandy, L.; Tjiputra, J.; Yukimoto, S.

    2016-03-01

    Observed seasonal cycles in atmospheric potential oxygen (APO ~ O2 + 1.1 CO2) were used to evaluate eight ocean biogeochemistry models from the Coupled Model Intercomparison Project (CMIP5). Model APO seasonal cycles were computed from the CMIP5 air-sea O2 and CO2 fluxes and compared to observations at three Southern Hemisphere monitoring sites. Four of the models captured either the observed APO seasonal amplitude or phasing relatively well, while the other four did not. Many models had an unrealistic seasonal phasing or amplitude of the CO2 flux, which in turn influenced APO. By 2100 under RCP8.5, the models projected little change in the O2 component of APO but large changes in the seasonality of the CO2 component associated with ocean acidification. The models with poorer performance on present-day APO tended to project larger net carbon uptake in the Southern Ocean, both today and in 2100.

  9. Differential responses of calcifying and non-calcifying epibionts of a brown macroalga to present-day and future upwelling pCO2.

    PubMed

    Saderne, Vincent; Wahl, Martin

    2013-01-01

    Seaweeds are key species of the Baltic Sea benthic ecosystems. They are the substratum of numerous fouling epibionts like bryozoans and tubeworms. Several of these epibionts bear calcified structures and could be impacted by the high pCO2 events of the late summer upwellings in the Baltic nearshores. Those events are expected to increase in strength and duration with global change and ocean acidification. If calcifying epibionts are impacted by transient acidification as driven by upwelling events, their increasing prevalence could cause a shift of the fouling communities toward fleshy species. The aim of the present study was to test the sensitivity of selected seaweed macrofoulers to transient elevation of pCO2 in their natural microenvironment, i.e. the boundary layer covering the thallus surface of brown seaweeds. Fragments of the macroalga Fucus serratus bearing an epibiotic community composed of the calcifiers Spirorbis spirorbis (Annelida) and Electra pilosa (Bryozoa) and the non-calcifier Alcyonidium hirsutum (Bryozoa) were maintained for 30 days under three pCO2 conditions: natural 460 ± 59 µatm, present-day upwelling1193 ± 166 µatm and future upwelling 3150 ± 446 µatm. Only the highest pCO2 caused a significant reduction of growth rates and settlement of S. spirorbis individuals. Additionally, S. spirorbis settled juveniles exhibited enhanced calcification of 40% during daylight hours compared to dark hours, possibly reflecting a day-night alternation of an acidification-modulating effect by algal photosynthesis as opposed to an acidification-enhancing effect of algal respiration. E. pilosa colonies showed significantly increased growth rates at intermediate pCO2 (1193 µatm) but no response to higher pCO2. No effect of acidification on A. hirsutum colonies growth rates was observed. The results suggest a remarkable resistance of the algal macro-epibionts to levels of acidification occurring at present day upwellings in the Baltic. Only extreme

  10. Quantitative Study of the Present-Day Climate of the Middle Tennessee Elk Watershed Area From Global and Regional Climate Model Simulations

    NASA Astrophysics Data System (ADS)

    Kebede, G.

    2015-12-01

    As part of a wider hydro climatic modeling research, we studied the spatial and temporal variability of precipitation and temperature over the Middle Tennessee Elk watershed and its environs using regional climate model simulations over the past 30 years. Three sets of simulations with the Hadley Center's regional climate model (PRECIS) were carried out for the present day climate (1980-2010) at a resolution of 25km covering the southeastern U.S. These three sets simulations are driven by lateral boundary conditions taken from ERA-Interim reanalysis, and two global climate models (HadCM3 and ECHAM5) respectively. For validation, high resolution observed daily data sets from North American Land-Data Assimilation System (NLDAS) and Climate Research Unit, CRU data are used. Preliminary results show that the spatial distribution of the present-day seasonal mean rainfall and temperature, simulated by PRECIS, are not only consistent with NLDAS and CRU but also captured fine scale spatial structures that are missing in the global model simulations due to their coarse resolution. In addition, the annual cycle and intera-anual variability, particularly that of temperature, are reasonably well reproduced by the PRECIS. When comparing the PRECIS simulations with the driving GCMs, PRECIS is sensitive to the choice of the driving GCM, suggesting a careful selection of driving GCM based on the current climate performance for the use of future climate impact assessment. Quantitative understanding of the climate system and better estimation of the fresh water balance over the Middle Tennessee Elk watershed is a vital corner stone for a sustainable economic growth of the region over the coming decades.

  11. Seismological Structure of the 1.8Ga Trans-Hudson Orogen of North America and its affinity to present-day Tibet

    NASA Astrophysics Data System (ADS)

    Gilligan, A.; Bastow, I. D.; Darbyshire, F. A.

    2015-12-01

    How tectonic processes operated and changed through the Precambrian is debated: what was the nature and scale of orogenic events and were they different on the younger, hotter, more ductile Earth? The geology of northern Hudson Bay records the Paleoproterozoic collision between the Western Churchill and Superior plates: the 1.8Ga Trans-Hudson Orogeny (THO) and is thus an ideal study locale to address this issue. It has been suggested, primarily on the strength of traditional field geology, that the THO was comparable in scale and style to the present-day Himalayan-Karakoram-Tibet Orogen (HKTO). However, understanding of the deep crustal architecture of the THO, and how it compares to the evolving HKTO is presently lacking. Through joint inversion of teleseismic receiver functions and surface wave data, we obtain new Moho depth estimates and shear velocity models for the crust and upper mantle. Archean crust in the Rae, Hearne and Churchill domains is thin and structurally simple, with a sharp Moho; upper crustal wavespeed variations are readily attributed to post-formation events. However, the Paleoproterozoic Quebec-Baffin segment of the THO has a deeper Moho and more complex crustal structure. Our observations are strikingly similar to recent models, computed using the same methods, of the HKTO lithosphere, where deformation also extends >400km beyond the collision front. On the strength of Moho character, present-day crustal thickness, and metamorphic grade, we thus propose that southern Baffin experienced uplift of a similar magnitude and spatial extent to the Himalayas during the Paleoproterozoic Trans-Hudson Orogeny.

  12. Importance of the margin inheritance in the present-day crustal structure of the Longmen Shan range, Eastern border of the Tibetan plateau

    NASA Astrophysics Data System (ADS)

    Robert, A.; Pubellier, M.; de Sigoyer, J.; Billerot, A.; Vergne, J.

    2011-12-01

    The Longmen Shan range, located at the eastern border of the Tibetan plateau (Sichuan province, China), is characterized by one of the most important topographic gradient of the world whereas the present-day convergence recorded by GPS measurements is quite low (~3mm/yr). The mountain is also located above an abrupt 18km-high Moho step interpreted as the result of the confrontation of the thick Tibetan crust (~63km) against the resistant Yangtze craton (~45km). This peculiar crustal structure, as well as the thickening of the Tibetan crust in its eastern part, is often considerate as a result of the Cenozoic collision between India and Eurasia. This study highlights the importance of structural and thermal inheritance in the current crustal structure of this area. In fact, sedimentary records indicate that the Longmen Shan formed an abrupt passive margin from the beginning of the Paleozoic to the middle Triassic as a consequence of the opening of the Prototethys and the Paleotethys. The Longmen Shan correspond to a major paleogeographic boundary between the shallow water sediments of the Sichuan basin to the South-East and the deep sea mostly flysch-type sediments of the Songpan Garze terrane to the North West. Moreover, geochimical data indicate an important extension of the continental crust further west of the sedimentary transition. The oblique position of the Longmen Shan compared to the direction of opening is responsible of a trantensive passive margin structure as observed for the present-day vietnamian passive margin. This geometry is characterized by an abrupt decrease of the continental crust thickness associated with the sedimentary transition whereas the continent/ocean transition is located further away. We propose that the peculiar geometry of the old passive margin in the Longmen Shan is responsible for the important localization of the deformation during the 3 reactivations of the range (Triassic, Cretaceous and Late Tertiary).

  13. Present-day cosmic abundances. A comprehensive study of nearby early B-type stars and implications for stellar and Galactic evolution and interstellar dust models

    NASA Astrophysics Data System (ADS)

    Nieva, M.-F.; Przybilla, N.

    2012-03-01

    Context. Early B-type stars are ideal indicators for present-day cosmic abundances since they preserve their pristine abundances and typically do not migrate far beyond their birth environments over their short lifetimes, in contrast to older stars like the Sun. They are also unaffected by depletion onto dust grains, unlike the cold/warm interstellar medium (ISM) or H ii regions. Aims: A carefully selected sample of early B-type stars in OB associations and the field within the solar neighbourhood is studied comprehensively. Quantitative spectroscopy is used to characterise their atmospheric properties in a self-consistent way. Present-day abundances for the astrophysically most interesting chemical elements are derived in order to investigate whether a present-day cosmic abundance standard can be established. Methods: High-resolution and high-S/N FOCES, FEROS and ELODIE spectra of well-studied sharp-lined early B-type stars are analysed in non-LTE. Line-profile fits based on extensive model grids and an iterative analysis methodology are used to constrain stellar parameters and elemental abundances at high accuracy and precision. Atmospheric parameters are derived from the simultaneous establishment of independent indicators, from multiple ionization equilibria and the Stark-broadened hydrogen Balmer lines, and they are confirmed by reproduction of the stars' global spectral energy distributions. Results: Effective temperatures are constrained to 1-2% and surface gravities to less than 15% uncertainty, along with accurate rotational, micro- and macroturbulence velocities. Good agreement of the resulting spectroscopic parallaxes with those from the new reduction of the Hipparcos catalogue is obtained. Absolute values for abundances of He, C, N, O, Ne, Mg, Si and Fe are determined to better than 25% uncertainty. The synthetic spectra match the observations reliably over almost the entire visual spectral range. Three sample stars, γ Ori, o Per and θ1 Ori D, are

  14. UV-B absorbing compounds in present-day and fossil pollen, spores, cuticles, seed coats and wood: evaluation of a proxy for solar UV radiation.

    PubMed

    Rozema, J; Blokker, P; Mayoral Fuertes, M A; Broekman, R

    2009-09-01

    UV-B absorbing compounds (UACs) in present-day and fossil pollen, spores, cuticles, seed coats and wood have been evaluated as a proxy for past UV. This proxy may not only provide information on variation of stratospheric ozone and solar UV in the period preceding and during the Antarctic ozone hole (1974-present day), but also on the development and variation of the stratospheric ozone layer and solar surface UV during the evolution of life on Earth. Sporopollenin and cutin are highly resistant biopolymers, preserving well in the geological record and contain the phenolic acids p-coumaric (pCA) and ferulic acid (FA). pCA and FA represent a good perspective for a plant-based proxy for past surface UV radiation since they are induced by solar UV-B via the phenylpropanoid pathway (PPP). UV-B absorption by these monomers in the wall of pollen and spores and in cuticles may prevent damage to the cellular metabolism. Increased pCA and FA in pollen of Vicia faba exposed to enhanced UV-B was found in greenhouse experiments. Further correlative evidence comes from UV-absorbing compounds in spores from 1960-2000 comparing exposure of land plants (Lycopodium species) to solar UV before and during ozone depletion and comparing plants from Antarctica (severe ozone depletion), Arctic, and other latitudes with less or negligible ozone depletion. Wood-derived compounds guaiacyl (G), syringyl (S), and p-hydroxyphenyl (P) are produced via the PPP. The proportions of P, G, and S in the lignin differ between various plant groups (e.g. dicotyledons/monocotyledons, gymnosperms/angiosperms). It is hypothesized that this lignin composition and derived physiological and physical properties of lignin (such as tree-ring wood density) has potential as a proxy for palaeo-UV climate. However validation by exposure of trees to enhanced UV is lacking. pCA and FA also form part of cutin polymers and are found in extant and fossil Ginkgo leaf cuticles as shown by thermally-assisted hydrolysis and

  15. Differential Responses of Calcifying and Non-Calcifying Epibionts of a Brown Macroalga to Present-Day and Future Upwelling pCO2

    PubMed Central

    Saderne, Vincent; Wahl, Martin

    2013-01-01

    Seaweeds are key species of the Baltic Sea benthic ecosystems. They are the substratum of numerous fouling epibionts like bryozoans and tubeworms. Several of these epibionts bear calcified structures and could be impacted by the high pCO2 events of the late summer upwellings in the Baltic nearshores. Those events are expected to increase in strength and duration with global change and ocean acidification. If calcifying epibionts are impacted by transient acidification as driven by upwelling events, their increasing prevalence could cause a shift of the fouling communities toward fleshy species. The aim of the present study was to test the sensitivity of selected seaweed macrofoulers to transient elevation of pCO2 in their natural microenvironment, i.e. the boundary layer covering the thallus surface of brown seaweeds. Fragments of the macroalga Fucus serratus bearing an epibiotic community composed of the calcifiers Spirorbis spirorbis (Annelida) and Electra pilosa (Bryozoa) and the non-calcifier Alcyonidium hirsutum (Bryozoa) were maintained for 30 days under three pCO2 conditions: natural 460±59 µatm, present-day upwelling1193±166 µatm and future upwelling 3150±446 µatm. Only the highest pCO2 caused a significant reduction of growth rates and settlement of S. spirorbis individuals. Additionally, S. spirorbis settled juveniles exhibited enhanced calcification of 40% during daylight hours compared to dark hours, possibly reflecting a day-night alternation of an acidification-modulating effect by algal photosynthesis as opposed to an acidification-enhancing effect of algal respiration. E. pilosa colonies showed significantly increased growth rates at intermediate pCO2 (1193 µatm) but no response to higher pCO2. No effect of acidification on A. hirsutum colonies growth rates was observed. The results suggest a remarkable resistance of the algal macro-epibionts to levels of acidification occurring at present day upwellings in the Baltic. Only extreme future

  16. Present-Day Strain Transfer Across the Yakutat Collision in SW Yukon - SE Alaska: The Death of the Southern Denali Fault?

    NASA Astrophysics Data System (ADS)

    Marechal, A.; Mazzotti, S.; Ritz, J. F.; Ferry, M. A.; Freymueller, J. T.

    2014-12-01

    In SW Yukon-SE Alaska, the present-day Pacific-North America relative motion is highly oblique to the main plate boundary, resulting in strong strain-partitioning tectonics that link the Aleutian subduction to the west to Queen Charlotte transform to the south. This transition region is also the site of present-day orogeny and accretion of the Yakutat Terrane to the Northern Cordillera. Multiple datasets (GPS, geomorphology, seismicity) are integrated to characterize and quantify strain patterns, with particular emphasis on strain partitioning between strike-slip and shortening deformation. New GPS data straddling the main faults (Denali, Totschunda, Fairweather) indicate that, south of the collision corner, 95% of the Pacific-North America strike-slip motion is accommodated on the plate-boundary Fairweather Fault, leaving near-zero motion on the Denali Fault only ~100 km inboard. In contrast, the fault-perpendicular component is strongly distributed between shortening offshore, in the orogen, and inland outward motion. In the region of highest convergence obliquity, GPS data show a diffuse indentor-like deformation, with strong along-strike variations of the main fault slip rates. Preliminary results of a regional geomorphology study give further information about the Denali Fault, where previous data suggest a velocity decrease from 8 mm/yr (Matmon et al.,2006) to 4 mm/yr (Seitz et al., 2010). A high resolution DEM processed from Pleiades satellite imagery highlights a significant vertical component on the Denali Fault and very little to no strike-slip movement in its southern part. Metric-scale displacements are measured along the "inactive" part of the fault showing recent vertical deformation since the Last Glacial Maximum (~20 kyrs ago). In contrast, significant dextral offsets on post-LGM structures are measured on the southern Totschunda Fault. Ongoing datation of geomorphological markers (Be10, OSL) will give us new slip-rate estimates along the southern

  17. Human responses to eruptions of Etna (Sicily) during the late-Pre-Industrial Era and their implications for present-day disaster planning

    NASA Astrophysics Data System (ADS)

    Chester, David K.; Duncan, Angus M.; Sangster, Heather

    2012-05-01

    This paper summarises: the characteristics of eruptions that occurred between 1792/3 and 1923; the ways in which human responses evolved during the period and the lessons this history holds for the management of present-day volcanic and volcano-related disasters. People responded to eruptions at three levels: as members of a family and extended family; through the mutual support of a village or larger settlement and as citizens of the State. During the study period and with the exception of limited financial aid and preservation of law and order, the State was a minor player in responding to eruptions. Families and extended families provided shelter, accommodation and often alternative agricultural employment; whilst supportive villages communities displayed a well developed tendency to learn from experience (e.g. innovating techniques to bring land back into cultivation and avoiding the risks of phreatic activity as lava encountered water and saturated ground) and providing labour to enable household chattels and agricultural crops to be salvaged from land threatened with lava incursion. Eruptions were widely believed to be 'Acts of God', with divine punishment frequently being invoked as a primary cause of human suffering. Elaborate rituals of propitiation were performed to appease a supposed angry God, but this world-view did not produce a fatalistic attitude amongst the population preventing people from coping with disasters in a generally effective manner. Despite present day emergencies being handled by the State and its agencies, some features of nineteenth century responses remain in evidence, including salvaging all that may be easily removed from a building and/or agricultural holding, and explanations of disaster which are theistic in character. Lessons from eruptions that occurred between 1792/3 to 1923 are that the former should be encouraged, whilst the latter does not prevent people acting to preserve life and property or obeying the authorities

  18. UV-B absorbing compounds in present-day and fossil pollen, spores, cuticles, seed coats and wood: evaluation of a proxy for solar UV radiation.

    PubMed

    Rozema, J; Blokker, P; Mayoral Fuertes, M A; Broekman, R

    2009-09-01

    UV-B absorbing compounds (UACs) in present-day and fossil pollen, spores, cuticles, seed coats and wood have been evaluated as a proxy for past UV. This proxy may not only provide information on variation of stratospheric ozone and solar UV in the period preceding and during the Antarctic ozone hole (1974-present day), but also on the development and variation of the stratospheric ozone layer and solar surface UV during the evolution of life on Earth. Sporopollenin and cutin are highly resistant biopolymers, preserving well in the geological record and contain the phenolic acids p-coumaric (pCA) and ferulic acid (FA). pCA and FA represent a good perspective for a plant-based proxy for past surface UV radiation since they are induced by solar UV-B via the phenylpropanoid pathway (PPP). UV-B absorption by these monomers in the wall of pollen and spores and in cuticles may prevent damage to the cellular metabolism. Increased pCA and FA in pollen of Vicia faba exposed to enhanced UV-B was found in greenhouse experiments. Further correlative evidence comes from UV-absorbing compounds in spores from 1960-2000 comparing exposure of land plants (Lycopodium species) to solar UV before and during ozone depletion and comparing plants from Antarctica (severe ozone depletion), Arctic, and other latitudes with less or negligible ozone depletion. Wood-derived compounds guaiacyl (G), syringyl (S), and p-hydroxyphenyl (P) are produced via the PPP. The proportions of P, G, and S in the lignin differ between various plant groups (e.g. dicotyledons/monocotyledons, gymnosperms/angiosperms). It is hypothesized that this lignin composition and derived physiological and physical properties of lignin (such as tree-ring wood density) has potential as a proxy for palaeo-UV climate. However validation by exposure of trees to enhanced UV is lacking. pCA and FA also form part of cutin polymers and are found in extant and fossil Ginkgo leaf cuticles as shown by thermally-assisted hydrolysis and

  19. Differential responses of calcifying and non-calcifying epibionts of a brown macroalga to present-day and future upwelling pCO2.

    PubMed

    Saderne, Vincent; Wahl, Martin

    2013-01-01

    Seaweeds are key species of the Baltic Sea benthic ecosystems. They are the substratum of numerous fouling epibionts like bryozoans and tubeworms. Several of these epibionts bear calcified structures and could be impacted by the high pCO2 events of the late summer upwellings in the Baltic nearshores. Those events are expected to increase in strength and duration with global change and ocean acidification. If calcifying epibionts are impacted by transient acidification as driven by upwelling events, their increasing prevalence could cause a shift of the fouling communities toward fleshy species. The aim of the present study was to test the sensitivity of selected seaweed macrofoulers to transient elevation of pCO2 in their natural microenvironment, i.e. the boundary layer covering the thallus surface of brown seaweeds. Fragments of the macroalga Fucus serratus bearing an epibiotic community composed of the calcifiers Spirorbis spirorbis (Annelida) and Electra pilosa (Bryozoa) and the non-calcifier Alcyonidium hirsutum (Bryozoa) were maintained for 30 days under three pCO2 conditions: natural 460 ± 59 µatm, present-day upwelling1193 ± 166 µatm and future upwelling 3150 ± 446 µatm. Only the highest pCO2 caused a significant reduction of growth rates and settlement of S. spirorbis individuals. Additionally, S. spirorbis settled juveniles exhibited enhanced calcification of 40% during daylight hours compared to dark hours, possibly reflecting a day-night alternation of an acidification-modulating effect by algal photosynthesis as opposed to an acidification-enhancing effect of algal respiration. E. pilosa colonies showed significantly increased growth rates at intermediate pCO2 (1193 µatm) but no response to higher pCO2. No effect of acidification on A. hirsutum colonies growth rates was observed. The results suggest a remarkable resistance of the algal macro-epibionts to levels of acidification occurring at present day upwellings in the Baltic. Only extreme

  20. Effects of submarine groundwater discharge on the present-day extent of relict submarine permafrost and gas hydrate stability on the Beaufort Sea continental shelf

    NASA Astrophysics Data System (ADS)

    Frederick, J. M.; Buffett, B. A.

    2015-03-01

    We investigate the role of submarine groundwater discharge on the offshore temperature and salinity field and its effect on the present-day extent of submarine permafrost and gas hydrate stability on the North American Beaufort Shelf with a two-dimensional numerical model based on the finite volume method. This study finds that submarine groundwater discharge can play a large role in submarine permafrost evolution and gas hydrate stability, suggesting that local hydrology may control the evolution of submarine permafrost as strongly as does sea level or paleoclimatic conditions. Submarine permafrost evolution shows transient behavior over potentially long time scales (e.g., several glacial cycles) before a balance of density- and pressure-driven flows is established with the permeability variations imposed by the overlying permafrost layer. The "detectable" offshore permafrost extent is related to the quasi-stationary location of the saltwater-freshwater transition. Larger values of submarine groundwater discharge allow permafrost to extend farther offshore because fresh pore water preserves relict ice. Therefore, differences in the permafrost extent at locations that share similar paleoclimatic history may be explained in part by differences in the local hydrology. Gas hydrate stability on the North American Beaufort Shelf may be more widespread than currently thought because low-ice saturation, highly degraded submarine permafrost likely exists beyond the boundary detectable by common geophysical methods.

  1. Sulfur Dioxide and the Production of Sulfuric Acid on Present-Day and Early Mars: Implications for the Lack of Detected Carbonates on the Surface

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.; Summers, Michael E.

    2008-01-01

    In the early history of Mars, volcanic activity associated with the formation of the Tharsis ridge produced a very large amount of atmospheric SO2--on the order of a bar of atmospheric SO2. In the present-day atmosphere of Mars, the lifetime of SO2 is relatively short with a lifetime of less than a day. The short lifetime of SO2 in the present Mars atmosphere makes the production of significant levels of H2SO4 very difficult since the SO2 may be destroyed by various chemical and photochemical processes before the SO2 can be converted to H2SO4. However, photochemical calculations performed and described here, indicate that enhanced atmospheric levels of CO2 in the early atmosphere of Mars resulted in a significantly enhanced atmospheric lifetime for SO2 up to several years. With a significantly enhanced atmospheric lifetime, SO2 could readily form large amounts of H2SO4, which precipitated out of the atmosphere in the form of droplets. The precipitated H2SO4 then reacted with potential surface carbonates, destroying the carbonates and resulting in the abundant and widespread distribution of sulfates on the surface of Mars as detected by recent Mars missions.

  2. Laser-assisted cavity preparation and adhesion to erbium-lased tooth structure: part 2. present-day adhesion to erbium-lased tooth structure in permanent teeth.

    PubMed

    De Moor, Roeland Jozef Gentil; Delme, Katleen Ilse Maria

    2010-04-01

    With the introduction of the Er:YAG laser, it has become possible to remove enamel and dentin more effectively and efficiently than with other lasers. Thermal damage is reduced, especially in conjunction with water spray. Since FDA (Federal Drug Administration) approval of the Er:YAG laser in 1997--for caries removal, cavity preparation and conditioning of tooth substance - there have been many reports on the use of this technique in combination with composite resins. Moreover, cavity pretreatment with Er:YAG laser (laser etching) has been proposed as an alternative to acid etching of enamel and dentin. Reports evaluating the adhesion of glass-ionomer cements to Er:YAG-lased tooth substance are scarce. This article reviews the literature regarding adhesion and sealing efficacy using different (pre)treatment protocols in association with Er:YAG laser preparation. Recent research has shown that lasing of enamel and dentin may result in surface and subsurface alterations that have negative effects on both adhesion and seal. It is concluded that at present, it is advisable to respect the conventional pretreatment procedures as needed for the respective adhesive materials. Although the majority of present day reports show that microleakage and bond strength are negatively influenced by laser (pre)treatment (compared with conventional preparation), there is ongoing discussion of how adhesion is best achieved on Er:YAG-lased surfaces.

  3. Investigations of potential microbial methanogenic and carbon monoxide utilization pathways in ultra-basic reducing springs associated with present-day continental serpentinization: the Tablelands, NL, CAN

    PubMed Central

    Morrill, Penny L.; Brazelton, William J.; Kohl, Lukas; Rietze, Amanda; Miles, Sarah M.; Kavanagh, Heidi; Schrenk, Matthew O.; Ziegler, Susan E.; Lang, Susan Q.

    2014-01-01

    Ultra-basic reducing springs at continental sites of serpentinization act as portals into the biogeochemistry of a subsurface environment with H2 and CH4 present. Very little, however, is known about the carbon substrate utilization, energy sources, and metabolic pathways of the microorganisms that live in this ultra-basic environment. The potential for microbial methanogenesis with bicarbonate, formate, acetate, and propionate precursors and carbon monoxide (CO) utilization pathways were tested in laboratory experiments by adding substrates to water and sediment from the Tablelands, NL, CAD, a site of present-day continental serpentinization. Microbial methanogenesis was not observed after bicarbonate, formate, acetate, or propionate addition. CO was consumed in the live experiments but not in the killed controls and the residual CO in the live experiments became enriched in 13C. The average isotopic enrichment factor resulting from this microbial utilization of CO was estimated to be 11.2 ± 0.2‰. Phospholipid fatty acid concentrations and δ13C values suggest limited incorporation of carbon from CO into microbial lipids. This indicates that in our experiments, CO was used primarily as an energy source, but not for biomass growth. Environmental DNA sequencing of spring fluids collected at the same time as the addition experiments yielded a large proportion of Hydrogenophaga-related sequences, which is consistent with previous metagenomic data indicating the potential for these taxa to utilize CO. PMID:25431571

  4. Human reponses to historical eruptions of Etna (Sicily) from 1600 to present and their implications for present-day disaster planning

    NASA Astrophysics Data System (ADS)

    Sangster, H.; Chester, D. K.; Duncan, A. M.

    2012-04-01

    Mount Etna in northeastern Sicily (Italy) rises to over 3000 m, covers an area of ca.1750 km2 and is the most active volcano in Europe. Observations of Etna by literate observers stretch back to the classical era and one of the earliest references to an eruption of Etna was by Pindar in his Pythian Odes, to the event of ca. 474-479 B.C. The history of its activity has been reconstructed by scholars up to the present day and records of eruptions are reasonably complete from the early fifteenth century, reliable from 1669, and document the threats and destruction to human settlements and livelihoods. Effusive and explosive activity has occurred continually throughout the historical period and eruptions of Mount Etna have presented numerous eruption styles, from persistent central crater activity, to periodic flank eruptions. From 1600 to 1669 the activity of Etna was characterised by a high volumetric output of lava with a mean eruption rate of 1.19 m3s-1, this was followed by a pause from flank eruptions and the re-establishment of significant activity from the middle of the eighteenth century. After 1750 the output of lava by flank eruptions was lower than in the previous century, with the mean eruption rate falling to 0.18 m3s-1. This paper summarises: the characteristics of the eruptions that occurred between the period of 1600 to present; the particularities of the societal responses over time and the role of the authorities; and, the important lessons this history holds for the management of present-day civil defence planning in the region. People responded to the eruptions at three levels: as members of a family and extended family; as members of a community and, as citizens of the State. The State, however, was a minor player in responding to these eruptions until the early nineteenth century as the State then became more involved in each successive eruption as the responses moved to a more industrial nature rather than pre-industrial. Today emergencies are

  5. [Embolism of the aortic bifurcation and major arteries of limbs: lessons of the past and present-day trends in solving the problem concerned].

    PubMed

    Mel'nikov, M V; Barsukov, A E; Apresian, A Iu; Isaulov, O V

    2013-01-01

    The works deals with a retrospective analysis of the medical records of the Clinic of General Surgery of the North-West State Medical University named after I.I. Mechnikov on treatment of patients presenting with embolism of the aorta and major arteries over 40 years. All in all, over the period from 1971 to 2010 a total of 3,110 patients with embolism of the aorta and major arteries underwent consultations and were operated on. To the present-day trends in surgery of embologenic arterial obstruction one should first of all refer a decrease in the number of patients with embolism of the aorta and major arteries of the limbs, which may be related to achievement in modern cardiology and cardiosurgery in treatment of patients with cardiovascular diseases - potential sources of arterial embolism. Besides, there occurred considerable changes in the structure of embologenic diseases, in favour of an increased number of people suffering from CAD, which to e certain degree modified the incidence of lesions of various vascular basins. Thus, the number of embolisms of proximal portions of the vascular bed decreased considerably. This is largely related to a decrease in the number of patients presenting with decompensated ischaemia of extremities. 86.9% of patients were subjected to emergency operations. An increased number of people with atherosclerosis of peripheral arteries required widening of indications for performing reconstructive-and-plastic operative interventions. Experience of the Clinic shows that a timely performed revascularizing operation, including a reconstructive on, application of modern methods of prevention of ischaemic syndrome, carrying out comprehensive rehabilitation measures in the postoperative period made it possible to considerably improve the immediate results of treatment. While during the first 20 years a total lethality rate amounted to 18.8% with the postoperative one equalling 17.1%, these parameters over the past 10 years were 8.8% and 6

  6. Evaluation of Preindustrial to Present-day Black Carbon and its Albedo Forcing from Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)

    SciTech Connect

    Lee, Y. H.; Lamarque, J.-F.; Flanner, M. G.; Jiao, C.; Shindell, Drew; Berntsen, T.; Bisiauxs, M.; Cao, J.; Collins, W. J.; Curran, M.; Edwards, R.; Faluvegi, G.; Ghan, Steven J.; Horowitz, L.; McConnell, J.R.; Ming, J.; Myhre, G.; Nagashima, T.; Naik, Vaishali; Rumbold, S.; Skeie, R. B.; Sudo, K.; Takemura, T.; Thevenon, F.; Xu, B.; Yoon, Jin-Ho

    2013-03-05

    As a part of the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), we evaluate the historical black carbon (BC) aerosols simulated by 8 ACCMIP models against the observations including 12 ice core records, a long-term surface mass concentrations and recent Arctic BC snowpack measurements. We also estimate BC albedo forcing by performing additional simulations using the NCAR Community Land and Sea-Ice model 4 with prescribed meteorology from 1996-2000, which includes the SNICAR BC-snow model. We evaluated the vertical profile of BC snow concentrations from these offline simulations to using recent BC snowpack measurements. Despite using the same BC emissions, global BC burden differs by approximately a factor of 3 among models due to the differences in aerosol removal parameterizations and simulated meteorology among models; 34 Gg to 103 Gg in 1850 and 82 Gg to 315 Gg in 2000. However,models agree well on 2.5~3 times increase in the global BC burden from preindustrial to present-day, which matches with the 2.5 times increase in BC emissions. We find a large model diversity at both NH and SH high latitude regions for BC burden and at SH high latitude regions for deposition fluxes. The ACCMIP simulations match the observed BC mass concentrations well in Europe and North America except at Jungfrauch and Ispra. However, the models fail to capture the Arctic BC seasonality due tosevere underestimations during winter and spring. Compared to recent snowpack measurements, the simulated vertically resolved BC snow concentrations are, on average, within a factor of 2-3 of observations except for Greenland and Arctic Ocean. However, model and observation differ widely due to missing interannual variations in emissions and possibly due to the choice of the prescribed meteorology period (i.e., 1996-2000).

  7. A new method to estimate air-quality levels using a synoptic-regression approach. Part I: Present-day O 3 and PM 10 analysis

    NASA Astrophysics Data System (ADS)

    Demuzere, Matthias; van Lipzig, Nicole P. M.

    2010-03-01

    In order to make projections for future air-quality levels, a robust methodology is needed that succeeds in reconstructing present-day air-quality levels. At present, climate projections for meteorological variables are available from Atmospheric-Ocean Coupled Global Climate Models (AOGCMs) but the temporal and spatial resolution is insufficient for air-quality assessment. Therefore, a variety of methods are tested in this paper in their ability to hindcast maximum 8 hourly levels of O 3 and daily mean PM 10 from observed meteorological data. The methods are based on a multiple linear regression technique combined with the automated Lamb weather classification. Moreover, we studied whether the above-mentioned multiple regression analysis still holds when driven by operational ECMWF (European Center for Medium-Range Weather Forecast) meteorological data. The main results show that a weather type classification prior to the regression analysis is superior to a simple linear regression approach. In contrast to PM 10 downscaling, seasonal characteristics should be taken into account during the downscaling of O 3 time series. Apart from a lower explained variance due to intrinsic limitations of the regression approach itself, a lower variability of the meteorological predictors (resolution effect) and model deficiencies, this synoptic-regression-based tool is generally able to reproduce the relevant statistical properties of the observed O 3 distributions important in terms of European air quality Directives and air quality mitigation strategies. For PM 10, the situation is different as the approach using only meteorology data was found to be insufficient to explain the observed PM 10 variability using the meteorological variables considered in this study.

  8. Estimating present day extreme water level exceedance probabilities around the coastline of Australia: tides, extra-tropical storm surges and mean sea level

    NASA Astrophysics Data System (ADS)

    Haigh, Ivan D.; Wijeratne, E. M. S.; MacPherson, Leigh R.; Pattiaratchi, Charitha B.; Mason, Matthew S.; Crompton, Ryan P.; George, Steve

    2014-01-01

    The occurrence of extreme water levels along low-lying, highly populated and/or developed coastlines can lead to considerable loss of life and billions of dollars of damage to coastal infrastructure. Therefore it is vitally important that the exceedance probabilities of extreme water levels are accurately evaluated to inform risk-based flood management, engineering and future land-use planning. This ensures the risk of catastrophic structural failures due to under-design or expensive wastes due to over-design are minimised. This paper estimates for the first time present day extreme water level exceedence probabilities around the whole coastline of Australia. A high-resolution depth averaged hydrodynamic model has been configured for the Australian continental shelf region and has been forced with tidal levels from a global tidal model and meteorological fields from a global reanalysis to generate a 61-year hindcast of water levels. Output from this model has been successfully validated against measurements from 30 tide gauge sites. At each numeric coastal grid point, extreme value distributions have been fitted to the derived time series of annual maxima and the several largest water levels each year to estimate exceedence probabilities. This provides a reliable estimate of water level probabilities around southern Australia; a region mainly impacted by extra-tropical cyclones. However, as the meteorological forcing used only weakly includes the effects of tropical cyclones, extreme water level probabilities are underestimated around the western, northern and north-eastern Australian coastline. In a companion paper we build on the work presented here and more accurately include tropical cyclone-induced surges in the estimation of extreme water level. The multi-decadal hindcast generated here has been used primarily to estimate extreme water level exceedance probabilities but could be used more widely in the future for a variety of other research and practical

  9. Interactive effects of ocean acidification and warming on coral reef associated epilithic algal communities under past, present-day and future ocean conditions

    NASA Astrophysics Data System (ADS)

    Vogel, N.; Cantin, N. E.; Strahl, J.; Kaniewska, P.; Bay, L.; Wild, C.; Uthicke, S.

    2016-06-01

    Epilithic algal communities play critical ecological roles on coral reefs, but their response to individual and interactive effects of ocean warming (OW) and ocean acidification (OA) is still largely unknown. We investigated growth, photosynthesis and calcification of early epilithic algal community assemblages exposed for 6 months to four temperature profiles (-1.1, ±0.0, +0.9, +1.6 °C) that were crossed with four carbon dioxide partial pressure (pCO2) levels (360, 440, 650, 940 µatm), under flow-through conditions and natural light regimes. Additionally, we compared the cover of heavily calcified crustose coralline algae (CCA) and lightly calcified red algae of the genus Peyssonnelia among treatments. Increase in cover of epilithic communities showed optima under moderately elevated temperatures and present pCO2, while cover strongly decreased under high temperatures and high-pCO2 conditions, particularly due to decreasing cover of CCA. Similarly, community calcification rates were strongly decreased at high pCO2 under both measured temperatures. While final cover of CCA decreased under high temperature and pCO2 (additive negative effects), cover of Peyssonnelia spp. increased at high compared to annual average and moderately elevated temperatures. Thus, cover of Peyssonnelia spp. increased in treatment combinations with less CCA, which was supported by a significant negative correlation between organism groups. The different susceptibility to stressors most likely derived from a different calcification intensity and/or mineral. Notably, growth of the epilithic communities and final cover of CCA were strongly decreased under reduced-pCO2 conditions compared to the present. Thus, CCA may have acclimatized from past to present-day pCO2 conditions, and changes in carbonate chemistry, regardless in which direction, negatively affect them. However, if epilithic organisms cannot further acclimatize to OW and OA, the interacting effects of both factors may change

  10. Paleontological records indicate the occurrence of open woodlands in a dry inland climate at the present-day Arctic coast in western Beringia during the Last Interglacial

    NASA Astrophysics Data System (ADS)

    Kienast, Frank; Wetterich, Sebastian; Kuzmina, Svetlana; Schirrmeister, Lutz; Andreev, Andrei A.; Tarasov, Pavel; Nazarova, Larisa; Kossler, Annette; Frolova, Larisa; Kunitsky, Viktor V.

    2011-08-01

    Permafrost records, accessible at outcrops along the coast of Oyogos Yar at the Dmitry Laptev Strait, NE-Siberia, provide unique insights into the environmental history of Western Beringia during the Last Interglacial. The remains of terrestrial and freshwater organisms, including plants, coleopterans, chironomids, cladocerans, ostracods and molluscs, have been preserved in the frozen deposits of a shallow paleo-lake and indicate a boreal climate at the present-day arctic mainland coast during the Last Interglacial. Terrestrial beetle and plant remains suggest the former existence of open forest-tundra with larch ( Larix dahurica), tree alder ( Alnus incana), birch and alder shrubs ( Duschekia fruticosa, Betula fruticosa, Betula divaricata, Betula nana), interspersed with patches of steppe and meadows. Consequently, the tree line was shifted to at least 270 km north of its current position. Aquatic organisms, such as chironomids, cladocerans, ostracods, molluscs and hydrophytes, indicate the formation of a shallow lake as the result of thermokarst processes. Steppe plants and beetles suggest low net precipitation. Littoral pioneer plants and chironomids indicate intense lake level fluctuations due to high evaporation. Many of the organisms are thermophilous, indicating a mean air temperature of the warmest month that was greater than 13 °C, which is above the minimum requirements for tree growth. These temperatures are in contrast to the modern values of less than 4 °C in the study area. The terrestrial and freshwater organism remains were found at a coastal exposure that was only 3.5 m above sea level and in a position where they should have been under sea during the Last Interglacial when the global sea level was 6-10 m higher than the current levels. The results suggest that during the last warm stage, the site was inland, and its modern coastal situation is the result of tectonic subsidence.

  11. Little Ice Age versus Present Day: Comparison of Temperature, Precipitation and Seasonality in Speleothem Records from the Han-sur-Lesse Cave, Belgium.

    NASA Astrophysics Data System (ADS)

    Vansteenberge, S.; Van Opdenbosch, J.; Van Rampelbergh, M.; Verheyden, S.; Keppens, E.; Cheng, H.; Edwards, R. L.; Claeys, P. F.

    2015-12-01

    The Proserpine stalagmite is a 2 m large, tabular-shaped speleothem located in the Han-sur-Lesse cave in Belgium. The speleothem formed over the last 1000 years and is still growing. High-accuracy U/Th datings have indicated exceptionally high growth-rates of up to 2 mm per year. This, together with a well expressed annual layering, makes the Proserpine stalagmite an ideal candidate for high-resolution paleoclimate reconstructions of the last millennium. Previous work, including over 10 years of cave monitoring, has already learned us how short-term, i.e. decadal to seasonal, climate variations are incorporated within speleothem calcite from the Han-sur-Lesse cave system. It has been shown that δ18O and δ13C stable isotopes and trace element proxies of recently formed calcite reflect seasonal variations in temperature and precipitation of the near-cave environment (Verheyden et al, 2008; Van Rampelbergh et al., 2014). Now, this knowledge was used to infer local climate parameters further back in time to the period of +/- 1620-1630 CE, corresponding to one of the cold peaks within the Little Ice Age. Speleothem calcite was sampled at sub-annual resolution, with approximately 11 samples per year, for stable isotope analysis. LA-ICP-MS and µXRF analyses resulted in time series of trace elements. Preliminary results indicate a well expressed seasonal signal in δ13C and trace element composition but a multi-annual to decadal trend in δ18O. This combined proxy study eventually enables comparison of the expression of seasonality and longer term climate variations between a Little Ice Age cold peak and Present Day. References: Verheyden, S. et al., 2008, Monitoring climatological, hydrological and geochemical parameters in the Père Noël cave (Belgium): implication for the interpretation of speleothem isotopic and geochemical time-series. International Journal of Speleology, 37(3), 221-234. Van Rampelbergh, M. et al., 2014, Seasonal variations recorded in cave

  12. Grainsize Patterns and Bed Evolution of the Rhone River (France): A Present-day Snapshot Following a Century and a Half of Human Modifications

    NASA Astrophysics Data System (ADS)

    Michal, T.; Parrot, E.; Piegay, H.

    2014-12-01

    Over the past 150 years the Rhône River has been heavily altered by human infrastructures. The first wave (1860 - 1930) of modifications consisted of dikes and groynes designed to narrow the channel and promote incision in order to facilitate navigation. A second period (1948 - 1986) involved the construction of a series of canals and dams for hydroelectricity production. These works bypass multiple reaches of the original channel and drastically reduce the discharge and sediment load reaching them. A comprehensive study underway is aimed at describing the present-day morphology of the Rhone along its 512 km length from its source at Lake Geneva to its sink at the Mediterranean Sea and quantifying the role of management works in the evolution to its current state. Grainsize distributions and armour ratios were determined using a combination of Wolman counts on bars and in shallow channels and dredge samples collected from a boat in navigable reaches. Long profiles were constructed from historical bathymetric maps and bathymetric data collected between 1950 - 2010. Differential long profiles highlighting changes in bed elevation due to sediment storage and erosion were analyzed for three different periods: post-channelization, post-dam construction, and a recent period of major floods. Results show a complex discontinuous pattern in grainsize associated with hydraulic discontinuities imposed by dams. The D50 for bypass reaches is 45 mm compared to a D50 of 34 mm in the non-bypass reaches. The lower D50 as well as a finer tailed distribution in non-bypass reaches reflects fining associated with storage upstream of dams. Armour ratios are on average around 2 but are notably higher for reaches in the middle section of the Rhone. The average incision rate was 1.8 cm/yr for the period of post-channelization and 1.2 cm/yr following dam construction, suggesting the post-dam Rhone was already partially armoured due to incision associated with channelization preceding dam

  13. Present-day stress analysis of the St. Lawrence Lowlands sedimentary basin (Canada) and implications for caprock integrity during CO2 injection operations

    NASA Astrophysics Data System (ADS)

    Konstantinovskaya, E.; Malo, M.; Castillo, D. A.

    2012-01-01

    A geomechanical analysis of the St. Lawrence Lowlands sedimentary basin is important to reliably estimate the maximum sustainable fluid pressures for CO2 injection that will not reactivate pre-existing faults in the caprock thereby inducing a breeched CO2 reservoir. This requires the determination of prevailing stresses (orientations and magnitudes), fault and fractures geometries and rock strengths. The average maximum horizontal stress orientation (SHmax) is estimated N59°E ± 20° in the St. Lawrence Lowlands. The stress orientations were obtained from stress-induced wellbore breakouts inferred from four-arm dipmeter caliper data in 17 wells. These wellbore failure features are confined to Paleozoic lithological units of the St. Lawrence Platform succession and frontal thrusts of the Quebec Appalachians at depths from 250 m to 4 km. Our results are consistent with the regional NE-SW SHmax stress orientation trend that is generally observed in eastern Canada and the U.S. The stresses/pressure gradients estimated for the St. Lawrence Lowlands (depths < 4 km) are: Shmin 20.5 ± 3 kPa/m, Sv 25.6 kPa/m, SHmax 40 ± 7.5 kPa/m, pore pressure Pp 9.8 kPa/m indicating a strike-slip stress regime Shmin < Sv < SHmax. The high-angle NE-SW regional faults and fractures in the Paleozoic sedimentary succession and the Grenvillian basement are oblique to the SHmax stress orientations (10° to 36°) and could be reactivated (slip tendency 0.34 to 0.58) under the present-day stress field if fluid pressures exceeded the critical threshold. Further refinement of regional geomechanical model is required to estimate the maximum sustainable injection pressure necessary for shear reactivation along the regional faults. The regional pore pressure-stress coupling ratio under assumed parameters is about 0.5-0.65 and may contribute to reduce the risk of shear reactivation of faults and fractures. The maximum sustainable Pp that would not cause opening of vertical tensile fractures during

  14. A critical evaluation of present-day and future surface ozone as simulated by global chemistry-climate models in the Atmospheric Chemistry & Climate Model Intercomparison Project (ACCMIP)

    NASA Astrophysics Data System (ADS)

    Schnell, J.; Prather, M. J.

    2014-12-01

    In evaluating a future scenario for air quality, one can identify four major causal factors: (1) global emissions that alter atmospheric composition and thence baseline levels of surface ozone (O3); (2) global changes in climate that also alter these baselines (e.g., temperature, water vapor); (3) climate-driven changes in the meteorological regimes of polluted regions that lead to air quality extreme (AQX) episodes; and (4) changes in the efficacy of local emissions to produce pollution within a governance region. While these factors are all part of a coupled system, a model that combines all would be difficult to verify. Thus an assessment approach would be to evaluate each factor separately using observations and an ensemble of models. In this study, we focus on factor (3), evaluating the ability of the models in the Atmospheric Chemistry & Climate Model Intercomparison Project (ACCMIP) to reproduce the observed present-day climatology (e.g. diurnal/seasonal cycles, AQX episode size) of surface O3 in North America (NA) and Europe (EU). We then characterize future changes within these domains as well as south Asia (SA) for two experiments of RCP8.5 climate, one with O3 precursor emissions representative of the 2100s (RCP8.5) and one representative of the 2000s (Cl2100Em2000). We find that most models simulate the observed climatology well, albeit biased high over the range of each domain's probability distribution (Fig. 1). For RCP8.5, the ensemble mean shows an increase of ~10% in the mean annual maximum daily 8-h average (MDA8) over all domains, with the largest changes in winter months. For Cl2100Em2000, NA shows a small increase (+1%) in annual mean MDA8 while EU and SA show small decreases (-2% and -3%, respectively). Also for RCP8.5, most models show decreases in the mean size (S) and mean duration (D) of AQX episodes in EU (S = -28%, D = -17%) and increases in SA (+54%, +15%). The ensemble mean shows decreases in D (-7%) and increases in S (+21%) in NA

  15. Present-day stress tensors along the southern Caribbean plate boundary zone from inversion of focal mechanism solutions: A successful trial

    NASA Astrophysics Data System (ADS)

    Audemard M., Franck A.; Castilla, Raymi

    2016-11-01

    This paper presents a compilation of 16 present-day stress tensors along the southern Caribbean plate boundary zone (PBZ), and particularly in western and along northern Venezuela. As a trial, these new stress tensors along PBZ have been calculated from inversion of 125 focal mechanism solutions (FMS) by applying the Angelier & Mechler's dihedral method, which were originally gathered by the first author and published in 2005. These new tensors are compared to those 59 tensors inverted from fault-slip data measured only in Plio-Quaternary sedimentary rocks, compiled in Audemard et al. (2005), which were originally calculated by several researchers through the inversion methods developed by Angelier and Mechler or Etchecopar et al. The two sets of stress tensors, one derived from geological data and the other one from seismological data, compare very well throughout the PBZ in terms of both stress orientation and shape of the stress tensor. This region is characterized by a compressive strike-slip (transpressional senso lato), occasionally compressional, regime from the southern Mérida Andes on the southwest to the gulf of Paria in the east. Significant changes in direction of the maximum horizontal stress (σH = σ1) can be established along it though. The σ1 direction varies progressively from nearly east-west in the southern Andes (SW Venezuela) to between NW-SE and NNW-SSE in northwestern Venezuela; this direction remaining constant across northern Venezuela, from Colombia to Trinidad. In addition, the σV defined by inversion of focal mechanisms or by the shape of the stress ellipsoid derived from the Etchecopar et al.'s method better characterize whether the stress regime is transpressional or compressional, or even very rarely trantensional at local scale. The orientation and space variation of this regional stress field in western Venezuela results from the addition of the two major neighbouring interplate maximum horizontal stress orientations (

  16. Evaluation and intercomparison of downscaled daily precipitation indices over Japan in present-day climate: Strengths and weaknesses of dynamical and bias correction-type statistical downscaling methods

    NASA Astrophysics Data System (ADS)

    Iizumi, Toshichika; Nishimori, Motoki; Dairaku, Koji; Adachi, Sachiho A.; Yokozawa, Masayuki

    2011-01-01

    In this study, we evaluate the accuracy of four regional climate models (NHRCM, NRAMS, TRAMS, and TWRF) and one bias correction-type statistical model (CDFDM) for daily precipitation indices under the present-day climate (1985-2004) over Japan on a 20 km grid interval. The evaluated indices are (1) mean precipitation, (2) number of days with precipitation ≥1 mm/d (corresponds to number of wet days), (3) mean amount per wet day, (4) 90th percentile of daily precipitation, and (5) number of days with precipitation ≥90th percentile of daily precipitation. The boundary conditions of the dynamical models and the predictors of the statistical model are given from the single reanalysis data, i.e., JRA25. Both types of models successfully improved the accuracy of the indices relative to the reanalysis data in terms of bias, seasonal cycle, geographical pattern, cumulative distribution function of wet-day amount, and interannual variation pattern. In most aspects, NHRCM is the best model of all indices. Through the intercomparison between the dynamical and statistical models, respective strengths and weaknesses emerged. Briefly, (1) many dynamical models simulate too many wet days with a small amount of precipitation in humid climate zones, such as summer in Japan, relative to the statistical model, unless the cumulus convection scheme improved for such a condition is incorporated; (2) a few dynamical models can derive a better high-order percentile of daily precipitation (e.g., 90th percentile) than the statistical model; (3) both the dynamical and statistical models are still insufficient in the representation of the interannual variation pattern of the number of days with precipitation ≥90th percentile of daily precipitation; (4) the statistical model is comparable to the dynamical models in the long-term mean geographical pattern of the indices even on a 20 km grid interval if a dense observation network is applicable; (5) the statistical model is less accurate

  17. Aerosol Direct, Indirect, Semidirect, and Surface Albedo Effects from Sector Contributions Based on the IPCC AR5 Emissions for Preindustrial and Present-day Conditions

    NASA Technical Reports Server (NTRS)

    Bauer, Susanne E.; Menon, Surabi

    2012-01-01

    The anthropogenic increase in aerosol concentrations since preindustrial times and its net cooling effect on the atmosphere is thought to mask some of the greenhouse gas-induced warming. Although the overall effect of aerosols on solar radiation and clouds is most certainly negative, some individual forcing agents and feedbacks have positive forcing effects. Recent studies have tried to identify some of those positive forcing agents and their individual emission sectors, with the hope that mitigation policies could be developed to target those emitters. Understanding the net effect of multisource emitting sectors and the involved cloud feedbacks is very challenging, and this paper will clarify forcing and feedback effects by separating direct, indirect, semidirect and surface albedo effects due to aerosols. To this end, we apply the Goddard Institute for Space Studies climate model including detailed aerosol microphysics to examine aerosol impacts on climate by isolating single emission sector contributions as given by the Coupled Model Intercomparison Project Phase 5 (CMIP5) emission data sets developed for Intergovernmental Panel on Climate Change (IPCC) AR5. For the modeled past 150 years, using the climate model and emissions from preindustrial times to present-day, the total global annual mean aerosol radiative forcing is -0.6 W/m(exp 2), with the largest contribution from the direct effect (-0.5 W/m(exp 2)). Aerosol-induced changes on cloud cover often depends on cloud type and geographical region. The indirect (includes only the cloud albedo effect with -0.17 W/m(exp 2)) and semidirect effects (-0.10 W/m(exp 2)) can be isolated on a regional scale, and they often have opposing forcing effects, leading to overall small forcing effects on a global scale. Although the surface albedo effects from aerosols are small (0.016 W/m(exp 2)), triggered feedbacks on top of the atmosphere (TOA) radiative forcing can be 10 times larger. Our results point out that each

  18. Evaluation of preindustrial to present-day black carbon and its albedo forcing from Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)

    NASA Technical Reports Server (NTRS)

    Lee, Y. H.; Lamarque, J.-F.; Flanner, M. G.; Jiao, C.; Shindell, D. T.; Bernsten, T.; Bisiaux, M. M.; Cao, J.; Collins, W. J.; Curran, M.; Edwards, R.; Faluvegi, G.; Ghan, S.; Horowitz, L. W.; McConnell, J. R.; Ming, J.; Myhre, G.; Nagashima, T.; Naik, V.; Rumbold, S. T.; Skeie, R. B.; Sudo, K.; Takemura, T.; Thevenon, F.; Xu, B.; Yoon, J.-H.

    2013-01-01

    As part of the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), we evaluate the historical black carbon (BC) aerosols simulated by 8 ACCMIP models against observations including 12 ice core records, long-term surface mass concentrations, and recent Arctic BC snowpack measurements. We also estimate BC albedo forcing by performing additional simulations using offline models with prescribed meteorology from 1996-2000. We evaluate the vertical profile of BC snow concentrations from these offline simulations using the recent BC snowpack measurements. Despite using the same BC emissions, the global BC burden differs by approximately a factor of 3 among models due to differences in aerosol removal parameterizations and simulated meteorology: 34 Gg to 103 Gg in 1850 and 82 Gg to 315 Gg in 2000. However, the global BC burden from preindustrial to present-day increases by 2.5-3 times with little variation among models, roughly matching the 2.5-fold increase in total BC emissions during the same period.We find a large divergence among models at both Northern Hemisphere (NH) and Southern Hemisphere (SH) high latitude regions for BC burden and at SH high latitude regions for deposition fluxes. The ACCMIP simulations match the observed BC surface mass concentrations well in Europe and North America except at Ispra. However, the models fail to predict the Arctic BC seasonality due to severe underestimations during winter and spring. The simulated vertically resolved BC snow concentrations are, on average, within a factor of 2-3 of the BC snowpack measurements except for Greenland and the Arctic Ocean. For the ice core evaluation, models tend to adequately capture both the observed temporal trends and the magnitudes at Greenland sites. However, models fail to predict the decreasing trend of BC depositions/ice core concentrations from the 1950s to the 1970s in most Tibetan Plateau ice cores. The distinct temporal trend at the Tibetan Plateau ice cores

  19. Evaluation of preindustrial to present-day black carbon and its albedo forcing from Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)

    NASA Astrophysics Data System (ADS)

    Lee, Y. H.; Lamarque, J.-F.; Flanner, M. G.; Jiao, C.; Shindell, D. T.; Berntsen, T.; Bisiaux, M. M.; Cao, J.; Collins, W. J.; Curran, M.; Edwards, R.; Faluvegi, G.; Ghan, S.; Horowitz, L. W.; McConnell, J. R.; Ming, J.; Myhre, G.; Nagashima, T.; Naik, V.; Rumbold, S. T.; Skeie, R. B.; Sudo, K.; Takemura, T.; Thevenon, F.; Xu, B.; Yoon, J.-H.

    2013-03-01

    As part of the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), we evaluate the historical black carbon (BC) aerosols simulated by 8 ACCMIP models against observations including 12 ice core records, long-term surface mass concentrations, and recent Arctic BC snowpack measurements. We also estimate BC albedo forcing by performing additional simulations using offline models with prescribed meteorology from 1996-2000. We evaluate the vertical profile of BC snow concentrations from these offline simulations using the recent BC snowpack measurements. Despite using the same BC emissions, the global BC burden differs by approximately a factor of 3 among models due to differences in aerosol removal parameterizations and simulated meteorology: 34 Gg to 103 Gg in 1850 and 82 Gg to 315 Gg in 2000. However, the global BC burden from preindustrial to present-day increases by 2.5-3 times with little variation among models, roughly matching the 2.5-fold increase in total BC emissions during the same period. We find a large divergence among models at both Northern Hemisphere (NH) and Southern Hemisphere (SH) high latitude regions for BC burden and at SH high latitude regions for deposition fluxes. The ACCMIP simulations match the observed BC surface mass concentrations well in Europe and North America except at Ispra. However, the models fail to predict the Arctic BC seasonality due to severe underestimations during winter and spring. The simulated vertically resolved BC snow concentrations are, on average, within a factor of 2-3 of the BC snowpack measurements except for Greenland and the Arctic Ocean. For the ice core evaluation, models tend to adequately capture both the observed temporal trends and the magnitudes at Greenland sites. However, models fail to predict the decreasing trend of BC depositions/ice core concentrations from the 1950s to the 1970s in most Tibetan Plateau ice cores. The distinct temporal trend at the Tibetan Plateau ice cores

  20. Late Miocene to present-day exhumation and uplift of the Internal Zone of the Rif chain: Insights from low temperature thermochronometry and basin analysis

    NASA Astrophysics Data System (ADS)

    Romagny, A.; Ph. Münch; Cornée, J.-J.; Corsini, M.; Azdimousa, A.; Melinte-Dobrinescu, M. C.; Drinia, H.; Bonno, M.; Arnaud, N.; Monié, P.; Quillévéré, F.; Ben Moussa, A.

    2014-07-01

    Located on the margin of the west Alboran basin, the Gibraltar Arc (Betic-Rif mountain belt) displays post-Pliocene vertical movements evidenced by uplifted marine sedimentary basins and marine terraces. Quantification of vertical movements is an important clue to understand the origin of present-day relief generation in the Betic-Rif mountain chain together with the causes of the Messinian Salinity Crisis. In this paper, we present the results of a pluridisciplinary study combining an analysis of low temperature thermochronology and Pliocene basins evolution to constrain the exhumation history and surface uplift of internals units of the Rif belt (Northern Morocco). The mean (U-Th)/He apatite ages obtained from 11 samples are comprised between 14.1 and 17.8 Ma and display a wide dispersion, which could be explained by a great variability of apatite chemistries in the analyzed samples. No correlations between altitude and age have been found along altitudinal profile suggesting a rapid exhumation during this period. Thermal modeling using our (U-Th)/He apatite ages and geochronological data previously obtained in the same area (40Ar/39Ar and K/Ar data on biotite, zircon and apatite fission track) allow us to propose a cooling history. The rocks suffered a rapid cooling at 60-100 °C/Ma between 22.5 and 19 Ma, then cooled to temperatures around 40 °C between 19 and 18 Ma. They were re-heated at around 110 °C between 18 and 15 Ma then rapidly cooled and exhumed to reach the surface temperature at around 13 Ma. The re-heating could be related to a renewal in thrusting and burying of the inner zones. Between 15 and 13 Ma the cooling resumed at a rate of 50 °C/Ma indicating an exhumation rate of 0.8 mm/y considering an average 40 °C/km geothermal gradient. This exhumation may be linked to the extension in the Alboran Sea. Otherwise biostratigraphic and sedimentological analysis of Pliocene basins of the internal Rif provided informations on the more recent events

  1. Population data of 24 STRs in Mexican-Mestizo population from Monterrey, Nuevo Leon (Northeast, Mexico) based on Powerplex(®) Fusion and GlobalFiler(®) kits.

    PubMed

    Ramos-González, Benito; Aguilar-Velázquez, José Alonso; Chávez-Briones, María de Lourdes; Delgado-Chavarría, Juan Ramón; Alfaro-Lopez, Elizabeth; Rangel-Villalobos, Héctor

    2016-03-01

    The STR loci included into new commercial human identification kits compels geneticists estimating forensic parameters for interpretation purposes in forensic casework. Therefore, we studied for the first time in Mexico the GlobalFiler(®) and Powerplex(®) Fusion systems in 326 and 682 unrelated individuals, respectively. These individuals are resident of the Monterrey City of the Nuevo Leon state (Northeast, Mexico). Population data from 23 autosomal STRs and the Y-STR locus DYS391 are reported and compared against available STR data from American ethnic groups and the unique Mexican population studied with Powerplex(®) Fusion.

  2. Population data of 24 STRs in Mexican-Mestizo population from Monterrey, Nuevo Leon (Northeast, Mexico) based on Powerplex(®) Fusion and GlobalFiler(®) kits.

    PubMed

    Ramos-González, Benito; Aguilar-Velázquez, José Alonso; Chávez-Briones, María de Lourdes; Delgado-Chavarría, Juan Ramón; Alfaro-Lopez, Elizabeth; Rangel-Villalobos, Héctor

    2016-03-01

    The STR loci included into new commercial human identification kits compels geneticists estimating forensic parameters for interpretation purposes in forensic casework. Therefore, we studied for the first time in Mexico the GlobalFiler(®) and Powerplex(®) Fusion systems in 326 and 682 unrelated individuals, respectively. These individuals are resident of the Monterrey City of the Nuevo Leon state (Northeast, Mexico). Population data from 23 autosomal STRs and the Y-STR locus DYS391 are reported and compared against available STR data from American ethnic groups and the unique Mexican population studied with Powerplex(®) Fusion. PMID:26747399

  3. The Impact of LEP G-2548A and LEPR Gln223Arg Polymorphisms on Adiposity, Leptin, and Leptin-Receptor Serum Levels in a Mexican Mestizo Population.

    PubMed

    Chavarria-Avila, Efraín; Vázquez-Del Mercado, Mónica; Gomez-Bañuelos, Eduardo; Ruiz-Quezada, Sandra-Luz; Castro-Albarran, Jorge; Sánchez-López, Lizeth; Martín-Marquez, Beatriz Teresita; Navarro-Hernández, Rosa-Elena

    2015-01-01

    The polymorphisms in leptin (LEP G-2548A) and leptin-receptor (LEPR Gln223Arg) seem to influence obesity and lipid metabolism among others. The aim of this study was to investigate the effect of these polymorphisms on adiposity, leptin (sLeptin), and leptin-receptor (sLeptin-receptor) serum concentrations as well as inflammation markers. We included 382 adults originally from Western Mexico. They were genotyped by PCR-RFLP. Obese individuals showed higher sLeptin (58.2 ± 31.35 ng/mL) but lower sLeptin-receptor (12.6 ± 3.74 ng/mL) levels than normal weight ones (17.6 ± 14.62 ng/mL, 17.4 ± 4.62 ng/mL, resp.), P < 0.001. Obese subjects carriers of Arg/Arg genotype had more (P = 0.016) sLeptin-receptor (14.7 ± 4.96 ng/mL) and less (P = 0.004) sLeptin (44.0 ± 28.12 ng/mL) levels than Gln/Gln genotype (11.0 ± 2.92 ng/mL, 80.3 ± 33.24 ng/mL, resp.). Body fat mass was lower (P from 0.003 to 0.045) for A/A (36.5% ± 6.80) or Arg/Arg (36.8% ± 6.82) genotypes with respect to G/G (41.3% ± 5.52) and G/A (41.6% ± 5.61) or Gln/Gln (43.7% ± 4.74) and Gln/Arg (41.0% ± 5.52) genotypes carriers. Our results suggest that LEP -2548A and LEPR 223Arg could be genetic markers of less body fat mass accumulation in obese subjects from Western Mexico.

  4. The Impact of LEP G-2548A and LEPR Gln223Arg Polymorphisms on Adiposity, Leptin, and Leptin-Receptor Serum Levels in a Mexican Mestizo Population

    PubMed Central

    Chavarria-Avila, Efraín; Gomez-Bañuelos, Eduardo; Ruiz-Quezada, Sandra-Luz; Castro-Albarran, Jorge; Sánchez-López, Lizeth; Martín-Marquez, Beatriz Teresita; Navarro-Hernández, Rosa-Elena

    2015-01-01

    The polymorphisms in leptin (LEP G-2548A) and leptin-receptor (LEPR Gln223Arg) seem to influence obesity and lipid metabolism among others. The aim of this study was to investigate the effect of these polymorphisms on adiposity, leptin (sLeptin), and leptin-receptor (sLeptin-receptor) serum concentrations as well as inflammation markers. We included 382 adults originally from Western Mexico. They were genotyped by PCR-RFLP. Obese individuals showed higher sLeptin (58.2 ± 31.35 ng/mL) but lower sLeptin-receptor (12.6 ± 3.74 ng/mL) levels than normal weight ones (17.6 ± 14.62 ng/mL, 17.4 ± 4.62 ng/mL, resp.), P < 0.001. Obese subjects carriers of Arg/Arg genotype had more (P = 0.016) sLeptin-receptor (14.7 ± 4.96 ng/mL) and less (P = 0.004) sLeptin (44.0 ± 28.12 ng/mL) levels than Gln/Gln genotype (11.0 ± 2.92 ng/mL, 80.3 ± 33.24 ng/mL, resp.). Body fat mass was lower (P from 0.003 to 0.045) for A/A (36.5% ± 6.80) or Arg/Arg (36.8% ± 6.82) genotypes with respect to G/G (41.3% ± 5.52) and G/A (41.6% ± 5.61) or Gln/Gln (43.7% ± 4.74) and Gln/Arg (41.0% ± 5.52) genotypes carriers. Our results suggest that LEP -2548A and LEPR 223Arg could be genetic markers of less body fat mass accumulation in obese subjects from Western Mexico. PMID:26064921

  5. A Non-Rigid Block Extrusion Induced by Arc-Continent Collision Corner: Present-day Crustal Deformation and Neotectonics in Northern Hualien, Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, C.; Lee, J.; Chen, Y.; Chen, R.

    2009-12-01

    Eastern Taiwan has long been well-known as sitting at the collision suture between the Eurasian and Philippine Sea plates which is characterized by numerous earthquakes and several active faults. The Hualien City is located at the transition point at the northern end of the Longitudinal Valley, whereas the Philippine Sea plate was westward thrust upon the Eurasian plate in the past, while is diving right now under the Eurasian plate from the latitude of Hualien northwards. At least one major active fault has been documented in this relatively complex area of transition zone, in addition to the Coastal Range fault on the northwestern side of the Coastal Range. The Milun fault has been mapped running along the western margin of the Milun Tableland, showing coseismic slips of 1.2 and 2 m for its vertical and sinistral slip respectively during the 1951 M=7.3 Hualien earthquake. Based on (1) repeated GPS campaign measurements for five times during April 2007 to July 2009, (2) D-InSAR analysis and (3) repeated leveling and total station measurements at a near-fault network, we obtained the horizontal and vertical crustal deformation in this area. The results suggest an eastward extrusion in the northern Hualien area. We tend to interpret it as being initiated by the northwest indentation of the Coastal Range under the sea to push the northeastern Hualien not only move upward but also eastward because of free space in the up and east directions. On the other hand, the strain analyses of GPS data indicate that the northern Hualien is far from a rigid block, as revealed by inhomogeneous GPS velocity field. Our measurements also indicate that the Milun fault probably is now locked. No significant horizontal or vertical offset was observed across the fault, although local network showed a contraction strain in the surface fault zone. We tend to interpret the Milun fault as a high-angle sinistral fault that was formed within the extrusion block, that allow the Milun Tableland

  6. Benthic foraminifera from the deep-water Niger delta (Gulf of Guinea): Assessing present-day and past activity of hydrate pockmarks

    NASA Astrophysics Data System (ADS)

    Fontanier, C.; Koho, K. A.; Goñi-Urriza, M. S.; Deflandre, B.; Galaup, S.; Ivanovsky, A.; Gayet, N.; Dennielou, B.; Grémare, A.; Bichon, S.; Gassie, C.; Anschutz, P.; Duran, R.; Reichart, G. J.

    2014-12-01

    13C values. Dead faunas carry a complex time-averaged message, integrating taphonomic gains and losses related to the temporal variability of gas emission. They reveal major faunal differences that may be useful to detect gas hydrate seepages in different pockmark stages.

  7. Geochemical evidence of present-day serpentinization

    USGS Publications Warehouse

    Barnes, I.; LaMarche, Valmore C.; Himmelberg, G.

    1967-01-01

    Ultrabasic (pH > 11) water issues from some fresh ultramafic bodies. The properties of the ultrabasic solutions are believed to be due to current reactions yielding serpentine from primary olivines and pyroxenes. The low concentrations of divalent iron, divalent magnesium, and dissolved silica from the serpentinization require an increase in rock volume.

  8. Cosmology: from Pomeranchuk to the Present Day

    NASA Astrophysics Data System (ADS)

    Dolgov, A. D.

    A short and, due to lack of time (half a century of the science progress in half an hour), rather superficial review on the development of cosmology for scientists working on particle and nuclear physics is presented. The introductory historical part is mostly dedicated to the fundamental works done in Russia (USSR), but not always well known outside the country. Next, the key papers on theory and on astronomical observations, which determined the progress in cosmology during the last half-century or posed crucial problem, are discussed. Among them there are inflation, baryogenesis, dark matter, dark energy, the vacuum energy problem, modification of gravity at large scales, and angular fluctuations of the cosmic microwave background radiation. The presentation is probably biased towards cosmology as it is seen from Russia (or from ITEP) and reflects personal prejudice of the author.

  9. [Present day Marxist sociology and psychoanalysis].

    PubMed

    Biran, S

    1979-01-01

    The main common theme in psychoanalysis and Marxist sociology is the understanding that it is not consciousness that determines being, but being (spiritual, social) that determines consciousness. The different variations of Marxist movements today are in fact distant from Marx's theory of sociology. They have become representatives of utopian socialism, using anarchistic methods to achieve that aim. This development can only be understood as a social neurosis, with the narcistic frustation of the intellectual class as its cause, and grandiose claims, intolerance, dogmatic thinking and destructive behaviour as its symptoms. The only justified criticism of psychoanalysis from the pseudo-Marxist side is based on the imperfection and error in the analytical doctrine of superego. This should be replaced by the idea of conscious, subjective, emotional morality which clearly explains the aggression contained in social structures. PMID:498762

  10. Global three-dimensional model calculations of the budgets and present-day atmospheric lifetimes of CF2ClCFCl2 (CFC-113) and CHClF2 (CFC-22)

    NASA Technical Reports Server (NTRS)

    Golombek, Amram; Prinn, Ronald G.

    1989-01-01

    The annual percentage increases in concentrations of the chlorofluorocarbons CFC-113 (an industrial solvent) and CFC-22 (a refrigerant) are the highest among major chlorofluorocarbons in the atmosphere today. The present-day atmospheric lifetimes for these species are computed using a global three-dimensional dynamical-chemical model. The present-day lifetimes of both are long (15.5 years for CFC-22 and 136 or 195 years for CFC-113, depending on assumed O2 absorption cross sections), underscoring the need to decrease their emissions in order to minimize their future role in ozone destruction and greenhouse warming.

  11. Using present-day patterns of interseismic coupling to model the C.E. 1707 Hōei earthquake and simulate tsunami inundation of Lake Ryuuoo in the Bungo Channel, southwestern Japan

    NASA Astrophysics Data System (ADS)

    Baranes, H. E.; Woodruff, J. D.; Loveless, J. P.; Cheng, W.; Weiss, R.; Kanamaru, K.

    2015-12-01

    The C.E. 1707 Hōei event is often considered the worst-case scenario for a Nankai Trough earthquake and tsunami impacting southwestern Japan, and recent estimates of the earthquake's magnitude have exceeded MW 9. However, when paired with tsunami simulations, previously published earthquake models for the event fail to match sedimentological and historical records of 1707 tsunami height in Shikoku and Kyushu. Specifically, models do not produce a sufficiently large tsunami in the northern Bungo Channel and Seto Inland Sea without also over-predicting tsunami heights along the open Pacific coastlines of Shikoku and Kyushu. Here, we apply a newly developed rupture model that uses present-day patterns of geodetically imaged interseismic coupling to inform patterns in coseismic slip. Along the southwestern extent of the plate interface (the Hyuga-nada area), there is a region of weak coupling up-dip along the trench axis and a region of strong coupling down-dip beneath Shikoku and Kyushu. Following this pattern, the new earthquake model produces less coseismic uplift offshore and greater subsidence in an inland region that includes the Bungo Channel. This combination of regional subsidence and a tsunami wave more focused to the Bungo Channel results in inundation patterns more consistent with historical and sedimentological observations in the Hyuga-nada area. We also run the tsunami simulation on a high-resolution grid around Lake Ryuuoo, a back-barrier lake in the northern Bungo Channel that contains a marine overwash deposit from the 1707 tsunami. We apply a simple sediment transport model to demonstrate that the coupling-based rupture scenario produces flow over Lake Ryuuoo's barrier capable of transporting the maximum grain size observed in the lake's 1707 deposit. These findings suggest that spatial trends in our present-day coupling model are more consistent with inundation patterns observed for large tsunamis generated by coseismic rupture along the Nankai

  12. Seafloor morphology of the Eurasia-Nubia (Africa) plate boundary between the Tore-Madeira Rise and the Straits of Gibraltar: a case of coexistent Mesozoic through Present day features of tectonic, oceanographic and sedimentary origin

    NASA Astrophysics Data System (ADS)

    Terrinha, Pedro; Duarte, João.; Valadares, Vasco; Batista, Luis; Zitellini, Nevio; Grácia, Eulalia; Lourenço, Nuno; Rosas, Filipe; Roque, Cristina

    2010-05-01

    The joint use of more than 10.000 km multichannel seismic reflection profiles and 180.000km2 of multibeam swath bathymetry and backscatter allowed for a new vision of the seafloor tectonic and geomorphic processes of the area that encompasses the present day plate boundary between Africa and Eurasia, between the Gibraltar Straits and the Tore-Madeira Rise, in the southern sector of the North Atlantic Ocean. The interpretation of this data allowed for the detailed description of the seafloor morphology (i.e. a morphologic map) and the classification of the morphologic features in what respects the genetic process and age. It can be seen that in the same region coexist morphologic features that result from tectonic processes associated with the Triassic-Cretaceous break-up of Pangea, the Paleogene-Miocene compressive phase, the Miocene through Present subduction under the Gibraltar Arc (Gutscher et al., 2002), the Pliocene-Quaternary wrench tectonics and possible coeval plate boundary (Zitellini et al., 2009), the Present day mud volcanism and propagation of the compressive deformation along the West Continental Margin of Portugal (Terrinha et al., 2009). Interpretation of the seismic profiles together with the bathymetry allows the understanding of endogenous and exogenous processes that creates reliefs associated with active structures (related to the Miocene through Present compressive stress field). Other reliefs generated in Mesozoic times by analogous processes can be as well preserved as these active ones. In what concerns exogenous processes, the analysis of the two datasets (reflection seismics and bathymetry) allowed for the description of morphologic features associated with oceanic currents that interact with the seafloor forming these important features. As is the case of the well known active contourites but also less known features, like giant scours at 4 km water depth that have recently been described, suggesting the interaction of deep currents and

  13. The structure of basement highs at deep-water, hyper-extended rifted margins: the example of the Briançonnais domain in the Alps and present-day examples from the Atlantic and Indian oceans

    NASA Astrophysics Data System (ADS)

    Haupert, Isabelle; Manatschal, Gianreto; Decarlis, Alessandro; Mohn, Geoffroy; Unternehr, Patrick

    2014-05-01

    in the Alps that can be compared to the structures imaged across basement highs at hyperextended domains along the Atlantic and Indian margins. This approach will enable to better define and understand the pre-Alpine 3D architecture of the Briançonnais in the Alps as well as to get insights on the structural and stratigraphic architecture of basement highs at present-day rifted margins.

  14. Sedimentological imprints of environmental variability at the Balkan Peninsula on the sediment sequence of Lake Ohrid (Macedonia, Albania) between the Mid Pleistocene Transition and present days: The ICDP SCOPSCO project

    NASA Astrophysics Data System (ADS)

    Francke, Alexander; Wagner, Bernd; Leicher, Niklas; Raphael, Gromig; Leng, Melanie; Lacey, Jack; Vogel, Hendrik; Baumgarten, Henrike; Thomas, Wonik; Zanchetta, Giovanni; Roberto, Sulpizio; Krastel, Sebastian; Lindhorst, Katja

    2015-04-01

    The UNESCO World Heritage site of Lake Ohrid in the Balkans is thought to be the oldest, continuously existing lake in Europe. In order to unravel the geological and evolutionary history of the lake, a deep drilling campaign was conducted in spring 2013 under the umbrella of the ICDP SCOPSCO project. At the coring site "DEEP" in central parts of the lake, more than 1,500 m of sediments were recovered down to a penetration depth of 569 m blf. This sediment sequence is assumed to be more than 1.2 Ma old and likely covers the entire lacustrine deposits of the Lake Ohrid Basin. Currently, an age model for the upper 260m of the DEEP- site sequence is available. This age model is based on chronological tie points (tephrochronology), and wiggle matching of down hole logging data and (bio-)geochemistry data (XRF, TIC, TOC) from the core sequence to the global benthic stack LR04 and local insolation patterns. The data suggests that the upper 260 m of the DEEP-site sequence corresponds to the time period between the Mid Pleistocene Transition (MPT) and present days. During this period, the sedimentological properties of the sediments show a strong dependency on environmental variability in the area. Interglacial deposits appear massive or marbled, contain up to 80 % of CaCO3 (high TIC), high amounts of organic matter (high TOC) and biogenic silica (high BSi), and low contents of clastic material. Glacial deposits are predominantly marbled and calcite is generally absent. Similarly, the amounts of organic matter and biogenic silica are low, and glacial sediments predominately consist of clastic matter. Distinct layers of siderite and uniformly distributed Fe- or Mn- oxides occur in the glacial deposits, vivianite concretions occur in both the glacial and interglacial periods. High CaCO3 contents in deposits formed during warm (interglacial) periods are also known from studies on short pilot cores from Lake Ohrid and are triggered by increased productivity in the lake, such as

  15. Assessing the volcanic hazard for Rome: 40Ar/39Ar and In-SAR constraints on the most recent eruptive activity and present-day uplift at Colli Albani Volcanic District

    NASA Astrophysics Data System (ADS)

    Marra, F.; Gaeta, M.; Giaccio, B.; Jicha, B. R.; Palladino, D. M.; Polcari, M.; Sottili, G.; Taddeucci, J.; Florindo, F.; Stramondo, S.

    2016-07-01

    We present new 40Ar/39Ar data which allow us to refine the recurrence time for the most recent eruptive activity occurred at Colli Albani Volcanic District (CAVD) and constrain its geographic area. Time elapsed since the last eruption (36 kyr) overruns the recurrence time (31 kyr) in the last 100 kyr. New interferometric synthetic aperture radar data, covering the years 1993-2010, reveal ongoing inflation with maximum uplift rates (>2 mm/yr) in the area hosting the most recent (<200 ka) vents, suggesting that the observed uplift might be caused by magma injection within the youngest plumbing system. Finally, we frame the present deformation within the structural pattern of the area of Rome, characterized by 50 m of regional uplift since 200 ka and by geologic evidence for a recent (<2000 years) switch of the local stress-field, highlighting that the precursors of a new phase of volcanic activity are likely occurring at the CAVD.

  16. The (G>A) rs11573191 polymorphism of PLA2G5 gene is associated with premature coronary artery disease in the Mexican Mestizo population: the genetics of atherosclerotic disease Mexican study.

    PubMed

    Vargas-Alarcón, Gilberto; Posadas-Romero, Carlos; Villarreal-Molina, Teresa; Alvarez-León, Edith; Angeles-Martinez, Javier; Soto, María Elena; Monroy-Muñoz, Irma; Juárez, Juan Gabriel; Sánchez-Ramírez, Carlos Jerges; Ramirez-Bello, Julian; Ramírez-Fuentes, Silvestre; Fragoso, José Manuel; Rodríguez-Pérez, José Manuel

    2014-01-01

    Coronary artery disease (CAD) is a multifactorial disorder that results from an excessive inflammatory response. Secretory phospholipase A2-V (sPLA2-V) encoded by PLA2G5 gene promotes diverse proinflammatory processes. The aim of the present study was to analyze if PLA2G5 gene polymorphisms are associated with premature CAD. Three PLA2G5 polymorphisms (rs11573187, rs2148911, and rs11573191) were analyzed in 707 patients with premature CAD and 749 healthy controls. Haplotypes were constructed after linkage disequilibrium analysis. Under dominant, recessive, and additive models, the rs11573191 polymorphism was associated with increased risk of premature CAD (OR = 1.51, P(dom) = 3.5 × 10(-3); OR = 2.95, P(rec) = 0.023; OR = 1.51, P(add) = 1.2 × 10(-3)). According to the informatics software, this polymorphism had a functional effect modifying the affinity of the sequence by the MZF1 transcription factor. PLA2G5 polymorphisms were in linkage disequilibrium and the CGA haplotype was associated with increased risk of premature CAD (OR = 1.49, P = 0.0023) and with hypertension in these patients (OR = 1.75, P = 0.0072). Our results demonstrate the association of the PLA2G5 rs11573191 polymorphism with premature CAD. In our study, it was possible to distinguish one haplotype associated with increased risk of premature CAD and hypertension.

  17. [Situation of sultopride among present-day neuroleptics].

    PubMed

    Maurel, H; Pujol, B

    1975-01-01

    The authors report preliminary clinical investigations about sultopride, a new substituted benzamid, related to sulpiride. The drug was administered to thirty-nine hospitalized psychotic patients. A very powerful and constant efficacy of sultopride was observed in 11 manic and hypomanic typical syndroms: excitation was controlled between the first and third day, with oral doses of 1,200-1,800 mg. But thymical inversion was observed in 8 cases (3 light anxious states and 5 typical melancholic syndroms). Besides, interesting improvements were obtained in atypical excitation disorders, chronic hallucinatory delusions, acute oniric and confusional states, schizophrenia and chronic alcoholism. Side-effects were frequent: extrapyramidal syndroms, often requiring antiparkinsonian correctors, somnolence, asthenia, and above all (in 30 percent of cases) psychical side-effects, consisting in depressive and anxious modifications of mood, even apart from manic-melancholic psychosis. This psychotropic depressive effect appears as very interesting theoretically, and justifies further enquiry.

  18. Earthquakes and present-day tectonism in Iceland

    NASA Astrophysics Data System (ADS)

    Einarsson, Páll

    1991-04-01

    The mid-Atlantic plate boundary in Iceland is expressed by a series of seismic and volcanic zones. The structure of the plate boundary is strongly influenced by the Iceland hot spot. The relative motion of the Mid-Atlantic Ridge with respect to the hot spot leads to ridge jumps, propagating rifts and other complexities. Most large earthquakes in Iceland occur within two transform zones that connect the presently active Northern and Eastern Volcanic Zones to the ridges offshore. In the south the South Iceland Seismic Zone is marked by a 10-15 km wide, E-trending epicentral belt. The large earthquakes occur by faulting on N-S striking right-lateral faults. The left-lateral transform motion along the zone thus appears to be taken up by slip on numerous parallel faults by counterclockwise rotation of the blocks between them (bookshelf tectonics). It is argued that the South Iceland Seismic Zone is a transient feature, migrating sideways in response to propagation of the Eastern Volcanic Zone. In Northern Iceland the transform motion is taken up along the Tjörnes Fracture Zone. At least three parallel, NW-trending seismic belts have been identified within the zone. The seismicity of the volcanic zones is characterized by spatial clustering of epicenters. Most clusters coincide with central volcanoes. Rifting structures such as fissure swarms and normal faults are mostly aseismic except during episodes of rifting and magmatism such as the present events in Krafla. Earthquake recording has been used very successfully at Krrafla to monitor the level of inflation and deflation of the volcano, and to trace the path and speed of lateral magmatic intrusions into the associated fissure swarm. Seismic activity at the Bárdarbunga volcano in Central Iceland correlates in time with the Krafla events, and it seems as if inflation of Krafla is followed by deflation of Bárdarbunga. It is postulated that the pressure drop in the partially molten mantle beneath Krafla is transmitted to neighboring volcanoes, leading to magma withdrawal from their shallow reservoirs. Bursts of seismicity of the Katla volcano in South Iceland in 1967 and 1977 may similarly be the result of magma withdrawal in response to the 1964-1967 Surtsey and 1973 Heimaey eruptions. Annual periodicity seen in the Katla seismicity is explained as the result of the triggering effect of pore pressure in the crust beneath the glacier covering Katla. Several volcanoes exhibit persistent, low-magnitude seismicity. In the Hengill volcano in Southwest Iceland, many events involve a non-double-couple mechanism. The seismicity is interpreted as the result of extensional failure and heat extraction from a cooling magma chamber. Two classes of intraplate earthquakes have been identified in Iceland. One includes events in the lithospheric blockbetween the transform zones. These events are related to crustal extension above the hot spot. The other class includes events on the insular shelf off the east and southeast coasts which are possibly caused by a differential cooling rate in the crust across the shelf edge.

  19. Teaching with Social Media: Disrupting Present Day Public Education

    ERIC Educational Resources Information Center

    Meabon Bartow, Susan

    2014-01-01

    Because social technologies present illuminating educational, ethical, economic, and structural challenges to existing constructions of public education, they catalyze a fundamental examination of what public education should look like and be like in a democracy. Given their performances in other arenas, mobile and electronic technologies have the…

  20. The ethical debate on present day paternity testing practices.

    PubMed

    Mertens, G

    2006-01-01

    The last years, the number of paternity tests on buccal swabs sold over the internet as "test kits", has steeply increased. The commercial providers of these services facilitate controversial practices, including clandestine sampling at home, anonymous sending off for analysis, motherless testing and using "stolen" personal objects containing biological material (combs, cigarette butts). This has led to concern on the consequences on the family unit--especially the child--which may suffer emotionally, physically and financially. In reaction, legal initiatives are appearing throughout Europe. The UK Human Genetics Commission has advised that the non-consensual obtaining and analysis of personal genetic information should be a new criminal offence. The German Federal Court of Justice has ruled that paternity tests performed without the mother's knowledge are inadmissible as evidence in lawsuits. French law strictly forbids the application of DNA testing without the involvement of the court system. In Belgium, a proposal for law has been laid down where the offering to PMID:16792338

  1. Human Capital and Its Development in Present-Day Russia

    ERIC Educational Resources Information Center

    Nureev, R. M.

    2010-01-01

    In the broad sense of the word human capital is a specific form of capital that is embodied in people themselves. It consists of the individual's reserve of health, knowledge, skills, abilities, and motivations that enable him to increase his labor productivity and give him an income in the form of wages, salaries, and other income. The structure…

  2. Present day serpentinization in New Caledonia, Oman and Yugoslavia

    USGS Publications Warehouse

    Barnes, I.; O'Neil, J.R.; Trescases, J.J.

    1978-01-01

    Geochemical evidence for modern low-temperature serpentinization has been found in three new localities. Apparently the low-temperature reactions are a common mode of formation of the lizardite-chrysotile and brucite assemblage. Possibly the 18O content of serpentine formed at low temperatures is in part inherited from the pyroxene and olivine. ?? 1978.

  3. A comparative study of prebiotic and present day translational models

    NASA Technical Reports Server (NTRS)

    Rein, R.; Raghunathan, G.; Mcdonald, J.; Shibata, M.; Srinivasan, S.

    1986-01-01

    It is generally recognized that the understanding of the molecular basis of primitive translation is a fundamental step in developing a theory of the origin of life. However, even in modern molecular biology, the mechanism for the decoding of messenger RNA triplet codons into an amino acid sequence of a protein on the ribosome is understood incompletely. Most of the proposed models for prebiotic translation lack, not only experimental support, but also a careful theoretical scrutiny of their compatibility with well understood stereochemical and energetic principles of nucleic acid structure, molecular recognition principles, and the chemistry of peptide bond formation. Present studies are concerned with comparative structural modelling and mechanistic simulation of the decoding apparatus ranging from those proposed for prebiotic conditions to the ones involved in modern biology. Any primitive decoding machinery based on nucleic acids and proteins, and most likely the modern day system, has to satisfy certain geometrical constraints. The charged amino acyl and the peptidyl termini of successive adaptors have to be adjacent in space in order to satisfy the stereochemical requirements for amide bond formation. Simultaneously, the same adaptors have to recognize successive codons on the messenger. This translational complex has to be realized by components that obey nucleic acid conformational principles, stabilities, and specificities. This generalized condition greatly restricts the number of acceptable adaptor structures.

  4. Syphilis: An Old Disease With Present-Day Implications.

    PubMed

    McNeil, Candice J; Bachmann, Laura H

    2016-01-01

    Syphilis continues to be a burden on the public health system. While men who have sex with men and HIV-infected individuals are the most affected populations, syphilis rates have also increased in reproductive-aged women, resulting in concurrent increases in congenital syphilis. Prompt diagnosis and treatment are requisite components of syphilis control. PMID:27621352

  5. [Present-day metal-cutting tools and working conditions].

    PubMed

    Kondratiuk, V P

    1990-01-01

    Polyfunctional machine-tools of a processing centre type are characterized by a set of hygienic advantages as compared to universal machine-tools. But low degree of mechanization and automation of some auxiliary processes, and constructional defects which decrease the ergonomic characteristics of the tools, involve labour intensity in multi-machine processing. The article specifies techniques of allowable noise level assessment, and proposes hygienic recommendations, some of which have been introduced into practice.

  6. Syphilis: An Old Disease With Present-Day Implications.

    PubMed

    McNeil, Candice J; Bachmann, Laura H

    2016-01-01

    Syphilis continues to be a burden on the public health system. While men who have sex with men and HIV-infected individuals are the most affected populations, syphilis rates have also increased in reproductive-aged women, resulting in concurrent increases in congenital syphilis. Prompt diagnosis and treatment are requisite components of syphilis control.

  7. Catalogues of variable stars from Parenago to the present day

    NASA Astrophysics Data System (ADS)

    Samus, N. N.

    2006-04-01

    After World War II, the International Astronomical Union made Soviet astronomers responsible for variable-star catalogues. This work has been continued ever since the first edition of the General Catalogue of Variable Stars compiled by the team headed by P.P. Parenago and B.V. Kukarkin and published in 1948. Currently, the catalogue work is a joint project of the Institute of Astronomy (Russian Academy of Sciences) and the Sternberg Astronomical Institute (Moscow University). This paper is a brief review of recent trends in the field of variable-star catalogues. Problems as well as new prospects related to modern large-scale automatic photometric sky surveys are discussed.

  8. [Fire worship on Soratte: form prehistory to present days].

    PubMed

    Falchetti, Mario; Ottini, Laura

    2013-01-01

    Fire has always been involved in human thoughts, believes and actions. For many psychological reasons fire has been considered as living power: red as the human blood, warm as the human body, clearly shines in the night. Fire worship is very common, especially in regions where terrestrial fire is believed to be the image of the heavenly fire. Fire worship has represented the base for symbolic systems involved in the cultural-anthropological evolution of populations settled close to mount Soratte. Fire cults in this region have originated in independent and long-time separated contexts, according to available knowledge. Hirpi Sorani, ancient inhabitants of mount Soratte territory, celebrated Sorano Apollo by a famous fire walking ceremony, with a likely cathartic and apotropaic meaning, as reported by ancient Roman writers. The victory of Christianity over paganism caused the decline of these religious practices. The beginning of the XIX century witnessed the establishment ofa new kind of devotion to the Virgin Mary at the mount Soratte. Today, this religious piety-linked identity has weakened due to changes in lifestyles,from an agricultural to one based on outside home employment, and has been largely shifted on cultural and anthropological bases. In conclusion, fire worship at mount Soratte has evolved because of external influences and local inhabitants have reacted by asserting their own identity. PMID:25807785

  9. Present-day uplift of the western Alps

    PubMed Central

    Nocquet, J.-M.; Sue, C.; Walpersdorf, A.; Tran, T.; Lenôtre, N.; Vernant, P.; Cushing, M.; Jouanne, F.; Masson, F.; Baize, S.; Chéry, J.; van der Beek, P. A.

    2016-01-01

    Collisional mountain belts grow as a consequence of continental plate convergence and eventually disappear under the combined effects of gravitational collapse and erosion. Using a decade of GPS data, we show that the western Alps are currently characterized by zero horizontal velocity boundary conditions, offering the opportunity to investigate orogen evolution at the time of cessation of plate convergence. We find no significant horizontal motion within the belt, but GPS and levelling measurements independently show a regional pattern of uplift reaching ~2.5 mm/yr in the northwestern Alps. Unless a low viscosity crustal root under the northwestern Alps locally enhances the vertical response to surface unloading, the summed effects of isostatic responses to erosion and glaciation explain at most 60% of the observed uplift rates. Rock-uplift rates corrected from transient glacial isostatic adjustment contributions likely exceed erosion rates in the northwestern Alps. In the absence of active convergence, the observed surface uplift must result from deep-seated processes. PMID:27346228

  10. Present-day uplift of the western Alps.

    PubMed

    Nocquet, J-M; Sue, C; Walpersdorf, A; Tran, T; Lenôtre, N; Vernant, P; Cushing, M; Jouanne, F; Masson, F; Baize, S; Chéry, J; van der Beek, P A

    2016-06-27

    Collisional mountain belts grow as a consequence of continental plate convergence and eventually disappear under the combined effects of gravitational collapse and erosion. Using a decade of GPS data, we show that the western Alps are currently characterized by zero horizontal velocity boundary conditions, offering the opportunity to investigate orogen evolution at the time of cessation of plate convergence. We find no significant horizontal motion within the belt, but GPS and levelling measurements independently show a regional pattern of uplift reaching ~2.5 mm/yr in the northwestern Alps. Unless a low viscosity crustal root under the northwestern Alps locally enhances the vertical response to surface unloading, the summed effects of isostatic responses to erosion and glaciation explain at most 60% of the observed uplift rates. Rock-uplift rates corrected from transient glacial isostatic adjustment contributions likely exceed erosion rates in the northwestern Alps. In the absence of active convergence, the observed surface uplift must result from deep-seated processes.

  11. Present-day aeolian activity in Herschel Crater, Mars

    NASA Astrophysics Data System (ADS)

    Cardinale, Marco; Silvestro, Simone; Vaz, David A.; Michaels, Timothy; Bourke, Mary C.; Komatsu, Goro; Marinangeli, Lucia

    2016-02-01

    In this report, we show evidence for ripple and dune migration in Herschel Crater on Mars. We estimate an average dune migration of 0.8 m and a minimum ripple migration of 1.1 m in a time span of 3.7 Earth-years. These dunes and ripples are mainly shaped by prevailing winds coming from the north, however we also report the presence of secondary winds which elongate the barchans' horns. Such a complex wind scenario is likely caused by the influence of winds blowing off the western crater rim as suggested by the Mars Regional Atmospheric Modeling System (MRAMS), an atmospheric mesoscale model. A multi-directional wind regime at the local scale is also supported by the observed bimodal distribution of the ripple trends. For the first time, a survey integrating the assessment of dune and ripple migration is presented, showing how dune topography can influence the migration patterns of ripples and how underlying topography appears to control the rates of dune migration.

  12. Present-day uplift of the western Alps

    NASA Astrophysics Data System (ADS)

    Nocquet, J.-M.; Sue, C.; Walpersdorf, A.; Tran, T.; Lenôtre, N.; Vernant, P.; Cushing, M.; Jouanne, F.; Masson, F.; Baize, S.; Chéry, J.; van der Beek, P. A.

    2016-06-01

    Collisional mountain belts grow as a consequence of continental plate convergence and eventually disappear under the combined effects of gravitational collapse and erosion. Using a decade of GPS data, we show that the western Alps are currently characterized by zero horizontal velocity boundary conditions, offering the opportunity to investigate orogen evolution at the time of cessation of plate convergence. We find no significant horizontal motion within the belt, but GPS and levelling measurements independently show a regional pattern of uplift reaching ~2.5 mm/yr in the northwestern Alps. Unless a low viscosity crustal root under the northwestern Alps locally enhances the vertical response to surface unloading, the summed effects of isostatic responses to erosion and glaciation explain at most 60% of the observed uplift rates. Rock-uplift rates corrected from transient glacial isostatic adjustment contributions likely exceed erosion rates in the northwestern Alps. In the absence of active convergence, the observed surface uplift must result from deep-seated processes.

  13. Present-day anthelmintics and perspectives on future new targets.

    PubMed

    Taman, Amira; Azab, Manar

    2014-07-01

    In absence of vaccines for the majority of helminths, chemotherapy is still the mainstay for controlling human helminthiases. However, a limited number of drugs are available in the market to combat parasitic helminths in human. Besides, the development and spread of drug resistance have declined the use of most currently available anthelmintics. Clearly, availability of new anthelmintic agents will be essential in the next few years. More research into the mechanisms of drug actions and their targets are eminent for the discovery and development of novel anthelmintic agents. Recent drug discovery techniques mostly rely on mechanism-based screening of compounds on heterologously expressed targets in bacterial, mammalian or yeast cells. Although this is usually a successful approach, it is money- and time-consuming; meanwhile, pharmaceutical companies prefer the tested target that is chosen based on basic research. The nervous system is the site of action of several chemotherapeutics including pesticides and antinematode drugs; accordingly, the nervous system continues to be a promising target. Recent advances in exploring helminths' nervous system, neurotransmitters and receptors have paved the way for the development of potential agents targeting the nervous system and its components.

  14. Tracing galaxy evolution by their present-day luminosity function

    NASA Astrophysics Data System (ADS)

    Tempel, Elmo

    2011-04-01

    Galaxies, which are complex objects containing up to several tens of billions stars, as well as gas and dust, are remarkable objects. The Universe contains a very diverse "zoo" of galaxies: there are galaxies with a discy shape and spiral structure, elliptical galaxies, and even galaxies, which show no sign of structure. This variety of galaxies leads to the basic question: how the galaxies form and evolve and which processes shape the structure of galaxies? Due to the complexity of galaxy formation and evolution, this question is still an unresolved puzzle and it is one of the biggest challenges in modern cosmology. The present thesis is based on large galaxy surveys and concentrates on the large-scale structure: how galaxy evolution is related to the surrounding large-scale environment of superclusters and voids. To study the evolution of galaxies, we use the luminosity function, which is in this respect one of the most fundamental of all cosmological observables. One of the principal results of the present study was the conclusion that the evolution of spiral galaxies is almost independent of the global environment, especially for blue and red spirals separately, showing that the formation of spiral galaxies has to be similar in all environments. Meanwhile, the luminosity function of elliptical galaxies depends strongly on the environment. This shows that the global environmental density is an important factor (via merging history) in the formation of elliptical galaxies. The results of the present study show clearly, that besides the local/group environment, the global (supercluster-void) environment plays also an important role in the formation and evolution of galaxies. Accounting for the role of global environment can help to solve several problems in the present picture of galaxy formation and evolution.

  15. Illiteracy, Sex and Occupational Status in Present-Day China.

    ERIC Educational Resources Information Center

    Lamontagne, Jacques

    This study determined the magnitude of disparity between men and women in China in relation to illiteracy and occupational status. Region and ethnicity are used as control variables. The data collected are from a 10 percent sampling of the 1982 census; the total sample size includes a population of 100,380,000 nationwide. The census questionnaire…

  16. Likelihood of nitrogen condensation in Titan's present-day atmosphere

    NASA Astrophysics Data System (ADS)

    Tokano, Tetsuya

    2016-04-01

    The temperature in Titan's upper troposphere measured by the Huygens Probe is relatively close to the nitrogen condensation point. This poses the question as to whether seasonal nitrogen condensation might occur on Titan analogously to seasonal carbon dioxide condensation on Mars. The likelihood of nitrogen condensation in Titan's atmosphere is investigated using tropospheric temperature data obtained by Cassini radio occultations and simulation with a general circulation model (GCM). The observed tropospheric temperature generally decreases towards both poles but does not reach the nitrogen condensation point anywhere. However, Cassini may not have sounded the coldest season and area in Titan's troposphere. The GCM simulation shows that in the upper troposphere the variable solar distance associated with Saturn's orbital eccentricity has a larger impact on the seasonal polar temperature variation than the variable solar declination associated with Saturn's obliquity. In the upper troposphere relevant for nitrogen condensation the annual minimum polar temperature is predicted to occur around the northern autumnal equinox, approximately one season after aphelion. This temperature is then 1-2 K lower than in the season of the Cassini/Huygens mission. It is possible if not certain that some nitrogen condensation with cloud formation occurs in the northern and southern polar region in the upper troposphere around the northern autumnal equinox. Under the present orbital parameters of Saturn and Titan nitrogen condensation may occur more frequently near the south pole than near the north pole.

  17. Active Immunization—Some Present-Day Problems

    PubMed Central

    1941-01-01

    Diphtheria.—Immunization is safe and effective. Compulsory measures are indicated, especially for the younger age-groups. The Schick test may be reserved for selected groups and to control modified methods. Proper spacing of doses of prophylactics and periodic reinoculation will ensure a high level of immunity. It is important to beware of “one-shot” methods. Indiscriminate swabbing is to be discouraged; high carrier rates are an indication for widespread diphtheria prophylaxis. Enteric fever.—Mass immunization is desirable in many areas, although there is no justification for compulsion except for people exposed to special risks. In deciding upon dosage of vaccine, more attention should be paid to physical state and body-weight. After the primary course, very small periodic doses (for example o.i.c.c) are worthy of trial. Vaccine can be given during an epidemic without increasing the chances of infection. Tetanus.—Two doses of toxoid spaced by six weeks give useful immunity. Women give significantly higher titres than men. A third dose of i.o.c.c. after a long interval—seven to nine months—often produces a dramatic rise in circulating antitoxin, and counteracts any tendency to waning immunity. Smallpox.—As vaccination has not been made compulsory in this country, infection by virulent strains from the continent may tax the resources of the public health services. Whooping-cough.—The large number of injections of vaccine usually recommended is a deterrent to mass immunization. Research into the possibility of fewer doses and wider spacing is indicated. Other diseases are considered briefly. Combined immunization.—It may be useful to combine diphtheria T.A.F. and tetanus toxoid, also tetanus toxoid and T.A.B. vaccine. T.A.F. plus T.A.B. is probably contra-indicated for adults on account of severe reactions. Diphtheria A.P.T. should not be mixed with tetanus toxoid as it may go into solution and become ineffective. Sterilization of syringes and needles.—An intensive inoculation campaign is no excuse for slip-shod methods. PMID:19992328

  18. Microplate model for the present-day deformation of Tibet

    USGS Publications Warehouse

    Thatcher, W.

    2007-01-01

    Site velocities from 349 Global Positioning System (GPS) stations are used to construct an 11-element quasi-rigid block model of the Tibetan Plateau and its surroundings. Rigid rotations of five major blocks are well determined, and average translation velocities of six smaller blocks can be constrained. Where data are well distributed the velocity field can be explained well by rigid block motion and fault slip across block boundaries. Residual misfits average 1.6 mm/yr compared to typical one standard deviation velocity uncertainties of 1.3 mm/yr. Any residual internal straining of the blocks is small and heterogeneous. However, residual substructure might well represent currently unresolved motions of smaller blocks. Although any smaller blocks must move at nearly the same rate as the larger blocks within which they lie, undetected relative motions between them could be significant, particularly where there are gaps in GPS coverage. Predicted relative motions between major blocks agree with the observed sense of slip and along-strike partitioning of motion across major faults. However, predicted slip rates across Tibet's major strike-slip faults are low, only 5-12 mm/yr, a factor of 2-3 smaller than most rates estimated from fault offset features dated by radiometric methods as ???2000 to ???100,000 year old. Previous work has suggested that both GPS data and low fault slip rates are incompatible with rigid block motions of Tibet. The results reported here overcome these objections.

  19. Genetic structure and forensic parameters of 38 Indels for human identification purposes in eight Mexican populations.

    PubMed

    Martínez-Cortés, G; Gusmão, L; Pereira, R; Salcido, V H; Favela-Mendoza, A F; Muñoz-Valle, J F; Inclán-Sánchez, A; López-Hernández, L B; Rangel-Villalobos, H

    2015-07-01

    Insertion-deletions for human identification purposes (HID-Indels) offer advantages to solve particular forensic situations and complex paternity cases. In Mexico, admixed population known as Mestizos is the largest (∼90%), plus a number of Amerindian groups (∼10%), which have not been studied with HID-Indels. For this reason, allele frequencies and forensic parameters for 38 HID-Indels were estimated in 531 unrelated individuals from one Amerindian (Purépecha) and seven Mestizo populations from different regions of the country. Genotype distribution was in agreement with Hardy-Weinberg expectations in almost all loci/populations. The linkage disequilibrium (LD) test did not reveal possible associations between loci pairs in all eight Mexican populations. The combined power of discrimination was high in all populations (PD >99.99999999998%). However, the power of exclusion of the 38 HID-Indel system (PE >99.6863%) was reduced regarding most of autosomal STR kits. The assessment of genetic structure (AMOVA) and relationships between populations (FST) demonstrated significant differences among Mexican populations, mainly of the Purépecha Amerindian group. Among Mexican-Mestizos, three population clusters consistent with geography were defined: (i) North-West region: Chihuahua, Sinaloa, and Jalisco; (ii) Central-Southern region: Mexico City, Veracruz and Yucatan; (iii) South region: Chiapas. In brief, this report validates the inclusion of the 38 HID-Indel system in forensic casework and paternity cases in seven Mexican-Mestizo populations from different regions, and in one Mexican Amerindian group.

  20. A/G Gln20Arg (exon 1) and G/A Val156Met (exon 5) polymorphisms of the human orosomucoid 1 gene in Mexico.

    PubMed

    García-Ortiz, L; Vargas-Alarcón, G; Fragoso, J M; Granados, J; Maldonado Noriega, L; Navas Pérez, A; Huerta Reyes, E; Zenteno-Ruiz, J C; Martínez-Cordero, E

    2008-01-08

    The human orosomucoid 1 gene (ORM1) codes an alpha-1-acid glycoprotein that has been classified as an acute-phase reactive protein, and a major drug-binding serum component, as well as an immunomodulatory protein with genetic polymorphisms. Evaluation of ORM variation through isoelectric focusing and immunobloting has revealed a world-wide distribution of the ORM1 F and ORM1 S alleles. We evaluated and examined the genetic characteristics of two Mexican populations that have different anthropological and cultural antecedents, examining two ORM1 genotypes (exon 1 - A/G (Gln20Arg) and exon 5 G/A (Val156Met)) in 145 individuals, using nested polymerase chain reaction, sequencing, and restricted fragment length polymorphism. Mexican Mestizos had higher frequencies of the exon 1 A allele (P = 0.020) and AA genotype (P = 0.018) and lower frequency of the G allele (P = 0.020) when compared to Teenek Amerindians. When we examined exon 5 G/A (Val156Met) polymorphisms, we found significantly higher frequencies of the G allele (P = 0.0007) and the GG genotype (P = 0.0003) in the Mexican Mestizo population. The Teenek population had a significantly higher frequency of the A allele than has been reported for Chinese and African (P < 0.05) populations, and the G/A genotype was more frequently found in this Mexican population than in Chinese, African and European populations (P < 0.05).

  1. Mammalian phylogeny reveals recent diversification rate shifts.

    PubMed

    Stadler, Tanja

    2011-04-12

    Phylogenetic trees of present-day species allow investigation of the rate of evolution that led to the present-day diversity. A recent analysis of the mammalian phylogeny challenged the view of explosive mammalian evolution after the Cretaceous-Tertiary (K/T) boundary (65 Mya). However, due to lack of appropriate methods, the diversification (speciation minus extinction) rates in the more recent past of mammalian evolution could not be determined. In this paper, I provide a method that reveals that the tempo of mammalian evolution did not change until ∼ 33 Mya. This constant period was followed by a peak of diversification rates between 33 and 30 Mya. Thereafter, diversification rates remained high and constant until 8.55 Mya. Diversification rates declined significantly at 8.55 and 3.35 Mya. Investigation of mammalian subgroups (marsupials, placentals, and the six largest placental subgroups) reveals that the diversification rate peak at 33-30 Mya is mainly driven by rodents, cetartiodactyla, and marsupials. The recent diversification rate decrease is significant for all analyzed subgroups but eulipotyphla, cetartiodactyla, and primates. My likelihood approach is not limited to mammalian evolution. It provides a robust framework to infer diversification rate changes and mass extinction events in phylogenies, reconstructed from, e.g., present-day species or virus data. In particular, the method is very robust toward noise and uncertainty in the phylogeny and can account for incomplete taxon sampling. PMID:21444816

  2. Revealing Mercury

    NASA Astrophysics Data System (ADS)

    Prockter, L. M.; Solomon, S. C.; Head, J. W.; Watters, T. R.; Murchie, S. L.; Robinson, M. S.; Chapman, C. R.; McNutt, R. L.

    2009-04-01

    The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, developed under NASA's Discovery Program, launched in August 2004. En route to insertion into orbit about Mercury in 2011, MESSENGER flies by Mercury three times. The first and second of these encounters were accomplished in January and October of 2008. These flybys viewed portions of Mercury's surface that were not observed by Mariner 10 during its reconnaissance of somewhat less than half of the planet in 1974-1975. All MESSENGER instruments operated during each flyby and returned a wealth of new data. Many of the new observations were focused on the planet's geology, including monochrome imaging at resolutions as high as 100 m/pixel, multispectral imaging in 11 filters at resolutions as high as 500 m/pixel, laser altimetry tracks extending over several thousands of kilometers, and high-resolution spectral measurements of several types of terrain. Here we present an overview of the first inferences on the global geology of Mercury from the MESSENGER observations. Whereas evidence for volcanism was equivocal from Mariner 10 data, the new MESSENGER images and altimetry provide compelling evidence that volcanism was widespread and protracted on Mercury. Color imaging reveals three common spectral units on the surface: a higher-reflectance, relatively red material occurring as a distinct class of smooth plains, typically with distinct embayment relationships interpreted to indicate volcanic emplacement; a lower-reflectance, relatively blue material typically excavated by impact craters and therefore inferred to be more common at depth; and a spectrally intermediate terrain that constitutes much of the uppermost crust. Three more minor spectral units are also seen: fresh crater ejecta, reddish material associated with rimless depressions interpreted to be volcanic centers, and high-reflectance deposits seen in some crater floors. Preliminary measurements of crater size

  3. Genetic variation among four Mexican populations (Huichol, Purepecha, Tarahumara, and Mestizo) revealed by two VNTRs and four STRs.

    PubMed

    Rangel-Villalobos, H; Rivas, F; Sandoval, L; Ibarra, B; Garcìa-Carvajal, Z Y; Cantú, J M; Figuera, L E

    2000-12-01

    Allele distributions of two polymorphisms with variable number of tandem repeats (VNTR), D1S80 and APOB, and four polymorphisms with short tandem repeats (STR), VWA, TH01, CSF1PO, and HPRTB, were analyzed in three Mexican ethnic groups: Huichol, Purepecha, and Tarahumara. Genotype distribution was in agreement with Hardy-Weinberg expectations for each locus and ethnic group. Heterozygosity (H), power of discrimination, and probability of exclusion were estimated. The three groups presented some distinctive genetic features: (1) a diminished genetic diversity (H = 66.8% to 73.4%) and mean number of alleles by locus (5.8 to 6.3) in comparison with Mexican mestizos (H = 78.3%, 10.5 alleles/locus), and (2) uneven allele distributions as evidenced by "distinctive alleles" with high frequencies, especially in the Tarahumara and the Huichol. Genetic relatedness analysis included data from a previously typed mestizo population, the largest and most widely distributed population in Mexico. Allele distribution differentiation was observed among all four groups, except between mestizo and Purepecha (p > 0.05), which was interpreted as indicating a larger Spanish component in the Purepecha as a result of gene flow effects. Although intrapopulation inbreeding (FIS) was not significant, heterozygote deficiency in the total population (FIT) and divergence among populations (FST) were significant (p < 0.05). Genetic distances displayed a closer relationship among mestizos, Purepechas, and Huichols in relation to Tarahumaras. Correlation between the observed genetic features and the geographic isolation level points to genetic drift as the main cause of differentiation among these Mexican populations.

  4. Impact of road traffic emissions on tropospheric ozone in Europe for present day and future scenarios

    NASA Astrophysics Data System (ADS)

    Mertens, Mariano; Kerkweg, Astrid; Grewe, Volker; Jöckel, Patrick

    2016-04-01

    Road traffic is an important anthropogenic source of NOx, CO and non-methane hydrocarbons (NMHCs) which act as precursors for the formation of tropospheric ozone. The formation of ozone is highly non-linear. This means that the contribution of the road traffic sector cannot directly be derived from the amount of emitted species, because they are also determined by local emissions of other anthropogenic and natural sources. In addition, long range transport of precursors and ozone can play an important role in determining the local ozone budget. For a complete assessment of the impact of road traffic emissions it is therefore important to resolve both, local emissions and long range transport. This can be achieved by the use of the newly developed MECO(n) model system, which on-line couples the global chemistry-climate-model EMAC with the regional chemistry-climate-model COSMO-CLM/MESSy. Both models use the same chemical speciation. This allows a highly consistent model chain from the global to the local scale. To quantify the contribution of the road traffic emissions to tropospheric ozone we use an accounting system of the relevant reaction pathways of the different species from different sources (called tagging method). This tagging scheme is implemented consistently on all scales, allowing a direct comparison of the contributions. With this model configuration we investigate the impact of road traffic emissions to the tropospheric ozone budget in Europe. For the year 2008 we compare different emission scenarios and investigate the influence of both model and emission resolution. In addition, results of a mitigation scenario for the year 2030 are presented. They indicate that the contribution of the road traffic sector can be reduced by local reductions of emissions during summer. During winter the importance of long range transport increases. This can lead to increased contributions of the road traffic sector (e.g. by increased emissions in the US) even if local emissions are reduced.

  5. Present-day formation and seasonal evolution of linear dune gullies on Mars

    NASA Astrophysics Data System (ADS)

    Pasquon, Kelly; Gargani, Julien; Massé, Marion; Conway, Susan J.

    2016-08-01

    Linear dune gullies are a sub-type of martian gullies. As their name suggests they only occur on sandy substrates and comprise very long (compared to their width) straight or sinuous channels, with relatively small source areas and almost non-existent visible deposits. Linear dune gullies have never been observed on terrestrial dunes and their formation process on Mars is unclear. Here, we present the results of the first systematic survey of these features in Mars' southern hemisphere and an in-depth study of six dunefields where repeat-imaging allows us to monitor the changes in these gullies over time. This study was undertaken with HiRISE images at 25-30 cm/pix and 1 m/pix elevation data derived from HiRISE stereo images. We find the latitudinal distribution and orientation of linear dune gullies broadly consistent with the general population of martian gullies. They occur predominantly between 36.3°S and 54.3°S, and occasionally between 64.6°S and 70.4°S. They are generally oriented toward SSW (at bearings between 150° and 260°). We find that these gullies are extremely active over the most recent 5 Martian years of images. Activity comprises: (1) appearance of new channels, (2) lengthening of existing channels, (3) complete or partial reactivation, and (4) disappearance of gullies. We find that gully channels lengthen by ∼100 m per year. The intense activity and the progressive disappearance of linear dune gullies argues against the hypothesis that these are remnant morphologies left over from previous periods of high obliquity millions of years ago. The activity of linear dune gullies reoccurs every year between the end of winter and the beginning of spring (Ls 167.4°-216.6°), and coincides with the final stages of the sublimation of annual CO₂ ice deposit. This activity often coincides spatially and temporally with the appearance of recurrent diffusing flows (RDFs)-digitate-shaped, dark patches with low relative albedo (up to 48% lower than the adjacent dune) that encompass the active site. South- and SSW-facing dune slopes are those which preferentially host CO2 frost deposits, however, it is only those with angles of ∼20° just below the crest which possess linear dune gullies, suggesting a slope-limited formation process. These observations provide a wealth of temporal and morphometric data that can be used to undertake numerical modeling, to direct future image monitoring and guide laboratory experiments that can be used to better constrain the formation process of these features.

  6. Present-day star formation: From molecular cloud cores to protostars and protoplanetary disks

    NASA Astrophysics Data System (ADS)

    Inutsuka, Shu-ichiro

    2012-10-01

    Essential physical processes in the formation of protostars and protoplanetary disks are described. Recent advances in non-ideal magnetohydrodynamics simulations, which cover a huge dynamic range from molecular cloud core density (104/cc) to stellar density (1022/cc) in a self-consistent manner, enable us to study the realistic evolution of the magnetic field and rotation of protostars and the dynamics of outflows and jets. First we emphasize the importance of radiative heating and cooling, and describe thermal evolution in a self-gravitationally collapsing cloud. The increased pressure at the center creates the first hydrostatic core, which consists of molecular gas. After the dissociation of molecular hydrogen triggers the second gravitational collapse at the center of the first core, a protostar is quickly formed and the first core gradually transforms into a circumstellar disk that eventually accretes onto the central protostar. The importance of the short-lived first core formed in the early collapsing phase is emphasized in the contexts of driving magnetohydrodynamical bipolar outflows and self-gravitational fragmentation into binary or multiple stars. When the central density becomes sufficiently high (1012/cc), ohmic dissipation largely removes the magnetic flux from a collapsing cloud core, and the strongly twisted magnetic field lines are straightened. The magnetic field lines are twisted and amplified again for much higher density (1016/cc) where the magnetic field is recoupled with warm gas (˜103 K). Finally, protostars at their formation epoch have magnetic fields of 0.1-1 kG, which is comparable to observed values of pre-main-sequence stars. A substantially reduced magnetic flux at the center results in passively wound-up magnetic field lines just after the formation of a protostar. This is followed by driving of a fast bipolar jet along the rotation axis by the resultant magnetic pressure due to excessive winding. Strong collimation of the jet is due to the hoop stress of piled-up toroidal field lines. The angular momentum in a collapsing cloud is removed by magnetohydrodynamical effects such as magnetic braking and driving of outflows and jets. The rotation velocity of the protostar tends to be on the order of break-up speed at its formation epoch, and thus, a further removal mechanism for the angular momentum, such as through the interactions between the protostar, disk, jets, and winds, should be important in its long-term evolution. The circumstellar disk is born in the "dead zone," a region that is decoupled from the magnetic field. The outer radius of the disk increases with that of the dead zone during accretion from the envelope of the molecular cloud core. A rapid increase in the disk size occurs after depletion of the envelope. The circumstellar disks remain massive in their formation phase, and are subject to gravitational instability, even at 10 AU from the central stars. The further long-term evolution of massive disks is also described. This may provide an improved description for the realistic initial condition and environments for planet formation in gaseous protoplanetary disks.

  7. [From Leonardo Da Vinci to present days; from the history of antiplague costume].

    PubMed

    Kalmykov, A A; Aminev, R M; Korneev, A G; Polyakov, V S; Artebyakin, S V

    2016-01-01

    As a prototype of the antiplague costume can be considered a special clothing, which physicians in medieval Europe wear for protection in plague nidus. Inventor of the first antiplague costume is considered to be a French doctor Charles de Lorme (1619). Much later, in 1878, a Russian professor Pashutin V V offered to use a costume, which looked like a hermetically sealed "bag" with a special breathing device aimed at protection of medical staff. Later, professor O.I. Dogel's respirator became well-known (1889). At the beginning of 20th century as part of the antiplague costume was used a charcoal filter mask, invented by Zelinsky N.D. Requirements to order the use of modern means of individual protection when working in nidus of especially dangerous infections identified sanitary-epidemiological rules, which reflect issues of laboratory workers working and protective clothing, respiratory protection, and view, especially operation, the procedure of putting on, removing and disinfecting antiplague costumes, pneumocostumes, pneumohelmets, isolation suits, gas-protection boxes, etc. PMID:27120957

  8. Mercury's interior structure constrained by geodesy and present-day thermal state

    NASA Astrophysics Data System (ADS)

    Rivoldini, Attilio; Van Hoolst, Tim; Beuthe, Mikael; Deproost, Marie-Hélène

    2016-10-01

    Recent measurements of Mercury's spin state and gravitational field strongly constrain Mercury's core radius and core density, but provide little information on the size of its inner core. Both a fully molten liquid core and a core differentiated into a large solid inner core and a liquid outer part are consistent with the observations, although the observed tides seem to exclude an extremely large inner core. The observed global magnetic field could be generated even without a growing inner core, since remelting of iron snow inside the core might produce a sufficiently large buoyancy flux to drive magnetic field generation by compositional convection.Further constraints on Mercury's internal structure can be obtained by studying its thermal state. The inner core radius depends mainly on the thermal state and on the light elements present in the core. Secular cooling and subsequent formation of an inner core lead to the global contraction of the planet, estimated to be about 7 km.In this study we combine geodesy data (88 day libration amplitude, polar moment of inertia, and tidal Love number) with the recent estimate of the radial contraction of Mercury and thermal evolution calculations in order to constrain its interior structure and in particular its inner core. We consider bulk compositions that are in agreement with the reducing formation conditions suggested by remote sensing data of Mercury's surface.

  9. Present-day Crustal Deformation and Neotectonics in Northern Hualien, Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, C.; Lee, J.; Chen, R.; Chen, Y.

    2008-12-01

    Eastern Taiwan has long been well-known as the collision suture between the Eurasian plate and the Philippine Sea plate and thus characterized by dense earthquakes and active faults. Hualien is located at the transition point where the Philippine Sea plate westward obducts upon the Eurasian plate in the south, while dives under the Eurasian plate from the latitude of Hualien northwards. Two active structures have been reported in Hualien area. One is the Milun thrust fault, the surface rupture of 1951 M=7.1 Hualien earthquake. It has been mapped running through the city of Hualien, showing coseismic slips of 1.2 and 2 m for its vertical and sinistral strike slip respectively. The second one is the Beipu structure identified by relevant geomorphic features. This study used Taiwan 40m-DTM to identify the coverage of above two structure related geomorphic features and further used RTK-GPS to construct high-resolution topography for the detailed analyses. A dense network of GPS is also deployed to monitor recent horizontal crustal displacement. The D-InSAR is additionally applied to target on recent vertical displacement. The GPS results show that Hualien area moves northwestward relative to the stable reference of the station S01R at Penghu, located in Taiwan Strait. Our GPS results demonstrate the hanging wall of the Milun fault is moving northward faster than the footwall with a left-lateral strike slip. This implies this fault acts as an oblique thrust fault in both of the interseismic and coseismic period. On the other hand, by characterized topography shape the Beipu structure can be interpreted as a flower structure consistent with left-lateral en echelon array. To our surprise, the GPS velocities show a possible left-lateral but extensional movement in Beipu area. Our D-InSAR results show uneven vertical displacements in the study area, but still can see hanging wall of the Meilun fault is uplifting relative to its footwall.

  10. Modelling the nebular emission from primeval to present-day star-forming galaxies

    NASA Astrophysics Data System (ADS)

    Gutkin, Julia; Charlot, Stéphane; Bruzual, Gustavo

    2016-10-01

    We present a new model of the nebular emission from star-forming galaxies in a wide range of chemical compositions, appropriate to interpret observations of galaxies at all cosmic epochs. The model relies on the combination of state-of-the-art stellar population synthesis and photoionization codes to describe the ensemble of H II regions and the diffuse gas ionized by young stars in a galaxy. A main feature of this model is the self-consistent yet versatile treatment of element abundances and depletion on to dust grains, which allows one to relate the observed nebular emission from a galaxy to both gas-phase and dust-phase metal enrichment. We show that this model can account for the rest-frame ultraviolet and optical emission-line properties of galaxies at different redshifts and find that ultraviolet emission lines are more sensitive than optical ones to parameters such as C/O abundance ratio, hydrogen gas density, dust-to-metal mass ratio and upper cut-off of the stellar initial mass function. We also find that, for gas-phase metallicities around solar to slightly subsolar, widely used formulae to constrain oxygen ionic fractions and the C/O ratio from ultraviolet and optical emission-line luminosities are reasonable faithful. However, the recipes break down at non-solar metallicities, making them inappropriate to study chemically young galaxies. In such cases, a fully self-consistent model of the kind presented in this paper is required to interpret the observed nebular emission.

  11. Modeling soluble salt assemblages on Mars: past aqueous history and present-day habitability

    NASA Astrophysics Data System (ADS)

    Toner, J. D.; Catling, D. C.; Light, B.

    2014-12-01

    Soluble salt assemblages formed through aqueous processes are widespread on Mars. These minerals are important for understanding the past aqueous history of Mars and indicate critical habitability parameters such as pH, temperature, water activity, and salinity. Equilibrium models have been used to determine solution chemistry and salt precipitation sequences from aqueous chemical data; however, current models are limited by a lack of experimental data for low-temperature perchlorates, and some model predictions are clearly anomalous. To address the need for accurate equilibrium models, we have developed a comprehensive model for low-temperature perchlorate-rich brines using (1) previously neglected literature data, (2) experimental solubilities determined in low-temperature perchlorate solutions, and (3) solubility and heat capacity results determined using Differential Scanning Calorimetry (DSC). Our resulting model is a significant improvement over existing models, such as FREZCHEM, particularly for perchlorate mixtures. We have applied our model to evaporation and freezing of a nominal Wet Chemistry Laboratory (WCL) solution measured at the Phoenix site. For a freezing WCL solution, our model indicates that ice, KClO4, hydromagnesite (3MgCO3·Mg(OH)2·3H2O), calcite (CaCO3), meridianiite (MgSO4·11H2O), MgCl2·12H2O, NaClO4·2H2O, and Mg(ClO4)2·6H2O form at the eutectic (209 K); whereas, KClO4, hydromagnesite, kieserite (MgSO4·H2O), anhydrite (CaSO4), halite (NaCl), NaClO4·H2O, and Mg(ClO4)2·6H2O form upon complete evaporation at 298 K. In general, evaporation yields more dehydrated mineral assemblages than salts produced by freezing. Hydrated phases that form during evaporation contain 0.3 wt. % water, which compares with 1.2 wt. % during freezing. Given independent evidence for the presence of calcite and minimum water contents in Martian soils of ~1.5 wt. %, salts at the Phoenix site, and possibly elsewhere, appear more likely to have formed during freezing. Furthermore, our model indicates that some minerals, such as halite, kieserite, epsomite, and mirabilite (Na2SO4·10H2O) form only under limited temperature and water activity conditions, and could be used to constrain the past aqueous history of Mars.

  12. A historical perspective on protein crystallization from 1840 to the present day.

    PubMed

    Giegé, Richard

    2013-12-01

    Protein crystallization has been known since 1840 and can prove to be straightforward but, in most cases, it constitutes a real bottleneck. This stimulated the birth of the biocrystallogenesis field with both 'practical' and 'basic' science aims. In the early years of biochemistry, crystallization was a tool for the preparation of biological substances. Today, biocrystallogenesis aims to provide efficient methods for crystal fabrication and a means to optimize crystal quality for X-ray crystallography. The historical development of crystallization methods for structural biology occurred first in conjunction with that of biochemical and genetic methods for macromolecule production, then with the development of structure determination methodologies and, recently, with routine access to synchrotron X-ray sources. Previously, the identification of conditions that sustain crystal growth occurred mostly empirically but, in recent decades, this has moved progressively towards more rationality as a result of a deeper understanding of the physical chemistry of protein crystal growth and the use of idea-driven screening and high-throughput procedures. Protein and nucleic acid engineering procedures to facilitate crystallization, as well as crystallization methods in gelled-media or by counter-diffusion, represent recent important achievements, although the underlying concepts are old. The new nanotechnologies have brought a significant improvement in the practice of protein crystallization. Today, the increasing number of crystal structures deposited in the Protein Data Bank could mean that crystallization is no longer a bottleneck. This is not the case, however, because structural biology projects always become more challenging and thereby require adapted methods to enable the growth of the appropriate crystals, notably macromolecular assemblages.

  13. Geochemistry and geobiology of a present-day serpentinization site in California: The Cedars

    NASA Astrophysics Data System (ADS)

    Morrill, Penny L.; Kuenen, J. Gijs; Johnson, Orion J.; Suzuki, Shino; Rietze, Amanda; Sessions, Alex L.; Fogel, Marilyn L.; Nealson, Kenneth H.

    2013-05-01

    Ultra-basic (pH 11-12) reducing (-656 to -585 mV) groundwater springs discharging from serpentinized peridotite of The Cedars, CA, were investigated for their geochemistry and geobiology. The spring waters investigated were of meteoric origin; however, geochemical modeling suggests that there were two sources of groundwater, a shallow source with sufficient contact with The Cedars' peridotite body to be altered geochemically by serpentinization, and a deeper groundwater source that not only flows through the peridotite body but was also in contact with the marine sediments of the Franciscan Subduction Complex (FSC) below the peridotite body. We propose that the groundwater discharging from lower elevations (GPS1 and CS1) reflect the geochemistry of the deeper groundwater in contact with FSC, while groundwaters discharging from springs at higher elevations (NS1 and BSC) were a mixture of the shallow peridotite-only groundwater and the deeper groundwater that has been in contact with the FSC. Cell densities of suspended microbes within these waters were extremely low. In the NS1 and BSC spring fluids, cell densities ranged from 102 to 103 cells/ml, while suspended cells at GPS were lower than 10 cells/mL. However, glass slides incubated in the BSC and GPS1 springs for 2-3 weeks were colonized by cells with densities ranging from 106 to 107 cells/cm2 attached to their surfaces. All of the springs were very low (⩽1 μM) in several essential elements and electron acceptors (e.g. nitrate/ammonium, sulfate, and phosphate) required for (microbial) growth, which is not uncommon at sites of continental serpentinization. Gases rich in N2, H2, and CH4 were exsolving from the springs. The stable carbon isotope value (δ13CCH4 = -68 ± 0.6‰) and the CH4/C2+ (>103) of methane and other gaseous hydrocarbons exsolving from NS1 were typical of microbially sourced methane, whereas the isotope values and the CH4/C2+ of BSC and CS1 springs were more enriched in 13C and had CH4/C2+ < 103, suggesting a mixture of microbial and non-microbial methane. The concentrations of aromatic compounds, and ethane, propane, iso- and n-butane were well described by simple physical mixing between the aromatic- and alkane-poor, shallow groundwater and the relatively aromatic, and alkane-rich groundwater that flows through both the peridotite and the FSC suggesting that these aromatic and alkane compounds originated in the deeper FSC groundwater and are not produced in the shallow peridotite-only groundwater. The aromatic compounds most probably originated from the diagenesis/degradation of organic matter in the marine sediments below the peridotite body, while the gaseous alkanes may have multiple sources including thermal degradation of the organic matter in the marine sediments below the peridotite body and possibly by abiogenic reactions occurring within the peridotite body. This geochemical study demonstrates the complexity of The Cedars, and the possible sources of hydrocarbons at continental sites of serpentinization.

  14. Independent Review of Simulation of Net Infiltration for Present-Day and Potential Future Climates

    SciTech Connect

    Review Panel: Soroosh Sorooshian, Ph.D., Panel Chairperson, University of California, Irvine; Jan M. H. Hendrickx, Ph.D., New Mexico Institute of Mining and Technology; Binayak P. Mohanty, Ph.D., Texas A&M University; Scott W. Tyler, Ph.D., University of Nevada, Reno; Tian-Chyi Jim Yeh, Ph.D., University of Arizona -- ORISE Review Facilitators: Robert S. Turner, Ph.D., Technical Review Group Manager, Oak Ridge Institute for Science and Education; Brian R. Herndon, Project Manager, Oak Ridge Institute for Science and Education; Russ Manning, Technical Writer /Editor, Haselwood Enterprises, Inc.

    2008-08-30

    The DOE Office of Civilian Radioactive Waste Management (OCRWM) tasked Oak Ridge Institute for Science and Education (ORISE) with providing an independent expert review of the documented model and prediction results for net infiltration of water into the unsaturated zone at Yucca Mountain. The specific purpose of the model, as documented in the report MDL-NBS-HS-000023, Rev. 01, is “to provide a spatial representation, including epistemic and aleatory uncertainty, of the predicted mean annual net infiltration at the Yucca Mountain site ...” (p. 1-1) The expert review panel assembled by ORISE concluded that the model report does not provide a technically credible spatial representation of net infiltration at Yucca Mountain. Specifically, the ORISE Review Panel found that: • A critical lack of site-specific meteorological, surface, and subsurface information prevents verification of (i) the net infiltration estimates, (ii) the uncertainty estimates of parameters caused by their spatial variability, and (iii) the assumptions used by the modelers (ranges and distributions) for the characterization of parameters. The paucity of site-specific data used by the modeling team for model implementation and validation is a major deficiency in this effort. • The model does not incorporate at least one potentially important hydrologic process. Subsurface lateral flow is not accounted for by the model, and the assumption that the effect of subsurface lateral flow is negligible is not adequately justified. This issue is especially critical for the wetter climate periods. This omission may be one reason the model results appear to underestimate net infiltration beneath wash environments and therefore imprecisely represent the spatial variability of net infiltration. • While the model uses assumptions consistently, such as uniform soil depths and a constant vegetation rooting depth, such assumptions may not be appropriate for this net infiltration simulation because they oversimplify a complex landscape and associated hydrologic processes, especially since the model assumptions have not been adequately corroborated by field and laboratory observations at Yucca Mountain.

  15. Notoriety to respectability: a short history of arsenic prior to its present day use in haematology.

    PubMed

    Doyle, Derek

    2009-05-01

    This paper looks at arsenic, and in particular the trioxide, from the days of the ancient Chinese, Egyptians, Greeks and Romans, through the 17th-20th centuries to its adoption by today's haematologists. It looks at its commercial and medical uses, past and present, its notoriety as a poison, it's reputation as a 'tonic' and therapeutic agent, many of the famous people associated with it including Thomas Fowler, William Withering and Robert Christison, and the promise an 18th century panacea now offers 21st century patients under the care of today's haematologists and tomorrow's oncologists.

  16. Ancient human genomes suggest three ancestral populations for present-day Europeans

    PubMed Central

    Lazaridis, Iosif; Patterson, Nick; Mittnik, Alissa; Renaud, Gabriel; Mallick, Swapan; Kirsanow, Karola; Sudmant, Peter H.; Schraiber, Joshua G.; Castellano, Sergi; Lipson, Mark; Berger, Bonnie; Economou, Christos; Bollongino, Ruth; Fu, Qiaomei; Bos, Kirsten I.; Nordenfelt, Susanne; Li, Heng; de Filippo, Cesare; Prüfer, Kay; Sawyer, Susanna; Posth, Cosimo; Haak, Wolfgang; Hallgren, Fredrik; Fornander, Elin; Rohland, Nadin; Delsate, Dominique; Francken, Michael; Guinet, Jean-Michel; Wahl, Joachim; Ayodo, George; Babiker, Hamza A.; Bailliet, Graciela; Balanovska, Elena; Balanovsky, Oleg; Barrantes, Ramiro; Bedoya, Gabriel; Ben-Ami, Haim; Bene, Judit; Berrada, Fouad; Bravi, Claudio M.; Brisighelli, Francesca; Busby, George B. J.; Cali, Francesco; Churnosov, Mikhail; Cole, David E. C.; Corach, Daniel; Damba, Larissa; van Driem, George; Dryomov, Stanislav; Dugoujon, Jean-Michel; Fedorova, Sardana A.; Romero, Irene Gallego; Gubina, Marina; Hammer, Michael; Henn, Brenna M.; Hervig, Tor; Hodoglugil, Ugur; Jha, Aashish R.; Karachanak-Yankova, Sena; Khusainova, Rita; Khusnutdinova, Elza; Kittles, Rick; Kivisild, Toomas; Klitz, William; Kučinskas, Vaidutis; Kushniarevich, Alena; Laredj, Leila; Litvinov, Sergey; Loukidis, Theologos; Mahley, Robert W.; Melegh, Béla; Metspalu, Ene; Molina, Julio; Mountain, Joanna; Näkkäläjärvi, Klemetti; Nesheva, Desislava; Nyambo, Thomas; Osipova, Ludmila; Parik, Jüri; Platonov, Fedor; Posukh, Olga; Romano, Valentino; Rothhammer, Francisco; Rudan, Igor; Ruizbakiev, Ruslan; Sahakyan, Hovhannes; Sajantila, Antti; Salas, Antonio; Starikovskaya, Elena B.; Tarekegn, Ayele; Toncheva, Draga; Turdikulova, Shahlo; Uktveryte, Ingrida; Utevska, Olga; Vasquez, René; Villena, Mercedes; Voevoda, Mikhail; Winkler, Cheryl; Yepiskoposyan, Levon; Zalloua, Pierre; Zemunik, Tatijana; Cooper, Alan; Capelli, Cristian; Thomas, Mark G.; Ruiz-Linares, Andres; Tishkoff, Sarah A.; Singh, Lalji; Thangaraj, Kumarasamy; Villems, Richard; Comas, David; Sukernik, Rem; Metspalu, Mait; Meyer, Matthias; Eichler, Evan E.; Burger, Joachim; Slatkin, Montgomery; Pääbo, Svante; Kelso, Janet; Reich, David; Krause, Johannes

    2014-01-01

    We sequenced the genomes of a ~7,000 year old farmer from Germany and eight ~8,000 year old hunter-gatherers from Luxembourg and Sweden. We analyzed these and other ancient genomes1–4 with 2,345 contemporary humans to show that most present Europeans derive from at least three highly differentiated populations: West European Hunter-Gatherers (WHG), who contributed ancestry to all Europeans but not to Near Easterners; Ancient North Eurasians (ANE) related to Upper Paleolithic Siberians3, who contributed to both Europeans and Near Easterners; and Early European Farmers (EEF), who were mainly of Near Eastern origin but also harbored WHG-related ancestry. We model these populations’ deep relationships and show that EEF had ~44% ancestry from a “Basal Eurasian” population that split prior to the diversification of other non-African lineages. PMID:25230663

  17. Present-day biogeochemical activities of anaerobic bacteria and their relevance to future exobiological investigations

    USGS Publications Warehouse

    Oremland, R.S.

    1989-01-01

    If the primordial atmosphere was reducing, then the first microbial ecosystem was probably composed of anaerobic bacteria. However, despite the presence of an oxygen-rich atmosphere, anaerobic habitats are important, commonplace components of the Earth's present biosphere. The geochemical activities displayed by these anaerobes impact the global cycling of certain elements (e.g., C, N, S, Fe, Mn, etc.). Methane provides an obvious example of how human-enhanced activities on a global scale can influence the content of a "radiative" (i.e., infrared absorbing) trace gas in the atmosphere. Methane can be oxidized by anaerobic bacteria, but this does not appear to support their growth. Acetylene, however, does support such growth. This may form the basis for future exobiological investigations of the atmospheres of anoxic, hydrocarbon-rich planets like Jupiter and Saturn, as well as the latter's satellite Titan. ?? 1989.

  18. Climatology and temporal evolution of the atmospheric semidiurnal tide in present-day reanalyses

    NASA Astrophysics Data System (ADS)

    Díaz-Argandoña, J.; Ezcurra, A.; Sáenz, J.; Ibarra-Berastegi, G.; Errasti, I.

    2016-05-01

    The solar semidiurnal atmospheric tide (S2) was extracted from seven reanalysis data sets, including current data sets, such as CFSR (Climate Forecast System Reanalysis), MERRA (Modern-Era Retrospective Analysis for Research and Applications), ERA-Interim (ECMWF Reanalysis), and 20CR (Twentieth Century Reanalysis), and older frozen products, such as NCEP/NCAR (National Center for Environmental Prediction/National Center for Atmospheric Research), ERA-40 (ECMWF Reanalysis), and JRA-25 (Japanese 25 year Reanalysis). In this calculation, we emphasized the temporal variation of the tide. We also calculated the tidal error, which was sizable at high latitudes and over short averaging periods and large for 20CR at all latitudes. Because of the four standard daily samples, the interpolation scheme of van den Dool et al. (1997) was used when necessary. We found this method to be accurate for zonally averaged tides only. Comparing the climatology from the MERRA and CFSR S2 with a recent empirical tide model showed that MERRA better represented the geographical structure of the tide, especially its phase. We found a bias in the phase in all of the reanalysis data sets except for MERRA. The temporal evolution of the tide was inconsistent between the different data sets, although similar seasonal variations were observed. The seasonal cycle was also better depicted in MERRA. The S2 calculated from MERRA and satellite precipitation measurements from TRMM (Tropical Rainfall Measuring Mission) presented results that were inconsistent with the hypothesis in which rainfall latent heat release represents S2 forcing and functions as a source of S2 seasonal variability.

  19. Methodological Problems of the Present-Day Sociology of Education: A Roundtable

    ERIC Educational Resources Information Center

    Russian Education and Society, 2011

    2011-01-01

    An all-Russian conference on "Education and Society" was held on 22 October 2009 at the Academy of Labor and Social Relations, in the course of which roundtables were conducted with leading representatives of Russian sociological science. The conference was timed to coincide with the twentieth anniversary of the founding of the Russian Society of…

  20. Digitization of the human body in the present-day economy

    NASA Astrophysics Data System (ADS)

    D'Apuzzo, Nicola

    2004-12-01

    In this paper we report on the historic development of human body digitization and on the actual state of commercially available technology. Complete systems for the digitization of the human body exist since more than ten years. One of the main users of this technology was the entertainment industry. Every new movie excited with attractive visual effects, but only few people knew that the most thrilling cuts were realized by using virtual persons. The faces and bodies of actors were digitized and the "virtual twin" replaced the actor in the movie. Nowadays, the state of the human body digitization is so high that it is not possible any more to distinguish the real actor from the virtual one. Indeed, for the rush technical development has to be thanked the movie industry, which was one of the strong economic motors for this technology. Today, with the possibility of a massive cost reduction given by new technologies, methods for digitization of the human body are used also in other fields of application, such as ergonomics, medical applications, computer games, biometry and anthropometrics. With the time, this technology becomes interesting also for sport, fitness, fashion and beauty. A large expansion of human body digitization is expected in the near future. To date, different technologies are used commercially for the measurement of the human body. They can be divided into three distinguished groups: laser-scanning, projection of light patterns, combination modeling and image processing. The different solutions have strengths and weaknesses that profile their suitability for specific applications. This paper gives an overview of their differences and characteristics and expresses clues for the selection of the adequate method. Practical examples of commercial exploitation of human body digitization are also presented and new interesting perspectives are introduced.

  1. Digitization of the human body in the present-day economy

    NASA Astrophysics Data System (ADS)

    D'Apuzzo, Nicola

    2005-01-01

    In this paper we report on the historic development of human body digitization and on the actual state of commercially available technology. Complete systems for the digitization of the human body exist since more than ten years. One of the main users of this technology was the entertainment industry. Every new movie excited with attractive visual effects, but only few people knew that the most thrilling cuts were realized by using virtual persons. The faces and bodies of actors were digitized and the "virtual twin" replaced the actor in the movie. Nowadays, the state of the human body digitization is so high that it is not possible any more to distinguish the real actor from the virtual one. Indeed, for the rush technical development has to be thanked the movie industry, which was one of the strong economic motors for this technology. Today, with the possibility of a massive cost reduction given by new technologies, methods for digitization of the human body are used also in other fields of application, such as ergonomics, medical applications, computer games, biometry and anthropometrics. With the time, this technology becomes interesting also for sport, fitness, fashion and beauty. A large expansion of human body digitization is expected in the near future. To date, different technologies are used commercially for the measurement of the human body. They can be divided into three distinguished groups: laser-scanning, projection of light patterns, combination modeling and image processing. The different solutions have strengths and weaknesses that profile their suitability for specific applications. This paper gives an overview of their differences and characteristics and expresses clues for the selection of the adequate method. Practical examples of commercial exploitation of human body digitization are also presented and new interesting perspectives are introduced.

  2. Origins, bottlenecks, and present-day diversity: patterns of morphospace occupation in marine bivalves.

    PubMed

    Huang, Shan; Roy, Kaustuv; Jablonski, David

    2015-03-01

    It has long been known that species should not be distributed randomly in morphospace (a multidimensional trait space), even under simple models of evolution. However, recent studies suggest that position in morphospace can affect aspects of evolution such as the durations of clades and the species richness of their constituent taxa. Here we investigate the dynamics of morphospace occupancy in living and fossil marine bivalves using shell size and aspect ratio, two functionally important traits. Multiple lines of evidence indicate that the center of a family's morphospace today represents a location where taxonomic diversity is maximized, apparently owing to lower extinction rates. Within individual bivalve families, species with narrow geographic ranges are distributed throughout the morphospace but widespread species, which are generally expected to be extinction resistant, tend to be concentrated near the center. The morphospace centers of most species-rich families today (defined as the median value for all species in the family) tend to be close to the positions of the family founders, further suggesting an association between position in morphospace and net diversification rates. However, trajectories of individual subclades (genera) are inconsistent with the center of morphospace being an evolutionary attractor.

  3. Can Satellite Geodesy Disentangle Holocene Rebound and Present-Day Glacier Balance Signatures?

    NASA Technical Reports Server (NTRS)

    Irvins, E.; James, T.; Yoder, C.

    1995-01-01

    The secular drift of the precession of the ascending node of the LAGOES -1 satellite is apparently linked to the Earth s paleoclimate through the slow viscous response of the mantle to ice sheet/ocean mass transfer during the last great continental deglaciation . The secular node acceleration is particularly sensitive to the longest wavelengths of the paleo -surface loading that have been memorized by the mantle glacio -isostatic flow. Tide gauge records for the last 130 years show a post-glacial rebound-corrected sea-level rise of 2.4 n 0.9 mm yr-1.

  4. [Present-day hygienic aspects of dealing with industrial and consumption waste].

    PubMed

    Gil'denskiol'd, R S; Kur'ianova, I S

    2005-01-01

    The article covers scientific hygienic positions in forming and solving the acute scientific and technical problem of dealing with waste. The given problem is topical due to growing amount and diversity of waste and relatively small knowledge of ecological, medical and biological aspects of the problem. The paper covers the entire "life cycle" of waste, chiefly industrial and communal, as the most diverse and potentially dangerous to the environment. Special attention is paid to neutralization and recycling of waste for its application as secondary material in various branches of national economy. Having critically analized the results of complex studies, the authors conclude the article with outlining the prospective tasks of research for scientific and practical institutions of sanitary surveillance of Russian Federation Ministry of Health. PMID:15852717

  5. Present-day formation and seasonal evolution of linear dune gullies on Mars

    NASA Astrophysics Data System (ADS)

    Pasquon, Kelly; Gargani, Julien; Massé, Marion; Conway, Susan

    2016-04-01

    Linear dune gullies are an enigmatic sub-type of martian gullies. As their name suggests they only occur on sandy substrates and comprise very long (compared to their width) straight or sinuous channels, with relatively small source areas and almost inexistent deposits. This specific morphology has never been observed on terrestrial dunes and its formation process on Mars is still unclear [e.g. 1, 2, 3]. Here, we present the results of the first systematic survey for these features in Mars' southern hemisphere and an in-depth study of six dune fields where repeat-imaging allows us to monitor the changes over time of these linear gullies. This study was performed with HiRISE images at 25-30 cm/pix and 1 m/pix elevation data derived from HiRISE stereo images. We find the latitudinal distribution and orientation of linear gullies is broadly consistent with the general population of martian gullies. They occur predominantly between 36.3°S and 54.3°S, and occasionally between 64.6°S and 70.4°S. They are oriented towards SSW (between 150°N and 260°N). In contrast with the general gully population, however, we find that these gullies are extremely active over the 5 Mars years of images. Activity comprises: (i) appearance of new channels, (ii) elongation of existing channels, (iii) complete or partial reactivation, and (iv) disappearance of gullies. Gully channels can elongate by an average ~100 m per year. Their intense activity and the progressive disappearance of linear gullies argues against the hypothesis that these are remnant morphologies left over from previous periods of high obliquity millions of years ago. The activity of linear dune gullies reoccurs every year between the end of winter and the beginning of spring (Ls 167.4° - 216.6°), coinciding with the final stages of the sublimation of annual CO₂ frosts. This activity often coincides spatially and temporally with the appearance of Recurrent Diffusing Flows (RDF) - dark patches which surround the active site. South and SSW-facing dune slopes are those which preferentially host CO2 frost deposits, however, only those dune slopes with angles ~13° possess linear dune gullies, suggesting a slope-limited formation process. These observations provide a wealth of temporal and morphometric constraints that can be used to perform numerical modelling, to direct future image monitoring and guiding laboratory experiments which can be used to better constrain the formation process of these enigmatic features. [1] Mangold et al., 2003. J. Geophys. Res., 108 (E4), 5027. [2] Reiss et al., 2010. Geophys. Res. Lett. 37, L06203. [3] Diniega et al., 2013. Icarus 225, 526-537.

  6. Competing bounds on the present-day time variation of fundamental constants

    SciTech Connect

    Dent, Thomas; Stern, Steffen; Wetterich, Christof

    2009-04-15

    We compare the sensitivity of a recent bound on time variation of the fine structure constant from optical clocks with bounds on time-varying fundamental constants from atomic clocks sensitive to the electron-to-proton mass ratio, from radioactive decay rates in meteorites, and from the Oklo natural reactor. Tests of the weak equivalence principle also lead to comparable bounds on present variations of constants. The 'winner in sensitivity' depends on what relations exist between the variations of different couplings in the standard model of particle physics, which may arise from the unification of gauge interactions. Weak equivalence principle tests are currently the most sensitive within unified scenarios. A detection of time variation in atomic clocks would favor dynamical dark energy and put strong constraints on the dynamics of a cosmological scalar field.

  7. Inception of cadaver dissection and its relevance in present day scenario of medical education.

    PubMed

    Rath, Gayatri; Garg, Krishna

    2006-06-01

    The concept of dissection for acquiring knowledge about the structure of human body was started in 15th century and barber--surgeons used to demonstrate various structures at the professors command. Andreas Vesalius (1514-1564) was the first medical student to dissect the cadaver and also continued with it even as a professor. Slowly and steadily its importance was realised. Once autopsy was accepted as a ideal parameter to establish the causes of death, the importance of dissection got enhanced. Cadavers were obtained earlier from the grave robbings and mortuaries, which was followed by, an Anatomy Act of 1832, by which unclaimed bodies were provided to the anatomy department. For last two decades, many persons started donating their bodies to the department of anatomy. In India, mostly unclaimed bodies are handed over to anatomy department for teaching and research purpose. Cadavers teach students during 1st professional course, autopsy teaches again in IInd and IIIrd professional courses and even later on throughout the career. Dissection helps in developing a spatial and tactile appreciation for the fabric of the human body that cannot be achieved by prosection or computerised learning aids alone. PMID:17058553

  8. The Aberdeen Medico-Chirurgical Society 1789 to the present day: some leaders in medicine.

    PubMed

    Galloway, David B

    2011-02-01

    The Aberdeen Medico-Chirurgical Society was founded in 1789 based on a model of the Royal Medical Society of Edinburgh by Sir James McGrigor and 11 medical students. The objectives at that time, as at present, were to promote teaching, self education, the application of medical skills learned at the bedside, fellowship, and social intercourse. A number of examples of key leaders in the profession and members of the Medico-Chirurgical Society of Aberdeen are featured. These include Alexander Gordon (puerperal fever), Sir James McGrigor (founder of the British Army Medical Services), Sir Alexander Ogston (associated with Lister's theory of antisepsis in surgery and the discovery of the staphylococcus), Sir Patrick Manson (the father of tropical medicine), Prof JJR Macleod (Nobel Laureate and the discoverer of insulin), Prof Sir Matthew Hay (public health physician who offered the first description of typhus and its origins), and Sir Dugald Baird (the founder in the United Kingdom and Europe of modern-day maternity services).

  9. Scandinavian postglacial faults and their physical connection to present day seismicity

    NASA Astrophysics Data System (ADS)

    Arvidsson, R.

    2015-12-01

    In Scandinavia large earthquakes up to M~8.2 occurred 9500 yBP due to rapid deglaciation leaving fault scarps with lengths up to 160km and vertical offsets of at least 10 m. Today a lion share of local earthquakes are located to the vicinity of the faults. I show here from Coulomb failure stress modeling a physical connection between clustering of recent earthquakes and high Coulomb failure stresses around the faults. This can be interpreted In such a fashion that the location of the current earthquakes resembles locations of aftershock sequences. The explanation is that when these faults where formed it was due to state of stress in the crust at time of deglaciation, different from today's conditions. The crust was heavily depressed at deglaciation about 250 m in the region and due of the receding icesheet the crust was subjected to high stresses resulting in fault motion. This fault motion occurred in order to minimize state of stress at deglaciation. However, this state of stress has since changed with the regional postglacial uplift and thus today these faults remain as perturbations in the crust with concentrations of high stresses. I elaborate on this mechanism. I also advocate that this correlation between high stressed fault areas and locations of earthquakes indicates that seismicity within stable continental regions like Scandinavia might be caused by previous crustal disturbances that show local perturbations of the stress field. Therefore if faults are favorably oriented in the present stress field they can be released by brittle earthquake faulting . Thus past transient tectonic events can explain part of the stable continental region's seismicity. This may be of large importance to assessment of seismic hazard within stable continental regions particularly for critical structures like e.g., nuclear waste deposits and hydroelectric dams.

  10. [Present-day approach to pharmacological and clinical aspects of novel antidepressants].

    PubMed

    Danileviciūte, Vita; Sveikata, Audrius

    2002-01-01

    Depression is the most common illness that affects a large number of individuals in all countries. Recent evidence suggest that depressive episodes if left untreated may heighten severity of subsequent episodes and may increase need for more health care resources. The first antidepressants, tricyclics and monoamine oxidase inhibitors, became available in the late 1950s. A progressive tightening of requirements by drug licensing authorities has ensured that efficacy evidence is good for most antidepressants that are in use. Contemporary antidepressant classification system is based on the mechanism of action, which is presumed to be responsible for their antidepressant effects. A pharmacodynamic system of classification has advantages because it incorporates the current theories of disease pathophysiology. Understanding the basic aspects of mechanism of action of antidepressants is important for treatment of depressive episode, for development of augmenting strategies and combining antidepressants with other antidepressants or antipsychotics. Antidepressants as a class of psychotropic medication have the broad range of indications. The choice of initial antidepressant legitimately varies considerably among clinicians and countries. Referring to some differences of recommendations for the first line treatment of depressive episode we suppose that the choice of antidepressant medication must be individualized for a particular patient. Novel antidepressants (SSRI, SNRI, NaSSA, NARI, NDRI and other) are safe and better tolerated. Metabolism of novel antidepressants is much improved compared with MAOIs and TCAs. The combination of antidepressants is an important clinical issue. There are the following principles of combining antidepressants: 1. to combine mechanisms of action not just drugs, 2. to combine antidepressants and to promote pharmacological synergy and tolerability, 3. to use important synergies within the serotonin, noradrenaline and even dopamine monoaminergic systems. Adequate treatment of depression including modern treatment approaches has the potential to reduce suffering and disability substantially and minimise the risk of suicide. PMID:12552154

  11. Present-day groundwater recharge estimation in parts of the Indian Sub-Continent

    NASA Astrophysics Data System (ADS)

    Bhanja, S. N.; Mukherjee, A.; Wada, Y.; Scanlon, B. R.; Taylor, R. G.; Rodell, M.; Malakar, P.

    2015-12-01

    Large part of global population has been dependent on groundwater as a source of fresh water. The demand would further increase with increasing population and stress associated with climate change. We tried to provide regional-scale groundwater recharge estimates in a large part of Indian Sub-Continent. A combination of ground-based, satellite-based and numerical model simulated recharge estimates were presented in the densely populated region. Three different methods: an intense network of observational wells (n>13,000 wells), a satellite (TRMM) and global land-surface model (CLM) outputs, and a global-scale hydrological model (PCR GLOBWB) were employed to calculate recharge estimates. Groundwater recharge values exhibit large spatial variations over the entire region on the basis of aquifer hydrogeology, precipitation and groundwater withdrawal patterns. Groundwater recharge estimates from all three estimation techniques were found to be higher (>300 mm/year) in fertile planes of Indus-Ganges-Brahmaputra (IGB) river basins. A combination of favorable hydrogeologic conditions (porosity, permeability etc.), comparatively higher rates of precipitation, and return flow from rapidly withdrawn irrigation water might influence occurrence of high recharge rates. However, central and southern study area experiences lower recharge rates (<200 mm/year), might be associated with unfavorable hydrogeologic conditions associated with cratonic provinces. Statistical analysis of inter-comparison between the three different recharge estimates show good matches in some of the areas. Recharge estimates indicate dynamic nature of groundwater recharge as a function of precipitation, land use pattern, and hydrogeologic parameters. On a first hand basis, the estimates will help policy makers to understand groundwater recharge process over the densely populated region and finally would facilitate to implement sustainable policy for securing water security.

  12. Present-day Circum-Antarctic Simulations using the POPSICLES Coupled Ice Sheet-Ocean Model

    NASA Astrophysics Data System (ADS)

    Asay-Davis, X.; Martin, D. F.; Price, S. F.; Maltrud, M. E.; Collins, W.

    2014-12-01

    We present POPSICLES simulation results covering the full Antarctic Ice Sheet and the Southern Ocean spanning the period 1990 to 2010. Simulations are performed at 0.1o (~5 km) ocean resolution and with adaptive ice-sheet model resolution as fine as 500 m. We compare time-averaged melt rates below a number of major ice shelves with those reported by Rignot et al. (2013) as well as other recent studies. We also present seasonal variability and decadal trends in submarine melting from several Antarctic regions. Finally, we explore the influence on basal melting and system dynamics resulting from two different choices of climate forcing: a "normal-year" climatology and the CORE v. 2 forcing data (Large and Yeager 2008).POPSICLES couples the POP2x ocean model, a modified version of the Parallel Ocean Program (Smith and Gent, 2002), and the BISICLES ice-sheet model (Cornford et al., 2012). POP2x includes sub-ice-shelf circulation using partial top cells (Losch, 2008) and boundary layer physics following Holland and Jenkins (1999), Jenkins (2001), and Jenkins et al. (2010). Standalone POP2x output compares well with standard ice-ocean test cases (e.g., ISOMIP; Losch, 2008) and other continental-scale simulations and melt-rate observations (Kimura et al., 2013; Rignot et al., 2013). BISICLES makes use of adaptive mesh refinement and a 1st-order accurate momentum balance similar to the L1L2 model of Schoof and Hindmarsh (2009) to accurately model regions of dynamic complexity, such as ice streams, outlet glaciers, and grounding lines. Results of BISICLES simulations have compared favorably to comparable simulations with a Stokes momentum balance in both idealized tests (MISMIP-3D; Pattyn et al., 2013) and realistic configurations (Favier et al. 2014).A companion presentation, "Response of the Antarctic Ice Sheet to ocean forcing using the POPSICLES coupled ice sheet-ocean model" in session C024 covers the ice-sheet response to these melt rates in the coupled simulation. The figure shows eddy activity in the vertically integrated (barotropic) velocity nearly six years into a POPSICLES simulation of the Antarctic region.

  13. Water Isotopes in Precipitation: Data/Model Comparison for Present-Day and Past Climates

    NASA Technical Reports Server (NTRS)

    Jouzel, J.; Hoffmann, G.; Masson, V.

    1998-01-01

    Variations of HDO and H2O-18 concentrations are observed in precipitation both on a geographical and on a temporal basis. These variations, resulting from successive isotopic fractionation processes at each phase change of water during its atmospheric cycle, are well documented through the IAEA/WMO network and other sources. Isotope concentrations are, in middle and high latitudes, linearly related to the annual mean temperature at the precipitation site. Paleoclimatologists have used this relationship to infer paleotemperatures from isotope paleodata extractable from ice cores, deep groundwater and other such sources. For this application to be valid, however, the spatial relationship must also hold in time at a given location as the location undergoes a series of climatic changes. Progress in water isotope modeling aimed at examining and evaluating this assumption has been recently reviewed with a focus on polar regions and, more specifically, on Greenland. This article was largely based on the results obtained using the isotopic version of the NASA/GISS Atmospheric General Circulation Model (AGCM) fitted with isotope tracer diagnostics. We extend this review in comparing the results of two different isotopic AGCMs (NASA/GISS and ECHAM) and in examining, with a more global perspective, the validity of the above assumption, i.e. the equivalence of the spatial and temporal isotope-temperature relationship. We also examine recent progress made in modeling the relationship between the conditions prevailing in moisture source regions for precipitation and the deuterium-excess of that precipitation.

  14. Specific allogeneic unresponsiveness in the adult host: present-day experimental models

    SciTech Connect

    Rapaport, F.T.; Bachvaroff, R.J.; Cronkite, E.; Chanana, A.; Sato, T.; Asari, H.; Waltzer, W.C.

    1982-01-01

    As part of a long-term intensive effort to apply the induction of adult allogensic unresponsiveness to the transplantation problem, two techniques to control the variability in the persistence of immunologically competent postthymic cells iin the treated host and/or the inoculum of autologous marrow returned to the host after irradiation are described. The first consisted of exposing the peripheral blood of prospective recipients to a 5-week course of extra-corporeal irradiation (ECIB), the other of exposing the stored autologous marrow scheduled to repopulate a given recipient to methyl-prednisolone (MPd) and DNase prior to renifusion into the recipient. Serial analysis of bone marrow cell samples at various intervals before and after treatment was undertaken. The significance of the disappearance of a particular population of nonnuclear cells from the samples, and the association of such disappearance with increased success in the induction of allogeneic unresponsiveness is discussed. (ACR)

  15. Charting the Y-chromosome ancestry of present-day Argentinean Mennonites.

    PubMed

    Toscanini, Ulises; Brisighelli, Francesca; Llull, Cintia; Berardi, Gabriela; Gómez, Andrea; Andreatta, Fernando; Pardo-Seco, Jacobo; Gómez-Carballa, Alberto; Martinón-Torres, Federico; Álvarez-Iglesias, Vanesa; Salas, Antonio

    2016-06-01

    Old Order Mennonite communities initially arose in Northern Europe (centered in the Netherlands) and derived from the Anabaptist movement of the 16th century. Mennonites migrated to the New World in the early 18th century, first to North America, and more recently to Mesoamerica and South America. We analyzed Y-chromosome short tandem repeats (STRs) and single nucleotide polymorphisms in males from a community of Mennonites, 'La Nueva Esperanza', which arrived to Argentina in 1985 from colonies in Bolivia and Mexico. Molecular diversity indices coupled with demographic simulations show that Mennonites have a reduced variability when compared with local Argentinean populations and 69 European population samples. Mennonite Y-STR haplotypes were mainly observed in Central Europe. In agreement, multidimensional scaling analyses based on RST genetic distances indicate that Mennonite Y-chromosomes are closely related to Central/Northern Europeans (the Netherlands, Switzerland and Denmark). In addition, statistical inferences made on the most likely geographic origin of Y-chromosome haplotypes point more specifically to the Netherlands as the populations that best represent the majority of the Mennonite Y-chromosomes. Overall, Y-chromosome variation of Mennonites shows the signatures of moderate reduction of variability when compared with source populations, which is in good agreement with their lifestyle in small endogamous demes. These genetic singularities could also help to understand disease conditions that are more prevalent among Mennonites.

  16. Present Day Biology seen in the Looking Glass of Physics of Complexity

    NASA Astrophysics Data System (ADS)

    Schuster, P.

    Darwin's theory of variation and selection in its simplest form is directly applicable to RNA evolution in vitro as well as to virus evolution, and it allows for quantitative predictions. Understanding evolution at the molecular level is ultimately related to the central paradigm of structural biology: sequence⇒ structure ⇒ function. We elaborate on the state of the art in modeling and understanding evolution of RNA driven by reproduction and mutation. The focus will be laid on the landscape concept—originally introduced by Sewall Wright—and its application to problems in biology. The relation between genotypes and phenotypes is the result of two consecutive mappings from a space of genotypes called sequence space onto a space of phenotypes or structures, and fitness is the result of a mapping from phenotype space into non-negative real numbers. Realistic landscapes as derived from folding of RNA sequences into structures are characterized by two properties: (i) they are rugged in the sense that sequences lying nearby in sequence space may have very different fitness values and (ii) they are characterized by an appreciable degree of neutrality implying that a certain fraction of genotypes and/or phenotypes cannot be distinguished in the selection process. Evolutionary dynamics on realistic landscapes will be studied as a function of the mutation rate, and the role of neutrality in the selection process will be discussed.

  17. Subduction zones: Not relevant to present-day problems of waste disposal

    USGS Publications Warehouse

    Silver, E.A.

    1972-01-01

    SUBDUCTION zones are considered to be sites of disposal for vast areas of the Earth's surface1, while new surface is generated simultaneously at rise crests2. Bostrom and Sherif3 suggest that the world's industrial and domestic waste be dumped into subduction zones at deep sea trenches to allow nature to complete the recycling process at geologically rapid rates of 5 to 10 cm/yr. They also point out that trenches are often sites of rapid rates of deposition and suggest that the dumped wastes would, speaking geologically, soon be buried. Francis4 suggests that canisters of toxic chemical and radioactive wastes could be dumped onto trench sediments and be expected to sink at rates of 20 m/yr, assuming that the mass of turbidites in the trench fill often spontaneously liquefies on shaking by earthquakes. The assumption is based on the supposed lack of evidence for deformed sediment in trenches. I will argue that the suggestion of Bostrom and Sherif3 is not useful for the next few dozen generations of human populations and will point out observational evidence to show that Francis's4 assumption is incorrectly founded. ?? 1972 Nature Publishing Group.

  18. [From Leonardo Da Vinci to present days; from the history of antiplague costume].

    PubMed

    Kalmykov, A A; Aminev, R M; Korneev, A G; Polyakov, V S; Artebyakin, S V

    2016-01-01

    As a prototype of the antiplague costume can be considered a special clothing, which physicians in medieval Europe wear for protection in plague nidus. Inventor of the first antiplague costume is considered to be a French doctor Charles de Lorme (1619). Much later, in 1878, a Russian professor Pashutin V V offered to use a costume, which looked like a hermetically sealed "bag" with a special breathing device aimed at protection of medical staff. Later, professor O.I. Dogel's respirator became well-known (1889). At the beginning of 20th century as part of the antiplague costume was used a charcoal filter mask, invented by Zelinsky N.D. Requirements to order the use of modern means of individual protection when working in nidus of especially dangerous infections identified sanitary-epidemiological rules, which reflect issues of laboratory workers working and protective clothing, respiratory protection, and view, especially operation, the procedure of putting on, removing and disinfecting antiplague costumes, pneumocostumes, pneumohelmets, isolation suits, gas-protection boxes, etc.

  19. Simulation of present-day precipitation over India using a regional climate model

    NASA Astrophysics Data System (ADS)

    Maurya, Rajesh Kumar Singh; Singh, G. P.

    2016-04-01

    The objective of the present paper is to examine the capability of the regional climate model version 3 (RegCM3) to simulate the annual as well as seasonal precipitation variability over the Indian subcontinent. RegCM3 has been run at 40 km horizontal resolution for the period of 1982-2006 continuously and model results were compared to the observed precipitation datasets of India Meteorological Department (IMD) and CPC Merged Analysis of Precipitation (CMAP). Model evaluation has been done using different statistical methods like mean bias error (MBE), root mean square error, mean percentage error (MPE) and studied the spatial pattern of annual and seasonal variability and trend. Daily precipitation data at 1° × 1° grids of IMD have been used to study observed climatological means (both annual and seasonal), regression trends, interannual and intraseasonal variability over India from 1951 to 2007. The spatial distribution of annual precipitation shows a decreasing trend over west coast of India, central India, hilly region of India and an increasing trend is found over the northwest India, peninsular India and northeast India. The temporal distribution of daily precipitation shows highest rainfall of 18 mm/day in mid July (in composite flood cases only) and 12 mm/day during August (in composite drought cases only). The RegCM3 simulated annual and seasonal precipitation variability is close to the observed IMD and CMAP over all India (AI). During winter and pre-monsoon season, the model has overestimated the mean precipitation while underestimated in summer and post-monsoon season. Overall, annual precipitation showed the deficiency of -22.44 % compared to IMD and -1.41 % compared to CMAP over India. To understand the possible cause of annual and seasonal precipitation biases over India and its six homogeneous regions, the vertical difference (model mines National Centre for Environmental Prediction; NCEP) fields of water vapor mixing ratio (WVMR) and air temperature from surface to top level (1 σ-18 σ level) have been studied in detail. The model produced more moisture at the lower level during winter (JF) and pre-monsoon (MAM) season and reduced WVMR at the same levels during summer (JJAS) and post (OND) monsoon over India. High moisture content at the lower level simulated in the model can explain the increased precipitation during JF and MAM season and vice versa during JJAS and OND. Similar results were found over the homogeneous regions of India. This analysis indicates that the RegCM3 has more transport of vertical WVMR from surface to mid layer of the troposphere compared to NCEP.

  20. Present-day deformation across the Basin and Range Province, western United States

    USGS Publications Warehouse

    Thatcher, W.; Foulger, G.R.; Julian, B.R.; Svarc, J.; Quilty, E.; Bawden, G.W.

    1999-01-01

    The distribution of deformation within the Basin and Range province was determined from 1992, 1996, and 1998 surveys of a dense, 800-kilometer- aperture, Global Positioning System network, Internal deformation generally follows the pattern of Holocene fault distribution and is concentrated near the western extremity of the province, with lesser amounts focused near the eastern boundary. Little net deformation occurs across the central 500 kilometers of the network in western Utah and eastern Nevada. Concentration of deformation adjacent to the rigid Sierra Nevada block indicates that external plate-driving forces play an important role in driving deformation, modulating the extensional stress field generated by internal buoyancy forces that are due to lateral density gradients and topography near the province boundaries.

  1. Present-Day Deformation in Northeastern California, Northwest Nevada and Southern Oregon

    NASA Astrophysics Data System (ADS)

    Thatcher, W. R.; Svarc, J. L.; Lisowski, M.

    2014-12-01

    We use a newly expanded Global Positioning System (GPS) network in NE California, NW Nevada, and southern Oregon to estimate block rotation rates, slip rates on faults and internal block strain rates. The horizontal velocity field comprises 105 USGS campaign GPS sites surveyed during 1999-2014 and have velocity uncertainties less than 1 mm/yr, augmented by 21 continuous Plate Boundary Observatory sites operated since 2005. Sites near Mt. Shasta and Lassen volcanoes are excluded from the analysis to eliminate possible episodic magmatic deformation but stations near Medicine Lake Caldera are corrected for the known source of steady-state subsidence and local contraction. Most of the observed velocity field can be explained by counter-clockwise block rotation of ~0.3 deg/Ma about a pole located in northern Idaho and internal strain rates of < 20 ns/a. Slip rates on the known major extension faults (Surprise Valley, Klamath Graben, Goose Lake, and Hat Creek) are low, less than ~ 1 mm/yr. An earlier estimate of ~ 3 mm/yr of horizontal extension across the Hat Creek fault (Thatcher and Svarc, 2010 AGU) is not supported by the more accurate and spatially dense velocity field examined here.

  2. The chlorine budget of the present-day atmosphere - A modeling study

    NASA Technical Reports Server (NTRS)

    Weisenstein, Debra K.; Ko, Malcolm K. W.; Sze, Nien-Dak

    1992-01-01

    The contribution of source gases to the total amount of inorganic chlorine (ClY) is examined analytically with a time-dependent model employing 11 source gases. The source-gas emission data are described, and the modeling methodology is set forth with attention given to the data interpretation. The abundances and distributions are obtained for all 11 source gases with corresponding ClY production rates and mixing ratios. It is shown that the ClY production rate and the ClY mixing ratio for each source gas are spatially dependent, and the change in the relative contributions from 1950 to 1990 is given. Ozone changes in the past decade are characterized by losses in the polar and midlatitude lower stratosphere. The values for CFC-11, CCl4, and CH3CCl3 suggest that they are more evident in the lower stratosphere than is suggested by steady-state estimates based on surface concentrations.

  3. [Impact of motor activity on the musculoskeletal system of present-day schoolchildren].

    PubMed

    Mirskaia, N B; Kolomenskaia, A N; Siniakina, A D

    2010-01-01

    Moscow schoolchildren having prepathological and pathological states of the musculoskeletal system (MSS) have been found to have risk factors leading to these disorders, such as no optimal motor activity, incorrectly chosen and purposefully unused clothes and footwear, and a text-book wearing manner that is injurious to the MSS. Most parents of schoolchildren are unaware of their children's having prepathological and pathological states of the MSS, the modes of their prevention, correction, and treatment; however, they are ready to obtain knowledge on this problem.

  4. From Abbott Thayer to the present day: what have we learned about the function of countershading?

    PubMed Central

    Rowland, Hannah M.

    2008-01-01

    Of the many visual characteristics of animals, countershading (darker pigmentation on those surfaces exposed to the most lighting) is one of the most common, and paradoxically one of the least well understood. Countershading has been hypothesized to reduce the detectability of prey to visually hunting predators, and while the function of a countershaded colour pattern was proposed over 100 years ago, the field has progressed slowly; convincing evidence for the protective effects of countershading has only recently emerged. Several mechanisms have been invoked for the concealing function of countershading and are discussed in this review, but the actual mechanisms by which countershading functions to reduce attacks by predators lack firm empirical testing. While there is some subjective evidence that countershaded animals match the background on which they rest, no quantitative measure of background matching has been published for countershaded animals; I now present the first such results. Most studies also fail to consider plausible alternative explanations for the colour pattern, such as protection from UV or abrasion, and thermoregulation. This paper examines the evidence to support each of these possible explanations for countershading and discusses the need for future empirical work. PMID:19000972

  5. Discovery of Five Candidates for Present Day η Carinae Analogs in Nearby Galaxies

    NASA Astrophysics Data System (ADS)

    Khan, Rubab M.

    2016-01-01

    Late-stage evolution of the most massive stars such as η Carinae is controlled by the effects of mass loss, possibly dominated by poorly understood episodic mass ejections. Through a systematic search utilizing archival Spitzer and HST data, we have discovered five objects in the nearby (<10 Mpc) massive star-forming galaxies M51, M83, M101 and NGC6946 that have optical through mid-infrared photometric properties consistent with their being analogs of the hitherto unique η Car as it is presently observed. Prior to this discovery there were no known analogs of η Car either in our or other galaxies. These objects are very luminous, with Lbol=3-6×106 L⊙. Their Spitzer mid-infrared spectral energy distributions rise steeply in the 3.6-8 μm bands, then turn over between 8 and 24 μm indicating the presence of warm (~400-600 K) circumstellar dust. Their optical counterparts, identified in deep HST images, are 1.5-2 dex fainter relative to mid-IR peaks and require the presence of ~5-10 M⊙ obscuring material. We present the properties of these five sources and discuss the implications of our discovery for understanding massive star evolution.

  6. Sciences of the brain: The long road to scientific maturity and to present-day reductionism.

    PubMed

    Le Moal, Michel; Swendsen, Joël

    2015-01-01

    When examined in a long-term perspective, brain sciences demonstrate certain conceptual consistencies as well as theoretical oppositions that have lasted for centuries, ever since Ancient Greece. The neurosciences have progressed more on the basis of technological than conceptual advances, and the constant recuperation of new techniques from other sciences have led to a continually reductionist view of the brain and its functions. In a different perspective, if not opposite to the reductionism, are the psychological constructs and those that constitute the functional unity of individuals, which are still mysterious. In fact, the gap between these two approaches has never been larger than it is now. This chapter discusses the enduring nature of some of these problems and their recent consequences.

  7. Present-day crustal deformation in China constrained by global positioning system measurements.

    PubMed

    Wang, Q; Zhang, P Z; Freymueller, J T; Bilham, R; Larson, K M; Lai, X; You, X; Niu, Z; Wu, J; Li, Y; Liu, J; Yang, Z; Chen, Q

    2001-10-19

    Global Positioning System (GPS) measurements in China indicate that crustal shortening accommodates most of India's penetration into Eurasia. Deformation within the Tibetan Plateau and its margins, the Himalaya, the Altyn Tagh, and the Qilian Shan, absorbs more than 90% of the relative motion between the Indian and Eurasian plates. Internal shortening of the Tibetan plateau itself accounts for more than one-third of the total convergence. However, the Tibetan plateau south of the Kunlun and Ganzi-Mani faults is moving eastward relative to both India and Eurasia. This movement is accommodated through rotation of material around the eastern Syntaxis. The North China and South China blocks, east of the Tibetan Plateau, move coherently east-southeastward at rates of 2 to 8 millimeters per year and 6 to 11 millimeters per year, respectively, with respect to the stable Eurasia. PMID:11641493

  8. [Achievements of transfusiology during World War II 1941-1945 and its present-day problems].

    PubMed

    Ryzhkov, S V; Popov, S D

    1985-06-01

    The achievements of Soviet transfusiology in the period of the Great Patriotic War of 1941-1945 and of the Soviet medicine in the following years represent a basis for the successful development of Soviet transfusiology under modern conditions.

  9. Tectonic Escape and Present-Day Crustal Deformation in Northernmost Longitudinal Valley, Hualien Taiwan

    NASA Astrophysics Data System (ADS)

    Lee, J. C.; Chen, C. Y.; Chen, Y. G.; Chen, R. F.; Chen, H. Y.

    2014-12-01

    The Longitudinal Valley in Eastern Taiwan sits at the collision suture between the Eurasian and Philippine Sea plates. Based on repeated GPS campaigned measurements from 25 stations six times in 2007-2014 and 10 continuous GPS single-frequency stations recorded in 2011-2014, we characterize the surface deformation in the northernmost Longitudinal Valley where the Coastal Range of the Philippine Sea plate turns northward diving under the Eurasian plate producing two major active faults: the Milun fault and the Longitudinal Valley fault. We reconstructed a GPS velocity field and conducted strain analyses and elastic block modeling. Our results suggest a clockwise rotation at a rate of 33° M/yr and an eastward tectonic escape in the small Hualien City block (HUAL) area of ~10 × 10 km, which is apparently detached from the regional rotating RYUK block (~ 100 x 100 km) defined by previous studies. Combining the levelling data that indicated the Coastal Range is going down toward the north, we interpret the tectonic escape of the northernmost Longitudinal Valley as being initiated locally by the northwest indentation of the Coastal Range, which pushed the HUAL block to move upward and eastward. According to our strain analyses, the HUAL block shows a significant internal elastic strain inside the Milun Tableland, the hanging wall of the Milun fault. No significant deformation was observed across the surface trace of the fault, indicating that the Milun fault is now probably locked in the near surface. The deformation in the footwall of the fault was accommodated by pure-shear strain with a major NNW-compression and a minor ENE-extension. The deformation in the hanging wall is characterized by simple-shear strain with ENE-extension in its northern part and little deformation in the southern part, separated by a little known NW-trending active fault zone (Dongmingyi fault), which needs further investigation.

  10. Feasibility of laser pumping with neutron fluxes from present-day large tokamaks

    SciTech Connect

    Jassby, D.L.

    1986-08-01

    The minimum fusion-neutron flux needed to observe nuclear-pumped lasing with tokamaks can be reduced substantially by optimizing neutron scattering into the laser cell, located between adjacent toroidal-field coils. The laser lines most readily pumped are probably the /sup 3/He-Ne lines at 0.633 ..mu.. and in the infrared, where the /sup 3/He-Ne gas is excited by energetic ions produced in the /sup 3/He(n,p)T reaction. These lines are expected to lase at the levels of D-T neutron flux foreseen for the TFTR in 1989 (>>10/sup 12/ n/cm/sup 2//s), while amplification should be observable at the existing levels of D-D neutron flux (greater than or equal to 5 x 10/sup 9/ n/cm/sup 2//s). Lasing on the 1.73 ..mu.. and 2.63 ..mu.. transitions of Xe may be observable at the maximum expected levels of D-T neutron flux in TFTR enhanced by scattering.

  11. Present-day Block Motions and Strain Accumulation on Active Faults in the Caribbean

    NASA Astrophysics Data System (ADS)

    Symithe, S. J.; Calais, E.; Freed, A. M.

    2014-12-01

    The quasi-frontal subduction of the north and south American plates under the Lesser Antilles and the left and right lateral strike-slip along the northern and southern margins of the Caribbean plate offer the opportunity to study the transition from subduction to strike-slip between major plates. In addition, the segmentation and degree of interplate coupling at the Lesser Antilles subduction is key to our understanding of the earthquake potential of a subduction whose length is similar to the rupture area of the Mw9.0, 2011, Tohoku earthquake in Japan. We used the block modeling approach described in Meade and Loveless (2009) to test the optimal block geometry for the northern, eastern and southern boundaries of the Caribbean plate. We solved for angular velocities for each block/plate and strain accumulation rates for all major faults in the region. Then we calculated the variations in interplate coupling along the subduction plate boundaries using the accumulated strain rates. We tested 11 different block geometries; they are all based on geological evidences unless they are suggested by discrepancies within the GPS and seismological data or by previously published results. We confirm the existence of the micro Gonave plate. The boundary between the Micro-Gonave plate and the Hispaniola crustal block is better suited along the Haitian-Thrust-Belt instead of the Neiba-Matheux fault. The interseismic GPS velocities do not show evidence for a distinct North Lesser Antilles block. We found a totally uncoupled section of the subduction starting from the Puerto-Rico trench to the end of the Lesser Antilles section. All the relative motion of the Caribbean block is lost aseismically along the boundary of that portion of the subduction. While we found strong coupling along the northern Hispaniola section, most of the deformation on this region is being accumulated along intrablock faults with very low strain (~2mm/yr) along the intraplate subduction interface. We also performed several tests resolutions to assess the ability of the existing GPS data and the associated uncertainties to adequately resolved different aspects of the strain accumulation along the subduction. We found reasonable lateral resolution and very poor vertical resolution.

  12. Present-day shortening in Southern Haiti from GPS measurements and implications for seismic hazard

    NASA Astrophysics Data System (ADS)

    Symithe, Steeve; Calais, Eric

    2016-06-01

    The ~ 3 M inhabitant capital region of Haiti, severely affected by the devastating January 12, 2010, M7.0 earthquake, continues to expand at a fast rate. Accurate characterization of regional earthquake sources is key to inform urban development and construction practices through improved regional seismic hazard estimates. Here we use a recently updated Global Positioning System (GPS) data set to show that seismogenic strain accumulation in southern Haiti involves an overlooked component of shortening on a south-dipping reverse fault along the southern edge of the Cul-de-Sac basin, in addition to the well-known component of left-lateral strike-slip motion. This tectonic model implies that ground shaking may be twice that expected if the major fault was purely strike-slip, as assumed in the current seismic hazard map for the region.

  13. Two Words of Chinese Origin in Present-Day Peruvian Spanish

    ERIC Educational Resources Information Center

    Horton, James F.

    1977-01-01

    The origin, etymology and phonology of two words of Chinese origin found in Peruvian Spanish are outlined. The words, "chifa" and "chaufa," derive from Cantonese words for "rice" and have been adapted into Spanish. (CHK)

  14. Acceptance or refusal of convenience food in present-day prison.

    PubMed

    Vanhouche, An-Sofie

    2015-11-01

    Food in prison is an insufficiently researched topic. However, prisoners often highlight problems with and criticism of their prison meals. This article aims to further develop this topic by giving closer insight into the use and attitudes toward ready-made meals in the Tilburg prison. In this prison, prisoners receive ready-made meals. This is in contrast to Belgian prisons, from which they were transferred, where meals were made from scratch. This change in the food system led to commotion and complaints. To understand the situation, interviews with prisoners and staff were conducted and observations in the Tilburg prison were made. The results showed that a food system can have considerable influence on prison experiences. In addition, and contrary to what earlier reports have mentioned, the ready-made meals also have some advantages, especially for the organization of daily prison life. However, most prisoners had negative attitudes toward these meals. PMID:25891041

  15. Competing bounds on the present-day time variation of fundamental constants

    NASA Astrophysics Data System (ADS)

    Dent, Thomas; Stern, Steffen; Wetterich, Christof

    2009-04-01

    We compare the sensitivity of a recent bound on time variation of the fine structure constant from optical clocks with bounds on time-varying fundamental constants from atomic clocks sensitive to the electron-to-proton mass ratio, from radioactive decay rates in meteorites, and from the Oklo natural reactor. Tests of the weak equivalence principle also lead to comparable bounds on present variations of constants. The “winner in sensitivity” depends on what relations exist between the variations of different couplings in the standard model of particle physics, which may arise from the unification of gauge interactions. Weak equivalence principle tests are currently the most sensitive within unified scenarios. A detection of time variation in atomic clocks would favor dynamical dark energy and put strong constraints on the dynamics of a cosmological scalar field.

  16. Modelling of hybrid scenario: from present-day experiments towards ITER

    NASA Astrophysics Data System (ADS)

    Litaudon, X.; Voitsekhovitch, I.; Artaud, J. F.; Belo, P.; Bizarro, João P. S.; Casper, T.; Citrin, J.; Fable, E.; Ferreira, J.; Garcia, J.; Garzotti, L.; Giruzzi, G.; Hobirk, J.; Hogeweij, G. M. D.; Imbeaux, F.; Joffrin, E.; Koechl, F.; Liu, F.; Lönnroth, J.; Moreau, D.; Parail, V.; Schneider, M.; Snyder, P. B.; the ASDEX-Upgrade Team; Contributors, JET-EFDA; the EU-ITM ITER Scenario Modelling Group

    2013-07-01

    The ‘hybrid’ scenario is an attractive operating scenario for ITER since it combines long plasma duration with the reliability of the reference H-mode regime. We review the recent European modelling effort carried out within the Integrated Scenario Modelling group which aims at (i) understanding the underlying physics of the hybrid regime in ASDEX-Upgrade and JET and (ii) extrapolating them towards ITER. JET and ASDEX-Upgrade hybrid scenarios performed under different experimental conditions have been simulated in an interpretative and predictive way in order to address the current profile dynamics and its link with core confinement, the relative importance of magnetic shear, s, and E × B flow shear on the core turbulence, pedestal stability and H-L transition. The correlation of the improved confinement with an increased s/q at outer radii observed in JET and ASDEX-Upgrade discharges is consistent with the predictions based on the GLF23 model applied in the simulations of the ion and electron kinetic profiles. Projections to ITER hybrid scenarios have been carried out focusing on optimization of the heating/current drive schemes to reach and ultimately control the desired plasma equilibrium using ITER actuators. Firstly, access condition to the hybrid-like q-profiles during the current ramp-up phase has been investigated. Secondly, from the interpreted role of the s/q ratio, ITER hybrid scenario flat-top performance has been optimized through tailoring the q-profile shape and pedestal conditions. EPED predictions of pedestal pressure and width have been used as constraints in the interpretative modelling while the core heat transport is predicted by GLF23. Finally, model-based approach for real-time control of advanced tokamak scenarios has been applied to ITER hybrid regime for simultaneous magnetic and kinetic profile control.

  17. Present-day stress field in subduction zones: Insights from 3D viscoelastic models and data

    NASA Astrophysics Data System (ADS)

    Petricca, Patrizio; Carminati, Eugenio

    2016-01-01

    3D viscoelastic FE models were performed to investigate the impact of geometry and kinematics on the lithospheric stress in convergent margins. Generic geometries were designed in order to resemble natural subduction. Our model predictions mirror the results of previous 2D models concerning the effects of lithosphere-mantle relative flow on stress regimes, and allow a better understanding of the lateral variability of the stress field. In particular, in both upper and lower plates, stress axes orientations depend on the adopted geometry and axes rotations occur following the trench shape. Generally stress axes are oriented perpendicular or parallel to the trench, with the exception of the slab lateral tips where rotations occur. Overall compression results in the upper plate when convergence rate is faster than mantle flow rate, suggesting a major role for convergence. In the slab, along-strike tension occurs at intermediate and deeper depths (> 100 km) in case of mantle flow sustaining the sinking lithosphere and slab convex geometry facing mantle flow or in case of opposing mantle flow and slab concave geometry facing mantle flow. Along-strike compression is predicted in case of sustaining mantle flow and concave slabs or in case of opposing mantle flow and convex slabs. The slab stress field is thus controlled by the direction of impact of mantle flow onto the slab and by slab longitudinal curvature. Slab pull produces not only tension in the bending region of subducted plate but also compression where upper and lower plates are coupled. A qualitative comparison between results and data in selected subductions indicates good match for South America, Mariana and Tonga-Kermadec subductions. Discrepancies, as for Sumatra-Java, emerge due to missing geometric (e.g., occurrence of fault systems and local changes in the orientation of plate boundaries) and rheological (e.g., plasticity associated with slab bending, anisotropy) complexities in the models.

  18. Microbial Diversity Analysis of the Bacterial and Archaeal Population in Present Day Stromatolites

    NASA Technical Reports Server (NTRS)

    Ortega, Maya C.

    2011-01-01

    Stromatolites are layered sedimentary structures resulting from microbial mat communities that remove carbon dioxide from their environment and biomineralize it as calcium carbonate. Although prevalent in the fossil record, stromatolites are rare in the modem world and are only found in a few locations including Highbome Cay in the Bahamas. The stromatolites found at this shallow marine site are analogs to ancient microbial mat ecosystems abundant in the Precambrian period on ancient Earth. To understand how stromatolites form and develop, it is important to identify what microorganisms are present in these mats, and how these microbes contribute to geological structure. These results will provide insight into the molecular and geochemical processes of microbial communities that prevailed on ancient Earth. Since stromatolites are formed by lithifying microbial mats that are able to mineralize calcium carbonate, understanding the biological mechanisms involved may lead to the development of carbon sequestration technologies that will be applicable in human spaceflight, as well as improve our understanding of global climate and its sustainability. The objective of my project was to analyze the archaeal and bacterial dIversity in stromatolites from Highborn Cay in the Bahamas. The first step in studying the molecular processes that the microorganisms carry out is to ascertain the microbial complexity within the mats, which includes identifying and estimating the numbers of different microbes that comprise these mats.

  19. Present-day fluxes of coccolithophores and diatoms in the pelagic Ionian Sea

    NASA Astrophysics Data System (ADS)

    Malinverno, Elisa; Maffioli, Paola; Corselli, Cesare; De Lange, Gert J.

    2014-04-01

    Biogenic fluxes from two sediment traps in the Ionian sea (35°13‧N, 21°30‧E) at 500 and 2800 m water depth are discussed in relation with the main oceanographic and external forcing and compared with previous data from a nearby location. This study is part of a multi-year sediment trap deployment, aimed at assessing seasonality and interannual variability of biogenic and abiogenic fluxes. Here, we focus on fluxes related to two main phytoplankton groups: coccolithophores and diatoms. At our mooring site, high-coccolithophore and low-diatom fluxes confirm the oligotrophic character of the pelagic eastern Mediterranean year-round. Coccolithophore assemblages are dominated by the cosmopolitan species Emiliania huxleyi, followed by the deep-dwelling Florisphaera profunda and by several minor species. Diatom assemblages are dominated by Thalassionema bacillare and Nitzschia interruptestriata, with ~ 100 common and minor species. Overall, the combined flux pattern of coccolithophores and diatoms shows a clear seasonality throughout the study period, which can be related to changing oceanographic conditions and a different depth of production within the photic zone. Worth to note is the extremely high abundance, with respect to previous pelagic records, of species indicative of an intense deep chlorophyll maximum (DCM), which could indicate a shoaling of the nutricline. This feature can be related to the variability that affects surface hydrography and the deep water masses. Additionally, the occurrence of neritic, benthic and brackish to fresh-water diatom species, mainly in the deeper trap, could be linked to either lateral transport within the water column or the atmospheric input of Saharan dust, which is known to be common over the eastern Mediterranean especially during spring time. Finally, correlation of the flux pattern at different depths allowed sinking speeds for total and biogenic particles to be calculated, which ranged from 70 to > 200 m day- 1. Three possible mechanisms can explain such high sinking rates and the coincidence of biogenic and total particle fluxes in the traps: a) the ballast effect of coccoliths; b) the packaging effect of fecal pellets related to the grazing activity of zooplankton; and c) the ballast effect of dust particles.

  20. Effects of present-day deglaciation in Iceland on mantle melt production rates

    NASA Astrophysics Data System (ADS)

    Schmidt, P.; Lund, B.; Hieronymus, C.; Maclennan, J.; Árnadóttir, T.; Pagli, C.

    2013-07-01

    Ongoing deglaciation in Iceland not only causes uplift at the surface but also increases magma production at depth due to decompression of the mantle. Here we study glacially induced decompression melting using 3-D models of glacial isostatic adjustment in Iceland since 1890. We find that the mean glacially induced pressure rate of change in the mantle increases melt production rates by 100-135%, or an additional 0.21-0.23 km3 of magma per year beneath Iceland. Approximately 50% of this melt is produced underneath central Iceland. The greatest volumetric increase is found directly beneath Iceland's largest ice cap, Vatnajökull, colocated with the most productive volcanoes. Our models of the effect of deglaciation on mantle melting predict a significantly larger volumetric response than previous models which only considered the effect of deglaciation of Vatnajökull, and only mantle melting directly below Vatnajökull. Although the ongoing deglaciation significantly increases the melt production rate, the increase in melt supply rate at the base of the lithosphere is delayed and depends on the melt ascent velocity through the mantle. Assuming that 25% of the melt reaches the surface, the upper limit on our deglaciation-induced melt estimates for central Iceland would be equivalent to an eruption the size of the 2010 Eyjafjallajökull summit eruption every seventh year.

  1. Effects of present day deglaciation in Iceland on the mantle melt production rate

    NASA Astrophysics Data System (ADS)

    Schmidt, Peter; Lund, Björn; Hieronymus, Christoph; Maclennan, John; Árnadóttir, Thora; Pagli, Carolina

    2013-04-01

    The ongoing deglaciation in Iceland not only causes uplift at the surface but also decompression of the mantle below, leading to increased magma production. Here we study glacially induced decompressional melting using 3D models of glacial isostatic adjustment in Iceland since 1890. We find that the mean glacially induced pressure rate of change in the mantle increases the melt production rate by 100-140%, or an additional 0.21-0.23 km3 of magma per year across Iceland. The greatest volumetric increase is found directly beneath the largest ice cap Vatnajökull, co-located with the most productive Icelandic volcanoes, where approximately 20% of the melt associated with glacial unloading is generated. If, in addition, melts are being channeled from the flanks of the melting region towards the central rift, up to 50% of the additional magma might reach the base of the elastic lithosphere beneath or close to the Vatnajökull ice cap, equivalent to more than half of the magma volume extruded during the 2010 Eyjafjallajökull summit eruption per year. Our results are significantly larger than previous estimates which considered only the effect of deglaciation of Vatnajökull and mantle melting directly beneath. Although the ongoing deglaciation in Iceland significantly increases the melt production rate in the mantle, the increase in melt supply rate (MSR) at the base of the lithosphere is delayed. If the melt ascent velocity is lower than 1,000 m/yr, the additional MSR caused by the last 120 years of deglaciation will continue to increase.

  2. Acceptance or refusal of convenience food in present-day prison.

    PubMed

    Vanhouche, An-Sofie

    2015-11-01

    Food in prison is an insufficiently researched topic. However, prisoners often highlight problems with and criticism of their prison meals. This article aims to further develop this topic by giving closer insight into the use and attitudes toward ready-made meals in the Tilburg prison. In this prison, prisoners receive ready-made meals. This is in contrast to Belgian prisons, from which they were transferred, where meals were made from scratch. This change in the food system led to commotion and complaints. To understand the situation, interviews with prisoners and staff were conducted and observations in the Tilburg prison were made. The results showed that a food system can have considerable influence on prison experiences. In addition, and contrary to what earlier reports have mentioned, the ready-made meals also have some advantages, especially for the organization of daily prison life. However, most prisoners had negative attitudes toward these meals.

  3. [Schizoaffective disorder: clinical symptoms and present-day approach to treatment].

    PubMed

    Danileviciūte, Vita

    2002-01-01

    During 20th century serious mental disorders were divided into two groups according symptomatology and course of disorder. Individuals with dominating disturbance of perception, thinking and cognition were basically diagnosed having schizophrenic. Individuals with mood disturbance were basically diagnosed having affective disorders. However, there were patients who did not fit neatly into either category. In 1933 Jocob Kasanin introduced the term "schizoaffective psychosis". Scientific discussions involved the possibility that schizoaffective disorder was conceptualized most accurately as following: a type of schizophrenia, a type of affective disorder, a unique disorder that was separate from both schizophrenia and bipolar disorder, an arbitrary categorization of clinical symptoms that marked a continuum between schizophrenia and affective illness, a heterogeneous collection of "interforms" between schizophrenia and affective disorders. However, diagnosis of schizoaffective disorder is included both in DSM-IV-TR and ICD-10. Schizoaffective disorder is listed in the category "schizophrenia and other psychotic disorders". The differential diagnosis includes basically either schizophrenia or affective disorder. The epidemiological status of schizoaffective disorder is somewhat uncertain compared with schizophrenia because of dilemmas related to diagnosis and classification of the disorder. Treatment of schizoaffective disorder comprises psychotropic medication, supportive psychotherapy, social care, rehabilitation. The most important groups of psychotropic medications are: antipsychotics, antidepressants and mood stabilizers. Atypical antipsychotics are the first-line medication for schizoaffective disorder due to their pharmacological properties. In the case of schizoaffective disorders combination of atypical antipsychotics with antidepressants seems to be useful. Novel antidepressants have priority for the combination mentioned above. Peculiarities of mechanism of action of antidepressant are important for combinations. Mood stabilizers seem to be useful for treatment of certain type of schizoaffective disorder as well.

  4. A summary of present-day gully formation and activity on Mars

    NASA Astrophysics Data System (ADS)

    Diniega, Serina; Hansen, Candice; McEwen, Alfred; Dundas, Colin; Byrne, Shane

    2016-07-01

    Over the past decade, gully activity has been carefully monitored on a range of slopes, including dune slopes [1-3] and crater walls [2-4]. Within the southern mid-latitudes, substantial changes in gully morphology have been observed. On dune slopes, observed activity includes major incision (forming a new channel or expanding an existing channel), changes in channel sinuosity, expansion of alcoves, and deposition of an extensive new apron. On rockier slopes, observed activity has cut new channel segments and small terraces, abandoned other channels, and deposited boulder-rich lobate features. Many of these morphologies have been treated as indicative of fluvial processes. However, long-term monitoring campaigns with High Resolution Imaging Science Experiment (HiRISE) data [2-5] of almost 500 gully locations, have shown that the timing of this current activity is generally correlated with the presence of seasonal frost [1-5]. Moreover, the distribution of seasonal frost on slopes is similar to the orientation distribution of gullies [3,6]. Most seasonal frost is CO2, and this is likely the main cause of current activity. Recent modeling has shown that CO2 sublimation from within the regolith pores would be sufficient to create the types of geomorphology seen within martian gullies [7]. Water frost may be involved in some small-scale activity [5]. Liquid water is unlikely to be relevant, because the abundance of water frost is generally low [8] and melting is difficult. An additional current focus is on the north polar sand sea, where "gullies" (generally lacking a channel) have been observed to form on dune slopes over seasonal and annual timescales. There, we aim to differentiate between either a general aeolian [8] or seasonal frost driver [9,10] for the formation process. For these features, formation timing estimates are often less constrained because HiRISE images are not acquired during fall and winter, due to the polar hood and darkness. Thus, analysis of trends and variations in gully size, morphology, orientation, and location are additionally examined as indications of a seasonal (or other) control, as well as variations with latitude, dune type/size/orientation, or Mars year. This presentation will summarize the results of our monitoring campaigns, and will compare the data that are available about gullies of different morphologies and locations. Our aim is to identify possible similarities (and differences) in gully activity processes across Mars, and to estimate the rates of gully formation and modification processes (as has been done for gullies in the southern mid-latitudes [3]). Such estimates would aid interpretation of the likely ages of observed gullies, which have implications for whether records of past (and potential aqueous) gully formation processes are still observable. [1] Diniega et al. (2010) Geology, 38, 1047-1050. [2] Dundas et al. (2012) Icarus, 220, 124-143. [3] Dundas et al. (2015) Icarus, 251, 244-263. [4] Dundas et al. (2010) GRL, 37, L07202. [5] Vincendon (2015) JGR, 120, 1859-1879. [6] Harrison et al. (2015) Icarus, 252, 236-254. [7] Pilorget & Forget (2016) Nature Geosci. 9, 65-69. [8] Vincendon et al. (2010) JGR, 115, E10001. [9] Horgan & Bell (2012) Geophys. Res. Lett. 39, L09201. [10] Hansen et al., (2011) Science 331, 575-578. [11] Hansen et al. (2015) Icarus 251, 264-267.

  5. MCTP Summer Research Internship Program. Research Presentation Day: Experience Mathematics and Science in the Real World

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This paper presents the summaries of the MCTP Summer Research Internship Program. Technological areas discussed include: Mathematical curriculum development for real world problems; Rain effects on air-water gas exchange; multi-ring impact basins on mars; developing an interactive multimedia educational cd-rom on remote sensing; a pilot of an activity for for the globe program; fossils in maryland; developing children's programming for the american horticultural society at river farm; children's learning, educational programs of the national park service; a study of climate and student satisfaction in two summer programs for disadvantaged students interested in careers in mathematics and science; the maryland governor's academy, integrating technology into the classroom; stream sampling with the maryland biological stream survey (MBSS); the imaging system inspection software technology, the preparation and detection of nominal and faulted steel ingots; event-based science, the development of real-world science units; correlation between anxiety and past experiences; environmental education through summer nature camp; enhancing learning opportunities at the Salisbury zoo; plant growth experiment, a module for the middle school classroom; the effects of proxisome proliferators in Japanese medaka embryos; development of a chapter on birth control and contraceptive methodologies as part of an interactive computer-based education module on hiv and aids; excretion of gentamicin in toadfish and goldfish; the renaissance summer program; and Are field trips important to the regional math science center?

  6. Present-day crustal deformation in central Alborz (Iran) inferred from GPS measurements

    NASA Astrophysics Data System (ADS)

    Vernant, P.; Nilforoushan, F.; Bayer, R.; Sedighi, M.; Chery, J.; Tavakoli, F.; Masson, F.

    2003-04-01

    The Alborz range is an active mountain belt south of the Caspian sea. The main tectonic structures of Alborz are generally overthrusting range-parallel faults northward dipping in the south and southward dipping in the north. The regular occurrence of large historical earthquakes in this range suggests an important activity of the faults. To study the internal deformation (horizontal and vertical movements) of the Alborz range, we have installed a GPS network of 12 sites crossing the Alborz range 50 km east of Tehran. Three epochs of measurements have been recorded during the falls 2000, 2001 and 2002. A previous study using a network covering the whole country has suggested that the central Alborz is accommodating ~8 mm/yr of the ~21 mm/yr of the north-south convergence between Arabia and Eurasia. Our new data processed with GAMIT and GLOBK provide a velocity field consistent with the shortening rate in Alborz. The mean repeatability values obtained for the network baselines are about 1-1.5 mm for north and east Component for each surveys. The three epochs of measurements allow to closely define the errors associated to the sites, they are about 1.5-2 mm/yr. Most of the shortening seems to be accommodated by the southern and northern frontal parts of the range which may absorb ~4 and ~3 mm/yr respectively. Deformation in the central part remains poorly sampled due to a landslide affecting a point at about 200 mm/yr to the SE. However, the shortening of the inner part of the range appears to be modest (~1 mm/yr). Because left lateral displacements are known in central Alborz, we have tried to interpret our results in order to define the long term velocities of these faults. Assuming that most of the strike-slip motion occurs on the Mosha fault which is orientated N100°E, GPS results suggest an interseismic left lateral slip rate of about 4mm/yr between sites north and south of the fault. This is consistent with the geological slip rate proposed by Ritz et al. (this meeting) on the base of geomorphic analysis of the Mosha fault. Moreover, the displacements of the sites on each side of the fault suggest a locked fault during the two last years.

  7. Accuracy of vertical deflection determination by present-day inertial instrumentation

    NASA Technical Reports Server (NTRS)

    Schwarz, K. P.

    1978-01-01

    An analysis of results obtained in the Canadian Rock Mountains indicates that the observation of deflection differences along the same line can be repeated with a precision of about 0.5 sec but that there are systematic discrepancies between the forward and the backward running of the same line. A comparison with the available astronomically determined deflections also shows systematic differences of 2 sec and 3 sec. These errors are most likely due to the overshooting of the Kalman procedure at gradient changes. It appears that the software can be altered in such a way that deflection differences between stations, not more than half an hour of travel time apart, can be determined by the inertial system with an accuracy of better than + or - 1 sec.

  8. South-France caves monitoring : present day cave air dynamics characterization,paleoclimatic and archaeological interests

    NASA Astrophysics Data System (ADS)

    Bourges, F.; Genty, D.; Genthon, P.; Mangin, A.; D'Hulst, D.

    2012-04-01

    Cave climatic environment survey covers different sort of analyses on air and water, and has various interests from the conservation of prehistoric caves to the study of paleoclimates. Depending on the purpose, the cave monitoring can be entirely automatic or combine both automatic and manual data acquisitions. Apparatus are adapted to cave environment to measure specific parameters (i.e. drip rate, air humidity, CO2) and during the long-term monitorings, several generations of techniques have been used. We present here examples of cave monitoring (1996 →) from South-France: Chauvet, Orgnac (Ardèche), Esparros (Hautes-Pyrénées) and Villars (Dordogne). In all these sites, we obtained among the longest series of climatic parameters of inside the caves, coupled sometimes with geochemical and isotopic analyses on air and seepage water, which allow to better understand cave air circulation behaviour and their sensitivity to the external climatic and environmental variations. High precision temperature measurements in Orgnac and Chauvet caves, coupled with pCO2 and radon analyses, allowed the reconstruction of seasonal air circulation patterns in each cave. While the Chauvet and Esparros caves are quite confined environments with temperature changes mainly controlled by air pressure variations, the Orgnac cave, like most caves, shows a well marked summer/winter regime alternation. Quantification of air flows of known CO2 concentration allowed the calculation of carbon fluxes toward the earth atmosphere which is estimated to about 340 gm-2yr-1. Since 15 years, the monitoring made in the Villars cave at two different levels has shown that the air temperature displays small seasonal variations in the upper galleries while it is not detectable in the lower ones. Average annual temperature difference between these two levels is of more than 1°C, showing that local differences in a single cave can be significant. A global warming trend likely correlated with local external temperature changes is observed in both levels since the beginning of the monitoring in 1996 which is not the case in Chauvet and Esparros caves. The stable isotope composition of the seepage water of the Villars cave and drip rates measured under several stalactites give precious information about the mixture of the rainfall infiltration signal in the unsaturated zone; these long isotopic series are discussed and compared with the rainfall (quantity and isotopic composition) sampled at this site.

  9. Present-day plate motions: Retrieval from the TOPEX/Poseidon orbitography network (DORIS system)

    NASA Technical Reports Server (NTRS)

    Souriau, Annie; Cazenave, Anny; Biancale, R.; Balmino, G.; Dominh, K.; Mazzega, P.; Lemoine, J.-M.; Boucher, Claude; Willis, P.; Kasser, M.

    1991-01-01

    The goal of the proposal is to determine the present motion of the main tectonic plates from the Doppler data of the Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) orbitography system, which includes in its final configuration about 50 tracking stations with a world-wide distribution.

  10. The past and present day of kiwifruit (Actinidia deliciosa Planch.) breeding in Pazar watershed, Turkey.

    PubMed

    Yuksek, Turan; Yuksek, Filiz; Sutlu, Ercan

    2007-04-15

    In this study, the problems of kiwifruit breeding in Pazar watershed which is 37 km east of city of Rize were investigated with public survey and the results of public survey were presented in two periods (1996-2002, 2002-2006). According to the results of questionnarie of the year 2002; 57.7% of total kiwifruit producers started to establish kiwifruit garden to gain additional income and 62.02% of total kiwifruit gardens were established less then 1000 m2 area, 24.05% of total kiwifruit producers did not do any search about kiwifruit breeding, while 38.8% of total farmers met serious problems while planting and caring of kiwifruit seedling, harvesting and marketing werent serious problem. During the second period (2002-2006) the numbers of kiwifruit producers who wanted to additional income increased 5.26 percantage and in this period 66.66% of total kiwifruit gardens were established less then 1000 m2 area and they and 81.48% of total kiwi farmers obtained kiwifruit seedlings from public bazaar and 55.55% of total kiwifruit farmers did not to any kind of site preparation before they planting of kiwifruit seedlings. Agricultural activities are still being practiced because most people are socially and economically dependent on such activities in the area.

  11. Sedimentological processes and environmental variability at Lake Ohrid (Macedonia, Albania) between 640 ka and present day

    NASA Astrophysics Data System (ADS)

    Francke, A.; Wagner, B.; Just, J.; Leicher, N.; Gromig, R.; Baumgarten, H.; Vogel, H.; Lacey, J. H.; Sadori, L.; Wonik, T.; Leng, M. J.; Zanchetta, G.; Sulpizio, R.; Giaccio, B.

    2015-09-01

    Lake Ohrid (FYROM, Albania) is thought to be more than 1.2 million years old and hosts more than 200 endemic species. As a target of the International Continental Scientific Drilling Program (ICDP), a successful deep drilling campaign was carried out within the scope of the Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO) project in 2013. Here, we present lithological, sedimentological, and (bio-)geochemical data from the upper 247.8 m of the overall 569 m long DEEP site sediment succession from the central part of the lake. According to an age model, which is based on nine tephra layers (1st order tie points), and on tuning of biogeochemical proxy data to orbital parameters (2nd order tie points) and to the global benthic isotope stack LR04 (3rd order tie points), respectively, the analyzed sediment sequence covers the last 640 ka. The DEEP site sediment succession consists of hemipelagic sediments, which are interspersed by several tephra layers and infrequent, thin (< 5 cm) mass wasting deposits. The hemipelagic sediments can be classified into three different lithotypes. Lithotype 1 and 2 deposits comprise calcareous and slightly calcareous silty clay and are predominantly attributed to interglacial periods with high primary productivity in the lake during summer and reduced mixing during winter. The data suggest that high ion and nutrient concentrations in the lake water promoted calcite precipitation and diatom growth in the epilmnion in during MIS15, 13, and 5. Following a strong primary productivity, highest interglacial temperatures can be reported for MIS11 and 5, whereas MIS15, 13, 9, and 7 were comparable cooler. Lithotype 3 deposits consist of clastic, silty clayey material and predominantly represent glacial periods with low primary productivity during summer and longer and intensified mixing during winter. The data imply that most severe glacial conditions at Lake Ohrid persisted during MIS16, 12, 10, and 6 whereas somewhat warmer temperatures can be inferred for MIS14, 8, 4, and 3. Interglacial-like conditions occurred during parts of MIS14, and 8.

  12. How Are Preferences Revealed?

    PubMed

    Beshears, John; Choi, James J; Laibson, David; Madrian, Brigitte C

    2008-08-01

    Revealed preferences are tastes that rationalize an economic agent's observed actions. Normative preferences represent the agent's actual interests. It sometimes makes sense to assume that revealed preferences are identical to normative preferences. But there are many cases where this assumption is violated. We identify five factors that increase the likelihood of a disparity between revealed preferences and normative preferences: passive choice, complexity, limited personal experience, third-party marketing, and intertemporal choice. We then discuss six approaches that jointly contribute to the identification of normative preferences: structural estimation, active decisions, asymptotic choice, aggregated revealed preferences, reported preferences, and informed preferences. Each of these approaches uses consumer behavior to infer some property of normative preferences without equating revealed and normative preferences. We illustrate these issues with evidence from savings and investment outcomes. PMID:24761048

  13. How Are Preferences Revealed?

    PubMed Central

    Beshears, John; Choi, James J.; Laibson, David; Madrian, Brigitte C.

    2009-01-01

    Revealed preferences are tastes that rationalize an economic agent’s observed actions. Normative preferences represent the agent’s actual interests. It sometimes makes sense to assume that revealed preferences are identical to normative preferences. But there are many cases where this assumption is violated. We identify five factors that increase the likelihood of a disparity between revealed preferences and normative preferences: passive choice, complexity, limited personal experience, third-party marketing, and intertemporal choice. We then discuss six approaches that jointly contribute to the identification of normative preferences: structural estimation, active decisions, asymptotic choice, aggregated revealed preferences, reported preferences, and informed preferences. Each of these approaches uses consumer behavior to infer some property of normative preferences without equating revealed and normative preferences. We illustrate these issues with evidence from savings and investment outcomes. PMID:24761048

  14. Association of the rs1801133 variant in the MTHFR gene and sporadic Parkinson's disease.

    PubMed

    García, S; Coral-Vázquez, Rm; Gallegos-Arreola, M P; Montes-Almanza, L A; Canto, P; García-Martínez, F A; Chavira-Hernández, G; Palma-Flores, C; Dávila-Maldonado, L; Cuevas-García, C F; López Hernández, L B

    2015-01-01

    The MTHFR gene has been reported as a susceptibility locus for sporadic Parkinson's disease (sPD). The functional variant rs1801133 has been linked to hyperhomocysteinemia and dopaminergic cell death. Among different populations, Mexican-Mestizos (most present-day Mexicans) have the highest frequency of this variant. Therefore, we sought to determine a possible association of rs1801133 with SPD. In total, 356 individuals were included: 140 patients with PD, diagnosed according to the Queen Square Brain Bank criteria, and 216 neurologically healthy controls. Genotyping was performed using TaqMan probes for rs1801133 and real-time PCR. Logistic regression analysis with adjustment for smoking and gender was used to test for an association between genotype and SPD. The CC genotype was associated with SPD; exp() = 2.06; 95% CI: 1.101-3.873, p = 0.024. No association with age at onset, cognitive impairment or gender was found in our study group. Our data suggest an important role of MTHFR gene variants in SPD.

  15. [Sweet syndrome revealing leukemia].

    PubMed

    Elleuch, E; Hammami, B; Smaoui, F; Maaloul, I; Turki, H; Elloumi, M; Ben Jemaa, M

    2011-09-01

    Sweet syndrome is a neutrophilic dermatosis that can lead to various inflammatory and neoplastic pathologies. We report a case of Sweet syndrome revealing acute leukemia at a 13-year-old girl, who had no history of illness. The diagnosis was made in spite of atypical skin lesions and was confirmed by the skin biopsy and the bone marrow examination. In spite of corticosteroid therapy and chemotherapy, the patient died. Sweet syndrome's diagnosis requires an exhaustive etiologic survey. If there is no evidence of underlying disease, patients must be regularly monitored.

  16. The Universe Revealed

    NASA Astrophysics Data System (ADS)

    Spence, Pam

    1998-10-01

    The Universe is a bewildering place to the uninitiated. The concepts and theories that govern space seem complex and often contradictory. The Universe Revealed provides the keys to unlocking the wonders of the cosmos. Elegantly written and lavishly illustrated, it begins with the Sun and stretches through our solar system into deepest space. Lucid prose, written by many of the people who have shaped our current thinking on space, and spectacular photographs make the physics of the Universe accessible and provide a solid background for understanding the most recent astronomical discoveries. Covering the most intriguing features of the cosmos, the topics discussed range from the Earth and global warming to cosmic collisions and the size of the Universe. Major sections examine the Solar System, stars, galaxies, cosmology, and the observational techniques used by astronomers, both amateur and professional. The Universe Revealed represents the collaboration of internationally renowned experts in astronomy and cosmology, with contributions from authors including David Malin, F. Duccio Macchetto, Iain Nicholson, Neil Bone, Ian Ridpath, Seth Shostak, Mike Lancaster, Steve Miller, Ken Croswell, Geoff McNamara, and Steven Young. This extraordinary blend of astronomy, astrophysics, and cosmology, will appeal to amateur and armchair astronomers alike.

  17. Gusev's Rim Revealed

    NASA Technical Reports Server (NTRS)

    2004-01-01

    NASA's Mars Exploration Rover Spirit took this panoramic camera image on sol 91 (April 5, 2004). Spirit is looking to the southeast, and through the martian haze has captured the rim of Gusev Crater approximately 80 kilometers (49.7 miles) away on the horizon.

    The right side of this image reveals the portion of the crater edge that descends into the mouth of Ma'adim Vallis, a channel that opens into Gusev Crater. Spirit is currently traveling toward the informally named 'Columbia Hills,' which lie to the left of the region pictured here.

    This image is similar to a panoramic camera image taken on sol 68, but Gusev's ridge is more visible here because the atmospheric dust caused by winter dust storms has settled. Scientists expect to get even clearer images than this one in upcoming sols.

    This image has been modified to make the crater rim more visible.

  18. The Climate Revealed

    NASA Astrophysics Data System (ADS)

    Burroughs, William

    1999-10-01

    El Niño, La Niña, global warming--terms that crop up frequently in current media coverage of anomalous weather conditions: a spring thaw in January in New York City...a snowstorm in Bakersfield, California...winterlike temperatures in Miami. Such phenomena as these and reports of devastating droughts, floods, and storms around the world bring home the fact of how deeply climate affects our daily lives--and of our inability to control the consequences of climatic events. Extraordinarily timely, The Climate Revealed explores the human-climate "relationship" in all its fascinating complexity. Packed with 250 beautiful, full-color photographs, the volume travels the globe to provide a detailed portrait of individual climate zones from the polar icecaps to the fiercest deserts. The expert and highly accessible text uncovers the essential elements--earth, air, fire and water--that make up the world's various climates. William Burroughs reveals the dramatic discoveries and techniques of historians and archaeologists in their search to understand climates of the past. In the book's conclusion he considers the future and presents every facet of the current environmental debate. With its detailed coverage of the past, present, and future, this marvelous work is essential reading for all those who want to understand one of the most critical facets of life, climate. William Burroughs is a well known and successful science author who has written four books on the weather including Does the Weather Really Matter? (1997), Weather Cycles: Real or Imaginary (1992), and Watching the World's Weather (1991), all published by Cambridge University Press.

  19. Revealing cosmic rotation

    NASA Astrophysics Data System (ADS)

    Yadav, Amit P. S.; Shimon, Meir; Keating, Brian G.

    2012-10-01

    Cosmological Birefringence, a rotation of the polarization plane of radiation coming to us from distant astrophysical sources, may reveal parity violation in either the electromagnetic or gravitational sectors of the fundamental interactions in nature. Until only recently this phenomenon could be probed with only radio observations or observations at UV wavelengths. Recently, there is a substantial effort to constrain such nonstandard models using observations of the rotation of the polarization plane of cosmic microwave background (CMB) radiation. This can be done via measurements of the B-modes of the CMB or by measuring its TB and EB correlations which vanish in the standard model. In this paper we show that EB correlations-based estimator is the best for upcoming polarization experiments. The EB-based estimator surpasses other estimators because it has the smallest noise and of all the estimators is least affected by systematics. Current polarimeters are optimized for the detection of B-mode polarization from either primordial gravitational waves or by large-scale structures via gravitational lensing. In the paper we also study the optimization of CMB experiments for the detection of cosmological birefringence, in the presence of instrumental systematics, which by themselves are capable of producing EB correlations, potentially mimicking cosmological birefringence.

  20. Killer-cell immunoglobulin-like receptors and cytomegalovirus reactivation during late pregnancy.

    PubMed

    Alvarado-Hernández, D L; Benítez-Sánchez, A; Rodríguez-Cuevas, J S; Rosales-Saavedra, T; Guerra-Palomares, S E; Comas-García, A; Noyola, D E; García-Sepúlveda, C A

    2016-08-01

    Human cytomegalovirus (CMV) represents an important public health concern as it is associated with severe morbidity and mortality in transplant recipients, HIV-infected individuals and pregnant women given the risk of congenital infection. Congenital CMV is a leading cause of neurological sequelae, developmental delay and birth defects worldwide. Cytomegalovirus can be transmitted to the foetus following maternal infection or reactivation. NK cells expressing killer-cell immunoglobulin-like receptors (KIR) are part of the innate immune system and the first line of defence against viral incursions. Previous reports have shown that KIR genes are associated with CMV infections in the post-transplant setting. In this study, we set out to determine whether a protective effect of KIR genes over CMV infection is seen in Mexican pregnant women. Cytomegalovirus infection was assessed through nucleic acid testing in 200 pregnant women and 600 healthy blood donors comprising the Mexican mestizo reference population. Killer-cell immunoglobulin-like receptors and HLA-C genotypes were obtained from 200 pregnant women and 300 reference samples using a comprehensive PCR-SSP approach. We observed statistically lower carrier frequencies of cB03|tA01 gene-content haplotype, of cB03 haplotype motif, of the KIR2DL5 + 2DS3/2DS5 gene pair and of KIR2DL5 amongst CMV-positive pregnant women in comparison with those CMV negative. None of these were associated with CMV status in the reference population. Logistic regression analysis revealed that the most important factor determining CMV status during third-trimester pregnancies was the KIR2DL5 + 2DS3/2DS5 gene pair (OR 0.376 (95%CI 0.174, 0.811, P = 0.013). Our results indicate that CMV-protective KIR gene associations described in Caucasoid populations are also present in the genetically distinct Mexican mestizo population. Our results suggest that certain KIR gene combinations provide protection against CMV infections occurring

  1. CFH haplotypes and ARMS2, C2, C3, and CFB alleles show association with susceptibility to age-related macular degeneration in Mexicans

    PubMed Central

    Zenteno, Juan Carlos; Fernández-López, Juan Carlos; Rodríguez-Corona, Ulises; Falfán-Valencia, Ramcés; Sebastian, Leticia; Morales, Fabiola; Ochoa-Contreras, Daniel; Carnevale, Alessandra; Silva-Zolezzi, Irma

    2014-01-01

    Purpose To evaluate the contribution of genetic variants of complement factor H (CFH), complement component 2 and 3 (C2 and C3), complement factor B (CFB), and age-related maculopathy susceptibility 2 (ARMS2) to age-related macular degeneration (AMD) risk in the Mexican Mestizo population. Methods Analysis included 282 unrelated Mexican patients with advanced AMD, 205 healthy controls, and 280 population controls. Stereoscopic fundus images were graded on the Clinical Age-Related Maculopathy System (CARMS). We designed a resequencing strategy using primers with M13 adaptor for the 23 exons of the CFH gene in a subgroup of 96 individuals clinically evaluated: 48 AMD cases and 48 age- and sex-matched healthy controls. Single nucleotide polymorphisms (SNPs) in C3 (Arg80Gly and Pro292Leu), C2 (rs547154), CFB (Leu9His), and ARMS2 (Ala69Ser) were genotyped in all patients, healthy and population controls using TaqMan assay. Results All evaluated individuals were Mexican Mestizos, and their genetic ancestry was validated using 224 ancestry informative markers and calculating Fst values. The CFH resequencing revealed 19 SNPs and a common variant in the intron 2 splice acceptor site; three CFH haplotypes inferred from individual genotypes, showed significant differences between cases and controls. The risk alleles in C3 (rs1047286, odds ratio [OR]=2.48, 95% confidence interval [CI]=1.64–3.75, p=1.59E-05; rs2230199, OR=2.15, 95% CI=1.48–3.13, p=6.28E-05) and in ARMS2 (rs10490924, OR=3.09, 95% CI=2.48–3.86, p=5.42E-23) were strongly associated with risk of AMD. The protective effect of alleles in C2 (rs547154) and CFB (rs4151667) showed a trend but was not significantly associated after correction for multiple testing. Conclusions Our results show that ARMS2 and C3 are major contributors to advanced AMD in Mexican patients, while the contributions of CFH, C2, and CFB are minor to those of other populations, reveling significant ethnic differences in minor allele

  2. Titan Casts Revealing Shadow

    NASA Astrophysics Data System (ADS)

    2004-05-01

    A rare celestial event was captured by NASA's Chandra X-ray Observatory as Titan -- Saturn's largest moon and the only moon in the Solar System with a thick atmosphere -- crossed in front of the X-ray bright Crab Nebula. The X-ray shadow cast by Titan allowed astronomers to make the first X-ray measurement of the extent of its atmosphere. On January 5, 2003, Titan transited the Crab Nebula, the remnant of a supernova explosion that was observed to occur in the year 1054. Although Saturn and Titan pass within a few degrees of the Crab Nebula every 30 years, they rarely pass directly in front of it. "This may have been the first transit of the Crab Nebula by Titan since the birth of the Crab Nebula," said Koji Mori of Pennsylvania State University in University Park, and lead author on an Astrophysical Journal paper describing these results. "The next similar conjunction will take place in the year 2267, so this was truly a once in a lifetime event." Animation of Titan's Shadow on Crab Nebula Animation of Titan's Shadow on Crab Nebula Chandra's observation revealed that the diameter of the X-ray shadow cast by Titan was larger than the diameter of its solid surface. The difference in diameters gives a measurement of about 550 miles (880 kilometers) for the height of the X-ray absorbing region of Titan's atmosphere. The extent of the upper atmosphere is consistent with, or slightly (10-15%) larger, than that implied by Voyager I observations made at radio, infrared, and ultraviolet wavelengths in 1980. "Saturn was about 5% closer to the Sun in 2003, so increased solar heating of Titan may account for some of this atmospheric expansion," said Hiroshi Tsunemi of Osaka University in Japan, one of the coauthors on the paper. The X-ray brightness and extent of the Crab Nebula made it possible to study the tiny X-ray shadow cast by Titan during its transit. By using Chandra to precisely track Titan's position, astronomers were able to measure a shadow one arcsecond in

  3. Revealing the Beast Within

    NASA Astrophysics Data System (ADS)

    2003-07-01

    Deeply Embedded Massive Stellar Clusters Discovered in Milky Way Powerhouse Summary Peering into a giant molecular cloud in the Milky Way galaxy - known as W49 - astronomers from the European Southern Observatory (ESO) have discovered a whole new population of very massive newborn stars . This research is being presented today at the International Astronomical Union's 25th General Assembly held in Sydney, Australia, by ESO-scientist João Alves. With the help of infrared images obtained during a period of excellent observing conditions with the ESO 3.5-m New Technology Telescope (NTT) at the La Silla Observatory (Chile), the astronomers looked deep into this molecular cloud and discovered four massive stellar clusters, with hot and energetic stars as massive as 120 solar masses. The exceedingly strong radiation from the stars in the largest of these clusters is "powering" a 20 light-year diameter region of mostly ionized hydrogen gas (a "giant HII region"). W49 is one of the most energetic regions of star formation in the Milky Way. With the present discovery, the true sources of the enormous energy have now been revealed for the first time, finally bringing to an end some decades of astronomical speculations and hypotheses. PR Photo 21a/03 : Colour Composite of W49A (NTT+SOFI). PR Photo 21b/03 : Radio and Near-Infrared Composite of W49A Giant molecular clouds Stars form predominantly inside Giant Molecular Clouds which populate our Galaxy, the Milky Way. One of the most prominent of these is W49 , which has a mass of a million solar masses. It is located some 37,000 light-years away and is the most luminous star-forming region known in our home galaxy: its luminosity is several million times the luminosity of our Sun. A smaller region within this cloud is denoted W49A - this is one of the strongest radio-emitting areas known in the Galaxy . Massive stars are excessive in all ways. Compared to their smaller and ligther brethren, they form at an Olympic speed and

  4. Present-day challenges and future solutions in postoperative pain management: results from PainForum 2014

    PubMed Central

    Kuusniemi, Kristiina; Pöyhiä, Reino

    2016-01-01

    This paper is a summary of presentations on postoperative pain control by the authors at the 2014 PainForum meeting in People’s Republic of China. Postoperative pain is often untreated or undertreated and may lead to subsequent chronic pain syndromes. As more procedures migrate to the outpatient setting, postoperative pain control will become increasingly more challenging. Evidence-based guidelines for postoperative pain control recommend pain assessment using validated tools on a consistent basis. In this regard, consistency may be more important than the specific tool selected. Many hospitals have introduced a multidisciplinary acute pain service (APS), which has been associated with improved patient satisfaction and fewer adverse events. Patient education is an important component of postoperative pain control, which may be most effective when clinicians chose a multimodal approach, such as paracetamol (acetaminophen) and opioids. Opioids are a mainstay of postoperative pain control but require careful monitoring and management of side effects, such as nausea, vomiting, dizziness, and somnolence. Opioids may be administered using patient-controlled analgesia systems. Protocols for postoperative pain control can be very helpful to establish benchmarks for pain management and assure that clinicians adhere to evidence-based standards. The future of postoperative pain control around the world will likely involve more and better established APSs and greater communication between patients and clinicians about postoperative pain. The changes necessary to implement and move forward with APSs is not a single step but rather one of continuous improvement and ongoing change. PMID:26893579

  5. A complicated story of frost and wind: Present-day gully activity within the north polar erg, Mar

    NASA Astrophysics Data System (ADS)

    Diniega, Serina; Hansen, Candice; Allen, Amanda; Grisby, Nathan; Li, Zheyu Joey

    2016-10-01

    Analyses of high-resolution observations have shown that the dunes within the martian north polar erg (AKA Olympia Undae) are currently very active on seasonal and yearly timescales, with 20-60% of the dunes within five polar dune fields undergoing the formation of alcove-apron features each Mars year. Previous studies have hypothesized formation mechanisms, based on observations of when new alcove and alcove-apron features form within an individual field through one Mars year. However, results are ill-constrained (and thus different hypotheses have been proposed) as the polar hood and winter night mean very few images are taken during the actual period of activity. In this study, we mitigate this limitation by examining several fields over several Mars years -- thus bringing aggregated results as well as detailed correlation checks against environmental conditions and seasonal processes to bear on the problem. From this, we propose a new process that appears consistent with all observations: (1) small alcoves form along the dune brink in the autumn (under the polar hood) due to instabilities induced by the night-formation and morning-sublimation of frost. As autumn progresses, the seasonal frost layer builds over the altered dune slope. (2) In the early spring, sublimation activity is concentrated and/or enhanced over these alcoves, causing further erosion and the formation of larger alcove-apron features. From the planform dimensions of the newly formed alcoves, we can estimate the volume of sand moved down the dune slope during one period of activity and estimate the aeolian sediment flux by looking at how quickly the alcoves are erased. We find that, over a Mars year, the amount of material moved via alcove-apron activity and via the wind are both comparable to aeolian sand flux estimates over dunes within lower-latitude regions of Mars. Thus it appears that the formation of alcoves-aprons is a significant mechanism for dune advancement and evolution within the north polar erg, and understanding it better will add to our understanding of polar processes, aeolian sediment transport, and dune evolution on Mars.

  6. Evidence and ideology as a rationale for light-therapy in Russia: from the Soviet Union to the present day.

    PubMed

    Kühlbrandt, Charlotte; McKee, Martin

    2013-07-01

    Light therapy is still used to treat a number of common diseases in Russia. The practice is firmly anchored in history: Soviet clinical practice was divorced from the emerging field of evidence-based medicine. Medical researchers were cut off from international medical research and scientific literature, with much Soviet scientific activity based on a particular socialist ideology. In this study, the use of light therapy serves as a case study to explore tensions between international evidence-based medicine and practices developed in isolation under the Soviet Union, the legacy of which is to the detriment of many patients today. We used four different search methods to uncover scientific and grey literature, both historical and contemporary. We assessed the changing frequency of publications over time and contrasted the volume of literature on light therapy with more orthodox treatments such as statins and painkillers. Our search found an increasing number and comparatively large body of scientific publications on light therapy in the Russian language, and many publications emanating from prestigious Russian institutions. Combined with our analysis of the historical literature and our appraisal of 22 full text articles, this leads us to suggest that light therapy entered mainstream Soviet medical practice before the Stalinist period and still occupies an important position in contemporary Russian clinical practice. We propose that this outdated treatment survives in Russia in part due to the political, economic and social forces that helped to popularize it during Soviet times, and by the seeming justification offered by poorly executed studies.

  7. Stable lead isotope compositions in selected coals from around the world and implications for present day aerosol source tracing.

    PubMed

    Díaz-Somoano, M; Kylander, M E; López-Antón, M A; Suárez-Ruiz, I; Martínez-Tarazona, M R; Ferrat, M; Kober, B; Weiss, D J

    2009-02-15

    The phasing out of leaded gasoline in many countries around the world at the end of the last millennium has resulted in a complex mixture of lead sources in the atmosphere. Recent studies suggest that coal combustion has become an important source of Pb in aerosols in urban and remote areas. Here, we report lead concentration and isotopic composition for 59 coal samples representing major coal deposits worldwide in an attempt to characterize this potential source. The average concentration in these coals is 35 microg Pb g(-1), with the highest values in coals from Spain and Peru and the lowest in coals from Australia and North America. The 206Pb/207Pb isotope ratios range between 1.15 and 1.24, with less radiogenic Pb in coals from Europe and Asia compared to South and North America. Comparing the Pb isotopic signatures of coals from this and previous studies with those published for Northern and Southern Hemisphere aerosols, we hypothesize that coal combustion might now be an important Pb source in China, the eastern U.S., and to some extent, in Europe but not as yet in other regions including South Africa, South America, and western U.S. This supports the notion that "old Pb pollution" from leaded gasoline reemitted into the atmosphere or long-range transport (i.e., from China to the western U.S.) is important. Comparing the isotope ratios of the coals, the age of the deposits, and Pb isotope evolution models for the major geochemical reservoirs suggests that the PbIC in coals is strongly influenced by the depositional coal forming environment.

  8. An enquiry into theoretical bioinorganic chemistry: how heuristic is the character of present-day quantum chemical methods?

    PubMed

    Podewitz, Maren; Stiebritz, Martin T; Reiher, Markus

    2011-01-01

    In this discussion we elaborate on the state of the art in computational bioinorganic chemistry and aim at identifying and defining the most difficult obstacles in the process of obtaining unambiguous and predictive results from quantum chemical calculations. We then proceed to discuss and analyse well-known as well as new concepts for overcoming some of these obstacles.

  9. Present-day oxidative subsidence of organic soils and mitigation in the Sacramento-San Joaquin Delta, California, USA.

    PubMed

    Deverel, Steven J; Ingrum, Timothy; Leighton, David

    L’affaissement des sols organiques dans le Delta de Sacramento-San Joaquin menace la durabilité du système d’approvisionnement en eau et de l’agriculture de la Californie (Etats-Unis d’Amérique). Des données d’altitude de la surface topographique ont été collectées dans le but d’estimer le taux d’affaissement actuel des sols et d’évaluer l’occupation des sols par des rizières en tant que moyen d’atténuation de l’affaissement des sols. Pour décrire les taux actuels d’affaissement des sols à l’échelle du Delta, le modèle SUBCALC développé précédemment a été affiné et calé grâce à l’utilisation des données récentes sur les émissions de CO2 et des variations d’altitude de la surface topographique enregistrées par des extensomètres. Les données de variations d’altitude de la surface topographique ont été évaluées par rapport aux estimations indirectes de l’affaissement du sol et de son accroissement basées sur les données de flux de carbone et d’azote au niveau des rizières. Les données d’extensiométrie et de nivellement montrent que les variations saisonnières de l’altitude de la surface topographique associées aux fluctuations des niveaux piézométriques et des taux d’affaissement inélastique du sol compris entre 0.5 et 0.8 cm an(–1). Le calage du modèle SUBCALC indique une précision de ±0.10 cm an (–1) là où la profondeur de la nappe, la teneur en matière organique du sol et la température sont connues. Les estimations régionales de l’affaissement du sol sont compris entre <0.3 à >1.8 cm an(–1). L’incertitude principale est la distribution de la teneur en matière organique du sol qui conduit à un lissage spatial dans la cartographie des taux d’affaissement des sols. L’analyse des données de nivellement et d’extensiométrie dans les rizières conduit à un taux d’accroissement estimé entre 0.02 et 0.8 cm an(–1). Ces valeurs sont généralement en accord avec les estimations indirectes basées sur les flux de carbone et de la minéralisation de l’azote qui indiquent a priori que le riz stoppera ou réduira de manière substantielle l’affaissement du sol. Les zones d’altitude inférieure à –2 m sont des zones candidates pour la mise en œuvre de mesures d’atténuation telles que la culture du riz car il s’y produit un affaissement du sol actif avec des taux supérieurs à 0.4 cm an(–1).

  10. Utilizing DNA analysis to combat the world wide plague of present day slavery – trafficking in persons

    PubMed Central

    Palmbach, Timothy; Blom, Jeffrey; Hoynes, Emily; Primorac, Dragan; Gaboury, Mario

    2014-01-01

    A study was conducted to determine if modern forensic DNA typing methods can be properly employed throughout the world with a final goal of increasing arrests, prosecutions, and convictions of perpetrators of modern day trafficking in persons while concurrently reducing the burden of victim testimony in legal proceedings. Without interruption of investigations, collection of samples containing DNA was conducted in a variety of settings. Evidentiary samples were analyzed on the ANDE Rapid DNA system. Many of the collected swabs yielded informative short tandem repeat profiles with Rapid DNA technology. PMID:24577820

  11. [Impact of present-day forms of organization of physical education on the health status of preschool children].

    PubMed

    Kuchma, V R; Vishnevskaia, T Iu; Makarova, A Iu

    2006-01-01

    During a natural hygienic experiment, the physical development, psychomotor activity, exercise performance, and readiness were evaluated in 6-year-old children, in whom physical education had been organized by routine and experimental programs, including health-improving swimming in the indoor pool of a preschool educational establishment. Exercises built up on the principle of plot-role playing games, by using the developing corrective exercises and psychological and pedagogical escort, were established to be highly effective. The proposed methods contribute to the timely harmonious development of a child, his movement characteristics, positively affect the neurofunctional status, by ensuring the optimum psychomotor development, and maintain a high exercise performance.

  12. Studies of volatiles and organic materials in early terrestrial and present-day outer solar system environments

    NASA Technical Reports Server (NTRS)

    Sagan, Carl; Thompson, W. Reid; Chyba, Christopher F.; Khare, B. N.

    1991-01-01

    A review and partial summary of projects within several areas of research generally involving the origin, distribution, chemistry, and spectral/dielectric properties of volatiles and organic materials in the outer solar system and early terrestrial environments are presented. The major topics covered include: (1) impact delivery of volatiles and organic compounds to the early terrestrial planets; (2) optical constants measurements; (3) spectral classification, chemical processes, and distribution of materials; and (4) radar properties of ice, hydrocarbons, and organic heteropolymers.

  13. Understanding our love affair with p-chlorophenyl: present day implications from historical biases of reagent selection.

    PubMed

    Brown, Dean G; Gagnon, Moriah M; Boström, Jonas

    2015-03-12

    We report here an unexpectedly strong preference toward para substitution in phenyl rings within drug discovery programs. A population analysis of aromatic rings in various drug databases demonstrated that para substitution is favored over meta and ortho regioisomers, with p-chlorophenyl (p-ClPh) being one of the most predominant examples. We speculate that the frequency of p-ClPh is traced back to historical models of medicinal chemistry where para-substituted regioisomers were perhaps more easily accessed, and further reinforced by Topliss in 1972 that if Ph was active, the p-ClPh should be made because of ease of synthesis and hydrophobicity driven potency effects. On the basis of our analysis, the para bias has become useful conventional wisdom but perhaps so much so that a perception has been created that druglike space favors a linear aromatic structure. It is hoped this analysis will catalyze a new look at design of reagent databases and screening collections.

  14. A Lagrangian analysis of the present-day sources of moisture for major ice-core sites

    NASA Astrophysics Data System (ADS)

    Drumond, Anita; Taboada, Erica; Nieto, Raquel; Gimeno, Luis; Vicente-Serrano, Sergio M.; López-Moreno, Juan Ignacio

    2016-07-01

    A Lagrangian approach was used to identify the moisture sources for 14 ice-core sites located worldwide for the period of 1980-2012. The sites were classified into three domains: Arctic, Central (Andes, Alps, and Kilimanjaro), and Antarctic. The approach was used to compute budgets of evaporation minus precipitation by calculating changes in the specific humidity along 10-day backward trajectories. The results indicate that the oceanic regions around the subtropical high-pressure centres provide most of moisture, and their contribution varies throughout the year following the annual cycles of the centres. For the Arctic Domain, the sources lie in the subtropical North Atlantic and Pacific. The subtropical South Atlantic, Indian, and Pacific oceans provide moisture for the Antarctic Domain. The sources for South America are the Atlantic and South Pacific, for Europe the sources are in the Mediterranean and the North Atlantic, and for Asia the sources are the Indian Ocean and the Arabian Sea.

  15. Geometry of structures within crystalline bedrock constrained in 3D and their relevance for present day water infiltration.

    NASA Astrophysics Data System (ADS)

    Schneeberger, Raphael; de la Varga, Miguel; Florian Wellmann, J.; Kober, Florian; Berger, Alfons; Herwegh, Marco

    2016-04-01

    Fluid circulation in crystalline rocks is of key importance when exploring crystalline basement in light of, for example, deep-seated geothermal energy projects or selection of sites for nuclear waste repositories. Due to their enhanced permeability, fluid circulation within crystalline bedrock is mainly controlled by fault zones, which may originate from ductile mylonites but show a strong brittle overprint. In order to better constrain 3D flow paths, a well-founded knowledge on the 3D nature of the fault zone pattern is indispensable. We attempt to constrain the geometry of a complex 3D fault zone pattern in a case study of the Grimsel Test Site (GTS, central Switzerland). The constraints are based on mapping of both the surface as well as the GTS underground tunnel system, offering a unique opportunity to test the 3D model and associated uncertainties. We investigate the effect of increasing geoinformation on the quality and accuracy of the 3D model by using: (i) remote sensing surface data only, (ii) field surface mapping in combination with (i), and (iii) underground data combined with (i) and (ii). This approach allows for defining different steps in 3D geological modelling of a specific area, including a measure of the remaining uncertainty after each step. We obtain a best-estimate model by fitting results between surface and underground data by using a combination of field data and orientation obtained by Delaunay triangulation. We incorporate novel approaches to uncertainty analysis of fault orientations and investigate different fault planes showing the possible variation range of the structures investigated.

  16. Modeling of present-day atmosphere and ocean non-tidal de-aliasing errors for future gravity mission simulations

    NASA Astrophysics Data System (ADS)

    Dobslaw, Henryk; Bergmann-Wolf, Inga; Forootan, Ehsan; Dahle, Christoph; Mayer-Gürr, Torsten; Kusche, Jürgen; Flechtner, Frank

    2016-05-01

    A realistically perturbed synthetic de-aliasing model consistent with the updated Earth System Model of the European Space Agency is now available over the period 1995-2006. The dataset contains realizations of (1) errors at large spatial scales assessed individually for periods 10-30, 3-10, and 1-3 days, the S1 atmospheric tide, and sub-diurnal periods; (2) errors at small spatial scales typically not covered by global models of atmosphere and ocean variability; and (3) errors due to physical processes not represented in currently available de-aliasing products. The model is provided in two separate sets of Stokes coefficients to allow for a flexible re-scaling of the overall error level to account for potential future improvements in atmosphere and ocean mass variability models. Error magnitudes for the different frequency bands are derived from a small ensemble of four atmospheric and oceanic models. For the largest spatial scales up to d/o = 40 and periods longer than 24 h, those error estimates are approximately confirmed from a variance component estimation based on GRACE daily normal equations. Future mission performance simulations based on the updated Earth System Model and the realistically perturbed de-aliasing model indicate that for GRACE-type missions only moderate reductions of de-aliasing errors can be expected from a second satellite pair in a shifted polar orbit. Substantially more accurate global gravity fields are obtained when a second pair of satellites in an moderately inclined orbit is added, which largely stabilizes the global gravity field solutions due to its rotated sampling sensitivity.

  17. Paleobotanical Evidence for Near Present-Day Levels of Atmospheric CO2 During Part of the Tertiary

    NASA Astrophysics Data System (ADS)

    Royer, Dana L.; Wing, Scott L.; Beerling, David J.; Jolley, David W.; Koch, Paul L.; Hickey, Leo J.; Berner, Robert A.

    2001-06-01

    Understanding the link between the greenhouse gas carbon dioxide (CO2) and Earth's temperature underpins much of paleoclimatology and our predictions of future global warming. Here, we use the inverse relationship between leaf stomatal indices and the partial pressure of CO2 in modern Ginkgo biloba and Metasequoia glyptostroboides to develop a CO2 reconstruction based on fossil Ginkgo and Metasequoia cuticles for the middle Paleocene to early Eocene and middle Miocene. Our reconstruction indicates that CO2 remained between 300 and 450 parts per million by volume for these intervals with the exception of a single high estimate near the Paleocene/Eocene boundary. These results suggest that factors in addition to CO2 are required to explain these past intervals of global warmth.

  18. Landau ghost pole problem in quantum field theory: From 50th of last century to the present day

    NASA Astrophysics Data System (ADS)

    Jafarov, Rauf G.; Mutallimov, Mutallim M.

    2016-03-01

    In this paper we present our results of the investigation of asymptotical behavior of amplitude at short distances in four-dimensional scalar field theory with ϕ4 interaction. To formulate of our calculating model - two-particle approximation of the mean-field expansion we have used an Rochev's iteration scheme of solution of the Schwinger-Dyson equations with the fermion bilocal source. We have considered the nonlinear integral equations in deep-inelastic region of momenta. As result we have a non-trivial behavior of amplitude at large momenta.

  19. Ductile deformation, boudinage and low angle normal faults. An overview of the structural variability at present-day rifted margins

    NASA Astrophysics Data System (ADS)

    Clerc, Camille; Jolivet, Laurent; Ringenbach, Jean-Claude; Ballard, Jean-François

    2016-04-01

    High quality industrial seismic profiles acquired along most of the world's passive margins present stunningly increased resolution that leads to unravel an unexpected variety of structures. An important benefit of the increased resolution of recent seismic profiles is that they provide an unprecedented access to the processes occurring in the middle and lower continental crust. We present a series of so far unreleased profiles that allow the identification of various rift-related geological processes such as crustal boudinage, ductile shear and low angle detachment faulting. The lower crust in passive margins appears much more intensely deformed than usually represented. At the foot of both magma-rich and magma-poor margins, we observe clear indications of ductile deformation of the deep continental crust along large-scale shallow dipping shear zones. These shear zones generally show a top-to-the-continent sense of shear consistent with the activity of overlying continentward dipping normal faults observed in the upper crust. This pattern is responsible for a migration of the deformation and associated sedimentation and/or volcanic activity toward the ocean. In some cases, low angle shear zones define an anastomosed pattern that delineates boudin-like structures. The interboudins areas seem to localize the maximum of deformation. The lower crust is intensely boudinaged and the geometry of those boudins seems to control the position and dip of upper crustal normal faults. We present some of the most striking examples (Uruguay, West Africa, Barents sea…) and discuss their implications for the time-temperature-subsidence history of the margins.

  20. [The model of state health policy and the system of medical assistance adopted in present-day Brazil].

    PubMed

    Queiroz, M de S; Vianna, A L

    1992-04-01

    A contribution to the analysis of the health reform presently occurring in Brazil is presented. The need to consolidate the theoretical background which supports the advances already achieved in order to understand recent events in the area is stressed. In this regard, the health reform is understood as a question transcending the mere administrative and managerial aspect of the health system, since it necessarily involves a redefinition of the concepts of health, disease and the medical practice adopted by the dominant mechanistic paradigm of medicine. The recent events which delineate the health system in Brazil are analysed and criticised in the light of this concern.

  1. [Early signs of the influence of harmful industrial factors on workers at present-day petrochemical plants].

    PubMed

    Karimova, L K; Gizatullina, D F

    2012-01-01

    The working conditions and health status were studied in workers from different petrochemical plants. The leading industrial factors that conferred moderate and high risks of health impairments as early signs of the combined action of harmful substances and industrial noise, as well as mild occupational diseases were identified in the workers of essential trades at the petrochemical plants. According to the results of the investigation, the authors have elaborated a package of measures to promote the health status of workers at the petrochemical plants.

  2. Present-day kinematics of the eastern Tibetan Plateau and Sichuan Basin: Implications for lower crustal rheology

    NASA Astrophysics Data System (ADS)

    Rui, X.; Stamps, D. S.

    2016-05-01

    The Sichuan Province comprises the cratonic Sichuan Basin and the eastern Tibetan Plateau separated by the recently activated Longmen Shan fault zone, thus providing a natural laboratory to study interseismic and postseismic processes. In this work we compute a new regional geodetic velocity solution from most of the continuous Global Navigation Satellite Systems (GNSS)/GPS data available in the Sichuan Province that we assess for transient postseismic deformation. For 11 continuous sites in close proximity to the Wenchuan 2008 event epicenter that were operational during the Wenchuan event we find an average short-term relaxation time of 11 days with maximum amplitude of 6.6 mm for the postseismic transient and no resolvable long-term transient. Using tests for block rigidity guided by previous kinematic studies we elucidate a longer-term transient in GNSS/GPS observations collected after the Wenchuan event that spans an extensive region of the eastern Tibetan Plateau. We correct for transients, produce an updated secular velocity field, and revise the kinematics of the region using elastic block modeling. Our results indicate that predicted slip rates are in good agreement with both geological and GNSS/GPS velocity profile-derived results, and we resolve two independent blocks with the expanded GNSS/GPS data set. Our constraints on the spatial extent of long-term postseismic deformation support models of ductile lower crust in the eastern margin of the Tibetan Plateau.

  3. FY 2011 Second Quarter: Demonstration of New Aerosol Measurement Verification Testbed for Present-Day Global Aerosol Simulations

    SciTech Connect

    Koch, D

    2011-03-20

    The regional-scale Weather Research and Forecasting (WRF) model is being used by a DOE Earth System Modeling (ESM) project titled “Improving the Characterization of Clouds, Aerosols and the Cryosphere in Climate Models” to evaluate the performance of atmospheric process modules that treat aerosols and aerosol radiative forcing in the Arctic. We are using a regional-scale modeling framework for three reasons: (1) It is easier to produce a useful comparison to observations with a high resolution model; (2) We can compare the behavior of the CAM parameterization suite with some of the more complex and computationally expensive parameterizations used in WRF; (3) we can explore the behavior of this parameterization suite at high resolution. Climate models like the Community Atmosphere Model version 5 (CAM5) being used within the Community Earth System Model (CESM) will not likely be run at mesoscale spatial resolutions (10–20 km) until 5–10 years from now. The performance of the current suite of physics modules in CAM5 at such resolutions is not known, and current computing resources do not permit high-resolution global simulations to be performed routinely. We are taking advantage of two tools recently developed under PNNL Laboratory Directed Research and Development (LDRD) projects for this activity. The first is the Aerosol Modeling Testbed (Fast et al., 2011b), a new computational framework designed to streamline the process of testing and evaluating aerosol process modules over a range of spatial and temporal scales. The second is the CAM5 suite of physics parameterizations that have been ported into WRF so that their performance and scale dependency can be quantified at mesoscale spatial resolutions (Gustafson et al., 2010; with more publications in preparation).

  4. Glacial meltwater cooling of the Gulf of Mexico - GCM implications for Holocene and present-day climates

    NASA Technical Reports Server (NTRS)

    Oglesby, Robert J.; Maasch, Kirk A.; Saltzman, Barry

    1989-01-01

    The NCAR Community Climate Model GCM is presently used to investigate the possible effects on regional and hemispheric climates of reduced SSTs in the Gulf of Mexico, in view of delta-O-18 records and terrestrial evidence for at least two major glacial meltwater discharges after the last glacial maximum. Three numerical experiments have been conducted with imposed gulfwide SST coolings of 3, 6, and 12 C; in all cases, significant reductions arise in the North Atlantic storm-track intensity, together with a strong decrease in transient eddy water vapor transport out of the Gulf of Mexico. Other statistically significant changes occur across the Northern Hemisphere.

  5. The anthropogenic nature of present-day low energy rivers in western France and implications for current restoration projects

    NASA Astrophysics Data System (ADS)

    Lespez, L.; Viel, V.; Rollet, A. J.; Delahaye, D.

    2015-12-01

    As in other European countries, western France has seen an increase in river restoration projects. In this paper, we examine the restoration goals, methods and objectives with respect to the long-term trajectory and understanding of the contemporary dynamics of the small low energy rivers typical of the lowlands of Western Europe. The exhaustive geomorphological, paleoenvironmental and historical research conducted in the Seulles river basin (Normandy) provides very accurate documentation of the nature and place of the different legacies in the fluvial systems we have inherited. The sedimentation rate in the Seulles valley bottom has multiplied by a factor of 20 since the end of the Bronze Age and has generated dramatic changes in fluvial forms. Hydraulic control of the rivers and valley bottoms drainage throughout the last millennium has channelized rivers within these deposits. The single meandering channel which characterizes this river today is the legacy of the delayed and complex effects of long term exploitation of the river basin and the fluvial system. Bring to light that the "naturalness" of the restored rivers might be questioned. Our research emphasizes the gap between the poor knowledge of the functioning of these rivers and the concrete objectives of the restoration works undertaken, including dam and weir removal. Account of the long-term history of fluvial systems is required, not only to produce a pedagogic history of the "river degradation" but more fundamentally (i) to situate the current functioning of the fluvial system in a trajectory to try to identify thresholds and anticipate the potential turning points in a context of climate and land use change, (ii) to understand the role of morphosedimentary legacies on the current dynamics, (iii) to open the discussion on reference functioning or expected states and (iv) to open discussion on the sustainability of ecological restoration. To conclude, we point out the necessity to take into account the hybrid nature of low energy rivers in rural environments and to develop specific evaluation protocols which would include both biophysical processes and usual human activities which could be a way to share the evaluation and overcome conflicts between socioeconomic needs and environmental issues.

  6. Reversing Present Day Northern Plains Ecosystem Water Supply Stressors Resulting from the Near Extinction of Three Keystone Species

    NASA Astrophysics Data System (ADS)

    Collins, M. R.

    2006-05-01

    Near-extinction of three keystone species (the beaver, the bison, and the prairie dog) had a measurable negative influence on the local and regional climate, and water availability in the Northern Great Plains ecosystem compared to pre-contact conditions. Restoration of these three keystone species may have a significant positive influence by increasing the recharge rate to the aquifers and raising soil moisture due to the sharp hooves and wallows of the bison, prairie dog burrows, and beaver dams providing avenues of ingress. Predictions 1) The recharge of the aquifer will be greater where these three keystone species are present because of the prairie dog burrows, buffalo hooves and wallows, and beaver dams in comparison to the control area; 2) The entire ecosystem will be rejuvenated where the three species are permitted to return; 3) The microclimate changes caused by this reintroduction will stimulate an observable, measurable improvement in water supply when allowed to proceed to near pre-contact conditions. Next Steps 1) Inventory research area containing bison, prairie dog, and beaver versus control plot. (keystone species absent). 2) Measure the soil moisture, water table, water influx rates. 3) Monitor changes over time. 4) Later phase manipulation: Beaver re-introduction into severely damaged riparian area. 5) Link to Northern Plains NEON Initiative. Current Activity 1. Candidate study locations on Standing Rock reservation have been selected and evaluated for suitability, both as study site with beaver activity and a control site with beaver absent. 2. Research mentor identified and selected. Dr. Carol Johnston of South Dakota State University, Director of the Center for Biocomplexity Studies has graciously agreed to oversee my research project 3. Review of previous work is nearing completion. 4. Tribal Agency personnel currently involved with research related to the three keystone species have been interviewed and information obtained from them regarding prairie dog behavior and burrow morphology.

  7. Present-Day Kinematics of the Dead Sea Transform and Internal Deformation within the Sinai and Arabian Plates

    NASA Astrophysics Data System (ADS)

    Gomez, F. G.; Yassminh, R.; Cochran, W. J.; Reilinger, R. E.; Barazangi, M.

    2015-12-01

    An updated GPS velocity field along the Dead Sea Fault (DSF) provides a basis for assessing off-transform strain within the Sinai and Arabian plates along entire length of this left-lateral, continental transform. As one of the main tectonic elements in the eastern Mediterranean region, an improved kinematic view of the DSF elucidates the broader understanding of the regional tectonic framework, as well as contributes to refining the earthquake hazard assessment. Reconciling short-term (geodetic) measurements of crustal strain with neotectonic data on fault movements can yield insight into the mechanical and rheological properties of crustal deformation associated with transform tectonics. In addition to regional continuous GPS stations, this study assembles results from campaign GPS networks in Syria, Lebanon, and Jordan spanning more than a decade. 1-sigma uncertainties on velocities range from less than 0.4 mm/yr (continuous stations and older GPS survey sites) to about 1.0 mm/yr (newer survey sites). Analyses using elastic block models suggest slip rates of 4.0 - 5.0 mm/yr along the southern and central DSF and slip rates of 2.0 - 3.0 mm/yr along the northern DSF, and fault locking depths also vary along strike of the transform. Furthermore, the spatial distribution of GPS observations permits analyzing residual strains within the adjacent plates, after plate boundary strain is removed. A key observation is horizontal stretching within the Sinai plate, which may be related to pull by the subducted slab of the Sinai plate. Within the Arabian plate, areas of horizontal stretching generally correlate with locations of Quaternary volcanism.

  8. Effect of carbonic anhydrase on silicate weathering and carbonate formation at present day CO₂ concentrations compared to primordial values.

    PubMed

    Xiao, Leilei; Lian, Bin; Hao, Jianchao; Liu, Congqiang; Wang, Shijie

    2015-01-01

    It is widely recognized that carbonic anhydrase (CA) participates in silicate weathering and carbonate formation. Nevertheless, it is still not known if the magnitude of the effect produced by CA on surface rock evolution changes or not. In this work, CA gene expression from Bacillus mucilaginosus and the effects of recombination protein on wollastonite dissolution and carbonate formation under different conditions are explored. Real-time fluorescent quantitative PCR was used to explore the correlation between CA gene expression and sufficiency or deficiency in calcium and CO₂ concentration. The results show that the expression of CA genes is negatively correlated with both CO₂ concentration and ease of obtaining soluble calcium. A pure form of the protein of interest (CA) is obtained by cloning, heterologous expression, and purification. The results from tests of the recombination protein on wollastonite dissolution and carbonate formation at different levels of CO₂ concentration show that the magnitudes of the effects of CA and CO₂ concentration are negatively correlated. These results suggest that the effects of microbial CA in relation to silicate weathering and carbonate formation may have increased importance at the modern atmospheric CO₂ concentration compared to 3 billion years ago.

  9. [Marriage and fertility in present-day Japan: major findings of the Ninth Japanese National Fertility Survey].

    PubMed

    Atoh, M; Nakano, E; Otani, K; Kaneko, R

    1988-07-01

    Results of a major fertility survey conducted in Japan in June 1987 are presented, including data on age at first marriage, mate selection, arranged marriages, family types, wife's employment, fertility, birth timing, contraception, and abortion. (SUMMARY IN ENG)

  10. PRESENT-DAY GALACTIC EVOLUTION: LOW-METALLICITY, WARM, IONIZED GAS INFLOW ASSOCIATED WITH HIGH-VELOCITY CLOUD COMPLEX A

    SciTech Connect

    Barger, K. A.; Haffner, L. M.; Wakker, B. P.; Hill, Alex S.; Madsen, G. J.; Duncan, A. K. E-mail: haffner@astro.wisc.edu E-mail: wakker@astro.wisc.edu

    2012-12-20

    The high-velocity cloud Complex A is a probe of the physical conditions in the Galactic halo. The kinematics, morphology, distance, and metallicity of Complex A indicate that it represents new material that is accreting onto the Galaxy. We present Wisconsin H{alpha} Mapper kinematically resolved observations of Complex A over the velocity range of -250 to -50 km s{sup -1} in the local standard of rest reference frame. These observations include the first full H{alpha} intensity map of Complex A across (l, b) = (124 Degree-Sign , 18 Degree-Sign ) to (171 Degree-Sign , 53 Degree-Sign ) and deep targeted observations in H{alpha}, [S II] {lambda}6716, [N II] {lambda}6584, and [O I] {lambda}6300 toward regions with high H I column densities, background quasars, and stars. The H{alpha} data imply that the masses of neutral and ionized material in the cloud are similar, both being greater than 10{sup 6} M{sub Sun }. We find that the Bland-Hawthorn and Maloney model for the intensity of the ionizing radiation near the Milky Way is consistent with the known distance of the high-latitude part of Complex A and an assumed cloud geometry that puts the lower-latitude parts of the cloud at a distance of 7-8 kpc. This compatibility implies a 5% ionizing photon escape fraction from the Galactic disk. We also provide the nitrogen and sulfur upper abundance solutions for a series of temperatures, metallicities, and cloud configurations for purely photoionized gas; these solutions are consistent with the sub-solar abundances found by previous studies, especially for temperatures above 10{sup 4} K or for gas with a high fraction of singly ionized nitrogen and sulfur.

  11. Present-Day Hospital Readmissions after Left Ventricular Assist Device Implantation: A Large Single-Center Study.

    PubMed

    Hernandez, Ruben E; Singh, Steve K; Hoang, Dale T; Ali, Syed W; Elayda, MacArthur A; Mallidi, Hari R; Frazier, O H; Meyers, Deborah E

    2015-10-01

    Left ventricular assist device (LVAD) therapy improves survival, hemodynamic status, and end-organ perfusion in patients with refractory advanced heart failure. Hospital readmission is an important measure of the intensity of LVAD support care. We analyzed readmissions of 148 patients (mean age, 53.6 ± 12.7 yr; 83% male) who received a HeartMate II LVAD from April 2008 through June 2012. The patients had severe heart failure; 60.1% were in Interagency Registry for Mechanically Assisted Circulatory Support class 1 or 2. All patients were observed for at least 12 months, and readmissions were classified as planned or unplanned. Descriptive and multivariate regression analyses were used to identify predictors of unplanned readmission. Twenty-seven patients (18.2%) had no readmissions or 69 planned readmissions, and 121 patients (81.8%) had 460 unplanned readmissions. The LVAD-related readmissions were for bleeding, thrombosis, and anticoagulation (n=103; 49.1%), pump-related infections (n=60; 28.6%), and neurologic events (n=28; 13.3%). The readmission rate was 2.1 per patient-year. Unplanned readmissions were for comorbidities and underlying cardiac disease (54.3%) or LVAD-related causes (45.7%). In the unplanned-readmission rate, there was no significant difference between bridge-to-transplantation and destination-therapy patients. Unplanned readmissions were associated with diabetes mellitus (odds ratio [OR]=3.3; P=0.04) and with shorter mileage from residence to hospital (OR=0.998; P=0.046). Unplanned admissions for LVAD-related sequelae and ongoing comorbidities were common. Diabetes mellitus and shorter distance from residence to hospital were significant predictors of readmission. We project that improved management of comorbidities and of anticoagulation therapy will reduce unplanned readmissions of LVAD patients in the future.

  12. Neopositivism and the DSM psychiatric classification. An epistemological history. Part 2: Historical pathways, epistemological developments and present-day needs.

    PubMed

    Aragona, Massimiliano

    2013-12-01

    Little is known about the concrete historical sources for the use of neopositivist operational criteria by the DSM-III. This paper suggests that distinct sources operated implicitly. The current usefulness of the operational approach is questioned. It is shown that: (a) in epistemology, neopositivism has been replaced by more adequate accounts; (b) psychologists rejected operational definitions because these were unable to define the majority of mental phenomena; (c) mental symptoms cannot be directly described as such, because they already make part of the psychiatric diagnosis to which they belong. In conclusion, diagnosing is based on the hermeneutical co-construction of mental symptoms. The failure of the neopositivist programme suggests that it is time to reconcile scientific formalization and semiotic activity. PMID:24573752

  13. Valley Evolution and Controls on Present-Day Rock Slope Processes in the Matter and Saas Valleys, Switzerland

    NASA Astrophysics Data System (ADS)

    Leith, K.; Kos, A.; Löw, S.; Moore, J.

    2009-04-01

    Landforms in the Matter and Saas Valleys (Kanton Valais, Switzerland) indicate a progressive upstream transition from fluvially dominated to glacially dominated terrains. Large glaciers currently reside in the headwaters of both valleys, and the region was a major ice contributor to the Rhone Valley during the LGM. Characteristic geomorphic indicators linked to morphology, extent of glacial sediments and ice-rock contact surfaces, as well as river and terrace profiles within the two valleys suggest a parallel temporal evolution, despite variations in catchment size, lithology, and glacial input. Slope morphology and fan deposits indicate a concentration of high-energy rock slope activity (such as rock falls, topples, and slides) within a transitional geomorphic domain in the lower 1/3 of both valleys. This transitional domain is defined by a characteristic moderate gradient, linear, river profile. It separates a downstream detachment-limited fluvial domain from a transport-limited domain upstream, where a broad alluvial plain forms a thick infill in the relict glacial valley. Hillslope erosional processes appear considerably less developed and active in these neighboring domains. While the rock slope activity in the transitional domain initially seems to be a clear process response to renewed Holocene fluvial incision in the lower section of the valleys, mapping of glacial landforms indicates only limited incision may have taken place. Activity is concentrated on steep valley walls which extend up to 700m above the current valley floor. These are buttressed by significant talus deposits, which combined with the topography, mean there is likely to be little direct connection from the post-glacial fluvial activity to the erosional hillslope processes. Initial investigations suggest that a combination of repeated glacial erosion and debuttressing, as well as fluvial processes during interglacials may have lead to a significant, consistent differences in post-glacial stress redistribution in each domain. Large deviatoric stresses associated with high relief, and the removal of sedimentary buttresses in the transitional domain, may have induced fracturing of the rock mass through exfoliation and static fatigue, and conditioned rock slopes for ongoing failure.

  14. Lessons Learned and Present Day Challenges of Addressing 20th Century Radiation Legacies of Russia and the United States

    SciTech Connect

    KRISTOFZSKI, J.G.

    2000-10-26

    The decommissioning of nuclear submarines, disposal of highly-enriched uranium and weapons-grade plutonium, and processing of high-level radioactive wastes represent the most challenging issues facing the cleanup of 20th century radiation legacy wastes and facilities. The US and Russia are the two primary countries dealing with these challenges, because most of the world's fissile inventory is being processed and stored at multiple industrial sites and nuclear weapons production facilities in these countries.

  15. Relationships between pore pressure, stresses, and present-day geodynamics in the Scotian Shelf, offshore eastern Canada

    SciTech Connect

    Yassir, N.A.; Bell, J.S.

    1994-12-01

    A geomechanical study of the Mesozoic and Tertiary sediments beneath the Scotian Shelf shows that two major weak layers exist at depth: the over-pressured unit at 4000 m and the basal Argo salt, which is ductile and diapiric. A consistent relationships is observed between the overpressures and the stress state in the basin. First, the smaller horizontal principal stress increases dramatically just above the onset of overpressuring, and secondly, borehole breakouts, indicators of stress anisotropy-decrease in abundance within the overpressure zone. Neither tectonic shear nor rapid burial can explain these observations; however, overpressuring by fluid generation will result in horizontal stress increase and eventually lead to an isotropic stress state. Compelling evidence is found for hydrocarbon generation being a key cause of overpressuring in the Scotian Shelf.

  16. Effect of carbonic anhydrase on silicate weathering and carbonate formation at present day CO2 concentrations compared to primordial values

    NASA Astrophysics Data System (ADS)

    Xiao, Leilei; Lian, Bin; Hao, Jianchao; Liu, Congqiang; Wang, Shijie

    2015-01-01

    It is widely recognized that carbonic anhydrase (CA) participates in silicate weathering and carbonate formation. Nevertheless, it is still not known if the magnitude of the effect produced by CA on surface rock evolution changes or not. In this work, CA gene expression from Bacillus mucilaginosus and the effects of recombination protein on wollastonite dissolution and carbonate formation under different conditions are explored. Real-time fluorescent quantitative PCR was used to explore the correlation between CA gene expression and sufficiency or deficiency in calcium and CO2 concentration. The results show that the expression of CA genes is negatively correlated with both CO2 concentration and ease of obtaining soluble calcium. A pure form of the protein of interest (CA) is obtained by cloning, heterologous expression, and purification. The results from tests of the recombination protein on wollastonite dissolution and carbonate formation at different levels of CO2 concentration show that the magnitudes of the effects of CA and CO2 concentration are negatively correlated. These results suggest that the effects of microbial CA in relation to silicate weathering and carbonate formation may have increased importance at the modern atmospheric CO2 concentration compared to 3 billion years ago.

  17. Present-Day Hospital Readmissions after Left Ventricular Assist Device Implantation: A Large Single-Center Study.

    PubMed

    Hernandez, Ruben E; Singh, Steve K; Hoang, Dale T; Ali, Syed W; Elayda, MacArthur A; Mallidi, Hari R; Frazier, O H; Meyers, Deborah E

    2015-10-01

    Left ventricular assist device (LVAD) therapy improves survival, hemodynamic status, and end-organ perfusion in patients with refractory advanced heart failure. Hospital readmission is an important measure of the intensity of LVAD support care. We analyzed readmissions of 148 patients (mean age, 53.6 ± 12.7 yr; 83% male) who received a HeartMate II LVAD from April 2008 through June 2012. The patients had severe heart failure; 60.1% were in Interagency Registry for Mechanically Assisted Circulatory Support class 1 or 2. All patients were observed for at least 12 months, and readmissions were classified as planned or unplanned. Descriptive and multivariate regression analyses were used to identify predictors of unplanned readmission. Twenty-seven patients (18.2%) had no readmissions or 69 planned readmissions, and 121 patients (81.8%) had 460 unplanned readmissions. The LVAD-related readmissions were for bleeding, thrombosis, and anticoagulation (n=103; 49.1%), pump-related infections (n=60; 28.6%), and neurologic events (n=28; 13.3%). The readmission rate was 2.1 per patient-year. Unplanned readmissions were for comorbidities and underlying cardiac disease (54.3%) or LVAD-related causes (45.7%). In the unplanned-readmission rate, there was no significant difference between bridge-to-transplantation and destination-therapy patients. Unplanned readmissions were associated with diabetes mellitus (odds ratio [OR]=3.3; P=0.04) and with shorter mileage from residence to hospital (OR=0.998; P=0.046). Unplanned admissions for LVAD-related sequelae and ongoing comorbidities were common. Diabetes mellitus and shorter distance from residence to hospital were significant predictors of readmission. We project that improved management of comorbidities and of anticoagulation therapy will reduce unplanned readmissions of LVAD patients in the future. PMID:26504434

  18. Evidence and ideology as a rationale for light-therapy in Russia: from the Soviet Union to the present day

    PubMed Central

    Kühlbrandt, Charlotte; McKee, Martin

    2013-01-01

    Light therapy is still used to treat a number of common diseases in Russia. The practice is firmly anchored in history: Soviet clinical practice was divorced from the emerging field of evidence-based medicine. Medical researchers were cut off from international medical research and scientific literature, with much Soviet scientific activity based on a particular socialist ideology. In this study, the use of light therapy serves as a case study to explore tensions between international evidence-based medicine and practices developed in isolation under the Soviet Union, the legacy of which is to the detriment of many patients today. We used four different search methods to uncover scientific and grey literature, both historical and contemporary. We assessed the changing frequency of publications over time and contrasted the volume of literature on light therapy with more orthodox treatments such as statins and painkillers. Our search found an increasing number and comparatively large body of scientific publications on light therapy in the Russian language, and many publications emanating from prestigious Russian institutions. Combined with our analysis of the historical literature and our appraisal of 22 full text articles, this leads us to suggest that light therapy entered mainstream Soviet medical practice before the Stalinist period and still occupies an important position in contemporary Russian clinical practice. We propose that this outdated treatment survives in Russia in part due to the political, economic and social forces that helped to popularize it during Soviet times, and by the seeming justification offered by poorly executed studies. PMID:24040492

  19. Present-day Galactic Evolution: Low-metallicity, Warm, Ionized Gas Inflow Associated with High-velocity Cloud Complex A

    NASA Astrophysics Data System (ADS)

    Barger, K. A.; Haffner, L. M.; Wakker, B. P.; Hill, Alex. S.; Madsen, G. J.; Duncan, A. K.

    2012-12-01

    The high-velocity cloud Complex A is a probe of the physical conditions in the Galactic halo. The kinematics, morphology, distance, and metallicity of Complex A indicate that it represents new material that is accreting onto the Galaxy. We present Wisconsin Hα Mapper kinematically resolved observations of Complex A over the velocity range of -250 to -50 km s-1 in the local standard of rest reference frame. These observations include the first full Hα intensity map of Complex A across (\\mathit {l, b}) = (124{^\\circ }, 18{^\\circ }) to (171°, 53°) and deep targeted observations in Hα, [S II] λ6716, [N II] λ6584, and [O I] λ6300 toward regions with high H I column densities, background quasars, and stars. The Hα data imply that the masses of neutral and ionized material in the cloud are similar, both being greater than 106 M ⊙. We find that the Bland-Hawthorn & Maloney model for the intensity of the ionizing radiation near the Milky Way is consistent with the known distance of the high-latitude part of Complex A and an assumed cloud geometry that puts the lower-latitude parts of the cloud at a distance of 7-8 kpc. This compatibility implies a 5% ionizing photon escape fraction from the Galactic disk. We also provide the nitrogen and sulfur upper abundance solutions for a series of temperatures, metallicities, and cloud configurations for purely photoionized gas; these solutions are consistent with the sub-solar abundances found by previous studies, especially for temperatures above 104 K or for gas with a high fraction of singly ionized nitrogen and sulfur.

  20. Utilizing DNA analysis to combat the world wide plague of present day slavery--trafficking in persons.

    PubMed

    Palmbach, Timothy M; Blom, Jeffrey; Hoynes, Emily; Primorac, Dragan; Gaboury, Mario

    2014-02-01

    A study was conducted to determine if modern forensic DNA typing methods can be properly employed throughout the world with a final goal of increasing arrests, prosecutions, and convictions of perpetrators of modern day trafficking in persons while concurrently reducing the burden of victim testimony in legal proceedings. Without interruption of investigations, collection of samples containing DNA was conducted in a variety of settings. Evidentiary samples were analyzed on the ANDE Rapid DNA system. Many of the collected swabs yielded informative short tandem repeat profiles with Rapid DNA technology.

  1. Groups of Galaxies in the CDFS: Tracing the Evolution of Galaxies from z=1.6 to the Present Day

    NASA Astrophysics Data System (ADS)

    Mulchaey, John

    2012-10-01

    Although groups are the most common environment experienced by galaxies, we still know surprisingly little about the mechanisms that drive galaxy evolution in these systems. While galaxy-galaxy encounters and mergers are thought to be common in groups, recent observations and simulations suggest encounters with the hot intragroup medium may also be important. To help distinguish between these possibilities, groups with and without a hot intragroup medium must be studied over a range of redshifts. Such studies have been limited because groups tend to be very faint in X-rays and difficult to detect at even moderate redshifts. Fortunately, the recently completed 4 Msec Chandra observation of the CDFS now allows the hot intragroup gas to be detected in ordinary groups out to z=1 and beyond. Here, we propose to use archival HST images from GEMS, GOODS and CANDELS to study the galaxy populations in a unique sample of 40 X-ray groups and approximately 100 non-X-ray groups in the CDFS in the redshift range z=0.5 to z=1.6. The ACS and WFC3 images will be used to search for signs of interactions and disturbances in these galaxies which will allow a detailed analysis of the effects of interactions as a function of group mass and redshift. Since the depth of the Chandra exposure in the CDFS is unlikely to be matched for any other fields, our group sample will be the only one with sufficient X-ray data to allow such a study for the forseeable future.

  2. Stable lead isotope compositions in selected coals from around the world and implications for present day aerosol source tracing

    SciTech Connect

    M. Diaz-Somoano; M.E. Kylander; M.A. Lopez-Anton; I. Suarez-Ruiz; M.R. Martinez-Tarazona; M. Ferrat; B. Kober; D.J. Weiss

    2009-02-15

    The phasing out of leaded gasoline in many countries around the world at the end of the last millennium has resulted in a complex mixture of lead sources in the atmosphere. Recent studies suggest that coal combustion has become an important source of Pb in aerosols in urban and remote areas. Lead concentration and isotopic composition is reported for 59 coal samples representing major coal deposits worldwide in an attempt to characterize this potential source. The average concentration in these coals is 35 {mu}g Pb g{sup -1}, with the highest values in coals from Spain and Peru and the lowest in coals from Australia and North America. The {sup 206}Pb/{sup 207}Pb isotope ratios range between 1.15 and 1.24, with less radiogenic Pb in coals from Europe and Asia compared to South and North America. Comparing the Pb isotopic signatures of coals from this and previous studies with those published for Northern and Southern Hemisphere aerosols, we hypothesize that coal combustion might now be an important Pb source in China, the eastern U.S., and to some extent, in Europe but not as yet in other regions including South Africa, South America, and western U.S. This supports the notion that 'old Pb pollution' from leaded gasoline reemitted into the atmosphere or long-range transport (i.e., from China to the western U.S.) is important. Comparing the isotope ratios of the coals, the age of the deposits, and Pb isotope evolution models for the major geochemical reservoirs suggests that the lead isotope ratios (PbIC) in coals is strongly influenced by the depositional coal forming environment. 47 refs., 3 figs., 1 tab.

  3. Do MAGSAT anomalies contain a record of past and present-day mantle convection under South America?

    NASA Technical Reports Server (NTRS)

    Hastings, D. A.

    1985-01-01

    Global anomaly maps from the National Aeronautics and Space Administration's Magnetic Field Satellite (MAGSAT) have been spatially filtered to reduce the prominence of long-wavelength east-west bands and to improve the discrimination of anomalies within structural provinces. Previous research suggested a correlation between total-field MAGSAT anomaly lows in equatorial regions with crustal bodies of relatively high average magnetic susceptibility (such as Archaean shields), and of anomaly highs with bodies of low susceptibility (such as deep parts of basins). These correlations reverse at higher latitudes.

  4. Cervical cancer narratives: invoking 'God's will' to re-appropriate reproductive rights in present-day Romania.

    PubMed

    Pop, Cristina A

    2015-01-01

    Drawing from ethnographic fieldwork in contemporary Southern Romania, this paper scrutinises local moralities governing some women's refusal to enrol in free reproductive healthcare initiatives targeting cervical cancer through primary and secondary prevention (human papillomavirus [HPV] vaccination and Papanicolaou [Pap] testing, respectively). Women backed up their rejection of participation in official reproductive care programmes by mentioning 'God's will' as the ultimate trigger of cervical cancer. They withheld their own and their daughters' bodies from biomedical intervention and used discursive references to divine logic to imbue their refusal with moral legitimacy. However, 'God's will' is not a mere rhetorical device, since it has a correlate in many of these women's embodied reproductive experiences. As this paper argues, religious narratives, far from stripping ordinary citizens of their reproductive choices, constitute the medium through which they display individual agency. In fact, invoking 'God's will' empowers Romanian women to challenge state control and it enables them to re-appropriate their bodies by making a counter-intuitive, yet bold, choice.

  5. Present-day Surface Deformation and Vertical Motion In The Central Alborz (iran) From GPS and Absolute Gravity Measurements.

    NASA Astrophysics Data System (ADS)

    Masson, F.; Sedighi, M.; Hinderer, J.; Bayer, R.; Nilforoushan, F.; Luck, J.-M.; Vernant, P.; Chéry, J.

    The present tectonic of Iran results from the north-south convergence between Eura- sia and Arabia, with a rate of about 3 cm/year. The deformation of Iran is concen- trated in major belts along the south-western border (Zagros), the southern shore of the Caspian Sea (Alborz) and along the north-east border (Kopet-Dag). The Alborz range is an east-west mountain range which accommodates about 1 cm/year of short- ening between the Central Iranian Desert and the south Caspian Sea. The main tec- tonic structures are generally overthrusting range-parallel faults northward dipping in the south (North Tehran fault, Mosha fault) and southward dipping in the north (Amir fault, North Border fault). The compressive tectonic in the Alborz range is certainly accommodated by large vertical motions along the major faults. To study the defor- mation (horizontal and vertical movement) we have installed and measured a GPS network of 14 sites crossing the Alborz range east of Tehran. The GPS network is measured during campaigns performed each year. In order to well constrained the ver- tical deformation of the southern border of the Alborz, we have performed colocated GPS and absolute gravity measurements in 3 sites, one near the Mosha fault (Abali), one in the frontal thrust area of Tehran and one in the stable central Iranian block (Chesmeh-Sour). After two measures (2000 and 2001), some interesting preliminary results will be shown. The observed gravity variation for one year (Sept. 2000 - Sept. 2001) is -3.0 mgal +-2.6 mgal (Abali), -24.2 mgal +-4.8 mgal (Tehran) and +4.7 mgal +-2.3 mgal (Chesmeh-Sour). These results could be explained respectively by a tec- tonic uplift of about 10 mm/year in the Alborz, water pumping in the Tehran area and (unexplained) subsidence at Chesmeh-Sour. These results will be compared to the first estimation of the deformation obtained by GPS (horizontal repeatability < 3 mm and vertical repeatability < 5 mm).

  6. Utilizing DNA analysis to combat the world wide plague of present day slavery--trafficking in persons.

    PubMed

    Palmbach, Timothy M; Blom, Jeffrey; Hoynes, Emily; Primorac, Dragan; Gaboury, Mario

    2014-02-01

    A study was conducted to determine if modern forensic DNA typing methods can be properly employed throughout the world with a final goal of increasing arrests, prosecutions, and convictions of perpetrators of modern day trafficking in persons while concurrently reducing the burden of victim testimony in legal proceedings. Without interruption of investigations, collection of samples containing DNA was conducted in a variety of settings. Evidentiary samples were analyzed on the ANDE Rapid DNA system. Many of the collected swabs yielded informative short tandem repeat profiles with Rapid DNA technology. PMID:24577820

  7. Present-day and fossil rhodolith pavements compared: Their potential for analysing shallow-water carbonate deposits

    NASA Astrophysics Data System (ADS)

    Bassi, Davide; Nebelsick, James H.; Checconi, Alessio; Hohenegger, Johann; Iryu, Yasufumi

    2009-02-01

    Coralline red algae represent the main biogenic components in most shallow-water carbonate successions from the Eocene to the Recent. They contribute significantly to sediment production on open platforms. Carbonate sediments formed by unattached coralline algae include rhodolith pavements (RPs) which represent dense accumulations of rhodoliths, as well as maërl which is composed of rhodoliths, coralline algal branches and their detritus. Recent RPs sampled off Sesoko-jima (Okinawa-jima, southern Japan) occur at depths of 50-70 m on a submarine terrace. The taxonomic coralline composition is dominated by melobesioids associated with minor amounts of mastophoroids and sporolithaceans. The rhodoliths are characterised by various nuclei, an encrusting inner arrangement, encrusting to warty outer growth-forms and sub-spheroidal shapes. Bioerosion, encrustation and abrasion are the most prevalent taphonomic features. Possible fossil counterparts were identified in Chattian and Priabonian RPs from middle-ramp depositional systems from the Venetian area, north-east Italy. A direct comparison between Recent and fossil RPs is possible by contrasting the constituent rhodolith characteristics including taxonomic composition, nature of the nucleus, inner arrangement, outer growth-forms, size and shape as well as taphonomic signatures. This allows factors controlling rhodolith formation and growth in RPs to be compared especially with respect to hydrodynamic regimes and substrate type.

  8. Soil mapping and modelling for evaluation of the effects of historical and present-day soil erosion

    NASA Astrophysics Data System (ADS)

    Smetanova, Anna; Szwarczewski, Piotr

    2016-04-01

    The loess hilly lands in Danube Lowland are characterized by patchy soil-scape. The soil erosion processes uncover the subsurface, bright loess horizon, while non-eroded and colluvial soils are of the dark colour, in the chernozem area. With the modernisation of agriculture since the 1950's and in the process of collectivization, when small fields were merged into bigger, the soil degradation progressed. However, the analysis of historical sources and sediment archives showed the proofs of historical soil erosion. The objective of this study is to map the soil erosion patterns in connection of both pre- and post-collectivization landscape and to understand the accordingly developed soil erosion patterns. The combined methods of soil mapping and soil erosion modelling were applied in the part of the Trnavska pahorkatina Hilly Land in Danube Lowland. The detailed soil mapping in a zero-order catchment (0.28 km²) uncovered the removal of surface soil horizon of 0.6m or more, while the colluvial soils were about 1.1m deep. The soil properties and dating helped to describe the original soil profile in the valley bottom, and reconstruct the history of soil erosion in the catchment. The soil erosion model was applied using the reconstructed land use patterns in order to understand the effect of recent and historical soil erosion in the lowland landscape. This work was supported by the Slovak Research and Development Agency under the contract ESF-EC-0006-07 and APVV-0625-11; Anna Smetanová has received the support of the AgreenSkills fellowship (under grant agreement n°267196).

  9. Present-day regional climate simulation over Malaysia and western Maritime Continent region using PRECIS forced with ERA40 reanalysis

    NASA Astrophysics Data System (ADS)

    Kwan, Meng Sei; Tangang, Fredolin T.; Juneng, Liew

    2014-01-01

    This study examines the performance of the regional climate model, PRECIS, in reproducing the historical seasonal mean climatology over the Malaysian region. The performance of the model in simulating the seasonal climate pattern of the temperature, precipitation and large-scale circulation was reasonably good. The biases of temperature are less than 2 °C in general, while the seasonal cycles match the observed pattern despite some differences in certain regions. However, the biases for precipitation were greater, particularly over the mountainous areas. These biases could be associated with the deficiencies of the model physics, related to the misrepresentation of the land-surface interaction and convective scheme. Furthermore, the model fails to simulate the mean sea-level pressure over the interior part of Borneo with a significant low-pressure centre. A higher magnitude of the moisture convergence and divergence simulated by the model also contributed to the biases of precipitation over Malaysia.

  10. How fast is Arctic climate really changing? An insight from recent past, present day and near future coupled model simulations

    NASA Astrophysics Data System (ADS)

    Koenigk, Torben; Brodeau, Laurent

    2016-04-01

    Three quasi-equilibrium simulations using constant greenhouse gas forcing corresponding to years 2000, 2015 and 2030 have been performed with the global coupled model EC-Earth in order to analyze recent past and possible near future changes in the Arctic climate. The model simulations indicate an accelerated warming and ice extent reduction in the Arctic in near future conditions compared to the recent past. Both Arctic warming and sea ice reduction are closely linked to the increase of ocean heat transport into the Arctic, particularly through the Barents Sea Opening. Decadal variations of Arctic sea ice extent and ice volume are of the same order of magnitude as the observed ice extent reductions in the last 30 years and are dominated by the variability of the ocean heat transports through the Barents Sea Opening and the Bering Strait. Despite a general warming of mid and high northern latitudes, a substantial cooling is found in the subpolar gyre of the North Atlantic in the near future simulation. This cooling is related to a strong reduction in the AMOC, which is mainly caused by reduced deep water formation in the Labrador Sea. The observed trend towards a more negative phase of the North Atlantic Oscillation (NAO) and the observed linkage between autumn Arctic ice variations and NAO are reproduced in our model simulations for selected 30-year periods but are not robust over longer time periods. This indicates that the observed linkages between ice and NAO might not be robust in reality either, and that the observational time period is still too short to reliably separate the trend from the natural variability.

  11. Prevalence of NIDDM in Mexicans with paraphyletic and polyphyletic surnames.

    PubMed

    Garza-Chapa, Raul; De Los Angeles Rojas-Alvarado, Ma.; Cerda-Flores, Ricardo M.

    2000-11-01

    It has been hypothesized that the greater prevalence of non-insulin-dependent diabetes mellitus (NIDDM) in Mexicans may be related to their greater degree of Amerindian genetic admixture (AGA). The aim of this unmatched case-control study was to correlate the prevalence of NIDDM with AGA in 10 Mexican Mestizo populations non-randomly selected by surname. A sample of 1,699 unrelated persons, >44 years and residing in the state of Nuevo León, was selected on the basis of paraphyletic or polyphyletic surnames and interviewed in the Instituto Mexicano del Seguro Social (IMSS). All subjects received a medical examination, and diabetes was diagnosed on the basis of World Health Organization criteria. Three genetic marker systems were analyzed, and the percentage of AGA was calculated. Logistic regression analysis was performed with the prevalence as the dependent variable and sex and surname as the independent variables. The Spearman rank-order correlation analysis was calculated between the age-adjusted prevalence (45-75+ years) and AGA. The correlation revealed a pattern of increasing prevalence of NIDDM with increasing Amerindian ancestry by surname. Am. J. Hum. Biol. 12:721-728, 2000. Copyright 2000 Wiley-Liss, Inc. PMID:11534064

  12. Analysis of betaS and betaA genes in a Mexican population with African roots.

    PubMed

    Magaña, María Teresa; Ongay, Zoyla; Tagle, Juan; Bentura, Gilberto; Cobián, José G; Perea, F Javier; Casas-Castañeda, Maricela; Sánchez-López, Yoaly J; Ibarra, Bertha

    2002-01-01

    To investigate the origin of the beta(A) and beta(S) genes in a Mexican population with African roots and a high frequency of hemoglobin S, we analyzed 467 individuals (288 unrelated) from different towns in the states of Guerrero and Oaxaca in the Costa Chica region. The frequency of the sickle-cell trait was 12.8%, which may represent a public health problem. The frequencies of the beta-haplotypes were determined from 350 nonrelated chromosomes (313 beta(A) and 37 beta(S)). We observed 15 different beta(A) haplotypes, the most common of which were haplotypes 1 (48.9%), 2 (13.4%), and 3 (13.4%). The calculation of pairwise distributions and Nei's genetic distance analysis using 32 worldwide populations showed that the beta(A) genes are more closely related to those of Mexican Mestizos and North Africans. Bantu and Benin haplotypes and haplotype 9 were related to the beta(S) genes, with frequencies of 78.8, 18.2, and 3.0%, respectively. Comparison of these haplotypes with 17 other populations revealed a high similitude with the population of the Central African Republic. These data suggest distinct origins for the beta(A) and beta(S) genes in Mexican individuals from the Costa Chica region.

  13. Two Unique Glioma Subtypes Revealed.

    PubMed

    Poh, Alissa

    2016-04-01

    A comprehensive analysis of 1,122 diffuse glioma samples from The Cancer Genome Atlas has revealed two new subtypes of this common brain cancer, with molecular and clinical features that diverge from the norm. The study findings also support the use of DNA methylation profiles to improve glioma classification and treatment.

  14. Electrocardiograph abnormalities revealed during laparoscopy.

    PubMed

    Nijjer, Sukhjinder; Dubrey, Simon William

    2010-01-01

    This brief case presents a well patient in whom an electrocardiograph abnormality consistent with an accessory pathway was found during a routine procedure. We present the electrocardiographs, explain the underlying condition, and consider why the abnormality was revealed in this manner.

  15. Ancient DNA reveals key stages in the formation of Central European mitochondrial genetic diversity

    PubMed Central

    Brandt, Guido; Haak, Wolfgang; Adler, Christina J.; Roth, Christina; Szécsényi-Nagy, Anna; Karimnia, Sarah; Möller-Rieker, Sabine; Meller, Harald; Ganslmeier, Robert; Friederich, Susanne; Dresely, Veit; Nicklisch, Nicole; Pickrell, Joseph K.; Sirocko, Frank; Reich, David; Cooper, Alan; Alt, Kurt W.

    2014-01-01

    The processes which shaped modern European mitochondrial DNA (mtDNA) variation remain unclear. The initial peopling by Palaeolithic hunter-gatherers ~42kyrs ago and the immigration of Neolithic farmers into Europe ~8kyrs ago appear to have played important roles, but do not explain present-day mtDNA diversity. We generated mtDNA profiles of 364 individuals from prehistoric cultures in Central Europe to perform a chronological study, spanning the Early Neolithic to the Early Bronze Age (5,500–1,550 cal BC). We use this transect through time to identify four marked shifts in genetic composition during the Neolithic period, revealing a key role for Late Neolithic cultures in shaping modern Central European genetic diversity. PMID:24115443

  16. Creep Spatial and Temporal Evolution Revealed by InSAR Time Series Analysis

    NASA Astrophysics Data System (ADS)

    Jolivet, Romain; Lasserre, Cecile; Doin, Marie-Pierre; Peltzer, Gilles; Sun, Jianbao; Rong, Dailu; Shen, Zhengkang; Xu, Xiwei

    2013-01-01

    We characterize the present-day behaviour of the left-lateral Haiyuan fault system (Gansu, China), from InSAR data. The 260 km-long central segment of this fault is known as the "Tianzhu Seismic Gap" (Gaudemer et al. 1995), in between two segments that ruptured during the 1920 and 1927 earthquakes. Cavalié et al. (2008) has shown that shallow creep may occur near the junction between the "Tianzhu gap" and the 1920 rupture trace, from sparse ERS data stacking. We further investigate along-strike and temporal variations of strain accumulation across the Haiyuan fault. We first produce mean LOS velocity maps, revealing a variable creep-rate between 0 and 20 km and a constant slip-rate at depth (Jolivet et al. 2012). We then analyze temporal variations of the shallow creep distribution, and explore the relationships between the micro- and moderate seismic activity, the fault geometry and the surface creep rate.

  17. Complete mitochondrial genomes reveal neolithic expansion into Europe.

    PubMed

    Fu, Qiaomei; Rudan, Pavao; Pääbo, Svante; Krause, Johannes

    2012-01-01

    The Neolithic transition from hunting and gathering to farming and cattle breeding marks one of the most drastic cultural changes in European prehistory. Short stretches of ancient mitochondrial DNA (mtDNA) from skeletons of pre-Neolithic hunter-gatherers as well as early Neolithic farmers support the demic diffusion model where a migration of early farmers from the Near East and a replacement of pre-Neolithic hunter-gatherers are largely responsible for cultural innovation and changes in subsistence strategies during the Neolithic revolution in Europe. In order to test if a signal of population expansion is still present in modern European mitochondrial DNA, we analyzed a comprehensive dataset of 1,151 complete mtDNAs from present-day Europeans. Relying upon ancient DNA data from previous investigations, we identified mtDNA haplogroups that are typical for early farmers and hunter-gatherers, namely H and U respectively. Bayesian skyline coalescence estimates were then used on subsets of complete mtDNAs from modern populations to look for signals of past population expansions. Our analyses revealed a population expansion between 15,000 and 10,000 years before present (YBP) in mtDNAs typical for hunters and gatherers, with a decline between 10,000 and 5,000 YBP. These corresponded to an analogous population increase approximately 9,000 YBP for mtDNAs typical of early farmers. The observed changes over time suggest that the spread of agriculture in Europe involved the expansion of farming populations into Europe followed by the eventual assimilation of resident hunter-gatherers. Our data show that contemporary mtDNA datasets can be used to study ancient population history if only limited ancient genetic data is available.

  18. Archimedes: Accelerator Reveals Ancient Text

    SciTech Connect

    Bergmann, Uwe

    2004-02-24

    Archimedes (287-212 BC), who is famous for shouting 'Eureka' (I found it) is considered one of the most brilliant thinkers of all times. The 10th-century parchment document known as the 'Archimedes Palimpsest' is the unique source for two of the great Greek's treatises. Some of the writings, hidden under gold forgeries, have recently been revealed at the Stanford Synchrotron Radiation Laboratory at SLAC. An intense x-ray beam produced in a particle accelerator causes the iron in original ink, which has been partly erased and covered, to send out a fluorescence glow. A detector records the signal and a digital image showing the ancient writings is produced. Please join us in this fascinating journey of a 1,000-year-old parchment from its origin in the Mediterranean city of Constantinople to a particle accelerator in Menlo Park.

  19. Revealing ontological commitments by magic.

    PubMed

    Griffiths, Thomas L

    2015-03-01

    Considering the appeal of different magical transformations exposes some systematic asymmetries. For example, it is more interesting to transform a vase into a rose than a rose into a vase. An experiment in which people judged how interesting they found different magic tricks showed that these asymmetries reflect the direction a transformation moves in an ontological hierarchy: transformations in the direction of animacy and intelligence are favored over the opposite. A second and third experiment demonstrated that judgments of the plausibility of machines that perform the same transformations do not show the same asymmetries, but judgments of the interestingness of such machines do. A formal argument relates this sense of interestingness to evidence for an alternative to our current physical theory, with magic tricks being a particularly pure source of such evidence. These results suggest that people's intuitions about magic tricks can reveal the ontological commitments that underlie human cognition.

  20. Plan competitions reveal entrepreneurial talent

    SciTech Connect

    Madison, Alison L.

    2011-05-15

    Monthly economic diversity column for Tri-City Herald business section. Excerpt below: There’s something to be said for gaining valuable real-world experience in a structured, nurturing environment. Take for instance learning to scuba dive in the comfort of my resort pool rather than immediately hanging out with sharks while I figure out little things like oxygen tanks and avoiding underwater panic attacks. Likewise, graduate students are getting some excellent, supportive real-world training through university business plan competitions. These competitions are places where smart minds, new technologies, months of preparation and coaching, and some healthy pre-presentation jitters collide to reveal not only solid new business ideas, but also some promising entrepreneurial talent. In fact, professionals from around our region descend upon college campuses every spring to judge these events, which help to bridge the gap between academics and the real technology and business-driven economy.

  1. [Abdominal cystic tumor revealing lymphangioleiomyomatosis].

    PubMed

    Barbier, L; Ebbo, M; Andrac-Meyer, L; Schneilitz, N; Le Treut, Y-P; Reynaud-Gaubert, M; Hardwigsen, J

    2009-02-01

    We report the case of a 39 year-old woman with many years of intermittent abdominal pain who was found to have cystic masses evocative of cystic lymphangioma involving the posterior mediastinal and retroperitoneum. Worsening abdominal pain led to a recommendation for laparoscopic unroofing and decompression of the cysts. During the postoperative period, hemorrhagic shock required reintervention with excision of the tumoral mass. Pathologic examination revealed lymphangioleiomyomatosis (LAM). On the 15th postoperative day, the patient developed a chylopneumothorax which required prolonged chest tube drainage. The presence of multiple polycystic lesions in the pulmonary parenchyma supported the diagnosis of diffuse LAM with primary extrapulmonary presentation. This diagnosis should be considered preoperatively since it modifies the treatment: a complete excision of the cystic lesions seems to be necessary in order to prevent bleeding and lymphatic extravasation.

  2. Erosion and what it Reveals

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 20 November 2003

    This image is located near the boundary between Syrtis Major and Isidis Planitia. The top of the image shows rough material that has eroded away from the lower portion of the image, revealing an underlying surface that has many small craters. It also reveals an ancient flow lobe that is barely discernable, crossing the southern part of the image (this flow lobe is much easier to see as a smooth region in the context image).

    Image information: VIS instrument. Latitude 16.4, Longitude 77.9 East (282.1 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  3. Hubble Images Reveal Jupiter's Auroras

    NASA Technical Reports Server (NTRS)

    1996-01-01

    These images, taken by the Hubble Space Telescope, reveal changes in Jupiter's auroral emissions and how small auroral spots just outside the emission rings are linked to the planet's volcanic moon, Io. The images represent the most sensitive and sharply-detailed views ever taken of Jovian auroras.

    The top panel pinpoints the effects of emissions from Io, which is about the size of Earth's moon. The black-and-white image on the left, taken in visible light, shows how Io and Jupiter are linked by an invisible electrical current of charged particles called a 'flux tube.' The particles - ejected from Io (the bright spot on Jupiter's right) by volcanic eruptions - flow along Jupiter's magnetic field lines, which thread through Io, to the planet's north and south magnetic poles. This image also shows the belts of clouds surrounding Jupiter as well as the Great Red Spot.

    The black-and-white image on the right, taken in ultraviolet light about 15 minutes later, shows Jupiter's auroral emissions at the north and south poles. Just outside these emissions are the auroral spots. Called 'footprints,' the spots are created when the particles in Io's 'flux tube' reach Jupiter's upper atmosphere and interact with hydrogen gas, making it fluoresce. In this image, Io is not observable because it is faint in the ultraviolet.

    The two ultraviolet images at the bottom of the picture show how the auroral emissions change in brightness and structure as Jupiter rotates. These false-color images also reveal how the magnetic field is offset from Jupiter's spin axis by 10 to 15 degrees. In the right image, the north auroral emission is rising over the left limb; the south auroral oval is beginning to set. The image on the left, obtained on a different date, shows a full view of the north aurora, with a strong emission inside the main auroral oval.

    The images were taken by the telescope's Wide Field and Planetary Camera 2 between May 1994 and September 1995.

    This image and

  4. Satellites reveal Antarctic mass imbalance

    NASA Astrophysics Data System (ADS)

    Shepherd, A.

    2004-05-01

    Satellite radar observations have revealed a widespread mass imbalance in western Antarctica and rapid thinning of ice shelves at the Antarctic Peninsula. The former shows grounded ice retreat in a region previously considered unstable to such events, and the latter illuminates an ongoing debate as to the mechanism through which ice shelves have disintegrated over the past decade. Both measurements inform us as to the present state of balance of the cryosphere and its interactions with the southern oceans. Since 1992, the Amundsen Sea sector of the West Antarctic Ice Sheet has lost 39 cubic kilometers of its volume each year due to an imbalance between snow accumulation and ice discharge. A flow disturbance is responsible for removing the majority of that ice from the trunks of the Pine Island, Thwaites and Smith glacier drainage systems, raising global sea level by over 1 mm during the past decade alone. The coincidence of rapid ice thinning at the Amundsen Coast and warm circumpolar deep water intrusion in Pine Island Bay, coupled with a ~ 50 cubic kilometre annual freshening of the Ross Sea Gyre downstream, makes ocean melting an attractive proposition for the origin of the regional disturbance. At the same time, the Larsen Ice Shelf surface has lowered by up to 0.27 m per year, in tandem with a period of atmospheric warming and ice shelf collapse. The lowering cannot be explained by increased summer melt-water production alone, and must reflect a loss of basal ice through melting. Ocean temperature measurements close to the ice shelf barrier support this conclusion, making enhanced basal ice melting a likely factor linking the regional climate warming and the successive disintegration of sections of the Larsen Ice Shelf.

  5. Focus groups reveal consumer ambivalence.

    PubMed

    1983-01-01

    According to qualitative research, Salvadoreans are ambivalent about the use of contraceptives. Since complete responsibility for management of the CSM project was accepted by the Association Demografica Salvadorena (ADS), the agency which operates the contraceptive social marketing project in El Salvador, in November 1980, the need for decisions in such areas as product price increases, introduction of new condom brands, promotion of the vaginal foaming tablet, and assessment of product sales performance had arisen. The ICSMP funded market research, completed during 1983, was intended to provide the data on which such decisions by ADS could be based. The qualitative research involved 8 focus groups, comprised of men and women, aged 18-45, contraceptive users and nonusers, from the middle and lower socioeconomic strata of the city of San Salvador and other suburban areas. In each group a moderator led discussion of family planning and probed respondents for specific attitudes, knowledge, and behavior regarding the use of contraceptives. To assess attitudes at a more emotional level, moderators asked respondents to "draw" their ideas on certain issues. A marked discrepancy was revealed between respondents' intellectual responses to the issues raised in group discussion, as opposed to their feelings expressed in the drawings. Intellectually, participants responded very positively to family planning practice, but when they were asked to draw their perceptions, ambivalent feelings emerged. Drawings of both the user and the nonuser convey primarily negative aspects for either choice. The user is tense and moody toward her children; the nonuser loses her attractiveness and "dies." Figures also show drawings of some of the attitudes of single and married male participants. 1 drawing shows an incomplete and a complete circle, symbolizing a sterilized man (incomplete) and a nonsterilized man (complete). Another picture depicts a chained man who has lost his freedom

  6. High-precision Velocimetry Reveals δ Cephei's Secret Companion

    NASA Astrophysics Data System (ADS)

    Anderson, Richard I.; Sahlmann, Johannes; Holl, Berry; Eyer, Laurent

    2015-08-01

    The search for extra-solar planets has driven tremendous improvements in the precision of radial velocities measured with high-resolution echelle spectrographs. However, relatively few studies have as of yet exploited the present-day extreme (m/s) instrumental precision to study Cepheid variable stars.We have been observing the prototype of classical Cepheids, δ Cephei, since September 2011 using the HERMES spectrograph mounted to the Mercator telescope located at the Roque de los Muchachos Observatory on the island of La Palma. Being one of the most-studied variable stars, we originally chose δ Cephei as a maximum-precision reference for other Cepheids in our sample. To our great surprise however, we discovered a clear orbital signature in the homogeneous HERMES data. Adding in radial velocity data from the literature, we then determined δ Cephei's orbit (cf. Anderson et al. 2015, arXiv:1503.04116). The high orbital eccentricity (e=0.647) leads to close pericenter passages (rmin ~ 9.5 RδCep) which suggest an intriguing past that requires further study, since Cepheids are well-known magnifying glasses for stellar evolution (Kippenhahn & Weigert 1994). We furthermore determined a new parallax to δ Cephei (using Hipparcos data) that is in tension with previous estimates and shows that the orbit will have to be accounted for when measuring δ Cephei's parallax with Gaia.While some of our HERMES data are as precise as 9 m/s, we found correlated excess residuals when removing the reference pulsation model and orbital motion from the HERMES radial velocity data, leaving an RMS of 47 m/s. These higher-than-expected residuals are reminiscent of the "period-jitter" or "flickering" observed in high-precision photometry of Cepheids obtained with the Kepler and MOST satellites. This reveals a fortuitous synergy between variable stars studies and the field of exoplanet research and opens the window for a better understanding of Cepheid pulsations via high

  7. [Cholangitis revealing an intrahepatic Osler's disease].

    PubMed

    Asma, Kochlef; Dalila, Gargouri; Olfa, Bousnina; Malika, Romani; Afef, Kilani; Najet, BelHadg; Jamel, Kharrat; Abdeljabbar, Gorbel; Sarra, Shili; Chiraz, Jemli; Mohamed, Habib Daghfous; Slim, Khlifi; Anis, Ben Maamer; Abdelmajid, Letaïef

    2005-08-01

    Osler Weber Rendu Disease is an hereditary haemorrhagic télangectasia habitually revealed by reccurent bleeding (epistaxis). Hepatic involvement in Osler disease is found in 8 to 31%, manifested by cholestasis. We report an original observation of a cholangitis revealing Osler disease.

  8. REVEAL: Software Documentation and Platform Migration

    NASA Technical Reports Server (NTRS)

    Wilson, Michael A.; Veibell, Victoir T.; Freudinger, Lawrence C.

    2008-01-01

    The Research Environment for Vehicle Embedded Analysis on Linux (REVEAL) is reconfigurable data acquisition software designed for network-distributed test and measurement applications. In development since 2001, it has been successfully demonstrated in support of a number of actual missions within NASA s Suborbital Science Program. Improvements to software configuration control were needed to properly support both an ongoing transition to operational status and continued evolution of REVEAL capabilities. For this reason the project described in this report targets REVEAL software source documentation and deployment of the software on a small set of hardware platforms different from what is currently used in the baseline system implementation. This report specifically describes the actions taken over a ten week period by two undergraduate student interns and serves as a final report for that internship. The topics discussed include: the documentation of REVEAL source code; the migration of REVEAL to other platforms; and an end-to-end field test that successfully validates the efforts.

  9. Revealing advantage in a quantum network

    NASA Astrophysics Data System (ADS)

    Mukherjee, Kaushiki; Paul, Biswajit; Sarkar, Debasis

    2016-07-01

    The assumption of source independence was used to reveal nonlocal (apart from standard Bell-CHSH scenario) nature of correlations generated in entanglement swapping experiments. In this work, we have discussed the various utilities of this assumption to reveal nonlocality (via generation of nonbilocal correlations) and thereby exploiting quantumness under lesser requirements compared to some standard means of doing the same. We have also provided with a set of sufficient criteria, imposed on the states (produced by the sources) under which source independence can reveal nonbilocal nature of correlations in a quantum network.

  10. Titan's rotation reveals an internal ocean and changing zonal winds

    USGS Publications Warehouse

    Lorenz, R.D.; Stiles, B.W.; Kirk, R.L.; Allison, M.D.; Del Marmo, P.P.; Iess, L.; Lunine, J.I.; Ostro, S.J.; Hensley, S.

    2008-01-01

    Cassini radar observations of Saturn's moon Titan over several years show that its rotational period is changing and is different from its orbital period. The present-day rotation period difference from synchronous spin leads to a shift of ???0.36?? per year in apparent longitude and is consistent with seasonal exchange of angular momentum between the surface and Titan's dense superrotating atmosphere, but only if Titan's crust is decoupled from the core by an internal water ocean like that on Europa.

  11. Echinometra sea urchins acclimatized to elevated pCO2 at volcanic vents outperform those under present-day pCO2 conditions.

    PubMed

    Uthicke, Sven; Ebert, Thomas; Liddy, Michelle; Johansson, Charlotte; Fabricius, Katharina E; Lamare, Miles

    2016-07-01

    Rising atmospheric CO2 concentrations will significantly reduce ocean pH during the 21st century (ocean acidification, OA). This may hamper calcification in marine organisms such as corals and echinoderms, as shown in many laboratory-based experiments. Sea urchins are considered highly vulnerable to OA. We studied an Echinometra species on natural volcanic CO2 vents in Papua New Guinea, where they are CO2 -acclimatized and also subjected to secondary ecological changes from elevated CO2 . Near the vent site, the urchins experienced large daily variations in pH (>1 unit) and pCO2 (>2000 ppm) and average pH values (pHT 7.73) much below those expected under the most pessimistic future emission scenarios. Growth was measured over a 17-month period using tetracycline tagging of the calcareous feeding lanterns. Average-sized urchins grew more than twice as fast at the vent compared with those at an adjacent control site and assumed larger sizes at the vent compared to the control site and two other sites at another reef near-by. A small reduction in gonad weight was detected at the vents, but no differences in mortality, respiration, or degree of test calcification were detected between urchins from vent and control populations. Thus, urchins did not only persist but actually 'thrived' under extreme CO2 conditions. We suggest an ecological basis for this response: Increased algal productivity under increased pCO2 provided more food at the vent, resulting in higher growth rates. The wider implication of our observation is that laboratory studies on non-acclimatized specimens, which typically do not consider ecological changes, can lead to erroneous conclusions on responses to global change.

  12. Miocene to present-day shortening and intermontane basin formation in the Andean Puna Plateau, NW Argentina (24°30'S)

    NASA Astrophysics Data System (ADS)

    Strecker, M. R.; Bookhagen, B.; Alonso, R. N.; Pingel, H.; Freymark, J.

    2015-12-01

    With average elevations of about 3.7 km the Altiplano-Puna Plateau of the southern central Andes constitutes the world's second largest orogenic plateau. The plateau generally consists of internally drained, partly coalesced sedimentary basins bordered by reverse-fault bounded ranges, >5 km high. In the Puna, the Argentine sector of the plateau, active tectonism has been interpreted to be characterized by a low level of strike-slip and normal faulting associated with mafic volcanism. In contrast, the eastern plateau margins and the adjacent foreland record a higher level of seismicity and ongoing contraction. Despite ubiquitous Plio-Pleistocene normal faulting along the eastern plateau margins, our new observations record contraction in the plateau interior. Fanning of E-dipping Miocene sedimentary strata involved in the formation of an anticline in the Pocitos Basin of the central Puna interior indicates growth, which must have begun after 7 Ma; 1.5-m.y.-old lacustrine strata as well as tilted Pleistocene lacustrine shorelines associated with this structure indicate sustained uplift into the Quaternary. Corresponding observations along the eastern border of the Pocitos Basin show that <3.5-m.y.-old strata are involved in contractile deformation and basin compartmentalization. Shortening in the central Puna is compatible with Plio-Pleistocene shortening in the low-elevation Salar de Atacama farther west, and may indicate that low-elevation sectors of the plateau have not yet reached a critical elevation that is conducive to normal faulting as observed elsewhere. The onset of extensional deformation in the Puna is thus highly disparate in space and time. Coeval regional thrusting, strike-slip, and normal faulting do not support a structural and topographic setting that promotes wholesale extension and orogenic collapse of the plateau realm.

  13. The evolution of paediatrics from archaeological times to the mid-nineteenth century and the historical influence on present day practice.

    PubMed

    Rangroo, Vinita

    2008-05-01

    The history of childcare dates back to the beginning of time. This article critically analyses the history of paediatrics from its roots to mid-nineteenth century with the view to examine its evolution and influence on today's practice. Paediatrics as a sub-speciality of medicine only began in the fifteenth century when the Four Incunabula were published in the West. This was the first attempt at producing a comprehensive and accessible reference paediatric text. However, long before the Incunabula, early traces of childcare are found in different cultures like Egyptian, Indian and Chinese. Modern paediatrics is a highly advanced field of medicine that relies on many recent technological innovations. In spite of these, this paper concludes that paediatrics today is very much based on concepts, such as observation and clinical skills, introduced many centuries ago. The basic approach used in everyday clinical practice owes more to century-old ideas of scientists. PMID:18394119

  14. The evolution of paediatrics from archaeological times to the mid-nineteenth century and the historical influence on present day practice.

    PubMed

    Rangroo, Vinita

    2008-05-01

    The history of childcare dates back to the beginning of time. This article critically analyses the history of paediatrics from its roots to mid-nineteenth century with the view to examine its evolution and influence on today's practice. Paediatrics as a sub-speciality of medicine only began in the fifteenth century when the Four Incunabula were published in the West. This was the first attempt at producing a comprehensive and accessible reference paediatric text. However, long before the Incunabula, early traces of childcare are found in different cultures like Egyptian, Indian and Chinese. Modern paediatrics is a highly advanced field of medicine that relies on many recent technological innovations. In spite of these, this paper concludes that paediatrics today is very much based on concepts, such as observation and clinical skills, introduced many centuries ago. The basic approach used in everyday clinical practice owes more to century-old ideas of scientists.

  15. Shear failure of icy satellites: Present-day implications along Enceladus's Tiger Stripes and indications of past strike-slip faulting on Ganymede's Dardanus Sulcus

    NASA Astrophysics Data System (ADS)

    Cameron, M. E.; Smith-Konter, B. R.; Pappalardo, R. T.

    2012-12-01

    The icy fractured surfaces of both Enceladus and Ganymede offer many candidate faults for studying both past and potentially present tectonic activity. Recent studies have suggested that Enceladus's "tiger stripe" fractures may be associated with tectonic strike-slip (shear) motions as a result of Coulomb failure, but low coefficients of friction were primarily considered in past stress models. Recent work suggests that friction is highly sensitive to the state of seismic fault slip; low friction (μf = 0.1-0.2) may be applicable in initial slip events and high friction (μf = 0.3-0.6) may be more appropriate for subsequent sliding velocities. On Ganymede, strike-slip tectonics is common, notably where a prominent fault offsets Dardanus Sulcus. We investigate the role of fault friction and orbital eccentricity in the development of Enceladus's tiger stripes and Ganymede's Dardanus Sulcus. We consider both tidal diurnal and non-synchronous rotation (NSR) stresses, as applicable, and compute Coulomb failure conditions for these target fractures. For the Enceladus tiger stripes, previous shear failure models showed that low coefficients of friction (μf = 0.1-0.2) and shallow fracture depths (2-4 km) provide a very active diurnal shear failure scenario. Our new simulations suggest that shear failure is also possible for friction coefficients as high as uf = 0.6 at depths of 2 km, but the lateral extent of failure is suppressed in comparison. For Ganymede's Dardanus Sulcus, we consider tidal stress scenarios for both present (0.0013) and possible past high (~0.05) eccentricity. We find that NSR shear stress resolved along the Dardanus fault is sufficient to induce failure to ~1.4 km depths for μf ~0.3. For past high eccentricity, diurnal stress would have modulated NSR stress by ~100 kPa through Ganymede's tidal cycle, which could have also induced shear heating and tidal walking mechanisms. Together, these tidally driven failure models for Enceladus and Ganymede are providing key insights into the frictional and orbital constraints of strike-slip fault systems on outer planet satellites.

  16. Late Glacial to Holocene environments in the present-day coldest region of the Northern Hemisphere inferred from a pollen record of Lake Billyakh, Verkhoyansk Mts, NE Siberia

    NASA Astrophysics Data System (ADS)

    Müller, S.; Tarasov, P. E.; Andreev, A. A.; Diekmann, B.

    2009-03-01

    In this study, a radiocarbon-dated pollen record from Lake Billyakh (65°17' N, 126°47' E; 340 m a.s.l.) in the Verkhoyansk Mountains was used to reconstruct vegetation and climate change since about 15 kyr BP. The pollen record and pollen-based biome reconstruction suggest that open cool steppe (STEP) and grass and sedge tundra (TUND) communities with Poaceae, Cyperaceae, Artemisia, Chenopodiaceae, Caryophyllaceae and Selaginella rupestris dominated the area from 15 to 13.5 kyr BP. On the other hand, the constant presence of Larix pollen in quantities comparable to today's values points to the constant presence of boreal deciduous conifer (CLDE) trees in the regional vegetation during the Late Glacial. A major spread of shrub tundra communities, including birch (Betula sect. Nanae), alder (Duschekia fruticosa) and willow (Salix) species, is dated to 13.5-12.7 kyr BP, indicating a noticeable increase in precipitation toward the end of the Last Glaciation, particularly during the Bølling-Allerød Interstadial. Between 12.7 and 11.4 kyr BP pollen percentages of herbaceous taxa rapidly increased, whereas shrub taxa percentages decreased, suggesting strengthening of the steppe communities associated with the relatively cold and dry Younger Dryas Stadial. However, the pollen data in hand indicate that Younger Dryas climate was less severe than the climate during the earlier interval from 15 to 13.5 kyr BP. The onset of the Holocene is marked in the pollen record by the highest values of shrub and lowest values of herbaceous taxa, suggesting a return of warmer and wetter conditions after 11.4 kyr BP. Percentages of tree taxa increase gradually and reach maximum values after 7 kyr BP, reflecting the spread of boreal cold deciduous and taiga forests in the region. An interval between 7 and 2 kyr BP is noticeable for the highest percentages of Scots pine (Pinus subgen. Diploxylon), spruce (Picea) and fir (Abies) pollen, indicating mid-Holocene spread of boreal forest communities in response to climate amelioration and degradation of the permafrost layer.

  17. Late Glacial to Holocene environments in the present-day coldest region of the Northern Hemisphere inferred from a pollen record of Lake Billyakh, Verkhoyansk Mts, NE Siberia

    NASA Astrophysics Data System (ADS)

    Müller, S.; Tarasov, P. E.; Andreev, A. A.; Diekmann, B.

    2008-11-01

    In this study a radiocarbon-dated pollen record from Lake Billyakh (65°17'N, 126°47'E; 340 m a.s.l.) in the Verkhoyansk Mountains was used to reconstruct vegetation and climate change since about 15 kyr BP (1 kyr=1000 cal. yr). The pollen record and pollen-based biome reconstruction suggest that open cool steppe and grass and sedge tundra communities with Poaceae, Cyperaceae, Artemisia, Chenopodiaceae, Caryophyllaceae and Selaginella rupestris dominated the area from 15 to 13.5 kyr BP. On the other hand, the constant presence of Larix pollen in quantities comparable to today's values points to the constant presence of boreal deciduous conifer trees in the regional vegetation during the last glaciation. A major spread of shrub tundra communities, including birch (Betula sect. Nanae), alder (Duschekia fruticosa) and willow (Salix) species, is dated to 13.5 12.7 kyr BP, indicating a noticeable increase in precipitation toward the end of the last glaciation, particularly during the Allerød Interstadial. Between 12.7 and 11.4 kyr BP pollen percentages of herbaceous taxa rapidly increased, whereas shrub taxa percentages decreased, suggesting strengthening of the steppe communities associated with the relatively cold and dry Younger Dryas Stadial. However, the pollen data in hand indicate that Younger Dryas climate was less severe than the climate during the earlier interval from 15 to 13.5 kyr BP. The onset of the Holocene is marked in the pollen record by the highest values of shrub and lowest values of herbaceous taxa, suggesting a return of warmer and wetter conditions after 11.4 kyr BP. Percentages of tree taxa increase gradually and reach maximum values after 7 kyr BP, reflecting the spread of boreal cold deciduous and taiga forests in the region. An interval between 7 and 2 kyr BP is noticeable for the highest percentages of Scots pine (Pinus subgen. Diploxylon), spruce (Picea) and fir (Abies) pollen, indicating mid-Holocene spread of boreal forest communities in response to climate amelioration and degradation of the permafrost layer.

  18. [The different present-day clinical picture of human African trypanosomiasis caused by T. b. gambiense. Analysis of 300 cases from a focus in Daloa, Ivory Coast].

    PubMed

    Boa, Y F; Traore, M A; Doua, F; Kouassi-Traore, M T; Kouassi, B E; Giordano, C

    1988-01-01

    300 patients with sleeping sickness have been admitted, at the AHT clinic of Daloa, over a time period of 22 months. The sex ratio of the patients is 1.5 males for 1 female; the mean age is 25.5 years. The most frequent signs and symptoms observed by clinical examination are: fever (30%), nodes (86.3%), prurigo (43.3%), splenomegaly (15.3%), hepatomegaly (1%), headache (72.6%), vigilance and sleeping disturbances (68.7%), perioral reflexes (67.6%), cheiro-oral reflexes (64.3%), movement disorders consisting of tremor, choreo-athetosis movements, buccal dyskinesia or seizures (35%), motor palsy and gait disorders (15%), tonus disturbances (12.3%), sensitivity abnormalities (17%), endocrine disorders (16.3%), psychiatric symptoms (6.3%). According to CSF status, 261 patients have been classified in second period (P2). This group, although biologically well defined, is in fact a miscellaneous group of clinical signs and symptoms ranging from apparently normal patients to sleeping comatose and cachectic patients. 93% of the patients in this group have peripheral signs associated with neurological symptoms. They are as frequent in the first period as in the second period, with a statistical significance. This is an argument to think that the CNS is early affected in the course of the disease. The classification of the patients in groups of increasing neurological impairments, is in accordance with this hypothesis. 89% of the patients in the second period have only slight neurological signs. This explain how difficult it is for a physician to use melarsoprol in the treatment of all patients classified in second period.

  19. The Formation of Liquid Water on Present-Day Mars: Calcium-Magnesium Chloride Brines in the Antarctic Dry Valleys as a Mars Analog

    NASA Astrophysics Data System (ADS)

    Toner, J. D.; Catling, D. C.

    2016-09-01

    By analogy to the Antarctic Dry Valleys, Ca-Mg-Cl brines may be responsible for aqueous flows on Mars. We use modeling to show that Ca-Mg-Cl brines could be stable on Mars, and are often more favorable for forming solutions than perchlorate salts.

  20. Control of hyper-extended passive margin architecture on subduction initiation with application to the Alps and present-day North Atlantic ocean

    NASA Astrophysics Data System (ADS)

    Candioti, Lorenzo; Bauville, Arthur; Picazo, Suzanne; Mohn, Geoffroy; Kaus, Boris

    2016-04-01

    Hyper-extended magma-poor margins are characterized by extremely thinned crust and partially serpentinized mantle exhumation. As this can act as a zone of weakness during a subsequent compression event, a hyper-extended margin can thus potentially facilitate subduction initiation. Hyper-extended margins are also found today as passive margins fringing the Atlantic and North Atlantic ocean, e.g. Iberia and New Foundland margins [1] and Porcupine, Rockwall and Hatton basins. It has been proposed in the literature that hyper-extension in the Alpine Tethys does not exceed ~600 km in width [2]. The geodynamical evolution of the Alpine and Atlantic passive margins are distinct: no subduction is yet initiated in the North Atlantic, whereas the Alpine Tethys basin has undergone subduction. Here, we investigate the control of the presence of a hyper-extended margin on subduction initiation. We perform high resolution 2D simulations considering realistic rheologies and temperature profiles for these locations. We systematically vary the length and thickness of the hyper-extended crust and serpentinized mantle, to better understand the conditions for subduction initiation. References: [1] G. Manatschal. New models for evolution of magma-poor rifted margins based on a review of data and concepts from West Iberia and the Alps. Int J Earth Sci (Geol Rundsch) (2004); 432-466. [2] G. Mohn, G. Manatschal, M. Beltrando, I. Haupert. The role of rift-inherited hyper-extension in alpine-type orogens. Terra Nova (2014); 347-353.

  1. Discovery of Seafloor Massive Sulfides in an Andesite-Dacite Knoll Caldera off Present-Day Volcanic Front, Izu-Ogasawara Island Arc, Japan

    NASA Astrophysics Data System (ADS)

    Iizasa, K.; Asada, A.; Lee, S.; Mizuno, K.; Katase, F.; Kojima, M.; Kurozawa, T.

    2015-12-01

    We report the discovery of sulfide mounds with 20 to 30 m high sulfide chimneys in the Higashi-Aogashima hydrothermal field of a Quaternary andesite-dacite knoll caldera at the frontal arc side off Quaternary volcanic front, Izu-Ogasawara island arc, Japan. The discovery was carried out based on the systematic survey method of geological technique and a developed acoustic device using AUV. The knoll caldera 12 km east of Aogashima volcanic island is the size 10 km to 9 km of its rim and 820 m deep at its deepest caldera floor. According to the results of heavy mineral analysis for caldera sediments by a gravity corer, at least two areas were inferred to sites of potential hydrothermal activity associated with seafloor massive sulfides. After the precise acoustic survey using AUV there are many mound-like structures in the both inferred areas on the floor. Two major hydrothermal fields among them so far, which are a conical sulfide mound on the southeast flank of the central cone and a ridge-like mound on the inferred caldera boundary fault in the southeast, were confirmed based on sulfide samples recovered by a gravity corer during the next survey stage. One of them occurs at the water depth of 760 m to 770 m. It has active sulfide chimneys (ca. 20 m high) on the conical sulfide mound of about 40 m in diameter with 20 m high. Samples from the mound are composed of major sphalerite with moderate galena and barite, and minor chalcopyrite and pyrite. Another mound associated with chimneys at the water depth ranging from 740m to 770m on the southeast caldera boundary fault forms a small, east-west trend ridge-like shape. The ridge sizes more than 100 m long with 10 m wide. Chimneys are more than 30 m high. It is inferred that the mound is composed of major sphalerite and moderate barite based on samples cored at the margin of the mound. These results indicate that more than several sulfide mounds would be confirmed in the caldera floor by ROV surveys this September.

  2. Higher Education as a Means of Upward Social Mobility: The Expectations of Graduates and the Realities of Present-Day Society

    ERIC Educational Resources Information Center

    Burlutskaia, M. G.

    2014-01-01

    Research data show that higher education in Russia is less of a vehicle of upward mobility than it was in earlier times, not least because it is becoming less of an advantage as the percentage of people with degrees increases. This raises questions about what the goals of higher education should be, and of how to prepare young people for the job…

  3. Spatial Correlation of Deep Moonquakes and Mare Basalts and Implications for Lunar Present-day Mantle Structure, Magmatism and Thermal Evolution

    NASA Astrophysics Data System (ADS)

    Muirhead, A. C.; Zhong, S.

    2010-12-01

    In order to understand the evolution and interior dynamics of the Moon, it is necessary to understand the petrogenesis of the mare basalts which dominate the nearside surface. Samples and observations from the Apollo program have helped put constraints on the composition and the geological processes of the mare basalts. Geochemical and petrological studies of lunar samples suggest that this magmatism must have originated from a heterogeneous mantle and were mostly emplaced between 3.85 and 3.0 billion years ago although the depth of the source regions of the mare basalts is poorly constrained by petrological experiments with estimated depths ranging from 100 to 500 km [Shearer et al, 2006]. This leads to different hypotheses with shallow and deep physical processes for mare basalt genesis [Zhong et al, 2000 and Wieczorek and Phillips, 2000]. Another important first order observation from the Apollo era is the presence of moonquakes recorded by the Apollo Seismic Network. Significant work has been done to locate the hypocenters of the moonquakes, especially those deemed deep moonquake clusters [e.g., Nakamura, 1982]. The deep moonquakes (DMQs) were found to occur at depths of 700-900 km in about 300 clusters or “nests” mostly on the nearside [Nakamura 2003, 2005]. Understanding the location and cause of the DMQ will help constrain the current state of the mantle, including the presence of heterogeneties. While it remains unresolved whether the nearside distribution of DMQs is due to biasing effects of the nearside distribution of Apollo seismic stations, it has been suggested that most of the DMQ nests tend to occur near mare basalt terrains [Minshull and Goult, 1988]. In this study, we have correlated the presence of mare basalts with the epicenters of ~100 deep moonquake clusters, using recent remote sensing data of FeO as a proxy for mare basalts [e.g.,Lawrence et al, 2000] and newly compiled locations of DMQs clusters [Nakamura, 2005]. Our results show that as many as 86% of the DMQs are within 5 degrees of mare basalts with FeO concentrations greater than 9%. Our analysis also rejects the random distribution of DMQs with regard to mare basalts. Given the lack of mare basalts on the farside, save some large craters, and the clear correlation between the basalts and DMQs it might be possible that DMQs are predominantly nearside features and closely related to the mare basalts. If this relationship is correct, then the origin of the mare basalts might be much deeper than previously thought in order to correlate with the known depths of the deep moonquakes.

  4. Observations and modeling of northern mid-latitude recurring slope lineae (RSL) suggest recharge by a present-day martian briny aquifer

    NASA Astrophysics Data System (ADS)

    Stillman, David E.; Michaels, Timothy I.; Grimm, Robert E.; Hanley, Jennifer

    2016-02-01

    Recurring slope lineae (RSL) are narrow (0.5-5 m) dark features on Mars that incrementally lengthen down steep slopes, fade in colder seasons, and recur annually. These features have been identified from the northern to southern mid-latitudes. Here, we describe how observations of northern mid-latitude RSL in northern Chryse Planitia and southwestern Acidalia Planitia (CAP) suggest that brines start flowing before northern spring equinox and continue for more than half a Mars-year (490 ± 40 sols, spanning solar longitude 337° ± 11°-224° ± 20°). All CAP RSL are found on the steep slopes of craters and their source zones are at or below the elevation of the surrounding plains. Spacecraft-derived surface temperature observations cannot resolve individual RSL, so thermal modeling was used to determine that CAP RSL have a freezing temperature of 238-252 K, freeze and melt diurnally, and flow only occurs within the top ∼8 cm of the regolith. Furthermore, we calculate that a typical CAP RSL has a water budget of 1.5-5.6 m3/m of headwall. Therefore, such a large water budget makes annual recharge via atmospheric or subsurface diffusion sources unlikely. Alternatively, we hypothesize that the most plausible RSL source is a briny aquifer with a freezing temperature less than or equal to the mean annual CAP surface temperature (220-225 K). The annual cycle is as follows: in late autumn, the shallowest part of the brine feeding the source zone freezes, forming an ice dam. As spring approaches, temperatures rise and the dam is breached. Brine is discharged and the RSL initially lengthens rapidly (>1.86 m/sol), the lengthening rate then slows considerably, to ∼0.25 m/sol. Eventually, the losses equal the discharge rate and the RSL reaches its equilibrium phase. As brine flows in the RSL some of the water is lost to the atmosphere, therefore the freezing temperature of the brine within the RSL is higher (238-252 K) as the brine transitions to a super-eutectic salt concentration. In the late autumn, falling temperatures restore the ice dam and the H2O in the RSL slowly sublimates away. Overall, CAP RSL possess a significantly different seasonality and much longer duration than typical southern mid-latitude RSL, suggesting that RSL at different latitude bands have different source types. Lastly, CAP RSL are the best evidence that shallow groundwater may still exist on Mars.

  5. Partitioning of oblique convergence in the Northern Andes subduction zone: Migration history and the present-day boundary of the North Andean Sliver in Ecuador

    NASA Astrophysics Data System (ADS)

    Alvarado, A.; Audin, L.; Nocquet, J. M.; Jaillard, E.; Mothes, P.; Jarrín, P.; Segovia, M.; Rolandone, F.; Cisneros, D.

    2016-05-01

    Along the Ecuadorian margin, oblique subduction induces deformation of the overriding continental plate. For the last 15 Ma, both exhumation and tectonic history of Ecuador suggest that the northeastward motion of the North Andean Sliver (NAS) was accompanied by an eastward migration of its eastern boundary and successive progressively narrowing restraining bends. Here we present geologic data, earthquake epicenters, focal mechanisms, GPS results, and a revised active fault map consistent with this new kinematic model. All data sets concur to demonstrate that active continental deformation is presently localized along a single major fault system, connecting fault segments from the Gulf of Guayaquil to the eastern Andean Cordillera. Although secondary faults are recognized within the Cordillera, they accommodate a negligible fraction of relative motion compared to the main fault system. The eastern limit is then concentrated rather than distributed as first proposed, marking a sharp boundary between the NAS, the Inca sliver, and the Subandean domain overthrusting the South American craton. The NAS limit follows a northeast striking right-lateral transpressional strike-slip system from the Gulf of Guayaquil (Isla Puná) to the Andean Cordillera and with the north-south striking transpressive faults along the eastern Andes. Eastward migration of the restraining belt since the Pliocene, abandonment of the sutures and reactivation of north-south striking ancient fault zones lead to the final development of a major tectonic boundary south and east of the NAS, favoring its extrusion as a continental sliver, accommodating the oblique convergence of the Nazca oceanic plate toward South America.

  6. Dendritic spines and development: towards a unifying model of spinogenesis--a present day review of Cajal's histological slides and drawings.

    PubMed

    García-López, Pablo; García-Marín, Virginia; Freire, Miguel

    2010-01-01

    Dendritic spines receive the majority of excitatory connections in the central nervous system, and, thus, they are key structures in the regulation of neural activity. Hence, the cellular and molecular mechanisms underlying their generation and plasticity, both during development and in adulthood, are a matter of fundamental and practical interest. Indeed, a better understanding of these mechanisms should provide clues to the development of novel clinical therapies. Here, we present original results obtained from high-quality images of Cajal's histological preparations, stored at the Cajal Museum (Instituto Cajal, CSIC), obtained using extended focus imaging, three-dimensional reconstruction, and rendering. Based on the data available in the literature regarding the formation of dendritic spines during development and our results, we propose a unifying model for dendritic spine development.

  7. [Association of the strA-strB genes with plasmids and transposons in the present-day bacteria and in bacterial strains from permafrost].

    PubMed

    Petrova, M A; Gorlenko, Zh M; Soina, V S; Mindlin, S Z

    2008-09-01

    Transposons closely related to the streptomycin resistance transposon of modem bacteria, Tn5393, were detected in the bacterial isolates from permafrost resistant to streptomycin. Many transposons studied were located on the medium-size plasmids with a narrow host range. None of the streptomycin-resistant strains isolated from permafrost contained small plasmids carrying the strA-strB genes and related to the broad host range plasmid RSF1010.

  8. The Danger of Not Facing History: Exploring the Link between Education about the Past and Present-Day Anti-Semitism and Racism in Hungary

    ERIC Educational Resources Information Center

    van Iterson, Swaan; Nenadovic, Maja

    2013-01-01

    Until a few years ago the international media devoted scant attention to Hungary. Recently, however, multiple news reports and analyses have expressed concern about rising racism and extremism in this country, as well as a sense that the country's democracy is unraveling. It has often been argued that economic hardship is an important contributor…