Sample records for zeolita natural mexicana

  1. Spasmogenic and spasmolytic activities of Agastache mexicana ssp. mexicana and A. mexicana ssp. xolocotziana methanolic extracts on the guinea pig ileum.

    PubMed

    Ventura-Martínez, Rosa; Rodríguez, Rodolfo; González-Trujano, María Eva; Ángeles-López, Guadalupe E; Déciga-Campos, Myrna; Gómez, Claudia

    2017-01-20

    Agastache mexicana has been used in traditional medicine for relief of abdominal pain and treatment of other diseases. Two subspecies have been identified: A. mexicana ssp. mexicana (AMM) and A. mexicana ssp. xolocotziana (AMX) and both are used traditionally without distinction or in combination. To determine the effect of methanol extracts of A. mexicana ssp. mexicana and A. mexicana ssp. xolocotziana on gut motility and their possible mechanism of action. The effect of AMM and AMX methanol extracts were tested on the spontaneous activity in the isolated guinea pig ileum and on tissues pre-contracted with KCl, electrical field stimulation (EFS) or ACh. In addition, the possible mechanism of action of each subspecies on gut motility was analyzed in the presence of hexametonium, indomethacin, L-NAME, verapamil, atropine or pyrylamine. A comparative chromatographic profile of these extracts was also done to indicate the most abundant flavonoids presents in methanol extracts of both subspecies. AMM, but not AMX, induced a contractile effect in the guinea pig ileum. This spasmogenic effect was partially inhibited by atropine, antagonist of muscarinic receptors; and pyrilamine, antagonist of H 1 receptors. In contrast, AMX, but not AMM, diminished the contractions induced by KCl, EFS or ACh. The spasmolytic activity of AMX was partially inhibited by hexamethonium, ganglionic blocker; and indomethacin, inhibitor of the synthesis of prostaglandins; but not by L-NAME, inhibitor of nitric oxide synthase. In addition, AMX diminished the maximal contraction induced by CaCl 2 in a calcium-free medium. Chromatographic analyses of these methanol extracts showed the presence of acacetin and tilanin in both. These results suggest that in folk medicine only AMX should be used as spasmolytic, and not in combination with AMM as traditionally occurs, due to the spasmogenic effects of the latter. In addition, activation of nicotinic receptors, prostaglandins and calcium channels, but

  2. Sand flies naturally infected by Leishmania (L.) mexicana in the peri-urban area of Chetumal city, Quintana Roo, México.

    PubMed

    Sánchez-García, Laura; Berzunza-Cruz, Miriam; Becker-Fauser, Ingeborg; Rebollar-Téllez, Eduardo A

    2010-06-01

    The surveillance of prevalent Leishmania sand fly vectors is an important issue for epidemiological studies in populated areas where leishmaniasis is endemic. In this study, we collected sand flies from a peri-urban area in the southeast of Mexico. Natural infection with Leishmania (L.) mexicana was studied by PCR using a Leishmania internal transcribed spacer of the ribosomal RNA gene for amplification. Infected Lutzomyia olmeca olmeca, Lu. shannoni and Lu. cruciata sand flies were collected mainly during the high transmission season (November to March), coinciding with the highest sand fly densities. Additionally, positive specimens of Lu. olmeca olmeca were also captured during July and August. The infected sand flies were from primary forest (subperennial forest) and secondary forest (18-25 years old and 10-15 years old respectively). Sand flies collected with Disney and Shannon traps were the ones found to be infected with L. (L.) mexicana. We conclude that the high-risk period in which L. (L.) mexicana is transmitted in the peri-urban area of Chetumal City is from July to March and that transmission is associated with both the subperennial forest and the secondary forest. 2010 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

  3. Investigation of adsorption of Rhodamine B onto a natural adsorbent Argemone mexicana.

    PubMed

    Khamparia, Shraddha; Jaspal, Dipika

    2016-12-01

    The present study aims at exploring the potential of the seeds of a tropical weed, Argemone mexicana (AM), for the removal of a toxic xanthene textile dye, Rhodamine B (RHB), from waste water. Impact of pH, adsorbent dosage, particle size, contact time and dye concentration have been assessed during adsorption. The weed has been well characterized by several latest techniques thereby providing an indepth information of the mechanism during adsorption. About 80% removal has been attained with 0.06 g of adsorbent over the studied system. Thermodynamic and kinetic studies, followed by second order kinetic model, directed towards the endothermic nature of adsorption. The results obtained from batch experiments were modelled using Langmuir and Freundlich isotherm and were analysed on the basis of R 2 and six error functions for selection of appropriate model. Langmuir isotherm was found to be best fitted to the experimental data with high values of R 2 and lower values of error functions. Adsorption study revealed the affinity of AM seeds for the dye ions present in waste water, introducing a novel adsorbent in field of waste water treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Contributions of Zea mays subspecies mexicana haplotypes to modern maize.

    PubMed

    Yang, Ning; Xu, Xi-Wen; Wang, Rui-Ru; Peng, Wen-Lei; Cai, Lichun; Song, Jia-Ming; Li, Wenqiang; Luo, Xin; Niu, Luyao; Wang, Yuebin; Jin, Min; Chen, Lu; Luo, Jingyun; Deng, Min; Wang, Long; Pan, Qingchun; Liu, Feng; Jackson, David; Yang, Xiaohong; Chen, Ling-Ling; Yan, Jianbing

    2017-11-30

    Maize was domesticated from lowland teosinte (Zea mays ssp. parviglumis), but the contribution of highland teosinte (Zea mays ssp. mexicana, hereafter mexicana) to modern maize is not clear. Here, two genomes for Mo17 (a modern maize inbred) and mexicana are assembled using a meta-assembly strategy after sequencing of 10 lines derived from a maize-teosinte cross. Comparative analyses reveal a high level of diversity between Mo17, B73, and mexicana, including three Mb-size structural rearrangements. The maize spontaneous mutation rate is estimated to be 2.17 × 10 -8 ~3.87 × 10 -8 per site per generation with a nonrandom distribution across the genome. A higher deleterious mutation rate is observed in the pericentromeric regions, and might be caused by differences in recombination frequency. Over 10% of the maize genome shows evidence of introgression from the mexicana genome, suggesting that mexicana contributed to maize adaptation and improvement. Our data offer a rich resource for constructing the pan-genome of Zea mays and genetic improvement of modern maize varieties.

  5. In vitro activity of Tridax procumbens against promastigotes of Leishmania mexicana.

    PubMed

    Martín-Quintal, Zhelmy; Moo-Puc, Rosa; González-Salazar, Francisco; Chan-Bacab, Manuel J; Torres-Tapia, Luis W; Peraza-Sánchez, Sergio R

    2009-04-21

    Tridax procumbens is an active herb against leishmaniasis. Leishmaniasis is a group of diseases caused by Leishmania protozoa. We investigated the antileishmanial activity of Tridax procumbens extracts and a pure compound against promastigotes of Leishmania mexicana, the causative agent of cutaneous leishmaniasis in the New World. Extracts and (3S)-16,17-didehydrofalcarinol (1) were obtained by chromatographic methods from Tridax procumbens, and the latter identified by spectroscopic analysis. The effect of these extracts and 1 on the growth inhibition of promastigotes of Leishmania mexicana was evaluated. In order to test the safety of extracts and 1, mammalian cells were treated with them, and cell viability was assessed using trypan blue and MTT. We demonstrated that extracts of Tridax procumbens and 1 showed a pronounced activity against Leishmania mexicana. The methanol extract inhibited promastigotes growth of Leishmania mexicana with a 50% inhibitory concentration (IC(50)) of 3 microg/ml, while oxylipin 1 exhibited the highest inhibition at IC(50)=0.478 microg/ml. In this study we report the biological activity of extracts and (3S)-16,17-didehydrofalcarinol (1), obtained from Tridax procumbens, on the promastigote form of Leishmania mexicana, with no effect upon mammalian cells.

  6. What is Sambucus mexicana (Adoxaceae)?

    USDA-ARS?s Scientific Manuscript database

    Inconsistent application of the name Sambucus mexicana Presl ex DC. has resulted in confusion in the literature and in herbaria, so Presl’s original material (a Haenke collection, made on the Malaspina Expedition) was located and characterized. It matches plants from the area around Monterey, Califo...

  7. Leishmaniasis in Texas: Isolation of Leishmania mexicana from Neotoma Micropus

    DTIC Science & Technology

    1990-01-01

    leishmaniasis cases in Texas, 2) Lutzomyia anthophora, a sand fly which has transmitted Leishmania mexicana under laboratory conditions (Endris et al., 1984...Addis, 1945). Other vertebrates such as opossums, hispid cotton rats, and armadillos and other sand flies such as Lutzomyia diabolica and Lutzomyia texana...Leishmania mexicana by a North American sand fly, Lutzomyia anthophora (Diptera: Psychodidae). Journal of Medical Entomology 24: 243- 247. GRIMALDI, G. Jr

  8. Leishmania mexicana Gp63 cDNA Using Gene Gun Induced Higher Immunity to L. mexicana Infection Compared to Soluble Leishmania Antigen in BALB/C

    PubMed Central

    Rezvan, H; Rees, R; Ali, SA

    2011-01-01

    Background Leishmaniasis is a worldwide disease prevalent in tropical and sub tropical countries. Many attempts have been made and different strategies have been approached to develop a potent vaccine against Leishmania. DNA immunisation is a method, which is shown to be effective in Leishmania vaccination. Leishmania Soluble Antigen (SLA) has also recently been used Leishmania vaccination. Methods The immunity generated by SLA and L. mexicana gp63 cDNA was compared in groups of 6 mice, which were statistically analysed by student t- test with the P-value of 0.05. SLA was administered by two different methods; intramuscular injection and injection of dendritic cells (DCs) loaded with SLA. L. mexicana gp63 cDNA was administered by the gene gun. Results Immunisation of BALB/c mice with L. mexicana gp63 resulted in high levels of Th1-type immune response and cytotoxic T lymphocytes (CTL) activity, which were accompanied with protection induced by the immunisation against L. mexicana infection. In contrast, administration of SLA, produced a mixed Th1/Th2-type immune responses as well as a high level of CTL activity but did not protect mice from the infection. Conclusion The results indicate higher protection by DNA immunisation using L. mexicana gp63 cDNA compared to SLA, which is accompanied by a high level of Th1 immune response. However, the CTL activity does not necessarily correlate with the protection induced by the vaccine. Also, gene gun immunisation is a potential approach in Leishmania vaccination. These findings would be helpful in opening new windows in Leishmania vaccine research. PMID:22347315

  9. Recurrence of Mexican long-tongued bats (Choeronycteris mexicana) at historical sites in Arizona and New Mexico

    USGS Publications Warehouse

    Cryan, P.M.; Bogan, M.A.

    2003-01-01

    The Mexican long-tongued bat (Choeronycteris mexicana) is a nectar-eating species that seasonally inhabits the southwestern United States. Since 1906, fewer than 1500 individuals of C. mexicana have been documented throughout the range of the species. We conducted a field survey in Arizona and New Mexico during summer 1999 to check historically occupied areas for recurrence of C. mexicana. We observed C. mexicana occupying a majority (75%, n = 18) of visited sites. Multiple individuals were observed at many sites, including young-of-year. Choeronycteris mexicana roosted in lighted areas close to entrances within mine adits, abandoned buildings, wide rock crevices, and caves. All occupied sites were in Madrean evergreen woodlands or semidesert grasslands where species of Agave were present. Most sites were located near a water source and, with the exception of a single site, near areas of riparian vegetation. Sites at which we did not encounter C. mexicana were frequently disturbed, difficult to search, or historically occupied by single individuals. Based on the relatively high rate of bat recurrence, we do not believe that populations of C. mexicana in the region have declined dramatically over the past several decades.

  10. Leishmania (L.) mexicana Infected Bats in Mexico: Novel Potential Reservoirs

    PubMed Central

    Berzunza-Cruz, Miriam; Rodríguez-Moreno, Ángel; Gutiérrez-Granados, Gabriel; González-Salazar, Constantino; Stephens, Christopher R.; Hidalgo-Mihart, Mircea; Marina, Carlos F.; Rebollar-Téllez, Eduardo A.; Bailón-Martínez, Dulce; Balcells, Cristina Domingo; Ibarra-Cerdeña, Carlos N.; Sánchez-Cordero, Víctor; Becker, Ingeborg

    2015-01-01

    Leishmania (Leishmania) mexicana causes cutaneous leishmaniasis, an endemic zoonosis affecting a growing number of patients in the southeastern states of Mexico. Some foci are found in shade-grown cocoa and coffee plantations, or near perennial forests that provide rich breeding grounds for the sand fly vectors, but also harbor a variety of bat species that live off the abundant fruits provided by these shade-giving trees. The close proximity between sand flies and bats makes their interaction feasible, yet bats infected with Leishmania (L.) mexicana have not been reported. Here we analyzed 420 bats from six states of Mexico that had reported patients with leishmaniasis. Tissues of bats, including skin, heart, liver and/or spleen were screened by PCR for Leishmania (L.) mexicana DNA. We found that 41 bats (9.77%), belonging to 13 species, showed positive PCR results in various tissues. The infected tissues showed no evidence of macroscopic lesions. Of the infected bats, 12 species were frugivorous, insectivorous or nectarivorous, and only one species was sanguivorous (Desmodus rotundus), and most of them belonged to the family Phyllostomidae. The eco-region where most of the infected bats were caught is the Gulf Coastal Plain of Chiapas and Tabasco. Through experimental infections of two Tadarida brasiliensis bats in captivity, we show that this species can harbor viable, infective Leishmania (L.) mexicana parasites that are capable of infecting BALB/c mice. We conclude that various species of bats belonging to the family Phyllostomidae are possible reservoir hosts for Leishmania (L.) mexicana, if it can be shown that such bats are infective for the sand fly vector. Further studies are needed to determine how these bats become infected, how long the parasite remains viable inside these potential hosts and whether they are infective to sand flies to fully evaluate their impact on disease epidemiology. PMID:25629729

  11. Leishmania (L.) mexicana infected bats in Mexico: novel potential reservoirs.

    PubMed

    Berzunza-Cruz, Miriam; Rodríguez-Moreno, Ángel; Gutiérrez-Granados, Gabriel; González-Salazar, Constantino; Stephens, Christopher R; Hidalgo-Mihart, Mircea; Marina, Carlos F; Rebollar-Téllez, Eduardo A; Bailón-Martínez, Dulce; Balcells, Cristina Domingo; Ibarra-Cerdeña, Carlos N; Sánchez-Cordero, Víctor; Becker, Ingeborg

    2015-01-01

    Leishmania (Leishmania) mexicana causes cutaneous leishmaniasis, an endemic zoonosis affecting a growing number of patients in the southeastern states of Mexico. Some foci are found in shade-grown cocoa and coffee plantations, or near perennial forests that provide rich breeding grounds for the sand fly vectors, but also harbor a variety of bat species that live off the abundant fruits provided by these shade-giving trees. The close proximity between sand flies and bats makes their interaction feasible, yet bats infected with Leishmania (L.) mexicana have not been reported. Here we analyzed 420 bats from six states of Mexico that had reported patients with leishmaniasis. Tissues of bats, including skin, heart, liver and/or spleen were screened by PCR for Leishmania (L.) mexicana DNA. We found that 41 bats (9.77%), belonging to 13 species, showed positive PCR results in various tissues. The infected tissues showed no evidence of macroscopic lesions. Of the infected bats, 12 species were frugivorous, insectivorous or nectarivorous, and only one species was sanguivorous (Desmodus rotundus), and most of them belonged to the family Phyllostomidae. The eco-region where most of the infected bats were caught is the Gulf Coastal Plain of Chiapas and Tabasco. Through experimental infections of two Tadarida brasiliensis bats in captivity, we show that this species can harbor viable, infective Leishmania (L.) mexicana parasites that are capable of infecting BALB/c mice. We conclude that various species of bats belonging to the family Phyllostomidae are possible reservoir hosts for Leishmania (L.) mexicana, if it can be shown that such bats are infective for the sand fly vector. Further studies are needed to determine how these bats become infected, how long the parasite remains viable inside these potential hosts and whether they are infective to sand flies to fully evaluate their impact on disease epidemiology.

  12. Mechanism of action of relaxant effect of Agastache mexicana ssp.mexicana essential oil in guinea-pig trachea smooth muscle.

    PubMed

    Navarrete, Andrés; Ávila-Rosas, Natalia; Majín-León, Mateo; Balderas-López, José Luis; Alfaro-Romero, Alejandro; Tavares-Carvalho, José Carlos

    2017-12-01

    Agastache mexicana ssp. mexicana (Kunth) Lint & Epling (Lamiaceae), popularly known as 'toronjil morado', is used in Mexican traditional medicine for the treatment of several diseases such as hypertension, anxiety and respiratory disorders. This study investigates the relaxant action mechanism of A. mexicana ssp. mexicana essential oil (AMEO) in guinea-pig isolated trachea model. AMEO was analyzed by GC/MS. The relaxant effect of AMEO (5-50 μg/mL) was tested in guinea-pig trachea pre-contracted with carbachol (3 × 10  -   6  M) or histamine (3 × 10  -   5  M) in the presence or absence of glibenclamide (10  -   5  M), propranolol (3 × 10  -   6  M) or 2',5'-dideoxyadenosine (10  -   5  M). The antagonist effect of AMEO (10-300 μg/mL) against contractions elicited by carbachol (10  -   15 -10  -   3  M), histamine (10  -   15 -10  -   3  M) or calcium (10-300 μg/mL) was evaluated. Essential oil composition was estragole, d-limonene and linalyl anthranilate. AMEO relaxed the carbachol (EC 50  =   18.25 ± 1.03 μg/mL) and histamine (EC 50  =   13.3 ± 1.02 μg/mL)-induced contractions. The relaxant effect of AMEO was not modified by the presence of propranolol, glibenclamide or 2',5'-dideoxyadenosine, suggesting that effect of AMEO is not related to β 2 -adrenergic receptors, ATP-sensitive potassium channels or adenylate cyclase activation. AMEO was more potent to antagonize histamine (pA 2 ' = -1.507 ± 0.122) than carbachol (pA 2 ' = -2.180 ± 0.357). Also, AMEO antagonized the calcium chloride-induced contractions. The results suggest that relaxant effect of AMEO might be due to blockade of calcium influx in guinea-pig trachea smooth muscle. It is possible that estragole and d-limonene could contribute majority in the relaxant effect of AMEO.

  13. Biodegradation of carbamazepine using freshwater microalgae Chlamydomonas mexicana and Scenedesmus obliquus and the determination of its metabolic fate.

    PubMed

    Xiong, Jiu-Qiang; Kurade, Mayur B; Abou-Shanab, Reda A I; Ji, Min-Kyu; Choi, Jaeyoung; Kim, Jong Oh; Jeon, Byong-Hun

    2016-04-01

    This study evaluated the toxicity and cellular stresses of carbamazepine (CBZ) on Chlamydomonas mexicana and Scenedesmus obliquus, and its biodegradation by both microalgal species. The growth of both microalgal species decreased with increase of CBZ concentration. The growth of S. obliquus was significantly inhibited (97%) at 200 mg CBZ L(-1), as compared to the control after 10days; whereas, C. mexicana showed 30% inhibition at the same experimental conditions. Biochemical characteristics including total chlorophyll, carotenoid contents and enzyme activities (SOD and CAT) for both species were affected by CBZ at relatively high concentration. C. mexicana and S. obliquus could achieve a maximum of 35% and 28% biodegradation of CBZ, respectively. Two metabolites (10,11-dihydro-10,11-expoxycarbamazepine and n-hydroxy-CBZ) were identified by UPLC-MS, as a result of CBZ biodegradation by C. mexicana. This study demonstrated that C. mexicana was more tolerant to CBZ and could be used for treatment of CBZ contaminated wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Photoacoustic monitoring of life cycles of Leishmania Mexicana

    NASA Astrophysics Data System (ADS)

    Arguello, C.; Acosta-Avalos, D.; Alvarado-Gil, J. J.; Vargas, H.

    1999-03-01

    Photoacoustic spectroscopy is used to monitor in situ, the difference between the two forms of the protozoan Leishmania Mexicana. Differences are the result of changes in the respiratory chain and could be attributed, according to our results, to the presence of cytochrome b in promastigotes and cytochrome c in amastigotes.

  15. Diversity among Tacaribe serocomplex viruses (family Arenaviridae) naturally associated with the Mexican woodrat (Neotoma mexicana)

    PubMed Central

    Cajimat, Maria N. B.; Milazzo, Mary Louise; Borchert, Jeff N.; Abbott, Ken D.; Bradley, Robert D.; Fulhorst, Charles F.

    2008-01-01

    The results of analyses of glycoprotein precursor and nucleocapsid protein gene sequences indicated that an arenavirus isolated from a Mexican woodrat (Neotoma mexicana) captured in Arizona is a strain of a novel species (proposed name Skinner Tank virus) and that arenaviruses isolated from Mexican woodrats captured in Colorado, New Mexico, and Utah are strains of Whitewater Arroyo virus or species phylogenetically closely related to Whitewater Arroyo virus. Pairwise comparisons of glycoprotein precursor sequences and nucleocapsid protein sequences revealed a high level of divergence among the viruses isolated from the Mexican woodrats captured in Colorado, New Mexico, and Utah and the Whitewater Arroyo virus prototype strain AV 9310135, which originally was isolated from a white-throated woodrat (Neotoma albigula) captured in New Mexico. Conceptually, the viruses from Colorado, New Mexico, and Utah and strain AV 9310135 could be grouped together in a species complex in the family Arenaviridae, genus Arenavirus. PMID:18304671

  16. Mg/Ca temperature calibration for the benthic foraminifers Bulimina inflata and Bulimina mexicana

    NASA Astrophysics Data System (ADS)

    Grunert, Patrick; Rosenthal, Yair; Jorissen, Frans; Holbourn, Ann

    2016-04-01

    Bulimina inflata Seguenza 1862 and Bulimina mexicana Cushman 1922 are cosmopolitan, shallow infaunal benthic foraminifers which are common in the fossil record throughout the Neogene and Quaternary. The closely related species share a similar costate shell morphology that differs in the presence or absence of an apical spine. In the present study, we evaluate the temperature dependency of Mg/Ca ratios of these species from an extensive set of core-top samples from the Atlantic and Pacific oceans. The results show no significant offset in Mg/Ca values between B. inflata, B. mexicana, and two other costate morphospecies when present in the same sample. The apparent lack of significant inter-specific/inter-morphotype differences amongst the analysed costate buliminds allows for the combined use of their data-sets for our core-top calibration. Over a bottom-water temperature range of 3-14°C, the Bulimina inflata/mexicana group shows a sensitivity of ˜0.12 mmol/mol/°C which is comparable to the epifaunal Cibicidoides pachyderma and higher than for the shallow infaunal Uvigerina spp., the most commonly used taxa in Mg/Ca-based palaeotemperature reconstruction. B. inflata and B. mexicana might thus be a valuable alternative in mesotrophic settings where many of the commonly used species are diminished or absent, and particularly useful in hypoxic settings where costate buliminds may dominate foraminiferal assemblages. This study was financially supported by the Max-Kade-Foundation and contributes to project P25831-N29 of the Austrian Science Fund (FWF).

  17. In vivo and in vitro control of Leishmania mexicana due to garlic-induced NO production.

    PubMed

    Gamboa-León, M R; Aranda-González, I; Mut-Martín, M; García-Miss, M R; Dumonteil, E

    2007-11-01

    Leishmania mexicana is the main causal agent of cutaneous leishmaniasis in the Yucatán peninsula in Mexico. Control of this disease is associated with a Th1-type immune response and garlic extract has been reported as a Th1 immunomodulator in BALB/c mice infected with Leishmania major. In this study, we investigated the effect of garlic extracts on L. mexicana infection in vivo and in vitro. Garlic extract reduced footpad lesions in L. mexicana-infected BALB/c mice by inducing IFN-gamma production from T cells. In vitro, garlic extract reduced macrophage infection through induction of nitric oxide (NO) production. Garlic extract may thus act on both T cells and macrophages to stimulate IFN-gamma production and NO synthesis for parasite killing. A 10- to 14-kDa fraction was identified as responsible for the in vitro effect of the whole extract and may lead to the identification of novel immunomodulating drugs and therapeutic alternatives for the treatment of leishmaniasis.

  18. Prosexual Effect of Chrysactinia mexicana A. Gray (Asteraceae), False Damiana, in a Model of Male Sexual Behavior

    PubMed Central

    Estrada-Reyes, R.; Ferreyra-Cruz, O. A.

    2016-01-01

    Chrysactinia mexicana A. Gray (Asteraceae) and Turnera diffusa Willd (Turneraceae) are employed in traditional medicine as aphrodisiacs; however, there is no scientific evidence supporting the prosexual properties of C. mexicana. The aim of this study was to determine whether an aqueous extract of C. mexicana (Cm) stimulates rat male sexual behavior in the sexual exhaustion paradigm. Sexually exhausted (SExh) male rats were treated with Cm (80, 160, and 320 mg/kg), an aqueous extract of T. diffusa (Td), or yohimbine. The sexual exhaustion state in the control group was characterized by a low percentage of males exhibiting mounts, intromissions, and ejaculations and no males demonstrating mating behavior after ejaculation. Cm (320 mg/kg), Td, or yohimbine significantly increased the proportion of SExh rats that ejaculated and resumed copulation after ejaculation. In males that exhibited reversal of sexual exhaustion, Cm (320 mg/kg) improved sexual performance by reducing the number of intromissions and shrinking ejaculation latency. The effects of treatments on sexual behavior were not related with alterations in general locomotion. In conclusion, the prosexual effects of Cm, as well as those of Td, are established at a central level, which supports the traditional use of C. mexicana for stimulating sexual activity. PMID:27656650

  19. Prosexual Effect of Chrysactinia mexicana A. Gray (Asteraceae), False Damiana, in a Model of Male Sexual Behavior.

    PubMed

    Estrada-Reyes, R; Ferreyra-Cruz, O A; Jiménez-Rubio, G; Hernández-Hernández, O T; Martínez-Mota, L

    Chrysactinia mexicana A. Gray (Asteraceae) and Turnera diffusa Willd (Turneraceae) are employed in traditional medicine as aphrodisiacs; however, there is no scientific evidence supporting the prosexual properties of C. mexicana . The aim of this study was to determine whether an aqueous extract of C. mexicana (Cm) stimulates rat male sexual behavior in the sexual exhaustion paradigm. Sexually exhausted (SExh) male rats were treated with Cm (80, 160, and 320 mg/kg), an aqueous extract of T. diffusa (Td), or yohimbine. The sexual exhaustion state in the control group was characterized by a low percentage of males exhibiting mounts, intromissions, and ejaculations and no males demonstrating mating behavior after ejaculation. Cm (320 mg/kg), Td, or yohimbine significantly increased the proportion of SExh rats that ejaculated and resumed copulation after ejaculation. In males that exhibited reversal of sexual exhaustion, Cm (320 mg/kg) improved sexual performance by reducing the number of intromissions and shrinking ejaculation latency. The effects of treatments on sexual behavior were not related with alterations in general locomotion. In conclusion, the prosexual effects of Cm, as well as those of Td, are established at a central level, which supports the traditional use of C. mexicana for stimulating sexual activity.

  20. Spectroscopic study of antileishmanial drug incubated in the promastigotes of Leishmania mexicana

    NASA Astrophysics Data System (ADS)

    Hung, J.; Castillo, J.; Jiménez, G.; Hasegawa, M.; Rodriguez, M.

    2003-11-01

    In this work we present spectroscopic study of Boldine (aporphine alkaloid) that possesses important biological activities, in particular, in interaction with the promastigotes of Leishmania mexicana. The results show the applicability of autofluorescence of this drug to determinate the possible mechanism of its biological action. The blue shift and hyperchromic effect in the emission spectrum of the drug in interaction with the parasite cells indicate an energy transference process between them. The morphological change of cell shape of the promastigotes treated with the drug is observed using confocal microscopy. This morphological cell-shape transformation evidences an important interaction between the drug studied and some protein of the parasite cell. Here we describe for the first time the fluorescence properties of the Boldine in the promastigotes of L. mexicana.

  1. Complementary effect of natural and sexual selection against immigrants maintains differentiation between locally adapted fish

    NASA Astrophysics Data System (ADS)

    Plath, Martin; Riesch, Rüdiger; Oranth, Alexandra; Dzienko, Justina; Karau, Nora; Schießl, Angela; Stadler, Stefan; Wigh, Adriana; Zimmer, Claudia; Arias-Rodriguez, Lenin; Schlupp, Ingo; Tobler, Michael

    2010-08-01

    Adaptation to ecologically heterogeneous environments can drive speciation. But what mechanisms maintain reproductive isolation among locally adapted populations? Using poeciliid fishes in a system with naturally occurring toxic hydrogen sulfide, we show that (a) fish from non-sulfidic sites ( Poecilia mexicana) show high mortality (95 %) after 24 h when exposed to the toxicant, while locally adapted fish from sulfidic sites ( Poecilia sulphuraria) experience low mortality (13 %) when transferred to non-sulfidic water. (b) Mate choice tests revealed that P. mexicana females exhibit a preference for conspecific males in non-sulfidic water, but not in sulfidic water, whereas P. sulphuraria females never showed a preference. Increased costs of mate choice in sulfidic, hypoxic water, and the lack of selection for reinforcement due to the low survival of P. mexicana may explain the absence of a preference in P. sulphuraria females. Taken together, our study may be the first to demonstrate independent—but complementary—effects of natural and sexual selection against immigrants maintaining differentiation between locally adapted fish populations.

  2. Complementary effect of natural and sexual selection against immigrants maintains differentiation between locally adapted fish.

    PubMed

    Plath, Martin; Riesch, Rüdiger; Oranth, Alexandra; Dzienko, Justina; Karau, Nora; Schiessl, Angela; Stadler, Stefan; Wigh, Adriana; Zimmer, Claudia; Arias-Rodriguez, Lenin; Schlupp, Ingo; Tobler, Michael

    2010-08-01

    Adaptation to ecologically heterogeneous environments can drive speciation. But what mechanisms maintain reproductive isolation among locally adapted populations? Using poeciliid fishes in a system with naturally occurring toxic hydrogen sulfide, we show that (a) fish from non-sulfidic sites (Poecilia mexicana) show high mortality (95 %) after 24 h when exposed to the toxicant, while locally adapted fish from sulfidic sites (Poecilia sulphuraria) experience low mortality (13 %) when transferred to non-sulfidic water. (b) Mate choice tests revealed that P. mexicana females exhibit a preference for conspecific males in non-sulfidic water, but not in sulfidic water, whereas P. sulphuraria females never showed a preference. Increased costs of mate choice in sulfidic, hypoxic water, and the lack of selection for reinforcement due to the low survival of P. mexicana may explain the absence of a preference in P. sulphuraria females. Taken together, our study may be the first to demonstrate independent-but complementary-effects of natural and sexual selection against immigrants maintaining differentiation between locally adapted fish populations.

  3. Temperature-Induced Protein Secretion by Leishmania mexicana Modulates Macrophage Signalling and Function

    PubMed Central

    Hassani, Kasra; Antoniak, Elisabeth; Jardim, Armando; Olivier, Martin

    2011-01-01

    Protozoan parasites of genus Leishmania are the causative agents of leishmaniasis. These digenetic microorganisms undergo a marked environmental temperature shift (TS) during transmission from the sandfly vector (ambient temperature, 25–26°C) to the mammalian host (37°C). We have observed that this TS induces a rapid and dramatic increase in protein release from Leishmania mexicana (cutaneous leishmaniasis) within 4 h. Proteomic identification of the TS-induced secreted proteins revealed 72 proteins, the majority of which lack a signal peptide and are thus thought to be secreted via nonconventional mechanisms. Interestingly, this protein release is accompanied by alterations in parasite morphology including an augmentation in the budding of exovesicles from its surface. Here we show that the exoproteome of L. mexicana upon TS induces cleavage and activation of the host protein tyrosine phosphatases, specifically SHP-1 and PTP1-B, in a murine bone-marrow-derived macrophage cell line. Furthermore, translocation of prominent inflammatory transcription factors, namely NF-κB and AP-1 is altered. The exoproteome also caused inhibition of nitric oxide production, a crucial leishmanicidal function of the macrophage. Overall, our results provide strong evidence that within early moments of interaction with the mammalian host, L. mexicana rapidly releases proteins and exovesicles that modulate signalling and function of the macrophage. These modulations can result in attenuation of the inflammatory response and deactivation of the macrophage aiding the parasite in the establishment of infection. PMID:21559274

  4. Association of Lutzomyia columbiana (Diptera: Psychodidae) with a leishmaniasis focus in Colombia due to species of the Leishmania mexicana complex.

    PubMed

    Montoya-Lerma, J; Cadena, H; Segura, I; Travi, B L

    1999-01-01

    In Colombia, Leishmania mexicana has a scattered geographical distribution and no sand fly vectors have been associated with its transmission. During the present study, the anthropophilic sand fly Lutzomyia columbiana was found to be the only species collected using diverse methods, in a small focus of Le. mexicana in the municipality of Samaniego, SW Colombia. Ecological data indicate that this sand fly species is present in both peri and intradomestic habitats, where it readily bites man. Further evidence comes from experimental infections of wild-caught Lu. columbiana with Le. mexicana after feeding on infected hamsters. Based on these results, it is suggested that this sand fly is the most likely vector in the study area, suggesting the existence of a previously unknown sand fly-parasite association.

  5. Ovarian structure and oogenesis of the extremophile viviparous teleost Poecilia mexicana (Poeciliidae) from an active sulfur spring cave in Southern Mexico.

    PubMed

    Torres-Martínez, Aarón; Hernández-Franyutti, Arlette; Uribe, Mari Carmen; Contreras-Sánchez, Wilfrido Miguel

    2017-12-01

    The structure of the ovary and oogenesis of Poecilia mexicana from an active sulfur spring cave is documented. Poecilia mexicana is the only poeciliid adapted to a subterranean environment with high hydrogen sulfide levels and extreme hypoxic conditions. Twenty females were captured throughout one year at Cueva del Azufre, located in the State of Tabasco in Southern Mexico. Ovaries were processed with histological techniques. P. mexicana has a single, ovoid ovary with ovigerous lamella that project to the ovarian lumen. The ovarian wall presents abundant loose connective tissue, numerous melanomacrophage centers and large blood vessels, possibly associated with hypoxic conditions. The germinal epithelium bordering the ovarian lumen contains somatic and germ cells forming cell nests projecting into the stroma. P. mexicana stores sperm in ovarian folds associated with follicles at different developmental phases. Oogenesis in P. mexicana consisted of the following stages: (i) oogonial proliferation, (ii) chromatin nucleolus, (iii) primary growth, subdivided into: (a) one nucleolus, (b) multiple nucleoli, (c) droplet oils-cortical alveoli steps; (iv) secondary growth, subdivided in: (a) early secondary growth, (b) late secondary growth, and (c) full grown. Follicular atresia was present in all stages of follicular development; it was characterized by oocyte degeneration, where follicle cells hypertrophy and differentiate in phagocytes. The ovary and oogenesis are similar to these seen in other poeciliids, but we found frequent atretic follicles, melanomacrophage centers, reduced fecundity and increased of offspring size. © 2017 Wiley Periodicals, Inc.

  6. Reverse pharmacology for developing an anti-malarial phytomedicine. The example of Argemone mexicana

    PubMed Central

    Simoes-Pires, Claudia; Hostettmann, Kurt; Haouala, Amina; Cuendet, Muriel; Falquet, Jacques; Graz, Bertrand; Christen, Philippe

    2014-01-01

    Classical pharmacology has been the basis for the discovery of new chemical entities with therapeutic effects for decades. In natural product research, compounds are generally tested in vivo only after full in vitro characterization. However drug screening using this methodology is expensive, time-consuming and very often inefficient. Reverse pharmacology, also called bedside-to-bench, is a research approach based on the traditional knowledge and relates to reversing the classical laboratory to clinic pathway to a clinic to laboratory practice. It is a trans-disciplinary approach focused on traditional knowledge, experimental observations and clinical experiences. This paper is an overview of the reverse pharmacology approach applied to the decoction of Argemone mexicana, used as an antimalarial traditional medicine in Mali. A. mexicana appeared as the most effective traditional medicine for the treatment of uncomplicated falciparum malaria in Mali, and the clinical efficacy of the decoction was comparable to artesunate–amodiaquine as previously published. Four stages of the reverse pharmacology process will be described here with a special emphasis on the results for stage 4. Briefly, allocryptopine, protopine and berberine were isolated through bioguided fractionation, and had their identity confirmed by spectroscopic analysis. The three alkaloids showed antiparasitic activity in vitro, of which allocryptopine and protopine were selective towards Plasmodiumfalciparum. Furthermore, the amount of the three active alkaloids in the decoction was determined by quantitative NMR, and preliminary in vivo assays were conducted. On the basis of these results, the reverse pharmacology approach is discussed and further pharmacokinetic studies appear to be necessary in order to determine whether these alkaloids can be considered as phytochemical markers for quality control and standardization of an improved traditional medicine made with this plant. PMID:25516845

  7. Reverse pharmacology for developing an anti-malarial phytomedicine. The example of Argemone mexicana.

    PubMed

    Simoes-Pires, Claudia; Hostettmann, Kurt; Haouala, Amina; Cuendet, Muriel; Falquet, Jacques; Graz, Bertrand; Christen, Philippe

    2014-12-01

    Classical pharmacology has been the basis for the discovery of new chemical entities with therapeutic effects for decades. In natural product research, compounds are generally tested in vivo only after full in vitro characterization. However drug screening using this methodology is expensive, time-consuming and very often inefficient. Reverse pharmacology, also called bedside-to-bench, is a research approach based on the traditional knowledge and relates to reversing the classical laboratory to clinic pathway to a clinic to laboratory practice. It is a trans-disciplinary approach focused on traditional knowledge, experimental observations and clinical experiences. This paper is an overview of the reverse pharmacology approach applied to the decoction of Argemone mexicana, used as an antimalarial traditional medicine in Mali. A. mexicana appeared as the most effective traditional medicine for the treatment of uncomplicated falciparum malaria in Mali, and the clinical efficacy of the decoction was comparable to artesunate-amodiaquine as previously published. Four stages of the reverse pharmacology process will be described here with a special emphasis on the results for stage 4. Briefly, allocryptopine, protopine and berberine were isolated through bioguided fractionation, and had their identity confirmed by spectroscopic analysis. The three alkaloids showed antiparasitic activity in vitro, of which allocryptopine and protopine were selective towards Plasmodium falciparum. Furthermore, the amount of the three active alkaloids in the decoction was determined by quantitative NMR, and preliminary in vivo assays were conducted. On the basis of these results, the reverse pharmacology approach is discussed and further pharmacokinetic studies appear to be necessary in order to determine whether these alkaloids can be considered as phytochemical markers for quality control and standardization of an improved traditional medicine made with this plant.

  8. Germacranolide-type sesquiterpene lactones from Smallanthus sonchifolius with promising activity against Leishmania mexicana and Trypanosoma cruzi.

    PubMed

    Ulloa, Jerónimo L; Spina, Renata; Casasco, Agustina; Petray, Patricia B; Martino, Virginia; Sosa, Miguel A; Frank, Fernanda M; Muschietti, Liliana V

    2017-11-13

    Leishmaniasis and Chagas disease are life-threatening illnesses caused by the protozoan parasites Leishmania spp. and Trypanosoma cruzi, respectively. They are known as "neglected diseases" due to the lack of effective drug treatments and the scarcity of research work devoted to them. Therefore, the development of novel and effective drugs is an important and urgent need. Natural products are an important source of bioactive molecules for the development of new drugs. In this study, we evaluated the activity of enhydrin, uvedalin and polymatin B, three sesquiterpene lactones (STLs) isolated from Smallanthus sonchifolius, on Leishmania mexicana (MNYC/BZ/62/M) and Trypanosoma cruzi (Dm28c). In addition, the in vivo trypanocidal activity of enhydrin and uvedalin and the effects of these STLs on parasites' ultrastructure were evaluated. The inhibitory effect of the three STLs on the growth of L. mexicana amastigotes and promastigotes as well as T. cruzi epimastigotes was evaluated in vitro. The changes produced by the STLs on the ultrastructure of parasites were examined by transmission electron microscopy (TEM). Enhydrin and uvedalin were also studied in a murine model of acute T. cruzi infection (RA strain). Serum activities of the hepatic enzymes alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase were used as biochemical markers of hepatotoxicity. The three compounds exhibited leishmanicidal activity on both parasite forms with IC 50 values of 0.42-0.54 μg/ml for promastigotes and 0.85-1.64 μg/ml for intracellular amastigotes. Similar results were observed on T. cruzi epimastigotes (IC 50 0.35-0.60 μg/ml). The TEM evaluation showed marked ultrastructural alterations, such as an intense vacuolization and mitochondrial swelling in both L. mexicana promastigotes and T. cruzi epimastigotes exposed to the STLs. In the in vivo study, enhydrin and uvedalin displayed a significant decrease in circulating parasites (50-71%) and no signs of

  9. [Cutaneous leishmaniasis caused by Leishmania mexicana in Durango, Mexico: first clinical case report].

    PubMed

    Pérez-Vega, Jorge Humberto; López-Moreno, Carmina Yanett; López-Valenzuela, José Angel; Rendón-Maldonado, José Guadalupe; López-Moreno, Héctor Samuel

    2009-01-01

    Leishmanisis is a parasitic diseases caused by intracellular protozoan of Leishmania genus. These parasites are transmitted by the bite of phlebotomine flies. Leishmanises are classified in different clinic variants: cutaneous localized or diffuse, mucocutaneous and visceral. In Mexico, the leishmanisis are distributed in several states, however Durango was considered free of leishmaniasis. A 9 year old male patient with an ulcerated pruriginous node of circular shape, 13 x 18 mm diameter, localized in the back of the right arm with 6 months progression. The patient was a permanent resident of Durango, Mexico. Histopathology evidenced macrophages infected with amastigotes. The PCR-RFLP result was consistent with Leishmania mexicana. Treatment with glucantime was satisfactory. Here we report the first clinical case of leishmanisis cutaneous localized caused by Leishmania mexicana from Durango, Mexico in a 9 years old male, confirming the increasing propagation of this protozoan parasite in Mexico.

  10. Effects of extreme habitat conditions on otolith morphology: a case study on extremophile live bearing fishes (Poecilia mexicana, P. sulphuraria).

    PubMed

    Schulz-Mirbach, Tanja; Riesch, Rüdiger; García de León, Francisco J; Plath, Martin

    2011-12-01

    Our study was designed to evaluate if, and to what extent, restrictive environmental conditions affect otolith morphology. As a model, we chose two extremophile livebearing fishes: (i) Poecilia mexicana, a widespread species in various Mexican freshwater habitats, with locally adapted populations thriving in habitats characterized by the presence of one (or both) of the natural stressors hydrogen sulphide and darkness, and (ii) the closely related Poecilia sulphuraria living in a highly sulphidic habitat (Baños del Azufre). All three otolith types (lapilli, sagittae, and asterisci) of P. mexicana showed a decrease in size ranging from the non-sulphidic cave habitat (Cueva Luna Azufre), to non-sulphidic surface habitats, to the sulphidic cave (Cueva del Azufre), to sulphidic surface habitats (El Azufre), to P. sulphuraria. Although we found a distinct differentiation between ecotypes with respect to their otolith morphology, no clear-cut pattern of trait evolution along the two ecological gradients was discernible. Otoliths from extremophiles captured in the wild revealed only slight similarities to aberrant otoliths found in captive-bred fish. We therefore hypothesize that extremophile fishes have developed coping mechanisms enabling them to avoid aberrant otolith growth - an otherwise common phenomenon in fishes reared under stressful conditions. Copyright © 2011 Elsevier GmbH. All rights reserved.

  11. Evaluation of in vitro aldose reductase inhibitory potential of alkaloidal fractions of Piper nigrum, Murraya koenigii, Argemone mexicana, and Nelumbo nucifera.

    PubMed

    Gupta, Sakshi; Singh, Nirmal; Jaggi, Amteshwar Singh

    2014-05-01

    Aldose reductase is primarily involved in development of long-term diabetic complications due to increased polyol pathway activity. The synthetic aldose reductase inhibitors are not very successful clinically. Therefore, the natural sources may be exploited for safer and effective aldose reductase inhibitors. In the present study, the aldose reductase inhibitory potential of hydroalcoholic and alkaloidal extracts of Piper nigrum, Murraya koenigii, Argemone mexicana, and Nelumbo nucifera was evaluated. The hydroalcoholic and alkaloidal extracts of the selected plants were prepared. The different concentrations of hydroalcoholic and alkaloidal extracts of these plants were evaluated for their goat lens aldose reductase inhibitory activity using dl-glyceraldehyde as substrate. The aldose reductase inhibitory potential of extracts was assessed in terms of their IC50 value. Amongst the hydroalcoholic extracts, the highest aldose reductase inhibitory activity was shown by P. nigrum (IC50 value 35.64±2.7 μg/mL) followed by M. koenigii (IC50 value 45.67±2.57 μg/mL), A. mexicana (IC50 value 56.66±1.30 μg/mL), and N. nucifera (IC50 value 59.78±1.32 μg/mL). Among the alkaloidal extracts, highest inhibitory activity was shown by A. mexicana (IC50 value 25.67±1.25 μg/mL), followed by N. nucifera (IC50 value 28.82±1.85 μg/mL), P. nigrum (IC50 value 30.21±1.63 μg/mL), and M. koenigii (IC50 value 35.66±1.64 μg/mL). It may be concluded that the alkaloidal extracts of these plants possess potent aldose reductase inhibitory activity and may be therapeutically exploited in diabetes-related complications associated with increased activity of aldose reductase.

  12. Associations Between Macroinvertebrates and Paralemanea mexicana, an Endemic Freshwater Red Alga from a Mountain River in Central Mexico.

    PubMed

    Caro-Borrero, A; Carmona-Jiménez, J

    2016-12-01

    Macrophytes are common inhabitants of lotic environments and, depending on their morphological traits, possess adaptations that provide shelter to aquatic invertebrates against strong river flow and predators. They may also be used as a food source by macroinvertebrates. The main goal of this study was to determine the relationship between the red alga Paralemanea mexicana and its role as a shelter and/or food source for lotic macroinvertebrates. We also conducted research on the role of microhabitat and morphological variations of the alga in determining macroinvertebrate taxon abundance, diversity, and functional group composition in a high-current velocity river. Results showed that changes in cover and morphology of P. mexicana were mostly correlated with river current velocity, irradiance, and seasonal variation. In turn, these were related to changes in abundance and diversity of the associated macroinvertebrate community. In addition, six macroinvertebrate functional feeding groups were evaluated for associations with the red alga: filtering and gathering collectors, piercers, scrapers, herbivore shredders, and predators. The results showed that the Trichoptera Hydroptilidae genera Ochrotrichia and Metrichia use P. mexicana as a food source and case-building material. The Trichoptera Glossosomatidae Mortoniella uses the alga as a substrate. The biotic interactions between P. mexicana and associated macroinvertebrates reveal the importance of macrophytes as purveyors of substrate, as food and shelter for macroinvertebrates, and also as promoters of macroinvertebrate community diversity. In addition, it was shown that macroinvertebrate herbivory likely facilitates vegetative propagation of the red alga through increased release and germination of carpospores and new gametophytes.

  13. The california poppy (eschscholtzia mexicana) as a copper indicator plant - a new example

    USGS Publications Warehouse

    Chaffee, M.A.; Gale, C.W.

    1976-01-01

    The abundance and distribution of the California poppy (Eschscholtzia mexicana) correlates closely with the copper-rich outcrop of a small porphyry-type deposit in Arizona. Chemical factors are probably more important than physical factors in determining why this species is sometimes found as a copper indicator plant. ?? 1976.

  14. Seeking a "Mexicana"/"Mestiza" Ethic of Care: Rosa's "Revolución" of Carrying Alongside

    ERIC Educational Resources Information Center

    Sosa-Provencio, Mia Angélica

    2017-01-01

    This Chicana Critical Feminist "Testimonio" reveals a Mexican/Mexican-American Ethic of Care particular to the needs and strengths of "Mexicana/o" students and "Testimonios" of struggle, survival informing one Mexican/Mexican-American female educator of predominantly Mexican/Mexican-American students. This work,…

  15. RNA-seq Analysis of Cold and Drought Responsive Transcriptomes of Zea mays ssp. mexicana L.

    PubMed

    Lu, Xiang; Zhou, Xuan; Cao, Yu; Zhou, Meixue; McNeil, David; Liang, Shan; Yang, Chengwei

    2017-01-01

    The annual Zea mays ssp. mexicana L. is a member of teosinte, a wild relative of the Zea mays spp. mays L. This subspecies has strong growth and regeneration ability, high tiller numbers, high protein and lysine content as well as resistance to many fungal diseases, and it can be effectively used in maize improvement. In this study, we reported a Zea mays ssp. mexicana L. transcriptome by merging data from untreated control (CK), cold (4°C) and drought (PEG2000, 20%) treated plant samples. A total of 251,145 transcripts (N50 = 1,269 bp) and 184,280 unigenes (N50 = 923 bp) were predicted, which code for homologs of near 47% of the published maize proteome. Under cold conditions, 2,232 and 817 genes were up-regulated and down-regulated, respectively, while fewer genes were up-regulated (532) and down-regulated (82) under drought stress, indicating that Zea mays ssp. mexicana L. is more sensitive to the applied cold rather than to the applied drought stresses. Functional enrichment analyses identified many common or specific biological processes and gene sets in response to drought and cold stresses. The ABA dependent pathway, trehalose synthetic pathway and the ICE1-CBF pathway were up-regulated by both stresses. GA associated genes have been shown to differentially regulate the responses to cold in close subspecies in Zea mays . These findings and the identified functional genes can provide useful clues for improving abiotic stress tolerance of maize.

  16. RNA-seq Analysis of Cold and Drought Responsive Transcriptomes of Zea mays ssp. mexicana L.

    PubMed Central

    Lu, Xiang; Zhou, Xuan; Cao, Yu; Zhou, Meixue; McNeil, David; Liang, Shan; Yang, Chengwei

    2017-01-01

    The annual Zea mays ssp. mexicana L. is a member of teosinte, a wild relative of the Zea mays spp. mays L. This subspecies has strong growth and regeneration ability, high tiller numbers, high protein and lysine content as well as resistance to many fungal diseases, and it can be effectively used in maize improvement. In this study, we reported a Zea mays ssp. mexicana L. transcriptome by merging data from untreated control (CK), cold (4°C) and drought (PEG2000, 20%) treated plant samples. A total of 251,145 transcripts (N50 = 1,269 bp) and 184,280 unigenes (N50 = 923 bp) were predicted, which code for homologs of near 47% of the published maize proteome. Under cold conditions, 2,232 and 817 genes were up-regulated and down-regulated, respectively, while fewer genes were up-regulated (532) and down-regulated (82) under drought stress, indicating that Zea mays ssp. mexicana L. is more sensitive to the applied cold rather than to the applied drought stresses. Functional enrichment analyses identified many common or specific biological processes and gene sets in response to drought and cold stresses. The ABA dependent pathway, trehalose synthetic pathway and the ICE1-CBF pathway were up-regulated by both stresses. GA associated genes have been shown to differentially regulate the responses to cold in close subspecies in Zea mays. These findings and the identified functional genes can provide useful clues for improving abiotic stress tolerance of maize. PMID:28223998

  17. Organochlorine Pesticides in Honey and Pollen Samples from Managed Colonies of the Honey Bee Apis mellifera Linnaeus and the Stingless Bee Scaptotrigona mexicana Guérin from Southern, Mexico.

    PubMed

    Ruiz-Toledo, Jovani; Vandame, Rémy; Castro-Chan, Ricardo Alberto; Penilla-Navarro, Rosa Patricia; Gómez, Jaime; Sánchez, Daniel

    2018-05-10

    In this paper, we show the results of investigating the presence of organochlorine pesticides in honey and pollen samples from managed colonies of the honey bee, Apis mellifera L. and of the stingless bee Scaptotrigona mexicana Guérin. Three colonies of each species were moved into each of two sites. Three samples of pollen and three samples of honey were collected from each colony: the first collection occurred at the beginning of the study and the following ones at every six months during a year. Thus the total number of samples collected was 36 for honey (18 for A. mellifera and 18 for S. mexicana ) and 36 for pollen (18 for A. mellifera and 18 for S. mexicana ). We found that 88.44% and 93.33% of honey samples, and 22.22% and 100% of pollen samples of S. mexicana and A. mellifera , respectively, resulted positive to at least one organochlorine. The most abundant pesticides were Heptaclor (44% of the samples), γ-HCH (36%), DDT (19%), Endrin (18%) and DDE (11%). Despite the short foraging range of S. mexicana , the number of pesticides quantified in the honey samples was similar to that of A. mellifera . Paradoxically we found a small number of organochlorines in pollen samples of S. mexicana in comparison to A. mellifera , perhaps indicating a low abundance of pollen sources within the foraging range of this species.

  18. In vitro antifungal activity of coumarin extracted from Loeselia mexicana Brand.

    PubMed

    Navarro-García, Victor M; Rojas, Gabriela; Avilés, Margarita; Fuentes, Macrina; Zepeda, Gerardo

    2011-09-01

    The bis-coumarin daphnoretin and its monomeric precursors scopoletin and umbelliferone were isolated for the first time from the aerial part of Loeselia mexicana Brand (a vegetal species used in Mexican traditional medicine) using chromatographic techniques. The structures of these compounds were determined by (1) H and (13) C NMR analyses. These coumarins were evaluated for in vitro antifungal activity. The three compounds tested showed significant antifungal activity. © 2011 Blackwell Verlag GmbH.

  19. Effect of Argemone mexicana active principles on inhibiting viral multiplication and stimulating immune system in Pacific white leg shrimp Litopenaeus vannamei against white spot syndrome virus.

    PubMed

    Palanikumar, Pandi; Daffni Benitta, Dani Joel; Lelin, Chinnadurai; Thirumalaikumar, Eswaramoorthy; Michaelbabu, Mariavincent; Citarasu, Thavasimuthu

    2018-04-01

    Argemone mexicana called as Mexican prickly poppy is a species of poppy found in Mexico and now widely naturalized in many parts of the world with broad range of bioactivities including anthelmintic, cures lepsory, skin-diseases, inflammations and bilious fevers. Plant parts of A. mexicana were serially extracted with hexane, ethyl acetate, methanol and performed antiviral and immunostimulant screening against WSSV and Vibrio harveyi respectively. The control groups succumbed to death 100% within three days, whereas the mortality was significantly (P < 0.5) reduced to 17.43 and 7.11 in the ethyl acetate extracts of stem and root treated shrimp group respectively. The same trend was reflected in the immunostimulant screening also. Different diets were prepared by the concentrations of 100 (AD-1), 200 (AD-2), 300 (AD-3) and 400 (AD-4) mg kg -1 using A. mexicana stem and root ethyl acetate extracts and fed to Pacific white leg shrimp Litopenaeus vannamei weighed about 9.0 ± 0.5 g for 30 days. The control groups fed with the normal diets devoid of A. mexicana extracts. The antiviral screening results revealed that, the ethyl acetate extract of the stem and root were effectively suppressed the WSSV and it reflected in the lowest cumulative mortality of treated shrimps. After termination of feeding trials, group of shrimps from control and each experimental group were challenged with virulent WSSV by intramuscular (IM) injection and studied cumulative mortality, molecular diagnosis by quantitative real time PCR (qRT-PCR), biochemical, haematological and immunological parameters. Control group succumbed to 100% death within four days, whereas the survival was significantly (P < 0.001) increased to 30, 45, 75 and 79% in AD1, AD-2, AD-4 and AD-5 diets fed shrimp groups respectively. qRT PCR results with positive correlation analysis revealed that, the WSSV copies were gradually decreased when increasing the A. mexicana extracts in the diets. The highest

  20. Complexities of gene expression patterns in natural populations of an extremophile fish (Poecilia mexicana, Poeciliidae)

    PubMed Central

    Passow, Courtney N.; Brown, Anthony P.; Arias-Rodriguez, Lenin; Yee, Muh-Ching; Sockell, Alexandra; Schartl, Manfred; Warren, Wesley C.; Bustamante, Carlos; Kelley, Joanna L.; Tobler, Michael

    2017-01-01

    Variation in gene expression can provide insights into organismal responses to environmental stress and physiological mechanisms mediating adaptation to habitats with contrasting environmental conditions. We performed an RNA-sequencing experiment to quantify gene expression patterns in fish adapted to habitats with different combinations of environmental stressors, including the presence of toxic hydrogen sulphide (H2S) and the absence of light in caves. We specifically asked how gene expression varies among populations living in different habitats, whether population differences were consistent among organs, and whether there is evidence for shared expression responses in populations exposed to the same stressors. We analysed organ-specific transcriptome-wide data from four ecotypes of Poecilia mexicana (nonsulphidic surface, sulphidic surface, nonsulphidic cave and sulphidic cave). The majority of variation in gene expression was correlated with organ type, and the presence of specific environmental stressors elicited unique expression differences among organs. Shared patterns of gene expression between populations exposed to the same environmental stressors increased with levels of organismal organization (from transcript to gene to physiological pathway). In addition, shared patterns of gene expression were more common between populations from sulphidic than populations from cave habitats, potentially indicating that physiochemical stressors with clear biochemical consequences can constrain the diversity of adaptive solutions that mitigate their adverse effects. Overall, our analyses provided insights into transcriptional variation in a unique system, in which adaptation to H2S and darkness coincide. Functional annotations of differentially expressed genes provide a springboard for investigating physiological mechanisms putatively underlying adaptation to extreme environments. PMID:28598519

  1. Gluconeogenesis in Leishmania mexicana

    PubMed Central

    Rodriguez-Contreras, Dayana; Hamilton, Nicklas

    2014-01-01

    Gluconeogenesis is an active pathway in Leishmania amastigotes and is essential for their survival within the mammalian cells. However, our knowledge about this pathway in trypanosomatids is very limited. We investigated the role of glycerol kinase (GK), phosphoenolpyruvate carboxykinase (PEPCK), and pyruvate phosphate dikinase (PPDK) in gluconeogenesis by generating the respective Leishmania mexicana Δgk, Δpepck, and Δppdk null mutants. Our results demonstrated that indeed GK, PEPCK, and PPDK are key players in the gluconeogenesis pathway in Leishmania, although stage-specific differences in their contribution to this pathway were found. GK participates in the entry of glycerol in promastigotes and amastigotes; PEPCK participates in the entry of aspartate in promastigotes, and PPDK is involved in the entry of alanine in amastigotes. Furthermore, the majority of alanine enters into the pathway via decarboxylation of pyruvate in promastigotes, whereas pathway redundancy is suggested for the entry of aspartate in amastigotes. Interestingly, we also found that l-lactate, an abundant glucogenic precursor in mammals, was used by Leishmania amastigotes to synthesize mannogen, entering the pathway through PPDK. On the basis of these new results, we propose a revision in the current model of gluconeogenesis in Leishmania, emphasizing the differences between amastigotes and promastigotes. This work underlines the importance of studying the trypanosomatid intracellular life cycle stages to gain a better understanding of the pathologies caused in humans. PMID:25288791

  2. Disease Severity in Patients Infected with Leishmania mexicana Relates to IL-1β

    PubMed Central

    Fernández-Figueroa, Edith A.; Rangel-Escareño, Claudia; Espinosa-Mateos, Valeria; Carrillo-Sánchez, Karol; Salaiza-Suazo, Norma; Carrada-Figueroa, Georgina; March-Mifsut, Santiago; Becker, Ingeborg

    2012-01-01

    Leishmania mexicana can cause both localized (LCL) and diffuse (DCL) cutaneous leishmaniasis, yet little is known about factors regulating disease severity in these patients. We analyzed if the disease was associated with single nucleotide polymorphisms (SNPs) in IL-1β (−511), CXCL8 (−251) and/or the inhibitor IL-1RA (+2018) in 58 Mexican mestizo patients with LCL, 6 with DCL and 123 control cases. Additionally, we analyzed the in vitro production of IL-1β by monocytes, the expression of this cytokine in sera of these patients, as well as the tissue distribution of IL-1β and the number of parasites in lesions of LCL and DCL patients. Our results show a significant difference in the distribution of IL-1β (−511 C/T) genotypes between patients and controls (heterozygous OR), with respect to the reference group CC, which was estimated with a value of 3.23, 95% CI = (1.2, 8.7) and p-value = 0.0167), indicating that IL-1β (−511 C/T) represents a variable influencing the risk to develop the disease in patients infected with Leishmania mexicana. Additionally, an increased in vitro production of IL-1β by monocytes and an increased serum expression of the cytokine correlated with the severity of the disease, since it was significantly higher in DCL patients heavily infected with Leishmania mexicana. The distribution of IL-1β in lesions also varied according to the number of parasites harbored in the tissues: in heavily infected LCL patients and in all DCL patients, the cytokine was scattered diffusely throughout the lesion. In contrast, in LCL patients with lower numbers of parasites in the lesions, IL-1β was confined to the cells. These data suggest that IL-1β possibly is a key player determining the severity of the disease in DCL patients. The analysis of polymorphisms in CXCL8 and IL-1RA showed no differences between patients with different disease severities or between patients and controls. PMID:22629474

  3. Past, Present and Future: Forty Years of Revista Mexicana de Astronomia y Astrofisica

    NASA Astrophysics Data System (ADS)

    Allen, Christine; Torres-Peimbert, Silvia

    2015-08-01

    We cast a retrospective view on 40 years of publishing the Revista Mexicana de Astronomía y Astrofísica, founded in 1974. The journal is peer-reviewed, has appeared regularly since its foundation, and continues to attract original research papers, mostly by Mexican and Latin American authors. We share some musings about the future of our journal, in view of recent developments in the scientific publishing field.

  4. Inner ear morphology in the Atlantic molly Poecilia mexicana--first detailed microanatomical study of the inner ear of a cyprinodontiform species.

    PubMed

    Schulz-Mirbach, Tanja; Hess, Martin; Plath, Martin

    2011-01-01

    Fishes show an amazing diversity in hearing abilities, inner ear structures, and otolith morphology. Inner ear morphology, however, has not yet been investigated in detail in any member of the diverse order Cyprinodontiformes. We, therefore, studied the inner ear of the cyprinodontiform freshwater fish Poecilia mexicana by analyzing the position of otoliths in situ, investigating the 3D structure of sensory epithelia, and examining the orientation patterns of ciliary bundles of the sensory hair cells, while combining μ-CT analyses, scanning electron microscopy, and immunocytochemical methods. P. mexicana occurs in different ecotypes, enabling us to study the intra-specific variability (on a qualitative basis) of fish from regular surface streams, and the Cueva del Azufre, a sulfidic cave in southern Mexico. The inner ear of Poecilia mexicana displays a combination of several remarkable features. The utricle is connected rostrally instead of dorso-rostrally to the saccule, and the macula sacculi, therefore, is very close to the utricle. Moreover, the macula sacculi possesses dorsal and ventral bulges. The two studied ecotypes of P. mexicana showed variation mainly in the shape and curvature of the macula lagenae, in the curvature of the macula sacculi, and in the thickness of the otolithic membrane. Our study for the first time provides detailed insights into the auditory periphery of a cyprinodontiform inner ear and thus serves a basis--especially with regard to the application of 3D techniques--for further research on structure-function relationships of inner ears within the species-rich order Cyprinodontiformes. We suggest that other poeciliid taxa, or even other non-poeciliid cyprinodontiforms, may display similar inner ear morphologies as described here.

  5. Diagnosis and treatment of gastroesophageal reflux disease: recommendations of the Asociación Mexicana de Gastroenterología.

    PubMed

    Huerta-Iga, F; Bielsa-Fernández, M V; Remes-Troche, J M; Valdovinos-Díaz, M A; Tamayo-de la Cuesta, J L

    Emerging concepts in the pathophysiology of gastroesophageal reflux disease (GERD) and the constant technologic advances in the diagnosis and treatment of this clinical condition make it necessary to frequently review and update the clinical guidelines, recommendations, and official statements from the leading academic groups worldwide. The Asociación Mexicana de Gastroenterología (AMG), aware of this responsibility, brought together national experts in this field to analyze the most recent scientific evidence and formulate a series of practical recommendations to guide and facilitate the diagnostic process and efficacious treatment of these patients. The document includes algorithms, figures, and tables for convenient consultation, along with opinions on GERD management in sensitive populations, such as pregnant women and older adults. Copyright © 2016 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.

  6. Color and shape discrimination in the stingless bee Scaptotrigona mexicana Guérin (Hymenoptera, Apidae).

    PubMed

    Sánchez, D; Vandame, R

    2012-06-01

    To increase our understanding in bee vision ecology, we investigated the color and shape discrimination performance of the stingless bee Scaptotrigona mexicana Guérin. Our main goal was to describe the choice behavior of experienced foragers over time, trying to understand to what extent color and shape stimuli (separately tested) aid them to choose the rewarding option, in the presence of distracting, unrewarding stimuli. Single foragers were trained to collect sucrose solution from a target plate. Afterwards, one distracting, unrewarding plate was placed besides the target plate and eight choices were recorded. Our results showed that both color and shape stimuli assisted efficiently the trained foragers in locating the target plate. However, foragers chose significantly more often the target plate in the color experiments than in the shape experiments. In conclusion, in our experimental setup, color was of better assistance to the foragers of S. mexicana than shape to choose their rewards. This is the first study in which it is demonstrated that the choice performance over time in a stingless bee depends upon the characteristics of the resource, such as shape and color.

  7. Specific immunization of mice against Leishmania mexicana amazonensis using solubilized promastigotes

    NASA Technical Reports Server (NTRS)

    Barral-Netto, M.; Sadigursky, M.; Reed, S. G.; Sonnenfeld, G.

    1987-01-01

    In this work, it was demonstrated that mice (BALB/c strain) highly susceptible to Leishmania mexicana amazonensis can be protected against infection by this parasite by being preimmunized with whole solubilized (in a buffer that contained EDTA, NP-40, and SDS) promastigotes; the use of adjuvant or intact inactivated parasite cells is shown to be not necessary. The best immunization schedule consisted of three intravenous injections of 5 x 10 to the 7th parasite equivalents, administered one to eight weeks before infection. Immunized mice exhibited a marked inhibition of primary lesion development, reduced numbers of parasites in the spleen, and reduced death rate.

  8. Genetic diversity, mating system, and conservation of a Mexican subalpine relict, Picea mexicana Martínez

    Treesearch

    F. Thomas Ledig; Paul D. Hodgskiss; Virginia Jacob-Cervantes

    2002-01-01

    Mexican spruce (Picea mexicana Martínez), an endangered species of the highest sky islands in México’s Sierra Madre Oriental and Sierra Madre Occidental, is threatened by fire, grazing, and global warming. Its conservation depends on whether it also is threatened by inbreeding and loss of genic diversity. We used 18 isozyme markers in 12 enzyme...

  9. Toxic hydrogen sulphide and dark caves: pronounced male life-history divergence among locally adapted Poecilia mexicana (Poeciliidae).

    PubMed

    Riesch, R; Plath, M; Schlupp, I

    2011-03-01

    Chronic environmental stress is known to induce evolutionary change. Here, we assessed male life-history trait divergence in the neotropical fish Poecilia mexicana from a system that has been described to undergo incipient ecological speciation in adjacent, but reproductively isolated toxic/nontoxic and surface/cave habitats. Examining both field-caught and common garden-reared specimens, we investigated the extent of differentiation and plasticity of life-history strategies employed by male P. mexicana. We found strong site-specific life-history divergence in traits such as fat content, standard length and gonadosomatic index. The majority of site-specific life-history differences were also expressed under common garden-rearing conditions. We propose that apparent conservatism of male life histories is the result of other (genetically based) changes in physiology and behaviour between populations. Together with the results from previous studies, this is strong evidence for local adaptation as a result of ecologically based divergent selection. © 2010 The Authors. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology.

  10. Tourism values for Mexican free-tailed bat (Tadarida brasiliensis mexicana) viewing

    USGS Publications Warehouse

    Bagstad, Kenneth J.; Widerholdt, Ruscena

    2013-01-01

    Migratory species provide diverse ecosystem services to people, but these values have seldom been estimated rangewide for a single species. In this article, we summarize visitation and consumer surplus for recreational visitors to viewing sites for the Mexican free-tailed bat (Tadarida brasiliensis mexicana) throughout the Southwestern United States. Public bat viewing opportunities are available at 17 of 25 major roosts across six states; on an annual basis, we estimate that over 242,000 visitors view bats, gaining over $6.5 million in consumer surplus. A better understanding of spatial mismatches between the areas where bats provide value to people and areas most critical for maintaining migratory populations can better inform conservation planning, including economic incentive systems for conservation.

  11. Outbreeding and lack of temporal genetic structure in a drone congregation of the neotropical stingless bee Scaptotrigona mexicana.

    PubMed

    Mueller, Matthias Y; Moritz, Robin Fa; Kraus, F Bernhard

    2012-06-01

    Drone aggregations are a widespread phenomenon in many stingless bee species (Meliponini), but the ultimate and proximate causes for their formation are still not well understood. One adaptive explanation for this phenomenon is the avoidance of inbreeding, which is especially detrimental for stingless bees due to the combined effects of the complementary sex-determining system and the small effective population size caused by eusociality and monandry. We analyzed the temporal genetic dynamics of a drone aggregation of the stingless bee Scaptotrigona mexicana with microsatellite markers over a time window of four weeks. We estimated the drones of the aggregation to originate from a total of 55 colonies using sibship re-construction. There was no detectable temporal genetic differentiation or sub-structuring in the aggregation. Most important, we could exclude all colonies in close proximity of the aggregation as origin of the drones in the aggregation, implicating that they originate from more distant colonies. We conclude that the diverse genetic composition and the distant origin of the drones of the S. mexicana drone congregation provides an effective mechanism to avoid mating among close relatives.

  12. Yellow colored blooms of Argemone mexicana and Turnera ulmifolia mediated synthesis of silver nanoparticles and study of their antibacterial and antioxidant activity

    NASA Astrophysics Data System (ADS)

    Chandrasekhar, N.; Vinay, S. P.

    2017-11-01

    In the present work, AgNPs were prepared using a simple bio-reduction method. This is ecologically welcoming and cost-effective method. Yellow colored blooms concentrate of Argemone mexicana and Turnera ulmifolia are used as bio reducing agents in the study. The formation of silver nanoparticles was confirmed by UV-Vis spectrophotometer and characterization of the nanoparticles was done by FTIR, SEM, XRD and EDX. The Antibacterial action of silver nanoparticles was tested against Staphylococus aureus, Pseudomonas aeruginosa, Escherichia coli and Klebsiella aerogenes. The phytochemical analysis of the blooms concentrate has shown the existence of saponins, alkaloids, amino acids, phenols, tannins, terpenoids, flavonoids and cardiac glycosides. In vitro anti-oxidant action of both A. mexicana and T. ulmifolia AgNPs were studied by DPPH assay and reducing power assay.

  13. Vegetation patches improve the establishment of Salvia mexicana seedlings by modifying microclimatic conditions

    NASA Astrophysics Data System (ADS)

    Mendoza-Hernández, Pedro E.; Rosete-Rodríguez, Alejandra; Sánchez-Coronado, María E.; Orozco, Susana; Pedrero-López, Luis; Méndez, Ignacio; Orozco-Segovia, Alma

    2014-07-01

    Human disturbance has disrupted the dynamics of plant communities. To restore these dynamics, we could take advantage of the microclimatic conditions generated by remaining patches of vegetation and plastic mulch. These microclimatic conditions might have great importance in restoring disturbed lava fields located south of Mexico City, where the rock is exposed and the soil is shallow. We evaluated the effects of both the shade projected by vegetation patches and plastic mulch on the mean monthly soil surface temperature ( T ss) and photosynthetic photon flux density (PPFD) and on the survival and growth of Salvia mexicana throughout the year. This species was used as a phytometer of microsite quality. Shade reduced the T ss to a greater extent than mulch did. Both survival and growth were enhanced by shade and mulch, and the PPFD was related with seedling growth. During the dry season, plant biomass was lost, and there was a negative effect of PPFD on plant growth. At micro-meteorological scales, the use of shade projected by patches of vegetation and mulch significantly reduced the mortality of S. mexicana and enhanced its growth. Survival and growth of this plant depended on the environmental quality of microsites on a small scale, which was determined by the environmental heterogeneity of the patches and the landscape. For plant restoration, microsite quality must be evaluated on small scales, but on a large scale it may be enough to take advantage of landscape shade dynamics and the use of mulch to increase plant survival and growth.

  14. Vegetation patches improve the establishment of Salvia mexicana seedlings by modifying microclimatic conditions.

    PubMed

    Mendoza-Hernández, Pedro E; Rosete-Rodríguez, Alejandra; Sánchez-Coronado, María E; Orozco, Susana; Pedrero-López, Luis; Méndez, Ignacio; Orozco-Segovia, Alma

    2014-07-01

    Human disturbance has disrupted the dynamics of plant communities. To restore these dynamics, we could take advantage of the microclimatic conditions generated by remaining patches of vegetation and plastic mulch. These microclimatic conditions might have great importance in restoring disturbed lava fields located south of Mexico City, where the rock is exposed and the soil is shallow. We evaluated the effects of both the shade projected by vegetation patches and plastic mulch on the mean monthly soil surface temperature (Tss) and photosynthetic photon flux density (PPFD) and on the survival and growth of Salvia mexicana throughout the year. This species was used as a phytometer of microsite quality. Shade reduced the T ss to a greater extent than mulch did. Both survival and growth were enhanced by shade and mulch, and the PPFD was related with seedling growth. During the dry season, plant biomass was lost, and there was a negative effect of PPFD on plant growth. At micro-meteorological scales, the use of shade projected by patches of vegetation and mulch significantly reduced the mortality of S. mexicana and enhanced its growth. Survival and growth of this plant depended on the environmental quality of microsites on a small scale, which was determined by the environmental heterogeneity of the patches and the landscape. For plant restoration, microsite quality must be evaluated on small scales, but on a large scale it may be enough to take advantage of landscape shade dynamics and the use of mulch to increase plant survival and growth.

  15. Experience, but not distance, influences the recruitment precision in the stingless bee Scaptotrigona mexicana

    NASA Astrophysics Data System (ADS)

    Sánchez, Daniel; Kraus, F. Bernhard; Hernández, Manuel De Jesús; Vandame, Rémy

    2007-07-01

    Recruitment precision, i.e. the proportion of recruits that reach an advertised food source, is a crucial adaptation of social bees to their environment. Studies with honeybees showed that recruitment precision is not a fixed feature, but it may be enhanced by factors like experience and distance. However, little is known regarding the recruitment precision of stingless bees. Hence, in this study, we examined the effects of experience and spatial distance on the precision of the food communication system of the stingless bee Scaptotrigona mexicana. We conducted the experiments by training bees to a three-dimensional artificial patch at several distances from the colony. We recorded the choices of individual recruited foragers, either being newcomers (foragers without experience with the advertised food source) or experienced (foragers that had previously visited the feeder). We found that the average precision of newcomers (95.6 ± 2.61%) was significantly higher than that of experienced bees (80.2 ± 1.12%). While this might seem counter-intuitive on first sight, this “loss” of precision can be explained by the tendency of experienced recruits to explore nearby areas to find new rewarding food sources after they had initially learned the exact location of the food source. Increasing the distance from the colony had no significant effect on the precision of the foraging bees. Thus, our data show that experience, but not the distance of the food source, affected the patch precision of S. mexicana foragers.

  16. The Mexican Seismic Network (Red Sísmica Mexicana)

    NASA Astrophysics Data System (ADS)

    Valdes-Gonzales, C. M.; Arreola-Manzano, J.; Castelan-Pescina, G.; Alonso-Rivera, P.; Saldivar-Rangel, M. A.; Rodriguez-Arteaga, O. O.; Lopez-Lena-Villasana, R.

    2014-12-01

    The Mexican Seismic Network (Red Sísmica Mexicana) was created to give sufficient information and opportune to make decisions in order to mitigate seismic and tsunami risk. This was a Mexican government initiative headed by CENAPRED (National Disaster Prevention Center) who made an effort to integrated academic institutions and civil agencies to work together through a collaboration agreement. This network is supported by Universidad National Autónoma de México (UNAM) and its seismic networks (Broad Band and Strong Motion), the Centro de Instrumentación y Registro Sismico (CIRES) with its Earthquake Early Warning System that covers the Guerrero Gap and Oaxaca earthquakes, The Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE) with the support of its expertise in tsunami observation and the Secretaria de Marina (SEMAR) to monitor the sea level and operate the Mexican Tsunami Warning Center. The institutions involved in this scope have the compromise to interchange and share the data and advice to the Civil Protection authorities.

  17. Growth and enzymatic activity of Leucoagaricus gongylophorus, a mutualistic fungus isolated from the leaf-cutting ant Atta mexicana, on cellulose and lignocellulosic biomass.

    PubMed

    Vigueras, G; Paredes-Hernández, D; Revah, S; Valenzuela, J; Olivares-Hernández, R; Le Borgne, S

    2017-08-01

    A mutualistic fungus of the leaf-cutting ant Atta mexicana was isolated and identified as Leucoagaricus gongylophorus. This isolate had a close phylogenetic relationship with L. gongylophorus fungi cultivated by other leaf-cutting ants as determined by ITS sequencing. A subcolony started with ~500 A. mexicana workers could process 2 g day -1 of plant material and generate a 135 cm 3 fungus garden in 160 days. The presence of gongylidia structures of ~35 μm was observed on the tip of the hyphae. The fungus could grow without ants on semi-solid cultures with α-cellulose and microcrystalline cellulose and in solid-state cultures with grass and sugarcane bagasse, as sole sources of carbon. The maximum CO 2 production rate on grass (V max  = 17·5 mg CO 2  L g -1  day -1 ) was three times higher than on sugarcane bagasse (V max  = 6·6 mg CO 2  L g -1 day -1 ). Recoveries of 32·9 mg glucose  g biomass -1 and 12·3 mg glucose  g biomass -1 were obtained from the fungal biomass and the fungus garden, respectively. Endoglucanase activity was detected on carboxymethylcellulose agar plates. This is the first study reporting the growth of L. gongylophorus from A. mexicana on cellulose and plant material. According to the best of our knowledge, this is the first report about the growth of Leucoagaricus gongylophorus, isolated from the colony of the ant Atta mexicana, on semisolid medium with cellulose and solid-state cultures with lignocellulosic materials. The maximum CO 2 production rate on grass was three times higher than on sugarcane bagasse. Endoglucanase activity was detected and it was possible to recover glucose from the fungal gongylidia. The cellulolytic activity could be used to process lignocellulosic residues and obtain sugar or valuable products, but more work is needed in this direction. © 2017 The Society for Applied Microbiology.

  18. Outbreeding and lack of temporal genetic structure in a drone congregation of the neotropical stingless bee Scaptotrigona mexicana

    PubMed Central

    Mueller, Matthias Y; Moritz, Robin FA; Kraus, F Bernhard

    2012-01-01

    Drone aggregations are a widespread phenomenon in many stingless bee species (Meliponini), but the ultimate and proximate causes for their formation are still not well understood. One adaptive explanation for this phenomenon is the avoidance of inbreeding, which is especially detrimental for stingless bees due to the combined effects of the complementary sex-determining system and the small effective population size caused by eusociality and monandry. We analyzed the temporal genetic dynamics of a drone aggregation of the stingless bee Scaptotrigona mexicana with microsatellite markers over a time window of four weeks. We estimated the drones of the aggregation to originate from a total of 55 colonies using sibship re-construction. There was no detectable temporal genetic differentiation or sub-structuring in the aggregation. Most important, we could exclude all colonies in close proximity of the aggregation as origin of the drones in the aggregation, implicating that they originate from more distant colonies. We conclude that the diverse genetic composition and the distant origin of the drones of the S. mexicana drone congregation provides an effective mechanism to avoid mating among close relatives. PMID:22833802

  19. Two Lactarius species associated with a relict Fagus grandifolia var. mexicana population in a Mexican montane cloud forest.

    PubMed

    Montoya, L; Haug, I; Bandala, V M

    2010-01-01

    Ectomycorrhizal (EM) fleshy fungi are being monitored in a population of Fagus grandifolia var. mexicana persisting in a montane cloud forest refuge on a volcano in a subtropical region of central Veracruz (eastern Mexico). The population of Fagus studied represents one of the 10 recognized forest fragments still housing this tree genus in Mexico. This is the first attempt to document EM fungi associated with this tree species in Mexico. We present evidence of the ectomycorrhizal symbiosis for Lactarius badiopallescens and L. cinereus with this endemic tree. Species identification of Lactarius on Fagus grandifolia var. mexicana was based on the comparison of DNAsequences (ITS rDNA) of spatiotemporally co-occurring basidiomes and EM root tips. The host of the EM tips was identified by comparison of the large subunit of the ribulose-bisphosphate carboxylase gene (rbcL). The occurrence of Lactarius badiopallescens and L. cinereus populations in the area of study represent the southernmost record known to date of these two species in North America and are new for the Neotropical Lactarius mycota. Descriptions coupled with illustrations of macro- and micromorphological features of basidiomes as well as photographs of ectomycorrhizas are presented.

  20. A new species and a new record of Laccaria (Fungi, Basidiomycota) found in a relict forest of the endangered Fagus grandifolia var. mexicana

    PubMed Central

    Ramos, Antero; Bandala, Victor M.; Montoya, Leticia

    2017-01-01

    Abstract Two species of Laccaria discovered in relicts of Fagus grandifolia var. mexicana forests in eastern Mexico are described based on the macro- and micromorphological features, and their identity supported by molecular analysis of the internal transcribed spacer (ITS) and large subunit (LSU) of the ribosomal RNA gene. The phylogeny obtained here showed that one of the Mexican species is nested in an exclusive clade which in combination with its striking morphological features, infers that it represents a new species, while the other species is placed as a member in the Laccaria trichodermophora clade. This is the first report in Mexico of Laccaria with Fagus grandifolia var. mexicana trees, with which the reported species may form ectomycorrhizal association. Descriptions are accompanied with illustrations of macro- and micromorphological characters and a discussion of related taxa are presented. PMID:29559819

  1. Toxic hydrogen sulfide and dark caves: life-history adaptations in a livebearing fish (Poecilia mexicana, Poeciliidae).

    PubMed

    Riesch, Rüdiger; Plath, Martin; Schlupp, Ingo

    2010-05-01

    Life-history traits are very sensitive to extreme environmental conditions, because resources that need to be invested in somatic maintenance cannot be invested in reproduction. Here we examined female life-history traits in the Mexican livebearing fish Poecilia mexicana from a variety of benign surface habitats, a creek with naturally occurring toxic hydrogen sulfide (H2S), a sulfidic cave, and a non-sulfidic cave. Previous studies revealed pronounced genetic and morphological divergence over very small geographic scales in this system despite the absence of physical barriers, suggesting that local adaptation to different combinations of two selection factors, toxicity (H2S) and darkness, is accompanied by very low rates of gene flow. Hence, we investigated life-history divergence between these populations in response to the selective pressures of darkness and/or toxicity. Our main results show that toxicity and darkness both select for (or impose constraints on) the same female trait dynamics: reduced fecundity and increased offspring size. Since reduced fecundity in the sulfur cave population was previously shown to be heritable, we discuss how divergent life-history evolution may promote further ecological divergence: for example, reduced fecundity and increased offspring autonomy are clearly beneficial in extreme environments, but fish with these traits are outcompeted in benign habitats.

  2. Comparative assessment of a DNA and protein Leishmania donovani gamma glutamyl cysteine synthetase vaccine to cross-protect against murine cutaneous leishmaniasis caused by L. major or L. mexicana infection.

    PubMed

    Campbell, S A; Alawa, J; Doro, B; Henriquez, F L; Roberts, C W; Nok, A; Alawa, C B I; Alsaadi, M; Mullen, A B; Carter, K C

    2012-02-08

    Leishmaniasis is a major health problem and it is estimated that 12 million people are currently infected. A vaccine which could cross-protect people against different Leishmania spp. would facilitate control of this disease as more than one species of Leishmania may be present. In this study the ability of a DNA vaccine, using the full gene sequence for L. donovani gamma glutamyl cysteine synthetase (γGCS) incorporated in the pVAX vector (pVAXγGCS), and a protein vaccine, using the corresponding recombinant L. donovani γGCS protein (LdγGCS), to protect against L. major or L. mexicana infection was evaluated. DNA vaccination gave transient protection against L. major and no protection against L. mexicana despite significantly enhancing specific antibody titres in vaccinated infected mice compared to infected controls. Vaccination with the LdγGCS protected against both species but only if the protein was incorporated into non-ionic surfactant vesicles for L. mexicana. The results of this study indicate that a L. donovani γGCS vaccine could be used to vaccinate against more than one Leishmania species but only if the recombinant protein is used. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Effect of GF-120 (Spinosad) Aerial Sprays on Colonies of the Stingless Bee Scaptotrigona mexicana (Hymenoptera: Apidae) and the Honey Bee (Hymenoptera: Apidae).

    PubMed

    Gómez-Escobar, Enoc; Liedo, Pablo; Montoya, Pablo; Méndez-Villarreal, Agustín; Guzmán, Miguel; Vandame, Rémy; Sánchez, Daniel

    2018-06-02

    Despite their relevant contribution to the conservation of tropical ecosystems and crop productivity through pollination, the stingless bees (Apidae: Meliponini) can be considered a group of neglected species in the assessment of pesticides upon nontarget organisms. In this article, we evaluated the effect of aerial sprays of the spinosad-based fruit fly toxic bait GF-120 upon colonies of the stingless bee Scaptotrigona mexicana Guérin (Hymenoptera: Apidae), an economically important and abundant species in some landscapes of Mexico, located in mango orchards. Colonies of the honey bee Apis mellifera L. (Hymenoptera: Apidae) were used for comparison. Eight colonies (four of A. mellifera and four of S. mexicana) were moved into each of two mango orchards, one was used as a control, with no insecticide application, and other received five weekly aerial sprays of GF-120. Foraging activity and strength of colonies of both species were measured nine times over the fruiting season, previous, during and after insecticide application. We did not find a significant difference in foraging activity and strength between exposed and control colonies of A. mellifera during the observation period. However, colonies of S. mexicana seemed to be affected by the exposure, as revealed by a reduction in colony strength. However, 1 yr later, with no insecticide applications, the colonies of both species were evaluated and found to be in good conditions. Our results showed that weekly aerial sprays of GF-120 are unlikely to generate acute poisoning in both species, even if in acute toxicity tests this product has been found to be highly active.

  4. Gene disruptions indicate an essential function for the LmmCRK1 cdc2-related kinase of Leishmania mexicana.

    PubMed

    Mottram, J C; McCready, B P; Brown, K G; Grant, K M

    1996-11-01

    The generation of homozygous null mutants for the crk1 Cdc2-Related Kinase of Leishmania mexicana was attempted using targeted gene disruption. Promastigote mutants heterozygous for crk1 were readily isolated with a hyg-targeting fragment, but attempts to create null mutants by second-round transfections with a bie-targeting fragment yielded two classes of mutant, neither of which was null. First, the transfected fragment formed an episome; second, the cloned transfectants were found to contain wild-type crk1 alleles as well as hyg and ble integrations. DNA-content analysis revealed that these mutants were triploid or tetraploid. Plasticity in chromosome number following targeting has been proposed as a means by which Leishmania avoids deletion of essential genes. These data support this theory and implicate crk1 as an essential gene, validating CRK1 as a potential drug target. L mexicana transfected with a Trypanosoma brucel homologue, tbcrk1, was shown to be viable in an immcrk1 null background, thus showing complementation of function between these trypanosomatid genes. The expression of crk1 was further manipulated by engineering a six-histidine tag at the C-terminus of the kinase, allowing purification of the active complex by affinity selection on Nl(2+)-nitriloacetic acid (NTA) agarose.

  5. Toxic hydrogen sulfide and dark caves: phenotypic and genetic divergence across two abiotic environmental gradients in Poecilia mexicana.

    PubMed

    Tobler, Michael; Dewitt, Thomas J; Schlupp, Ingo; García de León, Francisco J; Herrmann, Roger; Feulner, Philine G D; Tiedemann, Ralph; Plath, Martin

    2008-10-01

    Divergent natural selection drives evolutionary diversification. It creates phenotypic diversity by favoring developmental plasticity within populations or genetic differentiation and local adaptation among populations. We investigated phenotypic and genetic divergence in the livebearing fish Poecilia mexicana along two abiotic environmental gradients. These fish typically inhabit nonsulfidic surface rivers, but also colonized sulfidic and cave habitats. We assessed phenotypic variation among a factorial combination of habitat types using geometric and traditional morphometrics, and genetic divergence using quantitative and molecular genetic analyses. Fish in caves (sulfidic or not) exhibited reduced eyes and slender bodies. Fish from sulfidic habitats (surface or cave) exhibited larger heads and longer gill filaments. Common-garden rearing suggested that these morphological differences are partly heritable. Population genetic analyses using microsatellites as well as cytochrome b gene sequences indicate high population differentiation over small spatial scale and very low rates of gene flow, especially among different habitat types. This suggests that divergent environmental conditions constitute barriers to gene flow. Strong molecular divergence over short distances as well as phenotypic and quantitative genetic divergence across habitats in directions classic to fish ecomorphology suggest that divergent selection is structuring phenotypic variation in this system.

  6. Regulated Degradation of an Endoplasmic Reticulum Membrane Protein in a Tubular Lysosome in Leishmania mexicana

    PubMed Central

    Mullin, Kylie A.; Foth, Bernardo J.; Ilgoutz, Steven C.; Callaghan, Judy M.; Zawadzki, Jody L.; McFadden, Geoffrey I.; McConville, Malcolm J.

    2001-01-01

    The cell surface of the human parasite Leishmania mexicana is coated with glycosylphosphatidylinositol (GPI)-anchored macromolecules and free GPI glycolipids. We have investigated the intracellular trafficking of green fluorescent protein- and hemagglutinin-tagged forms of dolichol-phosphate-mannose synthase (DPMS), a key enzyme in GPI biosynthesis in L. mexicana promastigotes. These functionally active chimeras are found in the same subcompartment of the endoplasmic reticulum (ER) as endogenous DPMS but are degraded as logarithmically growing promastigotes reach stationary phase, coincident with the down-regulation of endogenous DPMS activity and GPI biosynthesis in these cells. We provide evidence that these chimeras are constitutively transported to and degraded in a novel multivesicular tubule (MVT) lysosome. This organelle is a terminal lysosome, which is labeled with the endocytic marker FM 4-64, contains lysosomal cysteine and serine proteases and is disrupted by lysomorphotropic agents. Electron microscopy and subcellular fractionation studies suggest that the DPMS chimeras are transported from the ER to the lumen of the MVT via the Golgi apparatus and a population of 200-nm multivesicular bodies. In contrast, soluble ER proteins are not detectably transported to the MVT lysosome in either log or stationary phase promastigotes. Finally, the increased degradation of the DPMS chimeras in stationary phase promastigotes coincides with an increase in the lytic capacity of the MVT lysosome and changes in the morphology of this organelle. We conclude that lysosomal degradation of DPMS may be important in regulating the cellular levels of this enzyme and the stage-dependent biosynthesis of the major surface glycolipids of these parasites. PMID:11514622

  7. High precision during food recruitment of experienced (reactivated) foragers in the stingless bee Scaptotrigona mexicana (Apidae, Meliponini)

    NASA Astrophysics Data System (ADS)

    Sánchez, Daniel; Nieh, James C.; Hénaut, Yann; Cruz, Leopoldo; Vandame, Rémy

    Several studies have examined the existence of recruitment communication mechanisms in stingless bees. However, the spatial accuracy of location-specific recruitment has not been examined. Moreover, the location-specific recruitment of reactivated foragers, i.e., foragers that have previously experienced the same food source at a different location and time, has not been explicitly examined. However, such foragers may also play a significant role in colony foraging, particularly in small colonies. Here we report that reactivated Scaptotrigona mexicana foragers can recruit with high precision to a specific food location. The recruitment precision of reactivated foragers was evaluated by placing control feeders to the left and the right of the training feeder (direction-precision tests) and between the nest and the training feeder and beyond it (distance-precision tests). Reactivated foragers arrived at the correct location with high precision: 98.44% arrived at the training feeder in the direction trials (five-feeder fan-shaped array, accuracy of at least +/-6° of azimuth at 50 m from the nest), and 88.62% arrived at the training feeder in the distance trials (five-feeder linear array, accuracy of at least +/-5 m or +/-10% at 50 m from the nest). Thus, S. mexicana reactivated foragers can find the indicated food source at a specific distance and direction with high precision, higher than that shown by honeybees, Apis mellifera, which do not communicate food location at such close distances to the nest.

  8. Gradient Evolution of Body Colouration in Surface- and Cave-Dwelling Poecilia mexicana and the Role of Phenotype-Assortative Female Mate Choice

    PubMed Central

    Penshorn, Marina; Hamfler, Sybille; Herbert, Denise B.; Appel, Jessica; Meyer, Philipp; Slattery, Patrick; Charaf, Sarah; Wolf, Raoul; Völker, Johannes; Berger, Elisabeth A. M.; Dröge, Janis; Riesch, Rüdiger; Arias-Rodriguez, Lenin; Indy, Jeanne R.; Plath, Martin

    2013-01-01

    Ecological speciation assumes reproductive isolation to be the product of ecologically based divergent selection. Beside natural selection, sexual selection via phenotype-assortative mating is thought to promote reproductive isolation. Using the neotropical fish Poecilia mexicana from a system that has been described to undergo incipient ecological speciation in adjacent, but ecologically divergent habitats characterized by the presence or absence of toxic H2S and darkness in cave habitats, we demonstrate a gradual change in male body colouration along the gradient of light/darkness, including a reduction of ornaments that are under both inter- and intrasexual selection in surface populations. In dichotomous choice tests using video-animated stimuli, we found surface females to prefer males from their own population over the cave phenotype. However, female cave fish, observed on site via infrared techniques, preferred to associate with surface males rather than size-matched cave males, likely reflecting the female preference for better-nourished (in this case: surface) males. Hence, divergent selection on body colouration indeed translates into phenotype-assortative mating in the surface ecotype, by selecting against potential migrant males. Female cave fish, by contrast, do not have a preference for the resident male phenotype, identifying natural selection against migrants imposed by the cave environment as the major driver of the observed reproductive isolation. PMID:24175282

  9. The role of Revista Mexicana de Astronomía y Astrofísica Serie de Conferencias in the world of astronomy

    NASA Astrophysics Data System (ADS)

    Torres-Peimbert, Silvia; Allen, Christine

    2015-08-01

    Forty years ago Revista Mexicana de Astronomía y Astrofísica decided to include the proceedings of astronomical meetings in Mexico and Latin America. In 1995 it became necessary to found the Serie de Conferencias to better differentiate proceedings from refereed papers.So far there have been 58 astronomical meetings published and there are several more in store for the coming years

  10. Female Choice Undermines the Emergence of Strong Sexual Isolation between Locally Adapted Populations of Atlantic Mollies (Poecilia mexicana)

    PubMed Central

    Zimmer, Claudia; Bierbach, David; Arias-Rodriguez, Lenin; Plath, Martin

    2018-01-01

    Divergent selection between ecologically dissimilar habitats promotes local adaptation, which can lead to reproductive isolation (RI). Populations in the Poecilia mexicana species complex have independently adapted to toxic hydrogen sulfide and show varying degrees of RI. Here, we examined the variation in the mate choice component of prezygotic RI. Mate choice tests across drainages (with stimulus males from another drainage) suggest that specific features of the males coupled with a general female preference for yellow color patterns explain the observed variation. Analyses of male body coloration identified the intensity of yellow fin coloration as a strong candidate to explain this pattern, and common-garden rearing suggested heritable population differences. Male sexual ornamentation apparently evolved differently across sulfide-adapted populations, for example because of differences in natural counterselection via predation. The ubiquitous preference for yellow color ornaments in poeciliid females likely undermines the emergence of strong RI, as female discrimination in favor of own males becomes weaker when yellow fin coloration in the respective sulfide ecotype increases. Our study illustrates the complexity of the (partly non-parallel) pathways to divergence among replicated ecological gradients. We suggest that future work should identify the genomic loci involved in the pattern reported here, making use of the increasing genomic and transcriptomic datasets available for our study system. PMID:29724050

  11. Leishmania mexicana: promastigotes and amastigotes secrete protein phosphatases and this correlates with the production of inflammatory cytokines in macrophages.

    PubMed

    Escalona-Montaño, A R; Ortiz-Lozano, D M; Rojas-Bernabé, A; Wilkins-Rodriguez, A A; Torres-Guerrero, H; Mondragón-Flores, R; Mondragón-Gonzalez, R; Becker, I; Gutiérrez-Kobeh, L; Aguirre-Garcia, M M

    2016-09-01

    Phosphatase activity of Leishmania spp. has been shown to deregulate the signalling pathways of the host cell. We here show that Leishmania mexicana promastigotes and amastigotes secrete proteins with phosphatase activity to the culture medium, which was higher in the Promastigote Secretion Medium (PSM) as compared with the Amastigote Secretion Medium (ASM) and was not due to cell lysis, since parasite viability was not affected by the secretion process. The biochemical characterization showed that the phosphatase activity present in PSM was higher in dephosphorylating the peptide END (pY) INASL as compared with the peptide RRA (pT)VA. In contrast, the phosphatase activity in ASM showed little dephosphorylating capacity for both peptides. Inhibition assays demonstrated that the phosphatase activity of both PSM and ASM was sensible only to protein tyrosine phosphatases inhibitors. An antibody against a protein phosphatase 2C (PP2C) of Leishmania major cross-reacted with a 44·9 kDa molecule in different cellular fractions of L. mexicana promastigotes and amastigotes, however, in PSM and ASM, the antibody recognized a protein about 70 kDa. By electron microscopy, the PP2C was localized in the flagellar pocket of amastigotes. PSM and ASM induced the production of tumor necrosis factor alpha, IL-1β, IL-12p70 and IL-10 in human macrophages.

  12. Central nervous system effects and chemical composition of two subspecies of Agastache mexicana; an ethnomedicine of Mexico.

    PubMed

    Estrada-Reyes, Rosa; López-Rubalcava, C; Ferreyra-Cruz, Octavio Alberto; Dorantes-Barrón, Ana María; Heinze, G; Moreno Aguilar, Julia; Martínez-Vázquez, Mariano

    2014-04-11

    Agastache mexicana subspecies mexicana (Amm) and xolocotziana (Amx) are used in Mexican traditional medicine to relief cultural affiliation syndromes known as "susto" or "espanto", for "nervous" condition, and as a sleep aid. Despite its intensive use, neuropharmacological studies are scarce, and the chemical composition of the aqueous extracts has not been described. Aims of the study are: (1) To analyze the chemical composition of aqueous extracts from aerial parts of Amm and Amx. (2) To evaluate the anxiolytic-like, sedative, antidepressant-like effects. (3) Analyze the general toxic effects of different doses. Anxiolytic-like and sedative effects were measured in the avoidance exploratory behavior, burying behavior and the hole-board tests. The antidepressant-like actions were studied in the forced swimming and tail suspension tests. Finally, general activity and motor coordination disturbances were evaluated in the open field, inverted screen and rota-rod tests. The acute toxicity of Amm and Amx was determined by calculating their LD50 (mean lethal dose). The chemical analyses were performed employing chromatographic, photometric and HPLC-ESI-MS techniques. Low doses of Amm and Amx (0.1σ1.0mg/kg) induced anxiolytic-like actions; while higher doses (over 10mg/kg) induced sedation and reduced the locomotor activity, exerting a general inhibition in the central nervous system (CNS). Results support the use of Amm and Amx in traditional medicine as tranquilizers and sleep inducers. Additionally, this paper contributes to the knowledge of the chemical composition of the aqueous extracts of these plants. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. PPAR Activation Induces M1 Macrophage Polarization via cPLA2-COX-2 Inhibition, Activating ROS Production against Leishmania mexicana

    PubMed Central

    Díaz-Gandarilla, J. A.; Osorio-Trujillo, C.; Hernández-Ramírez, V. I.; Talamás-Rohana, P.

    2013-01-01

    Defence against Leishmania depends upon Th1 inflammatory response and, a major problem in susceptible models, is the turnoff of the leishmanicidal activity of macrophages with IL-10, IL-4, and COX-2 upregulation, as well as immunosuppressive PGE2, all together inhibiting the respiratory burst. Peroxisome proliferator-activated receptors (PPAR) activation is responsible for macrophages polarization on Leishmania susceptible models where microbicide functions are deactivated. In this paper, we demonstrated that, at least for L. mexicana, PPAR activation, mainly PPARγ, induced macrophage activation through their polarization towards M1 profile with the increase of microbicide activity against intracellular pathogen L. mexicana. PPAR activation induced IL-10 downregulation, whereas the production of proinflammatory cytokines such as TNF-α, IL-1β, and IL-6 remained high. Moreover, PPAR agonists treatment induced the deactivation of cPLA2-COX-2-prostaglandins pathway together with an increase in TLR4 expression, all of whose criteria meet the M1 macrophage profile. Finally, parasite burden, in treated macrophages, was lower than that in infected nontreated macrophages, most probably associated with the increase of respiratory burst in these treated cells. Based on the above data, we conclude that PPAR agonists used in this work induces M1 macrophages polarization via inhibition of cPLA2 and the increase of aggressive microbicidal activity via reactive oxygen species (ROS) production. PMID:23555077

  14. Chemical compositions and antimicrobial and antioxidant activities of the essential oils from Magnolia grandiflora, Chrysactinia mexicana, and Schinus molle found in northeast Mexico.

    PubMed

    Guerra-Boone, Laura; Alvarez-Román, Rocío; Salazar-Aranda, Ricardo; Torres-Cirio, Anabel; Rivas-Galindo, Verónica Mayela; Waksman de Torres, Noemí; González González, Gloria María; Pérez-López, Luis Alejandro

    2013-01-01

    The essential oils from Magnolia grandiflora and Chrysactinia mexicana leaves, and from Schinus molle leaves and fruit, were characterized by gas chromatography/flame-ionization detection and gas chromatography/mass spectrometry. Twenty-eight compounds from M. grandiflora leaves were identified (representing 93.6% of the total area of the gas chromatogram), with the major component being bornyl acetate (20.9%). Colorless and yellow oils were obtained from the C. mexicana leaves with 18 (86.7%) and 11 (100%) compounds identified, respectively. In both fractions, the principal component was sylvestrene (36.8% and 41.1%, respectively). The essential oils ofS. molle leaves and fruit were each separated into colorless and yellow fractions, in which 14 (98.2) and 20 (99.8%) compounds were identified. The main component was alpha-phellandrene in all fractions (between 32.8% and 45.0%). The M. grandiflora oil displayed antifungal activity against five dermatophyte strains. The oils from S. molle and M. grandiflora leaves had antimicrobial activity against Staphylococcus aureus and Streptococcus pyogenes, which cause skin infections that potentially may lead to sepsis. However, the antioxidant activities of all oils were small (half maximal effective concentration values >250 microg/mL).

  15. A new species of Lactarius (subgenus Gerardii) from two relict Fagus grandifolia var. mexicana populations in Mexican montane cloud forests.

    PubMed

    Montoya, Leticia; Bandala, Victor Manuel; Haug, Ingeborg; Stubbe, Dirk

    2012-01-01

    A new milkcap species, Lactarius fuscomarginatus, was found in the subtropical region of central Veracruz (eastern Mexico) associated with two relict populations of Fagus grandifolia var. mexicana. The species is characterized macroscopically by its dark pileus and stipe and by its distant and whitish lamellae with blackish to blackish brown edges. A molecular phylogenetic analyses based on ITS and LSU nucDNA sequences confirms the delimitation of this new taxon and places L. fuscomarginatus in subgenus Gerardii. A detailed morphological comparison is given with similar species.

  16. Transfer of phagocytosed particles to the parasitophorous vacuole of Leishmania mexicana is a transient phenomenon preceding the acquisition of annexin I by the phagosome.

    PubMed

    Collins, H L; Schaible, U E; Ernst, J D; Russell, D G

    1997-01-01

    The eukaryotic intracellular pathogen Leishmania mexicana resides inside macrophages contained within a membrane bound parasitophorous vacuole which, as it matures, acquires the characteristics of a late endosomal compartment. This study reports the selectivity of fusion of this compartment with other particle containing vacuoles. Phagosomes containing zymosan or live Listeria monocytogenes rapidly fused with L. mexicana parasitophorous vacuoles, while those containing latex beads or heat killed L. monocytogenes failed to do so. Fusigenicity of phagosomes was not primarily dependent on the receptor utilized for ingestion, as opsonization with defined ligands could not overcome the exclusion of either latex beads or heat killed organisms. However modulation of intracellular pH by pharmacological agents such as chloroquine and ammonium chloride increased delivery of live Listeria and also induced transfer of previously excluded particles. The absence of fusion correlated with the acquisition of annexin I, a putative lysosomal targeting, molecule, on the phagosome membrane. We propose that the acquisition of cellular membrane constituents such as annexin I during phagosome maturation can ultimately direct the fusion pathway of the vesicles formed and have described a model system to further document changes in vesicle fusigenicity within cells.

  17. Morphological and molecular identification of the ectomycorrhizal association of Lactarius fumosibrunneus and Fagus grandifolia var. mexicana trees in eastern Mexico.

    PubMed

    Garay-Serrano, Edith; Bandala, Victor Manuel; Montoya, Leticia

    2012-11-01

    A population of Fagus grandifolia var. mexicana (covering ca. 4.7 ha) is established in a montane cloud forest refuge at Acatlan Volcano in eastern Mexico (Veracruz State), and it represents one of only ten populations of this species known to occur in the country (each stand covers ca. 2-35 ha in extension) and one of the southernmost in the continent. Sporocarps of several ectomycorrhizal macrofungi have been observed in the area, and among them, individuals of the genus Lactarius are common in the forest. However, the morphological and molecular characterization of ectomycorrhizae is still in development. Currently, two species of Lactarius have been previously documented in the area. Through the phylogenetic analysis of the internal transcribed spacer (ITS) region from basidiomes and ectomycorrhizae, we identified the Lactarius fumosibrunneus ectomycorrhiza. The host, F. grandifolia var. mexicana, was determined comparing the amplified ITS sequence from ectomycorrhizal root tips in the GenBank database with Basic Local Alignment Search Tool. The mycorrhizal system of L. fumosibrunneus is monopodial-pyramidal, characterized by its shiny, white to silver and pruinose surface, secreting a white latex when damaged, composed of three plectenchymatous mantle layers, with diverticulated terminal elements at the outer mantle. It lacks emanating hyphae, rhizomorphs, and sclerotia. A detailed morphological and anatomical description, illustrations, and photographs of the ectomycorrhiza are presented. The comparison of L. fumosibrunneus and other Lactarius belonging to subgenus Plinthogalus is presented.

  18. Ecology of phlebotomine sandflies and putative reservoir hosts of leishmaniasis in a border area in Northeastern Mexico: implications for the risk of transmission of Leishmania mexicana in Mexico and the USA

    PubMed Central

    Rodríguez-Rojas, Jorge J.; Rodríguez-Moreno, Ángel; Berzunza-Cruz, Miriam; Gutiérrez-Granados, Gabriel; Becker, Ingeborg; Sánchez-Cordero, Victor; Stephens, Christopher R.; Fernández-Salas, Ildefonso; Rebollar-Téllez, Eduardo A.

    2017-01-01

    Leishmaniases are a group of important diseases transmitted to humans through the bite of sandfly vectors. Several forms of leishmaniases are endemic in Mexico and especially in the Southeast region. In the Northeastern region, however, there have only been isolated reports of cases and scanty records of sandfly vectors. The main objective of this study was to analyze the diversity of sandflies and potential reservoir hosts of Leishmania spp. in the states of Nuevo León and Tamaulipas. Species richness and abundances of sandflies and rodents were recorded. A fraction of the caught sandflies was analyzed by PCR to detect Leishmania spp. Tissues from captured rodents were also screened for infection. Ecological Niche Models (ENMs) were computed for species of rodent and their association with crop-growing areas. We found 13 species of sandflies, several of which are first records for this region. Medically important species such as Lutzomyia anthophora, Lutzomyia diabolica, Lutzomyia cruciata, and Lutzomyia shannoni were documented. Leishmania spp. infection was not detected in sandflies. Nine species of rodents were recorded, and Leishmania (Leishmania) mexicana infection was found in four species of Peromyscus and Sigmodon. ENMs showed that potential distribution of rodent pest species overlaps with allocated crop areas. This shows that Leishmania (L.) mexicana infection is present in the Northeastern region of Mexico, and that previously unrecorded sandfly species occur in the same areas. These findings suggest a potential risk of transmission of Leishmania (L.) mexicana. PMID:28825400

  19. Purification, structural characterization and anticoagulant properties of fucosylated chondroitin sulfate isolated from Holothuria mexicana.

    PubMed

    Mou, Jiaojiao; Wang, Cong; Li, Wenjing; Yang, Jie

    2017-05-01

    A novel fucosylated chondroitin sulfate (HmG) was isolated from sea cucumber Holothuria mexicana, the structure of which was characterized by monosaccharide composition, disaccharide composition, IR, 1 H and 13 C NMR spectrum, additionally with two dimensional NMR spectrum of degraded HmG (DHmG). The backbone of HmG was identified as chondroitin 6-O sulfate, while the major O-4 sulfated fucose branches linked to O-3 position of glucuronic acid in almost every disaccharide unit. The anticoagulant activities of HmG and DHmG were assessed and compared with heparin and low molecular weight heparin. The results indicated that HmG and DHmG both could significantly prolong the activated partial thrombo-plastin time, and the properties were well related to its molecular weight. DHmG showed similar anticoagulant properties to low molecular weight heparin with less bleeding risks, making it a safer anticoagulant drug. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. 2'-Deoxyribosyltransferase from Leishmania mexicana, an efficient biocatalyst for one-pot, one-step synthesis of nucleosides from poorly soluble purine bases.

    PubMed

    Crespo, N; Sánchez-Murcia, P A; Gago, F; Cejudo-Sanches, J; Galmes, M A; Fernández-Lucas, Jesús; Mancheño, José Miguel

    2017-10-01

    Processes catalyzed by enzymes offer numerous advantages over chemical methods although in many occasions the stability of the biocatalysts becomes a serious concern. Traditionally, synthesis of nucleosides using poorly water-soluble purine bases, such as guanine, xanthine, or hypoxanthine, requires alkaline pH and/or high temperatures in order to solubilize the substrate. In this work, we demonstrate that the 2'-deoxyribosyltransferase from Leishmania mexicana (LmPDT) exhibits an unusually high activity and stability under alkaline conditions (pH 8-10) across a broad range of temperatures (30-70 °C) and ionic strengths (0-500 mM NaCl). Conversely, analysis of the crystal structure of LmPDT together with comparisons with hexameric, bacterial homologues revealed the importance of the relationships between the oligomeric state and the active site architecture within this family of enzymes. Moreover, molecular dynamics and docking approaches provided structural insights into the substrate-binding mode. Biochemical characterization of LmPDT identifies the enzyme as a type I NDT (PDT), exhibiting excellent activity, with specific activity values 100- and 4000-fold higher than the ones reported for other PDTs. Interestingly, LmPDT remained stable during 36 h at different pH values at 40 °C. In order to explore the potential of LmPDT as an industrial biocatalyst, enzymatic production of several natural and non-natural therapeutic nucleosides, such as vidarabine (ara A), didanosine (ddI), ddG, or 2'-fluoro-2'-deoxyguanosine, was carried out using poorly water-soluble purines. Noteworthy, this is the first time that the enzymatic synthesis of 2'-fluoro-2'-deoxyguanosine, ara G, and ara H by a 2'-deoxyribosyltransferase is reported.

  1. In vitro activity of synthetic tetrahydroindeno[2,1-c]quinolines on Leishmania mexicana.

    PubMed

    Hernández-Chinea, Concepción; Carbajo, Erika; Sojo, Felipe; Arvelo, Francisco; Kouznetsov, Vladimir V; Romero-Bohórquez, Arnold R; Romero, Pedro J

    2015-12-01

    New synthetic compounds based on tetrahydroindenoquinoline structure were evaluated for their in vitro antileishmanial activities. The seven compounds assayed have antiproliferative activities against promastigotes of Leishmania mexicana. Compound 1 and 3 were the most active (IC50 1.0 μg/ml) and showed high selectivity towards the parasite. These compounds were selected to evaluate their effect on promastigote morphology and mitochondrial transmembrane potential as well as on the amastigote capability to survive into macrophages J774 cell line. Whereas compound 1 affected the promastigote cell cycle, compound 3 induced morphological changes and the total collapse of the mitochondrial transmembrane potential, a hallmark of apoptosis. Both compounds also affected the amastigote form of the parasite, decreasing their survival rate in J774 macrophages. Due to the greatest selectivity index, the apparent effect as apoptotic inducer and its sustained inhibition on intracellular amastigote replication, compound 3 is the best candidate to be tested in vivo. This compound is worth considering for the development of new antileishmanial drugs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Molecular Characterization, Expression and in vivo Analysis of LmexCht1: the Chitinase of the Human Pathogen, Leishmania mexicana

    PubMed Central

    Joshi, Manju B.; Rogers, Matthew E.; Shakarian, Alison M.; Yamage, Mat; Al-Harthi, Saeed A.; Bates, Paul A.; Dwyer, Dennis M.

    2010-01-01

    SUMMARY Chitinases have been implicated to be of importance in the life cycle development and transmission of a variety of parasitic organisms. Using a molecular approach, we identified and characterized the structure of a single copy LmexCht1-chitinase gene from the primitive trypanosomatid pathogen of humans, Leishmania mexicana. The LmexCht1 encodes an ~50 kDa protein, with well-conserved substrate-binding and catalytic domains characteristic of members of the Chitinase-18 protein family. Further, we showed that LmexCht1 mRNA is constitutively expressed by both the insect vector (i.e. promastigote) and mammalian (i.e. amastigote) life cycle developmental forms of this protozoan parasite. Interestingly, however, amastigotes were found to secrete/release ~ >2-4 fold higher levels of chitinase activity during their growth in vitro than promastigotes. Moreover, a homologous episomal-expression system was devised and used to express an epitope–tagged LmexCht1 chimeric construct in these parasites. Expression of the LmexCht1 chimera was verified in these transfectants by RT-PCR, Western blots and indirect immunofluorescence analyses. Further, results of coupled-immunoprecipitation/ enzyme activity experiments demonstrated that the LmexCht1 chimeric protein was secreted/released by these transfected L. mexicana parasites and that it possessed functional chitinase enzyme activity. Such transfectants were also evaluated for their infectivity both in human macrophages in vitro and in two different strains of mice. Results of those experiments demonstrated that the LmexCht1 transfectants survived significantly better in human macrophages and also produced significantly larger lesions in mice than control parasites. Taken together, our results indicate that the LmexCht1-chimera afforded a definitive survival advantage to the parasite within these mammalian hosts. Thus, the LmexCht1 could potentially represent a new virulence determinant in the mammalian phase of this

  3. Leishmania mexicana differentiation involves a selective plasma membrane autophagic-like process.

    PubMed

    Dagger, Francehuli; Bengio, Camila; Martinez, Angel; Ayesta, Carlos

    2017-11-23

    Parasites of the Leishmania genus, which are the causative agents of leishmaniasis, display a complex life cycle, from a flagellated form (promastigotes) residing in the midgut of the phlebotomine vector to a non-flagellated form (amastigote) invading the mammalian host. The cellular process for the conversion between these forms is an interesting biological phenomenon involving modulation of the plasma membrane. In this study, we describe a selective autophagic-like process during the in vitro differentiation of Leishmania mexicana promastigote to amastigote-like cells. This process is responsible for size reduction and shape change of the promastigote (15-20 μm long) to the rounded amastigote-like form (4-5 μm long), identical to the one that infects host macrophages. This autophagic-like process is characterized by a profound folding of the plasma membrane and the presence of abundant cytoplasmic lipid droplets that may be the product of changes in the lipid metabolism. The key feature for the differentiation process at either pH 7.0 or pH 5.5 is the shift in temperature from 25 to 35 °C. Flagella shortening during the differentiation process appears as the product of continuous flagellar microtubular disassembly that is also accompanied by changes in mitochondrion localization. Drugs directed at blocking the parasite autophagic-like process could be important as new strategies to fight the disease.

  4. Forty-two years of Revista Mexicana de Astronomía y Astrofísica: Some history and musings on the future

    NASA Astrophysics Data System (ADS)

    Allen, C.; Torres-Peimbert, S.

    2017-07-01

    After 42 years of continuously publishing the Revista Mexicana de Astronomía y Astrofísica, we cast a short retrospective view on its history and we share our plans for the future. RMxAA was founded in 1974. Founding editors were P. Pishmish, E. Mendoza and S. Torres-Peimbert. RMxAA has published original research papers in all areas of astronomy, astrophysics and related fields. Until 1994 RMxAA also published the proceedings of astronomical conferences held in México and Latin America. Since 1995 a Series devoted exclusively to such proceedings was founded, RMxAC, Revista Mexicana de Astronomía y Astrofísica (Serie de Conferencias). All papers submitted to RMxAA are sent to internationally recognized experts to be strictly refereed. RMxAA is included in Current Contents, Science Citation Index and other relevant international indexes. Both publications are fully integrated into the ADS. Their contents have always been freely available to the general public. All this ensures a wide international visibility, comparable to that of the best astronomical journals. The impact factor of RMxAA has varied over the years, mostly as a consequence of small number statistics. The average impact factor is about 2.4, far larger than that of all but a few Latin American scientific journals. The editorial independence of RMxAA, the fact that there are no page charges for authors, and that the printed version is distributed free of charge to astronomical libraries all over the world motivate us to look forward with optimism to many more years of publication. In view of recent developments in the scientific publishing field, we have applied to obtain the DOI for the published papers, and are in the process of becoming an all-electronic publication.

  5. Sporothrix brasiliensis, S. globosa, and S. mexicana, Three New Sporothrix Species of Clinical Interest▿

    PubMed Central

    Marimon, Rita; Cano, Josep; Gené, Josepa; Sutton, Deanna A.; Kawasaki, Masako; Guarro, Josep

    2007-01-01

    Sporothrix schenckii is the species responsible for sporotrichosis, a fungal infection caused by the traumatic implantation of this dimorphic fungus. Recent molecular studies have demonstrated that this species constitutes a complex of numerous phylogenetic species. Since the delineation of such species could be of extreme importance from a clinical point of view, we have studied a total of 127 isolates, most of which were received as S. schenckii, including the available type strains of species currently considered synonyms, and also some close morphological species. We have phenotypically characterized all these isolates using different culture media, growth rates at different temperatures, and numerous nutritional tests and compared their calmodulin gene sequences. The molecular analysis revealed that Sporothrix albicans, S. inflata, and S. schenckii var. luriei are species that are clearly different from S. schenckii. The combination of these phenetic and genetic approaches allowed us to propose the new species Sporothrix brasiliensis, S. globosa, and S. mexicana. The key phenotypic features for recognizing these species are the morphology of the sessile pigmented conidia, growth at 30, 35, and 37°C, and the assimilation of sucrose, raffinose, and ribitol. PMID:17687013

  6. A novel Zea mays ssp. mexicana L. MYC-type ICE-like transcription factor gene ZmmICE1, enhances freezing tolerance in transgenic Arabidopsis thaliana.

    PubMed

    Lu, Xiang; Yang, Lei; Yu, Mengyuan; Lai, Jianbin; Wang, Chao; McNeil, David; Zhou, Meixue; Yang, Chengwei

    2017-04-01

    The annual Zea mays ssp. mexicana L., a member of the teosinte group, is a close wild relative of maize and thus can be effectively used in maize improvement. In this study, an ICE-like gene, ZmmICE1, was isolated from a cDNA library of RNA-Seq from cold-treated seedling tissues of Zea mays ssp. mexicana L. The deduced protein of ZmmICE1 contains a highly conserved basic helix-loop-helix (bHLH) domain and C-terminal region of ICE-like proteins. The ZmmICE1 protein localizes to the nucleus and shows sumoylation when expressed in an Escherichia coli reconstitution system. In addition, yeast one hybrid assays indicated that ZmmICE1 has transactivation activities. Moreover, ectopic expression of ZmmICE1 in the Arabidopsis ice1-2 mutant increased freezing tolerance. The ZmmICE1 overexpressed plants showed lower electrolyte leakage (EL), reduced contents of malondialdehyde (MDA). The expression of downstream cold related genes of Arabidopsis C-repeat-binding factors (AtCBF1, AtCBF2 and AtCBF3), cold-responsive genes (AtCOR15A and AtCOR47), kinesin-1 member gene (AtKIN1) and responsive to desiccation gene (AtRD29A) was significantly induced when compared with wild type under low temperature treatment. Taken together, these results indicated that ZmmICE1 is the homolog of Arabidopsis inducer of CBF expression genes (AtICE1/2) and plays an important role in the regulation of freezing stress response. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  7. Isopropyl quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives induce regulated necrosis-like cell death on Leishmania (Leishmania) mexicana.

    PubMed

    Chacón-Vargas, Karla Fabiola; Andrade-Ochoa, Sergio; Nogueda-Torres, Benjamín; Juárez-Ramírez, Dulce Carolina; Lara-Ramírez, Edgar E; Mondragón-Flores, Ricardo; Monge, Antonio; Rivera, Gildardo; Sánchez-Torres, Luvia Enid

    2018-01-01

    Leishmaniasis is a neglected tropical disease caused by the parasite of the genus Leishmania. About 13 million people are infected worldwide, and it is estimated that 350 million are at risk of infection. Clinical manifestations depend on the parasite species and factors related to the host such as the immune system, nutrition, housing, and financial resources. Available treatments have severe side effects; therefore, research currently focuses on finding more active and less toxic compounds. Quinoxalines have been described as promising alternatives. In this context, 17 isopropyl quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives were evaluated as potential leishmanicidal agents. Their effect on the cell metabolism of Leishmania mexicana promastigotes and their cytotoxic effects on the J774.A1 cell line and on erythrocytes were evaluated, and their selectivity index was calculated. Compounds T-069 (IC 50  = 1.49 μg/mL), T-070 (IC 50  = 1.71 μg/mL), T-072 (IC 50  = 6.62 μg/mL), T-073 (IC 50  = 1.25 μg/mL), T-085 (IC 50  = 0.74 μg/mL), and T-116 (IC 50  = 0.88 μg/mL) were the most active against L. mexicana promastigotes and their mechanism of action was characterized by flow cytometry and microscopy. Compound T-073, the most selective quinoxaline derivative, induced cell membrane damage, phosphatidylserine exposition, reactive oxygen species production, disruption of the mitochondrion membrane potential, and DNA fragmentation, all in a dose-dependent manner, indicating the induction of regulated necrosis. Light and transmission electron microscopy showed the drastic morphological changes induced and the mitochondrion as the most sensitive organelle in response to T-073. This study describes the mechanism by which active isopropyl quinoxaline-7-carboxylate 1,4-di-N-oxide quinoxalines affect the parasite.

  8. Microhabitat use, population densities, and size distributions of sulfur cave-dwelling Poecilia mexicana

    PubMed Central

    Bierbach, David; Riesch, Rüdiger; Schießl, Angela; Wigh, Adriana; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Klaus, Sebastian; Zimmer, Claudia; Plath, Martin

    2014-01-01

    The Cueva del Azufre in Tabasco, Mexico, is a nutrient-rich cave and its inhabitants need to cope with high levels of dissolved hydrogen sulfide and extreme hypoxia. One of the successful colonizers of this cave is the poeciliid fish Poecilia mexicana, which has received considerable attention as a model organism to examine evolutionary adaptations to extreme environmental conditions. Nonetheless, basic ecological data on the endemic cave molly population are still missing; here we aim to provide data on population densities, size class compositions and use of different microhabitats. We found high overall densities in the cave and highest densities at the middle part of the cave with more than 200 individuals per square meter. These sites have lower H2S concentrations compared to the inner parts where most large sulfide sources are located, but they are annually exposed to a religious harvesting ceremony of local Zoque people called La Pesca. We found a marked shift in size/age compositions towards an overabundance of smaller, juvenile fish at those sites. We discuss these findings in relation to several environmental gradients within the cave (i.e., differences in toxicity and lighting conditions), but we also tentatively argue that the annual fish harvest during a religious ceremony (La Pesca) locally diminishes competition (and possibly, cannibalism by large adults), which is followed by a phase of overcompensation of fish densities. PMID:25083351

  9. Microhabitat use, population densities, and size distributions of sulfur cave-dwelling Poecilia mexicana.

    PubMed

    Jourdan, Jonas; Bierbach, David; Riesch, Rüdiger; Schießl, Angela; Wigh, Adriana; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Klaus, Sebastian; Zimmer, Claudia; Plath, Martin

    2014-01-01

    The Cueva del Azufre in Tabasco, Mexico, is a nutrient-rich cave and its inhabitants need to cope with high levels of dissolved hydrogen sulfide and extreme hypoxia. One of the successful colonizers of this cave is the poeciliid fish Poecilia mexicana, which has received considerable attention as a model organism to examine evolutionary adaptations to extreme environmental conditions. Nonetheless, basic ecological data on the endemic cave molly population are still missing; here we aim to provide data on population densities, size class compositions and use of different microhabitats. We found high overall densities in the cave and highest densities at the middle part of the cave with more than 200 individuals per square meter. These sites have lower H2S concentrations compared to the inner parts where most large sulfide sources are located, but they are annually exposed to a religious harvesting ceremony of local Zoque people called La Pesca. We found a marked shift in size/age compositions towards an overabundance of smaller, juvenile fish at those sites. We discuss these findings in relation to several environmental gradients within the cave (i.e., differences in toxicity and lighting conditions), but we also tentatively argue that the annual fish harvest during a religious ceremony (La Pesca) locally diminishes competition (and possibly, cannibalism by large adults), which is followed by a phase of overcompensation of fish densities.

  10. Validated liquid chromatographic method and analysis of content of tilianin on several extracts obtained from Agastache mexicana and its correlation with vasorelaxant effect.

    PubMed

    Hernández-Abreu, Oswaldo; Durán-Gómez, Liliana; Best-Brown, Roberto; Villalobos-Molina, Rafael; Rivera-Leyva, Julio; Estrada-Soto, Samuel

    2011-11-18

    To optimize the obtention of tilianin, an antihypertensive flavonoid isolated from Agastache mexicana (Lamiaceae), a medicinal plant used in Mexico for the treatment of hypertension. Also, a validated HPLC method to quantify tilianin from different extracts, obtained by several extraction methods, was developed. The aerial parts of Agastache mexicana were dried at different temperatures (22, 40, 50, 90, 100 and 180°C) and the dry material was extracted with methanol by maceration to compare the content of the active constituent tilianin in the samples. Furthermore, EtOH:H(2)O (7:3), infusion and decoction extracts were prepared from air-dried samples at room temperature to compare the content and composition of the different extraction methods. Moreover, an ex vivo vasorelaxant test on endothelium-intact aortic rat rings was conducted, in order to correlate the presence of tilianin with the activity of each extract. Higher concentration and amounts of tilianin were determined from chromatograms in the obtained methanolic extracts from plant material dried at 90, 50, 40 and 22°C, followed by 100°C; however, lower concentrations were observed in dried at 180°C and EtOH:H(2)O (7:3). It is worth to notice that methanolic extracts with higher amount of tilianin were the most potent vasorelaxant extracts, even though these extracts were less potent than carbachol, a positive control used. Finally, decoction, infusion and EtOH:H(2)O (7:3) extracts did not show any vasorelaxant effect. Results suggest that extracts with higher concentration of tilianin possess the best vasorelaxant activity, which allowed us to have a HPLC method for future quality control for this medicinal plant. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  11. Sex-specific local life-history adaptation in surface- and cave-dwelling Atlantic mollies (Poecilia mexicana).

    PubMed

    Riesch, Rüdiger; Reznick, David N; Plath, Martin; Schlupp, Ingo

    2016-03-10

    Cavefishes have long been used as model organisms showcasing adaptive diversification, but does adaptation to caves also facilitate the evolution of reproductive isolation from surface ancestors? We raised offspring of wild-caught surface- and cave-dwelling ecotypes of the neotropical fish Poecilia mexicana to sexual maturity in a 12-month common garden experiment. Fish were raised under one of two food regimes (high vs. low), and this was crossed with differences in lighting conditions (permanent darkness vs. 12:12 h light:dark cycle) in a 2 × 2 factorial design, allowing us to elucidate potential patterns of local adaptation in life histories. Our results reveal a pattern of sex-specific local life-history adaptation: Surface molly females had the highest fitness in the treatment best resembling their habitat of origin (high food and a light:dark cycle), and suffered from almost complete reproductive failure in darkness, while cave molly females were not similarly affected in any treatment. Males of both ecotypes, on the other hand, showed only weak evidence for local adaptation. Nonetheless, local life-history adaptation in females likely contributes to ecological diversification in this system and other cave animals, further supporting the role of local adaptation due to strong divergent selection as a major force in ecological speciation.

  12. Sex-specific local life-history adaptation in surface- and cave-dwelling Atlantic mollies (Poecilia mexicana)

    PubMed Central

    Riesch, Rüdiger; Reznick, David N.; Plath, Martin; Schlupp, Ingo

    2016-01-01

    Cavefishes have long been used as model organisms showcasing adaptive diversification, but does adaptation to caves also facilitate the evolution of reproductive isolation from surface ancestors? We raised offspring of wild-caught surface- and cave-dwelling ecotypes of the neotropical fish Poecilia mexicana to sexual maturity in a 12-month common garden experiment. Fish were raised under one of two food regimes (high vs. low), and this was crossed with differences in lighting conditions (permanent darkness vs. 12:12 h light:dark cycle) in a 2 × 2 factorial design, allowing us to elucidate potential patterns of local adaptation in life histories. Our results reveal a pattern of sex-specific local life-history adaptation: Surface molly females had the highest fitness in the treatment best resembling their habitat of origin (high food and a light:dark cycle), and suffered from almost complete reproductive failure in darkness, while cave molly females were not similarly affected in any treatment. Males of both ecotypes, on the other hand, showed only weak evidence for local adaptation. Nonetheless, local life-history adaptation in females likely contributes to ecological diversification in this system and other cave animals, further supporting the role of local adaptation due to strong divergent selection as a major force in ecological speciation. PMID:26960566

  13. Acarine infracommunities associated with the Mexican free-tailed bat, Tadarida brasiliensis mexicana (Chiroptera: Molossidae) in arid regions of Mexico.

    PubMed

    Guzmán-Cornejo, C; García-Prieto, L; Morales-Malacara, J B; Pérez-Ponce De León, G

    2003-11-01

    The Mexican free-tailed bat, Tadarida brasiliensis mexicana, is one of the most widely distributed bats, and its range includes the whole Mexican territory. Ectoparasites of this bat have been the subject of isolated reports, but no studies of its community ecology have been conducted. The acarine infracommunities associated with this bat were analyzed, comparing bat populations from three arid regions of Mexico: an abandoned factory in Nombre de Dios, Durango; a cave in Santiago, Nuevo León; and a church in Concepción del Oro, Zacatecas. The acarine infracommunity in Nuevo Le6n's bats exhibited the highest levels of diversity as reflected by a higher richness, a lower dominance, and a moderate and relatively homogeneous abundance in this locality in relation to the other two. This pattern is influenced by stable cave conditions relative to artificial habitats. Notwithstanding, further studies are required to determine whether or not different habitat conditions are a primary factor in the process of structuring the acari infracommunities.

  14. Cheminformatic models based on machine learning for pyruvate kinase inhibitors of Leishmania mexicana.

    PubMed

    Jamal, Salma; Scaria, Vinod

    2013-11-19

    Leishmaniasis is a neglected tropical disease which affects approx. 12 million individuals worldwide and caused by parasite Leishmania. The current drugs used in the treatment of Leishmaniasis are highly toxic and has seen widespread emergence of drug resistant strains which necessitates the need for the development of new therapeutic options. The high throughput screen data available has made it possible to generate computational predictive models which have the ability to assess the active scaffolds in a chemical library followed by its ADME/toxicity properties in the biological trials. In the present study, we have used publicly available, high-throughput screen datasets of chemical moieties which have been adjudged to target the pyruvate kinase enzyme of L. mexicana (LmPK). The machine learning approach was used to create computational models capable of predicting the biological activity of novel antileishmanial compounds. Further, we evaluated the molecules using the substructure based approach to identify the common substructures contributing to their activity. We generated computational models based on machine learning methods and evaluated the performance of these models based on various statistical figures of merit. Random forest based approach was determined to be the most sensitive, better accuracy as well as ROC. We further added a substructure based approach to analyze the molecules to identify potentially enriched substructures in the active dataset. We believe that the models developed in the present study would lead to reduction in cost and length of clinical studies and hence newer drugs would appear faster in the market providing better healthcare options to the patients.

  15. Gluconeogenesis in Leishmania mexicana: contribution of glycerol kinase, phosphoenolpyruvate carboxykinase, and pyruvate phosphate dikinase.

    PubMed

    Rodriguez-Contreras, Dayana; Hamilton, Nicklas

    2014-11-21

    Gluconeogenesis is an active pathway in Leishmania amastigotes and is essential for their survival within the mammalian cells. However, our knowledge about this pathway in trypanosomatids is very limited. We investigated the role of glycerol kinase (GK), phosphoenolpyruvate carboxykinase (PEPCK), and pyruvate phosphate dikinase (PPDK) in gluconeogenesis by generating the respective Leishmania mexicana Δgk, Δpepck, and Δppdk null mutants. Our results demonstrated that indeed GK, PEPCK, and PPDK are key players in the gluconeogenesis pathway in Leishmania, although stage-specific differences in their contribution to this pathway were found. GK participates in the entry of glycerol in promastigotes and amastigotes; PEPCK participates in the entry of aspartate in promastigotes, and PPDK is involved in the entry of alanine in amastigotes. Furthermore, the majority of alanine enters into the pathway via decarboxylation of pyruvate in promastigotes, whereas pathway redundancy is suggested for the entry of aspartate in amastigotes. Interestingly, we also found that l-lactate, an abundant glucogenic precursor in mammals, was used by Leishmania amastigotes to synthesize mannogen, entering the pathway through PPDK. On the basis of these new results, we propose a revision in the current model of gluconeogenesis in Leishmania, emphasizing the differences between amastigotes and promastigotes. This work underlines the importance of studying the trypanosomatid intracellular life cycle stages to gain a better understanding of the pathologies caused in humans. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. Agemone mexicana flavanones; apposite inverse agonists of the β2-adrenergic receptor in asthma treatment.

    PubMed

    Eniafe, Gabriel O; Metibemu, Damilohun S; Omotuyi, Olaposi I; Ogunleye, Adewale J; Inyang, Olumide K; Adelakun, Niyi S; Adeniran, Yakubu O; Adewumi, Bamidele; Enejoh, Ojochenemi A; Osunmuyiwa, Joseph O; Shodehinde, Sidiqat A; Oyeneyin, Oluwatoba E

    2018-01-01

    Asthma is an inflammatory disease of the airway that poses a major threat to human health. With increase industrialization in the developed and developing countries, the incidence of asthma is on the rise. The β2-adrenergic receptor is an important target in designing anti-asthmatic drugs. The synthetic agonists of the β2-adrenergic receptor used over the years proved effective, but with indispensable side effects, thereby limiting their therapeutic use on a long-term scale. Inverse agonists of this receptor, although initially contraindicated, had been reported to have long-term beneficial effects. Phytochemicals from Agemone mexicana were screened against the human β2-adrenergic receptor in the agonist, inverse agonist, covalent agonist, and the antagonist conformations. Molecular docking of the phyto-constituents showed that the plant constituents bind better to the inverse agonist bound conformation of the protein, and revealed two flavanones; eriodictyol and hesperitin, with lower free energy (ΔG) values and higher affinities to the inverse agonist bound receptor than the co-crystallized ligand. Eriodictyol and hesperitin bind with the glide score of -10.684 and - 9.958 kcal/mol respectively, while the standard compound ICI-118551, binds with glide score of -9.503 kcal/mol. Further interaction profiling at the protein orthosteric site and ADME/Tox screening confirmed the drug-like properties of these compounds.

  17. A Study on Intraspecific Resource Partitioning in the Stingless bee Scaptotrigona mexicana Guérin (Apidae, Meliponini) Using Behavioral and Molecular Techniques.

    PubMed

    Sánchez, D; Solórzano-Gordillo, E; Vandame, R

    2016-10-01

    As a general rule, within an ecological guild, there is one species that is dominant and is commonly the most abundant. The aim of this work was to investigate if such pattern occurs intraspecifically, among colonies of the stingless bee Scaptotrigona mexicana Guérin. Through behavioral and molecular techniques, we found preliminary evidence that apparently colonies of this species do not monopolize resources, instead they seem to share food; however, some colonies had more foragers in a food patch or in a feeder, so some type of exclusion could be at work, though we could not determine the final output of such interaction, i.e., if underrepresented colonies were eventually excluded, developed slower or were overrepresented in other food patches. Our results give evidence that resource partitioning within this species occurs peacefully; however, further studies are necessary to determine if threatening behavior or aggressions appear when resources are scarce and competition becomes harsher.

  18. Caesalpina pulcherrima (L.) Sw.

    Treesearch

    Nadia Navarrete-Tindall

    2002-01-01

    Caesalpina pulcherrima, is native to the West Indies and Mexico (Croat 1978) and has naturalized in El Salvador and Panama. Two similar species are the Mexican bird of paradise C. mexicana, and bird of paradise bush C. gilliesi.

  19. Ensemble-based ADME-Tox profiling and virtual screening for the discovery of new inhibitors of the Leishmania mexicana cysteine protease CPB2.8ΔCTE.

    PubMed

    Scala, Angela; Rescifina, Antonio; Micale, Nicola; Piperno, Anna; Schirmeister, Tanja; Maes, Louis; Grassi, Giovanni

    2018-02-01

    In an effort to identify novel molecular warheads able to inhibit Leishmania mexicana cysteine protease CPB2.8ΔCTE, fused benzo[b]thiophenes and β,β'-triketones emerged as covalent inhibitors binding the active site cysteine residue. Enzymatic screening showed a moderate-to-excellent activity (12%-90% inhibition of the target enzyme at 20 μm). The most promising compounds were selected for further profiling including in vitro cell-based assays and docking studies. Computational data suggest that benzo[b]thiophenes act immediately as non-covalent inhibitors and then as irreversible covalent inhibitors, whereas a reversible covalent mechanism emerged for the 1,3,3'-triketones with a Y-topology. Based on the predicted physicochemical and ADME-Tox properties, compound 2b has been identified as a new drug-like, non-mutagen, non-carcinogen, and non-neurotoxic lead candidate. © 2017 John Wiley & Sons A/S.

  20. Variation in ectomycorrhizal fungal communities associated with Oreomunnea mexicana (Juglandaceae) in a Neotropical montane forest.

    PubMed

    Corrales, Adriana; Arnold, A Elizabeth; Ferrer, Astrid; Turner, Benjamin L; Dalling, James W

    2016-01-01

    Neotropical montane forests are often dominated by ectomycorrhizal (EM) tree species, yet the diversity of their EM fungal communities remains poorly explored. In lower montane forests in western Panama, the EM tree species Oreomunnea mexicana (Juglandaceae) forms locally dense populations in forest otherwise characterized by trees that form arbuscular mycorrhizal (AM) associations. The objective of this study was to compare the composition of EM fungal communities associated with Oreomunnea adults, saplings, and seedlings across sites differing in soil fertility and the amount and seasonality of rainfall. Analysis of fungal nrITS DNA (nuclear ribosomal internal transcribed spacers) revealed 115 EM fungi taxa from 234 EM root tips collected from adults, saplings, and seedlings in four sites. EM fungal communities were equally species-rich and diverse across Oreomunnea developmental stages and sites, regardless of soil conditions or rainfall patterns. However, ordination analysis revealed high compositional turnover between low and high fertility/rainfall sites located ca. 6 km apart. The EM fungal community was dominated by Russula (ca. 36 taxa). Cortinarius, represented by 14 species and previously reported to extract nitrogen from organic sources under low nitrogen availability, was found only in low fertility/high rainfall sites. Phylogenetic diversity analyses of Russula revealed greater evolutionary distance among taxa found on sites with contrasting fertility and rainfall than was expected by chance, suggesting that environmental differences among sites may be important in structuring EM fungal communities. More research is needed to evaluate whether EM fungal taxa associated with Oreomunnea form mycorrhizal networks that might account for local dominance of this tree species in otherwise diverse forest communities.

  1. Argemone mexicana decoction versus artesunate-amodiaquine for the management of malaria in Mali: policy and public-health implications.

    PubMed

    Graz, Bertrand; Willcox, Merlin L; Diakite, Chiaka; Falquet, Jacques; Dackuo, Florent; Sidibe, Oumar; Giani, Sergio; Diallo, Drissa

    2010-01-01

    A classic way of delaying drug resistance is to use an alternative when possible. We tested the malaria treatment Argemone mexicana decoction (AM), a validated self-prepared traditional medicine made with one widely available plant and safe across wide dose variations. In an attempt to reflect the real situation in the home-based management of malaria in a remote Malian village, 301 patients with presumed uncomplicated malaria (median age 5 years) were randomly assigned to receive AM or artesunate-amodiaquine [artemisinin combination therapy (ACT)] as first-line treatment. Both treatments were well tolerated. Over 28 days, second-line treatment was not required for 89% (95% CI 84.1-93.2) of patients on AM, versus 95% (95% CI 88.8-98.3) on ACT. Deterioration to severe malaria was 1.9% in both groups in children aged 5 years) and 0% had coma/convulsions. AM, now government-approved in Mali, could be tested as a first-line complement to standard modern drugs in high-transmission areas, in order to reduce the drug pressure for development of resistance to ACT, in the management of malaria. In view of the low rate of severe malaria and good tolerability, AM may also constitute a first-aid treatment when access to other antimalarials is delayed.

  2. Anticonvulsant and Antioxidant Effects of Tilia americana var. mexicana and Flavonoids Constituents in the Pentylenetetrazole-Induced Seizures

    PubMed Central

    Cárdenas-Rodríguez, Noemí; González-Trujano, María Eva; Aguirre-Hernández, Eva; Ruíz-García, Matilde; Sampieri, Aristides; Coballase-Urrutia, Elvia; Carmona-Aparicio, Liliana

    2014-01-01

    Tilia genus is commonly used around the world for its central nervous system properties; it is prepared as tea and used as tranquilizing, anticonvulsant, and analgesic. In this study, anticonvulsant activity of the Tilia americana var. mexicana inflorescences and leaves was investigated by evaluating organic and aqueous extracts (100, 300, and 600 mg/kg, i.p.) and some flavonoids in the pentylenetetrazole-induced seizures in mice. Moreover, antioxidant effect of these extracts and flavonoids was examined in an in vitro study by using spectrophotometric technique. Significant activity was observed in the methanol extract from inflorescences. An HPLC analysis of the methanol extract from inflorescences and leaves of Tilia allowed demonstrating the respective presence of some partial responsible flavonoid constituents: quercetin (20.09 ± 1.20 μg/mg and 3.39 ± 0.10 μg/mg), rutin (3.52 ± 0.21 μg/mg and 8.94 ± 0.45 μg/mg), and isoquercitrin (1.74 ± 0.01 μg/mg and 1.24 ± 0.13 μg/mg). In addition, significant but different antioxidant properties were obtained among the flavonoids and the extracts investigated. Our results provide evidence of the anticonvulsant activity of Tilia reinforcing its utility for central nervous system diseases whose mechanism of action might involve partial antioxidant effects due to the presence of flavonoids. PMID:25197430

  3. Assessing the importance of four sandfly species (Diptera: Psychodidae) as vectors of Leishmania mexicana in Campeche, Mexico.

    PubMed

    Pech-May, A; Peraza-Herrera, G; Moo-Llanes, D A; Escobedo-Ortegón, J; Berzunza-Cruz, M; Becker-Fauser, I; Montes DE Oca-Aguilar, A C; Rebollar-Téllez, E A

    2016-09-01

    Localized cutaneous leishmaniasis represents a public health problem in many areas of Mexico, especially in the Yucatan Peninsula. An understanding of vector ecology and bionomics is of great importance in evaluations of the transmission dynamics of Leishmania parasites. A field study was conducted in the county of Calakmul, state of Campeche, during the period from November 2006 to March 2007. Phlebotomine sandfly vectors were sampled using Centers for Disease Control light traps, baited Disney traps and Shannon traps. A total of 3374 specimens were captured in the two villages of Once de Mayo (93.8%) and Arroyo Negro (6.1%). In Once de Mayo, the most abundant species were Psathyromyia shannoni, Lutzomyia cruciata, Bichromomyia olmeca olmeca and Psychodopygus panamensis (all: Diptera: Psychodidae). The Shannon trap was by far the most efficient method of collection. The infection rate, as determined by Leishmania mexicana-specific polymerase chain reaction, was 0.3% in Once de Mayo and infected sandflies included Psy. panamensis, B. o. olmeca and Psa. shannoni. There were significant differences in human biting rates across sandfly species and month of sampling. Ecological niche modelling analyses showed an overall overlap of 39.1% for the four species in the whole state of Campeche. In addition, the finding of nine vector-reservoir pairs indicates a potential interaction. The roles of the various sandfly vectors in Calakmul are discussed. © 2016 The Royal Entomological Society.

  4. Application of hydrostatic CCC-TLC-HPLC-ESI-TOF-MS for the bioguided fractionation of anticholinesterase alkaloids from Argemone mexicana L. roots.

    PubMed

    Kukula-Koch, Wirginia; Mroczek, Tomasz

    2015-03-01

    A rapid hydrostatic counter-current chromatography-thin-layer chromatography-electrospray-ionization time-of-flight mass spectrometry (CCC-TLC-ESI-TOF-MS) technique was established for use in seeking potent anti-Alzheimer's drugs among the acethylcholinesterase inhibitors in Argemone mexicana L. underground parts, with no need to isolate components in pure form. The dichloromethane extract from the roots of Mexican prickly poppy that was most rich in secondary metabolites was subjected to hydrostatic-CCC-based fractionation in descending mode, using a biphasic system composed of petroleum ether-ethyl acetate-methanol-water at the ratio of 1.5:3:2.1:2 (v/v). The obtained fractions were analyzed in a TLC-based AChE-inhibition "Fast Blue B" test. All active components in the fractions, including berberine, protopine, chelerithrine, sanguinarine, coptisine, palmatine, magnoflorine, and galanthamine, were identified in a direct TLC-HPLC-ESI-TOF-MS assay with high accuracy. This is the first time galanthamine has been reported in the extract of Mexican prickly poppy and the first time it has been identified in any member of the Papaveraceae family, in the significant quantity of 0.77%.

  5. Ecogeography of teosinte

    PubMed Central

    Sánchez González, José de Jesús; García, Guillermo Medina; Ojeda, Gabriela Ramírez; Larios, Lino De la Cruz; Holland, James Brendan; Medrano, Roberto Miranda; García Romero, Giovanni Emmanuel

    2018-01-01

    Adaptation of crops to climate change has motivated an increasing interest in the potential value of novel traits from wild species; maize wild relatives, the teosintes, harbor traits that may be useful to maize breeding. To study the ecogeographic distribution of teosinte we constructed a robust database of 2363 teosinte occurrences from published sources for the period 1842–2016. A geographical information system integrating 216 environmental variables was created for Mexico and Central America and was used to characterize the environment of each teosinte occurrence site. The natural geographic distribution of teosinte extends from the Western Sierra Madre of the State of Chihuahua, Mexico to the Pacific coast of Nicaragua and Costa Rica, including practically the entire western part of Mesoamerica. The Mexican annuals Zea mays ssp. parviglumis and Zea mays ssp. mexicana show a wide distribution in Mexico, while Zea diploperennis, Zea luxurians, Zea perennis, Zea mays ssp. huehuetenangensis, Zea vespertilio and Zea nicaraguensis had more restricted and distinct ranges, representing less than 20% of the total occurrences. Only 11.2% of teosinte populations are found in Protected Natural Areas in Mexico and Central America. Ecogeographical analysis showed that teosinte can cope with extreme levels of precipitation and temperatures during growing season. Modelling teosinte geographic distribution demonstrated congruence between actual and potential distributions; however, some areas with no occurrences appear to be within the range of adaptation of teosintes. Field surveys should be prioritized to such regions to accelerate the discovery of unknown populations. Potential areas for teosintes Zea mays ssp. mexicana races Chalco, Nobogame, and Durango, Zea mays ssp. huehuetenangensis, Zea luxurians, Zea diploperennis and Zea nicaraguensis are geographically separated; however, partial overlapping occurs between Zea mays ssp. parviglumis and Zea perennis, between Zea

  6. Is there a relationship between fledge age and nest temperature in Western Bluebirds (Sialia mexicana)?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Phillips, Emily Marie; Thompson, Brent E.; Hathcock, Charles Dean

    Extensive research has been done on temperature during bird incubation periods, but little has been done during nestling development, and to our knowledge, no studies have been done on Western Bluebird (Sialia mexicana) nestling development. In this study, dataloggers were used to monitor nest temperatures during the nestling development phase of Western Bluebirds to determine if there was a relationship between fledge age and temperature. The study was conducted in an existing nestbox network at Los Alamos National Laboratory and the surrounding area in north-central New Mexico. Based on the age of the nestlings at fledging, the nestboxes (n=65) weremore » split into three groups: early (16 and 17 days old, n=13), average (fledged at or between 18 and 20 days old, n=32), and late (21 days or older, n=20). The temperatures of the early and average (n=45) groups were not significantly different (p=0.32, W=3831000). There was a significant difference in the temperatures between the early and late groups (p=0.000, W=2965600). The early and average groups were then combined, tested against the late group, and were found to be significantly different (p=0.000, W=11315000). Analysis showed a difference within the first seven days post-hatch of 1.42°C between the early/average and late groupings. The results suggest that warmer nest temperatures during the nestling stage may influence the fledge date and may lead to faster fledging. There may be numerous explanations for this, such as a correlation with nestling development, and higher temperatures may allow for faster development. Brood size was non-significant and was not factored into the analysis. Future work should be directed in this area.« less

  7. Relation of desert pupfish abundance to selected environmental variables in natural and manmade habitats in the Salton Sea basin

    USGS Publications Warehouse

    Martin, B.A.; Saiki, M.K.

    2005-01-01

    We assessed the relation between abundance of desert pupfish, Cyprinodon macularius, and selected biological and physicochemical variables in natural and manmade habitats within the Salton Sea Basin. Field sampling in a natural tributary, Salt Creek, and three agricultural drains captured eight species including pupfish (1.1% of the total catch), the only native species encountered. According to Bray-Curtis resemblance functions, fish species assemblages differed mostly between Salt Creek and the drains (i.e., the three drains had relatively similar species assemblages). Pupfish numbers and environmental variables varied among sites and sample periods. Canonical correlation showed that pupfish abundance was positively correlated with abundance of western mosquitofish, Gambusia affinis, and negatively correlated with abundance of porthole livebearers, Poeciliopsis gracilis, tilapias (Sarotherodon mossambica and Tilapia zillii), longjaw mudsuckers, Gillichthys mirabilis, and mollies (Poecilia latipinnaandPoecilia mexicana). In addition, pupfish abundance was positively correlated with cover, pH, and salinity, and negatively correlated with sediment factor (a measure of sediment grain size) and dissolved oxygen. Pupfish abundance was generally highest in habitats where water quality extremes (especially high pH and salinity, and low dissolved oxygen) seemingly limited the occurrence of nonnative fishes. This study also documented evidence of predation by mudsuckers on pupfish. These findings support the contention of many resource managers that pupfish populations are adversely influenced by ecological interactions with nonnative fishes. ?? Springer 2005.

  8. Dynamic extrafloral nectar production: the timing of leaf damage affects the defensive response in Senna mexicana var. chapmanii (Fabaceae).

    PubMed

    Jones, Ian M; Koptur, Suzanne

    2015-01-01

    • Extrafloral nectar (EFN) mediates food for protection mutualisms between plants and defensive insects. Understanding sources of variation in EFN production is important because such variations may affect the number and identity of visitors and the effectiveness of plant defense. We investigated the influence of plant developmental stage, time of day, leaf age, and leaf damage on EFN production in Senna mexicana var. chapmanii. The observed patterns of variation in EFN production were compared with those predicted by optimal defense theory.• Greenhouse experiments with potted plants were conducted to determine how plant age, time of day, and leaf damage affected EFN production. A subsequent field study was conducted to determine how leaf damage, and the resulting increase in EFN production, affected ant visitation in S. chapmanii.• More nectar was produced at night and by older plants. Leaf damage resulted in increased EFN production, and the magnitude of the response was greater in plants damaged in the morning than those damaged at night. Damage to young leaves elicited a stronger defensive response than damage to older leaves, in line with optimal defense theory. Damage to the leaves of S. chapmanii also resulted in significantly higher ant visitation in the field.• Extrafloral nectar is an inducible defense in S. chapmanii. Developmental variations in its production support the growth differentiation balance hypothesis, while within-plant variations and damage responses support optimal defense theory. © 2015 Botanical Society of America, Inc.

  9. DIABETES MELLITUS COMO FACTOR DE RIESGO DE DEMENCIA EN LA POBLACIÓN ADULTA MAYOR MEXICANA

    PubMed Central

    Silvia, Mejía-Arango; Clemente, y Zúñiga-Gil

    2012-01-01

    Introduccion La diabetes mellitus y las demencias constituyen dos problemas crecientes de salud entre la población adulta mayor del mundo y en particular de los paises en desarrollo. Hacen falta estudios longitudinales sobre el papel de la diabetes como factor de riesgo para demencia. Objetivo Determinar el riesgo de demencia en sujetos Mexicanos con diabetes mellitus tipo 2. Materiales y Metodos Los sujetos diabéticos libres de demencia pertenecientes al Estudio Nacional de Salud y Envejecimiento en México fueron evaluados a los dos años de la línea de base. Se estudió el papel de los factores sociodemográficos, de otras comorbilidades y del tipo de tratamiento en la conversión a demencia. Resultados Durante la línea de base 749 sujetos (13.8%) tuvieron diabetes. El riesgo de desarrollar demencia en estos individuos fue el doble (RR, 2.08 IC 95%, 1.59–2.73). Se encontró un riesgo mayor en individuos de 80 años y más (RR 2.44 IC 95%, 1.46–4.08), en los hombres (RR, 2.25 IC 95%, 1.46–3.49) y en sujetos con nivel educativo menor de 7 años. El estar bajo tratamiento con insulina incrementó el riesgo de demencia (RR, 2.83, IC 95%, 1.58–5.06). Las otras comorbilidades que aumentaron el riesgo de demencia en los pacientes diabéticos fueron la hipertensión (RR, 2.75, IC 95%, 1.86–4.06) y la depresión (RR, 3.78, 95% IC 2.37–6.04). Conclusión Los sujetos con diabetes mellitus tienen un riesgo mayor de desarrollar demencia, La baja escolaridad y otras comorbilidades altamente prevalentes en la población Mexicana contribuyen a la asociación diabetes-demencia. PMID:21948010

  10. Comparative Life Cycle Transcriptomics Revises Leishmania mexicana Genome Annotation and Links a Chromosome Duplication with Parasitism of Vertebrates

    PubMed Central

    Fiebig, Michael; Kelly, Steven; Gluenz, Eva

    2015-01-01

    Leishmania spp. are protozoan parasites that have two principal life cycle stages: the motile promastigote forms that live in the alimentary tract of the sandfly and the amastigote forms, which are adapted to survive and replicate in the harsh conditions of the phagolysosome of mammalian macrophages. Here, we used Illumina sequencing of poly-A selected RNA to characterise and compare the transcriptomes of L. mexicana promastigotes, axenic amastigotes and intracellular amastigotes. These data allowed the production of the first transcriptome evidence-based annotation of gene models for this species, including genome-wide mapping of trans-splice sites and poly-A addition sites. The revised genome annotation encompassed 9,169 protein-coding genes including 936 novel genes as well as modifications to previously existing gene models. Comparative analysis of gene expression across promastigote and amastigote forms revealed that 3,832 genes are differentially expressed between promastigotes and intracellular amastigotes. A large proportion of genes that were downregulated during differentiation to amastigotes were associated with the function of the motile flagellum. In contrast, those genes that were upregulated included cell surface proteins, transporters, peptidases and many uncharacterized genes, including 293 of the 936 novel genes. Genome-wide distribution analysis of the differentially expressed genes revealed that the tetraploid chromosome 30 is highly enriched for genes that were upregulated in amastigotes, providing the first evidence of a link between this whole chromosome duplication event and adaptation to the vertebrate host in this group. Peptide evidence for 42 proteins encoded by novel transcripts supports the idea of an as yet uncharacterised set of small proteins in Leishmania spp. with possible implications for host-pathogen interactions. PMID:26452044

  11. Tracheal relaxation of five medicinal plants used in Mexico for the treatment of several diseases.

    PubMed

    Sánchez-Recillas, Amanda; Mantecón-Reyes, Paul; Castillo-España, Patricia; Villalobos-Molina, Rafael; Ibarra-Barajas, Maximiliano; Estrada-Soto, Samuel

    2014-03-01

    To assess the relaxant effect of several organic extracts obtained from Agastache mexicana (A. mexicana), Cochlospermum vitifolium (C. vitifolium), Cordia morelosana (C. morelosana), Lepechinia caulescens (L. caulescens) and Talauma mexicana (T. mexicana) used in Mexican traditional medicine for the treatment of several diseases. Extracts were obtained by maceration at room temperature using hexane, dichloromethane and methanol for each plant material. The organic extracts were evaluated ex vivo to determine their relaxant activity on the contractions induced by carbachol (cholinergic receptor agonist, 1 μ mol/L) in isolated rat tracheal rings. A total of 15 extracts were evaluated (three for each species). All test samples showed significant relaxant effect, in a concentration-dependent manner, on the contractions induced by 1 μ mol/L carbachol, with exception of extracts from C. morelosana. Active extracts were less potent than theophylline [phosphodiesterase inhibitor, EC50: (28.79±0.82) μg/mL] that was used as positive control. Concentration-response curves revealed that the extracts with more significant effects were dichloromethanic extracts of T. mexicana [Emax: (103.03±3.32)% and EC50: (159.39±3.72) μg/mL) and C. vitifolium [Emax: (106.58±2.42)% and EC50: (219.54±7.61) μg/mL]. Finally, hexanic and dichloromethanic extracts from A. mexicana were fully effective but less potent than T. mexicana and C. vitifolium. Less polar extracts obtained from A. mexicana, T. mexicana and C. vitifolium exhibited greater relaxant effect on tracheal rat rings, which allows us to suggest them as sources for the isolation of bioactive molecules with potential therapeutic value in the treatment of asthma. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  12. In vitro assessment of Argemone mexicana, Taraxacum officinale, Ruta chalepensis and Tagetes filifolia against Haemonchus contortus nematode eggs and infective (L3) larvae.

    PubMed

    Jasso Díaz, Gabriela; Hernández, Glafiro Torres; Zamilpa, Alejandro; Becerril Pérez, Carlos Miguel; Ramírez Bribiesca, J Efrén; Hernández Mendo, Omar; Sánchez Arroyo, Hussein; González Cortazar, Manasés; Mendoza de Gives, Pedro

    2017-08-01

    Argemone mexicana, Taraxacum officinale, Ruta chalepensis and Tagetes filifolia are plants with deworming potential. The purpose of this study was to evaluate methanolic extracts of aerial parts of these plants against Haemonchus contortus eggs and infective larvae (L3) and identify compounds responsible for the anthelmintic activity. In vitro probes were performed to identify the anthelmintic activity of plant extracts: egg hatching inhibition (EHI) and larvae mortality. Open column Chromatography was used to bio-guided fractionation of the extract, which shows the best anthelmintic effect. The lethal concentration to inhibit 50% of H. contortus egg hatching or larvae mortality (LC 50 ) was calculated using a Probit analysis. Bio-guided procedure led to the recognition of an active fraction (TF11) mainly composed by 1) quercetagitrin, 2) methyl chlorogenate and chlorogenic acid. Quercetagitrin (1) and methyl chlorogenate (2) did not show an important EHI activity (3-14%) (p < 0.05); however, chlorogenic acid (3) showed 100% of EHI (LC 50 248 μg/mL) (p < 0.05). Chlorogenic acid is responsible of the ovicidal activity and it seems that, this compound is reported for the first time with anthelmintic activity against a parasite of importance in sheep industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Quantity over quality: light intensity, but not red/far-red ratio, affects extrafloral nectar production in Senna mexicana var. chapmanii.

    PubMed

    Jones, Ian M; Koptur, Suzanne

    2015-09-01

    Extrafloral nectar (EFN) mediates food-for-protection mutualisms between plants and insects and provides plants with a form of indirect defense against herbivory. Understanding sources of variation in EFN production is important because such variations affect the number and identity of insect visitors and the effectiveness of plant defense. Light represents a potentially crucial tool for regulating resource allocation to defense, as it not only contributes energy but may help plants to anticipate future conditions. Low red/far-red (R/FR) light ratios can act as a signal of the proximity of competing plants. Exposure to such light ratios has been shown to promote competitive behaviors that coincide with reduced resource allocation to direct chemical defenses. Little is known, however, about how such informational light signals might affect indirect defenses such as EFN, and the interactions that they mediate. Through controlled glasshouse experiments, we investigated the effects of light intensity, and R/FR light ratios, on EFN production in Senna mexicana var. chapmanii. Plants in light-limited conditions produced significantly less EFN, and leaf damage elicited increased EFN production regardless of light conditions. Ratios of R/FR light, however, did not appear to affect EFN production in either damaged or undamaged plants. Understanding the effects of light on indirect defenses is of particular importance for plants in the threatened pine rockland habitats of south Florida, where light conditions are changing in predictable ways following extensive fragmentation and subsequent mismanagement. Around 27% of species in these habitats produce EFN and may rely on insect communities for defense.

  14. Survival in an extreme habitat: the roles of behaviour and energy limitation

    NASA Astrophysics Data System (ADS)

    Plath, Martin; Tobler, Michael; Riesch, Rüdiger; García de León, Francisco J.; Giere, Olav; Schlupp, Ingo

    2007-12-01

    Extreme habitats challenge animals with highly adverse conditions, like extreme temperatures or toxic substances. In this paper, we report of a fish ( Poecilia mexicana) inhabiting a limestone cave in Mexico. Several springs inside the cave are rich in toxic H2S. We demonstrate that a behavioural adaptation, aquatic surface respiration (ASR), allows for the survival of P. mexicana in this extreme, sulphidic habitat. Without the possibility to perform ASR, the survival rate of P. mexicana was low even at comparatively low H2S concentrations. Furthermore, we show that food limitation affects the survival of P. mexicana pointing to energetically costly physiological adaptations to detoxify H2S.

  15. Genetic structure and divergence in populations of Lutzomyia cruciata, a phlebotomine sand fly (Diptera: Psychodidae) vector of Leishmania mexicana in southeastern Mexico.

    PubMed

    Pech-May, Angélica; Marina, Carlos F; Vázquez-Domínguez, Ella; Berzunza-Cruz, Miriam; Rebollar-Téllez, Eduardo A; Narváez-Zapata, José A; Moo-Llanes, David; Ibáñez-Bernal, Sergio; Ramsey, Janine M; Becker, Ingeborg

    2013-06-01

    The low dispersal capacity of sand flies could lead to population isolation due to geographic barriers, climate variation, or to population fragmentation associated with specific local habitats due to landscape modification. The phlebotomine sand fly Lutzomyia cruciata has a wide distribution throughout Mexico and is a vector of Leishmania mexicana in the southeast. The aim of this study was to evaluate the genetic diversity, structure, and divergence within and among populations of Lu. cruciata in the state of Chiapas, and to infer the intra-specific phylogeny using the 3' end of the mitochondrial cytochrome b gene. We analyzed 62 sequences from four Lu. cruciata populations and found 26 haplotypes, high genetic differentiation and restricted gene flow among populations (Fst=0.416, Nm=0.701, p<0.001). The highest diversity values were recorded in populations from Loma Bonita and Guadalupe Miramar. Three lineages (100% bootstrap and 7% overall divergence) were identified using a maximum likelihood phylogenetic analysis which showed high genetic divergence (17.2-22.7%). A minimum spanning haplotype network also supported separation into three lineages. Genetic structure and divergence within and among Lu. cruciata populations are hence affected by geographic heterogeneity and evolutionary background. Data obtained in the present study suggest that Lu. cruciata in the state of Chiapas consists of at least three lineages. Such findings may have implications for vector capacity and hence for vector control strategies. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Predator Avoidance in Extremophile Fish

    PubMed Central

    Bierbach, David; Schulte, Matthias; Herrmann, Nina; Zimmer, Claudia; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Riesch, Rüdiger; Plath, Martin

    2013-01-01

    Extreme habitats are often characterized by reduced predation pressures, thus representing refuges for the inhabiting species. The present study was designed to investigate predator avoidance of extremophile populations of Poecilia mexicana and P. sulphuraria that either live in hydrogen sulfide-rich (sulfidic) springs or cave habitats, both of which are known to have impoverished piscine predator regimes. Focal fishes that inhabited sulfidic springs showed slightly weaker avoidance reactions when presented with several naturally occurring predatory cichlids, but strongest differences to populations from non-sulfidic habitats were found in a decreased shoaling tendency with non-predatory swordtail (Xiphophorus hellerii) females. When comparing avoidance reactions between P. mexicana from a sulfidic cave (Cueva del Azufre) and the adjacent sulfidic surface creek (El Azufre), we found only slight differences in predator avoidance, but surface fish reacted much more strongly to the non-predatory cichlid Vieja bifasciata. Our third experiment was designed to disentangle learned from innate effects of predator recognition. We compared laboratory-reared (i.e., predator-naïve) and wild-caught (i.e., predator-experienced) individuals of P. mexicana from a non-sulfidic river and found no differences in their reaction towards the presented predators. Overall, our results indicate (1) that predator avoidance is still functional in extremophile Poecilia spp. and (2) that predator recognition and avoidance reactions have a strong genetic basis. PMID:25371337

  17. Predator avoidance in extremophile fish.

    PubMed

    Bierbach, David; Schulte, Matthias; Herrmann, Nina; Zimmer, Claudia; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Riesch, Rüdiger; Plath, Martin

    2013-02-06

    Extreme habitats are often characterized by reduced predation pressures, thus representing refuges for the inhabiting species. The present study was designed to investigate predator avoidance of extremophile populations of Poecilia mexicana and P. sulphuraria that either live in hydrogen sulfide-rich (sulfidic) springs or cave habitats, both of which are known to have impoverished piscine predator regimes. Focal fishes that inhabited sulfidic springs showed slightly weaker avoidance reactions when presented with several naturally occurring predatory cichlids, but strongest differences to populations from non-sulfidic habitats were found in a decreased shoaling tendency with non-predatory swordtail (Xiphophorus hellerii) females. When comparing avoidance reactions between P. mexicana from a sulfidic cave (Cueva del Azufre) and the adjacent sulfidic surface creek (El Azufre), we found only slight differences in predator avoidance, but surface fish reacted much more strongly to the non-predatory cichlid Vieja bifasciata. Our third experiment was designed to disentangle learned from innate effects of predator recognition. We compared laboratory-reared (i.e., predator-naïve) and wild-caught (i.e., predator-experienced) individuals of P. mexicana from a non-sulfidic river and found no differences in their reaction towards the presented predators. Overall, our results indicate (1) that predator avoidance is still functional in extremophile Poecilia spp. and (2) that predator recognition and avoidance reactions have a strong genetic basis.

  18. Local adaptation and pronounced genetic differentiation in an extremophile fish, Poecilia mexicana, inhabiting a Mexican cave with toxic hydrogen sulphide.

    PubMed

    Plath, M; Hauswaldt, J S; Moll, K; Tobler, M; García De León, F J; Schlupp, I; Tiedemann, R

    2007-03-01

    We investigated genetic differentiation and migration patterns in a small livebearing fish, Poecilia mexicana, inhabiting a sulfidic Mexican limestone cave (Cueva del Azufre). We examined fish from three different cave chambers, the sulfidic surface creek draining the cave (El Azufre) and a nearby surface creek without the toxic hydrogen sulphide (Arroyo Cristal). Using microsatellite analysis of 10 unlinked loci, we found pronounced genetic differentiation among the three major habitats: Arroyo Cristal, El Azufre and the cave. Genetic differentiation was also found within the cave between different pools. An estimation of first-generation migrants suggests that (i) migration is unidirectional, out of the cave, and (ii) migration among different cave chambers occurs to some extent. We investigated if the pattern of genetic differentiation is also reflected in a morphological trait, eye size. Relatively large eyes were found in surface habitats, small eyes in the anterior cave chambers, and the smallest eyes were detected in the innermost cave chamber (XIII). This pattern shows some congruence with a previously proposed morphocline in eye size. However, our data do not support the proposed mechanism for this morphocline, namely that it would be maintained by migration from both directions into the middle cave chambers. This would have led to an increased variance in eye size in the middle cave chambers, which we did not find. Restricted gene flow between the cave and the surface can be explained by local adaptations to extreme environmental conditions, namely H2S and absence of light. Within the cave system, habitat properties are patchy, and genetic differentiation between cave chambers despite migration could indicate local adaptation at an even smaller scale.

  19. The Genomic Signature of Crop-Wild Introgression in Maize

    PubMed Central

    Hufford, Matthew B.; Lubinksy, Pesach; Pyhäjärvi, Tanja; Devengenzo, Michael T.; Ellstrand, Norman C.; Ross-Ibarra, Jeffrey

    2013-01-01

    The evolutionary significance of hybridization and subsequent introgression has long been appreciated, but evaluation of the genome-wide effects of these phenomena has only recently become possible. Crop-wild study systems represent ideal opportunities to examine evolution through hybridization. For example, maize and the conspecific wild teosinte Zea mays ssp. mexicana (hereafter, mexicana) are known to hybridize in the fields of highland Mexico. Despite widespread evidence of gene flow, maize and mexicana maintain distinct morphologies and have done so in sympatry for thousands of years. Neither the genomic extent nor the evolutionary importance of introgression between these taxa is understood. In this study we assessed patterns of genome-wide introgression based on 39,029 single nucleotide polymorphisms genotyped in 189 individuals from nine sympatric maize-mexicana populations and reference allopatric populations. While portions of the maize and mexicana genomes appeared resistant to introgression (notably near known cross-incompatibility and domestication loci), we detected widespread evidence for introgression in both directions of gene flow. Through further characterization of these genomic regions and preliminary growth chamber experiments, we found evidence suggestive of the incorporation of adaptive mexicana alleles into maize during its expansion to the highlands of central Mexico. In contrast, very little evidence was found for adaptive introgression from maize to mexicana. The methods we have applied here can be replicated widely, and such analyses have the potential to greatly inform our understanding of evolution through introgressive hybridization. Crop species, due to their exceptional genomic resources and frequent histories of spread into sympatry with relatives, should be particularly influential in these studies. PMID:23671421

  20. Antileishmanial activity of a mixture of Tridax procumbens and Allium sativum in mice

    PubMed Central

    Gamboa-Leon, Rubi; Vera-Ku, Marina; Peraza-Sanchez, Sergio R.; Ku-Chulim, Carlos; Horta-Baas, Aurelio; Rosado-Vallado, Miguel

    2014-01-01

    We tested a mixture of Tridax procumbens, known for its direct action against Leishmania mexicana, and Allium sativum, known for its immunomodulatory effect, as an alternative to treat cutaneous leishmaniasis. Acute oral toxicity was tested with the Up-and-Down Procedure (UDP) using a group of healthy mice administered with either T. procumbens or A. sativum extracts and compared with a control group. Liver injury and other parameters of toxicity were determined in mice at day 14. The in vivo assay was performed with mice infected with L. mexicana promastigotes and treated with either a mixture of T. procumbens and A. sativum or each extract separately. The thickness of the mice’s footpads was measured weekly. After the 12-week period of infection, blood samples were obtained by cardiac puncture to determine the total IgG, IgG1 and IgG2a immunoglobulins by a noncommercial indirect ELISA. We showed that the mixture of T. procumbens and A. sativum extracts was better at controlling L. mexicana infection while not being toxic when tested in the acute oral toxicity assay in mice. An increase in the ratio of IgG2a/IgG1 indicated a tendency to raise a Th1-type immune response in mice treated with the mixture. The mixture of T. procumbens and A. sativum extracts is a promising natural treatment for cutaneous leishmaniasis and its healing effects make it a good candidate for a possible new phytomedicine. PMID:24717526

  1. Mg/Ca-temperature calibration for costate Bulimina species (B. costata, B. inflata, B. mexicana): A paleothermometer for hypoxic environments

    NASA Astrophysics Data System (ADS)

    Grunert, Patrick; Rosenthal, Yair; Jorissen, Frans; Holbourn, Ann; Zhou, Xiaoli; Piller, Werner E.

    2018-01-01

    Costate species of Bulimina are cosmopolitan, infaunal benthic foraminifers which are common in the fossil record since the Paleogene. In the present study, we evaluate the temperature dependency of Mg/Ca ratios in Bulimina inflata, B. mexicana and B. costata from an extensive set of core-top samples from the Atlantic, Pacific and Indian Oceans. The results show no significant offset in Mg/Ca values between costate morphospecies when present in the same sample. The apparent lack of significant inter-specific/inter-morphotype differences amongst the analyzed costate buliminids allows for the combined use of their data-sets for our core-top calibration. Over a bottom-water temperature (BWT) range of 3-13 °C, the Bulimina species show a sensitivity of ∼0.12 mmol/mol/°C which is comparable to that of epifaunal Cibicidoides species and higher than that of the shallow infaunal Uvigerina spp., the most commonly used taxon in Mg/Ca-based palaeotemperature reconstruction. The reliability and accuracy of the new Mg/Ca-temperature calibration is corroborated in the fossil record by a case study in the Timor Sea which demonstrates the presence of southern-sourced waters at intermediate depths for the past 26,000 years. Costate species of Bulimina might thus provide a valuable alternative for BWT reconstruction in mesotrophic to eutrophic settings where many of the commonly used (more oligotrophic) species are rare or absent, and be particularly useful in hypoxic settings such as permanent upwelling zones where costate buliminids often dominate foraminiferal assemblages. The evaluation further reveals a mean positive offset of ∼0.2 mmol/mol of the Atlantic data-set over the Indo-Pacific data-set which contributes to the scatter in our calibration. Although an explanation for this offset is not straightforward and further research is necessary, we hypothesize that different levels of export production and carbonate ion concentrations in pore waters are likely reasons.

  2. A new endemic species of Willowsia from Florida (USA) and descriptive notes on all New World Willowsia (Collembola: Entomobryidae).

    PubMed

    Katz, Aron D

    2017-11-20

    Four species of Willowsia have been reported from the Americas (W. buski, W. jacobsoni, W. mexicana, and W. nigromaculata), and to date, W. mexicana is the only member of the genus endemic to the New World. Here, Willowsia pyrrhopygia sp. nov. from Florida is described. Like W. mexicana, this new species has a native New World distribution and uninterrupted rib scale type, but can be separated by color pattern and chaetotaxy. Dorsal head chaetotaxy and other descriptive notes are provided to compliment to descriptions for W. buski, W. jacobsoni, W. mexicana, and W. nigromaculata. Comparative morphological analysis also reveals two unique character states among Entomobryinae-the outer maxillary lobe with two (not three) sublobal hairs and the absence of labial triangle seta r-shared only by endemic New World Willowsia and Americabrya, providing preliminary support for their independent evolution from a common New World ancestor.

  3. Antileishmanial activity of a mixture of Tridax procumbens and Allium sativum in mice.

    PubMed

    Gamboa-Leon, Rubi; Vera-Ku, Marina; Peraza-Sanchez, Sergio R; Ku-Chulim, Carlos; Horta-Baas, Aurelio; Rosado-Vallado, Miguel

    2014-01-01

    We tested a mixture of Tridax procumbens, known for its direct action against Leishmania mexicana, and Allium sativum, known for its immunomodulatory effect, as an alternative to treat cutaneous leishmaniasis. Acute oral toxicity was tested with the Up-and-Down Procedure (UDP) using a group of healthy mice administered with either T. procumbens or A. sativum extracts and compared with a control group. Liver injury and other parameters of toxicity were determined in mice at day 14. The in vivo assay was performed with mice infected with L. mexicana promastigotes and treated with either a mixture of T. procumbens and A. sativum or each extract separately. The thickness of the mice's footpads was measured weekly. After the 12-week period of infection, blood samples were obtained by cardiac puncture to determine the total IgG, IgG1 and IgG2a immunoglobulins by a noncommercial indirect ELISA. We showed that the mixture of T. procumbens and A. sativum extracts was better at controlling L. mexicana infection while not being toxic when tested in the acute oral toxicity assay in mice. An increase in the ratio of IgG2a/IgG1 indicated a tendency to raise a Th1-type immune response in mice treated with the mixture. The mixture of T. procumbens and A. sativum extracts is a promising natural treatment for cutaneous leishmaniasis and its healing effects make it a good candidate for a possible new phytomedicine. © R. Gamboa-Leon et al., published by EDP Sciences, 2014.

  4. Chemotherapy and Drug Targeting in the Treatment of Leishmaniasis

    DTIC Science & Technology

    1990-05-30

    extremely inhibitory. ED50 for growth of promastigotes of L. mexicana sp. was as low as 5nM and up to 1O0uM. Sinefungi a natural nucleoside isclated from...synthesis increases and polyamine levels rise when the growth rate is maximal. Growth apnears to be related to and dependent upon polyamine biosynthesis...the growth of Hemophilus parainfluenzae. Since that time, pol, imines have been shown to be stimulatory to (or essential for) the grc~th of various

  5. Trophic relationships of small nonnative fishes in a natural creek and several agricultural drains flowing into the Salton Sea, and their potential, effects on the endangered desert pupfish

    USGS Publications Warehouse

    Martin, Barbara A.; Saiki, Michael K.

    2009-01-01

    This study was conducted to characterize trophic relationships of small nonnative fishes and to determine if predation by these fishes contributes to the decline of desert pupfish (Cyprinodon macularius), an endangered cyprinodont on the verge of extinction. We sampled 403 hybrid Mozambique tilapias (Oreochromis mossambica by O. urolepis), 107 redbelly tilapias (Tilapia zillii), 32 longjaw mudsuckers (Gillkhthys mirabilis), 182 western mosquitofish (Gambusia affinis), 222 sailfin mollies (Poecilia latipinna), 63 shortfin mollies (Poecilia mexicana), and 235 porthole livebearers (Poecilurpsis gracilis) from a natural creek and four agricultural drains during September 1999- December 2001. Evidence of piscivory was in gastrointestinal contents of 14 hybrid Mozambique tilapias, 3 redbelly tilapias, 10 longjaw mudsuckers, 8 western mosquitofish, 2 sailfin mollies, and 8 porthole livebearers. Although digestion often was too advanced for identification of fishes consumed by nonnative fishes, remains of desert pupfish were in gastrointestinal contents of a longjaw mudsucker. Our findings, along with Field evidence from other studies that inverse relationships exist between abundances of desert pupfish and nonnative species, are consistent with the hypothesis that predation by nonnative species is contributing to decline of desert pupfish. We suspect that competitive interactions with nonnative fishes might also adversely affect abundance of desert pupfish.

  6. Biochemistry and Chemotherapy of Leishmaniasis and Malaria

    DTIC Science & Technology

    1995-12-01

    Allium cepa) and licorice ( Glycyrrhiza glabra). Growth of cells of Leishmania chagasi 13 and Leishmania mexicana 227 was monitored after 72 hr at 590...Leishmania chagasi. Protein Conc. Percent Range Inhibition IC25 IC50 Natural Product Solvent (4g/ml) Range (4g/ml) (0g/ml) Glycyrrhiza AQ 15-150 7.3...jig/ml) Range (jg/ml) (jIg/ml) Glycyrrhiza AQ 15-150 26.4-41.7 6* none glabra ETOH 0.26-268 No Inhibition none none (licorice) Hydrastis AQ 5-15 0.0

  7. The social nature of natural childbirth.

    PubMed

    Mansfield, Becky

    2008-03-01

    This paper aims to develop a better understanding of what proponents of natural childbirth mean by "natural." Using a biosocial approach to birth that posits that all birth is both social and natural, the paper investigates how proponents represent the relationship between nature and society. The study asks about what kinds of nature-society relationships are expressed in proponents' representations of natural childbirth. The study examines how natural childbirth is represented by proponents in popular non-fictional English language books written for pregnant women. Claims in these books are not taken as reality, but are analyzed as ideas about nature-society relations. The central finding is that these authors simultaneously emphasize the naturalness of birth and showcase three types of social practices that they describe as being integral to natural childbirth: (1) activity during birth, (2) preparation before birth, and (3) social support, both in an individual and in a broader socio-cultural sense. At least for these authors, it is these social practices that allow natural childbirth to be natural. These findings on the social nature of natural childbirth challenge current social science scholarship, in which natural childbirth is characterized as an essentializing and nostalgic attempt to return to nature.

  8. Biochemistry and Chemotherapy of Malaria and Leishmaniasis

    DTIC Science & Technology

    1993-12-06

    sativum), elephant garlic (Allium scorodoprasum), onion (Allium cepa), and licorice ( Glycyrrhiza glabra). Cells of Leish- mania mexicana 227 and... Glycyrrhiza glabra) inhibited the growth of the leishmanial parasites, but were not toxic to HeLa cells. All of the extracts showed varying inhibitory...root) and Glycyrrhiza glabra (licorice). 10 * Materials & Methods Cultures of Parasitic Protozoa: Promastigotes of Leishmania mexicana Walter Reed

  9. NAFTA: A Partial Solution Not a Savior to Mexico’s Economic Woes

    DTIC Science & Technology

    2011-10-28

    Mexico .” Economia Mexicana. 15 January 2004. http://www.economiamexicana.cide.edu/num_anteriores/XIV-2/LILIANA_MEZA.pdf (accessed: 28 October 2011... Mexico .” Economia Mexicana. 15 January 2004. http://www.economiamexicana.cide.edu/num_anteriores/XIV-2/LILIANA_MEZA.pdf (accessed: 28 October 2011...Trade Agreement, NAFTA, Mexico Economy, Trade Liberalization 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a

  10. The Annual Meeting of the American Society of Tropical Medicine and Hygiene (38th) Held in Honolulu, Hawaii on 10-14 December 1989

    DTIC Science & Technology

    1991-01-01

    FOR IgG ANTIBODIES TO LEISHMANIA MEXICANA MEXICANA. M.R. Garcia*, F. Andrade, R. Esquivel, E. Simmonds, S. Canto, and A.L. Cruz. University of Yucatan ...Baltimore, MD; Universidad Peruana Cayetano Heredia; and Instituto de Investigacin Nutricional .?? 4:15 437 CHICKENPOX IN THE U.S. ARMY: A DEVELOPING... Yucatan (Mexico) Tropical Diseases Research Unit. Reference Center for Leishmaniasis Control. A total of 223 sera from human beings were processed by

  11. Convergent life-history shifts: toxic environments result in big babies in two clades of poeciliids

    NASA Astrophysics Data System (ADS)

    Riesch, Rüdiger; Plath, Martin; García de León, Francisco J.; Schlupp, Ingo

    2010-02-01

    The majority of studies on ecological speciation in animals have investigated the divergence caused by biotic factors like divergent food sources or predatory regimes. Here, we examined a system where ecological speciation can clearly be ascribed to abiotic environmental gradients of naturally occurring toxic hydrogen sulfide (H2S). In southern Mexico, two genera of livebearing fishes (Poeciliidae: Poecilia and Gambusia) thrive in various watercourses with different concentrations of H2S. Previous studies have revealed pronounced genetic differentiation between different locally adapted populations in one species ( Poecilia mexicana), pointing towards incipient speciation. In the present study, we examined female reproductive life-history traits in two species pairs: Gambusia sexradiata (from a nonsulfidic and a sulfidic habitat) and Gambusia eurystoma (sulfide-endemic), as well as P. mexicana (nonsulfidic and sulfidic) and Poecilia sulphuraria (sulfide endemic). We found convergent divergence of life-history traits in response to sulfide; most prominently, extremophile poeciliids exhibit drastically increased offspring size coupled with reduced fecundity. Furthermore, within each genus, this trend increased with increasing sulfide concentrations and was most pronounced in the two endemic sulfur-adapted species. We discuss the adaptive significance of large offspring size in toxic environments and propose that divergent life-history evolution may promote further ecological divergence through isolation by adaptation.

  12. The Comparative Genomics and Phylogenomics of Leishmania amazonensis Parasite.

    PubMed

    Tschoeke, Diogo A; Nunes, Gisele L; Jardim, Rodrigo; Lima, Joana; Dumaresq, Aline Sr; Gomes, Monete R; de Mattos Pereira, Leandro; Loureiro, Daniel R; Stoco, Patricia H; de Matos Guedes, Herbert Leonel; de Miranda, Antonio Basilio; Ruiz, Jeronimo; Pitaluga, André; Silva, Floriano P; Probst, Christian M; Dickens, Nicholas J; Mottram, Jeremy C; Grisard, Edmundo C; Dávila, Alberto Mr

    2014-01-01

    Leishmaniasis is an infectious disease caused by Leishmania species. Leishmania amazonensis is a New World Leishmania species belonging to the Mexicana complex, which is able to cause all types of leishmaniasis infections. The L. amazonensis reference strain MHOM/BR/1973/M2269 was sequenced identifying 8,802 codifying sequences (CDS), most of them of hypothetical function. Comparative analysis using six Leishmania species showed a core set of 7,016 orthologs. L. amazonensis and Leishmania mexicana share the largest number of distinct orthologs, while Leishmania braziliensis presented the largest number of inparalogs. Additionally, phylogenomic analysis confirmed the taxonomic position for L. amazonensis within the "Mexicana complex", reinforcing understanding of the split of New and Old World Leishmania. Potential non-homologous isofunctional enzymes (NISE) were identified between L. amazonensis and Homo sapiens that could provide new drug targets for development.

  13. The Comparative Genomics and Phylogenomics of Leishmania amazonensis Parasite

    PubMed Central

    Tschoeke, Diogo A; Nunes, Gisele L; Jardim, Rodrigo; Lima, Joana; Dumaresq, Aline SR; Gomes, Monete R; de Mattos Pereira, Leandro; Loureiro, Daniel R; Stoco, Patricia H; de Matos Guedes, Herbert Leonel; de Miranda, Antonio Basilio; Ruiz, Jeronimo; Pitaluga, André; Silva, Floriano P; Probst, Christian M; Dickens, Nicholas J; Mottram, Jeremy C; Grisard, Edmundo C; Dávila, Alberto MR

    2014-01-01

    Leishmaniasis is an infectious disease caused by Leishmania species. Leishmania amazonensis is a New World Leishmania species belonging to the Mexicana complex, which is able to cause all types of leishmaniasis infections. The L. amazonensis reference strain MHOM/BR/1973/M2269 was sequenced identifying 8,802 codifying sequences (CDS), most of them of hypothetical function. Comparative analysis using six Leishmania species showed a core set of 7,016 orthologs. L. amazonensis and Leishmania mexicana share the largest number of distinct orthologs, while Leishmania braziliensis presented the largest number of inparalogs. Additionally, phylogenomic analysis confirmed the taxonomic position for L. amazonensis within the “Mexicana complex”, reinforcing understanding of the split of New and Old World Leishmania. Potential non-homologous isofunctional enzymes (NISE) were identified between L. amazonensis and Homo sapiens that could provide new drug targets for development. PMID:25336895

  14. Phenology, natural enemies, and efficacy of horticultural oil for control of Chionaspis heterophyllae (Homoptera: Diaspididae) on Christmas tree plantations.

    PubMed

    Fondren, Kirsten M; McCullough, Deborah G

    2005-10-01

    Pine needle scale, Chionaspis pinifoliae (Fitch), and Chionaspis heterophyllae Cooley are important pests of Scots pine, Pinus sylvestris L., and other conifers in much of North America. On Christmas tree plantations, these insects are typically controlled by spraying broad-spectrum insecticides when the vulnerable immature stages are present. However, effective control of bivoltine populations can be difficult to achieve due to asynchronous hatch and development of the second generation. Our objectives were to 1) determine the phenology of the second generation of C. heterophyllae in Michigan; 2) characterize the natural enemy complex; and 3) assess the effectiveness of horticultural oil for control of C. heterophyllae on P. sylvestris Christmas tree plantations. We monitored scale populations in three counties in lower Michigan for 3 yr. Scale phenology was consistently associated with cumulative degree-days base 10 degrees C (DD(10 degrees C)). Second-generation egg hatch began at approximately 1230-1300 DD(10 degrees C), and continued for approximately 3 wk. The peak of the second instar coincided with 1500-1600 DD(10 degrees C). Common predators included the coccinellids Chilocorus stigma (Say) and Microweisia misella (LeConte). On average, 70% of the C. heterophyllae population in unsprayed fields was killed by predators in 1999. Two endoparasitic wasps, Encarsia bella Gahan and Marietta mexicana Howard (Hymenoptera: Aphelinidae), also were recovered. In 2000 and 2001, we applied a highly refined horticultural spray oil with a backpack mist blower at 1500-1600 DD(10 degrees). Scale mortality on trees treated with oil ranged from 66 to 80% and was similar to control achieved using conventional insecticides in both years.

  15. Aporphine alkaloids from Guatteria spp. with leishmanicidal activity.

    PubMed

    Montenegro, Hector; Gutiérrez, Marcelino; Romero, Luz I; Ortega-Barría, Eduardo; Capson, Todd L; Rios, Luis Cubilla

    2003-07-01

    Fractionation of Guatteria amplifolia yielded the alkaloids xylopine (1), nornuciferine (4), lysicamine (6), and laudanosine (5). Fractionation of Guatteria dumetorum yielded the alkaloids cryptodorine (2) and nornantenine (3). Compounds 1-4 demonstrated significant activity against Leishmania mexicana and L. panamensis. Xylopine (1) was among the most active compounds (LD 50 = 3 microM) and showed a 37-fold higher toxicity towards L. mexicana than macrophages, the regular host cells of Leishmania spp.

  16. Molecular Diversity between Salivary Proteins from New World and Old World Sand Flies with Emphasis on Bichromomyia olmeca, the Sand Fly Vector of Leishmania mexicana in Mesoamerica

    PubMed Central

    Townsend, Shannon; Pasos-Pinto, Silvia; Sanchez, Laura; Rasouli, Manoochehr; B. Guimaraes-Costa, Anderson; Aslan, Hamide; Francischetti, Ivo M. B.; Oliveira, Fabiano; Becker, Ingeborg; Kamhawi, Shaden; Ribeiro, Jose M. C.; Jochim, Ryan C.; Valenzuela, Jesus G.

    2016-01-01

    Background Sand fly saliva has been shown to have proteins with potent biological activities, salivary proteins that can be used as biomarkers of vector exposure, and salivary proteins that are candidate vaccines against different forms of leishmaniasis. Sand fly salivary gland transcriptomic approach has contributed significantly to the identification and characterization of many of these salivary proteins from important Leishmania vectors; however, sand fly vectors in some regions of the world are still neglected, as Bichromomyia olmeca (formerly known as Lutzomyia olmeca olmeca), a proven vector of Leishmania mexicana in Mexico and Central America. Despite the importance of this vector in transmitting Leishmania parasite in Mesoamerica there is no information on the repertoire of B. olmeca salivary proteins and their relationship to salivary proteins from other sand fly species. Methods and Findings A cDNA library of the salivary glands of wild-caught B. olmeca was constructed, sequenced, and analyzed. We identified transcripts encoding for novel salivary proteins from this sand fly species and performed a comparative analysis between B. olmeca salivary proteins and those from other sand fly species. With this new information we present an updated catalog of the salivary proteins specific to New World sand flies and salivary proteins common to all sand fly species. We also report in this work the anti-Factor Xa activity of Lofaxin, a salivary anticoagulant protein present in this sand fly species. Conclusions This study provides information on the first transcriptome of a sand fly from Mesoamerica and adds information to the limited repertoire of salivary transcriptomes from the Americas. This comparative analysis also shows a fast degree of evolution in salivary proteins from New World sand flies as compared with Old World sand flies. PMID:27409591

  17. Genetic evidence of enzootic leishmaniasis in a stray canine and Texas mouse from sites in west and central Texas

    PubMed Central

    Kipp, Evan J; Mariscal, Jacqueline; Armijos, Rodrigo X; Weigel, Margaret; Waldrup, Kenneth

    2016-01-01

    We detected Leishmania mexicana in skin biopsies taken from a stray canine (Canis familiaris) and Texas mouse (Peromyscus attwateri) at two ecologically disparate sites in west and central Texas using polymerase chain reaction (PCR). A single PCR-positive dog was identified from a sample of 96 stray canines and was collected in a peri-urban area in El Paso County, Texas. The PCR-positive P. attwateri was trapped at a wildlife reserve in Mason County, Texas, from a convenience sample of 20 sylvatic mammals of different species. To our knowledge, this represents the first description of L. mexicana in west Texas and extends the known geographic range of the parasite to an area that includes the arid Chihuahuan Desert. Our finding of L. mexicana in P. attwateri represents a new host record and is the first description of the parasite in a wild peromyscid rodent in the United States. PMID:27759765

  18. The Nature of Natural Hazards Communication (Invited)

    NASA Astrophysics Data System (ADS)

    Kontar, Y. Y.

    2013-12-01

    Some of the many issues of interest to natural hazards professionals include the analysis of proactive approaches to the governance of risk from natural hazards and approaches to broaden the scope of public policies related to the management of risks from natural hazards, as well as including emergency and environmental management, community development and spatial planning related to natural hazards. During the talk we will present results of scientific review, analysis and synthesis, which emphasize same new trends in communication of the natural hazards theories and practices within an up-to-the-minute context of new environmental and climate change issues, new technologies, and a new focus on resiliency. The presentation is divided into five sections that focus on natural hazards communication in terms of education, risk management, public discourse, engaging the public, theoretical perspectives, and new media. It includes results of case studies and best practices. It delves into natural hazards communication theories, including diffusion, argumentation, and constructivism, to name a few. The presentation will provide information about: (1) A manual of natural hazards communication for scientists, policymakers, and media; (2) An up-to-the-minute context of environmental hazards, new technologies & political landscape; (3) A work by natural hazards scientists for geoscientists working with social scientists and communication principles; (4) A work underpinned by key natural hazards communication theories and interspersed with pragmatic solutions; (5) A work that crosses traditional natural hazards boundaries: international, interdisciplinary, theoretical/applied. We will further explore how spatial planning can contribute to risk governance by influencing the occupation of natural hazard-prone areas, and review the central role of emergency management in risk policy. The goal of this presentation is to contribute to the augmentation of the conceptual framework

  19. Predator-induced changes of female mating preferences: innate and experiential effects

    PubMed Central

    2011-01-01

    Background In many species males face a higher predation risk than females because males display elaborate traits that evolved under sexual selection, which may attract not only females but also predators. Females are, therefore, predicted to avoid such conspicuous males under predation risk. The present study was designed to investigate predator-induced changes of female mating preferences in Atlantic mollies (Poecilia mexicana). Males of this species show a pronounced polymorphism in body size and coloration, and females prefer large, colorful males in the absence of predators. Results In dichotomous choice tests predator-naïve (lab-reared) females altered their initial preference for larger males in the presence of the cichlid Cichlasoma salvini, a natural predator of P. mexicana, and preferred small males instead. This effect was considerably weaker when females were confronted visually with the non-piscivorous cichlid Vieja bifasciata or the introduced non-piscivorous Nile tilapia (Oreochromis niloticus). In contrast, predator experienced (wild-caught) females did not respond to the same extent to the presence of a predator, most likely due to a learned ability to evaluate their predators' motivation to prey. Conclusions Our study highlights that (a) predatory fish can have a profound influence on the expression of mating preferences of their prey (thus potentially affecting the strength of sexual selection), and females may alter their mate choice behavior strategically to reduce their own exposure to predators. (b) Prey species can evolve visual predator recognition mechanisms and alter their mate choice only when a natural predator is present. (c) Finally, experiential effects can play an important role, and prey species may learn to evaluate the motivational state of their predators. PMID:21726456

  20. Antiprotozoal activity of Neurolaena lobata.

    PubMed

    Berger, I; Passreiter, C M; Cáceres, A; Kubelka, W

    2001-06-01

    Extracts, fractions and sesquiterpene lactones from Neurolaena lobata (L.) R. Br. (Asteraceae), a traditional medicinal plant from Guatemala, were tested in vitro against Leishmania spp. promastigotes, Trypanosoma cruzi trypomastigotes and epimastigotes and Trichomonas vaginalis trophozoites. The ethanol extract inhibited the parasite growth of L. mexicana, T. cruzi and T. vaginalis significantly. The pure germacranolides 1 and a mixture of 2 and 3, isolated from the ethonal extract, were highly active against L. mexicana and T. cruzi. Copyright 2001 John Wiley & Sons, Ltd.

  1. Natural Colorants: Food Colorants from Natural Sources.

    PubMed

    Sigurdson, Gregory T; Tang, Peipei; Giusti, M Mónica

    2017-02-28

    The color of food is often associated with the flavor, safety, and nutritional value of the product. Synthetic food colorants have been used because of their high stability and low cost. However, consumer perception and demand have driven the replacement of synthetic colorants with naturally derived alternatives. Natural pigment applications can be limited by lower stability, weaker tinctorial strength, interactions with food ingredients, and inability to match desired hues. Therefore, no single naturally derived colorant can serve as a universal alternative for a specified synthetic colorant in all applications. This review summarizes major environmental and biological sources for natural colorants as well as nature-identical counterparts. Chemical characteristics of prevalent pigments, including anthocyanins, carotenoids, betalains, and chlorophylls, are described. The possible applications and hues (warm, cool, and achromatic) of currently used natural pigments, such as anthocyanins as red and blue colorants, and possible future alternatives, such as purple violacein and red pyranoanthocyanins, are also discussed.

  2. Natural Childbirth

    MedlinePlus

    ... Safe Videos for Educators Search English Español Natural Childbirth KidsHealth / For Parents / Natural Childbirth What's in this ... the pain, extremely empowering and rewarding. About Natural Childbirth Natural childbirth is a "low-tech" way of ...

  3. In vitro activity of new N-benzyl-1H-benzimidazol-2-amine derivatives against cutaneous, mucocutaneous and visceral Leishmania species.

    PubMed

    Nieto-Meneses, Rocío; Castillo, Rafael; Hernández-Campos, Alicia; Maldonado-Rangel, Armando; Matius-Ruiz, Jeferson B; Trejo-Soto, Pedro Josué; Nogueda-Torres, Benjamín; Dea-Ayuela, Ma Auxiliadora; Bolás-Fernández, Francisco; Méndez-Cuesta, Carlos; Yépez-Mulia, Lilián

    2018-01-01

    The identification of specific therapeutic targets and the development of new drugs against leishmaniasis are urgently needed, since chemotherapy currently available for its treatment has several problems including many adverse side effects. In an effort to develop new antileishmanial drugs, in the present study a series of 28 N-benzyl-1H-benzimidazol-2-amine derivatives was synthesized and evaluated in vitro against Leishmania mexicana promastigotes. Compounds 7 and 8 with the highest antileishmanial activity (micromolar) and lower cytotoxicity than miltefosine and amphotericin B were selected to evaluate their activity against L. braziliensis 9and L. donovani, species causative of mucocutaneous and visceral leishmaniasis, respectively. Compound 7 showed significantly higher activity against L. braziliensis promastigotes than compound 8 and slightly lower than miltefosine. Compounds 7 and 8 had IC 50 values in the micromolar range against the amastigote of L. mexicana and L. braziliensis. However, both compounds did not show better activity against L. donovani than miltefosine. Compound 8 showed the highest SI against both parasite stages of L. mexicana. In addition, compound 8 inhibited 68.27% the activity of recombinant L. mexicana arginase (LmARG), a therapeutic target for the treatment of leishmaniasis. Docking studies were also performed in order to establish the possible mechanism of action by which this compound exerts its inhibitory effect. Compound 8 shows promising potential for the development of more potent antileishmanial benzimidazole derivatives. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Trypanosomatidae produce acetate via a mitochondrial acetate:succinate CoA transferase

    PubMed Central

    Van Hellemond, Jaap J.; Opperdoes, Fred R.; Tielens, Aloysius G. M.

    1998-01-01

    Hydrogenosome-containing anaerobic protists, such as the trichomonads, produce large amounts of acetate by an acetate:succinate CoA transferase (ASCT)/succinyl CoA synthetase cycle. The notion that mitochondria and hydrogenosomes may have originated from the same α-proteobacterial endosymbiont has led us to look for the presence of a similar metabolic pathway in trypanosomatids because these are the earliest-branching mitochondriate eukaryotes and because they also are known to produce acetate. The mechanism of acetate production in these organisms, however, has remained unknown. Four different members of the trypanosomatid family: promastigotes of Leishmania mexicana mexicana, L. infantum and Phytomonas sp., and procyclics of Trypanosoma brucei were analyzed as well as the parasitic helminth Fasciola hepatica. They all use a mitochondrial ASCT for the production of acetate from acetyl CoA. The succinyl CoA that is produced during acetate formation by ASCT is recycled presumably to succinate by a mitochondrial succinyl CoA synthetase, concomitantly producing ATP from ADP. The ASCT of L. mexicana mexicana promastigotes was further characterized after partial purification of the enzyme. It has a high affinity for acetyl CoA (Km 0.26 mM) and a low affinity for succinate (Km 6.9 mM), which shows that significant acetate production can occur only when high mitochondrial succinate concentrations prevail. This study identifies a metabolic pathway common to mitochondria and hydrogenosomes, which strongly supports a common origin for these two organelles. PMID:9501211

  5. Mother natural: Motivations and associations for consuming natural foods.

    PubMed

    Moscato, Emily M; Machin, Jane E

    2018-02-01

    Natural is perceived as innately positive and is a widely sought-after attribute in food products. The natural food industry continues to grow in response to rising consumer demand. This qualitative study explored mothers' motivations for purchasing and consuming natural food products for themselves and their families. Mothers are an important population because of their disproportionate influence on household food consumption. We employed participant photography and a series of three weekly focus groups to derive a rich understanding of the activities surrounding and motivations behind seeking natural in everyday buying decisions. Five major themes were identified. First, natural nurtures well-being: physical, psychological, social, and emotional health. Second, natural behaves "supernaturally," allowing positive attributes to be transmitted from the source to the recipient. Third, natural is associated with authenticity, providing a sense of trust, transparency, and control. Fourth, consuming natural reinforces the socially constructed idea of a good mother. Lastly, the preference for natural does not always translate into purchase; mothers face compromises because of conflicting priorities and resources. Understanding mothers' multiple motivations provides deeper insight into the attraction for natural products. The findings have application in positioning interventions for more nutritional eating and revising regulations on the food label natural. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Cloning, expression, purification and characterization of triosephosphate isomerase from Trypanosoma cruzi.

    PubMed

    Ostoa-Saloma, P; Garza-Ramos, G; Ramírez, J; Becker, I; Berzunza, M; Landa, A; Gómez-Puyou, A; Tuena de Gómez-Puyou, M; Pérez-Montfort, R

    1997-03-15

    The gene that encodes for triosephosphate isomerase from Trypanosoma cruzi was cloned and sequenced. In T. cruzi, there is only one gene for triosephosphate isomerase. The enzyme has an identity of 72% and 68% with triosephosphate isomerase from Trypanosoma brucei and Leishmania mexicana, respectively. The active site residues are conserved: out of the 32 residues that conform the interface of dimeric triosephosphate isomerase from T. brucei, 29 are conserved in the T. cruzi enzyme. The enzyme was expressed in Escherichia coli and purified to homogeneity. Data from electrophoretic analysis under denaturing techniques and filtration techniques showed that triosephosphate isomerase from T. cruzi is a homodimer. Some of its structural and kinetic features were determined and compared to those of the purified enzymes from T. brucei and L. mexicana. Its circular dichroism spectrum was almost identical to that of triosephosphate isomerase from T. brucei. Its kinetic properties and pH optima were similar to those of T. brucei and L. mexicana, although the latter exhibited a higher Vmax with glyceraldehyde 3-phosphate as substrate. The sensitivity of the three enzymes to the sulfhydryl reagent methylmethane thiosulfonate (MeSO2-SMe) was determined; the sensitivity of the T. cruzi enzyme was about 40 times and 200 times higher than that of the enzymes from T. brucei and L. mexicana, respectively. Triosephosphate isomerase from T. cruzi and L. mexicana have the three cysteine residues that exist in the T. brucei enzyme (positions 14, 39, 126, using the numbering of the T. brucei enzyme); however, they also have an additional residue (position 117). These data suggest that regardless of the high identity of the three trypanosomatid enzymes, there are structural differences in the disposition of their cysteine residues that account for their different sensitivity to the sulfhydryl reagent. The disposition of the cysteine in triosephosphate isomerase from T. cruzi appears to

  7. Natural and engineered biosynthesis of fluorinated natural products.

    PubMed

    Walker, Mark C; Chang, Michelle C Y

    2014-09-21

    Both natural products and synthetic organofluorines play important roles in the discovery and design of pharmaceuticals. The combination of these two classes of molecules has the potential to be useful in the ongoing search for new bioactive compounds but our ability to produce site-selectively fluorinated natural products remains limited by challenges in compatibility between their high structural complexity and current methods for fluorination. Living systems provide an alternative route to chemical fluorination and could enable the production of organofluorine natural products through synthetic biology approaches. While the identification of biogenic organofluorines has been limited, the study of the native organisms and enzymes that utilize these compounds can help to guide efforts to engineer the incorporation of this unusual element into complex pharmacologically active natural products. This review covers recent advances in understanding both natural and engineered production of organofluorine natural products.

  8. The nature and ethics of natural experiments.

    PubMed

    Dawson, Angus; Sim, Julius

    2015-10-01

    Natural experiments are an important methodology often used to answer research questions that would, otherwise, be impossible to address, or employed because of ethical concerns about the use of randomisation to interventions that carry known risks. The UK Medical Research Council (MRC) recently produced an extremely useful document discussing the nature and significance of natural experiments within medical and public health research. In this paper, however, we suggest that the MRC document's definition of the term 'natural experiment' is insufficiently precise. In response, we offer a taxonomy of different types of natural experiments and related methods, and explore the ethical implications of these different types. We argue that while the ethical issues that may arise within natural experiments in relation to risks of harm or informed consent may differ from those within the randomised controlled trial, they are not thereby less pressing. The implications of the argument are explored and recommendations made for those involved in research governance. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  9. Monocyte-Derived Signals Activate Human Natural Killer Cells in Response to Leishmania Parasites

    PubMed Central

    Messlinger, Helena; Sebald, Heidi; Heger, Lukas; Dudziak, Diana; Bogdan, Christian; Schleicher, Ulrike

    2018-01-01

    Activated natural killer (NK) cells release interferon (IFN)-γ, which is crucial for the control of intracellular pathogens such as Leishmania. In contrast to experimental murine leishmaniasis, the human NK cell response to Leishmania is still poorly characterized. Here, we investigated the interaction of human blood NK cells with promastigotes of different Leishmania species (Leishmania major, Leishmania mexicana, Leishmania infantum, and Leishmania donovani). When peripheral blood mononuclear cells or purified NK cells and monocytes (all derived from healthy blood donors from Germany without a history of leishmaniasis) were exposed to promastigotes, NK cells showed increased surface expression of the activation marker CD69. The extent of this effect varied depending on the Leishmania species; differences between dermotropic and viscerotropic L. infantum strains were not observed. Upregulation of CD69 required direct contact between monocytes and Leishmania and was partly inhibitable by anti-interleukin (IL)-18. Unexpectedly, IL-18 was undetectable in most of the supernatants (SNs) of monocyte/parasite cocultures. Confocal fluorescence microscopy of non-permeabilized cells revealed that Leishmania-infected monocytes trans-presented IL-18 to NK cells. Native, but not heat-treated SNs of monocyte/Leishmania cocultures also induced CD69 on NK cells, indicating the involvement of a soluble heat-labile factor other than IL-18. A role for the NK cell-activating cytokines IL-1β, IL-2, IL-12, IL-15, IL-21, and IFN-α/β was excluded. The increase of CD69 was not paralleled by NK cell IFN-γ production or enhanced cytotoxicity. However, prior exposure of NK cells to Leishmania parasites synergistically increased their IFN-γ release in response to IL-12, which was dependent on endogenous IL-18. CD1c+ dendritic cells were identified as possible source of Leishmania-induced IL-12. Finally, we observed that direct contact between Leishmania and NK cells reduced the

  10. Naturally Speaking: The Naturalness Criterion and Physics at the LHC

    NASA Astrophysics Data System (ADS)

    Giudice, Gian Francesco

    The following sections are included: * Naturalness in Scientific Thought * Drowning by Numbers * A Quantum Complication * The Naturalness Criterion as a Principle * An Account of Events * The Paths Chosen by Nature * Measuring Naturalness * Anthropic Reasoning * Naturalness versus Criticality * Conclusions * References

  11. [Development of the Feelings toward Nature Scale and relationship between feelings toward nature and proximity to nature].

    PubMed

    Shibata, Seiji

    2016-04-01

    In the field of environmental psychology, there is rapidly growing interest in the concept of connectivity with nature, describing an individual's sense of being connected with nature. The author developed a new scale for assessing feelings toward nature, including connectedness. Confirmatory factor analysis indicated a five-factor model consisting of restorativeness, oneness, mystery, care, and aversion. Then, the relationships among availability of nature in respondents' neighborhood, age, and each subscale score of the Feelings toward Nature Scale, were analyzed using structural equation modeling. The availability of nature in neighborhoods was assessed using a geographic information system and respondents' subjective evaluations. Results indicate that overall connectedness to nature is weaker as availability of nature decreases, as assessed by subjective evaluation. Results also suggest that aversion toward nature in younger people is relatively stronger than in older generations.

  12. In vitro antileishmanial and cytotoxicity activities of essential oils from Haplophyllum tuberculatum A. Juss leaves, stems and aerial parts.

    PubMed

    Hamdi, Assia; Bero, Joanne; Beaufay, Claire; Flamini, Guido; Marzouk, Zohra; Vander Heyden, Yvan; Quetin-Leclercq, Joelle

    2018-02-14

    Plants used for traditional medicine produce diverse and complex secondary metabolites exhibiting various medicinal properties. The medicinal plant Haplophyllum tuberculatum is used by native people against malaria and parasitic infections. In this study and in order to contribute for the search of new natural drugs for leishmaniasis, the essential oils of H. tuberculatum leaves, stems and aerial parts (leaves+stems) collected in two different periods, 2013 and 2015, and their components by GC/FID and GC/MS analyses were investigated. Those collected in 2013 were also re-analyzed two years later. The extracted oils were screened in vitro for anti-leishmanial activity on Leishmania mexicana mexicana (L.m.m.) promastigotes and cytotoxicity on the Chinese Hamster Ovary (CHO) cell line. Limonene (1.5 - 8%), its isomers (R- (+)-limonene and S-(-)-limonene), linalool and octanol were also tested. Results showed that the chemical composition varied according to the year of collection. Though major compounds remain almost the same, qualitative and quantitative variations in the composition of the EOs can be observed between the two years of collection, with some minor compounds identified only in one type of samples. Variation in the composition were also observed in the re-analyzed volatile oils, showing stability concerns. The essential oils and R-(+)-limonene showed moderate anti-leishmanial activity. Their IC 50 range from 6.48 to 50.28 μg/ml. Cytotoxicity assays for theses volatile extracts, R- (+)-limonene and S- (-)-limonene on CHO cells showed relatively potent cytotoxicity with a selectivity index <10. Their CC 50 range from 27.79 to 82.56 μg/ml. The findings of the present study demonstrated that H. tuberculatum might not be considered as a natural source for production of new anti-leishmanial agents without further analyzing its eventual in vivo toxicity as well as that of major pure compounds.

  13. Which naturalism for bioethics? A defense of moderate (pragmatic) naturalism.

    PubMed

    Racine, Eric

    2008-02-01

    There is a growing interest in various forms of naturalism in bioethics, but there is a clear need for further clarification. In an effort to address this situation, I present three epistemological stances: anti-naturalism, strong naturalism, and moderate pragmatic naturalism. I argue that the dominant paradigm within philosophical ethics has been a form of anti-naturalism mainly supported by a strong 'is' and 'ought' distinction. This fundamental epistemological commitment has contributed to the estrangement of academic philosophical ethics from major social problems and explains partially why, in the early 1980s, 'medicine saved the life of ethics'. Rejection of anti-naturalism, however, is often associated with strong forms of naturalism that commit the naturalistic fallacy and threaten to reduce the normative dimensions of ethics to biological imperatives. This move is rightly dismissed as a pitfall since ethics is, in part, a struggle against the course of nature. Rejection of naturalism has drawbacks, however, such as deterring bioethicists from acknowledging the implicit naturalistic epistemological commitments of bioethics. I argue that a moderate pragmatic form of naturalism represents an epistemological position that best embraces the tension of anti-naturalism and strong naturalism: bioethics is neither disconnected from empirical knowledge nor subjugated to it. The discussion is based upon historical writings in philosophy and bioethics.

  14. Bodies in nature: Associations between exposure to nature, connectedness to nature, and body image in U.S. adults.

    PubMed

    Swami, Viren; Barron, David; Weis, Laura; Furnham, Adrian

    2016-09-01

    Here, we sought to replicate previous work showing a relationship between connectedness to nature and body appreciation, and extend it by examining associations between exposure to natural environments and other body image-related variables. An online sample of 399 U.S. women and men (Mage=34.55 years) completed measures of body appreciation, connectedness to nature, nature exposure, appearance investment, sociocultural attitudes towards appearance, and self-esteem. Path analysis showed that nature exposure and connectedness to nature, respectively, were associated with body appreciation in women and men, both directly and indirectly via self-esteem. Connectedness to nature also mediated the link between nature exposure and body appreciation. In men, but not women, the link between connectedness to nature and body appreciation was also mediated by appearance investment and internalisation of a muscular ideal. These results may point to novel methods for promoting more positive body image in adults through engagement with nature. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Temporal naturalism

    NASA Astrophysics Data System (ADS)

    Smolin, Lee

    2015-11-01

    Two people may claim both to be naturalists, but have divergent conceptions of basic elements of the natural world which lead them to mean different things when they talk about laws of nature, or states, or the role of mathematics in physics. These disagreements do not much affect the ordinary practice of science which is about small subsystems of the universe, described or explained against a background, idealized to be fixed. But these issues become crucial when we consider including the whole universe within our system, for then there is no fixed background to reference observables to. I argue here that the key issue responsible for divergent versions of naturalism and divergent approaches to cosmology is the conception of time. One version, which I call temporal naturalism, holds that time, in the sense of the succession of present moments, is real, and that laws of nature evolve in that time. This is contrasted with timeless naturalism, which holds that laws are immutable and the present moment and its passage are illusions. I argue that temporal naturalism is empirically more adequate than the alternatives, because it offers testable explanations for puzzles its rivals cannot address, and is likely a better basis for solving major puzzles that presently face cosmology and physics. This essay also addresses the problem of qualia and experience within naturalism and argues that only temporal naturalism can make a place for qualia as intrinsic qualities of matter.

  16. Nature's Trust: A Paradigm for Natural Resources Stewardship

    NASA Astrophysics Data System (ADS)

    Wood, M. C.; Whitelaw, E.; Doppelt, B.; Burchell, A.

    2007-12-01

    Climate change uncertainty puts a premium on all remaining natural resources. Farmland, air, water, wetlands, wildlife, soils, mineral resources and forests must be protected to ensure that Americans - present citizens and future generations - have the fundamental survival resources they need in a future that holds many unknowns. Moreover, in light of the need to manage resources given climate and particle forcing, government must mitigate dangerous carbon loading of the atmosphere. Confronting climate change and protecting natural resources requires a clear sense of government obligation that is inherent to sovereignty, not a matter of political choice. Our government representatives can and must reframe government's discretion into a trustee obligation to protect Nature and ensure natural resource stewardship. Drawing upon enduring legal principles and court decisions, government can be characterized as a trustee of the natural resources essential to human survival. A trust is a fundamental type of ownership whereby one manages property for the benefit of another. Viewed as a trust, the environment consists of a portfolio of quantified natural assets that government manages. As beneficiaries, citizens hold a common property interest in defined, bounded assets that make up Nature's Trust. Such trust principles form the bedrock of statutory law. Trustees have a fiduciary obligation to protect trust assets and may not allow destruction of property they manage. This session will provide a policy frame for current scientific efforts to address climate change and natural resources loss. Under the Nature's Trust frame, U.S. government leaders and agencies at every level inherit a strict fiduciary obligation to protect our collective natural resources, including our water and the atmosphere, as assets in the trust. Their fiduciary standard of care consists of a proportionate responsibility, which ties directly to "Nature's Mandate" as defined by current climate

  17. The leishmanicidal effect of (3S)-16,17-didehydrofalcarinol, an oxylipin isolated from Tridax procumbens, is independent of NO production.

    PubMed

    Martín-Quintal, Zhelmy; del Rosario García-Miss, María; Mut-Martín, Mirza; Matus-Moo, Abril; Torres-Tapia, Luis W; Peraza-Sánchez, Sergio R

    2010-07-01

    The in vitro leishmanicidal effect of (3S)-16,17-didehydrofalcarinol (1) isolated from Tridax procumbens whole plant against Leishmania mexicana, the causative agent of cutaneous leishmaniasis (chiclero's ulcer) in the New World, was investigated. This oxylipin showed significant in vitro activity against promastigotes and intracellular amastigotes of L. mexicana. Its inhibitory effect on amastigotes was not due to activation of NO in recombinant gamma-interferon-stimulated macrophages, since the production of NO was decreased in presence of the oxylipin. This is the first report on the leishmanicidal activity against the intracellular stage (amastigote) of the oxylipin (3S)-16,17-didehydrofalcarinol.

  18. Natural Nanoparticles: A Particular Matter Inspired by Nature.

    PubMed

    Griffin, Sharoon; Masood, Muhammad Irfan; Nasim, Muhammad Jawad; Sarfraz, Muhammad; Ebokaiwe, Azubuike Peter; Schäfer, Karl-Herbert; Keck, Cornelia M; Jacob, Claus

    2017-12-29

    During the last couple of decades, the rapidly advancing field of nanotechnology has produced a wide palette of nanomaterials, most of which are considered as "synthetic" and, among the wider public, are often met with a certain suspicion. Despite the technological sophistication behind many of these materials, "nano" does not always equate with "artificial". Indeed, nature itself is an excellent nanotechnologist. It provides us with a range of fine particles, from inorganic ash, soot, sulfur and mineral particles found in the air or in wells, to sulfur and selenium nanoparticles produced by many bacteria and yeasts. These nanomaterials are entirely natural, and, not surprisingly, there is a growing interest in the development of natural nanoproducts, for instance in the emerging fields of phyto- and phyco-nanotechnology. This review will highlight some of the most recent-and sometimes unexpected-advances in this exciting and diverse field of research and development. Naturally occurring nanomaterials, artificially produced nanomaterials of natural products as well as naturally occurring or produced nanomaterials of natural products all show their own, particular chemical and physical properties, biological activities and promise for applications, especially in the fields of medicine, nutrition, cosmetics and agriculture. In the future, such natural nanoparticles will not only stimulate research and add a greener outlook to a traditionally high-tech field, they will also provide solutions-pardon-suspensions for a range of problems. Here, we may anticipate specific biogenic factories, valuable new materials based on waste, the effective removal of contaminants as part of nano-bioremediation, and the conversion of poorly soluble substances and materials to biologically available forms for practical uses.

  19. Natural Nanoparticles: A Particular Matter Inspired by Nature

    PubMed Central

    Griffin, Sharoon; Masood, Muhammad Irfan; Nasim, Muhammad Jawad; Sarfraz, Muhammad; Ebokaiwe, Azubuike Peter; Schäfer, Karl-Herbert; Keck, Cornelia M.; Jacob, Claus

    2017-01-01

    During the last couple of decades, the rapidly advancing field of nanotechnology has produced a wide palette of nanomaterials, most of which are considered as “synthetic” and, among the wider public, are often met with a certain suspicion. Despite the technological sophistication behind many of these materials, “nano” does not always equate with “artificial”. Indeed, nature itself is an excellent nanotechnologist. It provides us with a range of fine particles, from inorganic ash, soot, sulfur and mineral particles found in the air or in wells, to sulfur and selenium nanoparticles produced by many bacteria and yeasts. These nanomaterials are entirely natural, and, not surprisingly, there is a growing interest in the development of natural nanoproducts, for instance in the emerging fields of phyto- and phyco-nanotechnology. This review will highlight some of the most recent—and sometimes unexpected—advances in this exciting and diverse field of research and development. Naturally occurring nanomaterials, artificially produced nanomaterials of natural products as well as naturally occurring or produced nanomaterials of natural products all show their own, particular chemical and physical properties, biological activities and promise for applications, especially in the fields of medicine, nutrition, cosmetics and agriculture. In the future, such natural nanoparticles will not only stimulate research and add a greener outlook to a traditionally high-tech field, they will also provide solutions—pardon—suspensions for a range of problems. Here, we may anticipate specific biogenic factories, valuable new materials based on waste, the effective removal of contaminants as part of nano-bioremediation, and the conversion of poorly soluble substances and materials to biologically available forms for practical uses. PMID:29286304

  20. Nature's palette: the search for natural blue colorants.

    PubMed

    Newsome, Andrew G; Culver, Catherine A; van Breemen, Richard B

    2014-07-16

    The food and beverage industry is seeking to broaden the palette of naturally derived colorants. Although considerable effort has been devoted to the search for new blue colorants in fruits and vegetables, less attention has been directed toward blue compounds from other sources such as bacteria and fungi. The current work reviews known organic blue compounds from natural plant, animal, fungal, and microbial sources. The scarcity of blue-colored metabolites in the natural world relative to metabolites of other colors is discussed, and structural trends common among natural blue compounds are identified. These compounds are grouped into seven structural classes and evaluated for their potential as new color additives.

  1. Capturing Nature's Diversity

    PubMed Central

    Pascolutti, Mauro; Campitelli, Marc; Nguyen, Bao; Pham, Ngoc; Gorse, Alain-Dominique; Quinn, Ronald J.

    2015-01-01

    Natural products are universally recognized to contribute valuable chemical diversity to the design of molecular screening libraries. The analysis undertaken in this work, provides a foundation for the generation of fragment screening libraries that capture the diverse range of molecular recognition building blocks embedded within natural products. Physicochemical properties were used to select fragment-sized natural products from a database of known natural products (Dictionary of Natural Products). PCA analysis was used to illustrate the positioning of the fragment subset within the property space of the non-fragment sized natural products in the dataset. Structural diversity was analysed by three distinct methods: atom function analysis, using pharmacophore fingerprints, atom type analysis, using radial fingerprints, and scaffold analysis. Small pharmacophore triplets, representing the range of chemical features present in natural products that are capable of engaging in molecular interactions with small, contiguous areas of protein binding surfaces, were analysed. We demonstrate that fragment-sized natural products capture more than half of the small pharmacophore triplet diversity observed in non fragment-sized natural product datasets. Atom type analysis using radial fingerprints was represented by a self-organizing map. We examined the structural diversity of non-flat fragment-sized natural product scaffolds, rich in sp3 configured centres. From these results we demonstrate that 2-ring fragment-sized natural products effectively balance the opposing characteristics of minimal complexity and broad structural diversity when compared to the larger, more complex fragment-like natural products. These naturally-derived fragments could be used as the starting point for the generation of a highly diverse library with the scope for further medicinal chemistry elaboration due to their minimal structural complexity. This study highlights the possibility to capture a

  2. Egg load decreases mobility and increases predation risk in female black-horned tree crickets (Oecanthus nigricornis).

    PubMed

    Ercit, Kyla; Martinez-Novoa, Andrew; Gwynne, Darryl T

    2014-01-01

    Female-biased predation is an uncommon phenomenon in nature since males of many species take on riskier behaviours to gain more mates. Several species of sphecid wasps have been observed taking more female than male prey, and it is not fully understood why. The solitary sphecid Isodontia mexicana catches more adult female tree cricket (Oecanthus nigricornis) prey. Previous work has shown that, although female tree crickets are larger and thus likely to be more valuable as prey than males, body size alone cannot fully explain why wasps take more females. We tested the hypothesis that wasps catch adult female tree crickets more often because bearing eggs impedes a female's ability to escape predation. We compared female survivors to prey of I. mexicana, and found that females carrying more eggs were significantly more likely to be caught by wasps, regardless of their body size and jumping leg mass. We also conducted laboratory experiments where females' jumping responses to a simulated attack were measured and compared to her egg load and morphology. We found a significant negative relationship between egg load and jumping ability, and a positive relationship between body size and jumping ability. These findings support the hypothesis that ovarian eggs are a physical handicap that contributes to female-biased predation in this system. Predation on the most fecund females may have ecological-evolutionary consequences such as collapse of prey populations or selection for alternate life history strategies and behaviours.

  3. Why Is Nature Beneficial?: The Role of Connectedness to Nature

    ERIC Educational Resources Information Center

    Mayer, F. Stephan; Frants, Cynthia McPherson; Bruehlman-Senecal, Emma; Dolliver, Kyffin

    2009-01-01

    Three studies examine the effects of exposure to nature on positive affect and ability to reflect on a life problem. Participants spent 15 min walking in a natural setting (Studies 1, 2, & 3), an urban setting (Study 1), or watching videos of natural and urban settings (Studies 2 & 3). In all three studies, exposure to nature increased…

  4. Natural Gas Prices Forecast Comparison--AEO vs. Natural Gas Markets

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wong-Parodi, Gabrielle; Lekov, Alex; Dale, Larry

    This paper evaluates the accuracy of two methods to forecast natural gas prices: using the Energy Information Administration's ''Annual Energy Outlook'' forecasted price (AEO) and the ''Henry Hub'' compared to U.S. Wellhead futures price. A statistical analysis is performed to determine the relative accuracy of the two measures in the recent past. A statistical analysis suggests that the Henry Hub futures price provides a more accurate average forecast of natural gas prices than the AEO. For example, the Henry Hub futures price underestimated the natural gas price by 35 cents per thousand cubic feet (11.5 percent) between 1996 and 2003more » and the AEO underestimated by 71 cents per thousand cubic feet (23.4 percent). Upon closer inspection, a liner regression analysis reveals that two distinct time periods exist, the period between 1996 to 1999 and the period between 2000 to 2003. For the time period between 1996 to 1999, AEO showed a weak negative correlation (R-square = 0.19) between forecast price by actual U.S. Wellhead natural gas price versus the Henry Hub with a weak positive correlation (R-square = 0.20) between forecasted price and U.S. Wellhead natural gas price. During the time period between 2000 to 2003, AEO shows a moderate positive correlation (R-square = 0.37) between forecasted natural gas price and U.S. Wellhead natural gas price versus the Henry Hub that show a moderate positive correlation (R-square = 0.36) between forecast price and U.S. Wellhead natural gas price. These results suggest that agencies forecasting natural gas prices should consider incorporating the Henry Hub natural gas futures price into their forecasting models along with the AEO forecast. Our analysis is very preliminary and is based on a very small data set. Naturally the results of the analysis may change, as more data is made available.« less

  5. Natural aphrodisiacs.

    PubMed

    Shamloul, Rany

    2010-01-01

    The search for a remedy or a prescription that can enhance sexual function and/or treat male erectile dysfunction has been an obsession throughout known history. Whether it was an Eastern civilization or a Western one, religious or atheist, man's aspiration for a better or best "manhood" has been a history-time goal. This review will discuss the current research done on the most popular natural aphrodisiacs and examine the weight of evidence to support or discourage the use of any of these substances to enhance sexual desire and/or function. Review of the current evidence on the use of natural substances as aphrodisiacs. Efficacy of natural aphrodisiacs in enhancing sexual function in men and women. There is little evidence from literature to recommend the usage of natural aphrodisiacs for the enhancement of sexual desire and/or performance. Data on yohimbine's efficacy does not support the wide use of the drug, which has only mild effects in the treatment of psychogenic ED. Although there's a positive trend towards recommending ginseng as an effective aphrodisiac, however, more in depth studies involving large number of subjects and its mechanism of action are needed before definite conclusions could be reached. Data on the use of natural aphrodisiacs in women is limited. The current body of objective evidence does not support the use of any natural aphrodisiac as an effective treatment for male or female sexual dysfunctions. Potent men and men with ED will continue the search for natural aphrodisiacs despite the current disappointing data on their effectiveness. Care should be taken regarding the fraud addition of sildenafil analogues to natural aphrodisiacs.

  6. Inner Ear Morphology in the Atlantic Molly Poecilia mexicana—First Detailed Microanatomical Study of the Inner Ear of a Cyprinodontiform Species

    PubMed Central

    Schulz-Mirbach, Tanja; Heß, Martin; Plath, Martin

    2011-01-01

    Background Fishes show an amazing diversity in hearing abilities, inner ear structures, and otolith morphology. Inner ear morphology, however, has not yet been investigated in detail in any member of the diverse order Cyprinodontiformes. We, therefore, studied the inner ear of the cyprinodontiform freshwater fish Poecilia mexicana by analyzing the position of otoliths in situ, investigating the 3D structure of sensory epithelia, and examining the orientation patterns of ciliary bundles of the sensory hair cells, while combining μ-CT analyses, scanning electron microscopy, and immunocytochemical methods. P. mexicana occurs in different ecotypes, enabling us to study the intra-specific variability (on a qualitative basis) of fish from regular surface streams, and the Cueva del Azufre, a sulfidic cave in southern Mexico. Results The inner ear of Poecilia mexicana displays a combination of several remarkable features. The utricle is connected rostrally instead of dorso-rostrally to the saccule, and the macula sacculi, therefore, is very close to the utricle. Moreover, the macula sacculi possesses dorsal and ventral bulges. The two studied ecotypes of P. mexicana showed variation mainly in the shape and curvature of the macula lagenae, in the curvature of the macula sacculi, and in the thickness of the otolithic membrane. Conclusions Our study for the first time provides detailed insights into the auditory periphery of a cyprinodontiform inner ear and thus serves a basis—especially with regard to the application of 3D techniques—for further research on structure-function relationships of inner ears within the species-rich order Cyprinodontiformes. We suggest that other poeciliid taxa, or even other non-poeciliid cyprinodontiforms, may display similar inner ear morphologies as described here. PMID:22110746

  7. Behavioral response of two species of stingless bees and the honey bee (Hymenoptera: Apidae) to GF-120.

    PubMed

    Gómez-Escobar, Enoc; Liedo, Pablo; Montoya, Pablo; Vandame, Rémy; Sánchez, Daniel

    2014-08-01

    We present the results of evaluating the response of three species of bees, Trigona fulviventris (Guérin), Scaptotrigona mexicana (Guérin-Meneville), and Apis mellifera (L.), to food sources baited with the toxic bait GF-120 (NF Naturalyte), a spinosad-based bait exclusively used to manage fruit flies. Groups of foragers were trained to collect honey and water from a feeder located 50 m from the colonies. Once a sufficient number of foragers were observed at the experimental location, the training feeder was changed to two or three feeders that offered either honey and water, GF-120, Captor (hydrolyzed protein), GF-120 and honey (4:6), or Captor and honey (1:19). T fulviventris and S. mexicana rarely visited GF-120, Captor, or their mixtures with honey, while approximately 28.5 and 1.5% of A. mellifera foragers visited the GF-120 and honey and Captor and honey mixtures, respectively. Our results show that GF-120 clearly repels T. fulviventris and S. mexicana, whereas for A. mellifera, repellence is not as marked when GF-120 is combined with highly nutritious substances like honey.

  8. Molecular Identification of Leishmania spp. in Sand Flies (Diptera: Psychodidae, Phlebotominae) From Ecuador.

    PubMed

    Quiroga, Cristina; Cevallos, Varsovia; Morales, Diego; Baldeón, Manuel E; Cárdenas, Paúl; Rojas-Silva, Patricio; Ponce, Patricio

    2017-11-07

    The detection and identification of natural infections in sand flies by Leishmania protozoan species in endemic areas is a key factor in assessing the risk of leishmaniasis and in designing prevention and control measures for this infectious disease. In this study, we analyzed the Leishmania DNA using nuclear ribosomal internal transcript spacer (ITS) sequences. Parasite DNA was extracted from naturally infected, blood-fed sand flies collected in nine localities considered leishmaniasis-endemic foci in Ecuador.The species of parasites identified in sand flies were Leishmania major-like, Leishmania naiffi, Leishmania mexicana, Leishmania lainsoni, and "Leishmania sp. siamensis". Sand fly specimens of Brumptomyia leopoldoi, Mycropigomyia cayennensis, Nyssomyia yuilli yuilli, Nyssomyia trapidoi, Pressatia triacantha, Pressatia dysponeta, Psychodopygus carrerai carrerai, Psychodopygus panamensis, and Trichophoromyia ubiquitalis were found positive for Leishmania parasite. These findings contribute to a better understanding of the epidemiology and transmission dynamics of the disease in high-risk areas of Ecuador. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  9. Molecular Identification of Leishmania spp. in Sand Flies (Diptera: Psychodidae, Phlebotominae) From Ecuador

    PubMed Central

    Cevallos, Varsovia; Morales, Diego; Baldeón, Manuel E; Cárdenas, Paúl; Rojas-Silva, Patricio; Ponce, Patricio

    2017-01-01

    Abstract The detection and identification of natural infections in sand flies by Leishmania protozoan species in endemic areas is a key factor in assessing the risk of leishmaniasis and in designing prevention and control measures for this infectious disease. In this study, we analyzed the Leishmania DNA using nuclear ribosomal internal transcript spacer (ITS) sequences. Parasite DNA was extracted from naturally infected, blood-fed sand flies collected in nine localities considered leishmaniasis-endemic foci in Ecuador. The species of parasites identified in sand flies were Leishmania major-like, Leishmania naiffi, Leishmania mexicana, Leishmania lainsoni, and “Leishmania sp. siamensis”. Sand fly specimens of Brumptomyia leopoldoi, Mycropigomyia cayennensis, Nyssomyia yuilli yuilli, Nyssomyia trapidoi, Pressatia triacantha, Pressatia dysponeta, Psychodopygus carrerai carrerai, Psychodopygus panamensis, and Trichophoromyia ubiquitalis were found positive for Leishmania parasite. These findings contribute to a better understanding of the epidemiology and transmission dynamics of the disease in high-risk areas of Ecuador. PMID:28981860

  10. Natural and near natural tropical forest values

    Treesearch

    Daniel H. Henning

    2011-01-01

    This paper identifies and describes some of the values associated with tropical rain forests in their natural and near-natural conditions. Tropical rain forests are moist forests in the humid tropics where temperature and rainfall are high and the dry season is short. These closed (non-logged) and broad-leaved forests are a global resource. Located almost entirely in...

  11. La Artesania Mexicana (Mexican Handicrafts).

    ERIC Educational Resources Information Center

    Steele, Bettina

    This booklet contains instructions in English and Spanish for making eleven typical Mexican craft articles. The instructions are accompanied by pen-and-ink drawings. The objects are (1) "La Rosa" (The Rose); (2) "El Crisantemo" (The Chrysanthemum); (3) "La Amapola" (The Poppy); (4) "Ojos de Dios" (God's Eyes); (5) "Ojitos con dos caras" (Two-Sided…

  12. Hepatoprotective natural triterpenoids.

    PubMed

    Xu, Guo-Bo; Xiao, Yao-Hua; Zhang, Qing-Yan; Zhou, Meng; Liao, Shang-Gao

    2018-02-10

    Liver diseases are one of the leading causes of death in the world. In spite of tremendous advances in modern drug research, effective and safe hepatoprotective agents are still in urgent demand. Natural products are undoubtedly valuable sources for drug leads. A number of natural triterpenoids were reported to possess pronounced hepatoprotective effects, and triterpenoids have become one of the most important classes of natural products for hepatoprotective agents. However, the significance of natural triterpenoids has been underestimated in the hepatoprotective drug discovery, with only very limited triterpenoids being covered in the reviews of hepatoprotective natural products. In this paper, ca 350 natural triterpenoids with reported hepatoprotective effects in ca 120 references between 1975 and 2016 will be reviewed, and the structure-activity relationships of certain types of natural triterpenoids, if available, will be discussed. Patents are not included. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  13. 18 CFR 2.78 - Utilization and conservation of natural resources-natural gas.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... conservation of natural resources-natural gas. 2.78 Section 2.78 Conservation of Power and Water Resources... INTERPRETATIONS Statements of General Policy and Interpretations Under the Natural Gas Act § 2.78 Utilization and conservation of natural resources—natural gas. (a)(1) The national interests in the development and utilization...

  14. Better than Nature: Nicotinamide Biomimetics That Outperform Natural Coenzymes.

    PubMed

    Knaus, Tanja; Paul, Caroline E; Levy, Colin W; de Vries, Simon; Mutti, Francesco G; Hollmann, Frank; Scrutton, Nigel S

    2016-01-27

    The search for affordable, green biocatalytic processes is a challenge for chemicals manufacture. Redox biotransformations are potentially attractive, but they rely on unstable and expensive nicotinamide coenzymes that have prevented their widespread exploitation. Stoichiometric use of natural coenzymes is not viable economically, and the instability of these molecules hinders catalytic processes that employ coenzyme recycling. Here, we investigate the efficiency of man-made synthetic biomimetics of the natural coenzymes NAD(P)H in redox biocatalysis. Extensive studies with a range of oxidoreductases belonging to the "ene" reductase family show that these biomimetics are excellent analogues of the natural coenzymes, revealed also in crystal structures of the ene reductase XenA with selected biomimetics. In selected cases, these biomimetics outperform the natural coenzymes. "Better-than-Nature" biomimetics should find widespread application in fine and specialty chemicals production by harnessing the power of high stereo-, regio-, and chemoselective redox biocatalysts and enabling reactions under mild conditions at low cost.

  15. A Coupled Human-Natural Systems Approach to Valuing Natural Capital

    NASA Astrophysics Data System (ADS)

    Fenichel, E. P.; Abbott, J.; Fujitani, M.

    2012-12-01

    The idea that geological and biological natural resources provide ecosystem services and that the physical geological and biological stocks, referred to as ecological stocks, are forms of capital is not new, but has attracted increased attention since the Millennium Ecosystem Assessment was released in 2005. Yet, the exact meaning of these terms, the connection between natural capital and ecosystem services, and the broader links between biophysical science and economics is often vague. The conceptual connection between ecosystem services and natural capital is that ecosystem services are the flow of goods and services that people receive from natural resources, and these flows are generated by an endowment of ecological stocks. While individuals derive benefits from a flow of services, the extent that people value the underlying natural capital asset depends on institutional arrangements in addition to the ecological properties of the stocks, because the value of capital relates to the future flow of services. A coupled human-natural systems modeling approach can help understand the value of natural capital in addition to helping scientist and policy makers better manage earth's resources. The value of a capital asset is the net present value of the flow of service, often calculated by the NPV rule. The NPV rule almost always assumes perfectly functioning markets for services and capital, but for many important ecosystem services such markets simply do not exist. The NPV rule can be derived by maximizing the net present value of capital. Indeed, the NPV rule comes from the adjoint condition of an optimal control problem where the flow of services from the capital asset are the benefits, and the dynamics of the capital stock are the constraints. Yet, trying to apply the traditional NPV rule to ecosystem services and natural capital can be frustrated by not knowing where pieces of the puzzle fit. We compare the standard NPV rule with a modified NPV rule derived by

  16. Wonderful secrets of nature. Natural knowledge and religious piety in Reformation Germany.

    PubMed

    Crowther-Heyck, Kathleen

    2003-06-01

    Sixteenth-century Germany witnessed a tremendous flourishing of vernacular literature. An unprecedented number and variety of texts were produced for new groups of readers. This essay analyzes one underexplored genre of this vernacular literature: texts on the natural world. Numerous books on animals, plants, minerals, and natural marvels rolled off the German presses in this period, indicating a widespread curiosity about the natural world. These texts give valuable insight into the views of nature available to a broad lay audience, literate in German but not necessarily in Latin. They reveal a pervasive sense of nature as divinely created and a deep conviction that contemplation of the natural world would lead to greater piety. The divine and the mundane were thoroughly intertwined in vernacular natural histories. While other historians of science have seen the sixteenth century as a period of increasingly secular ways of thinking about nature, I argue for the persistence, and even the intensification, of profoundly religious attitudes toward the natural world.

  17. Natural Language Processing.

    ERIC Educational Resources Information Center

    Chowdhury, Gobinda G.

    2003-01-01

    Discusses issues related to natural language processing, including theoretical developments; natural language understanding; tools and techniques; natural language text processing systems; abstracting; information extraction; information retrieval; interfaces; software; Internet, Web, and digital library applications; machine translation for…

  18. Nature gives us strength: exposure to nature counteracts ego-depletion.

    PubMed

    Chow, Jason T; Lau, Shun

    2015-01-01

    Previous research rarely investigated the role of physical environment in counteracting ego-depletion. In the present research, we hypothesized that exposure to natural environment counteracts ego-depletion. Three experiments were conducted to test this hypothesis. In Experiment 1, initially depleted participants who viewed pictures of nature scenes showed greater persistence on a subsequent anagram task than those who were given a rest period. Experiment 2 expanded upon this finding by showing that natural environment enhanced logical reasoning performance after ego-depleting task. Experiment 3 adopted a two- (depletion vs. no-depletion) -by-two (nature exposure vs. urban exposure) factorial design. We found that nature exposure moderated the effect of depletion on anagram task performance. Taken together, the present studies offer a viable and novel strategy to mitigate the negative impacts of ego-depletion.

  19. Connection to Nature: Children's Affective Attitude toward Nature

    ERIC Educational Resources Information Center

    Cheng, Judith Chen-Hsuan; Monroe, Martha C.

    2012-01-01

    A connection to nature index was developed and tested to measure children's affective attitude toward the natural environment. The index was employed through a survey that investigates students' attitude toward Lagoon Quest, a mandatory environmental education program for all fourth-grade, public school students in Brevard County, Florida. Factor…

  20. New methods for assessing the fascinating nature of nature experiences.

    PubMed

    Joye, Yannick; Pals, Roos; Steg, Linda; Evans, Ben Lewis

    2013-01-01

    In recent years, numerous environmental psychology studies have demonstrated that contact with nature as opposed to urban settings can improve an individual's mood, can lead to increased levels of vitality, and can offer an opportunity to recover from stress. According to Attention Restoration Theory (ART) the restorative potential of natural environments is situated in the fact that nature can replenish depleted attentional resources. This replenishment takes place, in part, because nature is deemed to be a source of fascination, with fascination being described as having an "attentional", an "affective" and an "effort" dimension. However, the claim that fascination with nature involves these three dimensions is to a large extent based on intuition or derived from introspection-based measurement methods, such as self-reports. In three studies, we aimed to more objectively assess whether these three dimensions indeed applied to experiences related to natural environments, before any (attentional) depletion has taken place. The instruments that were used were: (a) the affect misattribution procedure (Study 1), (b) the dot probe paradigm (Study 2) and (c) a cognitively effortful task (Study 3). These instrument were respectively aimed at verifying the affective, attentional and effort dimension of fascination. Overall, the results provide objective evidence for the claims made within the ART framework, that natural as opposed to urban settings are affectively positive (cfr., affective dimension) and that people have an attentional bias to natural (rather than urban) environments (cfr., attentional dimension). The results regarding the effort dimension are less straightforward, and suggest that this dimension only becomes important in sufficiently difficult cognitive tasks.

  1. U.S. Natural Gas Markets: Mid-Term Prospects for Natural Gas Supply

    EIA Publications

    2001-01-01

    This service report describes the recent behavior of natural gas markets with respect to natural gas prices, their potential future behavior, the potential future supply contribution of liquefied natural gas and increased access to federally restricted resources, and the need for improved natural gas data.

  2. Unnaturalised racial naturalism.

    PubMed

    Hochman, Adam

    2014-06-01

    Quayshawn Spencer (2014) misunderstands my treatment of racial naturalism. I argued that racial naturalism must entail a strong claim, such as "races are subspecies", if it is to be a substantive position that contrasts with anti-realism about biological race. My recognition that not all race naturalists make such a strong claim is evident throughout the article Spencer reviews (Hochman, 2013a). Spencer seems to agree with me that there are no human subspecies, and he endorses a weaker form of racial naturalism. However, he supports his preferred version of 'racial naturalism' with arguments that are not well described as 'naturalistic'. I argue that Spencer offers us an unnaturalised racial naturalism. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Distinguishing between extra natural inflation and natural inflation after BICEP2

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kohri, Kazunori; Lim, C.S.; Lin, Chia-Min, E-mail: kohri@post.kek.jp, E-mail: lim@lab.twcu.ac.jp, E-mail: lin@chuo-u.ac.jp

    2014-08-01

    In this paper, we carefully calculated the tensor-to-scalar ratio, the running spectral index, and the running of running spectrum for (extra) natural inflation in order to compare with recent BICEP2 data, PLANCK satellite data and future 21 cm data. We discovered that the prediction for running spectral index and the running of running spectrum in natural inflation is different from that in the case of extra natural inflation. Near future observation for the running spectral index can only provide marginal accuracy which may not allow us distinguishing between extra natural inflation from natural inflation clearly unless the experimental accuracy canmore » be further improved.« less

  4. Natural Gas Basics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    2016-06-08

    Natural gas powers about 150,000 vehicles in the United States and roughly 22 million vehicles worldwide. Natural gas vehicles (NGVs) are a good choice for high-mileage fleets -- such as buses, taxis, and refuse vehicles -- that are centrally fueled or operate within a limited area or along a route with natural gas fueling stations. This brochure highlights the advantages of natural gas as an alternative fuel, including its domestic availability, established distribution network, relatively low cost, and emissions benefits.

  5. Natural Gas Basics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    2016-06-01

    Natural gas powers about 150,000 vehicles in the United States and roughly 22 million vehicles worldwide. Natural gas vehicles (NGVs) are a good choice for high-mileage fleets -- such as buses, taxis, and refuse vehicles -- that are centrally fueled or operate within a limited area or along a route with natural gas fueling stations. This brochure highlights the advantages of natural gas as an alternative fuel, including its domestic availability, established distribution network, relatively low cost, and emissions benefits.

  6. New Methods for Assessing the Fascinating Nature of Nature Experiences

    PubMed Central

    Joye, Yannick; Pals, Roos; Steg, Linda; Evans, Ben Lewis

    2013-01-01

    In recent years, numerous environmental psychology studies have demonstrated that contact with nature as opposed to urban settings can improve an individual’s mood, can lead to increased levels of vitality, and can offer an opportunity to recover from stress. According to Attention Restoration Theory (ART) the restorative potential of natural environments is situated in the fact that nature can replenish depleted attentional resources. This replenishment takes place, in part, because nature is deemed to be a source of fascination, with fascination being described as having an “attentional”, an “affective” and an “effort” dimension. However, the claim that fascination with nature involves these three dimensions is to a large extent based on intuition or derived from introspection-based measurement methods, such as self-reports. In three studies, we aimed to more objectively assess whether these three dimensions indeed applied to experiences related to natural environments, before any (attentional) depletion has taken place. The instruments that were used were: (a) the affect misattribution procedure (Study 1), (b) the dot probe paradigm (Study 2) and (c) a cognitively effortful task (Study 3). These instrument were respectively aimed at verifying the affective, attentional and effort dimension of fascination. Overall, the results provide objective evidence for the claims made within the ART framework, that natural as opposed to urban settings are affectively positive (cfr., affective dimension) and that people have an attentional bias to natural (rather than urban) environments (cfr., attentional dimension). The results regarding the effort dimension are less straightforward, and suggest that this dimension only becomes important in sufficiently difficult cognitive tasks. PMID:23922645

  7. SuperNatural: a searchable database of available natural compounds

    PubMed Central

    Dunkel, Mathias; Fullbeck, Melanie; Neumann, Stefanie; Preissner, Robert

    2006-01-01

    Although tremendous effort has been put into synthetic libraries, most drugs on the market are still natural compounds or derivatives thereof. There are encyclopaedias of natural compounds, but the availability of these compounds is often unclear and catalogues from numerous suppliers have to be checked. To overcome these problems we have compiled a database of ∼50 000 natural compounds from different suppliers. To enable efficient identification of the desired compounds, we have implemented substructure searches with typical templates. Starting points for in silico screenings are about 2500 well-known and classified natural compounds from a compendium that we have added. Possible medical applications can be ascertained via automatic searches for similar drugs in a free conformational drug database containing WHO indications. Furthermore, we have computed about three million conformers, which are deployed to account for the flexibilities of the compounds when the 3D superposition algorithm that we have developed is used. The SuperNatural Database is publicly available at . Viewing requires the free Chime-plugin from MDL (Chime) or Java2 Runtime Environment (MView), which is also necessary for using Marvin application for chemical drawing. PMID:16381957

  8. SuperNatural: a searchable database of available natural compounds.

    PubMed

    Dunkel, Mathias; Fullbeck, Melanie; Neumann, Stefanie; Preissner, Robert

    2006-01-01

    Although tremendous effort has been put into synthetic libraries, most drugs on the market are still natural compounds or derivatives thereof. There are encyclopaedias of natural compounds, but the availability of these compounds is often unclear and catalogues from numerous suppliers have to be checked. To overcome these problems we have compiled a database of approximately 50,000 natural compounds from different suppliers. To enable efficient identification of the desired compounds, we have implemented substructure searches with typical templates. Starting points for in silico screenings are about 2500 well-known and classified natural compounds from a compendium that we have added. Possible medical applications can be ascertained via automatic searches for similar drugs in a free conformational drug database containing WHO indications. Furthermore, we have computed about three million conformers, which are deployed to account for the flexibilities of the compounds when the 3D superposition algorithm that we have developed is used. The SuperNatural Database is publicly available at http://bioinformatics.charite.de/supernatural. Viewing requires the free Chime-plugin from MDL (Chime) or Java2 Runtime Environment (MView), which is also necessary for using Marvin application for chemical drawing.

  9. Andean cutaneous leishmaniasis (Andean-CL, uta) in Peru and Ecuador: the vector Lutzomyia sand flies and reservoir mammals.

    PubMed

    Hashiguchi, Yoshihisa; Gomez L, Eduardo A; Cáceres, Abraham G; Velez, Lenin N; Villegas, Nancy V; Hashiguchi, Kazue; Mimori, Tatsuyuki; Uezato, Hiroshi; Kato, Hirotomo

    2018-02-01

    The vector Lutzomyia sand flies and reservoir host mammals of the Leishmania parasites, causing the Andean cutaneous leishmaniasis (Andean-CL, uta) in Peru and Ecuador were thoroughly reviewed, performing a survey of literatures including our unpublished data. The Peruvian L. (V.) peruviana, a principal Leishmania species causing Andean-CL in Peru, possessed three Lutzomyia species, Lu. peruensis, Lu. verrucarum and Lu. ayacuchensis as vectors, while the Ecuadorian L. (L.) mexicana parasite possessed only one species Lu. ayacuchensis as the vector. Among these, the Ecuadorian showed a markedly higher rate of natural Leishmania infections. However, the monthly and diurnal biting activities were mostly similar among these vector species was in both countries, and the higher rates of infection (transmission) reported, corresponded to sand fly's higher monthly-activity season (rainy season). The Lu. tejadai sand fly participated as a vector of a hybrid parasite of L. (V.) braziliensis/L. (V.) peruviana in the Peruvian Andes. Dogs were considered to be principal reservoir hosts of the L. (V.) peruviana and L. (L.) mexicana parasites in both countries, followed by other sylvatic mammals such as Phyllotis andium, Didelphis albiventris and Akodon sp. in Peru, and Rattus rattus in Ecuador, but information on the reservoir hosts/mammals was extremely poor in both countries. Thus, the Peruvian disease form demonstrated more complicated transmission dynamics than the Ecuadorian. A brief review was also given to the control of vector and reservoirs in the Andes areas. Such information is crucial for future development of the control strategies of the disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Natural-Product-Derived Carbon Dots: From Natural Products to Functional Materials.

    PubMed

    Zhang, Xinyue; Jiang, Mingyue; Niu, Na; Chen, Zhijun; Li, Shujun; Liu, Shouxin; Li, Jian

    2018-01-10

    Nature provides an almost limitless supply of sources that inspire scientists to develop new materials with novel applications and less of an environmental impact. Recently, much attention has been focused on preparing natural-product-derived carbon dots (NCDs), because natural products have several advantages. First, natural products are renewable and have good biocompatibility. Second, natural products contain heteroatoms, which facilitate the fabrication of heteroatom-doped NCDs without the addition of an external heteroatom source. Finally, some natural products can be used to prepare NCDs in ways that are very green and simple relative to traditional methods for the preparation of carbon dots from man-made carbon sources. NCDs have shown tremendous potential in many fields, including biosensing, bioimaging, optoelectronics, and photocatalysis. This Review addresses recent progress in the synthesis, properties, and applications of NCDs. The challenges and future direction of research on NCD-based materials in this booming field are also discussed. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. On nature and bioethics.

    PubMed

    Peterson, Paul Silas

    2010-01-01

    The account of nature and humanity's relationship to nature are of central importance for bioethics. The Scientific Revolution was a critical development in the history of this question and many contemporary accounts of nature find their beginnings here. While the innovative approach to nature going out of the seventeenth century was reliant upon accounts of nature from the early modern period, the Middle Ages, late-antiquity and antiquity, it also parted ways with some of the understandings of nature from these epochs. Here I analyze this development and suggests that some of the insights from older understandings of nature may be helpful for bioethics today, even if there can be no simple return to them.

  12. Matematica Natural.

    ERIC Educational Resources Information Center

    Lozano, Patricia; Medearis, Linda

    Matematica Natural (Natural Mathematics) is a mathematics curriculum for young children based on the assumption that they learn mathematics through concrete, real life, relevant experiences and that educational differences rather than cultural differences influence math achievement. The curriculum uses hands-on materials and activities to teach…

  13. Phylogeny of the genus Pistacia as determined from analysis of the chloroplast genome

    PubMed Central

    Parfitt, Dan E.; Badenes, Maria L.

    1997-01-01

    Classification within the genus Pistacia has been based on leaf morphology and geographical distribution. Molecular genetic tools (PCR amplification followed by restriction analysis of a 3.2-kb region of variable chloroplast DNA, and restriction fragment length polymorphism analysis of the Pistacia cpDNA with tobacco chloroplast DNA probes) provided a new set of variables to study the phylogenetic relationships of 10 Pistacia species. Both parsimony and cluster analyses were used to divide the genus into two major groups. P. vera was determined to be the least derived species. P. weinmannifolia, an Asian species, is most closely related to P. texana and P. mexicana, New World species. These three species share a common origin, suggesting that a common ancestor of P. texana and P. mexicana originated in Asia. P. integerrima and P. chinensis were shown to be distinct whereas the pairs of species were monophyletic within each of two tertiary groups, P. vera:P. khinjuk and P. mexicana:P. texana. An evolutionary trend from large to small nuts and leaves with few, large leaflets to many, small leaflets was supported. The genus Pistacia was shown to have a low chloroplast DNA mutation rate: 0.05–0.16 times that expected of annual plants. PMID:9223300

  14. Life on the edge: hydrogen sulfide and the fish communities of a Mexican cave and surrounding waters.

    PubMed

    Tobler, Michael; Schlupp, Ingo; Heubel, Katja U; Riesch, Rüdiger; de León, Francisco J García; Giere, Olav; Plath, Martin

    2006-12-01

    Most eucaryotic organisms classified as living in an extreme habitat are invertebrates. Here we report of a fish living in a Mexican cave (Cueva del Azufre) that is rich in highly toxic H(2)S. We compared the water chemistry and fish communities of the cave and several nearby surface streams. Our study revealed high concentrations of H(2)S in the cave and its outflow (El Azufre). The concentrations of H(2)S reach more than 300 muM inside the cave, which are acutely toxic for most fishes. In both sulfidic habitats, the diversity of fishes was heavily reduced, and Poecilia mexicana was the dominant species indicating that the presence of H(2)S has an all-or-none effect, permitting only few species to survive in sulfidic habitats. Compared to habitats without H(2)S, P. mexicana from the cave and the outflow have a significantly lower body condition. Although there are microhabitats with varying concentrations of H(2)S within the cave, we could not find a higher fish density in areas with lower concentrations of H(2)S. We discuss that P. mexicana is one of the few extremophile vertebrates. Our study supports the idea that extreme habitats lead to an impoverished species diversity.

  15. The Anthropocene, Ethics, and the Nature of Nature

    NASA Astrophysics Data System (ADS)

    Trachtenberg, Z.

    2012-12-01

    For Earth scientists the Anthropocene has a strict meaning, tied to evidence that human activities have produced pervasive impacts on the Earth. But it is also significant for scholars outside the Earth sciences. Social scientists study the ways human societies transform the landscape to make it more suited to human habitation; the Anthropocene idea has already served to reveal conceptual linkages among physical and social science research programs. And the Anthropocene has important implications for normative theorists who enquire into the basis of ethical standards that, ideally, guide human activities within the environment. An influential view has held the condition of the Earth's systems in the absence of human interference as such a standard. This view emphasizes the preservation of environmental systems in (or restoration to) their "natural" condition—either because that condition is the most advantageous for human beings, or because those systems have an intrinsic moral value human beings ought to respect. However, Anthropocene research destabilizes the concept of nature. For the "natural" is typically opposed to the artificial, i.e. to the results of human action, and although nature obviously provides the context for human activity, that context is taken to be exogenously given. For virtually all of Earth's history, its systems were "natural" in this sense. However, since the appearance of life on Earth, organisms engaging in what is called niche construction have fundamentally transformed those systems up to the planetary scale. There is no reason to regard human niche construction (e.g. agriculture) as different in kind—though of course anthropogenic impacts are greater than the impacts of other species. It follows that the Anthropocene demands that we move away from an outlook based on a strict opposition between a "natural" condition and the human activities which change it, towards one that conceives of the natural not as a condition, but as a

  16. Francis Bacon's natural history and the Senecan natural histories of early modern Europe.

    PubMed

    Jalobeanu, Dana

    2012-01-01

    At various stages in his career, Francis Bacon claimed to have reformed and changed traditional natural history in such a way that his new "natural and experimental history" was unlike any of its ancient or humanist predecessors. Surprisingly, such claims have gone largely unquestioned in Baconian scholarship. Contextual readings of Bacon's natural history have compared it, so far, only with Plinian or humanist natural history. This paper investigates a different form of natural history, very popular among Bacon's contemporaries, but yet unexplored by contemporary students of Bacon's works. I have provisionally called this form of natural history'Senecan' natural history, partly because it took shape in the Neo-Stoic revival of the sixteenth-century, partly because it originates in a particular cosmographical reading of Seneca's Naturales quaestiones. I discuss in this paper two examples of Senecan natural history: the encyclopedic and cosmographical projects of Pierre de la Primaudaye (1546-1619) and Samuel Purchas (1577-1626). I highlight a number of similarities between these two projects and Francis Bacon's natural history, and argue that Senecan natural history forms an important aspect in the historical and philosophical background that needs to be taken into consideration if we want to understand the extent to which Bacon's project to reform natural history can be said to be new.

  17. Within city limits: nature and children's books about nature in the city

    Treesearch

    Leonard S. Marcus

    1977-01-01

    Many children's books give the impression that we must leave the city to be "in nature.'' This is a review of children's books about nature found within city limits. The books include a natural history of New York City; a guide to city wildflowers and other weeds; a book about city trees; a delightful inquiry into the true nature of the roach;...

  18. Evolutionary history of Mexican domesticated and wild Meleagris gallopavo.

    PubMed

    Padilla-Jacobo, Gabriela; Cano-Camacho, Horacio; López-Zavala, Rigoberto; Cornejo-Pérez, María E; Zavala-Páramo, María G

    2018-04-17

    The distribution of the wild turkey (Meleagris gallopavo) extends from Mexico to southeastern Canada and to the eastern and southern regions of the USA. Six subspecies have been described based on morphological characteristics and/or geographical variations in wild and domesticated populations. In this paper, based on DNA sequence data from the mitochondrial D-loop, we investigated the genetic diversity and structure, genealogical relationships, divergence time and demographic history of M. gallopavo populations including domesticated individuals. Analyses of 612 wild and domesticated turkey mitochondrial D-loop sequences, including 187 that were collected for this study and 425 from databases, revealed 64 haplotypes with few mutations, some of which are shared between domesticated and wild turkeys. We found a high level of haplotype and nucleotide diversity, which suggests that the total population of this species is large and stable with an old evolutionary history. The results of genetic differentiation, haplotype network, and genealogical relationships analyses revealed three main genetic groups within the species: mexicana as a population relict (C1), merriami (C2), and mexicana/intermedia/silvestris/osceola (C3). Haplotypes detected in domesticated turkeys belong to group C3. Estimates of divergence times agree with range expansion and diversification events of the relict population of M. gallopavo in northwestern Mexico during the Pliocene-Pleistocene and Pleistocene-Holocene boundaries. Demographic reconstruction showed that an expansion of the population occurred 110,000 to 130,000 years ago (Kya), followed by a stable period 100 Kya and finally a decline ~ 10 Kya (Pleistocene-Holocene boundary). In Mexico, the Trans-Mexican Volcanic Belt may be responsible for the range expansion of the C3 group. Two haplotypes with different divergence times, MGMDgoB/MICH1 and MICH2, are dominant in domesticated and commercial turkeys. During the Pleistocene, a

  19. Defining Nature-Based Preschools

    ERIC Educational Resources Information Center

    Larimore, Rachel

    2016-01-01

    Nature-based early childhood education. Nature-based preschool. Nature preschool. Forest kindergarten. Nature kindergarten. Waldkindergarten. Forest school. These are a few of the program terms currently being discussed among early childhood environmental education professionals in the United States. Why is there so much discussion about the names…

  20. Better than Nature: Nicotinamide Biomimetics That Outperform Natural Coenzymes

    PubMed Central

    2016-01-01

    The search for affordable, green biocatalytic processes is a challenge for chemicals manufacture. Redox biotransformations are potentially attractive, but they rely on unstable and expensive nicotinamide coenzymes that have prevented their widespread exploitation. Stoichiometric use of natural coenzymes is not viable economically, and the instability of these molecules hinders catalytic processes that employ coenzyme recycling. Here, we investigate the efficiency of man-made synthetic biomimetics of the natural coenzymes NAD(P)H in redox biocatalysis. Extensive studies with a range of oxidoreductases belonging to the “ene” reductase family show that these biomimetics are excellent analogues of the natural coenzymes, revealed also in crystal structures of the ene reductase XenA with selected biomimetics. In selected cases, these biomimetics outperform the natural coenzymes. “Better-than-Nature” biomimetics should find widespread application in fine and specialty chemicals production by harnessing the power of high stereo-, regio-, and chemoselective redox biocatalysts and enabling reactions under mild conditions at low cost. PMID:26727612

  1. Nephrotoxicity of Natural Products.

    PubMed

    Nauffal, Mary; Gabardi, Steven

    2016-01-01

    The manufacture and sale of natural products constitute a multi-billion dollar industry. Nearly a third of the American population admit to using some form of complementary or alternative medicine, with many using them in addition to prescription medications. Most patients fail to inform their healthcare providers of their natural product use and physicians rarely inquire. Annually, thousands of natural product-induced adverse events are reported to Poison Control Centers nationwide. Natural product manufacturers are not responsible for proving safety and efficacy, as the FDA does not regulate them. However, concerns exist surrounding the safety of natural products. This review provides details on natural products that have been associated with renal dysfunction. We have focused on products that have been associated with direct renal injury, immune-mediated nephrotoxicity, nephrolithiasis, rhabdomyolysis with acute renal injury, hepatorenal syndrome, and common adulterants or contaminants that are associated with renal dysfunction. The potential for natural products to cause renal dysfunction is justifiable. It is imperative that natural product use be monitored closely in all patients. Healthcare practitioners must play an active role in identifying patients using natural products and provide appropriate patient education. © 2016 S. Karger AG, Basel.

  2. Sharing Nature with Children: A Parents' and Teachers' Nature-awareness Guidebook.

    ERIC Educational Resources Information Center

    Cornell, Joseph Bharat

    The guidebook presents 42 educational games designed for people of all temperaments and intended to open up nature to children (ages 3 and up) and adults. The games are organized in seven major sections according to the type of activity: Close Up with Nature, How Much Can You See, Nature's Balance, Learning Is Fun, Play and Discovery, Spotting and…

  3. Beyond knowing nature: Contact, emotion, compassion, meaning, and beauty are pathways to nature connection

    PubMed Central

    Lumber, Ryan; Richardson, Miles; Sheffield, David

    2017-01-01

    Feeling connected to nature has been shown to be beneficial to wellbeing and pro-environmental behaviour. General nature contact and knowledge based activities are often used in an attempt to engage people with nature. However the specific routes to nature connectedness have not been examined systematically. Two online surveys (total n = 321) of engagement with, and value of, nature activities structured around the nine values of the Biophila Hypothesis were conducted. Contact, emotion, meaning, and compassion, with the latter mediated by engagement with natural beauty, were predictors of connection with nature, yet knowledge based activities were not. In a third study (n = 72), a walking intervention with activities operationalising the identified predictors, was found to significantly increase connection to nature when compared to walking in nature alone or walking in and engaging with the built environment. The findings indicate that contact, emotion, meaning, compassion, and beauty are pathways for improving nature connectedness. The pathways also provide alternative values and frames to the traditional knowledge and identification routes often used by organisations when engaging the public with nature. PMID:28486515

  4. Beyond knowing nature: Contact, emotion, compassion, meaning, and beauty are pathways to nature connection.

    PubMed

    Lumber, Ryan; Richardson, Miles; Sheffield, David

    2017-01-01

    Feeling connected to nature has been shown to be beneficial to wellbeing and pro-environmental behaviour. General nature contact and knowledge based activities are often used in an attempt to engage people with nature. However the specific routes to nature connectedness have not been examined systematically. Two online surveys (total n = 321) of engagement with, and value of, nature activities structured around the nine values of the Biophila Hypothesis were conducted. Contact, emotion, meaning, and compassion, with the latter mediated by engagement with natural beauty, were predictors of connection with nature, yet knowledge based activities were not. In a third study (n = 72), a walking intervention with activities operationalising the identified predictors, was found to significantly increase connection to nature when compared to walking in nature alone or walking in and engaging with the built environment. The findings indicate that contact, emotion, meaning, compassion, and beauty are pathways for improving nature connectedness. The pathways also provide alternative values and frames to the traditional knowledge and identification routes often used by organisations when engaging the public with nature.

  5. Firsthand Nature

    ERIC Educational Resources Information Center

    Gostev, Moses; Weiss, Francesca Michaelides

    2007-01-01

    It's no secret that many school programs don't give children enough opportunity to explore the natural world--i.e., to "mess about" and to have firsthand experience with nature and animals. Not so at the Muscota New School in New York City! This innovative public elementary school actively promotes inquiry-based learning and encourages…

  6. Modeling Child–Nature Interaction in a Nature Preschool: A Proof of Concept

    PubMed Central

    Kahn, Peter H.; Weiss, Thea; Harrington, Kit

    2018-01-01

    This article provides a proof of concept for an approach to modeling child–nature interaction based on the idea of interaction patterns: characterizations of essential features of interaction between humans and nature, specified abstractly enough such that countless different instantiations of each one can occur – in more domestic or wild forms – given different types of nature, people, and purposes. The model draws from constructivist psychology, ecological psychology, and evolutionary psychology, and is grounded in observational data collected through a time-sampling methodology at a nature preschool. Through using a nature language that emphasizes ontogenetic and phylogenetic significance, seven keystone interaction patterns are described for this nature preschool: using one’s body vigorously in nature, striking wood on wood, constructing shelter, being in solitude in nature, lying on earth, cohabiting with a wild animal, and being outside in weather. These 7 interactions patterns are then brought together with 13 other patterns published elsewhere to provide a total of 20 keystone interaction patterns that begin to fill out the model, and to show its promise. Discussion focuses on what the model aims to be in terms of both product and process, on what work the model can currently do, and how to further develop the model. PMID:29896143

  7. Modeling Child-Nature Interaction in a Nature Preschool: A Proof of Concept.

    PubMed

    Kahn, Peter H; Weiss, Thea; Harrington, Kit

    2018-01-01

    This article provides a proof of concept for an approach to modeling child-nature interaction based on the idea of interaction patterns : characterizations of essential features of interaction between humans and nature, specified abstractly enough such that countless different instantiations of each one can occur - in more domestic or wild forms - given different types of nature, people, and purposes. The model draws from constructivist psychology, ecological psychology, and evolutionary psychology, and is grounded in observational data collected through a time-sampling methodology at a nature preschool. Through using a nature language that emphasizes ontogenetic and phylogenetic significance, seven keystone interaction patterns are described for this nature preschool: using one's body vigorously in nature, striking wood on wood, constructing shelter, being in solitude in nature, lying on earth, cohabiting with a wild animal , and being outside in weather . These 7 interactions patterns are then brought together with 13 other patterns published elsewhere to provide a total of 20 keystone interaction patterns that begin to fill out the model, and to show its promise. Discussion focuses on what the model aims to be in terms of both product and process, on what work the model can currently do, and how to further develop the model.

  8. Nature Detectives

    ERIC Educational Resources Information Center

    Harr, Natalie; Lee, Richard E.; Jr.

    2010-01-01

    Richard Louv's "Last Child in the Woods" (2008) added to a growing consensus to get children outside and experiencing nature. Using ideas from place-based education, the authors present a simple year-long project that brings science, nature, and other curriculum standards to life right in your school yard. With a focus on journaling, this project…

  9. Assessing the competitive ability of Japanese stilt grass, Microstegium vimineum (Trin.) A. Camus

    USGS Publications Warehouse

    Leicht, S.A.; Silander, J.A.; Greenwood, K.

    2005-01-01

    Microstegium vimineum (Japanese stilt grass) is an invasive grass in the eastern half of the United States which can form dense monocultures in forest understories, displacing native species. Although the loss of native species has been observed in the field, the actual competitive ability of this grass has not been examined. Microstegium vimineum was grown under controlled environment, greenhouse conditions in competition with Lolium perenne ssp. multiflorum (annual rye grass) and Muhlenbergia mexicana (Mexican muhly) in varying density ratios in full and low light treatments. Microstegium vimineum had a greater aboveground biomass, relative growth rate, and reproductive output than both competitors in both light treatments. The high competitive ability of Microstegium vimineum, especially in low light conditions, reflects its highly aggressive nature in forested or other landscapes of eastern North America.

  10. US crude oil, natural gas, and natural gas liquids reserves 1996 annual report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1997-12-01

    The EIA annual reserves report series is the only source of comprehensive domestic proved reserves estimates. This publication is used by the Congress, Federal and State agencies, industry, and other interested parties to obtain accurate estimates of the Nation`s proved reserves of crude oil, natural gas, and natural gas liquids. These data are essential to the development, implementation, and evaluation of energy policy and legislation. This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1996, as well as production volumes for the US and selected States and State subdivisionsmore » for the year 1996. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), nonassociated gas and associated-dissolved gas (which are the two major types of wet natural gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, reserve estimates for two types of natural gas liquids, lease condensate and natural gas plant liquids, are presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1996 is provided. 21 figs., 16 tabs.« less

  11. Toxicological evaluation of the natural products and some semisynthetic derivatives of Heterotheca inuloides Cass (Asteraceae).

    PubMed

    Rodríguez-Chávez, José Luis; Coballase-Urrutia, Elvia; Sicilia-Argumedo, Gloria; Ramírez-Apan, Teresa; Delgado, Guillermo

    2015-12-04

    Heterotheca ineuloides Cass (Asteraceae), popularly known as árnica mexicana, is widely used in Mexican traditional medicine to treat bruises, dermatological problems, rheumatic pains, and other disorders as cancer. The major constituents in H. inuloides are cadinane type sesquiterpenes, flavonoids and phytosterols. Compounds with a cadinane skeleton have been proved to possess cytotoxic activity against human-tumor cell lines and brine shrimp, and display toxic effects in different animal species. Although this plant has been widely used, there is little available information on the safety and toxicity especially of pure compounds. Evaluate the potential toxicity of the natural products isolated from H. inuloides and some semisynthetic derivatives. The toxic aspects of the following natural products isolated from dried flowers of H. inuloides: 7-hydroxy-3,4-dihydrocadalene (1), 7-hydroxycadalene (2), 3,7-dihydroxy-3(4H)-isocadalen-4-one (3), (1R,4R)-1-hydroxy-4H-1,2,3,4- tetrahydrocadalen-15-oic acid (4), D-chiro-inositol (5), quercetin (6), quercetin-3,7,3'-trimethyl ether (7), quercetin-3,7,3',4'-tetramethyl ether (8), eriodictyol-7,4'-dimethyl ether (9), α-spinasterol (10), caryolan-1,9β-diol (11) and 7-(3,3-dimethylallyloxy)-coumarin (12) as well as the toxic aspects of the semisynthetic compounds 7-acetoxy-3,4-dihydrocadalene (13), 7-benzoxy-3,4-dihydrocadalene (14), 7-acetoxycadalene (15), 7-benzoxycadalene (16), quercetin pentaacetate (17), 7-hydroxycalamenene (18), 3,8-dimethyl-5-(1-methylethyl)-1,2-naphthoquinone (19), and 4-isopropyl-1,6-dimethylbenzo[c]oxepine-7,9-dione (20). Toxic activities of compounds were determined by sulforhodamine B (SRB) assay, Artemia salina assay, RAW264.7 macrophage cells. Additionally, the acute toxicity in mouse of compound 1, the major natural sesquiterpene isolated from the acetone extract, was evaluated. The best cytotoxicity activity was observed for mansonone C (19) on K562 cell line with IC50 1.45 ± 0.14 μM, for

  12. Natural vacuum electronics

    NASA Technical Reports Server (NTRS)

    Leggett, Nickolaus

    1990-01-01

    The ambient natural vacuum of space is proposed as a basis for electron valves. Each valve is an electron controlling structure similiar to a vacuum tube that is operated without a vacuum sustaining envelope. The natural vacuum electron valves discussed offer a viable substitute for solid state devices. The natural vacuum valve is highly resistant to ionizing radiation, system generated electromagnetic pulse, current transients, and direct exposure to space conditions.

  13. 76 FR 48880 - Endangered Species; Marine Mammals; Receipt of Applications for Permit

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-09

    ... from howler monkeys (Alouatta palliata mexicana, Alouatta pigra, and Alouatta palliata x Alouatta pigra... Mammals and Marine Mammals Applicant: Sea to Shore Alliance, Sarasota, FL; PRT-37808A The applicant...

  14. Community-level net spillover of natural enemies from managed to natural forest

    USDA-ARS?s Scientific Manuscript database

    Edge effects in fragmented natural habitats may be exacerbated by intensive land-use in the surrounding landscape. Given that most managed systems have higher productivity than adjacent natural systems, theory suggests that subsidised consumers are likely to spill over from managed to natural habita...

  15. The Ecology of Hope: Natural Guides to Building a Children and Nature Movement

    NASA Astrophysics Data System (ADS)

    Charles, Cheryl

    2009-12-01

    Cheryl Charles, Ph.D gave the 2009 Paul F-Brandwein Lecture. The lecture addresses the impact of children's disconnect from the natural world in their everyday lives. Co-founder of the Children & Nature Network (C&NN) with Richard Louv, author of Last Child in the Woods: Saving Our Children from Nature-Deficit Disorder (2005/2008), the author describes C&NN's approach to building a movement to reconnect children and nature for their health and well-being. She puts the growth of the movement in recent historical perspective, chronicling relevant contributing factors. Drawing on research as well as common sense, she summarizes evidence that indicates some of the negative impacts on children's health from their lack of contact with nature and other characteristics of contemporary lifestyles, as well as positive benefits to children's cognitive, emotional, social and physical development from direct learning and play in nature-based settings. She describes what she calls "natural guides" to building the children and nature movement as a part of the process of achieving sufficient critical mass to facilitate positive social change. Finally, she offers recommendations for actions.

  16. Natural Beauty

    ERIC Educational Resources Information Center

    Coy, Mary

    2006-01-01

    In this article, the author describes how her art class students were able to create, in just four class periods, clay relief plaques depicting nature. A lesson on texture speeds up the completion of such a project. Seeing that clay is a natural material with its own unique texture, it seemed fitting that the final product should depict a variety…

  17. Novel natural food antimicrobials.

    PubMed

    Juneja, Vijay K; Dwivedi, Hari P; Yan, Xianghe

    2012-01-01

    Naturally occurring antimicrobial compounds could be applied as food preservatives to protect food quality and extend the shelf life of foods and beverages. These compounds are naturally produced and isolated from various sources, including plants, animals and microorganisms, in which they constitute part of host defense systems. Many naturally occurring compounds, such as nisin, plant essential oils, and natamycin, have been widely studied and are reported to be effective in their potential role as antimicrobial agents against spoilage and pathogenic microorganisms. Although some of these natural antimicrobials are commercially available and applied in food processing, their efficacy, consumer acceptance and regulation are not well defined. This manuscript reviews natural antimicrobial compounds with reference to their applications in food when applied individually or in combination with other hurdles. It also reviews the mechanism of action of selected natural antimicrobials, factors affecting their antimicrobial activities, and future prospects for use of natural antimicrobials in the food industry.

  18. Man's nature: innate determinants of response to natural environments

    Treesearch

    B. L. Driver; Peter Greene

    1977-01-01

    Man's sensory mechanisms evolved by natural selection in natural settings and humans survived as a species not so much by the "club in the hand" but by the "plan in the head." That plan or ability enabled man to remember, interpret, and predict environmental events. Humans have an innate capacity (but not necessarily a developed ability) to...

  19. US crude oil, natural gas, and natural gas liquids reserves, 1992 annual report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1993-10-18

    This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1992, as well as production volumes for the United States, and selected States and State subdivisions for the year 1992. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), its two major components (nonassociated and associated-dissolved gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, two components of natural gas liquids, lease condensate and natural gas plant liquids, have their reservesmore » and production data presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1992 is provided.« less

  20. Healing relationships with nature.

    PubMed

    Burkhardt, M A

    2000-02-01

    Our health is intimately connected to the health of our environment. The contemporary world view which sees a radical distinction between humans as subjects and world as object can obscure our recognition of how much we rely on nature for health and survival. Indigenous traditions and contemporary scholars remind us that we live in a universe in which all things are connected, and in which nature continues to offer its gifts in co-creative partnership for the health and wellbeing of all. Living in awareness of our relationship with nature enables us to open more to the experience of nature's nurturing. Many complementary therapies derive from ancient practices that involve nature in healing partnership. As nurses and midwives we must learn to expand our boundaries to encompass the many ways that nature partners with us for healing.

  1. Middle Years Students' Experiences in Nature: A Case Study on Nature-Play

    ERIC Educational Resources Information Center

    Francis, Marj; Paige, Kathy; Lloyd, David

    2013-01-01

    Increasingly, children today are becoming disconnected from the natural environments resulting in a diminished sense of self, place and community. In an attempt to find out their perceptions, attitudes and values about the natural world, twenty-five Year 6 and 7 students from a northern Adelaide primary school participated in a nature-play case…

  2. U.S. crude oil, natural gas, and natural gas liquids reserves 1997 annual report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wood, John H.; Grape, Steven G.; Green, Rhonda S.

    1998-12-01

    This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1997, as well as production volumes for the US and selected States and State subdivisions for the year 1997. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), nonassociated gas and associated-dissolved gas (which are the two major types of wet natural gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, reserve estimates for two types of natural gas liquids, leasemore » condensate and natural gas plant liquids, are presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1997 is provided. 21 figs., 16 tabs.« less

  3. Enhance Nature Exploration with Technology

    ERIC Educational Resources Information Center

    Holloway, Patricia; Mahan, Carol

    2012-01-01

    Kids and nature seem like a natural combination, but what was natural a generation ago is different today. Children are spending less time outdoors but continue to need nature for their physical, emotional, and mental development. This fact has led author Richard Louv to suggest that today's children are suffering from "nature-deficit disorder"…

  4. At the foot of the shrew: Manus morphology distinguishes closely-related Cryptotis goodwini and Cryptotis griseoventris (Mammalia: Soricidae) in Central America

    USGS Publications Warehouse

    Woodman, Neal; Stephens, Ryan B.

    2010-01-01

    Small-eared shrews (Mammalia, Soricidae) of the New World genus Cryptotis are distributed from eastern North America to the northern Andes of South America. One well-defined clade in this genus is the Central American Cryptotis mexicana group, whose members are set off from other species in the genus by their variably broader fore feet and more elongate and broadened fore claws. Two species in the C. mexicana group, Cryptotis goodwini Jackson and Cryptotis griseoventris Jackson, inhabit highlands in Guatemala and southern Mexico and are presumed to be sister species whose primary distinguishing feature is the larger body size of C. goodwini. To better characterize these species and confirm the identification of recently-collected specimens, we obtained digital X-ray images of the manus from large series of dried skins of both species. Measurements of the metacarpals and phalanges successfully separated most specimens of C. goodwini and C. griseoventris. These measurements also show that the fore feet of C. griseoventris from Chiapas, Mexico, are morphologically distinct from those of members of the species inhabiting Guatemala. Univariate, bivariate, and multivariate analyses indicate that fore foot characters are more conservative within species of the C. mexicana group than are cranio-mandibular characters. Patterns of evolution of fore foot characters that superficially appear to be linear gradations are actually more complex, illustrating individual evolutionary trajectories.

  5. Demonstrating Natural Selection

    ERIC Educational Resources Information Center

    Hinds, David S.; Amundson, John C.

    1975-01-01

    Describes laboratory exercises with chickens selecting their food from dyed and natural corn kernels as a method of demonstrating natural selection. The procedure is based on the fact that organisms that blend into their surroundings escape predation. (BR)

  6. Natural Gas Exports from Iran

    EIA Publications

    2012-01-01

    This assessment of the natural gas sector in Iran, with a focus on Iran’s natural gas exports, was prepared pursuant to section 505 (a) of the Iran Threat Reduction and Syria Human Rights Act of 2012 (Public Law No: 112-158). As requested, it includes: (1) an assessment of exports of natural gas from Iran; (2) an identification of the countries that purchase the most natural gas from Iran; (3) an assessment of alternative supplies of natural gas available to those countries; (4) an assessment of the impact a reduction in exports of natural gas from Iran would have on global natural gas supplies and the price of natural gas, especially in countries identified under number (2); and (5) such other information as the Administrator considers appropriate.

  7. Natural Gas Monthly

    EIA Publications

    2017-01-01

    Highlights activities, events, and analyses associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer related activities and underground storage data are also reported.

  8. GHGRP Natural Gas and Natural Gas Liquids Suppliers Sector Industrial Profile

    EPA Pesticide Factsheets

    EPA's Greenhouse Gas Reporting Program periodically produces detailed profiles of the various industries that report under the program. The profiles available for download below contain detailed analyses for the Natural Gas and Natural Gas Suppliers indust

  9. Nature in the City.

    ERIC Educational Resources Information Center

    Ferbert, Mary Lou

    1981-01-01

    Describes a science program developed by the Cleveland Museum of Natural History, "Nature in the City," in which students and teachers learn together about the natural community surrounding their school. Includes program's rationale, list of "adventures," and methods. Discusses strategies of Sherlock Holmes'"adventure" focusing on animal tracks…

  10. A natural compromise: a moderate solution to the GMO & "natural" labeling disputes.

    PubMed

    Amaru, Stephanie

    2014-01-01

    In the United States, genetically modified (GM) foods are labeled no differently from their natural counterparts, leaving consumers with no mechanism for deciphering genetically modified food content. The Food and Drug Administration (FDA) has not formally defined the term "natural," which is frequently used on food labels despite consumer confusion as to what it means. The FDA should initiate a notice and comment rulemaking addressing the narrow issue of whether use of the word "natural" should be permitted oil GM food labels. Prohibition of the use of"natural" on genetically modified foods would mitigate consumer deception regarding genetically modified food content without significantly disadvantaging genetically modified food producers.

  11. PLANNING A NATURE CENTER.

    ERIC Educational Resources Information Center

    ASHBAUGH, BYRON L.

    THIS BULLETIN IS PRODUCED BY THE NATURE CENTERS DIVISION, NATIONAL AUDUBON SOCIETY TO PROVIDE PROFESSIONAL GUIDANCE AND TECHNICAL KNOW-HOW IN THE DEVELOPMENT OF COMMUNITY NATURE AND CONSERVATION CENTERS. THE TOPICS COVERED ARE--(1) PURPOSE AND VALUE OF A NATURE AND CONSERVATION CENTER, (2) INITIAL CONSIDERATIONS SUCH AS COMMUNITY READINESS, LAND…

  12. Nanoparticles in natural systems II: The natural oxide fraction at interaction with natural organic matter and phosphate

    NASA Astrophysics Data System (ADS)

    Hiemstra, Tjisse; Antelo, Juan; van Rotterdam, A. M. D.(Debby); van Riemsdijk, Willem H.

    2010-01-01

    Information on the particle size and reactive surface area of natural samples and its interaction with natural organic matter (NOM) is essential for the understanding bioavailability, toxicity, and transport of elements in the natural environment. In part I of this series ( Hiemstra et al., 2010), a method is presented that allows the determination of the effective reactive surface area ( A, m 2/g soil) of the oxide particles of natural samples which uses a native probe ion (phosphate) and a model oxide (goethite) as proxy. In soils, the natural oxide particles are generally embedded in a matrix of natural organic matter (NOM) and this will affect the ion binding properties of the oxide fraction. A remarkably high variation in the natural phosphate loading of the oxide surfaces ( Γ, μmol/m 2) is observed in our soils and the present paper shows that it is due to surface complexation of NOM, acting as a competitor via site competition and electrostatic interaction. The competitive interaction of NOM can be described with the charge distribution (CD) model by defining a ≡NOM surface species. The interfacial charge distribution of this ≡NOM surface species can be rationalized based on calculations done with an evolved surface complexation model, known as the ligand and charge distribution (LCD) model. An adequate choice is the presence of a charge of -1 v.u. at the 1-plane and -0.5 v.u. at the 2-plane of the electrical double layer used (Extended Stern layer model). The effective interfacial NOM adsorption can be quantified by comparing the experimental phosphate concentration, measured under standardized field conditions (e.g. 0.01 M CaCl 2), with a prediction that uses the experimentally derived surface area ( A) and the reversibly bound phosphate loading ( Γ, μmol/m 2) of the sample (part I) as input in the CD model. Ignoring the competitive action of adsorbed NOM leads to a severe under-prediction of the phosphate concentration by a factor ˜10 to 1000

  13. Evaluation of natural sounds in urban greenery: potential impact for urban nature preservation

    PubMed Central

    Knez, I.; Ode Sang, Å.; Gunnarsson, B.

    2017-01-01

    Most humans now live in cities and their main experience of nature is through urban greenery. An increasing number of studies show the importance of urban green spaces for well-being, although most of them are based on visual perception. A questionnaire examining people's evaluations of natural sounds was answered by 1326 individuals living near one of six urban green areas of varying naturalness in the city of Gothenburg, Sweden. Women and the elderly reported greater calmness when hearing bird song and rustling leaves (and placed a higher importance on the richness of bird species) than did men, younger and middle-aged individuals. Independent of age and gender, urban woodlands (high naturalness) had higher evaluations than parks (low naturalness). Our results suggest that to increase positive experiences of urban green areas, demographic variables of gender and age should be taken into account, and settings that mimic nature should be prioritized in planning. PMID:28386456

  14. Naturalness and Animal Welfare

    PubMed Central

    Yeates, James

    2018-01-01

    Simple Summary Many people feel that we should ensure that animals have natural lives and can perform natural behaviours. However, it is unclear what exactly we mean by ‘natural’ and how we can assess it scientifically. We might use naturalness to highlight possible suffering that needs looking into, as a rule of thumb about what is good for animals, and to establish a threshold for what is acceptable or unacceptable in how we affect animals. We can assess animals’ naturalness in terms of how similar they are to their closest wild counterparts, both in scientific assessments and in decisions about how we care for animals. Abstract Naturalness is considered important for animals, and is one criterion for assessing how we care for them. However, it is a vague and ambiguous term, which needs definition and assessments suitable for scientific and ethical questions. This paper makes a start on that aim. This paper differentiates the term from other related concepts, such as species-typical behaviour and wellbeing. It identifies contingent ways in which naturalness might be used, as: (i) prompts for further welfare assessment; (ii) a plausible hypothesis for what safeguards wellbeing; (iii) a threshold for what is acceptable; (iv) constraints on what improvements are unacceptable; and (v) demarcating what is not morally wrong, because of a lack of human agency. It then suggests an approach to evaluating animals’ behaviour that is quantitative, is based on reality, and which assesses naturalness by degrees. It proposes classing unaffected wild populations as natural by definition. Where animals might have been affected by humans, they should be compared to the closest population(s) of unaffected animals. This approach could allow us both to assess naturalness scientifically, and to make practical decisions about the behaviour of domestic animals. PMID:29621140

  15. Adaptive release of natural enemies in a pest-natural enemy system with pesticide resistance.

    PubMed

    Liang, Juhua; Tang, Sanyi; Cheke, Robert A; Wu, Jianhong

    2013-11-01

    Integrated pest management options such as combining chemical and biological control are optimal for combating pesticide resistance, but pose questions if a pest is to be controlled to extinction. These questions include (i) what is the relationship between the evolution of pesticide resistance and the number of natural enemies released? (ii) How does the cumulative number of natural enemies dying affect the number of natural enemies to be released? To address these questions, we developed two novel pest-natural enemy interaction models incorporating the evolution of pesticide resistance. We investigated the number of natural enemies to be released when threshold conditions for the extinction of the pest population in two different control tactics are reached. Our results show that the number of natural enemies to be released to ensure pest eradication in the presence of increasing pesticide resistance can be determined analytically and depends on the cumulative number of dead natural enemies before the next scheduled release time.

  16. Natural Hazards, Second Edition

    NASA Astrophysics Data System (ADS)

    Rouhban, Badaoui

    Natural disaster loss is on the rise, and the vulnerability of the human and physical environment to the violent forces of nature is increasing. In many parts of the world, disasters caused by natural hazards such as earthquakes, floods, landslides, drought, wildfires, intense windstorms, tsunami, and volcanic eruptions have caused the loss of human lives, injury, homelessness, and the destruction of economic and social infrastructure. Over the last few years, there has been an increase in the occurrence, severity, and intensity of disasters, culminating with the devastating tsunami of 26 December 2004 in South East Asia.Natural hazards are often unexpected or uncontrollable natural events of varying magnitude. Understanding their mechanisms and assessing their distribution in time and space are necessary for refining risk mitigation measures. This second edition of Natural Hazards, (following a first edition published in 1991 by Cambridge University Press), written by Edward Bryant, associate dean of science at Wollongong University, Australia, grapples with this crucial issue, aspects of hazard prediction, and other issues. The book presents a comprehensive analysis of different categories of hazards of climatic and geological origin.

  17. Male-biased predation of a cave fish by a giant water bug.

    PubMed

    Tobler, Michael; Franssen, Courtney M; Plath, Martin

    2008-08-01

    Male-biased predation has been described from several epigean species, and in many cases, intrinsic differences between the sexes (such as male ornaments) have been suggested as an explanation. Here we report on male-biased predation of a cave fish (Poecilia mexicana) by an aquatic insect (Belostoma sp.) in a Mexican sulfur cave. P. mexicana use aquatic surface respiration (ASR) to survive in their sulfidic, hypoxic habitat. We found that males typically exhibit more ASR activity than females, which leads to increased exposure to the sit-and-wait predator that catches fish near the water surface. Our finding is novel, because male vulnerability to predation is not directly related to male traits involved in courtship, but rather due to other sexual differences in behavior and ultimately, oxygen demands.

  18. The "History" of Victorian Scientific Naturalism: Huxley, Spencer and the "End" of natural history.

    PubMed

    Lightman, Bernard

    2016-08-01

    As part of their defence of evolutionary theory, T. H. Huxley and Herbert Spencer argued that natural history was no longer a legitimate scientific discipline. They outlined a secularized concept of life from biology to argue for the validity of naturalism. Despite their support for naturalism, they offered two different responses to the decline of natural history. Whereas Huxley emphasized the creation of a biological discipline, and all that that entailed, Spencer was more concerned with constructing an entire intellectual system based on the idea of evolution. In effect, Spencer wanted to create a new scientific worldview based on evolutionary theory. This had consequences for their understanding of human history, especially of how science had evolved through the ages. It affected their conceptions of human agency, contingency, and directionality in history. Examining Huxley's and Spencer's responses to the "end" of natural history reveals some of the deep divisions within scientific naturalism and the inherent problems of naturalism in general. Whereas Huxley chose to separate the natural and the historical, Spencer opted to fuse them into a single system. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  19. Lesson "Balance in Nature

    NASA Astrophysics Data System (ADS)

    Chapanova, V.

    2012-04-01

    Lesson "Balance in Nature" This simulation game-lesson (Balance in Nature) gives an opportunity for the students to show creativity, work independently, and to create models and ideas. It creates future-oriented thought connected to their experience, allowing them to propose solutions for global problems and personal responsibility for their activities. The class is divided in two teams. Each team chooses questions. 1. Question: Pollution in the environment. 2. Question: Care for nature and climate. The teams work on the chosen tasks. They make drafts, notes and formulate their solutions on small pieces of paper, explaining the impact on nature and society. They express their points of view using many different opinions. This generates alternative thoughts and results in creative solutions. With the new knowledge and positive behaviour defined, everybody realizes that they can do something positive towards nature and climate problems and the importance of individuals for solving global problems is evident. Our main goal is to recover the ecological balance, and everybody explains his or her own well-grounded opinions. In this work process the students obtain knowledge, skills and more responsible behaviour. This process, based on his or her own experience, dialogue and teamwork, helps the participant's self-development. Making the model "human↔ nature" expresses how human activities impact the natural Earth and how these impacts in turn affect society. Taking personal responsibility, we can reduce global warming and help the Earth. By helping nature we help ourselves. Teacher: Veselina Boycheva-Chapanova " Saint Patriarch Evtimii" Scholl Str. "Ivan Vazov"-19 Plovdiv Bulgaria

  20. NATURALIZATION OF U.S. IMMIGRANTS

    PubMed Central

    Woodrow-Lafield, Karen A.; Xu, Xiaohe; Kersen, Thomas; Poch, Bunnak

    2008-01-01

    The saga of U.S. immigrant naturalization is merely sketched for about 25 million immigrants entered in three decades of renewed immigration. This study documents naturalization outcomes for immigrants from ten major countries of origin, using administrative records on immigrants and naturalizations. Following the 1978-1987 admission cohorts for the first decade or more of permanent residence, this study finds significant covariate effects on the timing of naturalization by origin, mode of entry, and immigrant visa class, net other influences of demographic and background characteristics. Immigrants from the Philippines, Vietnam, and China, naturalized more quickly than immigrants from India, Korea, Cuba, Colombia, Jamaica, the Dominican Republic, and Mexico. Those who adjusted from statuses as nonimmigrants, refugees, or asylees became naturalized citizens more quickly. Those immigrants with employment-sponsorship naturalized faster than family-sponsored immigrants. Spouses of citizens, spouses of permanent residents, spouses of siblings of citizens, and spouses of sons and daughters of citizens naturalized faster than some other immigrants. Gender was not significant in the multivariate analysis but further research will more fully explore sex-specific variation in the timing of naturalization given likely variation in women’s representation by origin and admission categories. PMID:19122767

  1. Biology, host instar suitability and susceptibility, and interspecific competition of three introduced parasitoids of Paracoccus marginatus (Hemiptera: Pseudococcidae)

    USDA-ARS?s Scientific Manuscript database

    Biology, host stage suitability and susceptibility, and interspecific competition of three previously introduced parasitoids (Acerophagus papayae, Anagyrus loecki, and Pseudleptomastix mexicana) (Hymenoptera: Encyrtidae) of Paracoccus marginatus were studied in the laboratory. Compared to P. mexica...

  2. 75 FR 13524 - Northern Natural Gas Company, Southern Natural Gas Company, Florida Gas Transmission Company, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-22

    ... Natural Gas Company, Southern Natural Gas Company, Florida Gas Transmission Company, LLC, Transcontinental... notice that on March 5, 2010, Northern Natural Gas Company (Northern Natural), 1111 South 103rd Street, Omaha, Nebraska 68124- 1000, filed on behalf of itself and other owners, Southern Natural Gas Company...

  3. Colour agnosia impairs the recognition of natural but not of non-natural scenes.

    PubMed

    Nijboer, Tanja C W; Van Der Smagt, Maarten J; Van Zandvoort, Martine J E; De Haan, Edward H F

    2007-03-01

    Scene recognition can be enhanced by appropriate colour information, yet the level of visual processing at which colour exerts its effects is still unclear. It has been suggested that colour supports low-level sensory processing, while others have claimed that colour information aids semantic categorization and recognition of objects and scenes. We investigated the effect of colour on scene recognition in a case of colour agnosia, M.A.H. In a scene identification task, participants had to name images of natural or non-natural scenes in six different formats. Irrespective of scene format, M.A.H. was much slower on the natural than on the non-natural scenes. As expected, neither M.A.H. nor control participants showed any difference in performance for the non-natural scenes. However, for the natural scenes, appropriate colour facilitated scene recognition in control participants (i.e., shorter reaction times), whereas M.A.H.'s performance did not differ across formats. Our data thus support the hypothesis that the effect of colour occurs at the level of learned associations.

  4. The Ecology of Hope: Natural Guides to Building a Children and Nature Movement

    ERIC Educational Resources Information Center

    Charles, Cheryl

    2009-01-01

    Cheryl Charles, Ph.D gave the 2009 Paul F-Brandwein Lecture. The lecture addresses the impact of children's disconnect from the natural world in their everyday lives. Co-founder of the Children & Nature Network (C&NN) with Richard Louv, author of "Last Child in the Woods: Saving Our Children from Nature-Deficit Disorder" (2005/2008), the author…

  5. Natural Resources Bibliography.

    ERIC Educational Resources Information Center

    Hoadley, Irene Braden

    This bibliography presents a modern definition of the conceptual framework from which to view natural resources, and affords access to information which examines resources from the social scientists point of view. It presents five broad divisions of activity or variables which include (1) Natural and Human Resources, (2) Epistomological and…

  6. Natural gas monthly, June 1996

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1996-06-24

    The natural gas monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The feature article for this month is Natural Gas Industry Restructuring and EIA Data Collection.

  7. Modeling Natural Selection

    ERIC Educational Resources Information Center

    Bogiages, Christopher A.; Lotter, Christine

    2011-01-01

    In their research, scientists generate, test, and modify scientific models. These models can be shared with others and demonstrate a scientist's understanding of how the natural world works. Similarly, students can generate and modify models to gain a better understanding of the content, process, and nature of science (Kenyon, Schwarz, and Hug…

  8. Natural gas monthly, April 1997

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1997-04-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are present3ed each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The feature article is entitled ``Natural gas pipeline and system expansions.`` 6 figs., 27 tabs.

  9. "Diseases and natural kinds".

    PubMed

    Sulmasy, Daniel P

    2005-01-01

    David Thomasma called for the development of a medical ethics based squarely on the philosophy of medicine. He recognized, however, that widespread anti-essentialism presented a significant barrier to such an approach. The aim of this article is to introduce a theory that challenges these anti-essentialist objections. The notion of natural kinds presents a modest form of essentialism that can serve as the basis for a foundationalist philosophy of medicine. The notion of a natural kind is neither static nor reductionistic. Disease can be understood as making necessary reference to living natural kinds without invoking the claim that diseases themselves are natural kinds. The idea that natural kinds have a natural disposition to flourish as the kinds of things that they are provides a telos to which to tether the notion of disease - an objective telos that is broader than mere survival and narrower than subjective choice. It is argued that while nosology is descriptive and may have therapeutic implications, disease classification is fundamentally explanatory. Sickness and illness, while referring to the same state of affairs, can be distinguished from disease phenomenologically. Scientific and diagnostic fallibility in making judgments about diseases do not diminish the objectivity of this notion of disease. Diseases are things, not kinds. Injury is a concept parallel to disease that also makes necessary reference to living natural kinds. These ideas provide a new possibility for the development of a philosophy of medicine with implications for medical ethics.

  10. The Unnatural Nature of Nature and Nurture: Questioning the Romantic Heritage

    ERIC Educational Resources Information Center

    Stables, Andrew

    2009-01-01

    From a cultural-historical perspective, nature and nurture (and thus education) are contested concepts. The paper focuses on the nature/nurture debate in the work of William Shakespeare (influenced by Montaigne) and in the Romantic tradition (evidenced by Rousseau and Wordsworth), and argues that while our Romantic inheritance (still highly…

  11. Kant on the history of nature: the ambiguous heritage of the critical philosophy for natural history.

    PubMed

    Sloan, Phillip R

    2006-12-01

    This paper seeks to show Kant's importance for the formal distinction between descriptive natural history and a developmental history of nature that entered natural history discussions in the late eighteenth century. It is argued that he developed this distinction initially upon Buffon's distinctions of 'abstract' and 'physical' truths, and applied these initially in his distinction of 'varieties' from 'races' in anthropology. In the 1770s, Kant appears to have given theoretical preference to the 'history' of nature [Naturgeschichte] over 'description' of nature [Naturbeschreibung]. Following Kant's confrontations with Johann Herder and Georg Forster in the late 1780s, Kant weakened the epistemic status of the 'history of nature' and gave theoretical preference to 'description of nature'. As a result, Kant's successors, such as Goethe, could draw from Kant either a justification for a developmental history of nature, or, as this paper argues, a warrant from the critical philosophy for denying the validity of the developmental history of nature as anything more than a 'regulative' idea of reason.

  12. Natural and technologic hazardous material releases during and after natural disasters: a review.

    PubMed

    Young, Stacy; Balluz, Lina; Malilay, Josephine

    2004-04-25

    Natural disasters may be powerful and prominent mechanisms of direct and indirect hazardous material (hazmat) releases. Hazardous materials that are released as the result of a technologic malfunction precipitated by a natural event are referred to as natural-technologic or na-tech events. Na-tech events pose unique environmental and human hazards. Disaster-associated hazardous material releases are of concern, given increases in population density and accelerating industrial development in areas subject to natural disasters. These trends increase the probability of catastrophic future disasters and the potential for mass human exposure to hazardous materials released during disasters. This systematic review summarizes direct and indirect disaster-associated releases, as well as environmental contamination and adverse human health effects that have resulted from natural disaster-related hazmat incidents. Thorough examination of historic disaster-related hazmat releases can be used to identify future threats and improve mitigation and prevention efforts.

  13. The Case for Natural History

    NASA Astrophysics Data System (ADS)

    King, Heather; Achiam, Marianne

    2017-03-01

    Fundamental knowledge of natural history is lacking in many western societies, as demonstrated by its absence in school science curricula. And yet, to meet local and global challenges such as environmental degradation, biodiversity loss and climate change, we need to better understand the living and non-living parts of the natural world. Many have argued passionately for an increased understanding of natural history; others have developed successful pedagogical programmes for applying knowledge of natural history in environmental initiatives. In joining wider calls, we choose here to focus on the educational value afforded by understanding the epistemological bases of natural history and its particular forms of reasoning. We also briefly discuss the ways in which an education in natural history provides the foundation for environmental and social justice efforts that directly affect the lives of young people and their communities. We end by highlighting the ease by which natural history may be incorporated in learning opportunities both in and outside of the classroom.

  14. An Overview of Some Natural Products with Two A-Level Science Club Natural Products Experiments

    ERIC Educational Resources Information Center

    Sosabowski, Michael Hal; Olivier, George W. J.; Jawad, Hala; Maatta, Sieja

    2017-01-01

    Natural products are ubiquitous in nature but do not form a large proportion of the A-level syllabuses in the UK. In this article we briefly discuss a small selection of natural products, focusing on alcohols, aldehydes and ketones, and alkaloids. We then outline two natural product experiments that are suitable for A-level chemistry clubs or…

  15. Nature's Advice Book

    ERIC Educational Resources Information Center

    Mahlin, Kathryn; Robertson, Amy

    2005-01-01

    What do can people learn from the world around them? Can a tree really teach something about life? Many times teachers provide students with facts about nature but fail to consider what one can learn from the natural world around them. After many months of exploring various ecosystems such as the prairie, rain forest, and desert, one of the…

  16. Nature Foil Reliefs

    ERIC Educational Resources Information Center

    Lane, Shaw J.

    2012-01-01

    Nature has always been a source of inspiration for artists across the centuries. Artists such as Leonardo da Vinci, Georgia O'Keeffe, Ansel Adams, and Andy Goldsworthy all drew inspiration for their work from nature. Seeds come from the dried pods, which when planted and cared for, bear fruit. In this article, the author describes how her…

  17. Nature as a Guide: Using Nature in Counseling, Therapy, and Education.

    ERIC Educational Resources Information Center

    Nebbe, Linda Lloyd

    This book contains practical activities for teachers, counselors, and other helping professionals utilizing elements in nature. The premise for the utilization of nature therapy is that if people develop an awareness and reverence for life, they will also develop self-understanding and self-respect. The first four chapters provide a rationale for…

  18. Developmental time, longevity, and lifetime fertility of three introduced parasitoids of the mealybug Paracoccus marginatus (Hemiptera: Pseudoccidae)

    USDA-ARS?s Scientific Manuscript database

    Developmental time, longevity, and lifetime fertility of three previously introduced parasitoids (Acerophagus papayae Noyes and Schauff, Anagyrus loecki Noyes and Menezes, and Pseudleptomastix mexicana Noyes and Schauff) (Hymenoptera: Encyrtidae) of the mealybug Paracoccus marginatus Williams and Gr...

  19. Leluthia astigma (Ashmead) (Hymenoptera: Braconidae: Doryctinae) as a parasitoid of Agrilus planipennis Fairmaire (Coleoptera: Buprestidae: Agrilinae), with an assessment of host associations for nearctic species of Leluthia Cameron.

    Treesearch

    Robert R. Kula; Kathleen S. Knight; Joanne Rebbeck; Leah S. Bauer; David L. Cappaert; Kamal J.K. Gandhi

    2010-01-01

    Published host associations are assessed for Leluthia astigma (Ashmead), Leluthia floridensis Marsh, and Leluthia mexicana Cameron, the three known species of Leluthia Cameron in the Nearctic Region. Leluthia astigma is reported as a parasitoid of Agrilus planipennis...

  20. Exposure to natural environments, and photographs of natural environments, promotes more positive body image.

    PubMed

    Swami, Viren; Barron, David; Furnham, Adrian

    2018-03-01

    Five studies were conducted to understand the impact of nature exposure on body image. In three studies using different designs and outcome measures, British university students were exposed to photographs of natural or built environments. Results indicated that exposure to images of natural, but not built, environments resulted in improved state body image. In Study 4, British community participants went on a walk in a natural or built environment, with results indicating that the walk in a natural environment resulted in significantly higher state body appreciation, whereas the walk in a built environment resulted in significantly lower scores. In Study 5, British participants were recruited as they were entering a designed green space on their own volition. Results indicated that spending time in the green space led to improved state body appreciation. These results indicate that exposure to isomorphic or in-situ natural environments has positive effects on state body image. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. The Science of Middle Nature

    NASA Astrophysics Data System (ADS)

    Pataki, D. E.; Pincetl, S.

    2012-12-01

    In the field of biogeochemistry, urbanization is often considered as an "alteration" or "disturbance" to the earth's surface and its natural processes. This view is an outcome of the view of nature inherent in earth system science and ecology, in which nature is defined as separate from humans and society. However, other disciplines are based in alternative views of nature in which humans are more integral components of the landscape. Urban planning, landscape architecture, agriculture, and horticulture, for example, more fully integrate the role of landscape design and management in the functioning of human-dominated ecosystems. We suggest that the field of urban biogeochemistry has been somewhat limited by the predominant, disturbance-based view of the role of nature in cities, and that more deeply evaluating and broadening the concept of nature inherent in studies of urban processes can enhance our understanding of the role of urbanization in the earth system. A particularly useful concept is the "middle nature" proposed by Cosgrove (1993), which serves a purpose of "actively transforming nature into culture." It is this view of urban landscapes as middle nature, or transformation of urban space into human-dominated nature with a purpose, that is lacking from the current scientific discourse about the role of biogeochemistry in urban ecosystem services. A scientific evaluation of middle nature implies studying the performance of urban designs to meet intended cultural and environmental goals, including beauty, social equity, governance, and social capital as well as environmental quality. We describe our work in evaluating the transformed urban landscapes of Los Angeles from multiple perspectives that focus on urban livability, equity, and beauty as well as the physical impacts of plants and soils on the environment. The outcomes of this process do not necessary meet the traditional demands of biophysical ecology such as utilizing native species, maximizing

  2. Natural Products and HIV/AIDS.

    PubMed

    Cary, Daniele C; Peterlin, B Matija

    2018-01-01

    The study of natural products in biomedical research is not a modern concept. Many of the most successful medical therapeutics are derived from natural products, including those studied in the field of HIV/AIDS. Biomedical research has a rich history of discovery based on screens of medicinal herbs and traditional medicine practices. Compounds derived from natural products, which repress HIV and those that activate latent HIV, have been reported. It is important to remember the tradition in medical research to derive therapies based on these natural products and to overcome the negative perception of natural products as an "alternative medicine."

  3. Natural gas monthly, August 1993

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1993-08-25

    The Natural Gas Monthly (NGM) is prepared in the Data Operations Branch of the Reserves and Natural Gas Division, Office of Oil and Gas, Energy Information Administration (EIA), US Department of Energy (DOE). The NGM highhghts activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

  4. Natural gas monthly, July 1994

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1994-07-20

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

  5. Natural gas monthly, September 1995

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1995-09-27

    The (NGM) Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

  6. Natural Gas Imports and Exports

    EIA Publications

    2017-01-01

    Natural gas net imports set a record low of 685 billion cubic feet (Bcf) in 2016, continuing a decline for the 10th consecutive year. U.S. exports were more than three times larger than the level 10 years ago as a result of significant infrastructure improvements to natural gas pipelines and liquefied natural gas facilities. These changes are discussed in the U.S. Natural Gas Imports & Exports 2016 report.

  7. Sebastian Kneipp and the Natural Cure Movement of Germany: Between Naturalism and Modern Medicine.

    PubMed

    Ko, Youkyung

    2016-12-01

    This study discusses the historical significance of the Natural Cure Movement of Germany, centering on the Kneipp Cure, a form of hydrotherapy practiced by Father Sebastian Kneipp (1821-1897). The Kneipp Cure rested on five main tenets: hydrotherapy, exercise, nutrition, herbalism, and the balance of mind and body. This study illuminates the reception of the Kneipp Cure in the context of the trilateral relationship among the Kneipp Cure, the Natural Cure Movement in general, and modern medicine. The Natural Cure Movement was ideologically based on naturalism, criticizing industrialization and urbanization. There existed various theories and methods in it, yet they shared holism and vitalism as common factors. The Natural Cure Movement of Germany began in the early 19th century. During the late 19th century and the early 20th century, it became merged in the Lebensreformbewegung (life reform movement) which campaigned for temperance, anti-tobacco, and anti-vaccination. The core of the Natural Cure Movement was to advocate the world view that nature should be respected and to recognize the natural healing powers of sunlight, air, water, etc. Among varied natural therapies, hydrotherapy spread out through the activities of some medical doctors and amateur healers such as Johann Siegmund Hahn and Vincenz Prie βnitz. Later, the supporters of hydrotherapy gathered together under the German Society of Naturopathy. Sebastian Kneipp, one of the forefathers of hydrotherapy, is distinguished from other proponents of natural therapies in two aspects. First, he did not refuse to employ vaccination and medication. Second, he sought to be recognized by the medical world through cooperating with medical doctors who supported his treatment. As a result, the Kneipp cure was able to be gradually accepted into the medical world despite the "quackery" controversy between modern medicine and the Natural Cure Movement. Nowadays, the name of Sebastian Kneipp remains deeply engraved on

  8. Education in the imbalance of Nature

    NASA Astrophysics Data System (ADS)

    Shlafman, L. M.; Kontar, V. A.

    2013-12-01

    There are two concepts understanding of the real Nature: balanced and imbalanced. The traditional balanced concept understanding of Nature was originated in prehistoric times to calm the frightened souls of prehistoric man and manage groups of people. The balanced concept presupposes that Nature is isotropic, balanced, etc. The balanced concept of understanding of Nature gradually has moved to science and technology. The balanced concept of understanding of Nature is dominating from the prehistoric time up to today. But always parallel and opposite was exists the concept imbalanced understanding of Nature, which presupposes that Nature is anisotropy, imbalanced, etc. The balanced concept is much simpler than Imbalanced. The balanced concept has given mankind a lot of rough description of Nature which helped to solve a lot of practical problems but with sufficient accuracy, i.e. approximately, but not with an absolute precision. While people were few, and a lot of resources, person could take from Nature only what Nature gave willingly. During this period, people feared and respected Nature and Nature was able easily compensate the activity of people. The high accuracy of the description of Nature was not needed when resources were plentiful and people were few. But now the situation is completely different. The population has become a very large and growing. Traditional resources are almost run out and the lack of resources escalates. People are not afraid of Nature and bravely try to take by force what Nature does not give voluntarily. People invaded into imbalance Nature, and Nature can no longer compensate activity of people. The era of global change is started, including those that man provokes. In the conditions of global changes is insufficiently of the approximate solutions of the traditional balanced concept. The balanced concept is exhausted, and increasingly misleads people. The balanced concept cannot solve the problems that arise in the global change

  9. Why are natural disasters not 'natural' for victims?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kumagai, Yoshitaka; Edwards, John; Carroll, Matthew S.

    Some type of formal or informal social assessment is often carried out in the wake of natural disasters. One often-observed phenomenon in such situations is that disaster victims and their sympathizers tend to focus on those elements of disasters that might have been avoided or mitigated by human intervention and thus assign 'undue' levels of responsibility to human agents. Often the responsibility or blame is directed at the very government agencies charged with helping people cope with and recover from the event. This phenomenon presents particular challenges for those trying to understand the social impacts of such events because ofmore » the reflexive nature of such analysis. Often the social analyst or even the government agency manager must sort through such perceptions and behavior and (at least implicitly) make judgments about which assignments of responsibility may have some validity and which are largely the result of the psychology of the disaster itself. This article presents a conceptual framework derived largely from social psychology to help develop a better understand such perceptions and behavior. While no 'magic bullet' formula for evaluating the validity of disaster victims' claims is presented, the conceptual framework is presented as a starting point for understanding this particular aspect of the psychology of natural disasters.« less

  10. Formations Near the Libration Points: Design Strategies Using Natural and Non-Natural Arcs

    NASA Technical Reports Server (NTRS)

    Howell, K. C.; Marchand, B. G.

    2004-01-01

    Space based observatory and interferometry missions, such as Terrestrial Planet Finder (TPF), Stellar Imager, and MAXIM, have sparked great interest in multi-spacecraft formation flight in the vicinity of the Sun-Earth/Moon (SEM) libration points. The initial phase of this research considered the formation keeping problem from the perspective of continuous control as applied to non-natural formations. In the present study, closer inspection of the flow, corresponding to the stable and center manifolds near the reference orbit, reveals some interesting natural relative motions as well as some discrete control strategies for deployment. A hybrid control strategy is also employed that combines both the natural formation dynamics with non-natural motions via input feedback linearization techniques.

  11. Temporal Response of Foragers and Guards of Two Stingless Bee Species to Cephalic Compounds of the Robber Bee Lestrimelitta niitkib (Ayala) (Hymenoptera, Apidae).

    PubMed

    Campollo-Ovalle, A; Sánchez, D

    2018-03-16

    Lestrimelitta spp. are stingless bees that steal food and nesting materials from other highly social bees to survive. Though most of their victim species respond, either aggressively or submissively, to cephalic components of Lestrimelitta, little is known about if such response changes at some point during extended periods of exposure. Moreover, potential synergistic effects due to a mixture of victim's alarm/defense pheromones and Lestrimelitta mandibular pheromones, like in an actual attack, have not been examined so far. In this paper, we investigated the response of two species of non-robber stingless bees, Scaptotrigona mexicana (Guérin) and Tetragonisca angustula (Latreille), to (a) cephalic compounds from crushed heads of nestmates, (b) cephalic compounds of Lestrimelitta niitkib (Ayala), and (c) a mixture of (a) and (b). We found that even though T. angustula did not react to nestmates' crushed head, its response towards L. niitkib cephalic compounds was stronger and lasted longer than that of S. mexicana. Interestingly, the addition of crushed heads of the non-robber species to L. niitkib crushed heads caused no significant increase in the alarm response of both species. It may be that the absence of an alarm pheromone in T. angustula made this species more receptive to extraneous odors, which is not the case for S. mexicana; however, more species must be studied to elucidate any pattern regarding the absence/presence of alarm pheromones and the corresponding response to intruders' pheromones.

  12. Study of decolorisation of binary dye mixture by response surface methodology.

    PubMed

    Khamparia, Shraddha; Jaspal, Dipika

    2017-10-01

    Decolorisation of a complex mixture of two different classes of textile dyes Direct Red 81 (DR81) and Rhodamine B (RHB), simulating one of the most important condition in real textile effluent was investigated onto deoiled Argemone Mexicana seeds (A. Mexicana). The adsorption behaviour of DR81 and RHB dyes was simultaneously analyzed in the mixture using derivative spectrophotometric method. Central composite design (CCD) was employed for designing the experiments for this complex binary mixture where significance of important parameters and possible interactions were analyzed by response surface methodology (RSM). Maximum adsorption of DR81 and RHB by A. Mexicana was obtained at 53 °C after 63.33 min with 0.1 g of adsorbent and 8 × 10 -6  M DR81, 12 × 10 -6  M RHB with composite desirability of 0.99. The predicted values for percentage removal of dyes from the mixture were in good agreement with the experimental values with R 2 > 96% for both the dyes. CCD superimposed RSM confirmed that presence of different dyes in a solution created a competition for the adsorbent sites and hence interaction of dyes was one of the most important factor to be studied to simulate the real effluent. The adsorbent showed remarkable adsorption capacities for both the dyes in the mixture. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Enantiomeric Natural Products: Occurrence and Biogenesis**

    PubMed Central

    Finefield, Jennifer M.; Sherman, David H.; Kreitman, Martin; Williams, Robert M.

    2012-01-01

    In Nature, chiral natural products are usually produced in optically pure form; however, on occasion Nature is known to produce enantiomerically opposite metabolites. These enantiomeric natural products can arise in Nature from a single species, or from different genera and/or species. Extensive research has been carried out over the years in an attempt to understand the biogenesis of naturally occurring enantiomers, however, many fascinating puzzles and stereochemical anomalies still remain. PMID:22555867

  14. [Out of natural order: nature in discourses about cloning and stem cell research in Brazilian newspapers].

    PubMed

    Medeiros, Flavia Natércia da Silva

    2013-11-30

    Different conceptions of nature influence media coverage and public opinion about biotechnology. This study reports on a discourse analysis of the ideas about nature and what is natural expressed in Brazilian media coverage of cloning and stem cell research. In the discourse against this research, the biotechnologies in question are placed outside the natural order of things and deemed immoral. In the discourse of those who defend it, nature is portrayed as indifferent to the fate of humans or even cruel, or else a barrier to be overcome, while cloning and embryonic stem cells are naturalized and Dolly the sheep is anthropomorphized. The mythifying or transcendental representations of nature do not just influence public opinion, but also have ethical and political implications.

  15. Interspecific and intraspecific variation in Picea engelmannii and its congeneric cohorts: biosystematics, genecology, and climate change

    Treesearch

    Gerald E. Rehfeldt

    2004-01-01

    A series of common garden studies of 336 populations representing Picea engelmannii, P. pungens, P. glauca, P. mexicana, and P. chihuahuana provided as many as 13 growth and morphologic characters pertinent to biosystematics and genecology. Canonical discriminant analyses...

  16. Host instar susceptibility and selection and interspecific competition of three introduced parasitoids of the mealybug Paracoccus marginatus (Hemiptera: Pseudococccidae)

    USDA-ARS?s Scientific Manuscript database

    Acerophagus papayae, Anagyrus loecki, and Pseudleptomastix mexicana, three introduced parasitoids of Paracoccus marginatus were investigated for host stage susceptibility and sex ratio, host stage suitability, and interspecific competition. All three parasitoid species were able to develop and emer...

  17. Nature and Young Children: Encouraging Creative Play and Learning in Natural Environments. Second Edition

    ERIC Educational Resources Information Center

    Wilson, Ruth

    2012-01-01

    Now in its second edition, "Nature and Young Children" promotes the holistic development of children by connecting them with nature. It offers advice and guidance on how to set up indoor and outdoor nature play spaces as well as encouraging environmentally responsible attitudes, values and behaviour in your early childhood setting. Covering topics…

  18. Virginia Natural Heritage Program

    Science.gov Websites

    Heritage About Natural Heritage Overview, Mission Natural Heritage Inventory Community Ecology Program ) | Strategic Plan (PDF) | Executive Progress Report (PDF) | Code of Ethics (PDF) Your browser does not support

  19. Leishmania spp. epidemiology of canine leishmaniasis in the Yucatan Peninsula.

    PubMed

    López-Céspedes, A; Longoni, S S; Sauri-Arceo, C H; Sánchez-Moreno, M; Rodríguez-Vivas, R I; Escobedo-Ortegón, F J; Barrera-Pérez, M A; Bolio-González, M E; Marín, C

    2012-01-01

    Canine Leishmaniasis is widespread in various Mexican states, where different species of Leishmania have been isolated from dogs. In the present study, we describe the detection of L. braziliensis, L. infantum, and L. mexicana in serum of dogs from the states of Yucatan and Quintana Roo in the Yucatan Peninsula (Mexico). A total of 412 sera were analyzed by ELISA using the total extract of the parasite and the iron superoxide dismutase excreted by different trypanosomatids as antigens. We found the prevalence of L. braziliensis to be 7.52%, L. infantum to be 6.07%, and L. mexicana to be 20.63%, in the dog population studied. The results obtained with ELISA using iron superoxide dismutase as the antigen were confirmed by western blot analysis with its greater sensitivity, and the agreement between the two techniques was very high.

  20. Leishmania spp. Epidemiology of Canine Leishmaniasis in the Yucatan Peninsula

    PubMed Central

    López-Céspedes, A.; Longoni, S. S.; Sauri-Arceo, C. H.; Sánchez-Moreno, M.; Rodríguez-Vivas, R. I.; Escobedo-Ortegón, F. J.; Barrera-Pérez, M. A.; Bolio-González, M. E.; Marín, C.

    2012-01-01

    Canine Leishmaniasis is widespread in various Mexican states, where different species of Leishmania have been isolated from dogs. In the present study, we describe the detection of L. braziliensis, L. infantum, and L. mexicana in serum of dogs from the states of Yucatan and Quintana Roo in the Yucatan Peninsula (Mexico). A total of 412 sera were analyzed by ELISA using the total extract of the parasite and the iron superoxide dismutase excreted by different trypanosomatids as antigens. We found the prevalence of L. braziliensis to be 7.52%, L. infantum to be 6.07%, and L. mexicana to be 20.63%, in the dog population studied. The results obtained with ELISA using iron superoxide dismutase as the antigen were confirmed by western blot analysis with its greater sensitivity, and the agreement between the two techniques was very high. PMID:22927792

  1. Coastal habitat degradation and green sea turtle diets in Southeastern Brazil

    USGS Publications Warehouse

    Santos, Robson G.; Martins, Agnaldo Silva; Farias, Julyana da Nobrega; Horta, Antunes Paulo; Pinheiro, Hudson Tercio; Baptistotte, Cecilia; Seminoff, Jeffrey A.; Balazs, George H.; Work, Thierry M.

    2011-01-01

    To show the influence of coastal habitat degradation on the availability of food for green turtles (Chelonia mydas), we assessed the dietary preferences and macroalgae community at a feeding area in a highly urbanized region. The area showed low species richness and was classified as degraded. We examined stomach contents of 15 dead stranded turtles (CCL = 44.0 cm (SD 6.7 cm)). The diet was composed primarily of green algae Ulva spp. (83.6%). In contrast, the macroalgae community was dominated by the green alga Caulerpa mexicana. We found a selection for red algae, seagrass and Ulva spp., and avoidance for C. mexicana and brown alga Dictyopteris delicatula. The low diversity of available food items, possibly a result of environmental degradation, likely contributed to the low dietary diversity. The nutritional implications of this restricted diet are unclear.

  2. Remediation: DOE funding cut shakes MMT

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stringer, J.

    1996-10-30

    Molten Metal Technologies (MMT; Waltham, MA) announced last week that its 1993-97 R&D contract with the Department of Energy (DOE) would provide $12 million less next year than had been projected. The company was struck an additional blow when its stock plummeted more than 50% in three days on the news. MMT says that with tightened resources it will refocus attention on two core areas: chemical and radioactive wastes. The company says construction on some of its projects will be delayed, but an MMT unit that employs a molten metal bath to destroy wastes at a Hoechst plant at Baymore » City, TX and a planned unit at Celanese Mexicana`s Coatzacoalcos, Veracruz plant will go ahead. Those projects are slated to be completed by the end of 1997 and 1999, respectively.« less

  3. Nature Contacts: Employee Wellness in Healthcare.

    PubMed

    Trau, Deborah; Keenan, Kimberly A; Goforth, Meggan; Large, Vernon

    2016-04-01

    This study was designed to ascertain the amount of outdoor, indoor, and indirect nature contact exposures hospital employees have in a workweek. Hospital employees have been found particularly vulnerable to work-related stress. Increasing the nature contact exposure for hospital employees can reduce perceived stress; stress-related health behaviors; and stress-related health outcomes from outdoor, indoor, and indirect exposures to nature. Staff on the fourth floor postsurgical unit of a large hospital (N = 42) were ask to participate in an employee questionnaire "nature contact questionnaire". This 16-item nature environment questionnaire measures the amount and types of nature contact exposures employees have during a workweek. Majority of employees reported few, if any, nature contact exposures, specifically in the area of outdoor nature contacts with limited indoor and indirect contacts. These results indicated that employees on the fourth floor postsurgical floor have limited ability to reduce stress through nature contact exposures which could impact their perceived levels of work stress and stress-related behaviors and health outcomes. Nature contact exposures are both a relatively easy and an inexpensive way to improve employee stress. These findings indicate limitations to employees' exposure to nature contacts. Healthcare environments would benefit from a concerted effort to provide increased outdoor, indoor, and indirect nature contact exposures for employees. © The Author(s) 2015.

  4. Breast reconstruction - natural tissue

    MedlinePlus

    ... flap; TUG; Mastectomy - breast reconstruction with natural tissue; Breast cancer - breast reconstruction with natural tissue ... it harder to find a tumor if your breast cancer comes back. The advantage of breast reconstruction with ...

  5. Alternative Fuels Data Center: Natural Gas

    Science.gov Websites

    Natural Gas Printable Version Share this resource Send a link to Alternative Fuels Data Center : Natural Gas to someone by E-mail Share Alternative Fuels Data Center: Natural Gas on Facebook Tweet about Alternative Fuels Data Center: Natural Gas on Twitter Bookmark Alternative Fuels Data Center: Natural Gas on

  6. Glycosylation and Activities of Natural Products.

    PubMed

    Huang, Gangliang; Lv, Meijiao; Hu, Jinchuan; Huang, Kunlin; Xu, Hong

    2016-01-01

    Natural products are widely found in nature, their number and variety are numerous, the structures are complex and diverse. These natural products have many physiological and pharmacological activities. Glycosylation can increase the diversity of structure and function of natural product, it has become the focus of drug research and development. The impacts of glycosylation of natural products to water solubility, pharmacological activities, bioavailability, or others were described in this review, which provides a reference for the development and application of glycosylated natural products.

  7. Use of natural ingredients to control growth of Clostridium perfringens in naturally cured frankfurters and hams.

    PubMed

    Jackson, Armitra L; Kulchaiyawat, Charlwit; Sullivan, Gary A; Sebranek, Joseph G; Dickson, James S

    2011-03-01

    A major concern for processed meats marketed as natural/organic is that they do not contain nitrite in concentrations known to be most effective for inhibiting foodborne pathogens. Supplemental treatments to increase the level and consistency of antimicrobial protection in these products may be important to provide consumers with the degree of safety that they have come to expect from conventionally cured meats. Therefore, the objective of this study was to identify and test ingredients that might improve processed meat product safety without altering their natural/organic status. Eight treatments of hams and frankfurters were prepared: (A) uncured control (typical ingredients except nitrite and nitrate); (B) conventionally cured control (erythorbate, nitrite, and a lactate-diacetate blend); (C) natural nitrate cure (including starter culture containing Staphylococcus carnosus); (D) natural nitrate cure (culture and natural antimicrobial A containing a vinegar, lemon, and cherry powder blend); (E) natural nitrate cure (culture and antimicrobial B containing a cultured sugar and vinegar blend); (F) natural nitrite cure without additional antimicrobials; (G) natural nitrite cure with natural antimicrobial A; and (H) natural nitrite cure with antimicrobial B. For the hams, treatments C, D, E, and H impacted growth of Clostridium perfringens to the same extent (P < 0.05) as the conventionally cured control (approximately 2 log less growth over time than uncured control). For frankfurters, treatments D, G, and H had an effect (approximately 1 log) on growth equivalent to that of the conventionally cured control (P < 0.05). These results suggest that natural/organic cured meats have more potential for pathogen growth than conventionally cured products, but supplemental natural ingredients offer safety improvement.

  8. Natural knowledge as a propaedeutic to self-betterment: Francis Bacon and the transformation of natural history.

    PubMed

    Lancaster, James A T

    2012-01-01

    This paper establishes the 'emblematic' use of natural history as a propaedeutic to self-betterment in the Renaissance; in particular, in the natural histories of Gessner and Topsell, but also in the works of Erasmus and Rabelais. Subsequently, it investigates how Francis Bacon's conception of natural history is envisaged in relation to them. The paper contends that, where humanist natural historians understood the use of natural knowledge as a preliminary to individual improvement, Bacon conceived self-betterment foremost as a means to Christian charity, or social-betterment. It thus examines the transformation of the moralizing aspect of Renaissance natural history in Bacon's conception of his Great Instauration.

  9. Nest densities of cavity-nesting birds in relation to postfire salvage logging and time since wildfire

    Treesearch

    Victoria A. Saab; Robin E. Russell; Jonathan G. Dudley

    2007-01-01

    We monitored the nest densities and nest survival of seven cavity-nesting bird species, including four open-space foragers (American Kestrel [Falco sparverius], Lewis's Woodpecker [Melanerpes lewis], Western Bluebird [Sialia mexicana], and Mountain Bluebird [S. currucoides]) and three wood...

  10. Relationships among the spruces (Picea, Pinaceae) of southwestern North America

    Treesearch

    F. Thomas Ledig; Paul D. Hodgskiss; Konstanin V. Krutovskii; David B. Neale; Teobaldo Eguiluz-Piedra

    2004-01-01

    Numerous populations from six spruce taxa, including four relict endemics, Picea chihuahuana (Chihuahua spruce), P. martinezii (Martínez spruce), P. mexicana (Mexican spruce), and P. breweriana (Brewer spruce), and two widespread species, P. engelmannii (Engelmann spruce) and...

  11. Alaska Department of Natural Resources

    Science.gov Websites

    Department of Natural Resources logo Department of Natural Resources Office of Project Management & Restoration Coastal Impact Assistance Program Natural Resources / Office of Project Management & ; Permitting Welcome to the Office of Project Management & Permitting Large Project Coordination The

  12. 18 CFR 2.78 - Utilization and conservation of natural resources-natural gas.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Utilization and conservation of natural resources-natural gas. 2.78 Section 2.78 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES GENERAL POLICY AND...

  13. 18 CFR 2.78 - Utilization and conservation of natural resources-natural gas.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Utilization and conservation of natural resources-natural gas. 2.78 Section 2.78 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES GENERAL POLICY AND...

  14. 18 CFR 2.78 - Utilization and conservation of natural resources-natural gas.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Utilization and conservation of natural resources-natural gas. 2.78 Section 2.78 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES GENERAL POLICY AND...

  15. 18 CFR 2.78 - Utilization and conservation of natural resources-natural gas.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Utilization and conservation of natural resources-natural gas. 2.78 Section 2.78 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES GENERAL POLICY AND...

  16. Electrospinning of PVC with natural rubber

    NASA Astrophysics Data System (ADS)

    Othman, Muhammad Hariz; Mohamed, Mahathir; Abdullah, Ibrahim

    2013-11-01

    Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber's mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber.

  17. Nature and Nationhood: Danish Perspectives

    ERIC Educational Resources Information Center

    Schnack, Karsten

    2009-01-01

    In this paper, I shall discuss Danish perspectives on nature, showing the interdependence of conceptions of "nature" and "nationhood" in the formations of a particular cultural community. Nature, thus construed, is never innocent of culture and cannot therefore simply be "restored" to some pristine, pre-lapsarian…

  18. Natural pet food: a review of natural diets and their impact on canine and feline physiology.

    PubMed

    Buff, P R; Carter, R A; Bauer, J E; Kersey, J H

    2014-09-01

    The purpose of this review is to clarify the definition of "natural" as it pertains to commercial pet food and to summarize the scientific findings related to natural ingredients in pet foods and natural diets on the impact of pet health and physiology. The term "natural," when used to market commercial pet foods or pet food ingredients in the United States, has been defined by the Association of American Feed Control Officials and requires, at minimum, that the pet food be preserved with natural preservatives. However, pet owners may consider natural as something different than the regulatory definition. The natural pet food trend has focused on the inclusion of whole ingredients, including meats, fruits, and vegetables; avoiding ingredients perceived as heavily processed, including refined grains, fiber sources, and byproducts; and feeding according to ancestral or instinctual nutritional philosophies. Current scientific evidence supporting nutritional benefits of natural pet food products is limited to evaluations of dietary macronutrient profiles, fractionation of ingredients, and the processing of ingredients and final product. Domestic cats select a macronutrient profile (52% of ME from protein) similar to the diet of wild cats. Dogs have evolved much differently in their ability to metabolize carbohydrates and select a diet lower in protein (30% of ME from protein) than the diet of wild wolves. The inclusion of whole food ingredients in natural pet foods as opposed to fractionated ingredients may result in higher nutrient concentrations, including phytonutrients. Additionally, the processing of commercial pet food can impact digestibility, nutrient bioavailability, and safety, which are particularly important considerations with new product formats in the natural pet food category. Future opportunities exist to better understand the effect of natural diets on health and nutrition outcomes and to better integrate sustainable practices in the production of

  19. Natural gas annual 1996

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1997-09-01

    This document provides information on the supply and disposition of natural gas to a wide audience. The 1996 data are presented in a sequence that follows natural gas from it`s production to it`s end use.

  20. Arguing from Nature: The role of `nature' in students' argumentations on a socio-scientific issue

    NASA Astrophysics Data System (ADS)

    Nielsen, Jan Alexis

    2012-03-01

    This paper explores how students invoked different conceptions of 'nature' in eight socio-scientific group discussions about human gene therapy. The paper illustrates and discusses how the students articulated nature and to what extent they elicited science factual content in the process. While the students in this study invoked nature at key places in a variety of dialectical contexts in the discussions, these invocations were often uncritical appeals and rarely involved science factual content. Even when an argument from nature was challenged, the author of that argument would often shift the sense of nature rather than elaborate upon the argumentation. It is argued that if students were properly introduced to the evaluative character of the term 'nature' it would not just be conducive to the quality of their argumentation, but also invite them to foreground science factual content at key places in their discussion.

  1. Nature-Based Solutions in the EU: Innovating with nature to address social, economic and environmental challenges.

    PubMed

    Faivre, Nicolas; Fritz, Marco; Freitas, Tiago; de Boissezon, Birgit; Vandewoestijne, Sofie

    2017-11-01

    Contemporary societies are facing a broad range of challenges, from pressures on human health and well-being to natural capital depletion, and the security of food, water and energy. These challenges are deeply intertwined with global processes, such as climate change and with local events such as natural disasters. The EU's research & innovation (R&I) policy is now seeking to address these challenges from a new perspective, with Nature-Based Solutions, and turn them into innovation opportunities that optimise the synergies between nature, society and the economy. Nature-Based Solutions can be an opportunity for innovation, and are here promoted by both policymakers and practitioners as a cost-effective way of creating a greener, more sustainable, and more competitive economy. Since 2013, the European Commission has devoted particular attention to Nature-Based Solutions through consultations and dialogues that sought to make the concept of these solutions more concrete and to define the concept's place within the spectrum of ecosystem-based approaches. In 2014, the Commission launched an expert group, which conducted further analysis, and made recommendations to help increase the use of Nature-Based Solutions and bring nature back into cities. In 2015, a survey was conducted on citizens' views and perceptions of 'Nature in Cities' to provide further insight for future work. Based on these elements and on results from running EU projects, the Commission has developed an R&I agenda for Nature-Based Solutions and has published targeted calls for proposals for large-scale demonstration projects in this field in 2016 and 2017. Additional R&I actions at EU level that promote systemic Nature-Based Solutions and their benefits to cities and territories are planned with the aim to improve the implementation capacity and evidence base for deploying Nature-Based Solutions and developing corresponding future markets. They are also expected to foster an interdisciplinary R

  2. Natural Resource Damages: Trustees

    EPA Pesticide Factsheets

    CERCLA and OPA authorize the United States, States, and Indian Tribes to act on behalf of the public as Natural Resource Trustees for natural resources under their respective trusteeship. OPA also authorizes foreign governments to act as Trustees.

  3. Naturalness and Animal Welfare.

    PubMed

    Yeates, James

    2018-04-05

    Naturalness is considered important for animals, and is one criterion for assessing how we care for them. However, it is a vague and ambiguous term, which needs definition and assessments suitable for scientific and ethical questions. This paper makes a start on that aim. This paper differentiates the term from other related concepts, such as species-typical behaviour and wellbeing. It identifies contingent ways in which naturalness might be used, as: (i) prompts for further welfare assessment; (ii) a plausible hypothesis for what safeguards wellbeing; (iii) a threshold for what is acceptable; (iv) constraints on what improvements are unacceptable; and (v) demarcating what is not morally wrong, because of a lack of human agency. It then suggests an approach to evaluating animals' behaviour that is quantitative, is based on reality, and which assesses naturalness by degrees. It proposes classing unaffected wild populations as natural by definition. Where animals might have been affected by humans, they should be compared to the closest population(s) of unaffected animals. This approach could allow us both to assess naturalness scientifically, and to make practical decisions about the behaviour of domestic animals.

  4. Fabrication of Nanolaminates with Ultrathin Nanolayers Using Atomic Layer Deposition: Nucleation & Growth Issues

    DTIC Science & Technology

    2009-02-01

    Tecnologia de Superficies y Materiales (SMCTSM), XXVII Congreso Nacional, Oaxaca, Oaxaca, Mexico, September 26, 2007. 26. "Atomic Layer Deposition of...Nanolaminates: Fabrication and Properties" (Plenary Lecture), Sociedad Mexicana de Ciencia y Tecnologia de Superficies y Materiales (SMCTSM), XXVII

  5. Electrospinning of PVC with natural rubber

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Othman, Muhammad Hariz; Abdullah, Ibrahim; Mohamed, Mahathir

    Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber’s mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphologymore » and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber.« less

  6. The Rediscovery of a Long Described Species Reveals Additional Complexity in Speciation Patterns of Poeciliid Fishes in Sulfide Springs

    PubMed Central

    Palacios, Maura; Arias-Rodriguez, Lenin; Plath, Martin; Eifert, Constanze; Lerp, Hannes; Lamboj, Anton; Voelker, Gary; Tobler, Michael

    2013-01-01

    The process of ecological speciation drives the evolution of locally adapted and reproductively isolated populations in response to divergent natural selection. In Southern Mexico, several lineages of the freshwater fish species of the genus Poecilia have independently colonized toxic, hydrogen sulfide-rich springs. Even though ecological speciation processes are increasingly well understood in this system, aligning the taxonomy of these fish with evolutionary processes has lagged behind. While some sulfide spring populations are classified as ecotypes of Poecilia mexicana, others, like P. sulphuraria, have been described as highly endemic species. Our study particularly focused on elucidating the taxonomy of the long described sulfide spring endemic, Poecilia thermalis Steindachner 1863, and investigates if similar evolutionary patterns of phenotypic trait divergence and reproductive isolation are present as observed in other sulfidic species of Poecilia. We applied a geometric morphometric approach to assess body shape similarity to other sulfidic and non-sulfidic fish of the genus Poecilia. We also conducted phylogenetic and population genetic analyses to establish the phylogenetic relationships of P. thermalis and used a population genetic approach to determine levels of gene flow among Poecilia from sulfidic and non-sulfidic sites. Our results indicate that P. thermalis' body shape has evolved in convergence with other sulfide spring populations in the genus. Phylogenetic analyses placed P. thermalis as most closely related to one population of P. sulphuraria, and population genetic analyses demonstrated that P. thermalis is genetically isolated from both P. mexicana ecotypes and P. sulphuraria. Based on these findings, we make taxonomic recommendations for P. thermalis. Overall, our study verifies the role of hydrogen sulfide as a main factor shaping convergent, phenotypic evolution and the emergence of reproductive isolation between Poecilia populations

  7. Locally adapted fish populations maintain small-scale genetic differentiation despite perturbation by a catastrophic flood event

    PubMed Central

    2010-01-01

    Background Local adaptation to divergent environmental conditions can promote population genetic differentiation even in the absence of geographic barriers and hence, lead to speciation. Perturbations by catastrophic events, however, can distort such parapatric ecological speciation processes. Here, we asked whether an exceptionally strong flood led to homogenization of gene pools among locally adapted populations of the Atlantic molly (Poecilia mexicana, Poeciliidae) in the Cueva del Azufre system in southern Mexico, where two strong environmental selection factors (darkness within caves and/or presence of toxic H2S in sulfidic springs) drive the diversification of P. mexicana. Nine nuclear microsatellites as well as heritable female life history traits (both as a proxy for quantitative genetics and for trait divergence) were used as markers to compare genetic differentiation, genetic diversity, and especially population mixing (immigration and emigration) before and after the flood. Results Habitat type (i.e., non-sulfidic surface, sulfidic surface, or sulfidic cave), but not geographic distance was the major predictor of genetic differentiation. Before and after the flood, each habitat type harbored a genetically distinct population. Only a weak signal of individual dislocation among ecologically divergent habitat types was uncovered (with the exception of slightly increased dislocation from the Cueva del Azufre into the sulfidic creek, El Azufre). By contrast, several lines of evidence are indicative of increased flood-induced dislocation within the same habitat type, e.g., between different cave chambers of the Cueva del Azufre. Conclusions The virtual absence of individual dislocation among ecologically different habitat types indicates strong natural selection against migrants. Thus, our current study exemplifies that ecological speciation in this and other systems, in which extreme environmental factors drive speciation, may be little affected by temporary

  8. Locally adapted fish populations maintain small-scale genetic differentiation despite perturbation by a catastrophic flood event.

    PubMed

    Plath, Martin; Hermann, Bernd; Schröder, Christiane; Riesch, Rüdiger; Tobler, Michael; García de León, Francisco J; Schlupp, Ingo; Tiedemann, Ralph

    2010-08-23

    Local adaptation to divergent environmental conditions can promote population genetic differentiation even in the absence of geographic barriers and hence, lead to speciation. Perturbations by catastrophic events, however, can distort such parapatric ecological speciation processes. Here, we asked whether an exceptionally strong flood led to homogenization of gene pools among locally adapted populations of the Atlantic molly (Poecilia mexicana, Poeciliidae) in the Cueva del Azufre system in southern Mexico, where two strong environmental selection factors (darkness within caves and/or presence of toxic H2S in sulfidic springs) drive the diversification of P. mexicana. Nine nuclear microsatellites as well as heritable female life history traits (both as a proxy for quantitative genetics and for trait divergence) were used as markers to compare genetic differentiation, genetic diversity, and especially population mixing (immigration and emigration) before and after the flood. Habitat type (i.e., non-sulfidic surface, sulfidic surface, or sulfidic cave), but not geographic distance was the major predictor of genetic differentiation. Before and after the flood, each habitat type harbored a genetically distinct population. Only a weak signal of individual dislocation among ecologically divergent habitat types was uncovered (with the exception of slightly increased dislocation from the Cueva del Azufre into the sulfidic creek, El Azufre). By contrast, several lines of evidence are indicative of increased flood-induced dislocation within the same habitat type, e.g., between different cave chambers of the Cueva del Azufre. The virtual absence of individual dislocation among ecologically different habitat types indicates strong natural selection against migrants. Thus, our current study exemplifies that ecological speciation in this and other systems, in which extreme environmental factors drive speciation, may be little affected by temporary perturbations, as adaptations

  9. Can Nature Protection be Unsustainable? Models Behind Nature Protection in New Zealands National Parks

    NASA Astrophysics Data System (ADS)

    Hauhs, Michael; Bogner, Christina

    2013-04-01

    Nature protection can be justified by intrinsic values of life. Western culture sees nature as an autonomous system. Thus, nature protection is often synonymous with refraining from human interference as much as possible. This, however, can pose at least technical problems. Indeed, historical human impacts such as introduced species are often irreversible. In such cases refraining from human interference to protect threatened species is not an adequate management response. Nature protection in New Zealand is a prominent example. Many introduced species make a non-interventionist attitude infeasible to protect endemic species such as kiwis. Actually, active human interference is necessary to attain this goal. Therefore, one may consider nature protection as another form of land use. As any other form of land use, it needs standards of proper management (i.e. explicit goals, assessment, intervention etc.). In other words, it has to be shown to be sustainable. However, sustainability may rigorously be defined as an attribute of past land use only. Instantaneous positive indicators of sustainability may be elusive. At best it can be decided by observation whether or not a land use has been (not) sustainable until now. Stakeholders of nature protection have often different (implicit) concepts or models of nature in mind. This can lead to conflicts when it comes to management decisions. For example, the methods by which conservationists in New Zealand seek to re-establish historical species assemblages (e.g. aerial drop of poison into national parks) have come under criticism of animal rights groups as non-humane. We propose to use abstract modelling language to classify these concepts of nature protection and related issues. We show that from modelling perspective these conflicts pose a basic science problem rather than an applied science problem. This makes the delegation into existing disciplines so hard. We discuss possible implications for nature protection

  10. Percents Are Not Natural Numbers

    ERIC Educational Resources Information Center

    Jacobs, Jennifer A.

    2013-01-01

    Adults are prone to treating percents, one representational format of rational numbers, as novel cases of natural number. This suggests that percent values are not differentiated from natural numbers; a conceptual shift from the natural numbers to the rational numbers has not yet occurred. This is most surprising, considering people are inundated…

  11. 34 CFR 303.18 - Natural environments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Natural environments. 303.18 Section 303.18 Education... DISABILITIES General Purpose, Eligibility, and Other General Provisions § 303.18 Natural environments. As used in this part, natural environments means settings that are natural or normal for the child's age...

  12. 34 CFR 303.18 - Natural environments.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 2 2011-07-01 2010-07-01 true Natural environments. 303.18 Section 303.18 Education... DISABILITIES General Purpose, Eligibility, and Other General Provisions § 303.18 Natural environments. As used in this part, natural environments means settings that are natural or normal for the child's age...

  13. Reduced opsin gene expression in a cave-dwelling fish

    PubMed Central

    Tobler, Michael; Coleman, Seth W.; Perkins, Brian D.; Rosenthal, Gil G.

    2010-01-01

    Regressive evolution of structures associated with vision in cave-dwelling organisms is the focus of intense research. Most work has focused on differences between extreme visual phenotypes: sighted, surface animals and their completely blind, cave-dwelling counterparts. We suggest that troglodytic systems, comprising multiple populations that vary along a gradient of visual function, may prove critical in understanding the mechanisms underlying initial regression in visual pathways. Gene expression assays of natural and laboratory-reared populations of the Atlantic molly (Poecilia mexicana) revealed reduced opsin expression in cave-dwelling populations compared with surface-dwelling conspecifics. Our results suggest that the reduction in opsin expression in cave-dwelling populations is not phenotypically plastic but reflects a hardwired system not rescued by exposure to light during retinal ontogeny. Changes in opsin gene expression may consequently represent a first evolutionary step in the regression of eyes in cave organisms. PMID:19740890

  14. Divergent Evolution of Male Aggressive Behaviour: Another Reproductive Isolation Barrier in Extremophile Poeciliid Fishes?

    PubMed Central

    Bierbach, David; Klein, Moritz; Saßmannshausen, Vanessa; Schlupp, Ingo; Riesch, Rüdiger; Parzefall, Jakob; Plath, Martin

    2012-01-01

    Reproductive isolation among locally adapted populations may arise when immigrants from foreign habitats are selected against via natural or (inter-)sexual selection (female mate choice). We asked whether also intrasexual selection through male-male competition could promote reproductive isolation among populations of poeciliid fishes that are locally adapted to extreme environmental conditions [i.e., darkness in caves and/or toxic hydrogen sulphide (H2S)]. We found strongly reduced aggressiveness in extremophile P. oecilia mexicana, and darkness was the best predictor for the evolutionary reduction of aggressiveness, especially when combined with presence of H2S. We demonstrate that reduced aggression directly translates into migrant males being inferior when paired with males from non-sulphidic surface habitats. By contrast, the phylogenetically old sulphur endemic P. sulphuraria from another sulphide spring area showed no overall reduced aggressiveness, possibly indicating evolved mechanisms to better cope with H2S. PMID:22315695

  15. [Reconstruction of the ear in the burns patient].

    PubMed

    Carrillo-Córdova, Jorge Raúl; Jiménez Murat, Yusef; Apellaniz-Campo, Armando; Bracho-Olvera, Hazel; Carrillo Esper, Raúl

    Face burns are a singular pathology with great functional and psychological impact in the patients suffering them. The ears play a fundamental role in personal interactions and damage to this organ results in physical and emotional distress. The reconstructive treatment of the burned ear is a challenge. Multiple procedures have been described to achieve success in the reconstruction of the burned ear; immediate reconstruction with autologous rib cartilage, secondary reconstruction, alloplastic material reconstruction, tissue expansion, skin grafts and also microvascular flaps are some of the most common procedures used in this patients. All these techniques focus on giving a natural appearance to the patient. Burns to the ears affect 30% of the patients with facial burns, they require an excellent treatment given by a multidisciplinary team. Copyright © 2017 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  16. Natural product mode of action (MOA) studies: a link between natural and synthetic worlds.

    PubMed

    La Clair, James J

    2010-07-01

    In our understanding of matter, natural products deliver plots that would stun even the best productions of the legendary filmmaker, Sergio Leone. While every decade heralds a new genre of film (as well as avenues of small-molecule discovery), natural products and their "untamed prehistoric" plots continue to dazzle the fields of biotechnology, drug discovery, fragrances, food additives and agrochemistry. This review provides an abridged synopsis of the modes of natural product action discovered within the last decade and the tools and methods used in their discovery. Their stories are united in a common theme that unveils one of the more vital aspects of chemical biological research:understanding the global activity of Nature's arsenal of secondary metabolites.

  17. Can nature make us more caring? Effects of immersion in nature on intrinsic aspirations and generosity.

    PubMed

    Weinstein, Netta; Przybylski, Andrew K; Ryan, Richard M

    2009-10-01

    Four studies examined the effects of nature on valuing intrinsic and extrinsic aspirations. Intrinsic aspirations reflected prosocial and other-focused value orientations, and extrinsic aspirations predicted self-focused value orientations. Participants immersed in natural environments reported higher valuing of intrinsic aspirations and lower valuing of extrinsic aspirations, whereas those immersed in non-natural environments reported increased valuing of extrinsic aspirations and no change of intrinsic aspirations. Three studies explored experiences of nature relatedness and autonomy as underlying mechanisms of these effects, showing that nature immersion elicited these processes whereas non-nature immersion thwarted them and that they in turn predicted higher intrinsic and lower extrinsic aspirations. Studies 3 and 4 also extended the paradigm by testing these effects on generous decision making indicative of valuing intrinsic versus extrinsic aspirations.

  18. Children's Moral Relationships with Nature.

    ERIC Educational Resources Information Center

    Kahn, Peter H., Jr.; McCoy, Ann

    Two studies of the development of children's moral relationships with nature addressed such questions as: (1) What does it mean to say that we have an obligation not to harm the natural environment? (2) Does the natural environment feel pain? (3) Does it have rights? or (4) Is moral obligation an inappropriate construct by which to understand the…

  19. On the meanings of "nature"

    Treesearch

    Calvin W. Stillman

    1977-01-01

    All peoples known to science have a concept of "nature" which forms part of the world-view of the culture. The relative importance of "nature" differs among cultures. In our own Western culture, ideas of "nature" are mentioned from the earliest written records, and are related to concepts of the autonomous individual and of hierarachy and...

  20. Naturalness as an Educational Value

    ERIC Educational Resources Information Center

    Frolund, Sune

    2016-01-01

    Existentialism and postmodernism have both abandoned the idea of a human nature. Also, the idea of naturalness as a value for education has been targeted as a blind for conservative ideology. There are, however, good reasons to re-establish a sound concept of human naturalness. First of all, the concept does not seem to have disappeared from…

  1. [Are Mental Disorders Natural Kinds?].

    PubMed

    Flórez Quintero, Daian Tatiana

    2015-01-01

    A problem for both philosophers of Psychiatry and Psychiatrists within the domain of nosology is to determine which could be the more appropriate model to classify mental illnesses. Such an endeavor also requires questioning the very nature of mental illness. While trying to cope with the philosophical challenges of such a task, Peter Zachar purports to show that the nosological work in Psychiatry should not adhere to the model of natural kinds. He even considers that it is mistaken to treat mental disorders as natural kinds. Nonetheless, Zachar's view on the existence of natural kinds-even in domains where there is little room for doubting about their existence, like Chemistry-is very unstable. In 2001 he holds that there are no natural kinds, but in 2008 he argues that his objections to the model of natural kinds are more the manifestation of his skepticism against a tradition. Although the problem of the existence of natural kinds shall not be dealt with in this article, a brief description on how deflated is Zachar's view on this matter in 2008 is presented, with the central part of the article devoted to reconstruct and examine his rationale for the thesis that mental disorders are not natural kinds. In the critical section of this paper, it is suggested that, although Zachar's thesis may be right, the arguments he gives to support it are quite flawed. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  2. Arguing from Nature: The Role of "Nature" in Students' Argumentations on a Socio-Scientific Issue

    ERIC Educational Resources Information Center

    Nielsen, Jan Alexis

    2012-01-01

    This paper explores how students invoked different conceptions of "nature" in eight socio-scientific group discussions about human gene therapy. The paper illustrates and discusses how the students articulated nature and to what extent they elicited science factual content in the process. While the students in this study invoked nature at key…

  3. Natural Resource Management Plan

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Green, T.; Schwager, K.

    This comprehensive Natural Resource Management Plan (NRMP) for Brookhaven National Laboratory (BNL) was built on the successful foundation of the Wildlife Management Plan for BNL, which it replaces. This update to the 2003 plan continues to build on successes and efforts to better understand the ecosystems and natural resources found on the BNL site. The plan establishes the basis for managing the varied natural resources located on the 5,265-acre BNL site, setting goals and actions to achieve those goals. The planning of this document is based on the knowledge and expertise gained over the past 15 years by the Naturalmore » Resources management staff at BNL in concert with local natural resource agencies including the New York State Department of Environmental Conservation, Long Island Pine Barrens Joint Planning and Policy Commission, The Nature Conservancy, and others. The development of this plan works toward sound ecological management that not only benefits BNL’s ecosystems but also benefits the greater Pine Barrens habitats in which BNL is situated. This plan applies equally to the Upton Ecological and Research Reserve (Upton Reserve). Any difference in management between the larger BNL area and the Upton Reserve are noted in the text.« less

  4. An automated Genomes-to-Natural Products platform (GNP) for the discovery of modular natural products.

    PubMed

    Johnston, Chad W; Skinnider, Michael A; Wyatt, Morgan A; Li, Xiang; Ranieri, Michael R M; Yang, Lian; Zechel, David L; Ma, Bin; Magarvey, Nathan A

    2015-09-28

    Bacterial natural products are a diverse and valuable group of small molecules, and genome sequencing indicates that the vast majority remain undiscovered. The prediction of natural product structures from biosynthetic assembly lines can facilitate their discovery, but highly automated, accurate, and integrated systems are required to mine the broad spectrum of sequenced bacterial genomes. Here we present a genome-guided natural products discovery tool to automatically predict, combinatorialize and identify polyketides and nonribosomal peptides from biosynthetic assembly lines using LC-MS/MS data of crude extracts in a high-throughput manner. We detail the directed identification and isolation of six genetically predicted polyketides and nonribosomal peptides using our Genome-to-Natural Products platform. This highly automated, user-friendly programme provides a means of realizing the potential of genetically encoded natural products.

  5. Natural Hazards - A National Threat

    USGS Publications Warehouse

    Geological Survey, U.S.

    2007-01-01

    The USGS Role in Reducing Disaster Losses -- In the United States each year, natural hazards cause hundreds of deaths and cost billions of dollars in disaster aid, disruption of commerce, and destruction of homes and critical infrastructure. Although the number of lives lost to natural hazards each year generally has declined, the economic cost of major disaster response and recovery continues to rise. Each decade, property damage from natural hazards events doubles or triples. The United States is second only to Japan in economic damages resulting from natural disasters. A major goal of the U.S. Geological Survey (USGS) is to reduce the vulnerability of the people and areas most at risk from natural hazards. Working with partners throughout all sectors of society, the USGS provides information, products, and knowledge to help build more resilient communities.

  6. 21 CFR 582.30 - Natural substances used in conjunction with spices and other natural seasonings and flavorings.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Natural substances used in conjunction with spices... with spices and other natural seasonings and flavorings. Natural substances used in conjunction with spices and other natural seasonings and flavorings that are generally recognized as safe for their...

  7. The nature-disorder paradox: A perceptual study on how nature is disorderly yet aesthetically preferred.

    PubMed

    Kotabe, Hiroki P; Kardan, Omid; Berman, Marc G

    2017-08-01

    Natural environments have powerful aesthetic appeal linked to their capacity for psychological restoration. In contrast, disorderly environments are aesthetically aversive, and have various detrimental psychological effects. But in our research, we have repeatedly found that natural environments are perceptually disorderly. What could explain this paradox? We present 3 competing hypotheses: the aesthetic preference for naturalness is more powerful than the aesthetic aversion to disorder (the nature-trumps-disorder hypothesis ); disorder is trivial to aesthetic preference in natural contexts (the harmless-disorder hypothesis ); and disorder is aesthetically preferred in natural contexts (the beneficial-disorder hypothesis ). Utilizing novel methods of perceptual study and diverse stimuli, we rule in the nature-trumps-disorder hypothesis and rule out the harmless-disorder and beneficial-disorder hypotheses. In examining perceptual mechanisms, we find evidence that high-level scene semantics are both necessary and sufficient for the nature-trumps-disorder effect. Necessity is evidenced by the effect disappearing in experiments utilizing only low-level visual stimuli (i.e., where scene semantics have been removed) and experiments utilizing a rapid-scene-presentation procedure that obscures scene semantics. Sufficiency is evidenced by the effect reappearing in experiments utilizing noun stimuli which remove low-level visual features. Furthermore, we present evidence that the interaction of scene semantics with low-level visual features amplifies the nature-trumps-disorder effect-the effect is weaker both when statistically adjusting for quantified low-level visual features and when using noun stimuli which remove low-level visual features. These results have implications for psychological theories bearing on the joint influence of low- and high-level perceptual inputs on affect and cognition, as well as for aesthetic design. (PsycINFO Database Record (c) 2017 APA, all

  8. Efficiency and establishment of three introduced parasitoids of the mealybug Paracoccus marginatus (Hemiptera: Pseudococcidae)

    USDA-ARS?s Scientific Manuscript database

    A study on the efficiency and establishment of three previously introduced parasitoids (Acerophagus papayae, Anagyrus loecki, and Pseudleptomastix mexicana) to control the mealybug Paracoccus marginatus was made in 2005 and 2006, at three locations in Homestead (Miami-Dade County), Florida. In each ...

  9. 78 FR 38309 - Northern Natural Gas Company; Southern Natural Gas Company, L.L.C.; Florida Gas Transmission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-26

    ... Natural Gas Company; Southern Natural Gas Company, L.L.C.; Florida Gas Transmission Company, LLC; Notice of Application Take notice that on June 4, 2013, Northern Natural Gas Company (Northern), 1111 South 103rd Street, Omaha, Nebraska 68124; on behalf of itself, Southern Natural Gas Company, L.L.C., and...

  10. 76 FR 4417 - Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-25

    ... DEPARTMENT OF TRANSPORTATION Maritime Administration [USCG-2010-0993] Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License Application AGENCY: Maritime Administration... application describes an offshore natural gas deepwater port facility that would be located approximately 16.2...

  11. 75 FR 70350 - Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-17

    ... DEPARTMENT OF TRANSPORTATION Maritime Administration [USCG-2010-0993] Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License Application AGENCY: Maritime Administration... announce they have received an application for the licensing of a natural gas deepwater port and the...

  12. Geographic Distribution of Leishmania Species in Ecuador Based on the Cytochrome B Gene Sequence Analysis.

    PubMed

    Kato, Hirotomo; Gomez, Eduardo A; Martini-Robles, Luiggi; Muzzio, Jenny; Velez, Lenin; Calvopiña, Manuel; Romero-Alvarez, Daniel; Mimori, Tatsuyuki; Uezato, Hiroshi; Hashiguchi, Yoshihisa

    2016-07-01

    A countrywide epidemiological study was performed to elucidate the current geographic distribution of causative species of cutaneous leishmaniasis (CL) in Ecuador by using FTA card-spotted samples and smear slides as DNA sources. Putative Leishmania in 165 samples collected from patients with CL in 16 provinces of Ecuador were examined at the species level based on the cytochrome b gene sequence analysis. Of these, 125 samples were successfully identified as Leishmania (Viannia) guyanensis, L. (V.) braziliensis, L. (V.) naiffi, L. (V.) lainsoni, and L. (Leishmania) mexicana. Two dominant species, L. (V.) guyanensis and L. (V.) braziliensis, were widely distributed in Pacific coast subtropical and Amazonian tropical areas, respectively. Recently reported L. (V.) naiffi and L. (V.) lainsoni were identified in Amazonian areas, and L. (L.) mexicana was identified in an Andean highland area. Importantly, the present study demonstrated that cases of L. (V.) braziliensis infection are increasing in Pacific coast areas.

  13. US Vulnerability to Natural Disasters

    NASA Astrophysics Data System (ADS)

    van der Vink, G.; Apgar, S.; Batchelor, A.; Carter, C.; Gail, D.; Jarrett, A.; Levine, N.; Morgan, W.; Orlikowski, M.; Pray, T.; Raymar, M.; Siebert, A.; Shawa, T. W.; Wallace, C.

    2002-05-01

    Natural disasters result from the coincidence of natural events with the built environment. Our nation's infrastructure is growing at an exponential rate in many areas of high risk, and the Federal government's liability is increasing proportionally. By superimposing population density with predicted ground motion from earthquakes, historical hurricane tracks, historical tornado locations, and areas within the flood plain, we are able to identify locations of high vulnerability within the United States. We present a comprehensive map of disaster risk for the United States that is being produced for the Senate Natural Hazards Caucus. The map allows for the geographic comparison of natural disaster risk with past disaster declarations, the expenditure of Federal dollars for disaster relief, population increase, and variations of GDP. Every state is vulnerable to natural disasters. Although their frequency varies considerably, the annualized losses for disaster relief from hurricanes, earthquakes, and floods are approximately equivalent. While fast-growing states such as California and Florida remain highly vulnerable, changes in the occurrence of natural events combined with population increases are making areas such as Texas, North Carolina, and the East Coast increasingly vulnerable.

  14. Natural gas-assisted steam electrolyzer

    DOEpatents

    Pham, Ai-Quoc; Wallman, P. Henrik; Glass, Robert S.

    2000-01-01

    An efficient method of producing hydrogen by high temperature steam electrolysis that will lower the electricity consumption to an estimated 65 percent lower than has been achievable with previous steam electrolyzer systems. This is accomplished with a natural gas-assisted steam electrolyzer, which significantly reduces the electricity consumption. Since this natural gas-assisted steam electrolyzer replaces one unit of electrical energy by one unit of energy content in natural gas at one-quarter the cost, the hydrogen production cost will be significantly reduced. Also, it is possible to vary the ratio between the electricity and the natural gas supplied to the system in response to fluctuations in relative prices for these two energy sources. In one approach an appropriate catalyst on the anode side of the electrolyzer will promote the partial oxidation of natural gas to CO and hydrogen, called Syn-Gas, and the CO can also be shifted to CO.sub.2 to give additional hydrogen. In another approach the natural gas is used in the anode side of the electrolyzer to burn out the oxygen resulting from electrolysis, thus reducing or eliminating the potential difference across the electrolyzer membrane.

  15. Nature/culture/seawater.

    PubMed

    Helmreich, Stefan

    2011-01-01

    Seawater has occupied an ambiguous place in anthropological categories of "nature" and "culture." Seawater as nature appears as potentiality of form and uncontainable flux; it moves faster than culture - with culture frequently figured through land-based metaphors - even as culture seeks to channel water's (nature's) flow. Seawater as culture manifests as a medium of pleasure, sustenance, travel, disaster. I argue that, although seawater's qualities in early anthropology were portrayed impressionistically, today technical, scientific descriptions of water's form prevail. For example, processes of globalization - which may also be called "oceanization" - are often described as "currents," "flows," and "circulations." Examining sea-set ethnography, maritime anthropologies, and contemporary social theory, I propose that seawater has operated as a “theory machine” for generating insights about human cultural organization. I develop this argument with ethnography from the Sargasso Sea and in the Sea Islands. I conclude with a critique of appeals to water's form in social theory.

  16. An Individual’s Connection to Nature Can Affect Perceived Restorativeness of Natural Environments. Some Observations about Biophilia

    PubMed Central

    Berto, Rita; Barbiero, Giuseppe; Barbiero, Pietro

    2018-01-01

    This study investigates the relationship between the level to which a person feels connected to Nature and that person’s ability to perceive the restorative value of a natural environment. We assume that perceived restorativeness may depend on an individual’s connection to Nature and this relationship may also vary with the biophilic quality of the environment, i.e., the functional and aesthetic value of the natural environment which presumably gave an evolutionary advantage to our species. To this end, the level of connection to Nature and the perceived restorativeness of the environment were assessed in individuals visiting three parks characterized by their high level of “naturalness” and high or low biophilic quality. The results show that the perceived level of restorativeness is associated with the sense of connection to Nature, as well as the biophilic quality of the environment: individuals with different degrees of connection to Nature seek settings with different degrees of restorativeness and biophilic quality. This means that perceived restorativeness can also depend on an individual’s “inclination” towards Nature. PMID:29510581

  17. Living in cities, naturally.

    PubMed

    Hartig, Terry; Kahn, Peter H

    2016-05-20

    Natural features, settings, and processes in urban areas can help to reduce stress associated with urban life. In this and other ways, public health benefits from, street trees, green roofs, community gardens, parks and open spaces, and extensive connective pathways for walking and biking. Such urban design provisions can also yield ecological benefits, not only directly but also through the role they play in shaping attitudes toward the environment and environmental protection. Knowledge of the psychological benefits of nature experience supports efforts to better integrate nature into the architecture, infrastructure, and public spaces of urban areas. Copyright © 2016, American Association for the Advancement of Science.

  18. IUCN (International Union for Conservation of Nature and Natural Resources) Yearbook, 1975-76.

    ERIC Educational Resources Information Center

    International Union for Conservation of Nature and Natural Resources, Morges, (Switzerland).

    This yearbook covers the period from January 1975 to May 1976. It reviews the International Union for Conservation of Nature and Natural Resources' (IUCN) conservation strategy for the coming years, important international conservation treaties, IUCN organizational reforms, and the financial report for 1975. Conservation discussions include…

  19. The Effectiveness, Costs and Coastal Protection Benefits of Natural and Nature-Based Defences.

    PubMed

    Narayan, Siddharth; Beck, Michael W; Reguero, Borja G; Losada, Iñigo J; van Wesenbeeck, Bregje; Pontee, Nigel; Sanchirico, James N; Ingram, Jane Carter; Lange, Glenn-Marie; Burks-Copes, Kelly A

    2016-01-01

    There is great interest in the restoration and conservation of coastal habitats for protection from flooding and erosion. This is evidenced by the growing number of analyses and reviews of the effectiveness of habitats as natural defences and increasing funding world-wide for nature-based defences-i.e. restoration projects aimed at coastal protection; yet, there is no synthetic information on what kinds of projects are effective and cost effective for this purpose. This paper addresses two issues critical for designing restoration projects for coastal protection: (i) a synthesis of the costs and benefits of projects designed for coastal protection (nature-based defences) and (ii) analyses of the effectiveness of coastal habitats (natural defences) in reducing wave heights and the biophysical parameters that influence this effectiveness. We (i) analyse data from sixty-nine field measurements in coastal habitats globally and examine measures of effectiveness of mangroves, salt-marshes, coral reefs and seagrass/kelp beds for wave height reduction; (ii) synthesise the costs and coastal protection benefits of fifty-two nature-based defence projects and; (iii) estimate the benefits of each restoration project by combining information on restoration costs with data from nearby field measurements. The analyses of field measurements show that coastal habitats have significant potential for reducing wave heights that varies by habitat and site. In general, coral reefs and salt-marshes have the highest overall potential. Habitat effectiveness is influenced by: a) the ratios of wave height-to-water depth and habitat width-to-wavelength in coral reefs; and b) the ratio of vegetation height-to-water depth in salt-marshes. The comparison of costs of nature-based defence projects and engineering structures show that salt-marshes and mangroves can be two to five times cheaper than a submerged breakwater for wave heights up to half a metre and, within their limits, become more cost

  20. The Effectiveness, Costs and Coastal Protection Benefits of Natural and Nature-Based Defences

    PubMed Central

    Narayan, Siddharth; Beck, Michael W.; Reguero, Borja G.; Losada, Iñigo J.; van Wesenbeeck, Bregje; Pontee, Nigel; Sanchirico, James N.; Ingram, Jane Carter; Lange, Glenn-Marie; Burks-Copes, Kelly A.

    2016-01-01

    There is great interest in the restoration and conservation of coastal habitats for protection from flooding and erosion. This is evidenced by the growing number of analyses and reviews of the effectiveness of habitats as natural defences and increasing funding world-wide for nature-based defences–i.e. restoration projects aimed at coastal protection; yet, there is no synthetic information on what kinds of projects are effective and cost effective for this purpose. This paper addresses two issues critical for designing restoration projects for coastal protection: (i) a synthesis of the costs and benefits of projects designed for coastal protection (nature-based defences) and (ii) analyses of the effectiveness of coastal habitats (natural defences) in reducing wave heights and the biophysical parameters that influence this effectiveness. We (i) analyse data from sixty-nine field measurements in coastal habitats globally and examine measures of effectiveness of mangroves, salt-marshes, coral reefs and seagrass/kelp beds for wave height reduction; (ii) synthesise the costs and coastal protection benefits of fifty-two nature-based defence projects and; (iii) estimate the benefits of each restoration project by combining information on restoration costs with data from nearby field measurements. The analyses of field measurements show that coastal habitats have significant potential for reducing wave heights that varies by habitat and site. In general, coral reefs and salt-marshes have the highest overall potential. Habitat effectiveness is influenced by: a) the ratios of wave height-to-water depth and habitat width-to-wavelength in coral reefs; and b) the ratio of vegetation height-to-water depth in salt-marshes. The comparison of costs of nature-based defence projects and engineering structures show that salt-marshes and mangroves can be two to five times cheaper than a submerged breakwater for wave heights up to half a metre and, within their limits, become more

  1. "The City Snuffs out Nature": Young People's Conceptions of and Relationship with Nature

    ERIC Educational Resources Information Center

    Pointon, Pam

    2014-01-01

    This paper reports a study of 384 13-14-year olds' written responses to open-ended questions about their understanding of and relationship with "nature." Using constant comparative method the responses were coded, categorised and themed. Most students held scientific conceptions of nature (excluding humans) and a utilitarian relationship…

  2. Commentary: Biochemistry Re-Natured

    ERIC Educational Resources Information Center

    White, Harold B.

    2010-01-01

    In his last commentary on "Biochemistry Denatured," this author dealt with his perception that college students today have spent too little of their childhood years playing outside in nature and as a consequence have not learned basic things about the world from personal experience. This "nature-deficit disorder" removes many opportunities for…

  3. Natural Science Centers: Directory.

    ERIC Educational Resources Information Center

    Natural Science for Youth Foundation, Roswell, GA.

    A nature center is defined as an organized and permanent nonprofit institution which is essentially educational, scientific, and cultural in purpose with professional staff, and open to the public on some regular schedule. A nature center manages and interprets its lands, native plants and animals and facilities to promote an understanding of…

  4. Nature Experience and Education

    ERIC Educational Resources Information Center

    Rathunde, Kevin

    2013-01-01

    Kevin Rathunde turns his research lens to the task of finding out the relevance of the natural world, its impact on adolescent motivation, and its positive sustaining of concentration and focus. He cites "disembodiment and denaturing" as needing to be countered by contact with nature, leading to higher creativity, less drudgery, and more…

  5. Natural Disasters and Nontuberculous Mycobacteria

    PubMed Central

    Bernhard, Jon N.; Chan, Edward D.

    2015-01-01

    Infectious diseases acquired by survivors of large-scale natural disasters complicate the recovery process. During events such as tsunamis, hurricanes, earthquakes, and tornados and well into the recovery period, victims often are exposed to water-soil mixtures that have relocated with indigenous microbes. Because nontuberculous mycobacteria (NTM) are ubiquitous in water and soil, there is potential for increased exposure to these organisms during natural disasters. In this hypothesis-driven commentary, we discuss the rise in NTM lung disease and natural disasters and examine the geographic overlap of NTM infections and disaster frequencies in the United States. Moreover, we show an increased number of positive NTM cultures from Louisiana residents in the years following three of the relatively recent epic hurricanes and posit that such natural disasters may help to drive the increased number of NTM infections. Finally, we advocate for increased environmental studies and surveillance of NTM infections before and after natural disasters. PMID:25644904

  6. Multicellular microorganisms: laboratory versus nature.

    PubMed

    Palková, Zdena

    2004-05-01

    Our present in-depth knowledge of the physiology and regulatory mechanisms of microorganisms has arisen from our ability to remove them from their natural, complex ecosystems into pure liquid cultures. These cultures are grown under optimized laboratory conditions and allow us to study microorganisms as individuals. However, microorganisms naturally grow in conditions that are far from optimal, which causes them to become organized into multicellular communities that are better protected against the harmful environment. Moreover, this multicellular existence allows individual cells to differentiate and acquire specific properties, such as forming resistant spores, which benefit the whole population. The relocation of natural microorganisms to the laboratory can result in their adaptation to these favourable conditions, which is accompanied by complex changes that include the repression of some protective mechanisms that are essential in nature. Laboratory microorganisms that have been cultured for long periods under optimized conditions might therefore differ markedly from those that exist in natural ecosystems.

  7. The Science of Middle Nature (Invited)

    NASA Astrophysics Data System (ADS)

    Pataki, D. E.; Pincetl, S.; Hinners, S.

    2013-12-01

    In the field of biogeochemistry, urbanization is often considered as an 'alteration' or 'disturbance' to the earth's surface and its natural processes. This view is an outcome of the view of nature inherent in earth system science and ecology, in which nature is defined as separate from humans and society. However, other disciplines are based in alternative views of nature in which humans are more integral components of the landscape. Urban planning, landscape architecture, agriculture, and horticulture, for example, more fully integrate the role of landscape design and management in the functioning of human-dominated ecosystems. We suggest that the field of urban biogeochemistry has been somewhat limited by the predominant, disturbance-based view of the role of nature in cities, and that more deeply evaluating and broadening the concept of nature inherent in studies of urban processes can enhance our understanding of the role of urbanization in the earth system. A particularly useful concept is the 'middle nature' proposed by Cosgrove (1993), which serves a purpose of 'actively transforming nature into culture.' It is this view of urban landscapes as middle nature, or transformation of urban space into human-dominated nature with a purpose, that is lacking from the current scientific discourse about the role of biogeochemistry in urban ecosystem services. A scientific evaluation of middle nature implies studying the performance of urban designs to meet intended cultural and environmental goals, including beauty, social equity, governance, and social capital as well as environmental quality. We describe our work in evaluating the transformed urban landscapes of Los Angeles and Salt Lake City from multiple perspectives that focus on urban livability, equity, and beauty as well as the physical impacts of plants and soils on the environment. The outcomes of this process do not necessary meet the traditional demands of biophysical ecology such as utilizing native

  8. Biomimetic syntheses of racemic natural products.

    PubMed

    Zask, Arie; Ellestad, George

    2018-02-01

    Racemic natural products are rarely produced in plants and microorganisms and are thought to be the result of nonenzymatic, spontaneous reactions. These compounds are often highly complex with multiple contiguous chiral centers that present a challenge to organic synthesis. Formation of these racemates often occurs by cyclization reactions that can generate multiple stereocenters from achiral precursors. Biomimetic synthesis of these racemic natural products provides support for their proposed nonenzymatic spontaneous biosynthesis. These elegant syntheses also provide scalable and efficient routes to these complex natural products. Although the number of reported racemic natural products is relatively low, an isolated natural product that has a very small optical rotation has been shown to be a true racemate. Thus, the occurrence of racemic natural products could be more common than thought. © 2017 Wiley Periodicals, Inc.

  9. NCI Program for Natural Product Discovery: A Publicly-Accessible Library of Natural Product Fractions for High-Throughput Screening.

    PubMed

    Thornburg, Christopher C; Britt, John R; Evans, Jason R; Akee, Rhone K; Whitt, James A; Trinh, Spencer K; Harris, Matthew J; Thompson, Jerell R; Ewing, Teresa L; Shipley, Suzanne M; Grothaus, Paul G; Newman, David J; Schneider, Joel P; Grkovic, Tanja; O'Keefe, Barry R

    2018-06-13

    The US National Cancer Institute's (NCI) Natural Product Repository is one of the world's largest, most diverse collections of natural products containing over 230,000 unique extracts derived from plant, marine, and microbial organisms that have been collected from biodiverse regions throughout the world. Importantly, this national resource is available to the research community for the screening of extracts and the isolation of bioactive natural products. However, despite the success of natural products in drug discovery, compatibility issues that make extracts challenging for liquid handling systems, extended timelines that complicate natural product-based drug discovery efforts and the presence of pan-assay interfering compounds have reduced enthusiasm for the high-throughput screening (HTS) of crude natural product extract libraries in targeted assay systems. To address these limitations, the NCI Program for Natural Product Discovery (NPNPD), a newly launched, national program to advance natural product discovery technologies and facilitate the discovery of structurally defined, validated lead molecules ready for translation will create a prefractionated library from over 125,000 natural product extracts with the aim of producing a publicly-accessible, HTS-amenable library of >1,000,000 fractions. This library, representing perhaps the largest accumulation of natural-product based fractions in the world, will be made available free of charge in 384-well plates for screening against all disease states in an effort to reinvigorate natural product-based drug discovery.

  10. Apparatus for dispensing compressed natural gas and liquified natural gas to natural gas powered vehicles

    DOEpatents

    Bingham, Dennis A.; Clark, Michael L.; Wilding, Bruce M.; Palmer, Gary L.

    2007-05-29

    A fueling facility and method for dispensing liquid natural gas (LNG), compressed natural gas (CNG) or both on-demand. The fueling facility may include a source of LNG, such as cryogenic storage vessel. A low volume high pressure pump is coupled to the source of LNG to produce a stream of pressurized LNG. The stream of pressurized LNG may be selectively directed through an LNG flow path or to a CNG flow path which includes a vaporizer configured to produce CNG from the pressurized LNG. A portion of the CNG may be drawn from the CNG flow path and introduced into the CNG flow path to control the temperature of LNG flowing therethrough. Similarly, a portion of the LNG may be drawn from the LNG flow path and introduced into the CNG flow path to control the temperature of CNG flowing therethrough.

  11. Natural Products as Aromatase Inhibitors

    PubMed Central

    Balunas, Marcy J.; Su, Bin; Brueggemeier, Robert W.; Kinghorn, A. Douglas

    2010-01-01

    With the clinical success of several synthetic aromatase inhibitors (AIs) in the treatment of postmenopausal estrogen receptor-positive breast cancer, researchers have also been investigating also the potential of natural products as AIs. Natural products from terrestrial and marine organisms provide a chemically diverse array of compounds not always available through current synthetic chemistry techniques. Natural products that have been used traditionally for nutritional or medicinal purposes (e.g., botanical dietary supplements) may also afford AIs with reduced side effects. A thorough review of the literature regarding natural product extracts and secondary metabolites of plant, microbial, and marine origin that have been shown to exhibit aromatase inhibitory activity is presented herein. PMID:18690828

  12. The Educational Nature of Different Ways Teachers Communicate with Children about Natural Phenomena

    ERIC Educational Resources Information Center

    Gustavsson, Laila; Pramling, Niklas

    2014-01-01

    This empirical study analyses the qualitatively different ways in which teachers approach children's learning in and about nature. The empirical data consists of video observations of children and teachers communicating with one another around natural phenomena found during excursions into a forest. Variation theory is presented as a framework for…

  13. Science Education and the Nature of Nature: Bruno Latour's Ontological Politics

    ERIC Educational Resources Information Center

    Gleason, Tristan

    2017-01-01

    This article explores recent developments in the field of science and technology, and the work of Bruno Latour in particular, to problematize the nature of Nature in science education. Although science and technology studies, and the scholarship on science education alike, have become increasingly attentive to the antidemocratic habits of science…

  14. Birds. Nature Discovery I.

    ERIC Educational Resources Information Center

    Stone, Sally F.

    The birds of New England and their particular habitats are explored in this guide which is part of a series of Nature Discovery publications. The materials are designed to directly supplement the natural science curricula and to complement other subject areas including social studies, language arts, music, and art. The program is designed for…

  15. Introduction to Exploring Nature

    ERIC Educational Resources Information Center

    Early Childhood Today, 2006

    2006-01-01

    Children are fascinated with the world of nature. From the tiniest of seeds to the highest of birds, they wonder "Why?" "How?" and "What can I do with it?" This paper provides intriguing nature activities that provide a solid starting point for expanding children's thinking and learning. Through these activities, children will be building skills…

  16. The 1991 natural gas vehicle challenge: Developing dedicated natural gas vehicle technology

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Larsen, R.; Rimkus, W.; Davies, J.

    An engineering research and design competition to develop and demonstrate dedicated natural gas-powered light-duty trucks, the Natural Gas Vehicle (NGV) Challenge, was held June 6--11, 1191, in Oklahoma. Sponsored by the US Department of Energy (DOE), Energy, Mines, and Resources -- Canada (EMR), the Society of Automative Engineers (SAE), and General Motors Corporation (GM), the competition consisted of rigorous vehicle testing of exhaust emissions, fuel economy, performance parameters, and vehicle design. Using Sierra 2500 pickup trucks donated by GM, 24 teams of college and university engineers from the US and Canada participated in the event. A gasoline-powered control testing asmore » a reference vehicle. This paper discusses the results of the event, summarizes the technologies employed, and makes observations on the state of natural gas vehicle technology.« less

  17. The 1991 natural gas vehicle challenge: Developing dedicated natural gas vehicle technology

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Larsen, R.; Rimkus, W.; Davies, J.

    1992-01-01

    An engineering research and design competition to develop and demonstrate dedicated natural gas-powered light-duty trucks, the Natural Gas Vehicle (NGV) Challenge, was held June 6--11, 1191, in Oklahoma. Sponsored by the US Department of Energy (DOE), Energy, Mines, and Resources -- Canada (EMR), the Society of Automative Engineers (SAE), and General Motors Corporation (GM), the competition consisted of rigorous vehicle testing of exhaust emissions, fuel economy, performance parameters, and vehicle design. Using Sierra 2500 pickup trucks donated by GM, 24 teams of college and university engineers from the US and Canada participated in the event. A gasoline-powered control testing asmore » a reference vehicle. This paper discusses the results of the event, summarizes the technologies employed, and makes observations on the state of natural gas vehicle technology.« less

  18. Constructing Nature with Children: A Phenomenological Study of Preschoolers' Experiences With(in) A Natural Environment

    ERIC Educational Resources Information Center

    Porto, Adonia F.

    2017-01-01

    This research investigated young children's experiences of a natural wetland environment as they constructed meanings of nature in a group. This work was framed theoretically on the premise of social constructivism and ethical listening in efforts to phenomenologically understand how children came to know nature through pre-reflective and…

  19. Method of dehydrating natural gas

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wells, R. E.

    1985-01-01

    A method for dehydration of natural gas is provided wherein well head gas is supplied to a three-phase inlet separator, the vapor mixture of natural gas and water removed from that inlet separator means is supplied to a turboexpander, and the resulting refrigerated mixture of natural gas and condensed water vapor is supplied to a multi-phase outlet separator. The turboexpander may have integral means for subsequent compression of the refrigerated mixture and may be coupled through reduction gears to a means for generating electricity. A portion of the refrigerated mixture may be connected to a heat exchanger for cooling themore » well head natural gas prior to entry into the inlet separator. The flow of refrigerated mixture to this heat exchanger may be controlled by a temperature sensitive valve downstream of the heat exchanger. Methanol may be injected into the vapor mixture prior to entry into the turboexpander. The flow of methanol into the vapor mixture may be controlled by a valve sensitive to the flow rate of the vapor mixture and the water vapor content of the refrigerated mixture. Natural gas vapor from the outlet separator may be recirculated through the turboexpander if the output water vapor content of the natural gas vapor stream is too high.« less

  20. Leluthia astigma (Ashmead)(Hymenoptera: Braconidae: Doryctinae)as a parasitoid of Agrilus planipennis Fairmaire(Coleoptera: Buprestidae: Agrilinae),with assessment of host associations for Nearctic species of Leluthia Cameron

    USDA-ARS?s Scientific Manuscript database

    The validity of host and host plant records are assessed for Leluthia astigma (Ashmead), Leluthia floridensis Marsh, and Leluthia mexicana Cameron, the three known species of Leluthia Cameron in the Nearctic Region. Leluthia astigma is reported from the exotic invasive pest Agrilus planipennis Fairm...

  1. Testing Experimental Compounds against Leishmaniansis in Laboratory Animal Model Systems

    DTIC Science & Technology

    1984-09-01

    1Ox more than that tolerated by patients treated for psychiatric illness (39). In vitro phenazine methosulfate (PMS), reversibly inhibits both -DOand...mexicana amazonensis by phenazine methosulfate. Mol. Biochem. Parasitol. 10: 297-303. 41. Henriksen, T.H. and S. Lende. 1983. Treatment of diffuse cutaneous

  2. Triennial Growth Symposium: Dietary regulation of growth development

    USDA-ARS?s Scientific Manuscript database

    The 2010 Triennial Growth Symposium was held immediately before the Joint Annual Meeting of the American Dairy Science Association, Poultry Science Association, Asociación Mexicana de Producción Animal, Canadian Society of Animal Science, Western Section American Society of Animal Science, and Ameri...

  3. Does Natural Mentoring Matter? A Multilevel Meta-analysis on the Association Between Natural Mentoring and Youth Outcomes.

    PubMed

    Van Dam, L; Smit, D; Wildschut, B; Branje, S J T; Rhodes, J E; Assink, M; Stams, G J J M

    2018-04-25

    In this meta-analytic review, we examined the relation between natural mentoring and youth outcomes in four domains: academic and vocational functioning, social-emotional development, physical health, and psychosocial problems. Natural mentoring relationships are thought to foster positive youth development and buffer against the risks associated with the tumultuous years of adolescence. Two separate meta-analyses were conducted on the presence of a natural mentor and the quality of the natural mentoring relationship, including thirty studies from 1992 to present. The findings indicated that the presence of a natural mentor was significantly associated with positive youth outcomes (r = .106). A larger effect size was found for the quality of the natural mentoring relationship in terms of relatedness, social support, and autonomy support (r = .208). The largest effect sizes were found for social-emotional development and academic and vocational functioning. Risk-status (e.g., teenage mothers, homeless youth, youth in foster care, and youth of alcoholic parents) did not moderate the relation between presence and quality of natural mentoring relationships and youth outcomes, which may indicate that natural mentors are generally beneficial for all youth regardless of risk-status. Implications for theory and practice concerning the quality of the natural mentoring relationship are discussed. © 2018 The Authors. American Journal of Community Psychology published by Wiley Periodicals, Inc. on behalf of Society for Community Research and Action.

  4. Regional and National Use of Semi‐Natural and Natural Depressional Wetlands in Green Infrastructure

    EPA Science Inventory

    Regional and National Use of Semi‐Natural and Natural Depressional Wetlands in Green Infrastructure Charles Lane, US Environmental Protection Agency, Ellen D’Amico, Pegasus Technical ServicesDepressional wetlands are frequently amongst the first aquatic systems to be ...

  5. Mechanisms of children's exposure to nature: Predicting adulthood environmental citizenship and commitment to nature-based activities

    Treesearch

    Stanley T. Asah; David N. Bengston; Lynne M. Westphal; Catherine H. Gowan

    2017-01-01

    Childhood-nature experiences have lifelong effects on environmental citizenship and commitment to nature-based activities. But, it is unclear whether, and to what extent, the different mechanisms through which children and youth experience nature are associated with these outcomes. To test these associations, an online questionnaire assessing mechanisms of childhood...

  6. On Teaching Natural Law.

    ERIC Educational Resources Information Center

    Forte, David F.

    1978-01-01

    A brief look at Columbia, Harvard, and Notre Dame law schools shows that the American tradition in teaching natural law has not been strong. The value of teaching natural law is discussed, a separate course or seminar is seen as the most effective option, and a selection of available sources for such a course is appended. (JMD)

  7. Rhetoric: Its Natural Enemies.

    ERIC Educational Resources Information Center

    Aly, Bower

    1968-01-01

    Every art and discipline must accept competition as a natural condition of life growing from the variant interests and aptitudes of different kinds of men. This competition may lead to the identification of "natural enemies" and, for the discipline of rhetoric, some of these are (1) the business man, who debases rhetoric by using fear and false…

  8. Natural hazards science strategy

    USGS Publications Warehouse

    Holmes, Robert R.; Jones, Lucile M.; Eidenshink, Jeffery C.; Godt, Jonathan W.; Kirby, Stephen H.; Love, Jeffrey J.; Neal, Christina A.; Plant, Nathaniel G.; Plunkett, Michael L.; Weaver, Craig S.; Wein, Anne; Perry, Suzanne C.

    2012-01-01

    The mission of the U.S. Geological Survey (USGS) in natural hazards is to develop and apply hazard science to help protect the safety, security, and economic well-being of the Nation. The costs and consequences of natural hazards can be enormous, and each year more people and infrastructure are at risk. USGS scientific research—founded on detailed observations and improved understanding of the responsible physical processes—can help to understand and reduce natural hazard risks and to make and effectively communicate reliable statements about hazard characteristics, such as frequency, magnitude, extent, onset, consequences, and where possible, the time of future events.To accomplish its broad hazard mission, the USGS maintains an expert workforce of scientists and technicians in the earth sciences, hydrology, biology, geography, social and behavioral sciences, and other fields, and engages cooperatively with numerous agencies, research institutions, and organizations in the public and private sectors, across the Nation and around the world. The scientific expertise required to accomplish the USGS mission in natural hazards includes a wide range of disciplines that this report refers to, in aggregate, as hazard science.In October 2010, the Natural Hazards Science Strategy Planning Team (H–SSPT) was charged with developing a long-term (10-year) Science Strategy for the USGS mission in natural hazards. This report fulfills that charge, with a document hereinafter referred to as the Strategy, to provide scientific observations, analyses, and research that are critical for the Nation to become more resilient to natural hazards. Science provides the information that decisionmakers need to determine whether risk management activities are worthwhile. Moreover, as the agency with the perspective of geologic time, the USGS is uniquely positioned to extend the collective experience of society to prepare for events outside current memory. The USGS has critical statutory

  9. Francis Bacon and the Art-Nature Distinction.

    PubMed

    Weeks, Sophie

    2007-07-01

    Commentators generally expound Bacon's position on the art-nature relationship in terms of how much it retained or departed from traditional conceptions. This paper argues that an appreciation of the Baconian meaning of the terms "art" and "nature" requires a close examination of his wider cosmogonical speculations. Bacon's cosmogonical account moves from a state of unbridled chaos to the relatively stable system for which the term "nature" is normally used. The fundamental principle lying at the heart of Baconian cosmogony is an enriched and appetitive matter: eternal, unchanging, and the plenipotentiary source of all things. Successive limitations of matter's absolute power produced a lazy and habitual nature, which Bacon labelled "nature free." To shift nature from this otiose condition, the Baconian operator recapitulates the original binding of matter. Bacon designated the systematic procedures of binding nature the science of magic. Magic is Bacon's human counterpart to the original cosmogonical process that gave rise to the current system of nature. In Bacon's cosmogony, all possible worlds unfold out of matter: the function of art is to shake out nature's hidden folds. Hence, the distinction between naturalia and artificialia maps on to the distinction between actual and potential. Nature free is without purpose, but art - nature bound - knowingly brings into being an alternative nature designed for human utility.

  10. Central Appalachian basin natural gas database: distribution, composition, and origin of natural gases

    USGS Publications Warehouse

    Román Colón, Yomayra A.; Ruppert, Leslie F.

    2015-01-01

    The U.S. Geological Survey (USGS) has compiled a database consisting of three worksheets of central Appalachian basin natural gas analyses and isotopic compositions from published and unpublished sources of 1,282 gas samples from Kentucky, Maryland, New York, Ohio, Pennsylvania, Tennessee, Virginia, and West Virginia. The database includes field and reservoir names, well and State identification number, selected geologic reservoir properties, and the composition of natural gases (methane; ethane; propane; butane, iso-butane [i-butane]; normal butane [n-butane]; iso-pentane [i-pentane]; normal pentane [n-pentane]; cyclohexane, and hexanes). In the first worksheet, location and American Petroleum Institute (API) numbers from public or published sources are provided for 1,231 of the 1,282 gas samples. A second worksheet of 186 gas samples was compiled from published sources and augmented with public location information and contains carbon, hydrogen, and nitrogen isotopic measurements of natural gas. The third worksheet is a key for all abbreviations in the database. The database can be used to better constrain the stratigraphic distribution, composition, and origin of natural gas in the central Appalachian basin.

  11. Protein space: a natural method for realizing the nature of protein universe.

    PubMed

    Yu, Chenglong; Deng, Mo; Cheng, Shiu-Yuen; Yau, Shek-Chung; He, Rong L; Yau, Stephen S-T

    2013-02-07

    Current methods cannot tell us what the nature of the protein universe is concretely. They are based on different models of amino acid substitution and multiple sequence alignment which is an NP-hard problem and requires manual intervention. Protein structural analysis also gives a direction for mapping the protein universe. Unfortunately, now only a minuscule fraction of proteins' 3-dimensional structures are known. Furthermore, the phylogenetic tree representations are not unique for any existing tree construction methods. Here we develop a novel method to realize the nature of protein universe. We show the protein universe can be realized as a protein space in 60-dimensional Euclidean space using a distance based on a normalized distribution of amino acids. Every protein is in one-to-one correspondence with a point in protein space, where proteins with similar properties stay close together. Thus the distance between two points in protein space represents the biological distance of the corresponding two proteins. We also propose a natural graphical representation for inferring phylogenies. The representation is natural and unique based on the biological distances of proteins in protein space. This will solve the fundamental question of how proteins are distributed in the protein universe. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Contaminant Removal From Natural Resources

    NASA Technical Reports Server (NTRS)

    Clausen, Christian A. (Inventor); Quinn, Jacqueline W. (Inventor); Geiger, Cheri L. (Inventor); Reinhart, Debra (Inventor); Fillpek, Laura B. (Inventor); Coon, Christina (Inventor); Devor, Robert (Inventor)

    2006-01-01

    A zero-valent metal emulsion containing zero-valent metal particles is used to remediate contaminated natural resources, such as groundwater and soil. In a preferred embodiment, the zero-valent metal emulsion removes heavy metals, such as lead (pb), from contaminated natural resources. In another preferred embodiment, the zero-valent metal emulsion is a bimetallic emulsion containing zero-valent metal particles doped with a catalytic metal to remediate halogenated aromatic compounds, such as polychlorinated biphenyls (PCBs), from natural resources.

  13. Natural gas monthly, October 1995

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1995-10-23

    The Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. A glossary of the terms used in this report is provided to assist readers in understanding the data presented in this publication. 6 figs., 30 tabs.

  14. Wind Extraction for Natural Ventilation

    NASA Astrophysics Data System (ADS)

    Fagundes, Tadeu; Yaghoobian, Neda; Kumar, Rajan; Ordonez, Juan

    2017-11-01

    Due to the depletion of energy resources and the environmental impact of pollution and unsustainable energy resources, energy consumption has become one of the main concerns in our rapidly growing world. Natural ventilation, a traditional method to remove anthropogenic and solar heat gains, proved to be a cost-effective, alternative method to mechanical ventilation. However, while natural ventilation is simple in theory, its detailed design can be a challenge, particularly for wind-driven ventilation, which its performance highly involves the buildings' form, surrounding topography, turbulent flow characteristics, and climate. One of the main challenges with wind-driven natural ventilation schemes is due to the turbulent and unpredictable nature of the wind around the building that impose complex pressure loads on the structure. In practice, these challenges have resulted in founding the natural ventilation mainly on buoyancy (rather than the wind), as the primary force. This study is the initial step for investigating the physical principals of wind extraction over building walls and investigating strategies to reduce the dependence of the wind extraction on the incoming flow characteristics and the target building form.

  15. Ethics of respect for nature

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Taylor, P.W.

    The foundational structure for a life-centered theory of environmental ethics consists of three interrelated components. First is the adopting of a certain ultimate moral attitude toward nature, which the author calls respect for nature. Second is a belief system that constitutes a way of conceiving of the natural world and of our place in it. This belief system underlies and supports the attitude in a way that makes it an appropriate attitude to take toward the Earth's natural ecosystems and their life communities. Third is a system of moral rules and standards for guiding our treatment of those ecosystems andmore » life communities, a set of normative principles which give concrete embodiment or expression to the attitude of respect for nature. The theory set forth and defended here is structurally symmetrical with a theory of human ethics based on the principle of respect for persons and the legal entitlement to be protected. We can begin by placing limits on human population and technology.« less

  16. Natural Compounds as Next-Generation Herbicides

    PubMed Central

    Dayan, Franck E.; Duke, Stephen O.

    2014-01-01

    Herbicides with new modes of action (MOAs) are badly needed due to the rapidly evolving resistance to commercial herbicides, but a new MOA has not been introduced in over 20 years. The greatest pest management challenge for organic agriculture is the lack of effective natural product herbicides. The structural diversity and evolved biological activity of natural phytotoxins offer opportunities for the development of both directly used natural compounds and synthetic herbicides with new target sites based on the structures of natural phytotoxins. Natural phytotoxins are also a source for the discovery of new herbicide target sites that can serve as the focus of traditional herbicide discovery efforts. There are many examples of strong natural phytotoxins with MOAs other than those used by commercial herbicides, which indicates that there are molecular targets of herbicides that can be added to the current repertoire of commercial herbicide MOAs. PMID:24784133

  17. The journey of recovery and empowerment embraced by nature - clients' perspectives on nature-based rehabilitation in relation to the role of the natural environment.

    PubMed

    Pálsdóttir, Anna María; Persson, Dennis; Persson, Birgitta; Grahn, Patrik

    2014-07-14

    This paper presents findings from real life situations, a longitudinal single case study on the role of natural environments in nature-based rehabilitation (NBR) for individuals with stress-related mental disorders, at the Alnarp Rehabilitation Garden in Sweden. A sample of 43 former clients voluntarily participated in semi-structured interview, and the data were analyzed according to interpretative phenomenological analysis (IPA). Three main superordinate themes were identified as the three phases of NBR-Prelude, Recuperating and Empowerment-explaining and illuminating the role of the natural environments in each phase. An explanatory model of NBR in this context is presented including the three phases of NBR, IRP supportive occupations and a pyramid of supporting environments. A new component of supportive environments was identified and herby named, Social quietness, an important component facilitating personal and intimate engagement with the natural environments.

  18. Investigating Nature's Mysteries for Drug Development

    Cancer.gov

    More than half of the drugs approved to treat cancer come from a natural product or a natural product prototype. Scientists in NCI-Frederick's Natural Products Branch are exploring ways to harness chemicals produced by marine invertebrates, other animals, plants, and microbes for cancer drug discovery.

  19. Nature of Science or Nature of the Sciences?

    ERIC Educational Resources Information Center

    Schizas, Dimitrios; Psillos, Dimitris; Stamou, George

    2016-01-01

    The present essay examines the emerging issue of domain-general versus domain-specific nature of science (NOS) understandings from a perspective that illuminates the value of domain-specific philosophies of science for the growth and development of the NOS educational field. Under the assumption that individual sciences do have their own…

  20. Natural compounds as next-generation herbicides.

    PubMed

    Dayan, Franck E; Duke, Stephen O

    2014-11-01

    Herbicides with new modes of action (MOAs) are badly needed due to the rapidly evolving resistance to commercial herbicides, but a new MOA has not been introduced in over 20 years. The greatest pest management challenge for organic agriculture is the lack of effective natural product herbicides. The structural diversity and evolved biological activity of natural phytotoxins offer opportunities for the development of both directly used natural compounds and synthetic herbicides with new target sites based on the structures of natural phytotoxins. Natural phytotoxins are also a source for the discovery of new herbicide target sites that can serve as the focus of traditional herbicide discovery efforts. There are many examples of strong natural phytotoxins with MOAs other than those used by commercial herbicides, which indicates that there are molecular targets of herbicides that can be added to the current repertoire of commercial herbicide MOAs. © 2014 American Society of Plant Biologists. All Rights Reserved.

  1. Characteristics of muscle dysmorphia in male football, weight training, and competitive natural and non-natural bodybuilding samples.

    PubMed

    Baghurst, Timothy; Lirgg, Cathy

    2009-06-01

    The purpose of this study was to identify differences in traits associated with muscle dysmorphia between collegiate football players (n=66), weight trainers for physique (n=115), competitive non-natural bodybuilders (n=47), and competitive natural bodybuilders (n=65). All participants completed demographic questionnaires in addition to the Muscle Dysmorphia Inventory (Rhea, Lantz, & Cornelius, 2004). Results revealed a significant main effect for group, and post hoc tests found that the non-natural bodybuilding group did not score significantly higher than the natural bodybuilding group on any subscale except for Pharmacological Use. Both the non-natural and natural bodybuilding groups scored significantly higher than those that weight trained for physique on the Dietary Behavior and Supplement Use subscales. The collegiate football players scored lowest on all subscales of the Muscle Dysmorphia Inventory except for Physique Protection where they scored highest. Findings are discussed with future research expounded.

  2. Testing Experimental Compounds against American Cutaneous and Mucocutaneous Leishmaniasis

    DTIC Science & Technology

    1982-06-01

    synthesize large amounts of plasma membrane ergosterol in serum-free media (26). Ketoconazole and miconazole actively disrupt ergosterol synthesis in a...walls cross- * react with L. donovani (40), it was thought that immunostimula- tion of a htst with BCG prior to infection with L. mexicana ama- zonensis

  3. 31 CFR 540.309 - Natural uranium.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Natural uranium. 540.309 Section 540... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.309 Natural uranium. The term natural uranium means uranium found in...

  4. 31 CFR 540.309 - Natural uranium.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Natural uranium. 540.309 Section 540... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.309 Natural uranium. The term natural uranium means uranium found in...

  5. 31 CFR 540.309 - Natural uranium.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Natural uranium. 540.309 Section 540... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.309 Natural uranium. The term natural uranium means uranium found in...

  6. 34 CFR 303.26 - Natural environments.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 2 2013-07-01 2013-07-01 false Natural environments. 303.26 Section 303.26 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND... DISABILITIES General Definitions Used in This Part § 303.26 Natural environments. Natural environments means...

  7. 34 CFR 303.26 - Natural environments.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 2 2012-07-01 2012-07-01 false Natural environments. 303.26 Section 303.26 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND... DISABILITIES General Definitions Used in This Part § 303.26 Natural environments. Natural environments means...

  8. 34 CFR 303.26 - Natural environments.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 2 2014-07-01 2013-07-01 true Natural environments. 303.26 Section 303.26 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND... DISABILITIES General Definitions Used in This Part § 303.26 Natural environments. Natural environments means...

  9. Nature Guidance and Guidance in Friluftsliv.

    ERIC Educational Resources Information Center

    Ulstrup, Svend

    2001-01-01

    Although Danish nature guides conduct outdoor biology classes and friluftsliv (open-air life) guides teach enjoyment of nature, cooperation is nonexistent. Danish students and schools are enthusiastic about friluftsliv, but authorities obstruct participation. Mass media depict nature as a challenge course for pleasure instead of a basis for…

  10. 31 CFR 540.309 - Natural uranium.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Natural uranium. 540.309 Section 540.309 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... REGULATIONS General Definitions § 540.309 Natural uranium. The term natural uranium means uranium found in...

  11. 31 CFR 540.309 - Natural uranium.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Natural uranium. 540.309 Section 540.309 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... REGULATIONS General Definitions § 540.309 Natural uranium. The term natural uranium means uranium found in...

  12. Airborne allergenic pollen in natural areas: Hornachuelos Natural Park, Cordoba, southern Spain.

    PubMed

    Garcia-Mozo, Herminia; Dominguez-Vilches, Eugenio; Galan, Carmen

    2007-01-01

    The present study shows the results of monitoring the atmospheric pollen in the atmosphere of an area of natural vegetation, the Hornachuelos Natural Park, Cordoba, southern Spain, during a six years (1998-2003). Special attention was paid in the seasonal and intra-diurnal characteristics of airborne allergenic pollen. During this period, 31 pollen types were described, some of them rare in aerobiological analysis. High concentrations of allergenic pollen from entomophilous species and from areas at a long distance were found. Significant differences between pollen spectrum and pollen concentration of the natural study area and the surrounding cities were detected. Intra-diurnal pattern from trees surrounding the trap presented a clear peak at midday/afternoon. Pollen from taxa comprising many species and from species at far locations showed a smoother intra-diurnal pattern. The correlation with meteorological parameters was positive with maximum and mean temperatures, and negative with humidity and rainfall.

  13. 36 CFR 62.7 - Natural landmark modifications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Natural landmark... INTERIOR NATIONAL NATURAL LANDMARKS PROGRAM § 62.7 Natural landmark modifications. (a) Determination of need for modifications. After designation, the modification of the boundaries of a natural landmark...

  14. 36 CFR 62.7 - Natural landmark modifications.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Natural landmark... INTERIOR NATIONAL NATURAL LANDMARKS PROGRAM § 62.7 Natural landmark modifications. (a) Determination of need for modifications. After designation, the modification of the boundaries of a natural landmark...

  15. Natural Resource Damages: A Primer

    EPA Pesticide Factsheets

    define concepts, terms and discuss topics related to NRD activities such as the authority under which NRD are assessed; definition; role of EPA; designation of Natural Resource Trustees; and conduct of natural resource assessments and restorations.

  16. [Standardized investigation on medicinal nature of ethnomedicine].

    PubMed

    Li, Zhi-Yong; Yang, Yong-Qiang; Li, Lin-Sen; Li, Yan-Wen; Lin, Ling; Cheng, Yang-Yang

    2016-06-01

    This article recorded the analysis and comparison between the medicinal nature theory of traditional Chinese medicine(TCM) and ethnomedicine(EM). The vocabulary of "medicinal nature" was suggested to indicate the properties of ethnomedicine. Based on the influence of TCM medicinal nature theory on EM in China, the application of medicinal nature theory in EM was divided into 3 classes, and the standardizing principles for EM medicinal nature were proposed. It was suggested that medicinal quality, flavor, tendency, tropism, degree and efficiency can be used for the classification standard for EM medicinal nature. Copyright© by the Chinese Pharmaceutical Association.

  17. Geographic Distribution of Leishmania Species in Ecuador Based on the Cytochrome B Gene Sequence Analysis

    PubMed Central

    Kato, Hirotomo; Gomez, Eduardo A.; Martini-Robles, Luiggi; Muzzio, Jenny; Velez, Lenin; Calvopiña, Manuel; Romero-Alvarez, Daniel; Mimori, Tatsuyuki; Uezato, Hiroshi; Hashiguchi, Yoshihisa

    2016-01-01

    A countrywide epidemiological study was performed to elucidate the current geographic distribution of causative species of cutaneous leishmaniasis (CL) in Ecuador by using FTA card-spotted samples and smear slides as DNA sources. Putative Leishmania in 165 samples collected from patients with CL in 16 provinces of Ecuador were examined at the species level based on the cytochrome b gene sequence analysis. Of these, 125 samples were successfully identified as Leishmania (Viannia) guyanensis, L. (V.) braziliensis, L. (V.) naiffi, L. (V.) lainsoni, and L. (Leishmania) mexicana. Two dominant species, L. (V.) guyanensis and L. (V.) braziliensis, were widely distributed in Pacific coast subtropical and Amazonian tropical areas, respectively. Recently reported L. (V.) naiffi and L. (V.) lainsoni were identified in Amazonian areas, and L. (L.) mexicana was identified in an Andean highland area. Importantly, the present study demonstrated that cases of L. (V.) braziliensis infection are increasing in Pacific coast areas. PMID:27410039

  18. Leishmania species identification using FTA card sampling directly from patients' cutaneous lesions in the state of Lara, Venezuela.

    PubMed

    Kato, Hirotomo; Watanabe, Junko; Mendoza Nieto, Iraida; Korenaga, Masataka; Hashiguchi, Yoshihisa

    2011-10-01

    A molecular epidemiological study was performed using FTA card materials directly sampled from lesions of patients with cutaneous leishmaniasis (CL) in the state of Lara, Venezuela, where causative agents have been identified as Leishmania (Viannia) braziliensis and L. (Leishmania) venezuelensis in previous studies. Of the 17 patients diagnosed with CL, Leishmania spp. were successfully identified in 16 patients based on analysis of the cytochrome b gene and rRNA internal transcribed spacer sequences. Consistent with previous findings, seven of the patients were infected with L. (V.) braziliensis. However, parasites from the other nine patients were genetically identified as L. (L.) mexicana, which differed from results of previous enzymatic and antigenic analyses. These results strongly suggest that L. (L.) venezuelensis is a variant of L. (L.) mexicana and that the classification of L. (L.) venezuelensis should be reconsidered. Copyright © 2011 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

  19. Uranium, natural

    Integrated Risk Information System (IRIS)

    Uranium , natural ; CASRN 7440 - 61 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  20. 36 CFR 62.6 - Natural landmark monitoring.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Natural landmark monitoring... INTERIOR NATIONAL NATURAL LANDMARKS PROGRAM § 62.6 Natural landmark monitoring. (a) Owner contact. The Field Offices of the NPS maintain periodic contacts with the owners of designated national natural...

  1. Nature and the natural environment as health facilitators: the need to reconceptualize the ICF environmental factors.

    PubMed

    Day, Adam M B; Theurer, Julie A; Dykstra, Allyson D; Doyle, Philip C

    2012-01-01

    This work examines the environmental factors component of the International Classification of Functioning, Disability, and Health (ICF) relative to current health-facilitating evidence about natural environmental factors. We argue that the environmental factors component warrants reconceptualization in order to offer an extended and more systematic framework for identifying and measuring health-facilitating natural environmental factors. Current evidence highlighting the potential health-facilitating benefits of natural environmental factors is synthesized and considered in the context of the ICF framework and its coding system. In its current form, the ICF's conceptual framework and coding system are inadequate for identifying and measuring natural environmental factors in individuals and groups with and/or without health conditions. The ICF provides an advanced framework for health and disability that reflects contemporary conceptualizations about health. However, given the scope of emerging evidence highlighting positive health and well-being outcomes associated with natural environmental factors, we believe the environmental factors component requires further advancement to reflect this current knowledge. Reconceptualizing the environmental factors component supports a more holistic interpretation of the continuum of environmental factors as both facilitators and barriers. In doing so, it strengthens the ICF's utility in identifying and measuring health-facilitating natural environmental factors.

  2. A Grab Bag of Nature Activities.

    ERIC Educational Resources Information Center

    Miller, Lenore

    1993-01-01

    Suggested nature activities include (1) sensory experiences to distinguish all characteristics of various objects; (2) adopt-a-tree activities where children learn about "their own" tree; (3) finding evidence of animals in nature; (4) nature questions of the week with prizes for correct answers; and (5) activities related to the…

  3. A Simple Lesson in Experiencing Nature.

    ERIC Educational Resources Information Center

    Simpson, Steven

    1999-01-01

    Experiential education considers nature a classroom, but nature is also the teacher. Quiet watching and walking meditation are two exercises informed by Taoism, that when added to the normal experiential education fare, help students encounter nature with an open mind. An outdoor university course that incorporates the sentiments of seeing nature…

  4. Thermodynamic DFT analysis of natural gas.

    PubMed

    Neto, Abel F G; Huda, Muhammad N; Marques, Francisco C; Borges, Rosivaldo S; Neto, Antonio M J C

    2017-08-01

    Density functional theory was performed for thermodynamic predictions on natural gas, whose B3LYP/6-311++G(d,p), B3LYP/6-31+G(d), CBS-QB3, G3, and G4 methods were applied. Additionally, we carried out thermodynamic predictions using G3/G4 averaged. The calculations were performed for each major component of seven kinds of natural gas and to their respective air + natural gas mixtures at a thermal equilibrium between room temperature and the initial temperature of a combustion chamber during the injection stage. The following thermodynamic properties were obtained: internal energy, enthalpy, Gibbs free energy and entropy, which enabled us to investigate the thermal resistance of fuels. Also, we estimated an important parameter, namely, the specific heat ratio of each natural gas; this allowed us to compare the results with the empirical functions of these parameters, where the B3LYP/6-311++G(d,p) and G3/G4 methods showed better agreements. In addition, relevant information on the thermal and mechanic resistance of natural gases were investigated, as well as the standard thermodynamic properties for the combustion of natural gas. Thus, we show that density functional theory can be useful for predicting the thermodynamic properties of natural gas, enabling the production of more efficient compositions for the investigated fuels. Graphical abstract Investigation of the thermodynamic properties of natural gas through the canonical ensemble model and the density functional theory.

  5. A restatement of the natural science evidence concerning catchment-based `natural' flood management in the UK

    NASA Astrophysics Data System (ADS)

    Dadson, Simon J.; Hall, Jim W.; Murgatroyd, Anna; Acreman, Mike; Bates, Paul; Beven, Keith; Heathwaite, Louise; Holden, Joseph; Holman, Ian P.; Lane, Stuart N.; O'Connell, Enda; Penning-Rowsell, Edmund; Reynard, Nick; Sear, David; Thorne, Colin; Wilby, Rob

    2017-03-01

    Flooding is a very costly natural hazard in the UK and is expected to increase further under future climate change scenarios. Flood defences are commonly deployed to protect communities and property from flooding, but in recent years flood management policy has looked towards solutions that seek to mitigate flood risk at flood-prone sites through targeted interventions throughout the catchment, sometimes using techniques which involve working with natural processes. This paper describes a project to provide a succinct summary of the natural science evidence base concerning the effectiveness of catchment-based `natural' flood management in the UK. The evidence summary is designed to be read by an informed but not technically specialist audience. Each evidence statement is placed into one of four categories describing the nature of the underlying information. The evidence summary forms the appendix to this paper and an annotated bibliography is provided in the electronic supplementary material.

  6. A restatement of the natural science evidence concerning catchment-based 'natural' flood management in the UK.

    PubMed

    Dadson, Simon J; Hall, Jim W; Murgatroyd, Anna; Acreman, Mike; Bates, Paul; Beven, Keith; Heathwaite, Louise; Holden, Joseph; Holman, Ian P; Lane, Stuart N; O'Connell, Enda; Penning-Rowsell, Edmund; Reynard, Nick; Sear, David; Thorne, Colin; Wilby, Rob

    2017-03-01

    Flooding is a very costly natural hazard in the UK and is expected to increase further under future climate change scenarios. Flood defences are commonly deployed to protect communities and property from flooding, but in recent years flood management policy has looked towards solutions that seek to mitigate flood risk at flood-prone sites through targeted interventions throughout the catchment, sometimes using techniques which involve working with natural processes. This paper describes a project to provide a succinct summary of the natural science evidence base concerning the effectiveness of catchment-based 'natural' flood management in the UK. The evidence summary is designed to be read by an informed but not technically specialist audience. Each evidence statement is placed into one of four categories describing the nature of the underlying information. The evidence summary forms the appendix to this paper and an annotated bibliography is provided in the electronic supplementary material.

  7. Natural pigments and sacred art

    NASA Astrophysics Data System (ADS)

    Kelekian, Lena, ,, Lady

    2010-05-01

    Since the dawn of mankind, cavemen has expressed himself through art. The earliest known cave paintings date to some 32,000 years ago and used 4 colours derived from the earth. These pigments were iron oxides and known as ochres, blacks and whites. All pigments known by the Egyptians, the Greeks, the Romans and Renaissance man were natural and it was not until the 18th century that synthetic pigments were made and widely used. Until that time all art, be it sacred or secular used only natural pigments, of which the preparation of many have been lost or rarely used because of their tedious preparation. As a geologist, a mineralogist and an artist specializing in iconography, I have been able to rediscover 89 natural pigments extracted from minerals. I use these pigments to paint my icons in the traditional Byzantine manner and also to restore old icons, bringing back their glamour and conserving them for years to come. The use of the natural pigments in its proper way also helps to preserve the traditional skills of the iconographer. In the ancient past, pigments were extremely precious. Many took an exceedingly long journey to reach the artists, and came from remote countries. Research into these pigments is the work of history, geography and anthropology. It is an interesting journey in itself to discover that the blue aquamarines came from Afghanistan, the reds from Spain, the greens Africa, and so on. In this contribution I will be describing the origins, preparation and use of some natural pigments, together with their history and provenance. Additionally, I will show how the natural pigments are used in the creation of an icon. Being a geologist iconographer, for me, is a sacrement that transforms that which is earthly, material and natural into a thing of beauty that is sacred. As bread and wine in the Eucharist, water during baptism and oil in Holy Union transmit sanctification to the beholder, natural pigments do the same when one considers an icon. The

  8. Natural selection promotes antigenic evolvability.

    PubMed

    Graves, Christopher J; Ros, Vera I D; Stevenson, Brian; Sniegowski, Paul D; Brisson, Dustin

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed 'cassettes' that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios) and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish chronic infections.

  9. Natural Selection Promotes Antigenic Evolvability

    PubMed Central

    Graves, Christopher J.; Ros, Vera I. D.; Stevenson, Brian; Sniegowski, Paul D.; Brisson, Dustin

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed ‘cassettes’ that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios) and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish chronic infections

  10. Review of natural fiber composites

    NASA Astrophysics Data System (ADS)

    Rohan, T.; Tushar, B.; T, Mahesha G.

    2018-02-01

    Development of new alternative materials to the existing traditional metals, alloys and synthetic materials is the new buzz in recent research activities at the academic and industrial level taking place all over the world. Earning carbon credits by minimizing the atmospheric pollution is getting an increase in attention by industries. One small step to conserve the atmosphere around us is to use natural resources in making fully bio degradable or partially bio degradable composite materials. Such prepared alternative materials can find applications in interior housing, automotive, marine, domestic, and other applications. Composites made by using appropriate natural fibers as reinforcements is a possibility that ensures such a reality as they can be well received in multiple disciplines of engineering. Results published from various research activities illustrates that natural fiber composites can successfully be adapted for non-structural, moderate load bearing indoor applications. Further, the few deficiencies in the natural fibers can be overcome by subjecting them to morphological changes by various physical or chemical treatment methods. The overall objective of this paper is to provide a comprehensive overview of the property profiles of Natural Fiber Composites.

  11. 7 CFR 2900.4 - Natural gas requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Natural gas requirements. 2900.4 Section 2900.4..., DEPARTMENT OF AGRICULTURE ESSENTIAL AGRICULTURAL USES AND VOLUMETRIC REQUIREMENTS-NATURAL GAS POLICY ACT § 2900.4 Natural gas requirements. For purposes of Section 401(c), NGPA, the natural gas requirements for...

  12. 7 CFR 2900.4 - Natural gas requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 15 2011-01-01 2011-01-01 false Natural gas requirements. 2900.4 Section 2900.4..., DEPARTMENT OF AGRICULTURE ESSENTIAL AGRICULTURAL USES AND VOLUMETRIC REQUIREMENTS-NATURAL GAS POLICY ACT § 2900.4 Natural gas requirements. For purposes of Section 401(c), NGPA, the natural gas requirements for...

  13. Natural Underwater Adhesives

    PubMed Central

    Stewart, Russell J.; Ransom, Todd C.; Hlady, Vladimir

    2011-01-01

    The general topic of this review is protein-based underwater adhesives produced by aquatic organisms. The focus is on mechanisms of interfacial adhesion to native surfaces and controlled underwater solidification of natural water-borne adhesives. Four genera that exemplify the broad range of function, general mechanistic features, and unique adaptations are discussed in detail: blue mussels, acorn barnacles, sandcastle worms, and freshwater caddisfly larva. Aquatic surfaces in nature are charged and in equilibrium with their environment, populated by an electrical double layer of ions as well as adsorbed natural polyelectrolytes and microbial biofilms. Surface adsorption of underwater bioadhesives likely occurs by exchange of surface bound ligands by amino acid sidechains, driven primarily by relative affinities and effective concentrations of polymeric functional groups. Most aquatic organisms exploit modified amino acid sidechains, in particular phosphorylated serines and hydroxylated tyrosines (dopa), with high-surface affinity that form coordinative surface complexes. After delivery to the surfaces as a fluid, permanent natural adhesives solidify to bear sustained loads. Mussel plaques are assembled in a manner superficially reminiscent of in vitro layer-by-layer strategies, with sequentially delivered layers associated through Fe(dopa)3 coordination bonds. The adhesives of sandcastle worms, caddisfly larva, and barnacles may be delivered in a form somewhat similar to in vitro complex coacervation. Marine adhesives are secreted, or excreted, into seawater that has a significantly higher pH and ionic strength than the internal environment. Empirical evidence suggests these environment triggers could provide minimalistic, fail-safe timing mechanisms to prevent premature solidification (insolubilization) of the glue within the secretory system, yet allow rapid solidification after secretion. Underwater bioadhesives are further strengthened by secondary covalent

  14. 40 CFR 1065.715 - Natural gas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Natural gas. 1065.715 Section 1065.715... PROCEDURES Engine Fluids, Test Fuels, Analytical Gases and Other Calibration Standards § 1065.715 Natural gas. (a) Except as specified in paragraph (b) of this section, natural gas for testing must meet the...

  15. [Heart transplantation for the treatment of isolated left ventricular myocardial noncompaction. First case in Mexico].

    PubMed

    Zetina-Tun, Hugo Jesús; Careaga-Reyna, Guillermo; Galván-Díaz, José; Sánchez-Uribe, Magdalena

    Myocardial noncompaction of the left ventricle is a congenital cardiomyopathy characterised by left ventricular hypertrabeculation and prominent intertrabecular recesses. The incidence ranges from 0.15% to 2.2%. Clinical manifestations include heart failure, arrhythmias, and stroke. Prognosis is fatal in most cases. Heart transplantation is a therapeutic option for this cardiomyopathy, and few had been made worldwide. The case is presented of a 20 year-old male with noncompacted myocardium of the left ventricle, who had clinical signs of heart failure. His functional class was IV on the New York Heart Association scale. He was successfully transplanted. Its survival to 15 months is optimal in class I New York Heart Association, and endomyocardial biopsies have been reported without evidence of acute rejection. It is concluded that heart transplantation modified the natural history and improved survival in patients with this congenital heart disease. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  16. Natural environment analysis

    NASA Technical Reports Server (NTRS)

    Frost, W.

    1985-01-01

    The influence of terrain features on wind loading of the space shuttle while on the launch pad, or during early liftoff, was investigated both qualitatively and quantitatively. The climatology and meteorology producing macroscale wind patterns and characteristics for the Vandenburg Air Force Base launch site are described. Field test data are analyzed, and the nature and characteristic of flow disturbances due to the various terrain features, both natural and man-made, are reviewed. The magnitude of these wind loads are estimated. Finally, effects of turbulence are discussed. It is concluded that the influence of complex terrain can create significant wind loading on the vehicle.

  17. Construction of a 3D-shaped, natural product like fragment library by fragmentation and diversification of natural products.

    PubMed

    Prescher, Horst; Koch, Guido; Schuhmann, Tim; Ertl, Peter; Bussenault, Alex; Glick, Meir; Dix, Ina; Petersen, Frank; Lizos, Dimitrios E

    2017-02-01

    A fragment library consisting of 3D-shaped, natural product-like fragments was assembled. Library construction was mainly performed by natural product degradation and natural product diversification reactions and was complemented by the identification of 3D-shaped, natural product like fragments available from commercial sources. In addition, during the course of these studies, novel rearrangements were discovered for Massarigenin C and Cytochalasin E. The obtained fragment library has an excellent 3D-shape and natural product likeness, covering a novel, unexplored and underrepresented chemical space in fragment based drug discovery (FBDD). Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. 21 CFR 582.30 - Natural substances used in conjunction with spices and other natural seasonings and flavorings.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Natural substances used in conjunction with spices and other natural seasonings and flavorings. 582.30 Section 582.30 Food and Drugs FOOD AND DRUG... SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Provisions § 582.30 Natural substances used in conjunction...

  19. Prevalencia de síntomas depresivos e invarianza factorial de la Escala de Depresión del Centro de Estudios Epidemiológicos (CES-D) en población indígena mexicana.

    PubMed

    Franco-Díaz, Karen Lizbeth; Fernández-Niño, Julián Alfredo; Astudillo-García, Claudia Iveth

    2018-05-01

    Introducción. La versión breve de la Escala de Depresión del Centro de Estudios Epidemiológicos (CESD) es un recurso factible para la tamización de los síntomas de depresión en la población general, pero no se ha reportado la prevalencia en la población indígena, ni su invarianza factorial en Latinoamérica.Objetivo. Describir la prevalencia de los síntomas de depresión y la invarianza factorial de la versión breve de la escala CES-D en población indígena mexicana.Materiales y métodos. Se hizo un estudio transversal en una muestra representativa de 37.165 adultos mexicanos de 20 a 59 años de edad. La identidad indígena se determinó mediante el propio reporte de la persona como hablante de una lengua indígena. Se conformaron ocho grupos de análisis según el sexo, el alfabetismo y el ser indígena. Se describió la prevalencia de los síntomas depresivos en cada grupo, así como la invarianza factorial de la configuración de los perfiles mediante un análisis factorial exploratorio. Las matrices de varianza y covarianza se compararon entre pares de perfiles usando el test modificado de Mantel.Resultados. La prevalencia de síntomas depresivos en mujeres indígenas que sabían leer fue de 16,8 % (IC95%: 13,4-20,3); en mujeres indígenas que no sabían leer, de 21,3 % (IC95%: 15,5-27,1); en hombres indígenas que sabían leer de 8,5 % (IC95%: 6,0-11,1), y en hombres indígenas que no sabían leer de 10,4 % (IC95%: 5,2-15,6). No se encontraron diferencias significativas en las cargas factoriales entre los perfiles.Conclusión. Se reportó una menor prevalencia de síntomas depresivos en indígenas que en la población no indígena. La escala CES-D en su versión breve mostró invarianza factorial al emplearla en la población indígena.

  20. Restorative effects of virtual nature settings.

    PubMed

    Valtchanov, Deltcho; Barton, Kevin R; Ellard, Colin

    2010-10-01

    Previous research regarding the potential benefits of exposing individuals to surrogate nature (photographs and videos) has found that such immersion results in restorative effects such as increased positive affect, decreased negative affect, and decreased stress. In the current experiment, we examined whether immersion in a virtual computer-generated nature setting could produce restorative effects. Twenty-two participants were equally divided between two conditions, while controlling for gender. In each condition, participants performed a stress-induction task, and were then immersed in virtual reality (VR) for 10 minutes. The control condition featured a slide show in VR, and the nature experimental condition featured an active exploration of a virtual forest. Participants in the nature condition were found to exhibit increased positive affect and decreased stress after immersion in VR when compared to those in the control condition. The results suggest that immersion in virtual nature settings has similar beneficial effects as exposure to surrogate nature. These results also suggest that VR can be used as a tool to study and understand restorative effects.

  1. Alternative Fuels Data Center: Natural Gas Benefits

    Science.gov Websites

    Benefits to someone by E-mail Share Alternative Fuels Data Center: Natural Gas Benefits on Facebook Tweet about Alternative Fuels Data Center: Natural Gas Benefits on Twitter Bookmark Alternative Fuels Data Center: Natural Gas Benefits on Google Bookmark Alternative Fuels Data Center: Natural Gas

  2. Alternative Fuels Data Center: Natural Gas Production

    Science.gov Websites

    Production to someone by E-mail Share Alternative Fuels Data Center: Natural Gas Production on Facebook Tweet about Alternative Fuels Data Center: Natural Gas Production on Twitter Bookmark Alternative Fuels Data Center: Natural Gas Production on Google Bookmark Alternative Fuels Data Center: Natural Gas

  3. Natural fracture systems studies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lorenz, J.C.; Warpinski, N.R.

    The objectives of this program are (1) to develop a basinal-analysis methodology for natural fracture exploration and exploitation, and (2) to determine the important characteristics of natural fracture systems for use in completion, stimulation, and production operations. Natural-fracture basinal analysis begins with studies of fractures in outcrop, core and logs in order to determine the type of fracturing and the relationship of the fractures to the lithologic environment. Of particular interest are the regional fracture systems that are pervasive in western US tight sand basins. A Methodology for applying this analysis is being developed, with the goal of providing amore » structure for rationally characterizing natural fracture systems basin-wide. Such basin-wide characterizations can then be expanded and supplemented locally, at sites where production may be favorable. Initial application of this analysis is to the Piceance basin where there is a wealth of data from the Multiwell Experiment (MWX), DOE cooperative wells, and other basin studies conducted by Sandia, CER Corporation, and the USGS (Lorenz and Finley, 1989, Lorenz et aI., 1989, and Spencer and Keighin, 1984). Such a basinal approach has been capable of explaining the fracture characteristics found throughout the southern part of the Piceance basin and along the Grand Hogback.« less

  4. A Nature Center for Your Community.

    ERIC Educational Resources Information Center

    Shomon, Joseph J.

    A nature center is an outdoor education area; a parcel of natural land where people, particularly the young, and nature can meet. It can be an educational section of a state or national forest or park set aside specifically to serve the people of one or several nearby communities. These centers usually include an educational or interpretive…

  5. Natural Disasters: Earth Science Readings. Reproducibles.

    ERIC Educational Resources Information Center

    Lobb, Nancy

    Natural Disasters is a reproducible teacher book that explains what scientists believe to be the causes of a variety of natural disasters and suggests steps that teachers and students can take to be better prepared in the event of a natural disaster. It contains both student and teacher sections. Teacher sections include vocabulary, an answer key,…

  6. Natural disasters and suicide: evidence from Japan.

    PubMed

    Matsubayashi, Tetsuya; Sawada, Yasuyuki; Ueda, Michiko

    2013-04-01

    Previous research shows no consensus as to whether and how natural disasters affect suicide rates in their aftermath. Using prefecture-level panel data of natural disasters and suicide in Japan between 1982 and 2010, we estimate both contemporaneous and lagged effects of natural disasters on the suicide rates of various demographic groups. We find that when the damage caused by natural disasters is extremely large, as in the case of the Great Hanshin-Awaji Earthquake in 1995, suicide rates tend to increase in the immediate aftermath of the disaster and several years later. However, when the damage by natural disasters is less severe, suicide rates tend to decrease after the disasters, especially one or two years later. Thus, natural disasters affect the suicide rates of affected populations in a complicated way, depending on the severity of damages as well as on how many years have passed since the disaster. We also find that the effects of natural disasters on suicide rates vary considerably across demographic groups, which suggests that some population subgroups are more vulnerable to the impact of natural disasters than others. We then test the possibility that natural disasters enhance people's willingness to help others in society, an effect that may work as a protective factor against disaster victims' suicidal risks. We find that natural disasters increase the level of social ties in affected communities, which may mitigate some of the adverse consequence of natural disasters, resulting in a decline in suicide rates. Our findings also indicate that when natural disasters are highly destructive and disruptive, such protective features of social connectedness are unlikely to be enough to compensate for the severe negative impact of disasters on health outcomes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. North American Natural Gas Vision

    DTIC Science & Technology

    2005-01-01

    hand sales of natural gas and LPG. 17 Decreto Legal, Diario Oficial , Noviembre 25, 1993. 37 Review Section 38 Figure 2. Mexican Natural Gas...California 500 Mexicali Baja California 29 Naco - Hermosillo Sonora 130 Nacozari de Garcia Sonora 85 Agua Prieta Sonora 173

  8. Natural thermodynamics

    NASA Astrophysics Data System (ADS)

    Annila, Arto

    2016-02-01

    The principle of increasing entropy is derived from statistical physics of open systems assuming that quanta of actions, as undividable basic build blocks, embody everything. According to this tenet, all systems evolve from one state to another either by acquiring quanta from their surroundings or by discarding quanta to the surroundings in order to attain energetic balance in least time. These natural processes result in ubiquitous scale-free patterns: skewed distributions that accumulate in a sigmoid manner and hence span log-log scales mostly as straight lines. Moreover, the equation for least-time motions reveals that evolution is by nature a non-deterministic process. Although the obtained insight in thermodynamics from the notion of quanta in motion yields nothing new, it accentuates that contemporary comprehension is impaired when modeling evolution as a computable process by imposing conservation of energy and thereby ignoring that quantum of actions are the carriers of energy from the system to its surroundings.

  9. Inequality in nature and society

    PubMed Central

    Scheffer, Marten; van Bavel, Bas; van de Leemput, Ingrid A.; van Nes, Egbert H.

    2017-01-01

    Most societies are economically dominated by a small elite, and similarly, natural communities are typically dominated by a small fraction of the species. Here we reveal a strong similarity between patterns of inequality in nature and society, hinting at fundamental unifying mechanisms. We show that chance alone will drive 1% or less of the community to dominate 50% of all resources in situations where gains and losses are multiplicative, as in returns on assets or growth rates of populations. Key mechanisms that counteract such hyperdominance include natural enemies in nature and wealth-equalizing institutions in society. However, historical research of European developments over the past millennium suggests that such institutions become ineffective in times of societal upscaling. A corollary is that in a globalizing world, wealth will inevitably be appropriated by a very small fraction of the population unless effective wealth-equalizing institutions emerge at the global level. PMID:29183971

  10. Natural disasters and the lung.

    PubMed

    Robinson, Bruce; Alatas, Mohammad Fahmi; Robertson, Andrew; Steer, Henry

    2011-04-01

    As the world population expands, an increasing number of people are living in areas which may be threatened by natural disasters. Most of these major natural disasters occur in the Asian region. Pulmonary complications are common following natural disasters and can result from direct insults to the lung or may be indirect, secondary to overcrowding and the collapse in infrastructure and health-care systems which often occur in the aftermath of a disaster. Delivery of health care in disaster situations is challenging and anticipation of the types of clinical and public health problems faced in disaster situations is crucial when preparing disaster responses. In this article we review the pulmonary effects of natural disasters in the immediate setting and in the post-disaster aftermath and we discuss how this could inform planning for future disasters. © 2011 The Authors. Respirology © 2011 Asian Pacific Society of Respirology.

  11. Natural Medicines for Psychotic Disorders

    PubMed Central

    Hoenders, H.J. Rogier; Bartels-Velthuis, Agna A.; Vollbehr, Nina K.; Bruggeman, Richard; Knegtering, Henderikus; de Jong, Joop T.V.M.

    2018-01-01

    Abstract Patients with psychotic disorders regularly use natural medicines, although it is unclear whether these are effective and safe. The aim of this study was to provide an overview of evidence for improved outcomes by natural medicines. A systematic literature search was performed through Medline, PsycINFO, CINAHL, and Cochrane until May 2015. In 110 randomized controlled trials, evidence was found for glycine, sarcosine, N-acetylcysteine, some Chinese and ayurvedic herbs, ginkgo biloba, estradiol, and vitamin B6 to improve psychotic symptoms when added to antipsychotics. Ginkgo biloba and vitamin B6 seemed to reduce tardive dyskinesia and akathisia. Results on other compounds were negative or inconclusive. All natural agents, except reserpine, were well tolerated. Most study samples were small, study periods were generally short, and most results need replication. However, there is some evidence for beneficial effects of certain natural medicines. PMID:29373456

  12. Collective Memory of Violence of the Female Brown Body: A Decolonial Feminist Public Pedagogy Engagement with the Feminicides

    ERIC Educational Resources Information Center

    Trinidad Galván, Ruth

    2016-01-01

    Feminists have consistently engaged with ontological and epistemological issues about what counts as knowledge, based on whose worldview, and what knowledge and worldviews remain unrecognised or ignored. Utilising Mexicana and Chicana fictional and conceptual writings and public art installations on the Juárez feminicides, the article focuses on…

  13. Agricultural Policy and Child Health in Rural Mexico.

    ERIC Educational Resources Information Center

    Brown, Antoinette B.; Partridge, William L.

    1987-01-01

    Reports on the impact on malnutrition of Mexico's Sistema de Alementacion Mexicana (SAM) program, which tried to make the country self-sufficient in basic foods. Concludes that the food problem in Mexico is not so much one of production as it is a problem of distribution and consumption. (PS)

  14. Preface to "Should animal welfare be law or market driven?"

    USDA-ARS?s Scientific Manuscript database

    The Bioethics Symposium, entitled “Should animal welfare be law or market driven?” was held at the joint annual meeting of the American Dairy Science Association, American Society of Animal Science, Poultry Science Association, Asociación Mexicana de Producción Animal, and Canadian Society of Animal...

  15. Even beyond the Local Community: A Close Look at Latina Youths' Return Trips to Mexico

    ERIC Educational Resources Information Center

    Sanchez, Patricia

    2009-01-01

    Drawing from nearly four years of qualitative research, this article examines the lives of three second-generation mexicanas living in northern California who maintain close ties to their families' natal communities in Mexico. This ethnographic portrait outlines the contours of belonging in these spaces, including the affection and close…

  16. Chemical modifications of liquid natural rubber

    NASA Astrophysics Data System (ADS)

    Azhar, Nur Hanis Adila; Rasid, Hamizah Md; Yusoff, Siti Fairus M.

    2016-11-01

    Liquid natural rubber (LNR) was synthesized via photosentisized degradation of natural rubber (NR). LNR was modified into epoxidized liquid natural rubber (LENR) and hydroxylated liquid natural rubber (LNR-OH) using Na2WO4/CH3COOH/H2O2 catalytic system. Chemical structures of LNR and modified LNRs were characterized using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) and 1H Nuclear Magnetic Resonance (NMR) spectroscopies. Integration of 1H NMR was used to calculate the epoxy content (%) of LENR. 1H NMR detected the formation of LNR-OH after prolonged heating and increased of catalyst in oxidation reaction.

  17. The Journey of Recovery and Empowerment Embraced by Nature — Clients’ Perspectives on Nature-Based Rehabilitation in Relation to the Role of the Natural Environment

    PubMed Central

    Pálsdóttir, Anna María; Persson, Dennis; Persson, Birgitta; Grahn, Patrik

    2014-01-01

    This paper presents findings from real life situations, a longitudinal single case study on the role of natural environments in nature-based rehabilitation (NBR) for individuals with stress-related mental disorders, at the Alnarp Rehabilitation Garden in Sweden. A sample of 43 former clients voluntarily participated in semi-structured interview, and the data were analyzed according to interpretative phenomenological analysis (IPA). Three main superordinate themes were identified as the three phases of NBR—Prelude, Recuperating and Empowerment—explaining and illuminating the role of the natural environments in each phase. An explanatory model of NBR in this context is presented including the three phases of NBR, IRP supportive occupations and a pyramid of supporting environments. A new component of supportive environments was identified and herby named, Social quietness, an important component facilitating personal and intimate engagement with the natural environments. PMID:25026080

  18. Everyday Thoughts about Nature: An Interpretive Study of 16 Ninth Graders' Conceptualizations of Nature.

    ERIC Educational Resources Information Center

    Cobern, William W.; And Others

    This study investigates student world views in an effort to provide information that will improve the learning environment of the science classroom. The research focuses on furthering knowledge of students as people in the context of investigating what students think about nature or the natural world. The objective of the descriptive case study is…

  19. Natural Capital - putting a value on geological sites

    NASA Astrophysics Data System (ADS)

    Dunlop, Lesley

    2017-04-01

    Natural Capital is a mechanism through which a value can be placed on nature allowing it to be considered alongside other assets. When the Government of the United Kingdom produced a Natural Environment White Paper (The Natural Choice: securing the value of nature) in 2012 there was no direct mention of geosites, geoheritage or geodiversity. One ambition of the Natural Environment White Paper was to stop environmental degradation and to rebuild natural capital and to value it. Whilst landscapes are mentioned in the paper geodiversity is not directly and this has been problematic for funding and recognition within the UK. Natural Capital is being used as the basis for many of the environmental reviews therefore it is essential that geodiversity can be included within this. The Natural Capital Committee defines natural capital as 'those elements of the natural environment which provide valuable goods and services to people'. In the main, these goods and services are related to ecology/biodiversity rather than to the full range of natural capital. Specifically, the values associated with abiotic nature (geodiversity) are frequently undervalued or ignored. The English Geodiversity Forum have been producing case studies as to how this might be done for different locations and this paper will present the work of this and how a value can be attributed to geodiversity. For example links to tourism and recreation within areas such as the Jurassic Coast World Heritage Site and the Black Country proposed Geopark are easy to place a value on but it is more difficult with educational, scientific sites. Using an ecosystems services and biodiversity analogies this paper presents a framework that can be adopted for evaluation of geological sites. Defra (2015) The state of natural capital: protecting and improving natural capital for prosperity and wellbeing. Department for Environment, Food & Rural Affairs, 73 pages https

  20. Nature's Four Seasons as Inspiration.

    ERIC Educational Resources Information Center

    Bain, Christina; Padgelek, Mary

    1999-01-01

    Presents an instructional resource examining artwork by Charles Burchfield, Utagawa Hiroshige, Childe Hassam, and Georgia O'Keeffe that focuses on nature's four seasons. Offers activities to encourage students' observational skills and guide them to depict their personal views of nature in their own artwork (CMK)

  1. Natural pedagogy as evolutionary adaptation.

    PubMed

    Csibra, Gergely; Gergely, György

    2011-04-12

    We propose that the cognitive mechanisms that enable the transmission of cultural knowledge by communication between individuals constitute a system of 'natural pedagogy' in humans, and represent an evolutionary adaptation along the hominin lineage. We discuss three kinds of arguments that support this hypothesis. First, natural pedagogy is likely to be human-specific: while social learning and communication are both widespread in non-human animals, we know of no example of social learning by communication in any other species apart from humans. Second, natural pedagogy is universal: despite the huge variability in child-rearing practices, all human cultures rely on communication to transmit to novices a variety of different types of cultural knowledge, including information about artefact kinds, conventional behaviours, arbitrary referential symbols, cognitively opaque skills and know-how embedded in means-end actions. Third, the data available on early hominin technological culture are more compatible with the assumption that natural pedagogy was an independently selected adaptive cognitive system than considering it as a by-product of some other human-specific adaptation, such as language. By providing a qualitatively new type of social learning mechanism, natural pedagogy is not only the product but also one of the sources of the rich cultural heritage of our species.

  2. Natural pedagogy as evolutionary adaptation

    PubMed Central

    Csibra, Gergely; Gergely, György

    2011-01-01

    We propose that the cognitive mechanisms that enable the transmission of cultural knowledge by communication between individuals constitute a system of ‘natural pedagogy’ in humans, and represent an evolutionary adaptation along the hominin lineage. We discuss three kinds of arguments that support this hypothesis. First, natural pedagogy is likely to be human-specific: while social learning and communication are both widespread in non-human animals, we know of no example of social learning by communication in any other species apart from humans. Second, natural pedagogy is universal: despite the huge variability in child-rearing practices, all human cultures rely on communication to transmit to novices a variety of different types of cultural knowledge, including information about artefact kinds, conventional behaviours, arbitrary referential symbols, cognitively opaque skills and know-how embedded in means-end actions. Third, the data available on early hominin technological culture are more compatible with the assumption that natural pedagogy was an independently selected adaptive cognitive system than considering it as a by-product of some other human-specific adaptation, such as language. By providing a qualitatively new type of social learning mechanism, natural pedagogy is not only the product but also one of the sources of the rich cultural heritage of our species. PMID:21357237

  3. Effects of harvest on the sustainability and leaf productivity of populations of two palm species in Maya homegardens.

    PubMed

    Martínez-Ballesté, Andrea; Martorell, Carlos

    2015-01-01

    Traditional management practices are usually thought to be sustainable. The Maya manage Sabal (Arecaceae) palms in homegardens, using their leaves for thatching. The sustainability of such production systems depends on the long-term persistence of palm populations, whereas resource availability also depends on the number of leaves on individual palms. We examined how leaf harvest affects Sabal yapa and S. mexicana population growth rates (λ) and leaf production, comparing traditional and alternative harvest regimes in terms of sustainability and productivity. Demographic, harvest and leaf production data were recorded for three years in two homegardens. We used general integral projection models linked to leaf-production models to describe population dynamics and productivity. Harvest had no effect on S. yapa's vital rates or on λ, but it changed the growth rate of individuals of S. mexicana, with a negligible impact on λ. Homegardens affected λ values, reflecting the species' ecological affinities. S. mexicana, introduced from mesic forests, required watering and shade; therefore, its population declined rapidly in the homegarden that lacked both water and shade. The λ of the xerophilic S. yapa was slightly larger without watering than with watering. Palms usually compensated for leaf extraction, causing the number of leaves harvested per individual to increase with harvest intensity. Nevertheless, traditional management is relatively mild, allowing standing leaves to accumulate but reducing the homegarden's yield. Apparently, the Maya do not seek to maximize annual production but to ensure the availability of large numbers of leaves in homegardens. These leaves may then be used when the entire roof of a hut needs to be replaced every few years.

  4. Effects of Harvest on the Sustainability and Leaf Productivity of Populations of Two Palm Species in Maya Homegardens

    PubMed Central

    Martínez-Ballesté, Andrea; Martorell, Carlos

    2015-01-01

    Traditional management practices are usually thought to be sustainable. The Maya manage Sabal (Arecaceae) palms in homegardens, using their leaves for thatching. The sustainability of such production systems depends on the long-term persistence of palm populations, whereas resource availability also depends on the number of leaves on individual palms. We examined how leaf harvest affects Sabal yapa and S. mexicana population growth rates (λ) and leaf production, comparing traditional and alternative harvest regimes in terms of sustainability and productivity. Demographic, harvest and leaf production data were recorded for three years in two homegardens. We used general integral projection models linked to leaf-production models to describe population dynamics and productivity. Harvest had no effect on S. yapa’s vital rates or on λ, but it changed the growth rate of individuals of S. mexicana, with a negligible impact on λ. Homegardens affected λ values, reflecting the species’ ecological affinities. S. mexicana, introduced from mesic forests, required watering and shade; therefore, its population declined rapidly in the homegarden that lacked both water and shade. The λ of the xerophilic S. yapa was slightly larger without watering than with watering. Palms usually compensated for leaf extraction, causing the number of leaves harvested per individual to increase with harvest intensity. Nevertheless, traditional management is relatively mild, allowing standing leaves to accumulate but reducing the homegarden’s yield. Apparently, the Maya do not seek to maximize annual production but to ensure the availability of large numbers of leaves in homegardens. These leaves may then be used when the entire roof of a hut needs to be replaced every few years. PMID:25803029

  5. Nature's engineering: Giant magnetic exchange bias > 1T in a natural mineral

    NASA Astrophysics Data System (ADS)

    McEnroe, S. A.; Carter-Stiglitz, B.; Harrison, R. J.; Robinson, P.; McCammon, C.

    2006-12-01

    Magnetic exchange bias is a phenomenon whereby the hysteresis loop of a "soft" magnetic phase is shifted along the applied field axis by an amount of exchange due to interaction with a "hard" magnetic phase. Exchange bias is the subject of intense experimental and theoretical investigation because of its widespread technological applications and recent advances in manipulating nanoscale materials. Understanding the physical origin of exchange bias has been hampered, by the general uncertainty in the crystal and magnetic structure of the interface between hard and soft phases. Here we discuss a natural sample that has one of the largest exchange biases ever reported, nearly 1 Tesla (T) in a 1.5 T field and is the first documented example of exchange bias of this magnitude in a natural mineral. We demonstrate that exchange bias in this system is due to the interaction between coherently intergrown magnetic phases, formed through a natural process of phase separation during slow cooling. These extreme properties are found in a sample of titanohematite (15- 19 percent Ti-substitution ) from the 1 Gyr metamorphic rocks of the Modum district, south Norway. Low temperature magnetic measurements demonstrate the nature of the giant exchange bias. Transmission electron microscopy, electron microprobe analyses combined with Mossbauer measurements, at room and low temperature, are used to identify the interacting phases. The titanohematite contain ilmenite lamellae which are mostly sub-unit cell size. Fe-rutile is also present as an intergrowth phase.

  6. Environmentalism and natural aggregate mining

    USGS Publications Warehouse

    Drew, L.J.; Langer, W.H.; Sachs, J.S.

    2002-01-01

    Sustaining a developed economy and expanding a developing one require the use of large volumes of natural aggregate. Almost all human activity (commercial, recreational, or leisure) is transacted in or on facilities constructed from natural aggregate. In our urban and suburban worlds, we are almost totally dependent on supplies of water collected behind dams and transported through aqueducts made from concrete. Natural aggregate is essential to the facilities that produce energy-hydroelectric dams and coal-fired powerplants. Ironically, the utility created for mankind by the use of natural aggregate is rarely compared favorably with the environmental impacts of mining it. Instead, the empty quarries and pits are seen as large negative environmental consequences. At the root of this disassociation is the philosophy of environmentalism, which flavors our perceptions of the excavation, processing, and distribution of natural aggregate. The two end-member ideas in this philosophy are ecocentrism and anthropocentrism. Ecocentrism takes the position that the natural world is a organism whose arteries are the rivers-their flow must not be altered. The soil is another vital organ and must not be covered with concrete and asphalt. The motto of the ecocentrist is "man must live more lightly on the land." The anthropocentrist wants clean water and air and an uncluttered landscape for human use. Mining is allowed and even encouraged, but dust and noise from quarry and pit operations must be minimized. The large volume of truck traffic is viewed as a real menace to human life and should be regulated and isolated. The environmental problems that the producers of natural aggregate (crushed stone and sand and gravel) face today are mostly difficult social and political concerns associated with the large holes dug in the ground and the large volume of heavy truck traffic associated with quarry and pit operations. These concerns have increased in recent years as society's demand for

  7. What is Imbalance of Nature?

    NASA Astrophysics Data System (ADS)

    Kontar, V. A.

    2012-12-01

    The Mother Nature is imbalanced at all. The Mother Nature is every moment new, never returns to previous condition. The gravity and magnetosphere are changeable and imbalanced. The Sun is changeable and imbalanced. The climate is changeable and imbalanced. The atmosphere is changeable and imbalanced. The ocean is changeable and imbalanced. The crust and deep interior are changeable and imbalanced. The cryosphere is changeable and imbalanced. The life is simultaneously as the creator and the result of the imbalance of Nature. The people society is changeable and imbalanced. All chemical, physical, social, and other phenomenons are changeable and imbalanced. It's just that each phenomenon of the Mother Nature has some personal time-scale: one change in a nanosecond, and looks like for us as instable, i.e. imbalanced; while others change over millions years and, therefore, to us looks like not changeable, i.e. balanced. The scientists who are studying the Nature have convinced that the real balance never exist in Nature. Sometimes we can see something that is stable, i.e. balanced. But on closer study it appears that we are witnessing is not eternal rest and balance, it is not eternal STOP, but it is the perpetual motion, changing, there are a lot of imbalances. The balance it can be some result of the temporary mutual compensation the imbalanced processes in opposite directions. The balance it can be also some result of the inaccurate measurement, misunderstanding of conception or even request from bosses. But if we start use more accurate measurements, improve the models and not fear the bosses, than usually we got some new details. These new details show thet under the balanced visibility in really is hiding the interaction of many imbalanced processes of different directions. The balanced logic usually answers to question: What is it? The balanced answers are approximate and it will be updated many times during the development of science and practice. The

  8. TAILORING ACTIVATED CARBONS FOR ENHANCED REMOVAL OF NATURAL ORGANIC MATTER FROM NATURAL WATERS. (R828157)

    EPA Science Inventory

    Several pathways have been employed to systematically modify two granular activated carbons (GACs), F400 (coal-based) and Macro (wood-based), for examining adsorption of dissolved natural organic matter (DOM) from natural waters. A total of 24 activated carbons with different ...

  9. Natural light illumination system.

    PubMed

    Whang, Allen Jong-Woei; Chen, Yi-Yung; Yang, Shu-Hua; Pan, Po-Hsuan; Chou, Kao-Hsu; Lee, Yu-Chi; Lee, Zong-Yi; Chen, Chi-An; Chen, Cheng-Nan

    2010-12-10

    In recent years, green energy has undergone a lot of development and has been the subject of many applications. Many research studies have focused on illumination with sunlight as a means of saving energy and creating healthy lighting. Natural light illumination systems have collecting, transmitting, and lighting elements. Today, most daylight collectors use dynamic concentrators; these include Sun tracking systems. However, this design is too expensive to be cost effective. To create a low-cost collector that can be easily installed on a large building, we have designed a static concentrator, which is prismatic and cascadable, to collect sunlight for indoor illumination. The transmission component uses a large number of optical fibers. Because optical fibers are expensive, this means that most of the cost for the system will be related to transmission. In this paper, we also use a prismatic structure to design an optical coupler for coupling n to 1. With the n-to-1 coupler, the number of optical fibers necessary can be greatly reduced. Although this new natural light illumination system can effectively guide collected sunlight and send it to the basement or to other indoor places for healthy lighting, previously there has been no way to manage the collected sunlight when lighting was not desired. To solve this problem, we have designed an optical switch and a beam splitter to control and separate the transmitted light. When replacing traditional sources, the lighting should have similar characteristics, such as intensity distribution and geometric parameters, to those of traditional artificial sources. We have designed, simulated, and optimized an illumination lightpipe with a dot pattern to redistribute the collected sunlight from the natural light illumination system such that it equals the qualities of a traditional lighting system. We also provide an active lighting module that provides lighting from the natural light illumination system or LED auxiliary

  10. Public understandings of nature: a case study of local knowledge about "natural" forest conditions

    Treesearch

    R. Bruce Hull; David P. Robertson; Angelina Kendra

    2001-01-01

    This study is intended to serve as an explicit and specific example of the social construction of nature. It is motivated by the need to develop a more sophisticated language for a critical public dialogue about society's relationship with nature. We conducted a case study of environmental discourse in one local population in hopes of better understanding how a...

  11. Natural Cycles, Gases

    NASA Technical Reports Server (NTRS)

    Douglass, Anne R.; Jackman, Charles H.; Rood, R. B.; Aikin, A. C.; Stolarski, R. S.; Mccormick, M. P.; Fahey, David W.

    1992-01-01

    The major gaseous components of the exhaust of stratospheric aircraft are expected to be the products of combustion (CO2 and H2O), odd nitrogen (NO, NO2 HNO3), and products indicating combustion inefficiencies (CO and total unburned hydrocarbons). The species distributions are produced by a balance of photochemical and transport processes. A necessary element in evaluating the impact of aircraft exhaust on the lower stratospheric composition is to place the aircraft emissions in perspective within the natural cycles of stratospheric species. Following are a description of mass transport in the lower stratosphere and a discussion of the natural behavior of the major gaseous components of the stratospheric aircraft exhaust.

  12. Natural language modeling

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sharp, J.K.

    1997-11-01

    This seminar describes a process and methodology that uses structured natural language to enable the construction of precise information requirements directly from users, experts, and managers. The main focus of this natural language approach is to create the precise information requirements and to do it in such a way that the business and technical experts are fully accountable for the results. These requirements can then be implemented using appropriate tools and technology. This requirement set is also a universal learning tool because it has all of the knowledge that is needed to understand a particular process (e.g., expense vouchers, projectmore » management, budget reviews, tax, laws, machine function).« less

  13. The Australian Natural Disaster Resilience Index

    NASA Astrophysics Data System (ADS)

    Thoms, Martin

    2016-04-01

    The Australian Natural Disaster Resilience Index Martin Thoms, Melissa Parsons, Phil Morley Bushfire and Natural Hazards Cooperative Research Centre, Geography and Planning, University of New England, Armidale NSW 2351, Australia. Natural hazard management policy directions in Australia - and indeed internationally - are increasingly being aligned to ideas of resilience. Resilience to natural hazards is the ability of individuals and communities to cope with disturbance and adversity and to maintain adaptive behaviour. Operationalizing the measurement and assessment of disaster resilience is often undertaken using a composite index, but this exercise is yet to be undertaken in Australia. The Australian Natural Disaster Resilience Index is a top-down, national scale assessment of the resilience of communities to natural hazards. Resilience is assessed based on two sets of capacities: coping and adaptive capacities. Coping capacity relates to the factors influencing the ability of a community to prepare for, absorb and recover from a natural hazard event. Adaptive capacity relates to the arrangements and processes that enable adjustment through learning, adaptation and transformation. Indicators are derived under themes of social character, economic capital, infrastructure and planning, emergency services, community capital, information and engagement and governance/leadership/policy, using existing data sets (e.g. census data) or evaluation of policy and procedure (e.g. disaster management planning). A composite index of disaster resilience is then computed for each spatial division, giving national scale coverage. The results of the Australian Natural Disaster Resilience Index will be reported in a State of Disaster Resilience report, due in 2018. The index is co-designed with emergency service agencies, and will support policy development, planning, community engagement and emergency management.

  14. Effects of Human-Nature Interactions on Wildlife Habitat Dynamics: The Case of Wolong Nature Reserve for Giant Pandas

    NASA Astrophysics Data System (ADS)

    Vina, A.; Tuanmu, M.; Yang, W.; Liu, J.

    2012-12-01

    Human activities continue to induce the degradation of natural ecosystems, thus threatening not only the long-term survival of many wildlife species around the world, but also the resilience of natural ecosystems to global environmental changes. In response, many conservation efforts are emerging as adaptive strategies for coping with the degradation of natural ecosystems. Among them, the establishment of nature reserves is considered to be the most effective. However the effectiveness of nature reserves depends on the type and intensity of human activities occurring within their boundaries. But many of these activities constitute important livelihood systems for local human populations. Therefore, to enhance the effectiveness of conservation actions without significantly affecting local livelihood systems, it is essential to understand the complexity of human-nature interactions and their effects on the spatio-temporal dynamics of natural ecosystems. In this study, we evaluated the relation between giant panda habitat dynamics, conservation efforts and human activities in Wolong Nature Reserve for Giant Pandas, Sichuan Province, China. This reserve supports ca. 10% of the entire wild giant panda population but is also home to ca. 4,900 local residents. The spatio-temporal dynamics of giant panda habitat over the last four decades were analyzed using a time series of remotely sensed imagery acquired by different satellite sensor systems, including the Landsat Multi-Spectral Scanner, the Landsat Thematic Mapper and the Moderate Resolution Imaging Spectroradiometer (MODIS). Our assessment suggests that when local residents were actively involved in conservation efforts (through a payment for ecosystem services scheme established since around 2000) panda habitat started to recover, thus enhancing the resilience capacity of natural ecosystems in the Reserve. This reversed a long-term (> 30 years) trend of panda habitat degradation. The study not only has direct

  15. Thermal loading of natural streams

    USGS Publications Warehouse

    Jackman, Alan P.; Yotsukura, Nobuhiro

    1977-01-01

    The impact of thermal loading on the temperature regime of natural streams is investigated by mathematical models, which describe both transport (convection-diffusion) and decay (surface dissipation) of waste heat over 1-hour or shorter time intervals. The models are derived from the principle of conservation of thermal energy for application to one- and two-dimensional spaces. The basic concept in these models is to separate water temperature into two parts, (1) excess temperature due to thermal loading and (2) natural (ambient) temperature. This separation allows excess temperature to be calculated from the models without incoming radiation data. Natural temperature may either be measured in prototypes or calculated from the model. If use is made of the model, however, incoming radiation is required as input data. Comparison of observed and calculated temperatures in seven natural streams shows that the models are capable of predicting transient temperature regimes satisfactorily in most cases. (Woodard-USGS)

  16. The agents of natural genome editing.

    PubMed

    Witzany, Guenther

    2011-06-01

    The DNA serves as a stable information storage medium and every protein which is needed by the cell is produced from this blueprint via an RNA intermediate code. More recently it was found that an abundance of various RNA elements cooperate in a variety of steps and substeps as regulatory and catalytic units with multiple competencies to act on RNA transcripts. Natural genome editing on one side is the competent agent-driven generation and integration of meaningful DNA nucleotide sequences into pre-existing genomic content arrangements, and the ability to (re-)combine and (re-)regulate them according to context-dependent (i.e. adaptational) purposes of the host organism. Natural genome editing on the other side designates the integration of all RNA activities acting on RNA transcripts without altering DNA-encoded genes. If we take the genetic code seriously as a natural code, there must be agents that are competent to act on this code because no natural code codes itself as no natural language speaks itself. As code editing agents, viral and subviral agents have been suggested because there are several indicators that demonstrate viruses competent in both RNA and DNA natural genome editing.

  17. Toward the Dark Matter of Natural Products.

    PubMed

    Wakimoto, Toshiyuki

    2017-11-01

    Considering the dynamic features of natural products, our access toward exploring the entire diversity of natural products has been quite limited. It is challenging to assess the diversity of natural products by using conventional analytical methods, even with tandem chromatographic techniques, such as LC-MS and GC-MS. This viewpoint is supported by the sequencing analyses of microbial genomes, which have unveiled the potential of secondary metabolite production far exceeding the number of isolated molecules. Recent advancements in metabolomics, in concert with genomics analyses, have further extended the natural product diversity, prompting growing awareness of the existence of reactive or short-lived natural molecules. This personal account introduces some examples of the discoveries of hitherto elusive natural products, due to physico-chemical or biological reasons, and highlights the significance of the dark matter of natural products. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. A Citizen's Guide to Monitored Natural Attenuation

    EPA Pesticide Factsheets

    Citizen's Guide describing how natural attenuation relies on natural processes to decrease or attenuate concentrations of contaminants in soil and groundwater. Scientists monitor these conditions to make sure natural attenuation is working.

  19. Natural gas 1998: Issues and trends

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    Natural Gas 1998: Issues and Trends provides a summary of the latest data and information relating to the US natural gas industry, including prices, production, transmission, consumption, and the financial and environmental aspects of the industry. The report consists of seven chapters and five appendices. Chapter 1 presents a summary of various data trends and key issues in today`s natural gas industry and examines some of the emerging trends. Chapters 2 through 7 focus on specific areas or segments of the industry, highlighting some of the issues associated with the impact of natural gas operations on the environment. 57 figs.,more » 18 tabs.« less

  20. Backpocket: Activities for Nature Study.

    ERIC Educational Resources Information Center

    Hendry, Ian; And Others

    1995-01-01

    Leading naturalist-teachers share outdoor learning activities and techniques, including using binoculars as magnifiers, scavenger hunts, games such as "what's it called" and "I spy," insect study, guessing the age of trees by examining the bark, leading bird walks, exploring nature in the community, and enhancing nature hikes…

  1. Method and apparatus for dispensing compressed natural gas and liquified natural gas to natural gas powered vehicles

    DOEpatents

    Bingham, Dennis A.; Clark, Michael L.; Wilding, Bruce M.; Palmer, Gary L.

    2005-05-31

    A fueling facility and method for dispensing liquid natural gas (LNG), compressed natural gas (CNG) or both on-demand. The fueling facility may include a source of LNG, such as cryogenic storage vessel. A low volume high pressure pump is coupled to the source of LNG to produce a stream of pressurized LNG. The stream of pressurized LNG may be selectively directed through an LNG flow path or to a CNG flow path which includes a vaporizer configured to produce CNG from the pressurized LNG. A portion of the CNG may be drawn from the CNG flow path and introduced into the CNG flow path to control the temperature of LNG flowing therethrough. Similarly, a portion of the LNG may be drawn from the LNG flow path and introduced into the CNG flow path to control the temperature of CNG flowing therethrough.

  2. Wettability of natural superhydrophobic surfaces.

    PubMed

    Webb, Hayden K; Crawford, Russell J; Ivanova, Elena P

    2014-08-01

    Since the description of the 'Lotus Effect' by Barthlott and Neinhuis in 1997, the existence of superhydrophobic surfaces in the natural world has become common knowledge. Superhydrophobicity is associated with a number of possible evolutionary benefits that may be bestowed upon an organism, ranging from the ease of dewetting of their surfaces and therefore prevention of encumbrance by water droplets, self-cleaning and removal of particulates and potential pathogens, and even to antimicrobial activity. The superhydrophobic properties of natural surfaces have been attributed to the presence of hierarchical microscale (>1 μm) and nanoscale (typically below 200 nm) structures on the surface, and as a result, the generation of topographical hierarchy is usually considered of high importance in the fabrication of synthetic superhydrophobic surfaces. When one surveys the breadth of data available on naturally existing superhydrophobic surfaces, however, it can be observed that topographical hierarchy is not present on all naturally superhydrophobic surfaces; in fact, the only universal feature of these surfaces is the presence of a sophisticated nanoscale structure. Additionally, several natural surfaces, e.g. those present on rose petals and gecko feet, display high water contact angles and high adhesion of droplets, due to the pinning effect. These surfaces are not truly superhydrophobic, and lack significant degrees of nanoscale roughness. Here, we discuss the phenomena of superhydrophobicity and pseudo-superhydrophobicity in nature, and present an argument that while hierarchical surface roughness may aid in the stability of the superhydrophobic effect, it is nanoscale surface architecture alone that is the true determinant of superhydrophobicity. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Natural compounds and extracts from Mexican medicinal plants with anti-leishmaniasis activity: An update.

    PubMed

    Gutiérrez-Rebolledo, Gabriel Alfonso; Drier-Jonas, Susan; Jiménez-Arellanes, María Adelina

    2017-12-01

    Leishmaniasis is considered as an emerging, uncontrolled disease and is endemic in 98 countries. Annually, about 2 million cases of cutaneous and 500000 cases of visceral-type leishmaniasis are recorded and 60000 persons died from the disease. In Mexico, cutaneous leishmaniasis is known as chiclero's ulcer and is reported in 22 states, it is considered as a health problem. For its treatment, pentavalent antimonial drugs are administered. These drugs cause severe side effects, are costly. Drug-resistant cases have been reported and have been developing for over 70 years. One alternative to the drugs that are currently available is to find active molecules in medicinal plants. Dihydrocorynantheine, corynantheine and corynantheidine are active against Leishmania major, while harmane, pleiocarpin, buchtienin, luteolin and quercetin are active against Leishmania donovani. In Mexico, about 20 medicinal plants have been evaluated against Leishmania mexicana, among which the most active are Tridax procumbens, Lonchocarpus xuul and Pentalinon andrieuxii. From these plants, active compounds with IC 50  ≤ 30 μg/mL or μM have been isolated, such as 3(S)-16,17-didehydrofalcarinol or Oxylipin, cholestra-4,20,24-trien-3-one or pentalinosterol, 24-methylcholest-4-24(28)-dien-3-one, cholest-4-en-3-one, 6,7-dihydroneridie-none, neridienone, cholest-5,20,24-trien-3β-ol, and isocordoin. Today, only pentalinonsterol has been synthesized and assayed in the visceral leishmaniasis experimental model using BALB/c mice infected with Leishmania donovani. Liposome formulation of this compound administered by intravenous route at 2.5 mg/kg showed a significant reduction of parasite load in mouse liver and spleen. Copyright © 2017 Hainan Medical University. Production and hosting by Elsevier B.V. All rights reserved.

  4. Natural ecosystems

    USGS Publications Warehouse

    Fleishman, Erica; Belnap, Jayne; Cobb, Neil; Enquist, Carolyn A.F.; Ford, Karl; MacDonald, Glen; Pellant, Mike; Schoennagel, Tania; Schmit, Lara M.; Schwartz, Mark; van Drunick, Suzanne; Westerling, Anthony LeRoy; Keyser, Alisa; Lucas, Ryan

    2013-01-01

    Natural Ecosystems analyzes the association of observed changes in climate with changes in the geographic distributions and phenology (the timing of blossoms or migrations of birds) for Southwestern ecosystems and their species, portraying ecosystem disturbances—such as wildfires and outbreaks of forest pathogens—and carbon storage and release, in relation to climate change.

  5. EEMD-MUSIC-Based Analysis for Natural Frequencies Identification of Structures Using Artificial and Natural Excitations

    PubMed Central

    Amezquita-Sanchez, Juan P.; Romero-Troncoso, Rene J.; Osornio-Rios, Roque A.; Garcia-Perez, Arturo

    2014-01-01

    This paper presents a new EEMD-MUSIC- (ensemble empirical mode decomposition-multiple signal classification-) based methodology to identify modal frequencies in structures ranging from free and ambient vibration signals produced by artificial and natural excitations and also considering several factors as nonstationary effects, close modal frequencies, and noisy environments, which are common situations where several techniques reported in literature fail. The EEMD and MUSIC methods are used to decompose the vibration signal into a set of IMFs (intrinsic mode functions) and to identify the natural frequencies of a structure, respectively. The effectiveness of the proposed methodology has been validated and tested with synthetic signals and under real operating conditions. The experiments are focused on extracting the natural frequencies of a truss-type scaled structure and of a bridge used for both highway traffic and pedestrians. Results show the proposed methodology as a suitable solution for natural frequencies identification of structures from free and ambient vibration signals. PMID:24683346

  6. EEMD-MUSIC-based analysis for natural frequencies identification of structures using artificial and natural excitations.

    PubMed

    Camarena-Martinez, David; Amezquita-Sanchez, Juan P; Valtierra-Rodriguez, Martin; Romero-Troncoso, Rene J; Osornio-Rios, Roque A; Garcia-Perez, Arturo

    2014-01-01

    This paper presents a new EEMD-MUSIC- (ensemble empirical mode decomposition-multiple signal classification-) based methodology to identify modal frequencies in structures ranging from free and ambient vibration signals produced by artificial and natural excitations and also considering several factors as nonstationary effects, close modal frequencies, and noisy environments, which are common situations where several techniques reported in literature fail. The EEMD and MUSIC methods are used to decompose the vibration signal into a set of IMFs (intrinsic mode functions) and to identify the natural frequencies of a structure, respectively. The effectiveness of the proposed methodology has been validated and tested with synthetic signals and under real operating conditions. The experiments are focused on extracting the natural frequencies of a truss-type scaled structure and of a bridge used for both highway traffic and pedestrians. Results show the proposed methodology as a suitable solution for natural frequencies identification of structures from free and ambient vibration signals.

  7. Nature's ups and downs

    NASA Astrophysics Data System (ADS)

    Rodgers, Peter

    2015-12-01

    When Norman Lockyer, an astronomer and science writer with a day job as a clerk at the War Office in London, approached the publishing house Macmillan and Company in 1869 with a proposal for a new weekly journal about science, few could have predicted the outcome. The journal in question was Nature, and given its influence over the past 146 years, it is hard to believe that Melinda Baldwin's Making Nature is the first full-length book to be written about it.

  8. Crack Velocities in Natural Rubber.

    DTIC Science & Technology

    1982-05-01

    vulcanized natural rubber (3). The surprisingly low value for natural rubber was attributed to highly anisotropic elastic behavior at high strains...Dr. R.L. Rabie Hercules Incorporated WX-2, MS-952 Alleghany Ballistic Lab Los Alamos National Lab. P.O. Box 210 P.O. Box 1663 Washington, D.C. 21502

  9. Evaluation of Natural Resource Interventions

    ERIC Educational Resources Information Center

    Rowe, Andy

    2012-01-01

    This article provides a frame for evaluation of natural resource interventions, which necessarily involves both human and natural systems. Two-system evaluands require us to adapt evaluation methods for comparison and attribution and to address differences in time and space occurring across the systems as well as potentially very different values…

  10. Beholding Nature: Contemplation and Connectedness

    ERIC Educational Resources Information Center

    Chambliss, Kathleen Mary

    2013-01-01

    Two related exploratory studies, one with families, and a second one with adult and child members of an independent school community, suggest that our connections with the rhythms, processes, species, and cycles of nature, our "love" and feelings of affinity for nature, can be strengthened by practicing contemplation outdoors. In The…

  11. Natural Learning Case Study Archives

    ERIC Educational Resources Information Center

    Lawler, Robert W.

    2015-01-01

    Natural Learning Case Study Archives (NLCSA) is a research facility for those interested in using case study analysis to deepen their understanding of common sense knowledge and natural learning (how the mind interacts with everyday experiences to develop common sense knowledge). The database comprises three case study corpora based on experiences…

  12. "Mexico in Transition." Curriculum Units.

    ERIC Educational Resources Information Center

    Oregon Univ., Eugene. Foreign Language Resource Center.

    These curriculum units were developed in a National Endowment for the Humanities 1994 summer seminar "Mexico in Transition." The 23 lessons are written in Spanish. Lessons are entitled: (1) "La Migracion Mexicana Vista a Traves del Cuento 'Paso del Norte' de Juan Rulfo" (Jose Jorge Armendariz); (2) "Los Grupos Indigenas de…

  13. The Geography Olympiad in Mexico

    ERIC Educational Resources Information Center

    Garcia-Garcia, Fernando

    2007-01-01

    The formal organisation of science Olympiads in Mexico dates from 1987, when a national contest on Mathematics was held in order to identify a team to represent the country in the International Mathematics Olympiad. In 1991, the Mexican Academy of Sciences ("Academia Mexicana de Ciencias"-AMC) created the National Science Olympiads…

  14. Distribution and Status of Sclerocactus polyancistrus on the Naval Weapons Center-A Survey.

    DTIC Science & Technology

    1982-10-01

    Ephedra viridis , Ephedra nevadensis, Purshia glandulosa, Yucca brevifolia, Haplopappus linearifolius, Tetradymia sp. GEOLOGICAL SETTING & SOILS: Mesozoic...Haplopappus Cooperi, Ephedra nevadensis, Ephedra viridis , Grayia spinosa, Lycium Andersonii, Salazaria mexicana, Yucca brevifolia, Purshia glandulosa...1740 m. (5100-5700 ft.) PLANT COMMUNITY: Coleogyne ramosissima(predominantly east of road), Ephedra nevadensis, Ephedra viridis , Haplopappus Cooperi

  15. Apparent Changes in the Abundance and Distribution of Anopheles Species on Grenada Island

    DTIC Science & Technology

    1993-01-01

    entomolbgica en Mexico, pp. 15-40. In: Me- morias del IV Simposio Nacional Entomologia Med- ica y Veterinaria, Oaxtepec, Mor., Mexico. Sociedad...Mexicana de Entomologia . Root, F. M. and J. Andrews. 1938. Malaria and anonheline survey of Grenada, B.W.I. Am. J. H Y ~ . 27:549-579. - Shannon, R

  16. Sheep symposium: Biology and management of low-input lambing in easy-care systems

    USDA-ARS?s Scientific Manuscript database

    Low-input lambing management was the focus of the 2007 Sheep Symposium at the joint annual meetings of the American Society of Animal Science, the American Dairy Science Association, the Asociacio´n Mexicana de Produccio´n Animal, and the Poultry Science Association held in San Antonio, Texas, on Ju...

  17. Biomimetics: lessons from nature--an overview.

    PubMed

    Bhushan, Bharat

    2009-04-28

    Nature has developed materials, objects and processes that function from the macroscale to the nanoscale. These have gone through evolution over 3.8 Gyr. The emerging field of biomimetics allows one to mimic biology or nature to develop nanomaterials, nanodevices and processes. Properties of biological materials and surfaces result from a complex interplay between surface morphology and physical and chemical properties. Hierarchical structures with dimensions of features ranging from the macroscale to the nanoscale are extremely common in nature to provide properties of interest. Molecular-scale devices, superhydrophobicity, self-cleaning, drag reduction in fluid flow, energy conversion and conservation, high adhesion, reversible adhesion, aerodynamic lift, materials and fibres with high mechanical strength, biological self-assembly, antireflection, structural coloration, thermal insulation, self-healing and sensory-aid mechanisms are some of the examples found in nature that are of commercial interest. This paper provides a broad overview of the various objects and processes of interest found in nature and applications under development or available in the marketplace.

  18. Nature apps: Waiting for the revolution.

    PubMed

    Jepson, Paul; Ladle, Richard J

    2015-12-01

    Apps are small task-orientated programs with the potential to integrate the computational and sensing capacities of smartphones with the power of cloud computing, social networking, and crowdsourcing. They have the potential to transform how humans interact with nature, cause a step change in the quantity and resolution of biodiversity data, democratize access to environmental knowledge, and reinvigorate ways of enjoying nature. To assess the extent to which this potential is being exploited in relation to nature, we conducted an automated search of the Google Play Store using 96 nature-related terms. This returned data on ~36 304 apps, of which ~6301 were nature-themed. We found that few of these fully exploit the full range of capabilities inherent in the technology and/or have successfully captured the public imagination. Such breakthroughs will only be achieved by increasing the frequency and quality of collaboration between environmental scientists, information engineers, computer scientists, and interested publics.

  19. [Jena philosophies of nature around 1800].

    PubMed

    Breidbach, O

    2000-01-01

    This paper describes the situation and the outline of positions in philosophy of nature in Jena about 1800, in focusing on research other than the key figures Schelling and Hegel. In 1789, Schelling introduced philosophy of nature into the course program of Jena University. Already in 1800, two young scientists--a mathematician (Fischer) and a physiologist--reacted, announcing lectures on Schellingian topics. But only in late 1802, younger philosophers offered courses on those topics. From 1802 onwards, lectures were announced by Schad, Krause, Henrici, Hegel, Oken and the botanist Schelver. Apart from the Fisher lecture from 1800, the program of these presentations was based on Schellingian principles. Analyses of the ideas of Schad, Krause and Schelver show that, about 1800, philosophy of nature in Jena conserved basic ideas of the early philosophy of nature of Schelling. Thus, philosophy of nature in this period of Jena University seemed to follow just one line of reasoning.

  20. Cancer wars: natural products strike back

    PubMed Central

    Basmadjian, Christine; Zhao, Qian; Bentouhami, Embarek; Djehal, Amel; Nebigil, Canan G.; Johnson, Roger A.; Serova, Maria; de Gramont, Armand; Faivre, Sandrine; Raymond, Eric; Désaubry, Laurent G.

    2014-01-01

    Natural products have historically been a mainstay source of anticancer drugs, but in the 90's they fell out of favor in pharmaceutical companies with the emergence of targeted therapies, which rely on antibodies or small synthetic molecules identified by high throughput screening. Although targeted therapies greatly improved the treatment of a few cancers, the benefit has remained disappointing for many solid tumors, which revitalized the interest in natural products. With the approval of rapamycin in 2007, 12 novel natural product derivatives have been brought to market. The present review describes the discovery and development of these new anticancer drugs and highlights the peculiarities of natural product and new trends in this exciting field of drug discovery. PMID:24822174

  1. Francis Bacon and the classification of natural history.

    PubMed

    Anstey, Peter

    2012-01-01

    This paper analyses the place of natural history within Bacon's divisions of the sciences in The Advancement of Learning (1605) and the later De dignitate et augmentis scientiarum (1623). It is shown that at various points in Bacon's divisions, natural history converges or overlaps with natural philosophy, and that, for Bacon, natural history and natural philosophy are not discrete disciplines. Furthermore, it is argued that Bacon's distinction between operative and speculative natural philosophy and the place of natural history within this distinction, are discontinuous with the later distinction between experimental and speculative philosophy that emerged in the methodology of the Fellows of the early Royal Society.

  2. Integrating climate forecasts and natural gas supply information into a natural gas purchasing decision

    NASA Astrophysics Data System (ADS)

    Changnon, David; Ritsche, Michael; Elyea, Karen; Shelton, Steve; Schramm, Kevin

    2000-09-01

    This paper illustrates a key lesson related to most uses of long-range climate forecast information, namely that effective weather-related decision-making requires understanding and integration of weather information with other, often complex factors. Northern Illinois University's heating plant manager and staff meteorologist, along with a group of meteorology students, worked together to assess different types of available information that could be used in an autumn natural gas purchasing decision. Weather information assessed included the impact of ENSO events on winters in northern Illinois and the Climate Prediction Center's (CPC) long-range climate outlooks. Non-weather factors, such as the cost and available supplies of natural gas prior to the heating season, contribute to the complexity of the natural gas purchase decision. A decision tree was developed and it incorporated three parts: (a) natural gas supply levels, (b) the CPC long-lead climate outlooks for the region, and (c) an ENSO model developed for DeKalb. The results were used to decide in autumn whether to lock in a price or ride the market each winter. The decision tree was tested for the period 1995-99, and returned a cost-effective decision in three of the four winters.

  3. Natural Gas Industry and Markets

    EIA Publications

    2006-01-01

    This special report provides an overview of the supply and disposition of natural gas in 2004 and is intended as a supplement to the Energy Information Administration's (EIA) Natural Gas Annual 2004 (NGA). Unless otherwise stated, all data and figures in this report are based on summary statistics published in the NGA 2004.

  4. Discovering Nature with Young Children.

    ERIC Educational Resources Information Center

    Chalufour, Ingrid; Worth, Karen

    Young children's curiosity about nature and their need to make sense of the world presents an opportunity to incorporate science as a natural and critical part of children's early learning. This guide, part of a preschool science curriculum, uses an inquiry approach to encourage young naturalists to observe life more closely, build an…

  5. Removal of Iron and Manganese from Natural Groundwater by Continuous Reactor Using Activated and Natural Mordenite Mineral Adsorption

    NASA Astrophysics Data System (ADS)

    Zevi, Y.; Dewita, S.; Aghasa, A.; Dwinandha, D.

    2018-01-01

    Mordenite minerals derived from Sukabumi natural green stone founded in Indonesia was tested in order to remove iron and manganese from natural groundwater. This research used two types of adsorbents which were consisted of physically activated and natural mordenite. Physical activation of the mordenite was carried out by heating at 400-600°C for two hours. Batch system experiments was also conducted as a preliminary experiment. Batch system proved that both activated and natural mordenite minerals were capable of reducing iron and manganese concentration from natural groundwater. Then, continuous experiment was conducted using down-flow system with 45 ml/minute of constant flow rate. The iron & manganese removal efficiency using continuous reactor for physically activated and natural mordenite were 1.38-1.99%/minute & 0.8-1.49%/minute and 2.26%/minute & 1.37-2.26%/minute respectively. In addition, the regeneration treatment using NH4Cl solution managed to improve the removal efficiency of iron & manganese to 1.98%/minute & 1.77-1.90%/minute and 2.25%/minute & 2.02-2.21%/minute on physically activated mordenite and natural mordenite respectively. Subsequently, the activation of the new mordenite was carried out by immersing mordenite in NH4Cl solution. This chemical activation showed 2.42-2.75%/minute & 0.96 - 2.67 %/minute and 2.66 - 2.78 %/minute & 1.34 - 2.32 %/minute of iron & manganese removal efficiency per detention time for chemically activated and natural mordenite respectively.

  6. [The rural-urban nature and geographical nature of patterns of internal migration].

    PubMed

    Raczynski, D

    1981-07-01

    The rural-urban nature and geographical patterns of internal migration in Chile are studied. The magnitude, nature, and relative importance of rural-urban, interurban, inter-rural, and urban-rural movements in the country are examined, with a focus on the impact of internal migration on urbanization and on the demographic growth of cities and rural areas. Rural and urban differentials in propensity to migrate and in the capacity to attract and retain population are investigated using 1970 census data on migratory flows to and from the Santiago metropolitan area and those directed to other parts of the country.

  7. 18 CFR 382.202 - Annual charges under the Natural Gas Act and Natural Gas Policy Act of 1978 and related statutes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the Natural Gas Act and Natural Gas Policy Act of 1978 and related statutes. 382.202 Section 382.202... GENERAL RULES ANNUAL CHARGES Annual Charges § 382.202 Annual charges under the Natural Gas Act and Natural Gas Policy Act of 1978 and related statutes. The adjusted costs of administration of the natural gas...

  8. 18 CFR 382.202 - Annual charges under the Natural Gas Act and Natural Gas Policy Act of 1978 and related statutes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... the Natural Gas Act and Natural Gas Policy Act of 1978 and related statutes. 382.202 Section 382.202... GENERAL RULES ANNUAL CHARGES Annual Charges § 382.202 Annual charges under the Natural Gas Act and Natural Gas Policy Act of 1978 and related statutes. The adjusted costs of administration of the natural gas...

  9. THE ROLE OF NATURAL BIOLOGICAL PROCESSES IN THE NATURAL ATTENUATION OF CONTAMINANTS IN GROUND WATER

    EPA Science Inventory

    As a practical matter, the time required for a site to reach cleanup goals is controlled by the rate of natural attenuation of the source of contamination, not the rate of natural attenuation of the contaminants once they are in the ground. As a consequence, in the USA the most ...

  10. Increasing Children's Positive Connection to, Orientation toward, and Knowledge of Nature through Nature Camp Experiences

    ERIC Educational Resources Information Center

    San Jose, Alyssa L.; Nelson, Keith E.

    2017-01-01

    What do children actually carry away from participating in planned activities in natural areas such as those in outdoor camps and schools? Prior research has seldom been rigorous in establishing participants' connection to, knowledge of, and orientation toward nature before intervention, followed by a clear specification of what range of…

  11. In silico polypharmacology of natural products.

    PubMed

    Fang, Jiansong; Liu, Chuang; Wang, Qi; Lin, Ping; Cheng, Feixiong

    2017-04-27

    Natural products with polypharmacological profiles have demonstrated promise as novel therapeutics for various complex diseases, including cancer. Currently, many gaps exist in our knowledge of which compounds interact with which targets, and experimentally testing all possible interactions is infeasible. Recent advances and developments of systems pharmacology and computational (in silico) approaches provide powerful tools for exploring the polypharmacological profiles of natural products. In this review, we introduce recent progresses and advances of computational tools and systems pharmacology approaches for identifying drug targets of natural products by focusing on the development of targeted cancer therapy. We survey the polypharmacological and systems immunology profiles of five representative natural products that are being considered as cancer therapies. We summarize various chemoinformatics, bioinformatics and systems biology resources for reconstructing drug-target networks of natural products. We then review currently available computational approaches and tools for prediction of drug-target interactions by focusing on five domains: target-based, ligand-based, chemogenomics-based, network-based and omics-based systems biology approaches. In addition, we describe a practical example of the application of systems pharmacology approaches by integrating the polypharmacology of natural products and large-scale cancer genomics data for the development of precision oncology under the systems biology framework. Finally, we highlight the promise of cancer immunotherapies and combination therapies that target tumor ecosystems (e.g. clones or 'selfish' sub-clones) via exploiting the immunological and inflammatory 'side' effects of natural products in the cancer post-genomics era. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. The Case for Natural History

    ERIC Educational Resources Information Center

    King, Heather; Achiam, Marianne

    2017-01-01

    Fundamental knowledge of natural history is lacking in many western societies, as demonstrated by its absence in school science curricula. And yet, to meet local and global challenges such as environmental degradation, biodiversity loss and climate change, we need to better understand the living and non-living parts of the natural world. Many have…

  13. Teaching about Natural Background Radiation

    ERIC Educational Resources Information Center

    Al-Azmi, Darwish; Karunakara, N.; Mustapha, Amidu O.

    2013-01-01

    Ambient gamma dose rates in air were measured at different locations (indoors and outdoors) to demonstrate the ubiquitous nature of natural background radiation in the environment and to show that levels vary from one location to another, depending on the underlying geology. The effect of a lead shield on a gamma radiation field was also…

  14. Illinois Birds. Nature Discovery I.

    ERIC Educational Resources Information Center

    Stone, Sally F.

    The birds of Illinois and their particular habitats are explored in this guide which is a part of a series of Nature Discovery publications. The materials are designed to directly supplement the natural science curricula and to complement other subject areas including social studies, language arts, music, and art. The program is formated for…

  15. Natural Gas and Cellulosic Biomass: A Clean Fuel Combination? Determining the Natural Gas Blending Wall in Biofuel Production.

    PubMed

    M Wright, Mark; Seifkar, Navid; Green, William H; Román-Leshkov, Yuriy

    2015-07-07

    Natural gas has the potential to increase the biofuel production output by combining gas- and biomass-to-liquids (GBTL) processes followed by naphtha and diesel fuel synthesis via Fischer-Tropsch (FT). This study reflects on the use of commercial-ready configurations of GBTL technologies and the environmental impact of enhancing biofuels with natural gas. The autothermal and steam-methane reforming processes for natural gas conversion and the gasification of biomass for FT fuel synthesis are modeled to estimate system well-to-wheel emissions and compare them to limits established by U.S. renewable fuel mandates. We show that natural gas can enhance FT biofuel production by reducing the need for water-gas shift (WGS) of biomass-derived syngas to achieve appropriate H2/CO ratios. Specifically, fuel yields are increased from less than 60 gallons per ton to over 100 gallons per ton with increasing natural gas input. However, GBTL facilities would need to limit natural gas use to less than 19.1% on a LHV energy basis (7.83 wt %) to avoid exceeding the emissions limits established by the Renewable Fuels Standard (RFS2) for clean, advanced biofuels. This effectively constitutes a blending limit that constrains the use of natural gas for enhancing the biomass-to-liquids (BTL) process.

  16. Making Time for Nature: Visual Exposure to Natural Environments Lengthens Subjective Time Perception and Reduces Impulsivity

    PubMed Central

    Berry, Meredith S.; Repke, Meredith A.; Nickerson, Norma P.; Conway, Lucian G.; Odum, Amy L.; Jordan, Kerry E.

    2015-01-01

    Impulsivity in delay discounting is associated with maladaptive behaviors such as overeating and drug and alcohol abuse. Researchers have recently noted that delay discounting, even when measured by a brief laboratory task, may be the best predictor of human health related behaviors (e.g., exercise) currently available. Identifying techniques to decrease impulsivity in delay discounting, therefore, could help improve decision-making on a global scale. Visual exposure to natural environments is one recent approach shown to decrease impulsive decision-making in a delay discounting task, although the mechanism driving this result is currently unknown. The present experiment was thus designed to evaluate not only whether visual exposure to natural (mountains, lakes) relative to built (buildings, cities) environments resulted in less impulsivity, but also whether this exposure influenced time perception. Participants were randomly assigned to either a natural environment condition or a built environment condition. Participants viewed photographs of either natural scenes or built scenes before and during a delay discounting task in which they made choices about receiving immediate or delayed hypothetical monetary outcomes. Participants also completed an interval bisection task in which natural or built stimuli were judged as relatively longer or shorter presentation durations. Following the delay discounting and interval bisection tasks, additional measures of time perception were administered, including how many minutes participants thought had passed during the session and a scale measurement of whether time "flew" or "dragged" during the session. Participants exposed to natural as opposed to built scenes were less impulsive and also reported longer subjective session times, although no differences across groups were revealed with the interval bisection task. These results are the first to suggest that decreased impulsivity from exposure to natural as opposed to built

  17. The "balance of nature"-evolution of a Panchreston.

    PubMed

    Simberloff, Daniel

    2014-10-01

    The earliest concept of a balance of nature in Western thought saw it as being provided by gods but requiring human aid or encouragement for its maintenance. With the rise of Greek natural philosophy, emphasis shifted to traits gods endowed species with at the outset, rather than human actions, as key to maintaining the balance. The dominance of a constantly intervening God in the Middle Ages lessened interest in the inherent features of nature that would contribute to balance, but the Reformation led to renewed focus on such features, particularly traits of species that would maintain all of them but permit none to dominate nature. Darwin conceived of nature in balance, and his emphasis on competition and frequent tales of felicitous species interactions supported the idea of a balance of nature. But Darwin radically changed its underlying basis, from God to natural selection. Wallace was perhaps the first to challenge the very notion of a balance of nature as an undefined entity whose accuracy could not be tested. His skepticism was taken up again in the 20th century, culminating in a widespread rejection of the idea of a balance of nature by academic ecologists, who focus rather on a dynamic, often chaotic nature buffeted by constant disturbances. The balance-of-nature metaphor, however, lives on in large segments of the public, representing a fragile aspect of nature and biodiversity that it is our duty to protect.

  18. Nature speaks - an exploratory study of nature as inspiration

    Treesearch

    Will LaPage

    2001-01-01

    Artists, composers, writers, and photographers who have been inspired by Acadia National Park and Baxter State Park, share their thoughts about the importance of nature to creativity, their feelings about park landscapes, their need for personal expression and the importance of sharing the inspirational experience. Implications for a better understanding of the park...

  19. Workshop held on natural disasters

    NASA Astrophysics Data System (ADS)

    Rundle, John; Klein, W.; Turcotte, D.

    Natural hazards such as earthquakes and floods are a menace to the population worldwide. The United Nations focused attention on this global problem by declaring the 1990s the Decade of Natural Hazard Reduction. In addition to threatening human life, natural hazards can cause severe economic hardship locally and, in an ever more complex and interactive world economy, dislocations that are felt in areas far beyond the site of a disaster.Recent catastrophic earthquakes, hurricanes, floods, and fires have called into question the ability of private insurers to cover economic losses. Unlimited liability is a necessity for confidence in insurance coverage, but these events have stretched the resources of even the largest insurers.

  20. The Online Dissemination of Nature-Health Concepts: Lessons from Sentiment Analysis of Social Media Relating to "Nature-Deficit Disorder".

    PubMed

    Palomino, Marco; Taylor, Tim; Göker, Ayse; Isaacs, John; Warber, Sara

    2016-01-19

    Evidence continues to grow supporting the idea that restorative environments, green exercise, and nature-based activities positively impact human health. Nature-deficit disorder, a journalistic term proposed to describe the ill effects of people's alienation from nature, is not yet formally recognized as a medical diagnosis. However, over the past decade, the phrase has been enthusiastically taken up by some segments of the lay public. Social media, such as Twitter, with its opportunities to gather "big data" related to public opinions, offers a medium for exploring the discourse and dissemination around nature-deficit disorder and other nature-health concepts. In this paper, we report our experience of collecting more than 175,000 tweets, applying sentiment analysis to measure positive, neutral or negative feelings, and preliminarily mapping the impact on dissemination. Sentiment analysis is currently used to investigate the repercussions of events in social networks, scrutinize opinions about products and services, and understand various aspects of the communication in Web-based communities. Based on a comparison of nature-deficit-disorder "hashtags" and more generic nature hashtags, we make recommendations for the better dissemination of public health messages through changes to the framing of messages. We show the potential of Twitter to aid in better understanding the impact of the natural environment on human health and wellbeing.