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1

Emergência e vigor de plântulas de Cedrela fissilis L. em função de diferentes posições de profundidades de semeadura  

Microsoft Academic Search

Emergence and vigor of Cedrela fissilis L. seedlings in function of the sowing position and depth. Cedrela fissilis L. are Meliaceae, popularly known as cedro. This species is native to Brazil, and owing to its qualities for the timber industry, it is being exploited progressively at its place of occurrence until the point of exhaustion. It is now listed as

Sueli da Silva Santos; Mácio Farias de Moura; Roberta Sales Guedes; Edilma Pereira Gonçalves; Edna Ursulino; Paulo Alexandre; Fernandes Rodrigues de Melo

2009-01-01

2

Effect of latitudinal gradient and impact of logging on genetic diversity of Cedrela lilloi along the Argentine Yungas Rainforest  

PubMed Central

Cedrela lilloi C. DC. (cedro coya, Meliaceae), an important south American timber species, has been historically overexploited through selective logging in Argentine Yungas Rainforest. Management and conservation programs of the species require knowledge of its genetic variation patterns; however, no information is available. Molecular genetic variability of the species was characterized to identify high-priority populations for conservation and domestication purposes. Fourteen native populations (160 individuals) along a latitudinal gradient and with different logging's intensities were assessed by 293 polymorphic AFLP (amplified fragment length polymorphism) markers. Genetic diversity was low (Ht = 0.135), according to marginal location of the species in Argentina. Most of the diversity was distributed within populations (87%). Northern populations showed significant higher genetic diversity (R2= 0.69) that agreed with latitudinal pattern of distribution of taxonomic diversity in the Yungas. Three clusters were identified by Bayesian analysis in correspondence with northern, central, and southern Yungas. An analysis of molecular variance (AMOVA) revealed significant genetic differences among latitudinal clusters even when logging (?RT = 0.07) and unlogging populations (?PT = 0.10) were separately analyzed. Loss of genetic diversity with increasing logging intensity was observed between neighboring populations with different disturbance (?PT = 0.03–0.10). Bottlenecks in disturbed populations are suggested as the main cause. Our results emphasize both: the necessity of maintaining the genetic diversity in protected areas that appear as possible long-term refuges of the species; and to rescue for the national system of protected areas some high genetic diversity populations that are on private fields.

Inza, Maria V; Zelener, Noga; Fornes, Luis; Gallo, Leonardo A

2012-01-01

3

Niche evolution through time and across continents: The story of Neotropical Cedrela (Meliaceae).  

PubMed

• Premise of the Study: Climatic and geological changes have been considered as major drivers of biological diversification. However, it has been generally assumed that lineages retain common environmental affinities, suggesting a limited capacity to switch their climatic niche. We tested this assumption with a study of the evolution of climatic niches in the Neotropical tree genus Cedrela (Meliaceae). • Methods: We combined distribution models of extant Cedrela with a dated molecular phylogeny based on one nuclear (ITS) and three plastid markers (psbA-trnH, trnS-G and psbB-T-N) to reconstruct the evolutionary dynamics of climatic niches. We calculated relative disparity of climatic tolerances over time to test for niche evolution within subclades or divergence between subclades and conservatism among closely related groups. Published fossil records and studies on paleosols were evaluated for the distribution and climatic conditions of extinct Cedrela. • Key results: The fossil record of Cedrela suggested a major biome shift from paratropical conditions into warm-temperate seasonal climates in the Early Oligocene of western North America. In the Miocene, Cedrela extended from North America (John Day Formation, Oregon, USA) to southern Central America (Gatún, Panama). Diversification in the early evolutionary history was mainly driven by changes in precipitation. Temperature had an increasing impact on ecological diversification of the genus from the Miocene onwards. Sister-species comparisons revealed that recent speciation events may be related to divergence of climatic tolerances. • Conclusions: Our study highlights the complexity of climatic niche dynamics, and shows how conservatism and evolution have acted on different temporal scales and climatic parameters in Cedrela. PMID:24018859

Koecke, A Valerie; Muellner-Riehl, Alexandra N; Pennington, Terence D; Schorr, Gertrud; Schnitzler, Jan

2013-09-09

4

Mesozoic sedimentary rocks and depositional facies, Vizcaino-Cedros Area, Baja California, Mexico  

Microsoft Academic Search

Mesozoic sedimentary rocks in the Vizcaino-Cedros area constitute a 135-m.y. history of arc-related marine sedimentation with a cumulative thickness of 14 km. The Upper Triassic San Hipolito Formation is the oldest sedimentary unit in the region, and is recognized only on the Vizcaino Peninsula. The formation depositionally overlies an ophiolite sequence and consists of 2.4 km of tuffaceous sediment including

J. R. Boles

1986-01-01

5

Paleomagnetism of mesozoic red chert from Cedros Island and the San Benito Islands, Baja California, Mexico revisited  

NASA Astrophysics Data System (ADS)

Previous paleomagnetic study of Mesozoic subduction-complex rocks on Cedros Island and the San Benito Islands, Mexico, shows that these rocks have been remagnetized; a single-polarity magnetization was found in chert sections and underlying pillow basalt deposited during a mixed-polarity interval of the geomagnetic field. Reanalysis of the Cedros and San Benito chert samples (101 total) shows that 13 samples also retain a high blocking-temperature component of magnetization (600° to 680°C) indicating a polarity stratigraphy and deposition of the bedded chert near 2° ± 3° paleolatitude. These data are similar to those for red chert in California and Japan implying that many of the Mesozoic ophiolitic chert sequences now exposed around the Pacific rim were initially deposited within the equatorial zone of high biologic productivity. These new data also support accretion of the Cedros and San Benito chert to the American margin at tropical paleolatitudes requiring significant northward translation (and clockwise rotation) to bring them to their present position with respect to the continental interior.

Hagstrum, Jonathan T.; Sedlock, Richard L.

1992-02-01

6

Induction of somatic embryogenesis and plant regeneration in the tropical timber tree Spanish red cedar [ Cedrela odorata L. (Meliaceae)  

Microsoft Academic Search

Spanish red cedar (Cedrela\\u000a odorata L.) is a tropical timber tree native to the Americas from southern Mexico to northern Argentina. Commercial plantations are\\u000a scarce and, consequently, natural populations are overexploited. Traditional propagation practices for the establishment of\\u000a large-scale plantations have had limited success in this species due to the relative scarcity of seeds, its broad genetic\\u000a diversity and the

Yuri J. Peña-Ramírez; Israel García-Sheseña; Ángel Hernández-Espinoza; Alfredo Domínguez-Hernández; Felipe A. Barredo-Pool; José A. González-Rodríguez; Manuel L. Robert

2011-01-01

7

Irradiance heterogeneity within crown affects photosynthetic capacity and nitrogen distribution of leaves in Cedrela sinensis.  

PubMed

Because light conditions in the forest understory are highly heterogeneous, photosynthetic acclimation to spatially variable irradiance within a crown is important for crown-level carbon assimilation. The effect of variation in irradiance within the crown on leaf nitrogen content and photosynthetic rate was examined for pinnate compound leaves in saplings of Cedrela sinensis, a pioneer deciduous tree. Five shading treatments, in which 0, 25, 50, 75 and 100% of leaves were shaded, were established by artificial heavy shading using shade screen umbrellas with 25% transmittance. Although the nitrogen content of leaves was constant regardless of shading treatment, ribulose 1.5-bisphosphate carboxylase/oxygenase (Rubisco) content and light-saturated photosynthetic capacity were lower in shade leaves within partially shaded crowns than within fully shaded crowns. Shade leaves within partially shaded crowns contained higher amount of amino acids. Most shade leaves died in partially shaded crowns, whereas more than half of shade leaves survived in totally shaded crowns. Assumptions on photosynthetic acclimation to local light conditions cannot explain why shade leaves have different photosynthetic capacities and survival rates in between partially and totally shaded crowns. Irradiance heterogeneity within the crown causes a distinct variation in photosynthetic activity between sun and shaded leaves within the crown. PMID:20519020

Yoshimura, Kenichi

2010-05-01

8

Geochemistry of the Mesozoic bedded cherts of Central Baja California (Vizcaino-Cedros-San Benito): implications for paleogeographic reconstruction of an old oceanic basin  

NASA Astrophysics Data System (ADS)

In central Baja California (Vizcaino Peninsula, and Cedros and San Benito Islands) two distinct radiolarian bedded chert sequences of late Triassic and late Jurassic/lowermost Cretaceous age, can be differentiated on lithostratigraphic and geochemical criteria. These bedded chert sequences are part of the conformable sedimentary cover of more or less dismembered ophiolites, which are overthrusted by the San Andrès-Cedros volcanic arc system of middle late Jurassic age. Major and trace elements permit paleogeographic zonation of the late Jurassic/lowermost Cretaceous radiolarites lying conformably upon ophiolites considered as fragments of an oceanic basin floor which developed westward of the San Andrès volcanic arc. Progressive accretion of this oceanic basin floor, along the continental margin is supported by the fact that the more distal radiolarian chert sequences belong to the lowermost structural units of this area. Also Groupe des Sciences de la Terre, Laboratoire Pierre Sue, Saclay.

Rangin, Claude; Steinberg, Michel; Bonnot-Courtois, Chantal

1981-07-01

9

Tectonic significance of large-scale chaotic deposits in a Cretaceous fore-arc basin: Valle Formation, Cedros Island (Mexico)  

SciTech Connect

A mappable, deep-marine slide deposit (olistostrome) within medial-Cretaceous fore-arc basin strata (Valle Formation), located on Cedros Island, Baja California Norte, records the initiation of intrabasinal faulting. Studies of both modern and ancient olistostromes show that olistostromes can form in all physiographic provinces (including shelf and abyssal plain) and tectonic settings of the marine environment. A variety of triggering mechanisms have been suggested for olistostromes, including tectonism, sea level changes, diapirism, rapid sedimentation that overloads steep slopes, migration of gas hydrates, or combinations of the above. The olistostrome in the Valle Formation ranges in thickness from 0 to at least 180 m, and extends areally for at least 34 km{sup 2}. It can be divided into two parts. The basal 30-40 m contains large (up to 8 m) angular blocks (allolistoliths) derived from the Jurassic substrate. The allolistoliths decrease in abundance upsection, whereas internally coherent intraformational slide blocks (endolistoliths), which reach tens of meters in width, increase. Beds composing the endolistoliths are alternating mudstone and sandstone turbidites that were deposited on a tectonically stable basin plain or rise setting before catastrophic failure of the sedimentary pile produced the olistostrome. Intrabasinal faulting is invoked as a cause of the sediment failure because of the presence of allolistoliths, which must have been shed into the basin from uplifted( ) basin floor scarps. Allolistoliths occur sporadically throughout at least 400 m of coarse-clastic sediment gravity-flow deposits that cap the olistostrome, suggesting that intrabasinal faulting continued to affect the basin long after the olistrostrome formed.

Smith, D.P.; Busby-Spera, C.J. (Univ. of California, Santa Barbara (USA))

1990-05-01

10

Identification of endangered or threatened Costa Rican tree species by wood anatomy and fluorescence activity.  

PubMed

A total of 45 native Costa Rican tree species are threatened or in danger of extinction, but the Convention on International Trade Endangered Species (CITES) includes only eight of these in its Appendices. However, the identification of other species based on their wood anatomy is limited. The present study objective was to describe and to compare wood anatomy and fluorescence activity in some endangered or threatened species of Costa Rica. A total of 45 (22 endangered and 23 threatened with extinction) wood samples of these species, from the xylaria of the Instituto Tecnológico de Costa Rica and the Forest Products Laboratory in Madison, Wisconsin, were examined. Surface fluorescence was positive in eight species, water extract fluorescence was positive in six species and ethanol extract fluorescence was positive in 24 species. Almost all species were diffuse porous except for occasional (Cedrela odorata, C. fissilis, Cordia gerascanthus) or regular (C. salvadorensis and C. tonduzii) semi-ring porosity. A dendritic vessel arrangement was found in Sideroxylon capari, and pores were solitary in Guaiacum sanctum and Vantanea barbourii. Vessel element length was shortest in Guaiacum sanctum and longest in Humiriastrum guianensis, Minquartia guianensis and Vantanea barbourii. Finally, anatomical information and fluorescence activity were utilized to construct an identification key of species, in which fluorescence is a feature used in identification. PMID:24027913

Moya, Róger; Wiemann, Michael C; Olivares, Carlos

2013-09-01

11

The lepidoptera associated with forestry crop species in Brazil: a historical approach.  

PubMed

Despite the long history of forestry activity in Brazil and its importance to the national economy, there is still much disorder in the information regarding pests of forestry species. Considering the importance of the entomological knowledge for the viability of silvicultural management, this work aimed to gather information on the species of Lepidoptera associated with forestry crops within Brazil using a historical approach. Through a literature review, all registered species of Lepidoptera related to forestry crops in Brazil from 1896 to 2010 were identified. The historical evaluation was based on the comparison of the number of published articles, species richness, and community similarities of the Lepidoptera and their associated forest crops, grouped in 10-year samples. A total of 417 occurrences of Lepidoptera associated with forestry species were recorded, from which 84 species are related with 40 different forestry crops. The nocturnal Lepidoptera were dominant on the records, with Eacles imperialis magnifica Walker as the most frequent pest species cited. Myrtaceae was the most frequent plant family, with Cedrela fissilis as the most cited forestry crop species. A successional change in both Lepidoptera species and their host plants was observed over the decades. The richness of lepidopteran pest species increased over the years, unlike the richness of forestry crop species. This increase could be related to the inefficient enforcement of sanitary barriers, to the increase of monoculture areas, and to the adaptability of native pests to exotic forestry species used in monoculture stands. PMID:23950084

Kowalczuck, Manoela; Carneiro, E; Casagrande, M M; Mielke, O H H

2012-07-06

12

Coordination between water-transport efficiency and photosynthetic capacity in canopy tree species at different growth irradiances.  

PubMed

Plasticity in hydraulic architecture of five dominant Atlantic forest species differing in light requirements and growth rates was evaluated in saplings grown at different irradiances to determine if hydraulic architecture changes in coordination with photosynthetic capacity. Saplings were grown in shade-houses at 10, 30, 45 and 65% of full solar irradiance for 4 months. In four of the five species, maximum relative growth rates were observed at intermediate irradiances (30 and 40% of full sun). Slow-growing species had lower maximum electron transport rates (ETR(max)) than fast-growing species. A positive correlation between ETR(max) and maximum leaf hydraulic conductivity (K(L)) was found across species, suggesting that species-specific stem hydraulic capacity and photosynthetic capacity were linked. Species with relatively high growth rates, such as Cedrela fissilis Vell., Patagonula americana L. and Cordia trichotoma (Vell.) Arrab. Ex Stend, exhibited increased K(L) and specific hydraulic conductivity (K(S)) with increased growth irradiance. In contrast, K(S) and K(L) did not vary with irradiance in the slower-growing and more shade-tolerant species Balfourodendron riedelianum (Engl.) Engl. and Lonchocarpus leucanthus Burkart, despite a relatively large irradiance-induced variation in ETR(max). A correlation between K(S) and ETR(max) was observed in fast-growing species in different light regimes, suggesting that they are capable of plastic changes in hydraulic architecture and increased water-transport efficiency in response to changes in light availability resulting from the creation of canopy gaps, which makes them more competitive in gaps and open habitats. PMID:17938117

Campanello, Paula I; Gatti, M Genoveva; Goldstein, Guillermo

2008-01-01

13

[Psychological counselling and motivational psychotherapy in the treatment of drug dependence: assessment of interventions with the CEDRO Lugar de Escucha Program].  

PubMed

The objective of the present research is to assess perception of and levels of satisfaction with the Lugar de Escucha program, as well as its brief interventions using counseling and motivational sessions. The study is of a pre-experimental type, with a single-group pretest-posttest measurement design. The sample was made up of 128 participants (9.4% females and 90.6% males), aged 15 to 51 (mean= 23.65; standard deviation = 7.92), users of cannabis, cocaine base paste, cocaine, inhalants and alcohol who attended the program. Data collection was carried out using Attention Forms (FdA); the University of Rhode Island Change Assessment Scale (URICA); the Treatment Satisfaction Questionnaire (CST); and the Cases Follow-up Survey (ESC). In order to evaluate the effectiveness of the Lugar de Escucha Program, we assessed participants' motivational phases during the first interview and at referral, their level of satisfaction with the service received and the percentage of entrance to different treatment programs of the referred participants. The results on perception and satisfaction confirm a predominance of the program's strengths. With regard to the motivational phases, the findings show that the motivational induction interventions help to establish and maintain the patient's motivation for attitude change and for cessation of the abuse. In this sense, according to the findings, such interventions tend to be more effective when applied to patients in the Precontemplational and Contemplational phases. This suggests the need to work with more homogeneous groups, considering type of drugs, age and gender, and to use pre and post instruments. Likewise, the results suggest the need to classify patients in phases of change; such classification could be a useful tool for the improvement of treatment programs for drug users. PMID:18551231

Rojas Valero, Milton; Espinoza Paul, Luis

2008-01-01

14

Endosymbiotic copepods may feed on zooxanthellae from their coral host, Pocillopora damicornis  

NASA Astrophysics Data System (ADS)

The Xarifiidae is one of the most common families of endosymbiotic copepods that live in close association with scleractinian corals. Previous studies on xarifiids primarily focused on their taxonomy and morphology, while their influence on corals is still unknown. In this study, we collected a total of 1,579 individuals belonging to 6 species of xarifiids from 360 colonies of Pocillopora damicornis at Nanwan Bay, southern Taiwan from July 2007 to May 2008. Furthermore, using optical and electron microscopic observations, we examined the gut contents of Xarifia fissilis, the most abundant species of the Xarifiidae that we collected. We found that the gut of X. fissilis was characterized by a reddish-brown color due to the presence of numerous unicellular algae with diameters of 5-10 ?m. TEM observations indicated that the unicellular algae possessed typical characteristics of Symbiodinium including a peripheral chloroplast, stalked pyrenoids, starch sheaths, mesokaryotic nuclei, amphiesmas, an accumulation body, and mitochondria. After starving the isolated X. fissilis in the light and dark (light intensity: 140 ?mol photon m-2 s-1; photoperiod: 12 h light/12 h dark) for 2 weeks, fluorescence was clearly visible in its gut and fecal pellets under fluorescent microscopic observations. The cultivation experiment supports the hypothesis that the unicellular algae were beneficial to the survival of X. fissilis under light conditions, possibly through transferring photosynthates to the hosts. These results suggest that X. fissilis may consume and retain unicellular algae for further photosynthesis.

Cheng, Y.-R.; Dai, C.-F.

2010-03-01

15

Population Size and Trends for Nesting Ospreys in Northwestern Mexico: Region-wide Surveys, 1977, 1992/1993 and 2006.  

National Technical Information Service (NTIS)

We used a double-sampling technique (air plus ground survey) in 2006, with partial double coverage, to estimate the present size of the osprey (Pandion haliaetus) nesting population in northwestern Mexico. With the exception of Natividad, Cedros, and San ...

A. C. Veraan C. J. Henny D. W. Anderson J. L. E. Cartron

2007-01-01

16

In vitro screening of leishmanicidal activity in myanmar timber extracts.  

PubMed

Seventy-five Myanmar timber extracts belonging to 27 families were examined for their leishmanicidal activities. Some timber extracts had significant leishmanicidal activity, especially extracts of Millettia pendula, which exhibited the most potent activity (MLC 3.1 microg/ml, MIC 1.6 microg/ml). Other timber extracts showing potent activity included those from Cedrela serrata, Cedrela toona, Cordia fragrantissima, Calophyllum kunstleri, Dalbergia cultrate, Grevillea robusta, Haplophragma adenophyllum, Michelia champaca, and Tectona grandis. From a literature search for reports on the chemical constituents of these plants, most constituents were found to be quinone derivatives or other compounds with unsaturated carbonyl groups. PMID:15187448

Takahashi, Marii; Fuchino, Hiroyuki; Satake, Motoyoshi; Agatsuma, Yutaka; Sekita, Setsuko

2004-06-01

17

Lithofacies of deep marine basalts emplaced on a Jurassic backarc apron, Baja California (Mexico)  

Microsoft Academic Search

Basalts of the mid-Jurassic Gran Canon Formation, Cedros Island, Mexico, were emplaced on a volcaniclastic apron in a deep marine backarc basin. Elongate pillows and lava tubes, as well as paleocurrent data from the volcaniclastic apron, indicate a southward regional paleoslope away from the island arc source. Basalts emplaced on relatively proximal parts of the apron are nearly entirely pillowed

Cathy J. Busby-Spera

1987-01-01

18

Evolution of subsidence styles in forearc basin: example from Cretaceous of southern Vizcaino Peninsula, Baja California, Mexico  

Microsoft Academic Search

Late Jurassic to Early Cretaceous arc magmatism is represented by volcaniclastic rocks of the Eugenia Formation in the northern Vizcaino Peninsula and by the metamorphosed Cedros-San Andres volcanoplutonic complex, with a dismembered ophiolitic basement, in the southern peninsula. The Vizcaino Peninsula became the site of forearc sedimentation by the Aptian-Albian (late Early Cretaceous), when arc magmatism moved abruptly eastward to

C. J. Busby-Spera; J. R. Boles

1986-01-01

19

A new species of Jahnulales from Las Ilusiones Lagoon, Tabasco, Mexico  

Technology Transfer Automated Retrieval System (TEKTRAN)

During a study on biodiversity of freshwater ascomycetes from an urban tropical lagoon, an ascomycete with similar morphology to species of Jahnulales was obtained. Smooth surface test blocks of Pinus sp., Bucida sp., Cedrela sp. and Tabebuia sp. were submerged in pairs close to a private house whar...

20

Antifeedant activity of Quassia amara (Simaroubaceae) extracts on Hypsipyla grandella (Lepidoptera: Pyralidae) larvae  

Microsoft Academic Search

The inhibitory effect of methanolic wood and leaf extracts of bitterwood tree (Quassia amara) on mahogany shootborer (Hypsipyla grandella) larval feeding and growth was studied. A randomized complete block design, with four replications, was used. H. grandella third instar larvae were exposed for 24 h to Cedrela odorata leaf discs dipped in several treatment dissolutions of each extract (0.1, 0.316,

Fernando Mancebo; Luko Hilje; Gerardo A Mora; Rodolfo Salazar

2000-01-01

21

Somatic embryogenesis and plant regeneration from pistil thin cell layers of Citrus  

Microsoft Academic Search

Callus induction, somatic embryogenesis and plant regeneration were obtained in six different citrus species [Citrus deliciosa Ten. (cv 'Avana'), C.limon (L.) Burm. (cv 'Berna'), C.madurensis Lour. (cv 'CNR P9'), C.medica L. (cv 'Cedro di Trabia'), C.tardiva Hort. ex Tan. (cv 'CNR P6'), C.sinensis (L.) Osb. (cv 'Ugdulena 7')] from cultures of pistil transverse thin cell layer explants [(t)TCL]. Explants were

F. Carimi; F. De Pasquale; F. G. Crescimanno

1999-01-01

22

Latitudinal variations of the yield and quality of agar from Gelidium robustum (Gelidiales, Rhodophyta) from the main commercial harvest beds along the western coast of the Baja California Peninsula, Mexico  

Microsoft Academic Search

The yield and quality of agar from Gelidium robustum from the main commercial harvest beds along the western coast of the Baja California Peninsula (Mexico) were evaluated within\\u000a a latitudinal range of about 800 km (31°47?N to 27°05?N). Samples from six locations, Bahía Todos Santos, El Rosario, Isla\\u000a de Cedros, Islas San Benito, Punta Eugenia, and Bahía Asunción, were analyzed. Bryozoan,

Miguel Ángel Hurtado; Marlenne Manzano-Sarabia; Enrique Hernández-Garibay; Isaí Pacheco-Ruíz; José A. Zertuche-González

23

Biological activity of two neem ( Azadirachta indica A. Juss., Meliaceae) products on Hypsipyla grandella (Lepidoptera: Pyralidae) larvae  

Microsoft Academic Search

Biological activity of two neem products (Azatin and Nim 80) on mahogany shootborer (Hypsipyla grandella) larvae was studied. A randomized complete block design, with four replications, was used. H. grandella third instar larvae were exposed for 24h to Cedrela odorata leaf discs dipped in several treatment dissolutions of each formulated product (0.1, 0.32, 1.0, 3.20, and 10%); afterwards, each larva

Fernando Mancebo; Luko Hilje; Gerardo A Mora; Rodolfo Salazar

2002-01-01

24

Antifungal Activity of 10 Guadeloupean Plants.  

PubMed

Screening of the antifungal activities of ten Guadeloupean plants was undertaken to find new extracts and formulations against superficial mycoses such as onychomycosis, athlete's foot, Pityriasis versicolor, as well as the deep fungal infection Pneumocystis pneumonia. For the first time, the CMI of these plant extracts [cyclohexane, ethanol and ethanol/water (1:1, v/v)] was determined against five dermatophytes, five Candida species, Scytalidium dimidiatum, a Malassezia sp. strain and Pneumocystis carinii. Cytotoxicity tests of the most active extracts were also performed on an HaCat keratinocyte cell line. Results suggest that the extracts of Bursera simaruba, Cedrela odorata, Enterolobium cyclocarpum and Pluchea carolinensis have interesting activities and could be good candidates for developing antifungal formulations. Copyright © 2012 John Wiley & Sons, Ltd. PMID:23280633

Biabiany, Murielle; Roumy, Vincent; Hennebelle, Thierry; François, Nadine; Sendid, Boualem; Pottier, Muriel; Aliouat, El Moukhtar; Rouaud, Isabelle; Lohézic-Le Dévéhat, Françoise; Joseph, Henry; Bourgeois, Paul; Sahpaz, Sevser; Bailleul, François

2012-12-27

25

[Lipid and fatty acid profile of Perna viridis, green mussel (Mollusca: Bivalvia) in different areas of the Eastern Venezuela and the West Coast of Trinidad].  

PubMed

The species Perna viridis is a highly consumed species, which fast growth makes it an interesting aquaculture alternative for Venezuelan and Trinidad coasts. With the aim to contribute with its nutritional value information, this study analyzed lipid and fatty acid contents from samples taken in five locations from Eastern Venezuela and three from Trinidad West Coast. Total lipids were extracted and quantified, from a pooled sample of 100 organisms per location, by standard gravimetric methods, and their identification and quantification was done by TLC/FID (Iatroscan system). Furthermore, the esterified fatty acids of total lipid, phospholipids and triacylglycerols were identified and quantified by gas chromatography. Eastern Venezuela samples from Los Cedros, La Brea and Chaguaramas showed the highest total lipid values of 7.92, 7.74 and 7.53, respectively, and the minimum values were obtained for La Restinga (6.08%). Among lipid composition, Chacopata samples showed the lowest phospholipid concentration (48.86%) and the maximum values for cholesterol (38.87%) and triacylglycerols (12.26%); besides, La Esmeralda and Rio Caribe samples exhibited maximum phospholipids (88.71 and 84.93 respectively) and minimum cholesterol (6.50 and 4.42%) concentrations. Saturated fatty acids represented between 15.04% and 65.55% within total lipid extracts, with maximum and minimum values for La Esmeralda and Chacopata, respectively. Polyunsaturated results resulted between 7.80 and 37.18%, with higher values in La Brea and lower values in La Esmeralda. For phospholipids, saturated fatty acids concentrations varied between 38.81 and 48.68% for Chaguaramas and Chacopata samples, respectively. In the case of polyunsaturated fatty acids, these varied between non detected and 34.51%, with high concentrations in Los Cedros (27.97%) and Chaguaramas (34.51%) samples. For the triacylglycerols, the saturated fatty acids composition oscillated between 14.27 and 53.80% with low concentrations for Chacopata and high concentration for La Restinga; the polyunsaturated fatty acids were between 4.66 and 35.55% with lower values for Chacopata and higher values for Chaguaramas samples. P. viridis is recommended for human being consumption, according to the high content of unsaturated fatty acids found for this species. PMID:21516644

Koftayan, Tamar; Milano, Jahiro; D'Armas, Haydelba; Salazar, Gabriel

2011-03-01

26

Reinterpretation of Mesozoic ophiolite arc, and blueschist terranes in southwestern Baja California  

SciTech Connect

The nature and significance of disrupted Mesozoic oceanic rocks on Isla Santa Margarita and Isla Magdalena, western Baja California Sur, have been reinterpreted on the basis of detailed mapping and petrologic studies. Three structural units are recognized. (1) The upper plate consists of ophiolitic, arc, and forearc basin rocks. Ophiolitic rocks, including metamorphosed ultramafic rocks, gabbro, dikes, volcanic rocks, and chert, underwent strong contractional deformation and penetrative greenschist-facies metamorphism. Arc rocks, including gabbro, a dike and sill complex, compositionally diverse volcanic rocks, lahars, and volcaniclastic strata, lack a penetrative fabric and are weakly metamorphosed. Forearc basin rocks consist of unmetamorphosed conglomerated and rhythmically bedded siliciclastic turbidites. (2) The lower plate is a subduction complex consisting of weakly to moderately foliated and metamorphosed pillow and massive lavas, breccia, and tuff( ), interbedded red and green siliceous argillite, and rare radiolarian ribbon chert and limestone. Blueschist-facies metamorphism is indicated by lawsonite, aragonite, sodic amphibole, and sodic clino-pyroxene. (3) Serpentine-matrix melange crops out in shallowly dipping fault zones between the upper and lower plates. The structural and petrologic characteristics of the Mesozoic units, the geometry of contacts between them, and the age of extension are similar to those in the Isla Cedros-Vizcalno Peninsula region, 400 km to the northwest. The author infers that syn-subduction extension was a regional event that affected much of the western Baja forearc during the Late Cretaceous and Paleogene.

Sedlock, R.L. (San Jose State Univ., CA (United States). Geology Dept.)

1993-04-01

27

Lithofacies of deep marine basalts emplaced on a Jurassic backarc apron, Baja California (Mexico)  

SciTech Connect

Basalts of the mid-Jurassic Gran Canon Formation, Cedros Island, Mexico, were emplaced on a volcaniclastic apron in a deep marine backarc basin. Elongate pillows and lava tubes, as well as paleocurrent data from the volcaniclastic apron, indicate a southward regional paleoslope away from the island arc source. Basalts emplaced on relatively proximal parts of the apron are nearly entirely pillowed and have thick flow units with mega-pillows. Basalts on distal parts of the apron (about 15 to 20 km down paleo-current) are dominated by pillow fragment breccias (flow foot rubble), and individual lava flows are generally thin, with small pillows, suggesting that the distal ends of lava flows, erupted upslope, are represented. These distal flow fronts, however, are interstratified with features that typically form close to a vent, including thick massive to mega-pillowed lavas and lava tubes up to 8 m in diameter. It is inferred that a fissure (or system of fissures) extended from the arc into the backarc basin, erupting basalt lavas onto both proximal and distal parts of the volcaniclastic apron. Such intraplate volcanism may be common on the hot frontal arc side of backarc basins. 26 references.

Busby-Spera, C.J.

1987-09-01

28

The P-T-t history of blocks in serpentinite-matrix melange, west-central Baja California  

SciTech Connect

Thermochronologic, petrologic, and geochemical analyses of epidote-amphibolite-, amphilbolite-, eclogite-, and blueschist-facies blocks in serpentinite-matrix melanges from East San Benito Island and Cedros Island, west-central Baja California, provide constraints on the P-T-t history of this disrupted terrane. Results of {sup 40}Ar/{sup 39}Ar step heating experiments on minerals separated from these blocks vary according to metamorphic grade and indicate different P-T-t histories. Mid-Jurassic (160-170 Ma) epidote-amphibolite- and amphibolite-facies blocks were probably derived from oceanic crust and associated sediments that were metamorphosed during limitation of subduction. Coarse-grained blueschist blocks were likely metamorphosed during continued subduction in late Early Cretaceous time (that is, 115-100 Ma). Some epidote-amphibolite blocks are partially overprinted by blueschist-facies mineral assemblages and apparently record both metamorphic events. Fission-track analyses of apatites indicate that the blocks underwent significantly different post-metamorphic cooling histories. Epidote-amphilbolite and amphibolite blocks cooled below {approximately}100 {degrees}C form mid-Jurassic to Paleocene time; blueschist blocks cooled below {approximately}100 {degrees}C in Oligocene-Miocene time. In general, mafic blocks have trace-element concentrations and REE patterns characteristic of ocean-flood basalts. This study demonstrates that samples with very different P-T-t histories can evidently occur over relatively small length scales (<<1 km) in serpentinite-matrix melanges. 67 refs., 16 figs., 4 tabs.

Baldwin, S.L.; Harrison, T.M. [State Univ. of New York, Albany, NY (United States)

1992-01-01

29

The influence of mesoscale physical structures in the phytoplankton taxonomic composition of the subsurface chlorophyll maximum off western Baja California  

NASA Astrophysics Data System (ADS)

The distribution of the subsurface chlorophyll maximum (SCM) layer, its taxonomic phytoplankton composition, and the maximum quantum efficiency of charge separation of PSII (Fv/Fm) was investigated in the west coast off Baja California during October 2003. SCM characteristics were described and related to the hydrographic regime and the mesoscale physical structures present during this period. Seven groups of phytoplankton were detected in the SCM based on chemotaxonomic analysis of pigment fingerprints: diatoms, haptophytes, pelagophytes, prasinophytes, cryptophytes, Prochlorococcus and cyanobacteria. The distribution of these groups was heterogeneous and closely related to the circulation patterns characterized by the interaction of subarctic and tropical water. Eddies and meanders were detected in the study area and these structures exerted a direct response in the depth, chlorophyll concentration, and photosynthetic competence of phytoplankton in the SCM. A cyclonic eddy characterized by a high chlorophyll concentration (1.6 mg m-3) and high values of Fv/Fm, (0.52) was detected in the northern zone of the study area. In the central zone, a cyclonic eddy (1.2 mg m-3); and other structure resembling a mode-water eddy was located northwest of Cedros Island. This structure presented the highest chlorophyll concentration (1.8 mg m-3) and high Fv/Fm (˜0.5). Chlorophyll concentration and the photosynthetic performance of the phytoplankton community was lower outside of these eddies. Cyanobacteria dominated the phytoplankton SCM community in these areas.

Almazán-Becerril, Antonio; Rivas, David; García-Mendoza, Ernesto

2012-12-01

30

Use of grafting to prevent Hypsipyla grandella (Zeller) (Lepidoptera: Pyralidae) damage to new world Meliaceae species.  

PubMed

The susceptible species Cedrela odorata and Swietenia macrophylla to attack by Hypsipyla grandella (Zeller) larvae were grafted onto the resistant species Khaya senegalensis and Toona ciliata. Six-month-old grafted plants were then compared to their reciprocal grafts and to both intact (non-grafted) and autografted plants for damage due to H. grandella larvae and for their effects on larval performance. Two experiments were conducted: one in which the apical bud of the main plant shoot was inoculated with H. grandella eggs, and the other in which the bud was inoculated with third instars. Damage in each experiment was assessed by the number of frass piles, number and length of tunnels, number of damaged leaves, and damage to the apical bud. Larval performance was evaluated in terms of time to reach pupation and pupal weight and length. In both experiments, plant damage differed significantly among treatments (P < 0.03). Resistant rootstocks conferred resistance to susceptible scions. In both experiments, grafting by itself, regardless of the rootstock and scion combination, also reduced damage caused by H. grandella larvae. Scions of autografted susceptible species had similar resistance to susceptible scions grafted on resistant rootstocks. Few larvae reached pupation, and their pupal weight and length were similar. PMID:20878001

Perez, Julian; Eigenbrode, Sanford D; Hilje, Luko; Tripepi, Robert R; Aguilar, Maria E; Mesen, Francisco

31

Oxygen isotopes in tree rings are a good proxy for Amazon precipitation and El Nino-Southern Oscillation variability.  

PubMed

We present a unique proxy for the reconstruction of variation in precipitation over the Amazon: oxygen isotope ratios in annual rings in tropical cedar (Cedrela odorata). A century-long record from northern Bolivia shows that tree rings preserve the signal of oxygen isotopes in precipitation during the wet season, with weaker influences of temperature and vapor pressure. Tree ring ?(18)O correlates strongly with ?(18)O in precipitation from distant stations in the center and west of the basin, and with Andean ice core ?(18)O showing that the signal is coherent over large areas. The signal correlates most strongly with basin-wide precipitation and Amazon river discharge. We attribute the strength of this (negative) correlation mainly to the cumulative rainout processes of oxygen isotopes (Rayleigh distillation) in air parcels during westward transport across the basin. We further find a clear signature of the El Niño-Southern Oscillation (ENSO) in the record, with strong ENSO influences over recent decades, but weaker influence from 1925 to 1975 indicating decadal scale variation in the controls on the hydrological cycle. The record exhibits a significant increase in ?(18)O over the 20th century consistent with increases in Andean ?(18)O ice core and lake records, which we tentatively attribute to increased water vapor transport into the basin. Taking these data together, our record reveals a fresh path to diagnose and improve our understanding of variation and trends of the hydrological cycle of the world's largest river catchment. PMID:23027960

Brienen, Roel J W; Helle, Gerd; Pons, Thijs L; Guyot, Jean-Loup; Gloor, Manuel

2012-10-01

32

Oxygen isotopes in tree rings are a good proxy for Amazon precipitation and El Ni?o-Southern Oscillation variability  

PubMed Central

We present a unique proxy for the reconstruction of variation in precipitation over the Amazon: oxygen isotope ratios in annual rings in tropical cedar (Cedrela odorata). A century-long record from northern Bolivia shows that tree rings preserve the signal of oxygen isotopes in precipitation during the wet season, with weaker influences of temperature and vapor pressure. Tree ring ?18O correlates strongly with ?18O in precipitation from distant stations in the center and west of the basin, and with Andean ice core ?18O showing that the signal is coherent over large areas. The signal correlates most strongly with basin-wide precipitation and Amazon river discharge. We attribute the strength of this (negative) correlation mainly to the cumulative rainout processes of oxygen isotopes (Rayleigh distillation) in air parcels during westward transport across the basin. We further find a clear signature of the El Niño-Southern Oscillation (ENSO) in the record, with strong ENSO influences over recent decades, but weaker influence from 1925 to 1975 indicating decadal scale variation in the controls on the hydrological cycle. The record exhibits a significant increase in ?18O over the 20th century consistent with increases in Andean ?18O ice core and lake records, which we tentatively attribute to increased water vapor transport into the basin. Taking these data together, our record reveals a fresh path to diagnose and improve our understanding of variation and trends of the hydrological cycle of the world’s largest river catchment.

Brienen, Roel J. W.; Helle, Gerd; Pons, Thijs L.; Guyot, Jean-Loup; Gloor, Manuel

2012-01-01

33

NoWMex: Continuous GNSS Sites in Northwest Mexico  

NASA Astrophysics Data System (ADS)

Nowadays GPS has become part of daily life activities. In the near future, with the GPS modernization and the use of Glonass and Galileo as a Global Navigation Satellite System will give relative location precision from decimeters to millimeters in near real time applications. In order to realize this, we need a global array of continuously operating GNSS stations built to meet the standards of the geophysical communities and linked with gravimetric local measurements to discern the vertical component of our active Earth. Trying to follow this revolution, CICESE has been working with GPS since 1985. The GPS site CICE was built as an IGS reference station in 1995. Afterward we built 5 more continuous GPS sites in Northwest Mexico with the support of SCIGN. The CGPS NoWMex network is currently made up of six sites: CIC1, SPMX, CORX, GUAX, USMX and YESX (sopac.ucsd.edu). Recently, we implemented an experimental GPS processing lab as part of the Geodesy and Geodynamics Laboratory in the Seismology Department at CICESE. 30 stations are now currently processed from the network Red Geodesica Nacional Activa (RGNA-INEGI), NoWMex, and sites in neighbor countries. Fiducials solutions in ITRF2000 are obtained using GAMIT/GLOBK 10.31 with final igs orbits, every month since 2006. In order to make a contribution to densification of ITRF and support NAREF, SIRGAS and SNARF issues related to scientific and geomatics results; we are looking for internal (Mexican) and external colleagues as well as funding for maintenance and increase the number of CGNSS in NoWMeX including southern Basin and Ranger (Sonora, Chihuahua, Sinaloa and Durango), Gulf of California islands, Peninsular Californias, Nayarit, Jalisco, Colima and the Mexican Pacific islands: Guadalupe (2 more sites), Cedros, Socorro (DORIS site), Clarion and Tres Marias. We must to build more and free available CGNSS sites in and around Mexico to contribute to sea level rise and global change studies.

Gonzalez-Garcia, J. J.; Gonzalez-Ortega, J. A.

2008-05-01

34

Evolution of subsidence styles in forearc basin: example from Cretaceous of southern Vizcaino Peninsula, Baja California, Mexico  

SciTech Connect

Late Jurassic to Early Cretaceous arc magmatism is represented by volcaniclastic rocks of the Eugenia Formation in the northern Vizcaino Peninsula and by the metamorphosed Cedros-San Andres volcanoplutonic complex, with a dismembered ophiolitic basement, in the southern peninsula. The Vizcaino Peninsula became the site of forearc sedimentation by the Aptian-Albian (late Early Cretaceous), when arc magmatism moved abruptly eastward to the present-day Peninsular Range. On the southern Vizcaino Peninsula, a conformable stratigraphic section, complicated by later faulting, records a gradual transition from a ridged forearc, broken by basement uplifts and grabens (the Aptian-Albian Asunction Formation), to a broadly subsiding, deep marine forearc basin (the Cenomanian Valle Formation). The basal contact of the Asunction formation has irregular relief caused by brecciated basement rocks and talus accumulated along fault zones. An upward-fining sequence several hundred meters thick records abrupt uplift and gradual denudation of adjacent metamorphic basement. Contemporaneous andesite arc volcanism to the east supplied ash and fresh volcanic detritus to the grabens. Angular sand to boulder-size detritus of the Asunction Formation was derived locally, and includes basic to intermediate meta-igneous rock fragments, with epidote, actinolite, and chlorite, as well as serpentine. Abundant calcareous fossils are commonly unbroken, suggesting local sources for these as well. Angular to subrounded, sand to cobble-sized, intermediate to mafic volcanic rock fragments were derived from a more distant island arc to the east, which occasionally provided intermediate to felsic tuffs to the basin. This source is probably represented by the Aptian-Albian Alisitos Group, which forms much of the western wall of the Late Cretaceous Peninsular Range batholith.

Busby-Spera, C.J.; Boles, J.R.

1986-04-01

35

Attaining the canopy in dry and moist tropical forests: strong differences in tree growth trajectories reflect variation in growing conditions  

PubMed Central

Availability of light and water differs between tropical moist and dry forests, with typically higher understorey light levels and lower water availability in the latter. Therefore, growth trajectories of juvenile trees—those that have not attained the canopy—are likely governed by temporal fluctuations in light availability in moist forests (suppressions and releases), and by spatial heterogeneity in water availability in dry forests. In this study, we compared juvenile growth trajectories of Cedrela odorata in a dry (Mexico) and a moist forest (Bolivia) using tree rings. We tested the following specific hypotheses: (1) moist forest juveniles show more and longer suppressions, and more and stronger releases; (2) moist forest juveniles exhibit wider variation in canopy accession pattern, i.e. the typical growth trajectory to the canopy; (3) growth variation among dry forest juveniles persists over longer time due to spatial heterogeneity in water availability. As expected, the proportion of suppressed juveniles was higher in moist than in dry forest (72 vs. 17%). Moist forest suppressions also lasted longer (9 vs. 5 years). The proportion of juveniles that experienced releases in moist forest (76%) was higher than in dry forest (41%), and releases in moist forests were much stronger. Trees in the moist forest also had a wider variation in canopy accession patterns compared to the dry forest. Our results also showed that growth variation among juvenile trees persisted over substantially longer periods of time in dry forest (>64 years) compared to moist forest (12 years), most probably because of larger persistent spatial variation in water availability. Our results suggest that periodic increases in light availability are more important for attaining the canopy in moist forests, and that spatial heterogeneity in water availability governs long-term tree growth in dry forests. Electronic supplementary material The online version of this article (doi:10.1007/s00442-009-1540-5) contains supplementary material, which is available to authorized users.

Zuidema, Pieter A.; Martinez-Ramos, Miguel

2009-01-01

36

Antileishmanial, antitrypanosomal, and cytotoxic screening of ethnopharmacologically selected Peruvian plants.  

PubMed

Extracts (34) from eight plant species of the Peruvian Amazonia currently used in traditional Peruvian medicine, mostly as antileishmanial remedies and also as painkiller, antiseptic, antipyretic, anti-inflamatory, antiflu, astringent, diuretic, antipoison, anticancerous, antiparasitic, insecticidal, or healing agents, have been tested for their antileishmanial, antitrypanosomal, and cytotoxic activity. Plant species were selected based on interviews conducted with residents of rural areas. The different plant parts were dried, powdered, and extracted by maceration with different solvents (hexane, chloroform, and 70% ethanol-water). These extracts were tested on promastigote forms of Leishmania infantum strain PB75, epimastigote forms of Trypanosoma cruzi strain Y, and the mammalian CHO cell line. Parasite viability and nonspecific cytotoxicity were analyzed by a modified MTT colorimetric assay method. The isolation and identification of pure compounds from selected extracts were performed by column chromatography, gas chromatography mass spectrometry (GC-MS; mixtures), spectroscopic techniques [MS, infrared (IR), ultraviolet (UV)], and mono and two-dimensional (1)H and (13)C nuclear magnetic resonance (NMR; COSY, HSQC, NOESY) experiments. Chondodendron tomentosum bark and Cedrela odorata were the most active extracts against Leishmania, while C. odorata and Aristoloquia pilosa were the most active against Trypanosoma, followed by Tabebuia serratifolia, Tradescantia zebrina, and Zamia ulei. Six compounds and two mixtures were isolated from Z. ulei [cycasin (1)], T. serratifolia {mixtures 1-2, and naphthoquinones 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione (2) and 2-(1-hydroxyethyl)-4H,9H-naphtho[2,3-b]furan-4,9-dione (3)}, and C. tomentosum [chondrocurine (4); (S,S')-12-O-methyl(+)-curine (5); and cycleanine (6)]. Four compounds and the two mixtures exhibited significant activity. PMID:21922239

González-Coloma, Azucena; Reina, Matías; Sáenz, Claudia; Lacret, Rodney; Ruiz-Mesia, Lastenia; Arán, Vicente J; Sanz, Jesús; Martínez-Díaz, Rafael A

2011-09-16

37

Insect growth regulatory effects of some extracts and sterols from Myrtillocactus geometrizans (Cactaceae) against Spodoptera frugiperda and Tenebrio molitor.  

PubMed

A methanol extract from the roots and aerial parts of Myrtillocactus geometrizans (Cactaceae) yielded peniocerol 1, macdougallin 2, and chichipegenin 3. The natural products 1, 2 their mixtures, MeOH and CH(2)Cl(2) extracts showed insecticidal and insect growth regulatory activity against fall armyworm [Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae)], an important insect pest of corn, and [Tenebrio molitor (Coleoptera)], a pest of stored grains in Mexico. The most active compounds were 1, 2, and a mixture (M(2)) of 1 and 2 (6:4). All these extracts, compounds and the mixture had insect growth regulating (IGR) activity between 5.0 and 50.0 ppm and insecticidal effects between 50 and 300 ppm in diets. The extracts were insecticidal to larvae, with lethal doses between 100 and 200 ppm. These compounds appear to have selective effects on the pre-emergence metabolism of Coleoptera, because in all treatments of the larvae of T. molitor, pupation were shortened and this process show precociousness in relation to controls. In contrast to S. frugiperda larvae, onset of pupation was noticeably delayed. Emergence in both cases was drastically diminished. In both pupae and in the few adults that were able to emerge, many deformations were observed. The results of these assays indicated that the compounds were more active than other known natural insect growth inhibitors such as gedunin and methanol extracts of Cedrela salvadorensis and Yucca periculosa. Peniocerol, macdougallin and chichipegenin, as well as mixtures of these substances, may be useful as natural insecticidal agents. PMID:16122768

Céspedes, Carlos L; Salazar, J Rodrigo; Martínez, Mariano; Aranda, Eduardo

2005-08-24

38

Population Size and Trends for Nesting Ospreys in Northwestern Mexico: Region-wide Surveys, 1977, 1992/1993 and 2006  

USGS Publications Warehouse

We used a double-sampling technique (air plus ground survey) in 2006, with partial double coverage, to estimate the present size of the osprey (Pandion haliaetus) nesting population in northwestern Mexico. With the exception of Natividad, Cedros, and San Benito Islands along the Pacific Coast of Baja California, all three excluded from our coverage in 2006 due to fog, this survey was a repeat of previous surveys conducted by us with the same protocol in 1977 and 1992/1993 (Baja California surveyed in 1992, Sonora and Sinaloa 1993), allowing for estimates of regional population trends. Population estimates at the 'time of aerial survey' include those nesting, but missed from the air. The population estimate for our coverage area in 2006 was 1,343 nesting pairs, or an 81% increase since 1977, but only a 3% increase since 1992/1993. The population on the Gulf side of Baja California generally remained stable during the three surveys (255, 236 and 252 pairs, respectively). The overall Midriff Islands population remained similar from 1992/1993 (308 pairs) to 2006 (289 pairs), but with notable population changes on the largest two islands (Isla Angel de la Guarda: 45 to 105 pairs [+ 60 pairs]; Isla Tiburon: 164 to 109 pairs [- 55 pairs, or -34%]). The estimated osprey population on the Sonora mainland decreased in a manner similar to adjacent Isla Tiburon, i.e., by 26%, from 214 pairs in 1993 to 158 pairs in 2006. In contrast, the population in Sinaloa, which had increased by 150% between 1977 and 1993, grew again by 58% between 1993 and 2006, from 180 to 285 pairs. Our survey confirmed previously described patterns of rapid population changes at a local level, coupled with apparent shifts in spatial distribution. The large ground nesting population that until recently nested on two islands in San Ignacio Lagoon was no longer present on the islands in 2006, but an equivalent number of pairs were found to the north and south of the lagoon, nesting in small towns and along adjoining power-lines, with no overall change in population size for that general area (198 pairs in 1992; 199 in 2006). Use of artificial nesting structures was 4.3% in 1977 and 6.2% in 1992/1993, but jumped to 26.4% in 2006. Use of power poles poses a risk of electrocution to ospreys as well as causes power outages and fires; modification of power poles to safely accommodate osprey nests has been successful in many countries.

Henny, Charles J.; Anderson, Daniel W.; Vera, Aradit Castellanos; Carton, Jean-Luc E.

2007-01-01

39

Motions of the California Borderland: Results from the SCIGN array  

NASA Astrophysics Data System (ADS)

The California borderland is the geomorphic region offshore Southern California, extending from Point Conception to the Vizcaino Peninsula in Baja California, Mexico. Its western limits are delineated by the Patton escarpment to the north and the Cedros Deep to the south. Except for the west-trending Santa Barbara Channel and Channel Islands, the basin and ridge structures of this 250-km wide zone of rugged topography are largely parallel to the northwest trending coast and the relative motion between the North America and Pacific plates, and are characterized by oblique faulting throughout. We investigate the current motion of the Borderlands region by analyzing continuous data from GPS stations of the SCIGN array located on the Southern California coast and the Channel Islands. After subtracting the interseismic signal due to strain accumulation at the San Andreas, San Jacinto, Elsinore, and Garlock faults from the regional velocity field, we find that the Channel Islands show up to \\(4.5\\pm 0.5\\) mm/yr residual motion relative to the Pacific plate, suggesting that significant shear occurs west of the Channel Islands. Our estimates of the rate of shortening across the Santa Barbara channel (\\(5\\pm 0.4\\) mm/yr), shortening across the Ventura basin (\\(6\\pm 1\\) mm/yr), shortening offshore Ventura basin (\\(1\\pm 0.6\\) mm/yr), and shortening across the LA basin (\\(6\\pm 0.5\\) mm/yr) are similar to previous estimates. Shortening between Palos Verdes and Santa Catalina is \\(1\\pm 0.7\\) mm/yr. Motion between San Diego and San Clemente island is no more than \\(2.7\\pm 0.5\\) mm/yr, lower than Larson's [1993] estimate of \\(5.9\\pm 1.8\\) mm/yr, and is also lower than the combined geological estimates of slip rates on three major faults located in the region (the Coronado Bank, San Diego Trough, and San Clemente faults). If the geological estimates for the Coronado Bank (2 mm/yr) and San Diego Trough (1.5 mm/yr) faults are accurate, our geodetic data do not show the strain accumulation necessary to produce a large earthquake on the San Clemente fault. The recent (August 2001) \\(M\\sim 4\\) earthquakes near San Clemente may indicate that more of the slip occurs on the San Clemente fault.

Prawirodirdjo, L. M.; Bock, Y.; Nikolaidis, R.

2001-12-01

40

Region-wide trends of nesting ospreys in northwestern Mexico: a three-decade perspective  

USGS Publications Warehouse

We used a double-sampling technique (air plus ground survey) in 2006, with partial double coverage, to estimate the present size of the Osprey (Pandion haliaetus) nesting population in northwestern Mexico (coastal Baja California, islands in the Gulf of California, and coastal Sonora and Sinaloa). With the exception of Natividad, Cedros, and San Benitos islands along the Pacific coast of Baja California (all three excluded from our coverage in 2006 due to fog), this survey was a repeat of previous surveys conducted by us with the same protocol in 1977 and 1992/1993, allowing for estimates of regional population trends. The minimum population estimate for the area we surveyed in 2006 was 1343 nesting pairs, an 81% increase since 1977, but only a 3% increase since 1992/1993. The population on the Gulf side of Baja California generally remained stable during the three surveys (255, 236, and 252 pairs, respectively). The population of the Midriff Islands (Gulf of California in the vicinity of 29°N latitude) remained similar from 1992/1993 (308 pairs) to 2006 (289 pairs), but with notable population changes on the largest two islands (Guardian Angel: 45 to 105 pairs [133% increase]; Tiburón: 164 to 109 pairs [34% decrease]). The minimum estimated Osprey population on the Sonora mainland decreased in a manner similar to adjacent Isla Tiburón, i.e., by 26%, from 214 pairs in 1993 to 158 pairs in 2006. In contrast, the population in coastal Sinaloa, which had increased by 150% between 1977 and 1993, grew again by 58% between 1993 and 2006, from 180 to 285 pairs. Our survey confirmed previously described patterns of rapid population changes at a local level, coupled with apparent shifts in spatial distribution. The large ground-nesting population that until recently nested on two islands in San Ignacio Lagoon ( Pacific Ocean side, Baja California) was no longer present on the islands in 2006, but an equivalent number of pairs were found to the north and south of the lagoon, nesting in small towns and along adjoining overhead electric lines, with no overall change in population size for that general area (198 pairs in 1992; 199 in 2006). Use of artificial nesting structures was 4.3% in 1977 and 6.2% in 1992/1993, but jumped to 26.4% in 2006. Use of poles that support overhead electric lines poses a risk of electrocution to Ospreys and also causes power outages and fires. We recommend modification of these poles to safely accommodate Osprey nests, as has been successfully accomplished in many countries.

Henny, Charles J.; Anderson, Daniel W.; Vera, Aradit Castellanos; Cartron, Jean-Luc E.

2008-01-01

41

Tree-ring evidence for long-term precipitation changes in subtropical South America  

NASA Astrophysics Data System (ADS)

In recent years there has been a notable increase in the number of tree-ring chronologies for the temperate and cold regions of the Americas. In comparison, few advances have been reported for the American tropics and subtropics, where the absence of seasonality appears to be the main reason for the lack of well-defined growth bands in most species. Distinct, annually formed tree-rings have recently been reported for subtropical montane trees on the eastern slope of the Andes (22-28°S). Six absolute-dated chronologies from Juglans australis and Cedrela lilloi at the upper treeline (between 1700 and 2000 m) in the montane forest of north-western Argentina were selected to explore the potential of these records to infer decade- to century-scale climatic variations in the subtropics. These tree-rings capture a significant percentage of the variances in regional temperature and precipitation records and appear to be suitable to reconstruct decade-long changes in large-scale circulation over the South American subtropics. In particular, tree-growth at xeric sites has been strongly influenced by precipitation changes, which in turn respond to alternating patterns of zonal versus meridional flows over subtropical South America. The upper treeline records indicate that the increase in precipitation during the past three decades, caused by an enhanced transport of humid air masses from the Brazilian-Bolivian lowland tropics to the semiarid subtropics, has been unprecedented for the past 200 years. Although this precipitation increase may reflect natural variability in the subtropics, it is also consistent with 2×CO2 climatic simulations from five general circulation models. There is a general agreement among model results about a noticeable increase in precipitation in north-western Argentina due to an intensification of the water transport across subtropical South America in response to a southward displacement of the continental low and an increasing warming at these latitudes. A larger network of tree-ring chronologies will aid efforts to understand long-term climatic interactions between tropical and subtropical regions in South America, and shed light on the role of natural versus anthropogenic forcings on regional climatic changes.

Villalba, Ricardo; Grau, Hector R.; Boninsegna, Jose A.; Jacoby, Gordon C.; Ripalta, Alberto

1998-11-01