Ventura-Martínez, Rosa; Rodríguez, Rodolfo; González-Trujano, María Eva; Ángeles-López, Guadalupe E; Déciga-Campos, Myrna; Gómez, Claudia
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
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
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.
Martín-Quintal, Zhelmy; Moo-Puc, Rosa; González-Salazar, Francisco; Chan-Bacab, Manuel J; Torres-Tapia, Luis W; Peraza-Sánchez, Sergio R
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.
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...
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
Rezvan, H; Rees, R; Ali, SA
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
Cryan, P.M.; Bogan, M.A.
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.
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
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
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
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.
Navarrete, Andrés; Ávila-Rosas, Natalia; Majín-León, Mateo; Balderas-López, José Luis; Alfaro-Romero, Alejandro; Tavares-Carvalho, José Carlos
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.
Xiong, Jiu-Qiang; Kurade, Mayur B; Abou-Shanab, Reda A I; Ji, Min-Kyu; Choi, Jaeyoung; Kim, Jong Oh; Jeon, Byong-Hun
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.
Arguello, C.; Acosta-Avalos, D.; Alvarado-Gil, J. J.; Vargas, H.
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.
Grunert, Patrick; Rosenthal, Yair; Jorissen, Frans; Holbourn, Ann
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).
Gamboa-León, M R; Aranda-González, I; Mut-Martín, M; García-Miss, M R; Dumonteil, E
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.
Estrada-Reyes, R.; Ferreyra-Cruz, O. A.
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
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.
Hung, J.; Castillo, J.; Jiménez, G.; Hasegawa, M.; Rodriguez, M.
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.
Hassani, Kasra; Antoniak, Elisabeth; Jardim, Armando; Olivier, Martin
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
Montoya-Lerma, J; Cadena, H; Segura, I; Travi, B L
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.
Torres-Martínez, Aarón; Hernández-Franyutti, Arlette; Uribe, Mari Carmen; Contreras-Sánchez, Wilfrido Miguel
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.
Pérez-Vega, Jorge Humberto; López-Moreno, Carmina Yanett; López-Valenzuela, José Angel; Rendón-Maldonado, José Guadalupe; López-Moreno, Héctor Samuel
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.
Caro-Borrero, A; Carmona-Jiménez, J
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.
Chaffee, M.A.; Gale, C.W.
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.
Sosa-Provencio, Mia Angélica
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,…
Lu, Xiang; Zhou, Xuan; Cao, Yu; Zhou, Meixue; McNeil, David; Liang, Shan; Yang, Chengwei
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.
Lu, Xiang; Zhou, Xuan; Cao, Yu; Zhou, Meixue; McNeil, David; Liang, Shan; Yang, Chengwei
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
Ruiz-Toledo, Jovani; Vandame, Rémy; Castro-Chan, Ricardo Alberto; Penilla-Navarro, Rosa Patricia; Gómez, Jaime; Sánchez, Daniel
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.
Navarro-García, Victor M; Rojas, Gabriela; Avilés, Margarita; Fuentes, Macrina; Zepeda, Gerardo
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.
Rodriguez-Contreras, Dayana; Hamilton, Nicklas
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
Fernández-Figueroa, Edith A.; Rangel-Escareño, Claudia; Espinosa-Mateos, Valeria; Carrillo-Sánchez, Karol; Salaiza-Suazo, Norma; Carrada-Figueroa, Georgina; March-Mifsut, Santiago; Becker, Ingeborg
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
Allen, Christine; Torres-Peimbert, Silvia
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.
Schulz-Mirbach, Tanja; Hess, Martin; Plath, Martin
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.
Sánchez-García, Laura; Berzunza-Cruz, Miriam; Becker-Fauser, Ingeborg; Rebollar-Téllez, Eduardo A
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.
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.
Sánchez, D; Vandame, R
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.
Barral-Netto, M.; Sadigursky, M.; Reed, S. G.; Sonnenfeld, G.
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.
F. Thomas Ledig; Paul D. Hodgskiss; Virginia Jacob-Cervantes
Mexican spruce (Picea mexicana MartÃnez), an endangered species of the highest sky islands in MÃ©xicoâs 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...
Riesch, R; Plath, M; Schlupp, I
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.
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Bagstad, Kenneth J.; Widerholdt, Ruscena
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.
Mueller, Matthias Y; Moritz, Robin Fa; Kraus, F Bernhard
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.
Chandrasekhar, N.; Vinay, S. P.
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.
Mendoza-Hernández, Pedro E.; Rosete-Rodríguez, Alejandra; Sánchez-Coronado, María E.; Orozco, Susana; Pedrero-López, Luis; Méndez, Ignacio; Orozco-Segovia, Alma
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.
Mendoza-Hernández, Pedro E; Rosete-Rodríguez, Alejandra; Sánchez-Coronado, María E; Orozco, Susana; Pedrero-López, Luis; Méndez, Ignacio; Orozco-Segovia, Alma
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.
Sánchez, Daniel; Kraus, F. Bernhard; Hernández, Manuel De Jesús; Vandame, Rémy
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.
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.
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.
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Vigueras, G; Paredes-Hernández, D; Revah, S; Valenzuela, J; Olivares-Hernández, R; Le Borgne, S
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.
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Ulloa, Jerónimo L; Spina, Renata; Casasco, Agustina; Petray, Patricia B; Martino, Virginia; Sosa, Miguel A; Frank, Fernanda M; Muschietti, Liliana V
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
Mueller, Matthias Y; Moritz, Robin FA; Kraus, F Bernhard
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
Montoya, L; Haug, I; Bandala, V M
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.
Ramos, Antero; Bandala, Victor M.; Montoya, Leticia
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
Palanikumar, Pandi; Daffni Benitta, Dani Joel; Lelin, Chinnadurai; Thirumalaikumar, Eswaramoorthy; Michaelbabu, Mariavincent; Citarasu, Thavasimuthu
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
Simoes-Pires, Claudia; Hostettmann, Kurt; Haouala, Amina; Cuendet, Muriel; Falquet, Jacques; Graz, Bertrand; Christen, Philippe
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
Simoes-Pires, Claudia; Hostettmann, Kurt; Haouala, Amina; Cuendet, Muriel; Falquet, Jacques; Graz, Bertrand; Christen, Philippe
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.
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.
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
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.
Gómez-Escobar, Enoc; Liedo, Pablo; Montoya, Pablo; Méndez-Villarreal, Agustín; Guzmán, Miguel; Vandame, Rémy; Sánchez, Daniel
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.
Mottram, J C; McCready, B P; Brown, K G; Grant, K M
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.
Gupta, Sakshi; Singh, Nirmal; Jaggi, Amteshwar Singh
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.
Mullin, Kylie A.; Foth, Bernardo J.; Ilgoutz, Steven C.; Callaghan, Judy M.; Zawadzki, Jody L.; McFadden, Geoffrey I.; McConville, Malcolm J.
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
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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.
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Torres-Peimbert, Silvia; Allen, Christine
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
Schulz-Mirbach, Tanja; Riesch, Rüdiger; García de León, Francisco J; Plath, Martin
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 Â© 2011 Elsevier GmbH. All rights reserved.
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
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.
Estrada-Reyes, Rosa; López-Rubalcava, C; Ferreyra-Cruz, Octavio Alberto; Dorantes-Barrón, Ana María; Heinze, G; Moreno Aguilar, Julia; Martínez-Vázquez, Mariano
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.
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Díaz-Gandarilla, J. A.; Osorio-Trujillo, C.; Hernández-Ramírez, V. I.; Talamás-Rohana, P.
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
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
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).
Montoya, Leticia; Bandala, Victor Manuel; Haug, Ingeborg; Stubbe, Dirk
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.
Collins, H L; Schaible, U E; Ernst, J D; Russell, D G
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.
Garay-Serrano, Edith; Bandala, Victor Manuel; Montoya, Leticia
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.
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
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.
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
34 p. 111. For a fuller treatment, see Olga Pellicer de Brody, "El Ilamado a las Inversiones extranjeras, 1953-1958," In Las Empresas Transnaclonales en ...Development, Hewlett-Packard, 27 February 1987. See also Steve Frazier, "Apple y Hewlett-Packard Contra una Empresa 100% de IBM en Mexico," Excelsior, 27...Heraldo. See "IBM Piensa Crear en Mexico una Planta de Microcomputadoras," El Heraldo, 22 January 1985. 125. Orme, ibid. 126. ibid. 127. It is just as
Mou, Jiaojiao; Wang, Cong; Li, Wenjing; Yang, Jie
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.
Hernández-Chinea, Concepción; Carbajo, Erika; Sojo, Felipe; Arvelo, Francisco; Kouznetsov, Vladimir V; Romero-Bohórquez, Arnold R; Romero, Pedro J
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.
Khamparia, Shraddha; Jaspal, Dipika
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.
Cajimat, Maria N. B.; Milazzo, Mary Louise; Borchert, Jeff N.; Abbott, Ken D.; Bradley, Robert D.; Fulhorst, Charles F.
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
Joshi, Manju B.; Rogers, Matthew E.; Shakarian, Alison M.; Yamage, Mat; Al-Harthi, Saeed A.; Bates, Paul A.; Dwyer, Dennis M.
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
Dagger, Francehuli; Bengio, Camila; Martinez, Angel; Ayesta, Carlos
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.
Murillo-López, Sandra; Venegas-Martínez, Francisco
Resumen Objetivos: obtener estimaciones de indicadores de cobertura de las pensiones por jubilación o retiro para la población mexicana de 65 y más años, y evaluar el impacto que tienen los sistemas de pensiones en las transiciones al retiro de los adultos en edades medias y avanzadas en México. Para ello se utilizan datos microeconómicos provenientes de la Encuesta Nacional de Salud y Envejecimiento. Mediante análisis econométrico se identifican los factores sociodemográficos, económicos, laborales e institucionales que están asociados al acceso a una pensión de jubilación, o bien, a la dependencia de otras fuentes de ingresos. Se encontró que, en México, las transiciones al retiro del mercado de trabajo en las etapas avanzadas del ciclo de vida son limitadas debido a las características eminentemente contributivas de los esquemas de pensiones, los cuales favorecen a la población con trayectorias laborales formales y más estables asociadas a: características de género, oportunidades educativas y posibilidades de inserción en el mercado laboral. PMID:27524936
Allen, C.; Torres-Peimbert, S.
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.
Marimon, Rita; Cano, Josep; Gené, Josepa; Sutton, Deanna A.; Kawasaki, Masako; Guarro, Josep
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
Franco-Díaz, Karen Lizbeth; Fernández-Niño, Julián Alfredo; Astudillo-García, Claudia Iveth
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.
Lu, Xiang; Yang, Lei; Yu, Mengyuan; Lai, Jianbin; Wang, Chao; McNeil, David; Zhou, Meixue; Yang, Chengwei
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.
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
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.
Bierbach, David; Riesch, Rüdiger; Schießl, Angela; Wigh, Adriana; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Klaus, Sebastian; Zimmer, Claudia; Plath, Martin
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
Jourdan, Jonas; Bierbach, David; Riesch, Rüdiger; Schießl, Angela; Wigh, Adriana; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Klaus, Sebastian; Zimmer, Claudia; Plath, Martin
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.
Hernández-Abreu, Oswaldo; Durán-Gómez, Liliana; Best-Brown, Roberto; Villalobos-Molina, Rafael; Rivera-Leyva, Julio; Estrada-Soto, Samuel
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.
... de Aeronautica S.A. (EMBRAER) Model ERJ 190 Airplanes AGENCY: Federal Aviation Administration (FAA... the failure occurred due to hydrogen embrittlement. The ANAC [Ag[ecirc]ncia Nacional de Avia[ccedil.... For service information identified in this proposed AD, contact Empresa Brasileira de Aeronautica S.A...
... de Aeronautica S.A. (EMBRAER) Model EMB-500 Airplanes AGENCY: Federal Aviation Administration (FAA... proposed AD. Discussion The AG[Ecirc]NCIA NACIONAL DE AVIA[Ccedil][Atilde]O CIVIL--BRAZIL, which is the... MCAI in the AD docket. Relevant Service Information Empresa Brasileira de Aeron[aacute]utica S.A...
Riesch, Rüdiger; Reznick, David N; Plath, Martin; Schlupp, Ingo
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.
Riesch, Rüdiger; Reznick, David N.; Plath, Martin; Schlupp, Ingo
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
Guzmán-Cornejo, C; García-Prieto, L; Morales-Malacara, J B; Pérez-Ponce De León, G
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.
... de Aeronautica S.A. (EMBRAER) Model ERJ 170 and ERJ 190 Airplanes AGENCY: Federal Aviation..., contact Empresa Brasileira de Aeronautica S.A. (EMBRAER), Technical Publications Section (PC 060), Av... receive about this proposed AD. Discussion The Ag[ecirc]ncia Nacional de Avia[ccedil][atilde]o Civil (ANAC...
Flores Carmona, Judith
I am an assistant professor at New Mexico State University; however, the path to getting to this position has been about crossing borders, about learning in and from the borderlands. The borderlands that my body has had to cross, physically and figuratively, have left many "heridas abiertas" (open wounds) but have also provided me with…
Jamal, Salma; Scaria, Vinod
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.
Rodriguez-Contreras, Dayana; Hamilton, Nicklas
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.
Riesch, Rüdiger; Plath, Martin; Schlupp, Ingo
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.
Walker, Janiece L.; Harrison, Tracie C.; Hendrickson, Sherry G.
There is a dearth of literature examining how adversity shapes the experiences of pain and/or suffering in a middle aged Mexican American women. The purpose of this qualitative descriptive study was to understand pain and suffering from a life course perspective as described by a Mexican American woman aging with early onset mobility impairment. This Hispanic woman experienced episodes of abuse and rejection over the life course, which may have significantly influenced her pain and suffering experience in adulthood. This adds to the literature on how adversity influences later life pain experience and provides insight on why pharmacological treatment alone may not be as successful as a holistic intervention. Hay escasez de literatura que examine cómo la adversidad da forma a las experiencias de dolor y / o sufrimiento en mujeres mexicana-americana mayores de edad. El propósito de este estudio descriptivo cualitativo fue comprender el dolor y el sufrimiento desde una perspectiva de ciclo de vida como descrito por una mujer mexicana-americana envejeciendo con inicio temprano de deterioro de movilidad. Esta Latina experimentó episodios de maltrato y rechazo, que se percibió haber afectado su experiencia de dolor y sufrimiento luego como adulta. Este estudio aumenta la literatura sobre cómo la adversidad influya la experiencia de dolor más tarde en la vida, y nos permite comprender mejor como el tratamiento farmacológico por sí solo no es tan exitoso como pueda ser una intervención integral. PMID:24830728
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
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.
Tobler, Michael; Dewitt, Thomas J; Schlupp, Ingo; García de León, Francisco J; Herrmann, Roger; Feulner, Philine G D; Tiedemann, Ralph; Plath, Martin
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.
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Sánchez, D; Solórzano-Gordillo, E; Vandame, R
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.
Zimmer, Claudia; Bierbach, David; Arias-Rodriguez, Lenin; Plath, Martin
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
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
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
Scala, Angela; Rescifina, Antonio; Micale, Nicola; Piperno, Anna; Schirmeister, Tanja; Maes, Louis; Grassi, Giovanni
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.
Corrales, Adriana; Arnold, A Elizabeth; Ferrer, Astrid; Turner, Benjamin L; Dalling, James W
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.
Graz, Bertrand; Willcox, Merlin L; Diakite, Chiaka; Falquet, Jacques; Dackuo, Florent; Sidibe, Oumar; Giani, Sergio; Diallo, Drissa
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 (there were no cases in patients 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.
Cárdenas-Rodríguez, Noemí; González-Trujano, María Eva; Aguirre-Hernández, Eva; Ruíz-García, Matilde; Sampieri, Aristides; Coballase-Urrutia, Elvia; Carmona-Aparicio, Liliana
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
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
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.
Kukula-Koch, Wirginia; Mroczek, Tomasz
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%.
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
El consentimiento informado es un proceso, en el que una persona acepta participar en una investigation, conociendo los riesgos, beneficios, consecuencias o problemas que se puedan presenter durante el desarrollo de la misma. El objetivo de este trabajo es reunir las caracteristicas del proceso de consentimiento informado (PCI) pare que su discernimiento y cumplimiento posibilite el ejercicio etc° dialogico, reflexivo y responsable del investigador. Se presentan los resultados de una extensa revision de les elementos del PCI, desde sus cornponentes hasta su fundamento etico y legal, incluyendo los mites y realidades que existen sobre el formato de consentimiento informado come recurso legal de protection. El consentimiento informado no es un formato establecido que los investigadores repliquen, se trata de que la praxis del PCI sea una tarea cotidiana dentro de la investigation con seres humanos, como comunicaciOn deliberative y critica, responsable y comprometida entre dos agentes morales, investigador-investigado. PMID:19507477
En este trabajo se presenta una muy breve introducción al concepto de Entropía de la Información y se muestran distintas aplicaciones de una misma técnica para estudiar problemas tan variados como la determinación de periodicidad en una serie de tiempo arbitraria o de estimar el grado de caoticidad de una trayectoria en un sistema dinámico de N grados de libertad.
Hernández, Rosaura Pérez; Thrasher, James F.; Bolaños, Rosibel Rodríguez; Gutiérrez, Inti Barrientos; Hernández, Norma A Ibañez
Resumen Objetivo Determinar en población fumadora el nivel de exposición a la mercadotecnia por parte de la Industria Tabacalera (IT), a través de diferentes métodos de promocionar sus productos de tabaco, antes y durante la publicación de la Ley General para el Control del Tabaco (LGCT) en 2008. Material y métodos Estudio de cohorte en fumadores adultos (n=941 pre-LGCT y n=1051 post-LGCT) de cuatro ciudades mexicanas. Se realizaron análisis multivariados mediante modelos de ecuaciones de estimación generalizada (GEE). Resultados Se incremento el autoreporte de recepción de muestras gratis de cigarros (3.7% a 8.1%), ropa o artículos con marcas o logos (3.6% a 6.4%), haber visto información sobre eventos especiales (1.9% a 4.7%), y bares, antros y discos para mayores de edad (21.4% a 28%). Se observaron decrementos de publicidad en exteriores (54.7% a 47.2%). Conclusión Es necesaria una política integral con prohibiciones totales de la publicidad y promoción de los productos de tabaco que integre mayor vigilancia y sanciones para lograr la disminución y prevención del consumo de tabaco. PMID:22689158
Jones, Ian M; Koptur, Suzanne
• 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.
Silvia, Mejía-Arango; Clemente, y Zúñiga-Gil
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
Jimenez, T.; Olson, K.
Esta es la primera de una serie de guias de aplicaciones que el Programa de Energia de Villas de NREL esta comisionando para acoplar sistemas comerciales renovables con aplicaciones rurales, incluyendo agua, escuelas rurales y micro empresas. La guia esta complementada por las actividades de desarrollo del Programa de Energia de Villas de NREL, proyectos pilotos internacionales y programas de visitas profesionales.
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
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
Fiebig, Michael; Kelly, Steven; Gluenz, Eva
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
La idea sobre una reunión latino-americana que congregara a las personas que desarrollan su trabajo en el área de la astrometría, se gestó a partir de una de las reuniones que el proyecto QUEST realizaba anualmente en Mérida (Venezuela). El proyecto QUEST (Quasars Equatorial Survey Team) celebraba su IV Reunión Anual, en la cual se hacía una revisón de la marcha del proyecto durante el último año. Además, se exponían los logros científicos y técnicos alcanzados hasta el momento y se planificaba el futuro del mismo para el período anual siguiente.
Sánchez-Recillas, Amanda; Mantecón-Reyes, Paul; Castillo-España, Patricia; Villalobos-Molina, Rafael; Ibarra-Barajas, Maximiliano; Estrada-Soto, Samuel
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.
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
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.
Jones, Ian M; Koptur, Suzanne
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.
Plath, Martin; Tobler, Michael; Riesch, Rüdiger; García de León, Francisco J.; Giere, Olav; Schlupp, Ingo
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.
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
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.
Ramos Pastrana, Nilsa
investigacion se utilizo una metodologia cuantitativa y la herramienta para lograrlo fue una encuesta. La encuesta se analizo estadisticamente mediante analisis de frecuencias y por cientos, prueba ANOVA, prueba t, pruebas Post Hoc de Tukey y de Levene. Tambien se realizo nuevamente una prueba de confiabilidad mediante el alfa de Cronbach. Los resultados reflejaron que los profesores de las Facultades de Administracion de Empresas, Ciencias Sociales, Ciencias Naturales, Educacion, Humanidades, Estudios Generales y el Departamento de Ciencias Biologicas tienen una percepcion muy positiva del concepto de cultura cientifica, los contenidos curriculares de Ciencias Biologicas y del nuevo bachillerato.
Plath, M; Hauswaldt, J S; Moll, K; Tobler, M; García De León, F J; Schlupp, I; Tiedemann, R
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.
Hufford, Matthew B.; Lubinksy, Pesach; Pyhäjärvi, Tanja; Devengenzo, Michael T.; Ellstrand, Norman C.; Ross-Ibarra, Jeffrey
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
Crespo, N; Sánchez-Murcia, P A; Gago, F; Cejudo-Sanches, J; Galmes, M A; Fernández-Lucas, Jesús; Mancheño, José Miguel
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.
Grunert, Patrick; Rosenthal, Yair; Jorissen, Frans; Holbourn, Ann; Zhou, Xiaoli; Piller, Werner E.
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.
Katz, Aron D
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.
Cornejo, Susana; Herrera, Ariel; Hilas, Elena; Gigena, Y Pablo
El capital social supone importantes inversiones materiales, simbólicas y de esfuerzos. Conocer el capital social de una comunidad puede facilitar la comprensión del beneficio de las relaciones comunitarias para la promoción de salud. Con el objetivo de reconocer los componentes del capital social de padres de escolares atendiendo una escuela en una zona vulnerable de la ciudad de Córdoba, Argentina, indagamos a través de grupos focales acerca de elementos esenciales del capital social. La asintonía socio-cultural entre los pobladores originarios y los reubicados, la estigmatización policial y el clientelismo político han generado desconfianza del uno hacia el otro en diferentes aspectos convivenciales, siendo la familia la única red de apoyo. La escuela se reconoce como espacio adonde la gente espontáneamente se organiza para invertir en redes sociales, presentándose así con potencialidad para la promoción de conductas saludables, por el lugar simbólico que ocupa para los padres.
Nebraska State Historical Society, Lincoln.
This publication is intended as a resource guide for teachers, students, and librarians interested in Mexican American culture, and for groups wishing to conduct local community research using oral histories. The Mexican American Traditions in Nebraska project was designed to document and preserve the richness of Nebraska's Mexican culture. The…
Arnal, E. M.
Los estudios llevados a cabo en la transición del hidrógeno neutro a λ~21-cm han contribuído a incrementar nuestro conocimiento acerca de las propiedades globales del medio interestelar, sea este galáctico o extragaláctico. Avances en este campo han sido provocados, a menudo, por la puesta en servicio de radiotelescopios que poseen una mayor resolución angular. Aquí se presenta una propuesta para desarrollar un nuevo instrumento, un interferómetro, que permitirá abrir nuevas líneas de investigación. Este instrumento combinará la técnica de síntesis de apertura con la de espectroscopía de correlación digital, para alcanzar una resolución angular de 1' y un campo de visión de ~1o.7.
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
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
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
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
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.
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
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
Montenegro, Hector; Gutiérrez, Marcelino; Romero, Luz I; Ortega-Barría, Eduardo; Capson, Todd L; Rios, Luis Cubilla
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.
Niemela, V.; Morrell, N.; Corti, M.
En este trabajo presentamos un nuevo análisis orbital de LSS~3074, junto con tipos espectrales y velocidades radiales de estrellas que podrían constituir con ella una nueva asociación OB. La estrella O4f LSS3074 fue descubierta como binaria espectroscópica de corto período y líneas dobles por Morrell & Niemela (1990, ASP Conf. Ser. 7, 57). Posteriormente, Haefner et~al.(1994, IBVS 3969) encontraron variaciones fotométricas, estimando una inclinación orbital entre 50o y 55o. Teniendo en cuenta la importancia de obtener valores empíricos para las masas de estrellas O tempranas, y considerando la gran dispersión existente entre los valores observados y su discrepancia con los predichos por los modelos teóricos, hemos obtenido nuevas observaciones espectroscópicas de este sistema, con el propósito de mejorar los elementos orbitales derivados en la solución preliminar. Además, como las estrellas O tempranas suelen formar parte de cúmulos y asociaciones OB, hemos llevado a cabo una investigación espectroscópica de varias estrellas tempranas que podrían estar físicamente relacionadas con LSS~3074.
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.
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
Kipp, Evan J; Mariscal, Jacqueline; Armijos, Rodrigo X; Weigel, Margaret; Waldrup, Kenneth
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
Berger, I; Passreiter, C M; Cáceres, A; Kubelka, W
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.
Rendon, Laura I.
This essay focuses on the need to educate the new "persona educada", a dignified, honorable person with a good measure of social and personal responsibility who also possesses the habits of the mind and heart. To cultivate "una persona educada" requires a newly formed vision of education and pedagogy. Examples of three entrenched agreements that…
The existence of the celestial bodies is known due to the light they emit. But light is a small part of a bigger phenomenon known as electromagnetic radiation. The representation of all kinds of electromagnetic radiation as a function of its frequency is called the electromagnetic spectrum. If we only studied the visible part of the spectrum, we would ignore a great deal of information. The celestial bodies emit radiation in all the regions of the electromagnetic spectrum, with very different intensity. To capture these data, astronomers design new types of telescopes that capture radiation at different wavelengths, among them the radiotelescopes that, as the name indicates, detect radio waves. The radiotelescope can be compared to a regular radio set. A radio station sends information by means of radio waves. The radio set captures these waves by means of its antenna, processes it and reproduces the information (music, etc.) in audible form. In the field of radioastronomy, interesting observations can be carried out: radio emission from stars, nebulas, pulsars, distant galaxies and stars, radiogalaxies, the Milky Way, the Sun, Jupiter, etc. La presencia de los cuerpos celestes se conoce gracias a que emiten luz. Pero la luz constituye solo una pequeña parte de un fenómeno mucho mas amplio conocido como radiación electromagnética. La representación de todas las clases de radiación como función de su frecuencia se denomina espectro electromagnético. Si solo estudiáramos la parte visual del espectro ignoraríamos una gran cantidad de información. Los cuerpos celestes emiten radiación en todas las regiones del espectro electromagnético, aunque con muy distinta intensidad. Para captar estos datos, los astrónomos deben diseñar nuevos tipos de telescopios que puedan captar la radiación de distintas longitudes de ondas, entre ellos los radiotelescopios, qué como su nombre lo indica detectan ondas de radio. El radiotelescopio puede compararse a un aparato
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
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.
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
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.
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
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.
Van Hellemond, Jaap J.; Opperdoes, Fred R.; Tielens, Aloysius G. M.
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
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
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
Martín-Quintal, Zhelmy; del Rosario García-Miss, María; Mut-Martín, Mirza; Matus-Moo, Abril; Torres-Tapia, Luis W; Peraza-Sánchez, Sergio R
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.
Burgos, Rubén; Aguilar-Salinas, Carlos Alberto; Barile-Fabris, Leonor; Rangel-Fraustro, Manuel Sigfrido; Arrieta, Óscar; Campillo, Carlos; Celis, Miguel Ángel; Llata, Manuel de la; Domínguez, Judith; Halabe, José; Islas, Sergio; Jasso, Luis; Lifshitz, Alberto; Moreno, Mucio; Plancarte, Ricardo; Reyes, Alejandro; Soda, Antonio; Verástegui, Emma; Sotelo, Julio
La relación que involucra al médico y la industria abarca un espectro amplio de formas, para lo cual se requiere una exposición clara y transparente de términos y principios. Uno de los objetivos primordiales de la industria es contar con un respaldo académico que le permita dar a conocer las características y las propiedades de sus productos -eficacia, eficiencia y seguridad- con el propósito de ser prescritos y usados. Los fines de la industria son la venta de sus productos, el reconocimiento como empresas de prestigio y la ganancia económica. Implícitamente, para CETREMI el principio de mayor importancia en esta relación es indudablemente el beneficio del enfermo.
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
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
Schulz-Mirbach, Tanja; Heß, Martin; Plath, Martin
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
After a brief introduction to the topic the paper first gives an overview of Kilivila landscape terms and then presents the inventory of names for villages, wells, island points, reef-channels and gardens on Kaile'una Island, one of the Trobriand Islands in the Milne Bay Province of Papua New Guinea. The data on the meaning of the place names…
Gómez-Escobar, Enoc; Liedo, Pablo; Montoya, Pablo; Vandame, Rémy; Sánchez, Daniel
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.
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…
Yeh, Johannes T.-H.; Nam, Kwangho; Yeh, Joshua T.-H.; Perrimon, Norbert
The absorption, distribution, metabolism and excretion (ADME) of metabolites and toxic organic solutes are orchestrated by the ATP-binding cassette (ABC) transporters and the organic solute carrier family (SLC) proteins. A large number of ABC and SLC transpoters exist; however, only a small number have been well characterized. To facilitate the analysis of these transporters, which is important for drug safety and physiological studies, we developed a sensitive genetically encoded bilirubin (BR)-inducible fluorescence sensor (eUnaG) to detect transporter-coupled influx/efflux of organic compounds. This sensor can be used in live cells to measure transporter activity, as excretion of BR depends on ABC and SLC transporters. Applying eUnaG in functional RNAi screens, we characterize l(2)03659 as a Drosophila multidrug resistant-associated ABC transporter. PMID:28176814
Socolovsky, Mariano; Di Masi, Gilda; Binaghi, Daniela; Campero, Álvaro; Páez, Miguel Domínguez; Dubrovsky, Alberto
Introducción: El síndrome de outlet torácico es una compresión del plexo braquial que suscita polémica. Se clasifica en Outlet Torácico Verdadero o neurogénico (OTV) y Outlet Torácico Disputado o no neurogénico (OTD). El primero presenta síntomas motores en la mano, mientras que el segundo sólo síntomas sensitivos en el miembro superior. El objetivo de este trabajo es analizar los resultados obtenidos en una serie de 31 cirugías. Métodos: Se analizaron las cirugías de nervios efectuadas entre 2003-2012, tomando los diagnósticos de outlet torácico cuyo período de seguimiento post-operatorio mínimo fuera de 6 meses. Se buscaron los siguientes datos: edad, sexo, presencia de síntomas sensitivos y/o motores, clasificación, resultado de los estudios neurofisiológicos y de imágenes, resultado de la cirugía, complicaciones post-operatorias y recidivas. Resultados: Se incluyeron 31 cirugías realizadas en 30 pacientes, 9 OTV (8 mujeres) de 24.3 años, y 21 con OTD (18 mujeres) de 37.4 años de edad en promedio. Un 90% presentaron alteraciones neurofisiológicas preoperatorias, y 66,6% imagenológicas. En el intraoperatorio, el 100% de los OTV presentó una alteración anatómica relacionada con la sintomatología, hecho observado sólo en el 36.7% de los OTD operados. El 87,5% de los OTV mejoraron sensitivamente, mientras que 77,7% mejoraron la atrofia. Por el contrario, 45.4% de los OTD mejoraron permanentemente, 36.3% no tuvieron cambios, 13.6% mejoraron transitoriamente y 4.5% (un caso) empeoró. Las complicaciones post-operatorias fueron más frecuentes aunque transitorias en el grupo de OTV (3 casos sobre 9 operados, 33.3%) que en los OTD (3 casos sobre 22, un 13.6%). Conclusión: El OTV suele mayormente mejorar luego de la cirugía, igual que el OTD aunque en una proporción mucho menor. Estos hallazgos coinciden con otros reportes recientes de esta patología. PMID:25165614
Goldschmidt, Ezequiel; Ajler, Pablo; Campero, Álvaro; Landriel, Federico; Sposito, Maximiliano; Carrizo, Antonio
Introducción: los meningiomas del foramen óptico producen un rápido deterioro de la función visual aún cuando su tamaño es pequeño, por eso su diagnóstico y manejo difiere del resto de los meningiomas clinoideos. El propósito de este estudio es presentar la técnica y los resultados de nuestro manejo quirúrgico de meningiomas foraminales (MF). Pacientes y Métodos: se llevó a cabo una revisión de las historias clínicas de 47 pacientes con meningiomas primarios intraorbitarios. Se realizaron 52 cirugías en los pacientes con MF. Se empleó una craneotomía fronto-orbitaria, seguida de una descompresión extradural del canal óptico, resección del componente intraorbitario y exploración intradural del nervio óptico. Resultados: de los 12 pacientes con MF que presentaban la visión conservada, la agudeza visual fue preservada en 7 casos, mejoró en 2, y empeoró en 3. En 18 pacientes, el principal síntoma fue exoftalmos y en 35 pacientes ceguera unilateral. Ocurrieron 6 recurrencias, 2 a 10 años después de la resección quirúrgica. Cinco de ellos fueron reoperados. Se indicó radioterapia después de la recurrencia en 3 pacientes. Conclusión: el manejo de los MF continúa siendo controvertido y frecuentemente se propone un tratamiento conservador. Basados en nuestros hallazgos de frecuente extensión intracraneal, proponemos realizar una resección total o subtotal del tumor, preservando el nervio óptico en pacientes con visión prequirúrgica conservada. PMID:25165616
Parfitt, Dan E.; Badenes, Maria L.
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
Tobler, Michael; Schlupp, Ingo; Heubel, Katja U; Riesch, Rüdiger; de León, Francisco J García; Giere, Olav; Plath, Martin
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.
de León González, Enrique Díaz; Pérez, Héctor Eloy Tamez; Hermosillo, Hugo Gutiérrez; Rodríguez, Javier Armando Cedillo; Torres, Gabriela
Fundamento y objetivo Determinar la asociación entre fragilidad y mortalidad, dependencia funcional, caídas y hospitalizaciones en el Estudio Nacional de Salud y Envejecimiento en México (ENASEM). Sujetos y métodos Estudio prospectivo poblacional en México en el que se seleccionaron sujetos de 60 años o más, que fueron evaluados en las variables de fragilidad durante la primera vuelta del estudio en el año 2001 y que incluyó: dificultad para levantarse de una silla después de haber estado sentado(a) durante largo tiempo, pérdida de peso de 5 kilogramos o más en los últimos dos años y falta de energía. Los sujetos fueron catalogados como robustos, prefrágiles y frágiles cuando tenían cero, una o dos de las características anteriores, respectivamente. La mortalidad, hospitalizaciones, caídas y dependencia funcional fueron evaluadas en la segunda vuelta del estudio en el año 2003. Se calculó el riesgo relativo para cada una de las complicaciones, así como análisis multivariado con regresión de Cox para el caso de mortalidad y regresión logística para el resto. Resultados Los estados de prefragilidad y fragilidad se asociaron independientemente con mortalidad, con índices de riesgo ajustados de 1,61 (intervalo de confianza del 95% [IC 95%] 1,01-2,55) y 1,94 (IC 95% 1,20-3,13), respectivamente. Sólo el estado de fragilidad se asoció independientemente con hospitalización y dependencia funcional, con una razón de momios ajustada de 1,53 (IC 95% 1,13-2,07) y 3,07 (IC 95% 1,76-5,34), respectivamente. No hubo asociación entre los estados de prefragilidad y fragilidad con caídas. Conclusión El estado de fragilidad se asocia independientemente con mortalidad, hospitalizaciones y disfuncionalidad en actividades básicas de la vida diaria en los siguientes dos años en población mexicana. PMID:21612803
Padilla-Jacobo, Gabriela; Cano-Camacho, Horacio; López-Zavala, Rigoberto; Cornejo-Pérez, María E; Zavala-Páramo, María G
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
Este artículo intenta contestar tres preguntas. Sobre el pasado: ¿Por qué no existió una epidemiología precolombina? Sobre el presente: ¿Cuáles son los orígenes de la epidemiología moderna, incluyendo sus raíces sudamericanas? Y sobre el futuro, escogí un título surrealista para enfatizar el hecho que estoy consciente de que es siempre delicado hacer predicciones: ¿Por qué fenómenos complejos son los “objetos oscuros del deseo” epidemiológico? PMID:25124247
... 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...
Bierbach, David; Schulte, Matthias; Herrmann, Nina; Zimmer, Claudia; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Riesch, Rüdiger; Plath, Martin
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
Bierbach, David; Schulte, Matthias; Herrmann, Nina; Zimmer, Claudia; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Riesch, Rüdiger; Plath, Martin
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.
Woodman, Neal; Stephens, Ryan B.
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.
Cano, Luz Helena; Acosta, María Natalia; Pulido, Adriana
Introducción. La detección temprana del riesgo de problemas emocionales y del comportamiento en niños puede contribuir al desarrollo de estrategias que promuevan la salud mental desde la primera infancia. En Colombia no existe una herramienta validada para dicha detección.Objetivos. Seleccionar, adaptar y establecer la validez de criterio de una escala de tamización de problemas emocionales y del comportamiento en niños menores de seis años.Materiales y métodos. A partir de una revisión de la literatura y un consenso de expertos, se seleccionó la herramienta Early Childhood Screening Assessment (ECSA). Posteriormente, se llevó a cabo su adaptación lingüística y se determinó la validez de criterio mediante una curva de características de recibidor-operador (Receiver Operating Characteristic, ROC), y se la comparó con el cuestionario Child Behavior Checklist (CBCL 1,5-5). En el estudio participaron 206 cuidadores de niños entre el año y medio y los seis años de edad de la ciudad de Tunja y el municipio de Sopó.Resultados. La puntuación del ECSA presentó una buena correlación con la puntuación t total del CBCL 1,5-5 (ro de Spearman=0,75; p<0,01). La escala ECSA tuvo una sensibilidad de 86 % y una especificidad de 82 % al establecer un punto de corte de 24 para la población estudiada.Conclusión. En este primer estudio de adaptación y validación de la versión en español de la escala ECSA, se detectaron buenos valores de sensibilidad y especificidad para la tamización de problemas emocionales y del comportamiento en la primera infancia.
Prakasam, D. C., Jr.; Zaman, B.
Water is one of the most vital natural resource and its availability and quality determine ecosystem productivity, both for agricultural and natural systems. Una district is one of the major potential agricultural districts in Himachal Pradesh, India. More than 70% of the population of this district is engaged in agriculture and allied sectors and major crops grown are maize, wheat, rice, sugarcane, pulses and vegetables. The region faces drought every year and about 90 per cent of the area is water stressed. This has resulted in crop loss and shortage of food and fodder. The sources of drinking water, small ponds and bowlies dry-up during summer season resulting in scarcity of drinking water. Una district receives rainfall during monsoons from June to September and also during non-monsoon period (winter). The annual average rainfall in the area is about 1040 mm with 55 average rainy days. But due to heavy surface run-off the farmers not able to cultivate the crops more than once in a year. Past research indicate that the geomorphology of the Una district might be responsible for such droughts as it controls the surface as well as ground water resources. The research proposes to develop a water stress model for Una district using the geomorphic parameters, water resource and land use land cover data of the study area. Using Survey of India topographical maps (1:50000), the geomorphic parameters are extracted. The spatial layers of these parameters i.e. drainage density, slope, relative relief, ruggedness index, surface water body's frequency are created in GIS. A time series of normalized remotely sensed data of the study area is used for land use land cover classification and analyses. Based on the results from the water stress model, the drought/water stress areas and water harvesting zones are identified and documented. The results of this research will help the general population in resolving the drinking water problem to a certain extent and also the
Tobler, Michael; Franssen, Courtney M; Plath, Martin
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.
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...
Rodriguez Ramos, Teresita
Se llevó a cabo una investigación en acción con los propósitos de 1) documentar las relaciones de las tecnologías de la información y la comunicación en las clases de ciencias de escuela intermedia como elemento de apoyo cuando se aborda el tema ambiental y sus conceptos pertinentes, a partir de las observaciones de la investigadora, así como las entrevistas y diarios reflexivos de los estudiantes de una escuela intermedia en la zona metropolitana, y luego 2) diseñar una unidad instruccional sobre el tema ambiental que integre actividades tecnologías para el curso de ciencias de la escuela intermedia según el modelo PROCIC y las observaciones que hayan iniciado los estudiantes participantes. Finalmente, se plantearon las implicaciones educativas para el currículo del Programa de Ciencias al instrumentar este modelo de unidad mediante PROCIC, e integrado la tecnología y el tema ambiental. Los hallazgos se analizaron y se categorizaron de acuerdo con las preguntas de investigación. El hallazgo principal de la investigación aborda las cuatro relaciones centrales en las que se articula la utilización de las tecnologías y sus aplicaciones en la clase de ciencias. Estas cuatro relaciones que recogen la posición de los estudiantes son: 1) Perspectiva de los estudiantes hacia la tecnología. 2) Participación de los estudiantes en los aspectos docentes. 3) Aprendizaje estudiantil sobre el ambiente, y 4) Conciencia ambiental en relación con la vida diaria. Estas relaciones ponen de manifiesto,cómo se plantea en las implicaciones, la necesidad de más investigación en acción en la sala de clases, la importancia—como tema transversal—de la conciencia ambiental mediante la tecnología al construir conocimientos significativos dentro y fuera de la escuela, asó como, valorar la investigación y la dialogicidad en la sala de clases como actividades que obligan al reexamen de la práctica didáctica en su formas curriculares de objetivos, recursos
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...
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.
Robert R. Kula; Kathleen S. Knight; Joanne Rebbeck; Leah S. Bauer; David L. Cappaert; Kamal J.K. Gandhi
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...
Gamboa-Leon, Rubi; Vera-Ku, Marina; Peraza-Sanchez, Sergio R.; Ku-Chulim, Carlos; Horta-Baas, Aurelio; Rosado-Vallado, Miguel
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
Campollo-Ovalle, A; Sánchez, D
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.
Khamparia, Shraddha; Jaspal, Dipika
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.
Gerald E. Rehfeldt
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...
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...
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.
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
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.
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.
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
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.
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.
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
Victoria A. Saab; Robin E. Russell; Jonathan G. Dudley
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...
F. Thomas Ledig; Paul D. Hodgskiss; Konstanin V. Krutovskii; David B. Neale; Teobaldo Eguiluz-Piedra
Numerous populations from six spruce taxa, including four relict endemics, Picea chihuahuana (Chihuahua spruce), P. martinezii (MartÃnez spruce), P. mexicana (Mexican spruce), and P. breweriana (Brewer spruce), and two widespread species, P. engelmannii (Engelmann spruce) and...
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
against drugs is not 191 Nelson Jobim, interview by Empresa Brasil de Comunicação Radio, trans. Open Source Center, February 6, 2009, available from... Empresa Brasil de Comunicação Radio, trans. Open Source Center, February 6, 2009, available from http://www.ebc.com.br (accessed February 23, 2009...Institute of Peace, 1996. Jobim, Nelson. Interview by Empresa Brasil de Comunicação Radio. Translated by Open Source Center. February 6, 2009
Litewka, Sergio; Goodman, Kenneth; Braunschweiger, y Paul
El Programa CITI (Collaborative Institutional Training Initiative) es un curso basado en Internet y desarrollado por voluntarios, que brinda material educacional sobre protección de sujetos humanos en investigaciones biomédicas y de conducta, buenas prácticas clínicas, conducta responsable de la investigación y trato humanitario a animales de laboratorio. Es un esfuerzo conjunto del Fred Hutchinson Cancer Research Center y la Universidad de Miami. Con la colaboración de expertos locales, gran parte del contenido se ha adaptado para América Latina, se ha traducido al español y portugués y se han establecido acuerdos de colaboración con instituciones especializadas en bioética en Chile, Brasil, Costa Rica y Perú. Los autores presentan una metodología accesible para la capacitación en ética de la investigación y una justificación de su uso y difusión en América Latina PMID:21687817
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 ...
Kato, Hirotomo; Gomez, Eduardo A; Martini-Robles, Luiggi; Muzzio, Jenny; Velez, Lenin; Calvopiña, Manuel; Romero-Alvarez, Daniel; Mimori, Tatsuyuki; Uezato, Hiroshi; Hashiguchi, Yoshihisa
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.
Gamboa-Leon, Rubi; Vera-Ku, Marina; Peraza-Sanchez, Sergio R; Ku-Chulim, Carlos; Horta-Baas, Aurelio; Rosado-Vallado, Miguel
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.
34Presentation to Asociacion Panamae na de Ejecutivos de Empresa ," Director J.S.A.I.D., Panama, 14 November 1990. 25 CHAPTER VII U.S. MILITARY’S ROLE IN...Asociacion Panamena de Ejecutivos de Empresa ," Director U.S.A.I.D. Panama, 14 November 1990. 13. Ministry of Planning and Economics, p. 39. 14...Thomas W. "Presentation to Asociacion Panamena de Ejecutivos de Empresa ." Directive U.S.A.I.D., Panama 14 November 1990. Summ, G. Harvey and Kelly
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
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...
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
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...
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
Ronnie, Q.; Segura, J.; Burgoa, B.; Jimenez, W.; McNally, K. C.
This work is the result of the analysis of existing information in the earthquake database of the Observatorio Sismológico y Vulcanológico de Costa Rica, Universidad Nacional (OVSICORI-UNA), and seeks disclosure of basic seismological information recorded and processed in 2010. In this year there was a transition between the software used to record, store and locate earthquakes. During the first three months of 2010, we used Earthworm (http://folkworm.ceri.memphis.edu/ew-doc), SEISAN (Haskov y Ottemoller, 1999) and Hypocenter (Lienert y Haskov, 1995) to capture, store and locate the earthquakes, respectively; in April 2010, ANTELOPE (http://www.brtt.com/software.html) start to be used for recording and storing and GENLOC (Fan at al, 2006) and LOCSAT (Bratt and Bache 1988), to locate earthquakes. GENLOC was used for local events and LOCSAT for regional and distant earthquakes. The local earthquakes were located using the 1D velocity model of Quintero and Kissling (2001) and for regional and distant earthquakes IASPEI91 (Kennett and Engdahl, 1991) was used. All the events for 2010 and shown in this work were rechecked by the authors. We located 3903 earthquakes in and around Costa Rica and 746 regional and distant seismic events were recorded (see Figure 1). In this work we also give a summary of major earthquakes recorded and located by OVSICORI-UNA network between 1983 and 2012. Seismicity recorded by OVSICORI-UNA network in 2010
Kato, Hirotomo; Gomez, Eduardo A.; Martini-Robles, Luiggi; Muzzio, Jenny; Velez, Lenin; Calvopiña, Manuel; Romero-Alvarez, Daniel; Mimori, Tatsuyuki; Uezato, Hiroshi; Hashiguchi, Yoshihisa
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
Kato, Hirotomo; Watanabe, Junko; Mendoza Nieto, Iraida; Korenaga, Masataka; Hashiguchi, Yoshihisa
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.
Trinidad Galván, Ruth
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…
Brown, Antoinette B.; Partridge, William L.
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)
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...
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…
Ortiz Benavides, Fedra Lorena
El proposito de la investigacion fue evaluar la efectividad de una actividad de aprendizaje basado en la argumentacion dialogica en linea y su incidencia en el desarrollo de competencias cientificas. Se fundamenta en la teoria del aprendizaje socio cultural de Vigotsky (1984), los principios del diseno instruccional de la cognicion situada por Hung y Der-Thang (2001) y como estrategia se aplico la argumentacion dialogica utilizando el Modelo Argumentativo de Toulmin MAT (1984). El diseno experimental comparo dos grupos de estudiantes A y B en el curso virtual de Biotecnologia. El grupo A (experimental) desarrollo la discusion a partir de la estrategia disenada para este estudio y el grupo B (control) realizo la discusion desde las actividades tradicionales. El desarrollo de la competencia argumentativa se valoro con el instrumento de evaluacion para argumentacion dialogica en linea propuesta por Clark y Sampson (2008). La evaluacion de las competencias cientificas se realizo a partir de una postprueba. Los datos fueron analizados con pruebas estadisticas no parametricas. Los resultados de la investigacion, indicaron diferencias significativas en el nivel de la competencia argumental en el grupo experimental en comparacion al grupo control. Igualmente se demostro que existe una relacion positiva entre el nivel de desarrollo de la competencia argumentativa y el nivel de desarrollo de las competencias cientificas.
Martínez-Ballesté, Andrea; Martorell, Carlos
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.
Martínez-Ballesté, Andrea; Martorell, Carlos
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
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…
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…
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
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
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...
Portillo, Cristina, Comp.; And Others
The 283 materials cited in this bibliography are chiefly on Chicanas in the United States. However, books or articles that discuss Mexicanas or women in general and can be related to the experiences of Chicanas are also cited. Areas covered include the arts, education, sociology, economics, history, health, and literature. The materials are…
Sosa-Provencio, Mia Angélica
Through a Chicana Feminist and Curricular Reconceptualist lens, this article theorizes a Curriculum of the Mestiza/o Body as return to historicized, corporal knowing which takes shape, form, flesh and language in the Mestiza/o Body in order to nourish and arm especially Mexican/Mexican-American (Mexicana/o) young people toward equitable, hopeful…
Institute of International Education, New York, NY.
This document features writings and curriculum projects by teachers who traveled to Mexico and Central America in the summer of 1991 as members of a Fulbright-Hays Summer Seminar. The following items are among the 20 included: Curriculum Project: "'Escritoras Mexicanas Contemporaneas': A Survey of Mexican Women Fiction Writers" (Laura J.…
...) [SDNTK] (Linked To: ISSA EMPRESA UNIPERSONAL; Linked To: INVERSIONES GILFE S.A.; Linked To: INDUITEX LTDA...: INDUITEX LTDA.; Linked To: INVERSIONES GILFE S.A.; Linked To: ORBITAL HORIZONS CORP.; Linked To: FUNDACION... INVESTMENT INC.; Linked To: SBT S.A.; Linked To: ISSA EMPRESA UNIPERSONAL; Linked To: INVERSIONES GILFE S.A...
Swimming cells typically move along a helical path or undergo longitudinal rotation as they swim, arising from chiral asymmetry in hydrodynamic drag or propulsion bending the swimming path into a helix. Helical paths are beneficial for some forms of chemotaxis, but why asymmetric shape is so prevalent when a symmetric shape would also allow highly directional swimming is unclear. Here, I analyse the swimming of the insect life cycle stages of two human parasites; Trypanosoma brucei and Leishmania mexicana. This showed quantitatively how chirality in T. brucei cell shape confers highly directional swimming. High speed videomicrographs showed that T. brucei, L. mexicana and a T. brucei RNAi morphology mutant have a range of shape asymmetries, from wild-type T. brucei (highly chiral) to L. mexicana (near-axial symmetry). The chiral cells underwent longitudinal rotation while swimming, with more rapid longitudinal rotation correlating with swimming path directionality. Simulation indicated hydrodynamic drag on the chiral cell shape caused rotation, and the predicted geometry of the resulting swimming path matched the directionality of the observed swimming paths. This simulation of swimming path geometry showed that highly chiral cell shape is a robust mechanism through which microscale swimmers can achieve highly directional swimming at low Reynolds number. It is insensitive to random variation in shape or propulsion (biological noise). Highly symmetric cell shape can give highly directional swimming but is at risk of giving futile circular swimming paths in the presence of biological noise. This suggests the chiral T. brucei cell shape (associated with the lateral attachment of the flagellum) may be an adaptation associated with the bloodstream-inhabiting lifestyle of this parasite for robust highly directional swimming. It also provides a plausible general explanation for why swimming cells tend to have strong asymmetries in cell shape or propulsion. PMID:28141804
width of the API will n&nQW to 16 meters and thi~ encompasses the entire IU’ea be~ Coast Rd and the·Union Pacific right-of-wa:r boundary as defined in...Salvia mellifera Black sage * * Salvia spathacea Hummingbird sage * Sambucchus mexicana Mexican elderbern· * * Scrophularia atrata 2.3A Black
disease are animals such as desert rats, sloths, horses, rodents, foxes and dogs . 14. SUMrCT TERMS IS. NUMBER OF PAGES Leishmaniasis, sandflies... Ketoconazole and Allopurinol)................................... 311 E. Topical Agents (Paromomycin) ...................... 313 F. Liposomes...panamensis), horses (L. braziliensis), rodents (L. mexicana); and foxes and dogs (L. donovani). In India, inadequately treated visceral infection may
The purpose of this paper is to describe the educational experiences of a Mexican woman in Chicago's Little Village community in the 1980s. The author was born in Mexico and raised in Little Village which has been home to Mexican immigrant communities for decades. Little Village is also home to the largest Mexican-American population in the…
Kathryn L. Purcell; Jared Verner; Lewis W. Oring
We compared laying date, nesting success, clutch size, and productivity of four bird species that nest in boxes and tree cavities to examine whether data from nest boxes are comparable with data from tree cavities. Western Bluebirds (Sialia mexicana) gained the most advantage from nesting in boxes. They initiated egg laying earlier, had higher nesting success, lower...
TITLE: Screening for Inhibitors of Essential Leishmania Glucose Transporters PRINCIPAL INVESTIGATOR: Scott M. Landfear, Ph.D...TITLE AND SUBTITLE Screening for Inhibitors of Essential Leishmania Glucose Transporters 5a. CONTRACT NUMBER 5b. GRANT NUMBER...selective inhibitors of the essential glucose transporters of the parasite Leishmania mexicana. Toward this end, a cell growth assay has been
Smith, Peter H.
One of a series of booklets on world issues, this five-part document presents information about Mexico. Part one examines Mexican history from Cortez to Madero. Emphasis is placed on the revolution era (1910-1920) and the creation of two political parties: the Partido de la Revolucion Mexicana (Mexican Revolutionary Party or PRM) and the Partido…
Serrano-Martín, Xenón; Payares, Gilberto; Mendoza-León, Alexis
Glibenclamide reduced the rate of lesion growth in BALB/c mice infected with Leishmania (Leishmania) mexicana, the effect was dose dependent, and the highest dose proved more effective than glucantime. Cross-resistance to glucantime was found in animals infected with a glibenclamide-resistant line, but combined therapy reduced lesion progression even in the glibenclamide-resistant strain. PMID:17015627
Leishmania Glucose Transporters PRINCIPAL INVESTIGATOR: Scott M. Landfear, Ph.D. CONTRACTING ORGANIZATION: Oregon Health & Science...3. DATES COVERED 1 JUL 2011 - 30 JUN 2012 4. TITLE AND SUBTITLE Screening for Inhibitors of Essential Leishmania Glucose Transporters...function as selective inhibitors of the essential glucose transporters of the parasite Leishmania mexicana. To identify such compounds, a cell growth
Coppola, Federico; Campbell, Juan Iaconis; Herrero, Juan Manuel; Volpe, Emilio; Cersosimo, Tito
Resumen Introducción: Los meningiomas Grado II tienen un comportamiento biológico más agresivo que los Grado I. A partir del año 2007, con los nuevos criterios de clasificación, la incidencia de meningiomas atípicos reportada aumentó hasta un 35%. Objetivo: Establecer diferencias entre los Meningiomas Grado I y II de la clasificación de la OMS, en lo que respecta a: grados de resección de Simpson, localización tumoral, necesidad de reintervención, tratamiento adyuvante, evolución y mortalidad. Métodos: Estudio retrospectivo de 63 pacientes operados entre el periodo 2009-2015. Variables analizadas: sexo, edad, grado histológico, localización, grado de resección quirúrgica, radioterapia adyuvante, mortalidad y evolución. Resultados: Se analizaron 63 pacientes: 51 Grado I y 12 Grado II de la clasificación de la OMS. La distribución por sexo no mostró diferencias entre meningiomas benignos y atípicos. Tampoco el grupo etario de presentación; mediana de 57 años. Un 55% de los meningiomas benignos se localizaron fuera de la base del cráneo versus el 91,6% de los meningiomas atípicos (P = 0.02). En el 74,5% de los meningiomas benignos se logró una resección total (Simpson I-II-III) versus el 58.3% para los atípicos (P = 0.3). Se reintervinieron el 33,3% de meningiomas atípicos en comparación con el 9.8% de los benignos (P = 0.03). Tuvieron una buena evolución el 86,2% de los benignos vs el 53,8% de los GII (P = 0.01). Realizaron radioterapia adyuvante el 33,3% de los meningiomas Grado II vs el 1,9% de los Grado I. Conclusiones: Los meningiomas atípicos cerebrales tienen peor pronóstico evolutivo que los Grado I de la OMS. Presentan una mayor tasa de reintervención y se localizan más frecuentemente fuera de la base del cráneo. La localización pareciera ser un factor de riesgo para el desarrollo de meningiomas atípicos. PMID:29142779
Alayón, Alicia Norma; Rivadeneira, Ana Patricia; Herrera, Carlos; Guzmán, Heidy; Arellano, Dioneris; Echeverri, Isabella
Introducción. La etapa posprandial se asocia con el incremento de marcadores relacionados con el riesgo cardiovascular, cuya intensidad depende del estado metabólico.Objetivo. Determinar el impacto de la ingestión de una comida rica en grasas saturadas sobre el perfil metabólico e inflamatorio y su relación con la obesidad abdominal.Materiales y métodos. Se hizo un ensayo clínico en 42 individuos (21 con obesidad abdominal). Se midieron, en sangre, la glucosa, la insulina, el perfil lipídico, la proteína C reactiva, los lipopolisacáridos y la interleucina 6, en ayunas y después de la ingestión.Resultados. Además de la obesidad, se registró la presencia de resistencia a la insulina y de niveles elevados de triacilglicéridos y proteína C reactiva en ayunas. Asimismo, se detectaron niveles posprandiales más elevados de glucosa, insulina y triacilglicéridos. La interleucina 6 disminuyó en el grupo de personas sin obesidad y los lipopolisacáridos aumentaron en ambos grupos.Conclusión. La ingestión de una comida rica en grasas saturadas produjo un mayor impacto en las variables glucémicas en el grupo con obesidad y, aunque afectó de forma similar los lípidos en ambos grupos, el incremento de triacilglicéridos fue mayor en presencia de una concentración basal elevada y promovió el aumento de lipopolisacáridos. El estado inflamatorio basal y posprandial afectó en mayor medida al grupo con obesidad. El momento posprandial reflejó el estado más frecuente de los individuos en un día normal y permitió evidenciar la capacidad de respuesta metabólica frente a la ingestión de alimentos, así como los estados tempranos de riesgo metabólico.
Aplicadas (INVAP) in support of the development of a satellite by the Argentine national company Empresa Argentina de Soluciones Satelitales (ARSAT).122...reportedly inter- ested in purchasing the state telecommunications firm Empresa Hondureña de Telecomunicaciones (Hondutel), pursuant to plans to...Ministerio de Defensa Na- cional. Ministerio de Relaciones Exteriores , Montevideo, Uru- guay, April 29, 2009. 34. “Simpósio Internacional no Naval Command
Benvenuto, O. G.; Althaus, L. G.; Torres, D. F.
En este trabajo se estudia por primera vez de manera autoconsistente la evolución de las estrellas enanas blancas en el caso de una constante de gravitación G variable en el tiempo. Teniendo en cuenta que: 1) las enanas blancas son en general estrellas muy viejas y 2) su fuente de energía es básicamente de origen térmico y gravitacional, estos objetos son en principio muy adecuados para analizar distintas teorías de gravitación. Los cálculos que aquí presentamos fueron realizados utilizando nuestro código de evolución estelar, el cual calcula la evolución de estrellas enanas blancas por medio del esquema iterativo de Henyey. Dicho código, basado en una descripción física muy detallada, ha sido modificado para tener en cuenta la variación del valor de G. Encontramos que un G variable (decreciente en el tiempo) modifica fuertemente la evolución de las enanas blancas, conduciendo a un rápido enfriamiento de la estrella. Nuestros resultados son comparados con recientes datos observacionales sobre la función de luminosidad de las enanas blancas.
Arteaga, María Clara; Moreno-Letelier, Alejandra; Mastretta-Yanes, Alicia; Vázquez-Lobo, Alejandra; Breña-Ochoa, Alejandra; Moreno-Estrada, Andrés; Eguiarte, Luis E.; Piñero, Daniel
The present dataset comprises 36,931 SNPs genotyped in 46 maize landraces native to Mexico as well as the teosinte subspecies Zea maiz ssp. parviglumis and ssp. mexicana. These landraces were collected directly from farmers mostly between 2006 and 2010. We accompany these data with a short description of the variation within each landrace, as well as maps, principal component analyses and neighbor joining trees showing the distribution of the genetic diversity relative to landrace, geographical features and maize biogeography. High levels of genetic variation were detected for the maize landraces (HE = 0.234 to 0.318 (mean 0.311), while slightly lower levels were detected in Zea m. mexicana and Zea m. parviglumis (HE = 0.262 and 0.234, respectively). The distribution of genetic variation was better explained by environmental variables given by the interaction of altitude and latitude than by landrace identity. This dataset is a follow up product of the Global Native Maize Project, an initiative to update the data on Mexican maize landraces and their wild relatives, and to generate information that is necessary for implementing the Mexican Biosafety Law. PMID:26981357
Vega, Francisco J.; Ahyong, Shane T.; Espinosa, Belinda; Flores-Ventura, José; Luna, Laura; González-González, Arturo H.
A new genus and species of the Mathildellidae Prebranchioplax cretacica (Crustacea: Decapoda: Goneplacoidea) is reported from shallow marine sediments of the upper Campanian Parras Shale and Cerro del Pueblo Formation (Parras Basin), Coahuila, NE Mexico. Prebranchioplax cretacica was collected from siliceous concretions associated with more abundant specimens of the retroplumid Costacopluma mexicana Vega and Perrilliat, 1989. P. cretacica bears similarities to Eocene species of Branchioplax from Japan, USA (Alaska and Washington), England, Hungary and Tajikistan as well as with Eogeryonidae (Portunoidea) species from the Upper Cretaceous of Spain and Marocarcinidae (Styracocarcinus) from Morocco. However, clear differences in the carapace frontal shape places P. cretacica in the Mathildellidae. This record represents the oldest known Mathildellidae, and along with the Retroplumidae, appear to have originated during the Late Cretaceous in ancient seas of Mexico, with a wide distribution during Paleogene times becoming restricted today to deep waters of the Indo-Pacific region and Atlantic Ocean. Comments on preservation and morphology of Costacopluma mexicana are also included. Crab specimens preserved in siliceous concretions from one locality (Entronque) show peculiar desiccation marks, and a possible model of taphonomy.
Ogungbe, Ifedayo Victor; Setzer, William N
Neglected Tropical Diseases (NTDs), like leishmaniasis, are major causes of mortality in resource-limited countries. The mortality associated with these diseases is largely due to fragile healthcare systems, lack of access to medicines, and resistance by the parasites to the few available drugs. Many antiparasitic plant-derived isoprenoids have been reported, and many of them have good in vitro activity against various forms of Leishmania spp. In this work, potential Leishmania biochemical targets of antiparasitic isoprenoids were studied in silico. Antiparasitic monoterpenoids selectively docked to L. infantum nicotinamidase, L. major uridine diphosphate-glucose pyrophosphorylase and methionyl t-RNA synthetase. The two protein targets selectively targeted by germacranolide sesquiterpenoids were L. major methionyl t-RNA synthetase and dihydroorotate dehydrogenase. Diterpenoids generally favored docking to L. mexicana glycerol-3-phosphate dehydrogenase. Limonoids also showed some selectivity for L. mexicana glycerol-3-phosphate dehydrogenase and L. major dihydroorotate dehydrogenase while withanolides docked more selectively with L. major uridine diphosphate-glucose pyrophosphorylase. The selectivity of the different classes of antiparasitic compounds for the protein targets considered in this work can be explored in fragment- and/or structure-based drug design towards the development of leads for new antileishmanial drugs.
Arteaga, María Clara; Moreno-Letelier, Alejandra; Mastretta-Yanes, Alicia; Vázquez-Lobo, Alejandra; Breña-Ochoa, Alejandra; Moreno-Estrada, Andrés; Eguiarte, Luis E; Piñero, Daniel
The present dataset comprises 36,931 SNPs genotyped in 46 maize landraces native to Mexico as well as the teosinte subspecies Zea maiz ssp. parviglumis and ssp. mexicana. These landraces were collected directly from farmers mostly between 2006 and 2010. We accompany these data with a short description of the variation within each landrace, as well as maps, principal component analyses and neighbor joining trees showing the distribution of the genetic diversity relative to landrace, geographical features and maize biogeography. High levels of genetic variation were detected for the maize landraces (H E = 0.234 to 0.318 (mean 0.311), while slightly lower levels were detected in Zea m. mexicana and Zea m. parviglumis (H E = 0.262 and 0.234, respectively). The distribution of genetic variation was better explained by environmental variables given by the interaction of altitude and latitude than by landrace identity. This dataset is a follow up product of the Global Native Maize Project, an initiative to update the data on Mexican maize landraces and their wild relatives, and to generate information that is necessary for implementing the Mexican Biosafety Law.
the problem of elite cohesion, including the mechanisms-- especially the camarilla system--whereby balance and equilibrium, control and cooptation...Generacicnes: Los Protagonistas de Ia Reforma y la Revoluci(n Mexicana, Secretaria de Educacion Pblica, Consejo Nacional de Fomento Educat ivo, Mexico City...loyalty and discipline toward the system as a whole, and especially its apex, the president, and its key institution, the PRI. All this looks different
plants such as Azolla mexicana (mosquito fern), Lemna minor (common duckweed), and Spirodela polyrhiza (great duckweed). Many rotting logs float in the...woods. Lemna minor L. COMMON DUCKWEED. Abundant on quiet water in old sloughs and oxbows. *Lepidium virginicum L. COMMON PEPPERGRASS. Abundant but...Occasional in bottomland forests; uncommon in old fields. Strix varia Barton. BARRED OWL. R. Heard once in a bottomland forest. Chordeiles minor
Bilbao-Ramos, Pablo; Dea-Ayuela, M Auxiliadora; Cardenas-Alegría, Oscar; Salamanca, Efraín; Santalla-Vargas, José Antonio; Benito, Cesar; Flores, Ninoska; Bolás-Fernández, Francisco
The Plurinational State of Bolivia is one of the Latin American countries with the highest prevalence of leishmaniasis, highlighting the lowlands of the Department of La Paz where about 50% of the total cases were reported. The control of the disease can be seriously compromised by the intrinsic variability of the circulating species that may limit the efficacy of treatment while favoring the emergence of resistance. Fifty-five isolates of Leishmania from cutaneous and mucocutaneous lesions from patients living in different provinces of the Department of La Paz were tested. Molecular characterization of isolates was carried out by 3 classical markers: the rRNA internal transcribed spacer 1 (ITS-1), the heat shock protein 70 (HSP70) and the mitochondrial cytochrome b (Cyt-b). These markers were amplified by PCR and their products digested by the restriction endonuclease enzymes AseI and HaeIII followed by subsequent sequencing of Cyt-b gene and ITS-1 region for subsequent phylogenetic analysis. The combined use of these 3 markers allowed us to assign 36 isolates (65.5%) to the complex Leishmania (Viannia) braziliensis, 4 isolates (7, 27%) to L. (Viannia) lainsoni. and the remaining 15 isolates (23.7%) to a local variant of L. (Leishmania) mexicana. Concerning in vitro drug susceptibility the amastigotes from all isolates where highly sensitive to Fungizone ® (mean IC 50 between 0.23 and 0.5μg/mL) whereas against Glucantime ® the sensitivity was moderate (mean IC 50 ranging from 50.84μg/mL for L. (V.) braziliensis to 18.23μg/mL for L. (L.) mexicana. L. (V.) lainsoni was not sensitive to Glucantime ® . The susceptibility to miltefosine was highly variable among species isolates, being L. (L.) mexicana the most sensitive, followed by L. (V.) braziliensis and L. (V.) lainsoni (mean IC 50 of 8.24μg/mL, 17.85μg/mL and 23.28μg/mL, respectively). Copyright © 2017. Published by Elsevier B.V.
Alzahrani, Khalid J H; Ali, Juma A M; Eze, Anthonius A; Looi, Wan Limm; Tagoe, Daniel N A; Creek, Darren J; Barrett, Michael P; de Koning, Harry P
Leishmania pyrimidine salvage is replete with opportunities for therapeutic intervention with enzyme inhibitors or antimetabolites. Their uptake into cells depends upon specific transporters; therefore it is essential to establish whether various Leishmania species possess similar pyrimidine transporters capable of drug uptake. Here, we report a comprehensive characterization of pyrimidine transport in L. major and L. mexicana. In both species, two transporters for uridine/adenosine were detected, one of which also transported uracil and the antimetabolites 5-fluoruracil (5-FU) and 5F,2'deoxyuridine (5F,2'dUrd), and was designated uridine-uracil transporter 1 (UUT1); the other transporter mediated uptake of adenosine, uridine, 5F,2'dUrd and thymidine and was designated Nucleoside Transporter 1 (NT1). To verify the reported L. donovani model of two NT1-like genes encoding uridine/adenosine transporters, and an NT2 gene encoding an inosine transporter, we cloned the corresponding L. major and L. mexicana genes, expressing each in T. brucei. Consistent with the L. donovani reports, the NT1-like genes of either species mediated the adenosine-sensitive uptake of [ 3 H]-uridine but not of [ 3 H]-inosine. Conversely, the NT2-like genes mediated uptake of [ 3 H]-inosine but not [ 3 H]-uridine. Among pyrimidine antimetabolites tested, 5-FU and 5F,2'dUrd were the most effective antileishmanials; resistance to both analogs was induced in L. major and L. mexicana. In each case it was found that the resistant cells had lost the transport capacity for the inducing drug. Metabolomics analysis found that the mechanism of action of 5-FU and 5F-2'dUrd was similar in both Leishmania species, with major changes in deoxynucleotide metabolism. We conclude that the pyrimidine salvage system is highly conserved in Leishmania species - essential information for the development of pyrimidine-based chemotherapy. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights
Valero Gaspar, Teresa; Del Pozo de la Calle, Susana; Ruiz Moreno, Emma; Ávila Torres, Osé Manuel; Varela-Moreiras, Gregorio; Cuadrado Vives, Carmen
Introducción: a finales del siglo xx, no se conocía con precisión si la comida del comedor escolar contribuía adecuadamente a la dieta de la población infantil. Además, este servicio complementario no se contemplaba en el proyecto educativo del centro pese a considerarse fundamental en todas sus dimensiones.Objetivo: describir el origen y desarrollo del programa de comedores escolares de la Comunidad de Madrid (CM) en 15 años desde su implantación.Métodos: se elaboró una normativa a cumplir por las empresas de restauración, y que contemplaba aspectos nutricionales y de composición y variedad de los menús, que se utilizó en los concursos para acceder a la prestación del servicio de comedor escolar, publicados en los años 2001, 2002, 2005, 2009 y 2013. Además se realizaron visitas acreditadas a los centros sin previo aviso para verifi car el cumplimiento de la documentación aportada durante el concurso.Resultados: los criterios más actuales sobre programación y elaboración de menús escolares se recogen en el Pliego de Prescripciones Técnicas del año 2013 (C-504/001-2013). Un 92% de las empresas de restauración superaron los cinco concursos habidos en los 15 años de funcionamiento. Hasta el año 2014, se han realizado 755 visitas, revisándose un total de 574 centros.Conclusiones: el programa de comedores escolares de la CM, desde su implementación pionera en España, ha contribuido a la mejora del servicio complementario de comedor. En estos años se han ido incluyendo nuevos requisitos dietéticos y nutricionales que han logrado menús cada vez más ajustados a las recomendaciones de la población escolar.
Galindo, Rene; Medina, Christina
Parental agency is examined in the creation of a dance performance by a group of Mexican immigrant mothers that combined a mixture of genres into an educational message. The "folklorico" performance resulted from a process of cultural appropriation involving linguistic, cultural, and experiential "translations." This process was concerned with…
Lewin, Ralph A.
A new species of Chlamydomonas, namely, C. sajao nov. sp. of the Volvocales, Chlorophyta was isolated from a duckweed growing near a ricefield in the vicinity of Guangzhou, China. This interesting unicellular green alga, similar to C. mexicana from Mexico, secretes quantities of extracellular mucilaginous polysaccharides, and may be employed in improving soil quality. The new species resembles C. waldenburgensis Moewus in most characteristics but differs in three important features.
incriminated as vectors of Leishmania mexicana among rodents and/or humans from Mexico to the Amazon Basin. Specimens referable to L. olmeca olmeca...in the format similar to that given for the species group baityi included in this report. Additional phlebotomines from Tanzania, Brazil, Peru and...species group baityi included in this report. Additional phlebotomines from Tanzania, Brazil, Peru and Venezuela were slide-mounted and added to the
on the Internet. 4From a statement by Subcommandante Marcos, March 4, 1994, as reported by the Academia Mexicana de Derechos Humanos , Special...Indigenas de Mexico, Mexico City: Comisiön Nacional de Derechos Humanos , 1995. Evan, William M., "An Organization-Set Model of Interorganizational...City: Comision Nacional de Dere- chos Humanos , 1995. Meisel, James, The Fall of the Republic: Military Revolt in France, Ann Arbor: University of
Research in Biological and Medical Sciences, Including Biochemistry, Communicable Disease and Immunology, Internal Medicine, Nuclear Medicine, Physiology, Psychiatry, Surgery, and Veterinary Medicine. Volume 1
Preparation of immunoglobulins for lodonation. Goat anti-rabbit gamma globulin (GARG) was obtained from Nutritional Biochemlcals as the 7S fraction of the...upon the parasite of the Yucatan peninsula - British Honduras area, primarily upon the basis of its apparent failure to ever cause mucocutaneous...to Texas is Yucatan , where only L. mexicana is known to occur. With no intent to imply an argument for subspecies status, this isolate will
Real, Fernando; Vidal, Ramon Oliveira; Carazzolle, Marcelo Falsarella; Mondego, Jorge Maurício Costa; Costa, Gustavo Gilson Lacerda; Herai, Roberto Hirochi; Würtele, Martin; de Carvalho, Lucas Miguel; Carmona e Ferreira, Renata; Mortara, Renato Arruda; Barbiéri, Clara Lucia; Mieczkowski, Piotr; da Silveira, José Franco; Briones, Marcelo Ribeiro da Silva; Pereira, Gonçalo Amarante Guimarães; Bahia, Diana
We present the sequencing and annotation of the Leishmania (Leishmania) amazonensis genome, an etiological agent of human cutaneous leishmaniasis in the Amazon region of Brazil. L. (L.) amazonensis shares features with Leishmania (L.) mexicana but also exhibits unique characteristics regarding geographical distribution and clinical manifestations of cutaneous lesions (e.g. borderline disseminated cutaneous leishmaniasis). Predicted genes were scored for orthologous gene families and conserved domains in comparison with other human pathogenic Leishmania spp. Carboxypeptidase, aminotransferase, and 3'-nucleotidase genes and ATPase, thioredoxin, and chaperone-related domains were represented more abundantly in L. (L.) amazonensis and L. (L.) mexicana species. Phylogenetic analysis revealed that these two species share groups of amastin surface proteins unique to the genus that could be related to specific features of disease outcomes and host cell interactions. Additionally, we describe a hypothetical hybrid interactome of potentially secreted L. (L.) amazonensis proteins and host proteins under the assumption that parasite factors mimic their mammalian counterparts. The model predicts an interaction between an L. (L.) amazonensis heat-shock protein and mammalian Toll-like receptor 9, which is implicated in important immune responses such as cytokine and nitric oxide production. The analysis presented here represents valuable information for future studies of leishmaniasis pathogenicity and treatment.
Real, Fernando; Vidal, Ramon Oliveira; Carazzolle, Marcelo Falsarella; Mondego, Jorge Maurício Costa; Costa, Gustavo Gilson Lacerda; Herai, Roberto Hirochi; Würtele, Martin; de Carvalho, Lucas Miguel; e Ferreira, Renata Carmona; Mortara, Renato Arruda; Barbiéri, Clara Lucia; Mieczkowski, Piotr; da Silveira, José Franco; Briones, Marcelo Ribeiro da Silva; Pereira, Gonçalo Amarante Guimarães; Bahia, Diana
We present the sequencing and annotation of the Leishmania (Leishmania) amazonensis genome, an etiological agent of human cutaneous leishmaniasis in the Amazon region of Brazil. L. (L.) amazonensis shares features with Leishmania (L.) mexicana but also exhibits unique characteristics regarding geographical distribution and clinical manifestations of cutaneous lesions (e.g. borderline disseminated cutaneous leishmaniasis). Predicted genes were scored for orthologous gene families and conserved domains in comparison with other human pathogenic Leishmania spp. Carboxypeptidase, aminotransferase, and 3′-nucleotidase genes and ATPase, thioredoxin, and chaperone-related domains were represented more abundantly in L. (L.) amazonensis and L. (L.) mexicana species. Phylogenetic analysis revealed that these two species share groups of amastin surface proteins unique to the genus that could be related to specific features of disease outcomes and host cell interactions. Additionally, we describe a hypothetical hybrid interactome of potentially secreted L. (L.) amazonensis proteins and host proteins under the assumption that parasite factors mimic their mammalian counterparts. The model predicts an interaction between an L. (L.) amazonensis heat-shock protein and mammalian Toll-like receptor 9, which is implicated in important immune responses such as cytokine and nitric oxide production. The analysis presented here represents valuable information for future studies of leishmaniasis pathogenicity and treatment. PMID:23857904
Flegontov, Pavel; Butenko, Anzhelika; Firsov, Sergei; Kraeva, Natalya; Eliáš, Marek; Field, Mark C.; Filatov, Dmitry; Flegontova, Olga; Gerasimov, Evgeny S.; Hlaváčová, Jana; Ishemgulova, Aygul; Jackson, Andrew P.; Kelly, Steve; Kostygov, Alexei Y.; Logacheva, Maria D.; Maslov, Dmitri A.; Opperdoes, Fred R.; O’Reilly, Amanda; Sádlová, Jovana; Ševčíková, Tereza; Venkatesh, Divya; Vlček, Čestmír; Volf, Petr; Jan Votýpka; Záhonová, Kristína; Yurchenko, Vyacheslav; Lukeš, Julius
Many high-quality genomes are available for dixenous (two hosts) trypanosomatid species of the genera Trypanosoma, Leishmania, and Phytomonas, but only fragmentary information is available for monoxenous (single-host) trypanosomatids. In trypanosomatids, monoxeny is ancestral to dixeny, thus it is anticipated that the genome sequences of the key monoxenous parasites will be instrumental for both understanding the origin of parasitism and the evolution of dixeny. Here, we present a high-quality genome for Leptomonas pyrrhocoris, which is closely related to the dixenous genus Leishmania. The L. pyrrhocoris genome (30.4 Mbp in 60 scaffolds) encodes 10,148 genes. Using the L. pyrrhocoris genome, we pinpointed genes gained in Leishmania. Among those genes, 20 genes with unknown function had expression patterns in the Leishmania mexicana life cycle suggesting their involvement in virulence. By combining differential expression data for L. mexicana, L. major and Leptomonas seymouri, we have identified several additional proteins potentially involved in virulence, including SpoU methylase and U3 small nucleolar ribonucleoprotein IMP3. The population genetics of L. pyrrhocoris was also addressed by sequencing thirteen strains of different geographic origin, allowing the identification of 1,318 genes under positive selection. This set of genes was significantly enriched in components of the cytoskeleton and the flagellum. PMID:27021793
Riesch, Rüdiger; Plath, Martin; García de León, Francisco J.; Schlupp, Ingo
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.
Peraza-Sánchez, S R; Cen-Pacheco, F; Noh-Chimal, A; May-Pat, F; Simá-Polanco, P; Dumonteil, E; García-Miss, M R; Mut-Martín, M
Methanol extracts were prepared from different parts of 18 plants collected in the Yucatan peninsula and evaluated in an in vitro bioassay for leishmanicidal activity against Leishmania mexicana promastigotes. The ten most potent plant extracts (IC(50)<50 microg/ml) were Aphelandra scabra leaves, Byrsonima bucidaefolia bark, Byrsonima crassifolia bark, Clusia flava leaves, Cupania dentata bark, Diphysa carthagenensis leaves, Dorstenia contrajerva whole plant, Milleria quinqueflora roots, Tridax procumbens whole plant, and Vitex gaumeri bark.
Liberal (Liberal Party) PRI Partido Revolucionario Institucional SCT Secretaría de Comunicaciones y Transportes MEXTELCO Telefónica Mexicana TELMEX...Skopec, eds. (Oxford: Oxford University Press, 1998), 168. 14 Carlos A. Merchan Escalante, Historia de las Comunicaciones y los Transportes en México...México, D.F., Secretaría de Comunicaciones y Transportes, 1988, 144. 20 Western Electric Telephone Company, later becoming Compañía Telefónica y
Trans- Pecos rat snake, gray-banded kingsnake (Texas), big-bend milk snake (Texas), and Texas lyre snake should be looked for. The rock rattlesnake...should be . looked for primarily in the Hueco Mountains on Fort Bliss. Gray-banded kingsnake , Lampropeltis mexicana alterna - T This snake occurs in...rocky outcrops and cliffs. The big-bend milk snake, Trans-Pecos rat snake, Texas lyre snake, and gray-banded kingsnake should all be expected to occur
Orozco-Davila, D.; Hernandez, R.; Meza, S.
origins. (author) [Spanish] La colonia actualmente usada para controlar la mosca mexicana de la fruta, Anastrepha ludens (Loew), en Mexico tiene mas de 10 anos en cria masiva. Los insectos esteriles son liberados en una gran variedad de condiciones ambientales como parte de un control integrado para suprimir diversas poblaciones de esta plaga dentro de la Republica Mexicana. El objetivo de este documento esta dirigido a revisar el desempeno de las moscas esteriles frente a poblaciones silvestres procedentes de diferentes ambientes y para esto se realizaron comparaciones de compatibilidad y competitividad sexual de las moscas esteriles contra poblaciones silvestres de seis estados representativos de la Republica Mexicana: Nuevo Leon, Tamaulipas, Sinaloa, Nayarit, Michoacan y Chiapas. Los resultados obtenidos manifiestan diferencias en el horario de inicio de llamado y mayor actividad sexual del macho entre las moscas provenientes de cada estado. Sin embargo el indice de aislamiento (ISI) reflejo compatibilidad sexual entre la cepa de laboratorio y todas las poblaciones analizadas, indicando que los individuos esteriles pueden aparearse satisfactoriamente con las poblaciones silvestres de los seis estados. El indice de efectividad de apareamiento del macho (MRPI) reflejo de manera global que los machos esteriles son tan efectivos para copular como los silvestres. El indice de efectividad de apareamiento de la hembra (FRPI) reflejo que en la mayoria de los estados las hembras silvestres copularon en mayor proporcion que las hembras esteriles, excepto para las poblaciones de Tamaulipas y Chiapas. En general, la baja participacion de las hembras esteriles en el campo permitio al macho esteril ampliar su probabilidad de apareamiento con las hembras silvestres. En cuanto al indice de esterilidad relativa (RSI), observamos que la aceptacion de las hembras silvestres al macho esteril (25-55%) fue similar a la de los machos silvestres. Las hembras de la poblacion de Chiapas
Eichler, P.P.B.; Eichler, B.B.; De Miranda, L. B.; Rodrigues, A.R.
Numerical analyses of modern foraminiferal abundance and environmental data from the Bertioga Channel (Sa??o Paulo, Brazil) reveal multiple biofacies within an overall paralic setting. Despite its fisheries, mariculture and attraction to tourists, the environmental state of Bertioga Channel remains poorly studied. The present investigation is an attempt to partly fill this gap; the parameters examined include depth, salinity, temperature, organic carbon, sulfur content and bottom sediment type. Muddy sediments with high organic carbon content derived from land drainage are found in the inner parts of the channel, whereas sandy sediment dominates the areas adjacent to the Atlantic Ocean. In the eastern entrance to the channel, sandy sediment contain species of Rotaliida from Facies 1 (including Elphidium discoidale, Elphidium poeyanum, Hanzawaia boueana, Pararotalia cananeiaensis and Nonionella atlantica), reflecting normal marine salinity. Sediments with high percentages of silt and clay in polyhaline and eurybaline environments of the eastern part and Itapanhau?? River contain Facies 2, which includes Ammonia beccarii and Pararotalia cananeiaensis. In the western entrance and central, western and eastern parts, where salinities vary from 18 to 30 psu and the sediments contain both low and high organic carbon, the foraminifera from Facies 3 are dominated by Quinqueloculina milletti, Arenoparrella mexicana, Pararotalia cananeiaensis, Ammonia beccarii, Buliminella elegantissima, Elphidium sp., Elphidium excavatum, Elphidium gunteri and Elphidium poeyanum. In mesohaline and polyhaline waters of the central part, the organic-carbon-rich silt and clay contain Facies 4, which includes Ammonia beccarii, Pararotalia cananeiaensis, Elphidium excavatum and Elphidium sp. Most of organic-carbon-enriched, silty-clay substrates that are subject to the highest fresh-water discharge and high bottom temperatures support two different assemblages: one of mostly Rotaliina and the
returned legal status to the faction led by Guillermo Estevez Boero which had appealed Judge Marquardt’s decision. Another faction led by Victor...borrowing more money." Jamaica’s foreign debt at the end of last year stood at 2.4 billion dollars ( J ) • During 1982 the country had a negative trade...stands and retail grocery stores, a kilogram of eggs reaches a price of 100 pesos. In the self service stores Comercial Mexicana, Blanco , Aurrera
Speaker - Legal Advocates Seminar: "Motor Vehicle Crash Analysis."Sheraton Bal Harbor. Miami Beach, FL. January 30t. 1997 SICU Infections Course...Surgical Intensive Care Data Managem3nt System." London, England. June 2nd. 1981 VII Reuni6n Nacional de Medicina CrItica y Terapia Intensiva...Asociaci6n Mexicana de Medicine Critica y Terapia Intensive. Curso de Actualizaci6n Profesional en Medicina CrItica: "Development of Intensive Care Systems
Finer, Neal B.
Designed to be used as part of a comprehensive social studies program on Mexican culture, this two-volume manual, written in Spanish, offers an instructional package on Mexican culture, stressing an art-architecture perspective, which can be used at the secondary, college and adult levels. The teacher's guide, Volume I, includes a discussion of a…
Woodman, N.; Morgan, J.P.J.
Variation in the forefoot skeleton of small-eared shrews (family Soricidae, genus Cryptotis) has been previously documented, but the paucity of available skeletons for most taxa makes assessment of the degrees of intraspecific and interspecific variation difficult. We used a digital X-ray system to extract images of the forefoot skeleton from 101 dried skins of eight taxa (seven species, including two subspecies of one species) of these shrews. Lengths and widths of each of the four bones of digit III were measured directly from the digital images, and we used these data to quantify variation within and among taxa. Analysis of the images and measurements showed that interspecific variation exceeds intraspecific variation. In fact, most taxa could be distinguished in multivariate and some bivariate plots. Our quantitative data helped us define a number of specific forefoot characters that we subsequently used to hypothesize evolutionary relationships among the taxa using the exhaustive search option in PAUP, a computer program for phylogenetic analysis. The resulting trees generally concur with previously published evolutionary hypotheses for small-eared shrews. Cryptotis meridensis, a taxon not previously examined in recent phylogenies, is rooted at the base of the branch leading to the C. mexicana group of species. The position of this species suggests that the mostly South American C. thomasi group shares an early ancestor with the C. mexicana group.
Sood, A; Prasanna, R; Prasanna, B M; Singh, P K
The cyanobionts isolated from 10 Azolla accessions belonging to 6 species (Azolla mexicana, A. microphylla, A. rubra, A. caroliniana, A. filiculoides, A. pinnata) were cultured under laboratory conditions and analyzed on the basis of whole cell protein profiles and molecular marker dataset generated using repeat sequence primers (STRR(mod) and HipTG). The biochemical and molecular marker profiles of the cyanobionts were compared with those of the free-living cyanobacteria and symbiotic Nostoc strains from Anthoceros sp., Cycas sp. and Gunnera monoika. Cluster analysis revealed the genetic diversity among the selected strains, and identified 3 distinct clusters. Group 1 included cyanobionts from all the 10 accessions of Azolla, group 2 comprised all the symbiotic Nostoc strains, while group 3 included the free-living cyanobacteria belonging to the genera Nostoc and Anabaena. The interrelationships among the Azolla cyanobionts were further revealed by principal component analysis. Cyanobionts from A. caroliniana-A. microphylla grouped together while cyanobionts associated with A. mexicana-A. filiculoides along with A. pinnata formed another group. A. rubra cyanobionts had intermediate relationship with both the subgroups. This is the first study analyzing the diversity existing among the cultured cyanobionts of diverse Azolla species through the use of biochemical and molecular profiles and also the genetic distinctness of these free-living cyanobionts as compared to cyanobacterial strains of the genera Anabaena and Nostoc.
Tobler, M; Plath, M; Riesch, R; Schlupp, I; Grasse, A; Munimanda, G K; Setzer, C; Penn, D J; Moodley, Y
The unprecedented polymorphism in the major histocompatibility complex (MHC) genes is thought to be maintained by balancing selection from parasites. However, do parasites also drive divergence at MHC loci between host populations, or do the effects of balancing selection maintain similarities among populations? We examined MHC variation in populations of the livebearing fish Poecilia mexicana and characterized their parasite communities. Poecilia mexicana populations in the Cueva del Azufre system are locally adapted to darkness and the presence of toxic hydrogen sulphide, representing highly divergent ecotypes or incipient species. Parasite communities differed significantly across populations, and populations with higher parasite loads had higher levels of diversity at class II MHC genes. However, despite different parasite communities, marked divergence in adaptive traits and in neutral genetic markers, we found MHC alleles to be remarkably similar among host populations. Our findings indicate that balancing selection from parasites maintains immunogenetic diversity of hosts, but this process does not promote MHC divergence in this system. On the contrary, we suggest that balancing selection on immunogenetic loci may outweigh divergent selection causing divergence, thereby hindering host divergence and speciation. Our findings support the hypothesis that balancing selection maintains MHC similarities among lineages during and after speciation (trans-species evolution). © 2014 The Authors. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.
Calderón, Angela I; Romero, Luz I; Ortega-Barría, Eduardo; Solís, Pablo N; Zacchino, Susana; Gimenez, Alberto; Pinzón, Roberto; Cáceres, Armando; Tamayo, Giselle; Guerra, Carlos; Espinosa, Alex; Correa, Mireya; Gupta, Mahabir P
In order to explore rationally the medical potential of the plant biodiversity of the Central and South American region as a source of novel antiparasitic molecules, a multinational Organization of American States (OAS) project, which included the participation of multidisciplinary research centers from Argentina, Bolivia, Colombia, Costa Rica, Guatemala, Nicaragua and Panama, was carried out during the period 2001-2004. This project aimed at screening organic plant extracts for antitrypanosomal, antileishmanial and antimalarial activities and subsequently isolating and characterizing bioactive molecules. Plants for antiparasitic screening were selected from a database of ethnomedical uses of Latin American plants (PlanMedia) based on the amount of biological and chemical information available in the literature. We report here the evaluation of 452 extracts from 311 plant species in vitro screens against Plasmodium falciparum, Leishmania mexicana, and Trypanosoma cruzi. Out of 311 species tested, 17 plants (5.4%) showed antiparasitic activities at IC(50) values < or = 10 microg/mL. The most active plants were Acnistus arborescens (L.) Schltdl. (Solanaceae) (leaf, EtOH, IC(50): 4 microg/mL) Monochaetum myrtoideum Naudin (Melastomataceae) (leaf, MeOH, IC(50): 5 microg/mL) and Bourreria huanita (Lex.) Hemsl. (Boraginaceae) (branch, EtOH, IC(50): 6 microg/mL). These were selectively active against P. falciparum, L. mexicana and T. cruzi, respectively.
to the negotiated transition: The case of Mexico in comparative perspective],” Revista Mexicana de Ciencias Politicas y Sociales 40, no. 162 (December...2012 [Mexican ports in the XXI century: Situation and debate 1991–2012],” Ciencia y Mar 15, no. 45 (2011): 25, 19–62 99 According to Wikipedia, a...2012 [Mexican ports in the XXI century: Situation and debate 1991– 2012].” Ciencia y Mar 15, no. 45 (2011): 19–62. Oyarvide, Cesar Morales. “La Guerra
Yamamoto-Furusho, J K; Bosques-Padilla, F; Daffra, P; De Paula, J A; Etchevers, J; Galiano, M T; Ibañez, P; Juliao, F; Kotze, P G; Marroquín de la Garza, J M; Monreal Robles, R; Rocha, J L; Steinwurz, F; Vázquez-Frías, R; Veitia, G; Zaltman, C
This is the first Latin American Consensus of the Pan American Crohn's and Colitis Organisation (PANCCO) regarding special situations in patients with inflammatory bowel disease (IBD). The aim of this consensus is to raise awareness in the medical community in all Latin American countries with respect to pregnancy, vaccinations, infections, neoplasms, including colorectal cancer, and pediatric issues in patients with IBD. Copyright © 2017 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.
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
Galileo, Maria Helena M; Martins, Ubirajara R; Santos-Silva, Antonio
Six new species and one new genus are described: Criodion spinosum sp. nov. (Cerambycini), from Bolivia; Eburodacrys wappesi sp. nov. and Eburodacrys skillmani sp. nov. (Eburiini), from Bolivia; Eupempelus rileyorum sp. nov. (Heteropsini) from Panama; Sphalloeme mexicana sp. nov. (Oemini), from Mexico; Wappesoeme camiri sp. nov., new genus (Oemini), from Bolivia. Wappesoeme, Eburodacrys wappesi, E. skillmani, Eupempelus rileyorum, and Criodion spinosum are included in previously published keys. Anelaphus erakyra nomen novum for A. maculatus Galileo et al., 2014 is established.
Alvarez-Nodarse, R.; Atakishiyeva, M. K.; Atakishiyev, N. M.
We discuss a q-analogue of the linear harmonic oscillator in quantum mechanics based on a q-extension of the classical Hermite polynomials H n ( x) recently introduced by us in R. Alvarez-Nodarse et al.: Boletin de la Sociedad Matematica Mexicana (3) 8 (2002) 127. The wave functions in this q-model of the quantum harmonic oscillator possess the continuous orthogonality property on the whole real line ℝ with respect to a positive weight function. A detailed description of the corresponding q-system is carried out.
Guiroy, Alfredo; Gagliardi, Martín; Sícoli, Alfredo; Masanés, Nicolás Gonzalez; Ciancio, Alejandro Morales; Jalón, Pablo; Mezzadri, Juan José
Resumen Introducción: Analizar y describir los parámetros sagitales espinales y pelvianos de una serie de 100 voluntarios argentinos. Métodos: Se realizaron prospectivamente espinogramas digitalizados de perfil a 100 voluntarios (30 hombres y 70 mujeres), con un promedio de edad 34,14 años. Todos los voluntarios eran asintomáticos al momento de realizarse el estudio. Los espinogramas se hicieron en un equipo Kodak Elite CR. Se realizaron las mediciones usando el software Surgimap®, versión 220.127.116.11.2. Se tomaron los siguientes parámetros: C7 SVA, C2-C7 CL, TK, LL, TPA, T1 tilt, PI, PT, SS, ángulo L4-S1, ángulo L1-L4, PI-LL y CTPA. Los datos fueron analizados empleando el paquete estadístico Medcalc 11.2. Se determinaron las estadísticas descriptivas adecuadas para cada variable según su escala de medición y distribución. Se realizó la estimación de intervalos de referencia del 95% y de intervalos de confianza del 95% para todas las variables. Así, el nivel de significación obtenido fue igual a 0.05. Se dividió a los voluntarios según la clasificación morfométrica de Roussouly en cuatro tipos. Resultados: El promedio para cada variable fue CL −10.04, TK 30.14, T1SPi −6.5, L1-L4 −12.45, L4-S1 −46.16, CTPA 2.5, TPA 4.65, PT 11.22, PI 48.04, LL −59.10, PI-LL −11.11, C7 SVA mm −23.68. Los ±2 desvíos estándar para cada variable fueron: CL (−33.26, 13.12); TK (17.15, 43.30); T1SPi (−11.78, −1.25), L1-L4 (−25.55, 0.25), L4-S1 (−64.44, −27.55), CTPA (0.33, 4.80), TPA (−8.64, 18.22), PT (−1.99, 24.75), PI (25.23, 71.44), LL (−78.74, −39.89), PI-LL (−29.10, 7.04), C7 SVA mm (−79.45, 32.08). Conclusión: En esta serie prospectiva de 100 adultos voluntarios se determinaron los valores de normalidad de los parámetros sagitales espinales y pelvianos en una población de Argentina. PMID:29430329
Gonzales, Gustavo F.; Zevallos, Alisson; Gonzales-Castañeda, Cynthia; Nuñez, Denisse; Gastañaga, Carmen; Cabezas, César; Naeher, Luke; Levy, Karen; Steenland, Kyle
RESUMEN El presente artículo es una revisión sobre la contaminación del agua, el aire y el efecto del cambio climático en la salud de la población peruana. Uno de los principales contaminantes del aire es el material particulado menor de 2,5 μ (PM 2,5), en la ciudad de Lima, anualmente 2300 muertes prematuras son atribuibles a este contaminante. Otro problema es la contaminación del aire domiciliario por el uso de cocinas con combustible de biomasa, donde la exposición excesiva a PM 2,5 dentro de las casas es responsable de aproximadamente 3000 muertes prematuras anuales entre adultos, con otro número desconocido de muertes entre niños debido a infecciones respiratorias. La contaminación del agua tiene como principales causas los desagües vertidos directamente a los ríos, minerales (arsénico) de varias fuentes, y fallas de las plantas de tratamiento. En el Perú, el cambio climático puede impactar en la frecuencia y severidad del fenómeno de El Niño oscilación del sur (ENSO) que se ha asociado con un incremento en los casos de enfermedades como cólera, malaria y dengue. El cambio climático incrementa la temperatura y puede extender las áreas afectadas por enfermedades transmitidas por vectores, además de tener efecto en la disponibilidad del agua y en la contaminación del aire. En conclusión, el Perú, pasa por una transición de factores de riesgo ambientales, donde coexisten riesgos tradicionales y modernos, y persisten los problemas infecciosos y crónicos, algunos de los cuales se asocian con problemas de contaminación de agua y de aire. PMID:25418656
Ercit, Kyla; Martinez-Novoa, Andrew; Gwynne, Darryl T
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.
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
Squarza, S; Rossi, U G; Torcia, P; Cariati, M
A 16-year-old boy had a past medical history of primary hypogonadism, due to bilateral anorchia. He presented with gallstones located in the gallbladder and a mild dilatation of the intrahepatic biliary tree. The histology study reported cholesterol gallstones. The patient had been treated with testosterone replacement therapy since infancy. We suggest a possible correlation between testosterone replacement therapy and the presence of cholesterol gallstones. Copyright © 2018 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.
este artículo discute brevemente la prevalencia de caries, la naturaleza multifactorial de su etiología, el riesgo de caries y el papel y eficacia del fluoruro. Resalta también la investigación sobre el metabolismo bacteriano, que ha aportado conocimientos sobre la defensa natural oral contra la caries y la base para el desarrollo de una nueva tecnología para la prevención diaria y el tratamiento de la caries. Por último, se resume la evidencia que respalda que la tecnología complementa y mejora la eficacia anti-caries de la crema dental con fluoruro. los datos globales muestran que a pesar de la exitosa introducción del fluoruro, la caries dental es una enfermedad prevalente. La experiencia de caries depende del balance entre el consumo de azúcares, la higiene oral y el uso del fluoruro. Hay tres conceptos científicos que son fundamentales en las nuevas mediciones para detectar, tratar y monitorear la caries: (1) la caries dental es un proceso dinámico, (2) la caries dental es un proceso continuo de etapas que van desde reversible (pre-clínica) hasta irreversible (lesiones clínicamente detectables), y (3) el proceso de la caries es un balance de factores patológicos y protectores que pueden modularse para el manejo de la caries. El fluoruro funciona como factor protector al detener y revertir el proceso de la caries, pero el fluoruro no previene los factores patológicos que inician el proceso. Se ha identificado una tecnología novedosa, basada en arginina y un compuesto insoluble de calcio, que está dirigida a la placa dental para prevenir la iniciación del proceso de caries al reducir los factores patológicos. Como los mecanismos de acción de la arginina y el fluoruro son altamente complementarios, se ha desarrollado un nuevo dentífrico que combina la arginina y el fluoruro, y se ha probado clínicamente que brinda una prevención superior contra la caries. Copyright © 2013 Elsevier Ltd. All rights reserved.
van Gameren, Edwin
Se analizan los factores determinantes de la participación en la fuerza de trabajo de la póblacion mexicana de 50 años o más, con datos de la Encuesta nacional sobre salud y envejecimiento en México, ENASEM. Se estudió en particular la importancia de la salud en la decisión sobre la participación, tomando en cuenta la endogeneidad potencial de la salud. Los resultados indican que una mejor salud causa un mayor apego al mercado laboral. No se encontró evidencia clara de que el empleo afecte la salud, pero no puede descartarse que los efectos de las malas condiciones laborales y la justificación se eliminen mutuamente. Existen indicadores de que la autoevaluación de la salud no captura todos los aspectos relevantes de la salud. En la toma de decisiones para establecer políticas, la importancia directa de las circunstancias financieras podría ser más relevante que el papel de la salud. The determinants of the labor force participation of people in Mexico aged 50 and over are analyzed using data of the Mexican Health and Aging Study (MHAS). In particular we study the importance of health in the participation decision, taking into account the potential endogeneity of health. The results indicate that a better health causes a stronger attachment to the labor market. We find no clear evidence that employment affects health, but it cannot be ruled out that the effects of bad labor circumstances and justification eliminate each other. There are indications that self-assessed health does not capture all relevant aspects of health. For policy decisions the direct importance of financial circumstances could be more relevant than the role of health. PMID:29375171
van Gameren, Edwin
Se analizan los factores determinantes de la participación en la fuerza de trabajo de la póblacion mexicana de 50 años o más, con datos de la Encuesta nacional sobre salud y envejecimiento en México, ENASEM. Se estudió en particular la importancia de la salud en la decisión sobre la participación, tomando en cuenta la endogeneidad potencial de la salud. Los resultados indican que una mejor salud causa un mayor apego al mercado laboral. No se encontró evidencia clara de que el empleo afecte la salud, pero no puede descartarse que los efectos de las malas condiciones laborales y la justificación se eliminen mutuamente. Existen indicadores de que la autoevaluación de la salud no captura todos los aspectos relevantes de la salud. En la toma de decisiones para establecer políticas, la importancia directa de las circunstancias financieras podría ser más relevante que el papel de la salud. The determinants of the labor force participation of people in Mexico aged 50 and over are analyzed using data of the Mexican Health and Aging Study (MHAS). In particular we study the importance of health in the participation decision, taking into account the potential endogeneity of health. The results indicate that a better health causes a stronger attachment to the labor market. We find no clear evidence that employment affects health, but it cannot be ruled out that the effects of bad labor circumstances and justification eliminate each other. There are indications that self-assessed health does not capture all relevant aspects of health. For policy decisions the direct importance of financial circumstances could be more relevant than the role of health.
data) The Honduran electric company, Empresa Nacional de Energia Electrica (ENEE) generates power and operates the national transmission and...CDF Cumulative Distribution Function DoD Department of Defense ENEE Empresa Nacional de Energia Electrica EUPW Escalating Uniform Present Worth...generators with the fuel either purchased from the local population or transported from remote fuel depots. This incurs a significant cost for the
Puterka, Gary J; Scott, J Nicholson; Brown, Michael J; Hammon, R W
Three Diuraphis species, Diuraphis frequens (Walker), Diuraphis mexicana (McVicar Baker), and Diuraphis tritici (Gillette), were known to exist in the United States before the 1986 appearance of the Russian wheat aphid, Diuraphis noxia Kurdjumov. The Russian wheat aphid soon became a significant pest of wheat although other endemic Diuraphis species were known to infest wheat. Wheat and barley entries resistant and susceptible to Russian wheat aphid biotype 2 were evaluated against all four Diuraphis species to determine their host interrelationships. Leaf chlorosis, leaf roll, leaf number, plant height, and infestation levels were assessed 21 d after the plants were infested by aphids in a no-choice caged environment. D. mexicana was unable to survive on wheat by 21 d after infestation and effects on the plant damage variables were negligible. D. frequens survived at low levels on resistant and susceptible plant entries and had a low impact on plant damage and growth. Russian wheat aphid biotype 2 and D. tritici were damaged most wheat and barley lines except the Russian wheat aphid biotype 2-resistant wheat lines containing genes from Dn7, STARS 2414-11, and CI2401; and resistant barley containing genes from STARS 9577B and 9301B. Russian wheat aphid biotype 2 and D. tritici reduced the growth of resistant plants by 25-50% and susceptible entries by 65-75%. Reductions at this level are typical under no-choice studies but resistant cultivars do not have these reductions under field conditions. The Russian wheat aphid biotype 2 resistant wheat lines would be effective in managing both wheat pest species.
Rani, Asha; Sharma, Anil; Adak, Tridibes; Bhatnagar, Raj K
A Gram-negative, aerobic, golden yellow, rod-shaped bacterium, a strain designated ICGEB-L15(T), was isolated from the larval midgut of Anopheles stephensi captured in District Jhajjar, Haryana, India. The strain ICGEB-L15(T) grows at 30-50°C (optimum 30-37°C), pH 6.5-8.5 (optimum 7.0-8.0) and in the presence of 2% NaCl. The major fatty acids were iso-C(15:0) (22.5% of total fatty acid), anteiso-C(15:0) (16.5%), iso-C(17:1) 9c (10.3%), iso-C(16:0) (7.3%), C(16:0) (6.1%), and iso-C(11:0) (5.3%). The strain showed the highest 16S rRNA gene sequence similarities with the type strains Pseudoxanthomonas daejeonensis KCTC 12207(T) (97.4%), Pseudoxanthomonas kaohsiungensis J36(T) (97.17%), and Pseudoxanthomonas mexicana AMX 26B(T) (97.11%). The DNA relatedness between ICGEB-L15(T) and Pseudoxanthomonas daejeonensis KCTC 12207(T), Pseudoxanthomonas kaohsiungensis J36(T) and Pseudoxanthomonas mexicana AMX 26B(T) was 24.5%, 28.2%, and 33.6%, respectively. The G+C content of genomic DNA was 69.9 mol%. The major isoprenoid quinone of strain ICGEB-L15(T) was Q-8. The strain ICGEB-L15(T) represents a novel species of the genus Pseudoxanthomonas based on physiological, biochemical and phylogenetic properties; therefore, the name Pseudoxanthomonas icgebensis sp. nov. is proposed. The type strain is ICGEB-L15(T) (=KACC 14090(T) =DSM 22536(T)).
Isaac-Márquez, A P; Talamás-Rohana, P; Galindo-Sevilla, N; Gaitan-Puch, S E; Díaz-Díaz, N A; Hernández-Ballina, G A; Lezama-Dávila, C M
We evaluated, for the first time, the leishmanicidal potential of decanethiol functionalized silver nanoparticles (AgNps-SCH) on promastigotes and amastigotes of different strains and species of Leishmania: L. mexicana and L. major isolated from different patients suffering from localized cutaneous leishmaniasis (CL) and L. mexicana isolated from a patient suffering from diffuse cutaneous leishmaniasis (DCL). We recorded the kinetics of promastigote growth by daily parasite counting for 5 days, promastigote mobility, parasite reproduction by CFSE staining's protocol and promastigote killing using the propidium iodide assay. We also recorded IC 50 's of promastigotes and amastigotes, therapeutic index, and cytotoxicity by co-culturing macrophages with AgNps-SCH or sodium stibogluconate (Sb) used as reference drug. We used Sb as a reference drug since it is used as the first line treatment for all different types of leishmaniasis. At concentrations 10,000 times lower than those used with Sb, AgNps-SCH had a remarkable leishmanicidal effect in all tested strains of parasites and there was no toxicity to J774A.1 macrophages since > 85% were viable at the concentrations used. Therapeutic index was about 20,000 fold greater than the corresponding one for Sb treated cells. AgNps-SCH inhibited > 80% promastigote proliferation in all tested parasites. These results demonstrate there is a high leishmanicidal potential of AgNps-SCH at concentrations of 0.04 µM. Although more studies are needed, including in vivo testing of AgNps-SCH against different types of leishmaniasis, they can be considered a potential new treatment alternative.
Hashiguchi, Yoshihisa; Gomez L, Eduardo A; Cáceres, Abraham G; Velez, Lenin N; Villegas, Nancy V; Hashiguchi, Kazue; Mimori, Tatsuyuki; Uezato, Hiroshi; Kato, Hirotomo
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.
Toledo-Hernández, R A; Ruíz-Toledo, J; Toledo, J; Sánchez, D
Development of alternative strategies for pest control with reduced effect on beneficial organisms is a priority given the increasing global loss of biodiversity. Biological control with entomopathogenic fungi arises as a viable option to control insect pests. However, few studies have focused on the consequences of using these organisms on pollinators other than the honey bee (Apis mellifera L.) or bumble bees (Bombus spp). We evaluated the pathogenicity of commercial formulations of three widely used entomopathogenic fungi, Metarhizium anisopliae (Metschnikoff) Sorokin, Beauveria bassiana Vuillemin, and Isaria fumosorosea (Wize), to three species of stingless bees: Tetragonisca angustula Latreille, Scaptotrigona mexicana Guérin-Meneville, and Melipona beecheii Bennett. Bioassays consisted of exposing groups of bees to the recommended field concentration of each fungus using a microspray tower under laboratory conditions. Susceptibility to fungi varied greatly among species. Isaria fumosorosea (strain Ifu-lu 01) and the two formulations of B. bassiana (Bea-TNK and BotanicGard) caused <30.3% mortality in all bee species. Metarhizium anisopliae (Meta-TNK and strain Ma-lu 01) was highly active against T. angustula (94.2% mortality) and moderately active against M. beecheii (53.0% mortality) and S. mexicana (38.9% mortality). Though our laboratory-derived results suggest a moderate to high impact of these entomopathogenic fungi on stingless bees, further field studies are required to support this finding. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: email@example.com.
Calvopina, Manuel; Armijos, Rodrigo X; Marco, Jorge D; Uezato, Hiroshi; Kato, Hirotomo; Gomez, Eduardo A; Korenaga, Masataka; Barroso, Paola A; Mimori, Tatsuyuki; Cooper, Philip J; Nonaka, Shigeo; Hashiguchi, Yoshihisa
Background Determinants of the clinical presentation of the leishmaniases are poorly understood but Leishmania species and strain differences are important. To examine the relationship between clinical presentation, species and isoenzyme polymorphisms, 56 Leishmania isolates from distinct presentations of American tegumentary leishmaniasis (ATL) from Ecuador were analyzed. Methods Isolates were characterized by multilocus enzyme electrophoresis for polymorphisms of 11 isoenzymes. Patients were infected in four different ecologic regions: highland and lowland jungle of the Pacific coast, Amazonian lowlands and Andean highlands. Results Six Leishmania species constituting 21 zymodemes were identified: L. (Viannia) panamensis (21 isolates, 7 zymodemes), L. (V.) guyanensis (7 isolates, 4 zymodemes), L. (V.) braziliensis (5 isolates, 3 zymodemes), L. (Leishmania) mexicana (11 isolates, 4 zymodemes), L. (L.) amazonensis (10 isolates, 2 zymodemes) and L. (L.) major (2 isolates, 1 zymodeme). L. panamensis was the species most frequently identified in the Pacific region and was associated with several clinical variants of cutaneous disease (CL); eight cases of leishmaniasis recidiva cutis (LRC) found in the Pacific highlands were associated with 3 zymodemes of this species. Mucocutaneous leishmaniasis found only in the Amazonian focus was associated with 3 zymodemes of L. braziliensis. The papular variant of CL, Uta, found in the Andean highlands was related predominantly with a single zymodeme of L. mexicana. Conclusion Our data show a high degree of phenotypic variation within species, and some evidence for associations between specific variants of ATL (i.e. Uta and LRC) and specific Leishmania zymodemes. This study further defines the geographic distribution of Leishmania species and clinical variants of ATL in Ecuador. PMID:16968553
Geric Stare, Barbara; Fouville, Didier; Širca, Saša; Gallot, Aurore; Urek, Gregor; Grenier, Eric
While pectate lyases are major parasitism factors in plant-parasitic nematodes, there is little information on the variability of these genes within species and their utility as pathotype or host range molecular markers. We have analysed polymorphisms of pectate lyase 2 (pel-2) gene, which degrades the unesterified polygalacturonate (pectate) of the host cell-wall, in the genus Globodera. Molecular variability of the pel-2 gene and the predicted protein was evaluated in populations of G. rostochiensis, G. pallida, G. "mexicana" and G. tabacum. Seventy eight pel-2 sequences were obtained and aligned. Point mutations were observed at 373 positions, 57% of these affect the coding part of the gene and produce 129 aa replacements. The observed polymorphism does not correlate either to the pathotypes proposed in potato cyst nematodes (PCN) or the subspecies described in tobacco cyst nematodes. The trees reveal a topology different from the admitted species topology as G. rostochiensis and G. pallida sequences are more similar to each other than to G. tabacum. Species-specific sites, potentially applicable for identification, and sites distinguishing PCN from tobacco cyst nematodes, were identified. As both G. rostochiensis and G. pallida display the same host range, but distinct from G. tabacum, which cannot parasitize potato plants, it is tempting to speculate that pel-2 genes polymorphism may be implicated in this adaptation, a view supported by the fact that no active pectate lyase 2 was found in G. "mexicana", a close relative of G. pallida that is unable to develop on cultivated potato varieties.
Carmona-Sánchez, R; Icaza-Chávez, M E; Bielsa-Fernández, M V; Gómez-Escudero, O; Bosques-Padilla, F; Coss-Adame, E; Esquivel-Ayanegui, F; Flores-Rendón, Á R; González-Martínez, M A; Huerta-Iga, F; López-Colombo, A; Méndez-Gutiérrez, T H; Noble-Lugo, A; Nogueira-de Rojas, J R; Raña-Garibay, R H; Remes-Troche, J M; Roesch-Dietlen, F; Schmulson, M J; Soto-Pérez, J C; Tamayo, J L; Uscanga, L F; Valdovinos, M Á; Valerio-Ureña, J; Zavala-Solares, M R
Since the publication in 2009 of the Guidelines on the Diagnosis and Treatment of Irritable Bowel Syndrome of the Asociación Mexicana de Gastroenterología (2009 Guidelines), there have been significant advances in our knowledge of the epidemiology, pathophysiology, diagnosis, and treatment of this disease. To present a consensus review of the most current knowledge of IBS, updating the 2009 Guidelines by incorporating new internationally published scientific evidence, with a special interest in Mexican studies. The PubMed literature from January 2009 to March 2015 was reviewed and complemented through a manual search. Articles in English and Spanish were included and preference was given to consensuses, guidelines, systematic reviews, and meta-analyses. Statements referring to the different aspects of the disease were formulated and voted upon by 24 gastroenterologists employing the Delphi method. Once a consensus on each statement was reached, the quality of evidence and strength of recommendation were determined through the GRADE system. Forty-eight statements were formulated, updating the information on IBS and adding the complementary data that did not appear in the 2009 Guidelines regarding the importance of exercise and diet, diagnostic strategies, and current therapy alternatives that were analyzed with more stringent scientific vigor or that emerged within the last 5 years. We present herein a consensus review of the most relevant advances in the study of IBS, updating and complementing the 2009 Guidelines. Several studies conducted in Mexico were included. Copyright © 2016 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.
Cintrón-Bou, Francheska; Varas-Díaz, Nelson; Marzán-Rodríguez, Melissa; Neilands, Torsten B.
Existe estigma relacionado al VIH. A las personas con VIH/SIDA-PCVS se les viola sus derechos y obstaculiza su bienestar mental/físico. Profesionales de la salud-PS son fuente de apoyo primordial, sin embargo estos/as le estigmatizan. Es útil adiestrar a PS en relación al estigma social. Implantamos la intervención para reducir el estigma relacionado al VIH/SIDA con 507 estudiantes de medicina. Resultó ser una intervención efectiva, hubo reducción en los niveles de estigma a partir de nuestra intervención y diferencias significativas con el grupo control (p≤.05). Generar espacios de adiestramiento para atender el estigma relacionado al VIH/SIDA es pertinente para la psicología comunitaria porque colaboramos en la reducción de actitudes estigmatizantes que afectan adversamente la prevención de nuevas infecciones, la adherencia al tratamiento antirretroviral y la calidad de vida. PMID:27829690
... determination that the action is warranted. Under specific facts, we may also issue a determination that the... the Center for Environmental Science Accuracy and Reliability, Empresas Del Bosque, and Coburn Ranch...
... President) 1000 Peachtree Street NE., Atlanta, Georgia 30309: 1. Banco De Credito E Inversiones, Empresas Juan Yarur S.A.C., Inversiones Petro S.A. Inversiones Baquio LTDA, Inversiones, Nueve, LTDA, and...
López, J. L.; Baltazar, C.; Torres, M.; Ruız, A.; Esparza, R.; Rosas, G.
The biosynthesis of silver nanoparticles using an aqueous extract of Agastache mexicana and Tecoma stans was carried out. The AgNO3 concentration and extract concentration was varied to evaluate their influence on the nanoparticles characteristics such as size and shape. Several characterization techniques were employed. UV-Vis spectroscopy revealed the surface plasmon resonance in the range of 400-500 nm. The X-Ray diffraction results showed that the nanoparticles have a face-centered cubic structure. SEM results confirmed the formation of silver nanoparticles with spherical morphologies. Finally, the antibacterial activity of silver nanoparticles was evaluated against Escherichia coli bacteria.
Lafontaine, J Donald; Walsh, J Bruce; Ferris, Clifford D
The genus Protorthodes McDunnough is revised to include 15 species including P. ustulata Lafontaine, Walsh & Ferris, sp. n., from southwestern United States, P. texicana Lafontaine, sp. n., from Texas and Mexico, and P. mexicana Lafontaine, sp. n., from Mexico. A new genus, Nudorthodes Lafontaine, Walsh & Ferris, is proposed for two species formerly included in Protorthodes, P. texana (Smith, 1900), comb. n., and P. variabilis (Barnes & McDunnough, 1912), comb. n., and N. molino Lafontaine, Walsh & Ferris, sp. n., described from southern Arizona. A key to species, descriptions, illustrations of adults and genitalia, and distribution maps are included.
Marenco-de la Cuadra, Beatriz; López-Ruiz, José Antonio; Tallón-Aguilar, Luis; López-Pérez, José; Oliva-Mompeán, Fernando
A gallstone colonic ileus is a very rare condition. The case is reported of an 87 year-old patient who came to the Emergency Department due to an intestinal obstruction of several days onset, which was caused by a gallstone affected sigmoid colon. Colonic gallstone ileus is a rare disease that usually occurs in older patients due to the passage of large gallstone directly from the gallbladder to colon, through a cholecystocolonic fistula. It has a high morbidity and mortality. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.
Boecken, Gerhard; Sunderkötter, Cord; Bogdan, Christian; Weitzel, Thomas; Fischer, Marcellus; Müller, Andreas; Löbermann, Micha; Anders, Gerlind; von Stebut, Esther; Schunk, Mirjam; Burchard, Gerd; Grobusch, Martin; Bialek, Ralf; Harms-Zwingenberger, Gundel; Fleischer, Bernhard; Pietras, Mathias; Faulde, Michael; Erkens, Kay
The incidence of cutaneous and mucocutaneous Leishmaniasis (CL/MCL) is increasing globally, also in Germany, although the cases are imported and still low in number. The current evidence for the different therapies has many limitations due to lack of sufficient studies on the different Leishmania species with differing virulence. So far there is no international gold standard for the optimal management. The aim of the German joint working group on Leishmaniasis, formed by the societies of Tropical Medicine (DTG), Chemotherapy (PEG) and Dermatology (DDG), was to establish a guideline for the diagnosis and treatment of CL and MCL in Germany, based on evidence (Medline search yielded 400 articles) and, where lacking, on consensus of the experts. As the clinical features do not necessarily reflect the involved Leishmania species and, as different parasite species and even geographically distinct strains of the same species may require different treatments or varying dosages or durations of therapy, the guidelines suggest for Germany to identify the underlying parasite prior to treatment. Because of relevant differences in prognosis and ensuing therapy species should be identified in i) New World CL/MCL (NWCL/ MCL) to distinguish between L. mexicana-complex and subgenus Viannia, ii) in suspected infections with L. mexicana-complex to distinguish from L. amazonensis, and iii) in Old World CL (OWCL) to distinguish between L. infantum and L. major, L. tropica, or L. aethiopica. A state-of-the-art diagnostic algorithm is presented. For recommendations on localized and systemic drug treatment and physical procedures, data from the accessible literature were adjusted according to the involved parasite species and a clinical differentiation into uncomplicated or complex lesions. Systemic therapy was strictly recommended for i) complex lesions (e. g. > 3 infected lesions, infections in functionally or cosmetically critical areas such as face or hands, presence of lymphangitis
Empresas pequeñas de manufactura que cumplen con regulaciones ambientales e implementan buenas practicas de manejo, pueden mantenerse a la vanguardia respecto a prepararse para eventos climáticos extremos en el futuro.
Revision curricular a partir de un analisis comparativo de las discrepancias en los curriculos de una escuela de optometria en Puerto Rico con las competencias requeridas para las agencias de revalida y acreditacion 2004
Rivera Pacheco, Andres
El proposito de esta investigacion, un estudio cualitativo de caso, fue comparar y contrastar el curriculo vigente de la Escuela de Optometria de la UIAPR con las competencias y estandares requeridos por las agencias de acreditacion y de revalida. Con este proposito, decidimos realizar una revision y un analisis de documentos: el prontuario de cada uno de los cursos de los curriculos implantados en el 1993 y en el 2001; las competencias y estandares establecidos por las agencias de revalida y de acreditacion; y las estadisticas en las que se analiza el porcentaje de estudiantes que aprueban cada una de las partes de los examenes de revalida entre el 1998 al 2003. Se realizaron entrevistas dirigidas para dar apoyo y complementar la revision y el analisis de estos documentos. Los participantes de las entrevistas fueron tres estudiantes de la clase de optometria del 2004 (ultima clase del curriculo del 1993); tres estudiantes de la clase de optometria del 2005 (primera clase graduanda del curriculo vigente) y tres profesores y/o directores de los Departamentos de Ciencias Basicas, Ciencias Clinicas y Cuidado al Paciente. Esta investigacion se enmarco en el modelo de evaluacion curricular de discrepancia de Malcolm Provus y en el modelo de desarrollo basado en competencias. Uno de los hallazgos mas importantes del estudio es que los cambios que se implantaron al curriculo del 2001 no han logrado que los estudiantes mejoren su ejecucion en los examenes de revalida. Por otro lado, se encontro que el curriculo vigente atiende completamente los estandares de la practica de Optometria, pero no las competencias. Esta informacion fue validada mediante el uso de una tabla de cotejo para el analisis de los cursos y de la informacion obtenida de las entrevistas. El estudio determina y concluye que existen discrepancias entre los prontuarios de los cursos del curriculo y las competencias requeridas por la agencia de revalida. Segundo, que el Departamento de Ciencias Basicas es el
Gomez-Escobar, Natalia; Bennett, Clare; Prieto-Lafuente, Lidia; Aebischer, Toni; Blackburn, Clare C; Maizels, Rick M
Background Parasites exploit sophisticated strategies to evade host immunity that require both adaptation of existing genes and evolution of new gene families. We have addressed this question by testing the immunological function of novel genes from helminth parasites, in which conventional transgenesis is not yet possible. We investigated two such novel genes from Brugia malayi termed abundant larval transcript (alt), expression of which reaches ~5% of total transcript at the time parasites enter the human host. Results To test the hypothesis that ALT proteins modulate host immunity, we adopted an alternative transfection strategy to express these products in the protozoan parasite Leishmania mexicana. We then followed the course of infection in vitro in macrophages and in vivo in mice. Expression of ALT proteins, but not a truncated mutant, conferred greater infectivity of macrophages in vitro, reaching 3-fold higher parasite densities. alt-transfected parasites also caused accelerated disease in vivo, and fewer mice were able to clear infection of organisms expressing ALT. alt-transfected parasites were more resistant to IFN-γ-induced killing by macrophages. Expression profiling of macrophages infected with transgenic L. mexicana revealed consistently higher levels of GATA-3 and SOCS-1 transcripts, both associated with the Th2-type response observed in in vivo filarial infection. Conclusion Leishmania transfection is a tractable and informative approach to determining immunological functions of single genes from heterologous organisms. In the case of the filarial ALT proteins, our data suggest that they may participate in the Th2 bias observed in the response to parasite infection by modulating cytokine-induced signalling within immune system cells. PMID:15788098
Bosques-Padilla, F J; Remes-Troche, J M; González-Huezo, M S; Pérez-Pérez, G; Torres-López, J; Abdo-Francis, J M; Bielsa-Fernandez, M V; Camargo, M Constanza; Esquivel-Ayanegui, F; Garza-González, E; Hernández-Guerrero, A I; Herrera-Goepfert, R; Huerta-Iga, F M; Leal-Herrera, Y; Lopéz-Colombo, A; Ortiz-Olvera, N X; Riquelme-Pérez, A; Sampieri, C L; Uscanga-Domínguez, L F; Velasco, J A Velarde-Ruiz
Important advances have been made since the last Mexican consensus on the diagnosis and treatment of Helicobacter pylori (H. pylori) infection was published in 2007. Therefore, the Asociación Mexicana de Gastroenterología summoned 20 experts to produce "The Fourth Mexican Consensus on Helicobacter pylori". From February to June 2017, 4 working groups were organized, a literature review was performed, and 3 voting rounds were carried out, resulting in the formulation of 32 statements for discussion and consensus. From the ensuing recommendations, it was striking that Mexico is a country with a low-to-intermediate risk for gastric cancer, despite having a high prevalence of H. pylori infection. It was also corroborated that peptic ulcer disease, premalignant lesions, and histories of gastric cancer and mucosa-associated lymphoid tissue lymphoma should be considered clear indications for eradication. The relation of H. pylori to dyspeptic symptoms continues to be controversial. Eradication triple therapy with amoxicillin, clarithromycin, and a proton pump inhibitor should no longer be considered first-line treatment, with the following 2 options proposed to take its place: quadruple therapy with bismuth (proton pump inhibitor, bismuth subcitrate, tetracycline, and metronidazole) and quadruple therapy without bismuth (proton pump inhibitor, amoxicillin, clarithromycin, and metronidazole). The need for antimicrobial sensitivity testing when 2 eradication treatments have failed was also established. Finally, the promotion of educational campaigns on the diagnosis and treatment of H. pylori for both primary care physicians and the general population were proposed. Copyright © 2018 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.
Carmona-Sánchez, R; Gómez-Escudero, O; Zavala-Solares, M; Bielsa-Fernández, M V; Coss-Adame, E; Hernández-Guerrero, A I; Huerta-Iga, F; Icaza-Chávez, M E; Lira-Pedrín, M A; Lizárraga-López, J A; López-Colombo, A; Noble-Lugo, A; Pérez-Manauta, J; Raña-Garibay, R H; Remes-Troche, J M; Tamayo, J L; Uscanga, L F; Zamarripa-Dorsey, F; Valdovinos Díaz, M A; Velarde-Ruiz Velasco, J A
Since the publication of the 2007 dyspepsia guidelines of the Asociación Mexicana de Gastroenterología, there have been significant advances in the knowledge of this disease. A systematic search of the literature in PubMed (01/2007 to 06/2016) was carried out to review and update the 2007 guidelines and to provide new evidence-based recommendations. All high-quality articles in Spanish and English were included. Statements were formulated and voted upon using the Delphi method. The level of evidence and strength of recommendation of each statement were established according to the GRADE system. Thirty-one statements were formulated, voted upon, and graded. New definition, classification, epidemiology, and pathophysiology data were provided and include the following information: Endoscopy should be carried out in cases of uninvestigated dyspepsia when there are alarm symptoms or no response to treatment. Gastric and duodenal biopsies can confirm Helicobacter pylori infection and rule out celiac disease, respectively. Establishing a strong doctor-patient relationship, as well as dietary and lifestyle changes, are useful initial measures. H2-blockers, proton-pump inhibitors, prokinetics, and antidepressants are effective pharmacologic therapies. H.pylori eradication may be effective in a subgroup of patients. There is no evidence that complementary and alternative therapies are beneficial, with the exception of Iberogast and rikkunshito, nor is there evidence on the usefulness of prebiotics, probiotics, or psychologic therapies. The new consensus statements on dyspepsia provide guidelines based on up-to-date evidence. A discussion, level of evidence, and strength of recommendation are presented for each statement. Copyright © 2017 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.
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
Abreu, D. P. B.; Almeida-Paes, R.; Brilhante, R. S. N.; Chakrabarti, A.; Córdoba, S.; Gonzalez, G. M.; Guarro, J.; Johnson, E. M.; Kidd, S. E.; Pereira, S. A.; Rozental, S.; Szeszs, M. W.; Ballesté Alaniz, R.; Bonifaz, A.; Bonfietti, L. X.; Borba-Santos, L. P.; Capilla, J.; Colombo, A. L.; Dolande, M.; Isla, M. G.; Melhem, M. S. C.; Mesa-Arango, A. C.; Oliveira, M. M. E.; Panizo, M. M.; Pires de Camargo, Z.; Zancope-Oliveira, R. M.; Turnidge, J.
ABSTRACT Clinical and Laboratory Standards Institute (CLSI) conditions for testing the susceptibilities of pathogenic Sporothrix species to antifungal agents are based on a collaborative study that evaluated five clinically relevant isolates of Sporothrix schenckii sensu lato and some antifungal agents. With the advent of molecular identification, there are two basic needs: to confirm the suitability of these testing conditions for all agents and Sporothrix species and to establish species-specific epidemiologic cutoff values (ECVs) or breakpoints (BPs) for the species. We collected available CLSI MICs/minimal effective concentrations (MECs) of amphotericin B, five triazoles, terbinafine, flucytosine, and caspofungin for 301 Sporothrix schenckii sensu stricto, 486 S. brasiliensis, 75 S. globosa, and 13 S. mexicana molecularly identified isolates. Data were obtained in 17 independent laboratories (Australia, Europe, India, South Africa, and South and North America) using conidial inoculum suspensions and 48 to 72 h of incubation at 35°C. Sufficient and suitable data (modal MICs within 2-fold concentrations) allowed the proposal of the following ECVs for S. schenckii and S. brasiliensis, respectively: amphotericin B, 4 and 4 μg/ml; itraconazole, 2 and 2 μg/ml; posaconazole, 2 and 2 μg/ml; and voriconazole, 64 and 32 μg/ml. Ketoconazole and terbinafine ECVs for S. brasiliensis were 2 and 0.12 μg/ml, respectively. Insufficient or unsuitable data precluded the calculation of ketoconazole and terbinafine (or any other antifungal agent) ECVs for S. schenckii, as well as ECVs for S. globosa and S. mexicana. These ECVs could aid the clinician in identifying potentially resistant isolates (non-wild type) less likely to respond to therapy. PMID:28739796
Mukhopadhyay, Amitabha; Chaudhuri, Gautam; Arora, Sunil K.; Sehgal, Shobha; Basu, Sandip K.
Methotrexate coupled to maleylated bovine serum albumin was taken up efficiently through the ``scavenger'' receptors present on macrophages and led to selective killing of intracellular Leishmania mexicana amazonensis amastigotes in cultured hamster peritoneal macrophages. The drug conjugate was nearly 100 times as effective as free methotrexate in eliminating the intracellular parasites. Furthermore, in a model of experimental cutaneous leishmaniasis in hamsters, the drug conjugate brought about more than 90% reduction in the size of footpad lesions within 11 days. In contrast, the free drug at a similar concentration did not significantly affect lesion size. These studies demonstrate the potential of receptor-mediated drug delivery in the therapy of macrophage-associated diseases.
We reviewed the literature covering the medical movement in 1964-1965, which began on November 26, 1964 with the ISSSTE November 20 Hospital scholarship protest and the emergence of the Mexican Resident Interns Physicians Association (Asociación Mexicana de Médicos Residentes e Internos, AMMRI) and the Mexican Medical Alliance (Alianza de Médicos Mexicanos, AMM). We describe four work stoppages, two protest marches, the takeover of hospitals by the police, four interviews with Licenciado Gustavo Diaz Ordaz and his first presidential report. After that, attacks in the press, harassment, and repression provoked the weakening of the movement that ended in the AMM assembly on January 18, 1966.
Immigrant inviability, where individuals from foreign, ecologically divergent habitats are less likely to survive, can restrict gene flow among diverging populations and result in speciation. I investigated whether a predatory aquatic insect (Belostoma sp.) selects against migrants between cave and surface populations of a fish (Poecilia mexicana). Cavefish were more susceptible to attacks in the light, whereas surface fish were more susceptible in darkness. Environmentally dependent susceptibility to attacks may thus contribute to genetic and phenotypic differentiation between the populations. This study highlights how predation—in this case in conjunction with differences in other environmental factors—can be an important driver in speciation. PMID:19443506
Mandrini, C. H.; Démoulin, P.; van Driel-Gesztelyi, L.; Schmieder, B.; Bagalá, L. G.; Rovira, M. G.
Se han obtenido observaciones desde Tierra (Hα y magnetogramas) coordinadas con el Soft X-ray Telescope (SXT), a bordo del satélite japonés Yohkoh, de una región activa bipolar en decaimiento. Estos datos constituyen la base para el estudio de un punto brillante en rayos X (PBX) y de la actividad relacionada con el mismo en distintas capas de la atmósfera solar. Las observaciones muestran que el PBX está relacionado con la aparición de un bipolo menor (~ 1020 Mx) y que su abrillantamiento continuo, así como sus aumentos de brillo esporádicos (``fulguraciones"), son el resultado de la reconexión entre el pequeño arco emergente (visto en Hα como un sistema de filamentos arqueados, SFA) y arcos mayores asociados al campo facular preexistente. Se ha extrapolado el campo magnético observado en la aproximación libre de fuerzas lineal y se ha seguido su evolución a lo largo de la vida del PBX. Se ha calculado la posición de las cuasiseparatrices (CSs) a partir del campo modelado. Las líneas de campo extrapoladas, cuyas bases fotosféricas se encuentran a ambos lados de las CSs, están de acuerdo con las estructuras cromosféricas y coronales observadas. Se ha calculado el espesor de la CD ubicada a lo largo de la polaridad negativa emergente, encontrándose que su variación está de acuerdo con la evolución de la intensidad del PBX; la CS es muy delgada durante la vida del PBX (~ 100 m), mientras que su espesor aumenta considerablemente (>= 10^4 m) cuando el PBX desaparece de las imágenes del SXT. Estos resultados señalan que el abrillantamiento y las ``fulguraciones" de este PBX se deben al proceso de reconexión en 3D que tiene lugar en las CSs.
Interview, December 1996. Perea, Mauricio, La CFI Invierte En La Empresa Encargada De Las Comunicaciones Por Satelite En Argentina. Corporacion Financiera...1 Attn: Servicio de Comunicaciones Navales 630 Indiana Avenue NW Washington, D.C. 20004-2989 13. A rgentine N
Marin, Johana; Urrea, Daniel; Muskus, Carlos; Echeverry, María Clara; Mejía, Ana María; Triana, Omar
Introducción. La leishmaniasis cutánea es una enfermedad causada por parásitos del género Leishmania que tiene gran incidencia en Colombia. El diagnóstico y la identificación de la especie infecciosa son factores críticos en el momento de escoger e iniciar el tratamiento. Actualmente, los métodos de diagnóstico y tipificación requieren procedimientos complejos, por lo que es necesario validar nuevos marcadores moleculares y métodos que simplifiquen el proceso.Objetivo. Desarrollar una herramienta basada en la reacción en cadena de la polimerasa (PCR) con curvas de fusión (High Resolution Melting; PCR-HRM) para el diagnóstico y tipificación de las tres especies de Leishmania de importancia epidemiológica en casos de leishmaniasis cutánea en Colombia.Materiales y métodos. Los genomas de Leishmania panamensis, L. braziliensis y L. guyanensis se compararon mediante métodos bioinformáticos. Las regiones específicas de especie identificadas se validaron mediante PCR. Para los marcadores seleccionados se diseñó una PCR-HRM y se estimaron algunos parámetros de validez y seguridad usando aislamientos de pacientes colombianos caracterizados previamente mediante PCR y análisis de polimorfismos en la longitud de los fragmentos de restricción (Restriction Fragment Length Polymorphism - RFLP; PCR-RFLP) del gen hsp70.Resultados. El análisis genómico comparativo mostró 24 regiones específicas de especie. Sin embargo, la validación mediante PCR solo identificó un marcador específico para cada especie de Leishmania. Los otros marcadores mostraron amplificación cruzada. El límite de detección para los tres marcadores seleccionados fue de un parásito, mientras que la sensibilidad, la especificidad, el valor predictivo positivo y el negativo fueron de 91,4, 100, 100 y 75 %, respectivamente.Conclusiones. Las tres regiones seleccionadas pueden emplearse como marcadores moleculares en el diagnóstico y tipificación de las especies causantes de la
Bahia, Ligia; Scheffer, Mario; Tavares, Leandro Reis; Braga, Iale Falleiros
The concentration and internationalization of health plan companies in Brazil gave them a clearly financial face. Based on the need to understand the health care industry's capital accumulation patterns, the current study examines health plan companies' expansion strategies through the classification of their supply and demand characteristics by recent historical periods and an analysis of recent shareholding trends in one of the leading corporations in the Brazilian health care industry. The 1960s to 2000s witnessed changes in the scale of demands for health plans and adherence by companies to long-term accumulation strategies. Beginning in the early 21st century, changes in the shareholding structures of the largest Brazilian company, consistent with the financialization of its accumulation regime, resulted in the rapid multiplication of its capital. Deepening segmentation of the health care system in a context marked by the downturn in the national economy challenges the preservation of public subsidies for private health plans. Resumo: A concentração e internacionalização de empresas de planos de saúde no Brasil conferiram-lhes feição financeira. Considerando a necessidade de compreender os padrões de acumulação desse setor, o trabalho examina estratégias de expansão das empresas de planos de saúde por meio da periodização de atributos da oferta e demanda e exame da trajetória patrimonial recente de um dos grandes grupos do setor. Entre os anos 1960 e 2000, ocorreram alterações na escala das demandas por planos de saúde e adesão das empresas a estratégias de acumulação de longo prazo. A partir do século XXI, as alterações nas estruturas societárias da maior empresa brasileira, compatíveis com o regime de acumulação financeirizada, resultaram na multiplicação de seu capital em um curto intervalo de tempo. O aprofundamento da segmentação do sistema de saúde, em um contexto marcado pela desaceleração da economia, questiona a
College), and he has taught visiting seminars at American University in Cairo, and Instituto de Empresas in Madrid. Dr. Reed retired after 21 years... Transportation –Federal Aviation Administration and will use historical program data to derive recommended staffing levels for major acquisition
Extrafloral nectar (EFN) mediates food-for-protection mutualisms between plants and ants. Ant-plant mutualisms are keystone associations, occurring within a complex web of biotic interactions. As such, these interactions may affect plant fitness in a number of ways, both positive and negative. In S...
Palacios, Maura; Arias-Rodriguez, Lenin; Plath, Martin; Eifert, Constanze; Lerp, Hannes; Lamboj, Anton; Voelker, Gary; Tobler, Michael
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
Alvarez-Mercado, José Manuel; Ibarra-Velarde, Froylán; Alonso-Díaz, Miguel Ángel; Vera-Montenegro, Yolanda; Avila-Acevedo, José Guillermo; García-Bores, Ana María
Fasciolosis due to Fasciola hepatica is the most important hepatic disease in veterinary medicine. Its relevance is important because of the major economical losses to the cattle industry such as: reduction in milk, meat and wool production; miscarriages, anemia, liver condemnation and occasionally deaths, are estimated in billons of dollars. The emergence of fluke resistance due to over or under dosing of fasciolides as well as environmental damage produced by the chemicals eliminated in field have stimulated the need for alternative methods to control Fasciola hepatica. The aim of this study was to evaluate the in vitro anthelmintic effect of fifteen tropical plant extracts used in tradicional Mexican medicine, on newly excysted flukes of Fasciola hepatica. The flukes were exposed in triplicate at 500, 250 and 125 mg/L to each extract. The efficacy was assessed as the mortality rate based on the number of live and dead flukes after 24, 48 and 72 h post-exposure. The plants with anthelmintic effect were evaluated once again with a concentration of 375 mg/L in order to confirm the results and to calculate lethal concentrations at 50%, 90% and 99% (LC(50), LC(90), and LC(99)). Plant extracts of Lantana camara, Bocconia frutescens, Piper auritum, Artemisia mexicana and Cajanus cajan had an in vitro anthelmintic effect (P <0.05). The LC(50), LC(90) and LC(99) to A. mexicana, C. cajan and B. frutescens were 92.85, 210.44 and 410.04 mg/L, 382.73, 570.09 and 788.9 mg/L and 369.96, 529.94 and 710.34 mg/L, respectively. It is concluded that five tropical plant extracts had promising anthelmintic effects against F. hepatica. Further studies on toxicity and in vivo biological evaluation in ruminant models might help to determine the anthelmintic potential of these plant extracts.
Hamdi, Assia; Bero, Joanne; Beaufay, Claire; Flamini, Guido; Marzouk, Zohra; Vander Heyden, Yvan; Quetin-Leclercq, Joelle
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.
Salazar-Aranda, Ricardo; Pérez-López, Luis Alejandro; López-Arroyo, Joel; Alanís-Garza, Blanca Alicia; Waksman de Torres, Noemí
Traditional medicine has a key role in health care worldwide. Obtaining scientific information about the efficacy and safety of the plants from our region is one of the goals of our research group. In this report, 17 plants were selected and collected in different localities from northeast Mexico. The dried plants were separated into leaves, flowers, fruit, stems, roots and bark. Each part was extracted with methanol, and 39 crude extracts were prepared. The extracts were tested for their antimicrobial activity using three Gram-negative bacterial strains (Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii), three Gram-positive bacterial strains (Enterococcus faecalis and two Staphylococcus aureus strains), and seven clinically isolated yeasts (Candida albicans, C. krusei, C. tropicalis, C. parapsilosis and C. glabrata); their antioxidant activity was tested using a DPPH free radical assay. No activity against Gram-negative bacteria was observed with any extract up to the maximum concentration tested, 1000 μg ml(-1). We report here for the first time activity of Ceanothus coeruleus against S. aureus (flowers, minimal inhibitory concentration (MIC) 125 μg ml(-1)), C. glabrata (MICs 31.25 μg ml(-1)) and C. parapsilosis (MICs between 31.25 and 125 μg ml(-1)); Chrysanctinia mexicana against C. glabrata (MICs 31.25 μg ml(-1)); Colubrina greggii against E. faecalis (MICs 250 μg ml(-1)) and Cordia boissieri against C. glabrata (MIC 125 μg ml(-1)). Furthermore, this is the first report about antioxidant activity of extracts from Ceanothus coeruleus, Chrysanctinia mexicana, Colubrina greggii and Cyperus alternifolius. Some correlation could exist between antioxidant activity and antiyeast activity against yeasts in the species Ceanothus coeruleus, Schinus molle, Colubrina greggii and Cordia boissieri.
Salazar-Aranda, Ricardo; Pérez-López, Luis Alejandro; López-Arroyo, Joel; Alanís-Garza, Blanca Alicia; Waksman de Torres, Noemí
Traditional medicine has a key role in health care worldwide. Obtaining scientific information about the efficacy and safety of the plants from our region is one of the goals of our research group. In this report, 17 plants were selected and collected in different localities from northeast Mexico. The dried plants were separated into leaves, flowers, fruit, stems, roots and bark. Each part was extracted with methanol, and 39 crude extracts were prepared. The extracts were tested for their antimicrobial activity using three Gram-negative bacterial strains (Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii), three Gram-positive bacterial strains (Enterococcus faecalis and two Staphylococcus aureus strains), and seven clinically isolated yeasts (Candida albicans, C. krusei, C. tropicalis, C. parapsilosis and C. glabrata); their antioxidant activity was tested using a DPPH free radical assay. No activity against Gram-negative bacteria was observed with any extract up to the maximum concentration tested, 1000 μg ml−1. We report here for the first time activity of Ceanothus coeruleus against S. aureus (flowers, minimal inhibitory concentration (MIC) 125 μg ml−1), C. glabrata (MICs 31.25 μg ml−1) and C. parapsilosis (MICs between 31.25 and 125 μg ml−1); Chrysanctinia mexicana against C. glabrata (MICs 31.25 μg ml−1); Colubrina greggii against E. faecalis (MICs 250 μg ml−1) and Cordia boissieri against C. glabrata (MIC 125 μg ml−1). Furthermore, this is the first report about antioxidant activity of extracts from Ceanothus coeruleus, Chrysanctinia mexicana, Colubrina greggii and Cyperus alternifolius. Some correlation could exist between antioxidant activity and antiyeast activity against yeasts in the species Ceanothus coeruleus, Schinus molle, Colubrina greggii and Cordia boissieri. PMID:19770266
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
Plath, Martin; Hermann, Bernd; Schröder, Christiane; Riesch, Rüdiger; Tobler, Michael; García de León, Francisco J; Schlupp, Ingo; Tiedemann, Ralph
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
Background Sporotrichosis is a chronic subcutaneous mycosis of humans and animals, which is typically acquired by traumatic inoculation of plant material contaminated with Sporothrix propagules, or via animals, mainly felines. Sporothrix infections notably occur in outbreaks, with large epidemics currently taking place in southeastern Brazil and northeastern China. Pathogenic species include Sporothrix brasiliensis, Sporothrix schenckii s. str., Sporothrix globosa, and Sporothrix luriei, which exhibit differing geographical distribution, virulence, and resistance to antifungals. The phylogenetically remote species Sporothrix mexicana also shows a mild pathogenic potential. Methods We assessed a genetically diverse panel of 68 strains. Susceptibility profiles of medically important Sporothrix species were evaluated by measuring the MICs and MFCs for amphotericin B (AMB), fluconazole (FLC), itraconazole (ITC), voriconazole (VRC), posaconazole (PCZ), flucytosine (5FC), and caspofungin (CAS). Haplotype networks were constructed to reveal interspecific divergences within clinical Sporothrix species to evaluate genetically deviant isolates. Results ITC and PCZ were moderately effective against S. brasiliensis (MIC90 = 2 and 2 μg/mL, respectively) and S. schenckii (MIC90 = 4 and 2 μg/mL, respectively). PCZ also showed low MICs against the rare species S. mexicana. 5FC, CAS, and FLC showed no antifungal activity against any Sporothrix species. The minimum fungicidal concentration ranged from 2 to >16 μg/mL for AMB against S. brasiliensis and S. schenckii, while the MFC90 was >16 μg/mL for ITC, VRC, and PCZ. Conclusion Sporothrix species in general showed high degrees of resistance against antifungals. Evaluating a genetically diverse panel of strains revealed evidence of multidrug resistant phenotypes, underlining the need for molecular identification of etiologic agents to predict therapeutic outcome. PMID:24755107
Schmitter-Soto, Juan J; Ruiz-Cauich, Lissie E; Herrera, Roberto L; González-Solís, David
An Index of Biotic Integrity (IBI) is proposed, based on the fish communities and populations in streams of the Hondo River basin, Mexico-Belize. Freshwater environments in this area are threatened by exotic fishes, eutrophication, and pesticide pollution, among other problems. This IBI should allow to identify the most vulnerable sites and eventually guide rehabilitation efforts. Data on composition, structure, and function of fish communities were evaluated. Twenty-three sites in the Mexican part of the basin were explored; a stratified sample of 13 sites was used to design the IBI, and the rest were used to test and refine the index. Thirty-four candidate indicator metrics were scanned for their correlation with an index of water and habitat quality (IWHQ), as well as for the possible influence of stream width and altitude or distance to the Hondo River mainstem. Twelve variables were selected to constitute the IBI: relative abundances of Astyanax aeneus, 'Cichlasoma' urophthalmus, Poecilia mexicana, Poecilia sp. (a new species, probably endemic to the upper Hondo River basin), Xiphophorus hellerii, and X. maculatus; relative abundances of bentholimnetic, herbivore, and sensitive species; percentage of native and tolerant species; and Pielou's evenness index. Most of the sites have a low-medium quality and integrity, showing impact due to partial channelization or to suboptimal water quality, reflected in scarcity or absence of sensitive species, frequent excess of tolerant species, occasional presence of exotics, dominance of herbivores (perhaps due to proliferation of filamentous algae), or dominance of the opportunistic species P. mexicana. The streams with better water and habitat quality are those farthest away from the river mainstem, probably because of lower human population and economical production. Copyright © 2010 Elsevier B.V. All rights reserved.
Four new species of the previously monotypic genus Narberdia Burke are described. All of them are intimately associated with plants of the genus Bernardia (Euphorbiaceae). Narberdia cervantae Soto-Hernández, new species (México, Jalisco on Bernardia spongiosa McVaugh), N. sarukhani Soto-Hernández, new species (México, Veracruz and Costa Rica on B. mexicana (Hook. & Arn.) Müll. Arg. and B. nicaraguensis Standl. & L.O. Williams), N. dugesi Soto-Hernández (México, Querétaro and Michoacán on B. mexicana and B. albida Lundell), and N. ramuvei Soto-Hernández, new species (México, Durango, Jalisco and Puebla on B. changii A. Cerv. & Flores Olv., B. rzedowskii A. Cerv. & Flores Olv. and B. valdesii A. Cerv. & Flores Olv.). Use of more than one species of plant as a host by one species of weevil is a common occurrence in Anthonomini. Sexual dimorphism is evident in the species with the female rostrum more slender and relatively longer than in male, the antennal scape attached near the midpoint of the rostrum in the female and beyond the midpoint in the male, and female with pro- and mesotibia bearing a tooth adjacent to the mucro, this tooth absent in the male. Specimens were collected at elevations from 62 m to 2288 m. The genus, previously only known from the United States of America and extreme northern México is now also known from Costa Rica as well as other areas of México. Narberdia apparently is most closely related to several Anthonomus squamosus species group members, both with similar characters of the body and form of the male median lobe (broad at the apex and strongly narrowed near the apex).
The present document is a brief summary of the performed activities during the 2001 Summer Student Programme at CERN under the Scientific Summer at Foreign Laboratories Program organized by the Particles and Fields Division of the Mexican Physical Society (Sociedad Mexicana de Fisica). In this case, the activities were related with the ALICE Pixel Group of the EP-AIT Division, under the supervision of Jeroen van Hunen, research fellow in this group. First, I give an introduction and overview to the ALICE experiment; followed by a description of wafer probing. A brief summary of the test beam that we had from July 13th to July 25th is given as well.
Jarquín-González, Jani; García-Madrigal, María Del Socorro; Carrera-Parra, Luis Fernando
Forty three species of leptocheliids are known worldwide. In the American region only eight species have been described from the Western Atlantic, while for the Eastern Pacific none have been described, suggesting that the diversity of this family has been severely underestimated in this region. Here we describe the first species of Leptochelia from the Eastern Pacific, Leptochelia mexicana n. sp., which is characterized by the males having a spiniform seta on the second segment of uropodal endopod, a novel feature for the genus. In addition, the first annotated checklist and a taxonomic key with illustrations for Leptochelia species are included. The list includes the type locality, type depository, distribution, habitat and, in some cases, remarks.
Hernando-Almudí, Ernesto; Cerdán-Pascual, Rafael; Vallejo-Bernad, Cristina; Martín-Cuartero, Joaquín; Sánchez-Rubio, María; Casamayor-Franco, Carmen
Intestinal malrotation is a congenital anomaly of the intestinal rotation and fixation, and usually occurs in the neonatal age. Description of a clinical case associated with acute occlusive symptoms. A case of intestinal malrotation is presented in a previously asymptomatic woman of 46 years old with an intestinal obstruction, with radiology and surgical findings showing an absence of intestinal rotation. Intestinal malrotation in adults is often asymptomatic, and is diagnosed as a casual finding during a radiological examination performed for other reasons. Infrequently, it can be diagnosed in adults, associated with an acute abdomen. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.
Rai, M K
A serious leaf-spot disease of Mangifera indica was noted during the last 10 years in Satpura plateau of India. On the basis of characteristic symptoms and cultural characters, the pathogen was identified as Pestalotiopsis mangiferae which is hitherto not reported from Satpura plateau of India. Screening of 17-medicinal plants against the test pathogen revealed 14 antimycotic whereas 3-plants, viz., Argemone mexicana, Caesalpinia bonducella, and Casia fistula acclerated the growth of the pathogen. The maximum activity was shown by Eucalyptus globulus (88%) and Catharanthus roseus (88%) followed by Ocimum sanctum (85.50%), Azadirachta indica (84.66%), Ricinus communis (75%) and Lawsonia inermis (74.33%) while the minimum activity was exhibited by Jatropha curcas (10%).
... following excise, luxury, and transaction taxes: (1) Derechos de Aduana (Customs Duties). (2) Impuesto de... Transactions). (6) Impuesto Sobre el Trafico de Empresas (Business Trade Tax). (7) Impuestos Especiales de...-Products). (9) Impuesto Sobre el Uso de Telefona (Telephone Tax). (10) Impuesto General Sobre la Renta de...
... following excise, luxury, and transaction taxes: (1) Derechos de Aduana (Customs Duties). (2) Impuesto de... Transactions). (6) Impuesto Sobre el Trafico de Empresas (Business Trade Tax). (7) Impuestos Especiales de...-Products). (9) Impuesto Sobre el Uso de Telefona (Telephone Tax). (10) Impuesto General Sobre la Renta de...
...) [SDNTK] 2. DORIA CASTILLO, Danit Dario, c/o INVERSIONES MINERAS H.D. EMPRESA UNIPERSONAL, Caucasia...., Medellin, Colombia; c/o INVERSIONES BUENOS AIRES LTDA., Pereira, Colombia; DOB 28 Apr 1964; POB Bello...., Villavicencio, Colombia; c/o INVERSIONES BUENOS AIRES LTDA., Pereira, Colombia; c/o INVERSIONES Y DISTRIBUCIONES...
Rodriguez Plaza, Evelyn
El proposito de esta investigacion fue identificar los componentes de la preparacion en ciencia que deben recibir los estudiantes del Bachillerato en Artes en Educacion Elemental, Nivel Primario, de acuerdo a los documentos que dirigen la reforma de la educacion cientifica en Puerto Rico. Tambien, se identificaron los componentes de los cursos que forman parte de la preparacion en ciencia de estos estudiantes. Se compararon los componentes de la preparacion en ciencia y los componentes de los cursos para determinar congruencias y discrepancias. Con los datos recopilados se identificaron los componentes de los cursos de una secuencia curricular para la preparacion en ciencia de los candidatos a maestros del nivel elemental primario. La secuencia curricular que se propone en esta investigacion incluye cursos de contenido cientifico y de metodologia en la ensenanza de la ciencia disenados para satisfacer las necesidades de los candidatos. Se recomienda que en los procesos para el diseno, la implantacion y la evaluacion de estos cursos participen profesores de ciencia, profesores de educacion y maestros del nivel elemental primario. Todos los cursos de la secuencia curricular deben tener un enfoque constructivista. Las experiencias educativas que se incluyan en los cursos deben aspirar a desarrollar en los candidatos los atributos de la cultura cientifica y actitudes positivas hacia la ciencia y hacia la ensenanza de esta disciplina. El modelaje por parte de los profesores que ensenen los cursos de la secuencia curricular es fundamental en el desarrollo profesional de los candidatos. Se recomienda que en los cursos de contenido cientifico se estudien los conceptos y los conocimientos cientificos que forman parte del curriculo de Kindergarten a tercer grado de forma integrada y con una profundidad universitaria. Estos cursos deben tener un enfoque interdisciplinario e incluir el estudio de la naturaleza de la ciencia y un componente de laboratorio para desarrollar los
Bramsen, Jesper B.; Pakula, Malgorzata M.; Hansen, Thomas B.; Bus, Claus; Langkjær, Niels; Odadzic, Dalibor; Smicius, Romualdas; Wengel, Suzy L.; Chattopadhyaya, Jyoti; Engels, Joachim W.; Herdewijn, Piet; Wengel, Jesper; Kjems, Jørgen
Small interfering RNAs (siRNAs) are now established as the preferred tool to inhibit gene function in mammalian cells yet trigger unintended gene silencing due to their inherent miRNA-like behavior. Such off-target effects are primarily mediated by the sequence-specific interaction between the siRNA seed regions (position 2–8 of either siRNA strand counting from the 5′-end) and complementary sequences in the 3′UTR of (off-) targets. It was previously shown that chemical modification of siRNAs can reduce off-targeting but only very few modifications have been tested leaving more to be identified. Here we developed a luciferase reporter-based assay suitable to monitor siRNA off-targeting in a high throughput manner using stable cell lines. We investigated the impact of chemically modifying single nucleotide positions within the siRNA seed on siRNA function and off-targeting using 10 different types of chemical modifications, three different target sequences and three siRNA concentrations. We found several differently modified siRNAs to exercise reduced off-targeting yet incorporation of the strongly destabilizing unlocked nucleic acid (UNA) modification into position 7 of the siRNA most potently reduced off-targeting for all tested sequences. Notably, such position-specific destabilization of siRNA–target interactions did not significantly reduce siRNA potency and is therefore well suited for future siRNA designs especially for applications in vivo where siRNA concentrations, expectedly, will be low. PMID:20453030
Teaching Music, 2002
Focuses on the "World's Largest Concerts" listing various songs to be sung by students. Includes teaching tips in the form of quotes from music teachers on aspects of music education, such as teaching rhythm. Includes information on how to access the songs. (CMK)
35 SDVF Single Dimensional Value Function . . . . . . . . . . . . . 44 ENAER Empresa Nacional de Aeronautica... de - viate further from balanced strategies than do individuals” . Kocher and Sutter compared decisions by individuals and groups in beauty...Michaelsen, Watson, and Black de - termined that there have been no studies on individual versus group decision making that provided any significant
Ameca y Juárez, Eric I; Ellis, Edward A; Rodríguez-Luna, Ernesto
Long-term studies quantifying impacts of hurricane activity on growth and trajectory of primate populations are rare. Using a 14-year monitored population of Alouatta palliata mexicana as a study system, we developed a modeling framework to assess the relative contribution of hurricane disturbance and two types of human impacts, habitat loss, and hunting, on quasi-extinction risk. We found that the scenario with the highest level of disturbance generated a 21% increase in quasi-extinction risk by 40 years compared to scenarios of intermediate disturbance, and around 67% increase relative to that found in low disturbance scenarios. We also found that the probability of reaching quasi-extinction due to human disturbance alone was below 1% by 40 years, although such scenarios reduced population size by 70%, whereas the risk of quasi-extinction ranged between 3% and 65% for different scenarios of hurricane severity alone, in absence of human impacts. Our analysis moreover found that the quasi-extinction risk driven by hunting and hurricane disturbance was significantly lower than the quasi-extinction risk posed by human-driven habitat loss and hurricane disturbance. These models suggest that hurricane disturbance has the potential to exceed the risk posed by human impacts, and, in particular, to substantially increase the speed of the extinction vortex driven by habitat loss relative to that driven by hunting. Early mitigation of habitat loss constituted the best method for reducing quasi-extinction risk: the earlier habitat loss is halted, the less vulnerable the population becomes to hurricane disturbance. By using a well-studied population of A. p. mexicana, we help understand the demographic impacts that extreme environmental disturbance can trigger on isolated populations of taxa already endangered in other systems where long-term demographic data are not available. For those experiencing heavy anthropogenic pressure and lacking sufficiently evolved coping
Denise, Hubert; Poot, Jacqueline; Jiménez, Maribel; Ambit, Audrey; Herrmann, Daland C; Vermeulen, Arno N; Coombs, Graham H; Mottram, Jeremy C
Visceral leishmaniasis caused by members of the Leishmania donovani complex is often fatal in the absence of treatment. Research has been hampered by the lack of good laboratory models and tools for genetic manipulation. In this study, we have characterised a L. infantum line (JPCM5) that was isolated from a naturally infected dog and then cloned. We found that JPCM5 has attributes that make it an excellent laboratory model; different stages of the parasite life cycle can be studied in vitro, it is accessible to genetic manipulation and it has retained its virulence. Furthermore, the L. infantum JPCM5 genome has now been fully sequenced. We have further focused our studies on LiCPA, the L. infantum homologue to L. mexicana cysteine peptidase CPA. LiCPA was found to share a high percentage of amino acid identity with CPA proteins of other Leishmania species. Two independent LiCPA-deficient promastigote clones (DeltaLicpa) were generated and their phenotype characterised. In contrast to L. mexicana CPA-deficient mutants, both clones of DeltaLicpa were found to have significantly reduced virulence in vitro and in vivo. Re-expression of just one LiCPA allele (giving DeltaLicpa::CPA) was sufficient to complement the reduced infectivity of both DeltaLicpa mutants for human macrophages, which confirms the importance of LiCPA for L. infantum virulence. In contrast, in vivo experiments did not show any virulence recovery of the re-expressor clone DeltaLicpaC1::CPA compared with the CPA-deficient mutant DeltaLicpaC1. The data suggest that CPA is not essential for replication of L. infantum promastigotes, but is important for the host-parasite interaction. Further studies will be necessary to elucidate the precise roles that LiCPA plays and why the re-expression of LiCPA in the DeltaLicpa mutants complemented the gene deletion phenotype only in in vitro and not in in vivo infection of hamsters.
Handoo, Zafar A.; Carta, Lynn K.; Skantar, Andrea M.; Chitwood, David J.
A new species of cyst nematode, Globodera ellingtonae, is described from soil collected from a field in Oregon. Second-stage juveniles (J2) of the species are characterized by body length of 365-515 μm, stylet length of 19-22.5 μm, basal knobs rounded posteriorly and pointed anteriorly, tail 39-55 μm, hyaline tail terminus 20-32.5 μm, and tail tapering uniformly but abruptly narrowing and constricted near the posterior third of the hyaline portion, ending with a peg-like, finely rounded to pointed terminus. Cysts are spherical to sub-spherical, dark to light brown and circumfenestrate and cyst wall pattern is ridge-like with heavy punctations. Males have a stylet length of 21-25 μm and spicule length of 30-37 μm with a pointed thorn-like tip. Females have a stylet length of 20-22.5 μm, one head annule and labial disc, heavy punctations on the cuticle, and short vulval slit 7.5-8 μm long. Morphologically this new, round-cyst species differs from the related species G. pallida, G. rostochiensis, G. tabacum complex and G. mexicana by its distinctive J2 tail, and by one or another of the following: shorter mean stylet length in J2, females and males; number of refractive bodies in the hyaline tail terminus of J2; cyst morphology including Granek’s ratio; number of cuticular ridges between the anus and vulva; and in the shape and length of spicules in males. Its relationship to these closely related species are discussed. Based upon analysis of ribosomal internal transcribed spacer (ITS) sequences, G. ellingtonae n. sp. is distinct from G. pallida, G. rostochiensis, G. tabacum and G. mexicana. Bayesian and Maximum Parsimony analysis of cloned ITS rRNA gene sequences indicated three clades, with intraspecific variability as high as 2.8%. In silico analysis revealed ITS restriction fragment length polymorphisms for enzymes Bsh 1236I, Hinf I, and Rsa I that overlap patterns for other Globodera species. PMID:23483076
Rodrigues, Anderson Messias; de Hoog, G. Sybren; de Camargo, Zoilo Pires
Background Sporotrichosis is a chronic (sub)cutaneous infection caused by thermodimorphic fungi in the order, Ophiostomatales. These fungi are characterized by major differences in routes of transmission, host predilections, species virulence, and susceptibilities to antifungals. Sporothrix species emerge in the form of outbreaks. Large zoonoses and sapronoses are ongoing in Brazil and China, respectively. Current diagnostic methods based on morphology and physiology are inaccurate due to closely related phenotypes with overlapping components between pathogenic and non-pathogenic Sporothrix. There is a critical need for new diagnostic tools that are specific, sensitive, and cost-effective. Methodology We developed a panel of novel markers, based on calmodulin (CAL) gene sequences, for the large-scale diagnosis and epidemiology of clinically relevant members of the Sporothrix genus, and its relative, Ophiostoma. We identified specific PCR-based markers for S. brasiliensis, S. schenckii, S. globosa, S. mexicana, S. pallida, and O. stenoceras. We employed a murine model of disseminated sporotrichosis to optimize a PCR assay for detecting Sporothrix in clinical specimens. Results Primer-BLAST searches revealed candidate sequences that were conserved within a single species. Species-specific primers showed no significant homology with human, mouse, or microorganisms outside the Sporothrix genus. The detection limit was 10–100 fg of DNA in a single round of PCR for identifying S. brasiliensis, S. schenckii, S. globosa, S. mexicana, and S. pallida. A simple, direct PCR assay, with conidia as a source of DNA, was effective for rapid, low-cost genotyping. Samples from a murine model of disseminated sporotrichosis confirmed the feasibility of detecting S. brasiliensis and S. schenckii DNA in spleen, liver, lungs, heart, brain, kidney, tail, and feces of infected animals. Conclusions This PCR-based method could successfully detect and identify a single species in samples
Handoo, Zafar A; Carta, Lynn K; Skantar, Andrea M; Chitwood, David J
A new species of cyst nematode, Globodera ellingtonae, is described from soil collected from a field in Oregon. Second-stage juveniles (J2) of the species are characterized by body length of 365-515 μm, stylet length of 19-22.5 μm, basal knobs rounded posteriorly and pointed anteriorly, tail 39-55 μm, hyaline tail terminus 20-32.5 μm, and tail tapering uniformly but abruptly narrowing and constricted near the posterior third of the hyaline portion, ending with a peg-like, finely rounded to pointed terminus. Cysts are spherical to sub-spherical, dark to light brown and circumfenestrate and cyst wall pattern is ridge-like with heavy punctations. Males have a stylet length of 21-25 μm and spicule length of 30-37 μm with a pointed thorn-like tip. Females have a stylet length of 20-22.5 μm, one head annule and labial disc, heavy punctations on the cuticle, and short vulval slit 7.5-8 μm long. Morphologically this new, round-cyst species differs from the related species G. pallida, G. rostochiensis, G. tabacum complex and G. mexicana by its distinctive J2 tail, and by one or another of the following: shorter mean stylet length in J2, females and males; number of refractive bodies in the hyaline tail terminus of J2; cyst morphology including Granek's ratio; number of cuticular ridges between the anus and vulva; and in the shape and length of spicules in males. Its relationship to these closely related species are discussed. Based upon analysis of ribosomal internal transcribed spacer (ITS) sequences, G. ellingtonae n. sp. is distinct from G. pallida, G. rostochiensis, G. tabacum and G. mexicana. Bayesian and Maximum Parsimony analysis of cloned ITS rRNA gene sequences indicated three clades, with intraspecific variability as high as 2.8%. In silico analysis revealed ITS restriction fragment length polymorphisms for enzymes Bsh 1236I, Hinf I, and Rsa I that overlap patterns for other Globodera species.
Gugsa, Likyelesh; Sarial, Ashok K; Lörz, Horst; Kumlehn, Jochen
Tef [Eragrostis tef (Zucc.) Trotter] is the most important cereal in Ethiopia. In its wild relative E. mexicana, regeneration of six green plants resulted from culture of 121 non-pollinated immature pistils. In the allotetraploid crop species tef, however, only callus and root formation was obtained by this method. By contrast, immature spikelets and panicle segments of E. tef proved amenable to gynogenic plant regeneration. Upon step-wise optimization of the protocol, efficient plant formation was achieved in all three cultivars tested. In cv. DZ-01-196, culture of 1305 immature spikelets resulted in formation of 159 green plants. Flow cytometric analysis revealed (di)haploid, triploid, tetraploid and octoploid regenerants, from which the vast majority was tetraploid. Tef-breeding programs will likely benefit substantially from efficient generation of true-breeding plants.
Leicht, S.A.; Silander, J.A.; Greenwood, K.
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.
Contreras-Marín, Misael; Sandoval-Rodríguez, Jorge Issac; García-Ramírez, Raúl; Morales-Yépez, Héctor Adolfo
Animal bites are a major public health problem, it is estimated that 2% of the population is bitten each year. Most bites are by dogs and the risk factors include young children, men, certain breeds of dogs and untrained dogs. The risk of infection after bites differs between animal species and depends on the animal teeth and oral flora. Animal bites are still a major cause of morbidity in patients of all ages and have caused several preventable childhood deaths. These wounds often become infected. If the wound requires it, early surgical evaluation must be performed. The use of antibiotics is only recommended for high risk bite wounds. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.
Brundage, Adrienne; Bros, Shannon; Honda, Jeffrey Y
Seasonal and habitat calliphorid abundance and distribution were examined weekly for two years (2001-2003) in Santa Clara County, California, using sentinel traps baited with bovine liver. Of the 34,389 flies examined in three defined habitats (rural, urban, and riparian), 38% of the total catch represented Compsomyiops callipes (Bigot) and 23% represented Phormia regina (Meigen). Other flies collected in this survey included Calliphora vomitoria (Linnaeus), Calliphora latifrons (Hough), Lucilia sericata (Meigen), Lucilia cuprina (Wiedemann), and Lucilia mexicana (Macquart), which is a new record for the area. Multivariate MANOVA and ANOVA (P ≤ 0.05) analysis indicate significant seasonal habitat preference for all fly species examined. This information may be used to identify potentially forensically impo rtant fly species within Santa Clara County, California. Published by Elsevier Ireland Ltd.
de Fátima O. Saraiva, Maria; Amador, Cláudio B.; Kemper, Érico; Goulart, Paulo; Muller, Angela
We present a very simple concrete model to demonstrate the concept of phases of an illuminated body. The main objective of our model is to help the understanding of the Moon phases as viewed from the perspective of an observer on Earth. The material allows the visualization of two important effects: (1st) even though all the time half Moon is illuminated by the Sun, we see different fractions of the illuminated Moon surface, depending on our angle of sight; (2nd) the orientation of the convex part of the Moon in the crescent and waning phases on the sky also depends on our perspective from Earth. The use of a closed box allows one to see the contrast among the different phases with no need of a dark room. We also present a text on the Moon phases, emphasizing the dependence of the aspect of the bright part on the angle of sight. En este trabajo proponemos la construcción de material didáctico de bajo costo para demostración del concepto de fases de un cuerpo iluminado. El principal objetivo de nuestro material es facilitar la comprensión de las fases de la Luna desde la perspectiva de un observador en la Tierra. El material ayuda la visualización de dos efectos importantes: (1º) a pesar de tener siempre la mitad de la Luna (representada por una bolita de espuma plástica o de ping-pong), iluminada por el Sol ( representado por una fuente de luz natural o artificial), vemos diferentes fracciones de su superficie iluminada, dependiendo del ángulo por el cual la vemos; (2º) la orientación del borde convexo de la Luna en las fases Creciente y Menguante también depende de la perspectiva por la cual la miramos desde la Tierra. El uso de una caja cerrada permite observar el contraste entre las diferentes fases sin necesidad de estar en un recinto oscuro. Presentamos también un texto explicativo sobre las fases de la Luna, enfatizando la dependencia de la apariencia de la parte iluminada con el ángulo de visión. Neste trabalho propomos a construção de
The directory contains worldwide information Administrations et Services Aeroautiques. Designadores de Empresas Explotadoras about aviation/aerospace...ADVISORY GROUP FOR AEROSPACE RESEARCH AND DEVELOPMENT (ORGANISATION DU TRAITE DE L’ATLANTIQUE NORD) AGARD Report No.7 18 * GUIDES TO AEROSPACE RESEARCH...and transport containing also The Tithe and Keyword Index includes titles of all establishments listed in this highly professional photographs received
The TOR gene (TOxic nucleoside Resistance gene) was mapped to a 2.3 kb fragment on the amplified DNA from tubercidin resistant Leishmania (TUB). This DNA fragment conferred upon wild type cells resistance to tubercidin, inosine dialdehyde, formycin A and B and allopurinol riboside and a reduced ability to accumulate purine nucleobases and nucleosides. These properties were characteristic of the parental TUB cells which carried the intact amplified DNA and have been hypothesized to be caused by a reduction in the activity of the multiple purine transporters within this organism. The TOR gene was found to be partially homologous to the rodent and human Oct-6/SCIP/Tst-1 gene. It lacked, however, the POU specific domain of this class of transcription factors and contained only the first two helices of the POU homeodomain. This truncated homeodomain was not required to confer resistance upon wild type cells to toxic nucleosides, suggesting that TOR was not a repressor with independent DNA binding capability.
Grant, Karen M.; Dunion, Morag H.; Yardley, Vanessa; Skaltsounis, Alexios-Leandros; Marko, Doris; Eisenbrand, Gerhard; Croft, Simon L.; Meijer, Laurent; Mottram, Jeremy C.
The CRK3 cyclin-dependent kinase of Leishmania has been shown by genetic manipulation of the parasite to be essential for proliferation. We present data which demonstrate that chemical inhibition of CRK3 impairs the parasite's viability within macrophages, thus further validating CRK3 as a potential drug target. A microtiter plate-based histone H1 kinase assay was developed to screen CRK3 against a chemical library enriched for protein kinase inhibitors. Twenty-seven potent CRK3 inhibitors were discovered and screened against Leishmania donovani amastigotes in vitro. Sixteen of the CRK3 inhibitors displayed antileishmanial activity, with a 50% effective dose (ED50) of less than 10 μM. These compounds fell into four chemical classes: the 2,6,9-trisubstituted purines, including the C-2-alkynylated purines; the indirubins; the paullones; and derivatives of the nonspecific kinase inhibitor staurosporine. The paullones and staurosporine derivatives were toxic to macrophages. The 2,6,9-trisubstituted purines inhibited CRK3 in vitro, with 50% inhibitory concentrations ranging from high nanomolar to low micromolar concentrations. The most potent inhibitors of CRK3 (compounds 98/516 and 97/344) belonged to the indirubin class; the 50% inhibitory concentrations for these inhibitors were 16 and 47 nM, respectively, and the ED50s for these inhibitors were 5.8 and 7.6 μM, respectively. In culture, the indirubins caused growth arrest, a change in DNA content, and aberrant cell types, all consistent with the intracellular inhibition of a cyclin-dependent kinase and disruption of cell cycle control. Thus, use of chemical inhibitors supports genetic studies to confirm CRK3 as a validated drug target in Leishmania and provides pharmacophores for further drug development. PMID:15273118
Vargas, Edward D.; Winston, Nadia C.; Garcia, John A.; Sanchez, Gabriel R.
Discrimination based on one’s racial or ethnic background is one of the oldest and most perverse practices in the United States. While much of this research has relied on self-reported racial categories, a growing body of research is attempting to measure race through socially-assigned race. Socially-assigned or ascribed race measures how individuals feel they are classified by other people. This paper draws on the socially assigned race literature and explores the impact of socially assigned race on experiences with discrimination using a 2011 nationally representative sample of Latina/os (n=1,200). While much of the current research on Latina/os has been focused on the aggregation across national origin group members, this paper marks a deviation by using socially-assigned race and national origin to understand how being ascribed as Mexican is associated with experiences of discrimination. We find evidence that being ascribed as Mexican increases the likelihood of experiencing discrimination relative to being ascribed as White or Latina/o. Furthermore, we find that being miss-classified as Mexican (ascribed as Mexican, but not of Mexican origin) is associated with a higher likelihood of experiencing discrimination compared to being ascribed as white, ascribed as Latina/o, and correctly ascribed as Mexican. We provide evidence that socially assigned race is a valuable complement to self-identified race/ethnicity for scholars interested in assessing the impact of race/ethnicity on a wide range of outcomes. PMID:27709119
Ricaurte, Orlando; Neita, Karina; Valero, Danyela; Ortega-Rojas, Jenny; Arboleda-Bustos, Carlos E; Zubieta, Camilo; Penagos, José; Arboleda, Gonzalo
Introducción. Los gliomas son los tumores primarios más comunes del sistema nervioso central y se clasifican de I a IV según su grado de malignidad. En recientes investigaciones se ha encontrado que su aparición está relacionada con mutaciones en el exón 4 de los genes que codifican las deshidrogenasas de isocitrato 1 y 2 (IDH1: codón 132; IDH2: codón 172).Objetivo. Determinar la frecuencia de mutaciones en los genes IDH1 e IDH2 en una muestra de gliomas de pacientes colombianos.Materiales y métodos. La extracción de ADN se hizo a partir de tejido tumoral. El exón 4 de los genes IDH1 e IDH2 se amplificó mediante PCR utilizando iniciadores específicos y, posteriormente, se secuenciaron. Para la determinación de las mutaciones, se emplearon los programas 4Peaks y MAFFT.Resultados. Se determinó la presencia de mutaciones en el gen IDH1 en el 34 % de las muestras, con predominio de la mutación no sinónima R132H. En el 7,5 % de los casos se detectaron mutaciones en el gen IDH2, principalmente las mutaciones no sinónimas R172K y R172W.Conclusiones. La frecuencia de mutaciones en los genes IDH1 e IDH2 en la muestra fue similar a la reportada en otros estudios. El análisis de estas mutaciones puede ser importante como factor pronóstico y para su uso como potenciales blancos terapéuticos en gliomas.
González-León, Carlos M.; Barajas, Arturo Martin
The eight papers presented in this special issue are contributions that were received following the Fourth Meeting on the Geology of Northwestern Mexico and Adjacent Areas that took place from March 6- 8, 2000, in Hermosillo, México. The meeting was organized by the Estación Regional del Noroeste, Instituto de Geología, Universidad Nacional Autónoma de México; Departamento de Geología, Universidad de Sonora; Departamento de Geología, Centro de Investigación Científica y Estudios Superiores de Ensenada; Departamento de Geociencias, Centro de Estudios Superiores del Estado de Sonora; Distrito Sonora, Asociación de Ingenieros de Minas, Metalurgistas y Geólogos de México and Sociedad Geológica Mexicana. The manuscripts present new result that constitute recent advances to our understanding of the geology of southwestern North America.
Pérez-Calatayud, Ángel Augusto; Guillén-Vidaña, Ariadna; Fraire-Félix, Irving Santiago; Anica-Malagón, Eduardo Daniel; Briones Garduño, Jesús Carlos; Carrillo-Esper, Raúl
Metabolic changes of glucose in critically ill patients increase morbidity and mortality. The appropriate level of blood glucose has not been established so far and should be adjusted for different populations. However concepts such as glucose variability and relative hypoglycemia of critically ill patients are concepts that are changing management methods and achieving closer monitoring. The purpose of this review is to present new data about the management and metabolic control of patients in critical areas. Currently glucose can no longer be regarded as an innocent element in critical patients; both hyperglycemia and hypoglycemia increase morbidity and mortality of patients. Protocols and better instruments for continuous measurement are necessary to achieve the metabolic control of our patients. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.
Hernández-Baz, F; Coates, R; Teston, J A; González, J M
A revision of the bibliography, as well as an analysis on the data from the specimen labels of Scena propylea (Druce) (Erebidae: Arctiinae: Euchromiina) deposited in different scientific collections, was carried out and included information from 1894 to 2010. Its geographical distribution is restricted to the Trans-Mexican Volcanic Belt which determines this species as endemic. Data are provided on the biogeography, ecology and biology for this species. Its food plant is Thenardia floribunda (Apocynaceae) which is also endemic to Mexico. From this analysis, we propose the inclusion of both species in the document known as the Norma Oficial Mexicana 059 which encompasses the environmental protection of wild flora and fauna species native to Mexico and their risk categories, as well as the specifications for their inclusion, exclusion or change and a list of all species at risk.
Noyola-Villalobos, Héctor Faustino; Loera-Torres, Marco Antonio; Jiménez-Chavarría, Enrique; Núñez-Cantú, Olliver; García-Núñez, Luis Manuel; Arcaute-Velázquez, Fernando Federico
Hepatic trauma is a common cause for admissions in the Emergency Room. Currently, non-surgical management is the standard treatment in haemodynamically stable patients with a success rate of around 85 to 98%. This haemodynamic stability is the most important factor in selecting the appropriate patient. Adjuncts in non-surgical management are angioembolisation, image-guided drainage and endoscopic retrograde cholangiopancreatography. Failure in non-surgical management is relatively rare but potentially fatal, and needs to be recognised and aggressively treated as early as possible. The main cause of failure in non-surgical management is persistent haemorrhage. The aim of this paper is to describe current evidence and guidelines that support non-surgical management of liver injuries in blunt trauma. Copyright © 2016 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.
Kato, Hirotomo; Cáceres, Abraham G; Gomez, Eduardo A; Mimori, Tatsuyuki; Uezato, Hiroshi; Hashiguchi, Yoshihisa
Haplotype and gene network analyses were performed on mitochondrial cytochrome oxidase I and cytochrome b gene sequences of Lutzomyia (Lu.) ayacuchensis populations from Andean areas of Ecuador and southern Peru where the sand fly species transmit Leishmania (Leishmania) mexicana and Leishmania (Viannia) peruviana, respectively, and populations from the northern Peruvian Andes, for which transmission of Leishmania by Lu. ayacuchensis has not been reported. The haplotype analyses showed higher intrapopulation genetic divergence in northern Peruvian Andes populations and less divergence in the southern Peru and Ecuador populations, suggesting that a population bottleneck occurred in the latter populations, but not in former ones. Importantly, both haplotype and phylogenetic analyses showed that populations from Ecuador consisted of clearly distinct clusters from southern Peru, and the two populations were separated from those of northern Peru. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.
Oca-Aguilar, Ana Celia Montes DE; Mikery-Pacheco, Oscar; Castillo, Alfredo; Rebollar-Téllez, Eduardo A; Piermarini, Peter M; Ibáñez-Bernal, Sergio
The sand fly Lutzomyia cruciata has been associated with the transmission of Leishmania mexicana to humans in Mexico. This species has a wide distribution in Mexico occupying different microhabitats and environments. In this work comparisons of the egg exochorion of Lu. cruciata from different physiographic areas are presented. Study sites are from different states of southern Mexico. Exochorion analysis was carried out using scanning electron microscopy (SEM). Results show differences in the exochorionic pattern among samples from Veracruz (AVER), Yucatán (HOYU) and Chiapas (TACH). The morphotype "Chiapas" has a polygonal crest pattern, the morphotype "Veracruz" shows parallel and longitudinal crests with some or few connections, and the morphotype "Yucatán" has weak connections between crest ridges. These morphological differences could be the result of local adaptations or evidence of divergence within the nominal unit Lutzomyia cruciata.
Falcón-Ordaz, Jorge; Guzmán-Cornejo, Carmen; García-Prieto, Luis; Gardner, Scott Lyell
On the basis of the revision of the type material of Anoplostrongylus delicatus Schwartz, 1927, and new specimens collected from Tadarida brasiliensis mexicana (Saussure, 1860) in 4 arid localities from Mexico, we describe a new genus (Tadaridanema n. gen.), to which A. delicatus is transferred (as Tadaridanema delicatus (Schwartz, 1927) n. gen., n. comb.). This new genus differs from all other genera included in Anoplostrongylinae by having ray 2 larger than ray 3. In addition, T. delicatus can be differentiated from the type species of Anoplostrongylus (Anoplostrongylus paradoxus (Travassos, 1918)) because it possess vestibular branches equal in length, cephalic inflation divided into 2 regions, and synlophe with many small ridges at the midbody level, whereas in T. delicatus, vestibular branches are equal in size, cephalic inflation is simple in structure, and the synlophe has only 2 well-developed dorsal cuticular ridges.
Stoopen-Margain, Enrique; Valanci-Aroesty, Sofía; Castañeda-Martínez, Leopoldo; Baquera-Heredia, Javier; Sainz-Hernández, Juan Carlos
Primary hyperparathyroidism is a disease characterised by the autonomous production of parathyroid hormone. The most common cause is an adenoma, followed by hyperplasia, and rarely carcinoma. Three cases are presented. The first case is associated with a brown tumour that was diagnosed as hyperplasia after study and surgery. The second case was related to pathological fractures, and a lower right adenoma 236 times bigger than a normal parathyroid was excised. The last case presented with abdominal pain and heartburn. Histopathology reported a carcinoma, which was removed using surgery en bloc. All patients have improved. Hyperparathyroidism symptoms are very difficult to identify and diagnose, thus a detailed and broad approach is needed when hyperparathyroidism is suspected. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.
Ortiz, Diana; Forquer, Isaac; Boitz, Jan; Soysa, Radika; Elya, Carolyn; Fulwiler, Audrey; Nilsen, Aaron; Polley, Tamsen; Riscoe, Michael K; Ullman, Buddy; Landfear, Scott M
Endochin-like quinolones (ELQs) are potent and specific inhibitors of cytochrome bc1 from Plasmodium falciparum and Toxoplasma gondii and show promise for novel antiparasitic drug development. To determine whether the mitochondrial electron transport chain of Leishmania parasites could be targeted similarly for drug development, we investigated the activity of 134 structurally diverse ELQs. A cohort of ELQs was selectively toxic to amastigotes of Leishmania mexicana and L. donovani, with 50% inhibitory concentrations (IC50s) in the low micromolar range, but the structurally similar hydroxynaphthoquinone buparvaquone was by far the most potent inhibitor of electron transport, ATP production, and intracellular amastigote growth. Cytochrome bc1 is thus a promising target for novel antileishmanial drugs, and further improvements on the buparvaquone scaffold are warranted for development of enhanced therapeutics. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
Miranda, Aracelis; Samudio, Franklyn; González, Kadir; Saldaña, Azael; Brandão, Adeilton; Calzada, Jose E.
A precise identification of Leishmania species involved in human infections has epidemiological and clinical importance. Herein, we describe a preliminary validation of a restriction fragment length polymorphism assay, based on the calmodulin intergenic spacer region, as a tool for detecting and typing Leishmania species. After calmodulin amplification, the enzyme HaeIII yielded a clear distinction between reference strains of Leishmania mexicana, Leishmania amazonensis, Leishmania infantum, Leishmania lainsoni, and the rest of the Viannia reference species analyzed. The closely related Viannia species: Leishmania braziliensis, Leishmania panamensis, and Leishmania guyanensis, are separated in a subsequent digestion step with different restriction enzymes. We have developed a more accessible molecular protocol for Leishmania identification/typing based on the exploitation of part of the calmodulin gene. This methodology has the potential to become an additional tool for Leishmania species characterization and taxonomy. PMID:27352873
Oliveira, Manoel Marques Evangelista; Maifrede, Simone Bravim; Ribeiro, Mariceli Araújo; Zancope-Oliveira, Rosely Maria
Sporotrichosis is a widespread subcutaneous mycosis caused by the dimorphic fungi now known as the Sporothrix schenckii complex. This complex is comprised of at least six species, including Sporothrix albicans, Sporothrix brasiliensis, Sporothrix globosa, Sporothrix luriei, Sporothrix mexicana and S. schenckii. Cases of sporotrichosis have significantly increased in Brazil over the past decade, especially in the state of Rio de Janeiro (RJ), where an epidemic among cat owners has been observed. The zoonotic transmission from cats to humans suggests a common source of infection and indicates that animals can act as vectors. We performed a molecular characterisation of samples collected during the first outbreak of familial sporotrichosis caused by S. brasiliensis in the state of Espírito Santo, Brazil. These results represent the first description of such an outbreak outside the endemic area of zoonotic sporotrichosis in RJ. PMID:24141957
Oliveira, Manoel Marques Evangelista; Maifrede, Simone Bravim; Ribeiro, Mariceli Araújo; Zancope-Oliveira, Rosely Maria
Sporotrichosis is a widespread subcutaneous mycosis caused by the dimorphic fungi now known as the Sporothrix schenckii complex. This complex is comprised of at least six species, including Sporothrix albicans, Sporothrix brasiliensis, Sporothrix globosa, Sporothrix luriei, Sporothrix mexicana and S. schenckii. Cases of sporotrichosis have significantly increased in Brazil over the past decade, especially in the state of Rio de Janeiro (RJ), where an epidemic among cat owners has been observed. The zoonotic transmission from cats to humans suggests a common source of infection and indicates that animals can act as vectors. We performed a molecular characterisation of samples collected during the first outbreak of familial sporotrichosis caused by S. brasiliensis in the state of Espírito Santo, Brazil. These results represent the first description of such an outbreak outside the endemic area of zoonotic sporotrichosis in RJ.
Tobler, Michael; Schlupp, Ingo; García de León, Francisco J.; Glaubrecht, Matthias; Plath, Martin
Living in extreme habitats typically requires costly adaptations of any organism tolerating these conditions, but very little is known about potential benefits that trade off these costs. We suggest that extreme habitats may function as refuge from parasite infections, since parasites can become locally extinct either directly, through selection by an extreme environmental parameter on free-living parasite stages, or indirectly, through selection on other host species involved in its life cycle. We tested this hypothesis in a small freshwater fish, the Atlantic molly ( Poecilia mexicana) that inhabits normal freshwaters as well as extreme habitats containing high concentrations of toxic hydrogen sulfide. Populations from such extreme habitats are significantly less parasitized by the trematode Uvulifer sp. than a population from a non-sulfidic habitat. We suggest that reduced parasite prevalence may be a benefit of living in sulfidic habitats.
visiting seminars at American University in Cairo and Instituto de Empresas in Madrid. His Air Force contracting experience includes F-22 Fighter, C...17 Cargo Transport , and serving as director of Joint Contracting Command-North, Kirkuk, Iraq. At the Pentagon, Dr. Reed was responsible for...Department of Transportation –Federal Aviation Administration. The model uses historical program data to derive recommended staffing levels for major
Management,” Harvard Business Review, Sept-Oct/83. 40 “Boletin Trimestral Empresas de Transporte Aereo No...to signify rotary-wing aircraft capable of transporting more than 4 tons of payload. 8 “Secretaria del Senado – Republica de Colombia” (Secretary of... de Aviacion controls the civil non-regular air transportation in Colombia. According to Aerocivil statistics, the company’s helicopters moved 57.58
Empresa Brasileira de Aeronautica, S.A. (Embraer) has plans to begin production of the KC-390...the reserves, be de - activated, and be unable to return to his previous branch, thereby eliminating his potential bias. This further increases...tradi- tional and one nuclear submarine in an agree- ment with France. A new facility for the subma- rines will be built in Itaguai, Rio de
Buchalski, Michael R; Sacks, Benjamin N; Gille, Daphne A; Penedo, Maria Cecilia T; Ernest, Holly B; Morrison, Scott A; Boyce, Walter M
de las ovejas del desierto ( Ovis canadensis subespecies) contemporáneas son ambiguos. Para dilucidar esta incertidumbre, llevamos a cabo análisis filogeográficos y de genética de poblaciones entre cinco subespecies de ovejas del suroccidente de Norteamérica. Analizamos 515 pb de secuencia de la región control del ADN mitocondrial y 39 microsatélites en 804 ovejas de 58 localidades. Los análisis filogenéticos revelaron 2 clados altamente divergentes concordantes con ovejas de la Sierra Nevada ( O. c. sierrae ) y de las Montañas Rocosas ( O. c. canadensis ), y demostraron que estas dos subespecies divergieron antes o durante la glaciación de Illinois (315,000-94,000 años). Las ovejas del desierto formaron varios haplogrupos recientemente derivados concordantes con las subespecies de Nelson ( O. c. nelsoni ), México ( O. c. mexicana ) y peninsular ( O. c. cremnobates ). Las estimaciones correspondientes al tiempo de separación efectiva (17,000-3,000 años) y edades de haplogrupos (85,000-72,000 años) son los plazos más probables para las divergencias entre subespecies de ovejas del desierto dentro de la última glaciación máxima. Análisis de redes de haplotipos de unión de medias y análisis bayesianos de líneas de horizonte indicaron que las ovejas del desierto formaron una población históricamente grande y diversa en términos de haplotipos, que luego perdieron gran parte de su diversidad a través de un descenso demográfico. Utilizando datos de microsatélites los análisis DAPC y TESS indicaron agrupamiento genético concordante con la distribución geográfica actual de las tres subespecies. Asimismo, comparaciones de F ST con datos de microsatélites y mitocondriales revelaron índices de fijación significativos entre los grupos genéticos de ovejas del desierto. Concluimos que estas subespecies de ovejas del desierto representan linajes antiguos que probablemente descienden de poblaciones de distintos refugios del Pleistoceno, y que por
The guide, intended to aid students (grades four and above) in making their bodies a good home for their spirit, provides a variety of athletic activities and traditional Indian recipes for use in the classroom or in cultural programs. Apart from running (the major American Indian means of maintaining physical fitness), instructions are given for…
Ysunza, Alberto M; Diez-Urdanivia, Silvia; Pérez-Gil, Sara E
Resumen: En este artículo presentamos el proyecto de capacitación llevado a cabo en comunidades de la sierra y costa de Oaxaca, México, desde 1991, por el Centro de Capacitación Integral para Promotores Comunitarios (CECIPROC). La decisión de hacer este trabajo en Oaxaca responde a que ese estado ocupa uno de los primeros lugares de marginación y de desnutrición en menores de 5 años. El objetivo es describir un modelo de capacitación y compartir parte de las experiencias derivadas, tanto del modelo como del trabajo realizado en las distintas áreas (nutrición y alimentación, salud comunitaria, ecología y etnobotánica, y educación y organización), por promotores mujeres y hombres en sus comunidades. La experiencia obtenida en 24 años muestra la factibilidad técnica y social del proyecto en el ámbito de la salud, el reconocimiento social del proyecto del CECIPROC como un organismo civil que ha aportado alternativas como solución a la problemática de salud, el hacer suyo el proyecto por algunos promotores y los diferentes obstáculos a los que se ha enfrentado. Enfatizamos el hecho de que la situación socioeconómica y política prevaleciente en el estado de Oaxaca es una limitante para el buen desarrollo de los programas colectivos de salud, e insistimos en la necesidad de compartir nuestras experiencias para que puedan ser utilizadas en la planificación y ejecución de otros proyectos.
Zimbabwe Tourist Development Corporation and its Mozambican counterpart, Empresa Nacional de Turismo , will co-operate in training programmes for...31 Afrikaners Urged To Cooperate With Moderates of Other Races (Hannes de Wet; THE STAR, 13 Aug 86) 33 - b - Official Supports Joint...Illegal Workers Targeted 54 De Klerk on Groups’ Survival 55 Minister Says Apartheid Alive 55 Police Cash Reward 55 ’Illegal Aliens’ Hiring Opposed 56
Empresas in Madrid. His Air Force contracting experience includes F-22 Fighter, C-17 Cargo Transport , and a contingency deployment as director of Joint...and the University of Maryland (University College). He has also conducted visiting seminars at American University in Cairo and Instituto de ...the long total process times that are sometimes involved in weapon system contracting, such an assessment may equate to a de facto future work
decided to create Empresa Brasileira de Aeronautica (EMBRAER). EMBRAER was a mixed public/private sector aircraft company. The government was given 51% of...the space launch market. Solid fuel missiles are easier to hide, transport , and fire than are liquid fuel systems like the Scud. These advantages make...In 1965, The Brazilian Air Force Ministry created the Space Activities Institute (IAE-Instituto de Atividades Espaciais). In 1966, the United States
Type of Report end Period Covered Ag Sponsorin ncy Na.e and Address FINAL REPORT U.S. DEPARTMENT OF TRANSPORTATION October, 1980 - June, 1982 FEDERAL...Philadelphia, Pennsylvania Weybridge, Surry England KT130SF Mr. Roy Riseley Mr. William Miles de Havilland Aircraft Cessna Aircraft Company Garratt Blvd. Wallace...Guido F. Pesotti Mr. Frank C. Davis Technical Director Engineering Specialist Empresa Brasileira Aeronautica, S.A. Garrett Turbine Engine Company
developing large, complex, software systems with long lifetimes. Those interviewed for this study who are familiar with both Ada and C++ believe that Ada is...with those who are familiar with both languages, there was a clear preference for using Ada for large complex systems with long lifetimes. These...University, December 1990 Additions by Nelson H. Weiderman, June 1991. Chile Empresa Nacional de Aeronautica (ENAER), real-time avionics system, Data
Brazilian-American Chamber of Commerce Mr. Frank J. Devine, Executive Director Embraer, Empresa Brasileira De Aeronautica Mr. Salo Roth Vice President...Throughout this study the following assumptions have been made. First, it is assumed that the reader has a basic familiarity with aircraft. Therefore...of the 5 1 weapons acquisition process. Third, the assumption is made that most readers are familiar with U.S. procedures involving the sale of
Bero, J; Beaufay, C; Hannaert, V; Hérent, M-F; Michels, P A; Quetin-Leclercq, J
Keetia leucantha is a West African tree used in traditional medicine to treat several diseases among which parasitic infections. The dichloromethane extract of leaves was previously shown to possess growth-inhibitory activities on Plasmodium falciparum, Trypanosoma brucei brucei and Leishmania mexicana mexicana with low or no cytotoxicity (>100 μg/ml on human normal fibroblasts) (Bero et al. 2009, 2011). In continuation of our investigations on the antitrypanosomal compounds from this dichloromethane extract, we analyzed by GC-FID and GC-MS the essential oil of its leaves obtained by hydrodistillation and the major triterpenic acids in this extract by LC-MS. Twenty-seven compounds were identified in the oil whose percentages were calculated using the normalization method. The essential oil, seven of its constituents and the three triterpenic acids were evaluated for their antitrypanosomal activity on Trypanosoma brucei brucei bloodstream forms (Tbb BSF) and procyclic forms (Tbb PF) to identify an activity on the glycolytic process of trypanosomes. The oil showed an IC(50) of 20.9 μg/ml on Tbb BSF and no activity was observed on Tbb PF. The best antitrypanosomal activity was observed for ursolic acid with IC(50) of 2.5 and 6.5 μg/ml respectively on Tbb BSF and Tbb PF. The inhibitory activity on a glycolytic enzyme of T. brucei, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), was also evaluated for betulinic acid, olenaolic acid, ursolic acid, phytol, α-ionone and β-ionone. The three triterpenic acids and β-ionone showed inhibitory activities on GAPDH with oleanolic acid being the most active with an inhibition of 72.63% at 20 μg/ml. This paper reports for the first time the composition and antitrypanosomal activity of the essential oil of Keetia leucantha. Several of its constituents and three triterpenic acids present in the dichloromethane leaves extract showed a higher antitrypanosomal activity on bloodstream forms of Tbb as compared to procyclic forms
de Morais, Rayana Carla Silva; da Costa Oliveira, Cintia Nascimento; de Albuquerque, Suênia da Cunha Gonçalves; Mendonça Trajano Silva, Lays Adrianne; Pessoa-E-Silva, Rômulo; Alves da Cruz, Heidi Lacerda; de Brito, Maria Edileuza Felinto; de Paiva Cavalcanti, Milena
Cutaneous leishmaniasis (CL) is a parasitic disease caused by various Leishmania species. Several studies have shown that real time quantitative PCR (qPCR) can be used for Leishmania spp. identification by analyzing the melting temperature (Tm). Thus, the aim of this study was to evaluate the viability of qPCR for differentiating eight closely related Leishmania species that cause the same clinical form of the disease and to compare the results with classical techniques. qPCR assays for standardizing the Tm using reference strains were performed. After the CL diagnosis on blood samples of domestic animals, positive samples were analyzed by their Tm and qPCR products were purified and sequenced. Ten human samples previously characterized by Multilocus Enzyme Electrophoresis (MLEE) were also analyzed by Tm. A Restriction Fragment Length Polymorphism (RFLP) assay, a reference test, was also standardized, by using the reference strains. Through standardization of Tm for Leishmania spp., two Tm ranges were created for analysis: 1 (Tm = 78-79.99 °C) included Leishmania (V.) braziliensis, Leishmania (V.) panamensis, Leishmania (V.) lainsoni, Leishmania (V.) guyanensis and Leishmania (V.) shawi; and 2 (Tm = 80-82.2 °C) included Leishmania (V.) naiffi, Leishmania (L.) amazonensis and Leishmania (L.) mexicana. A total of 223 positive blood samples were analyzed, with 58 included in range 1 and 165 in range 2. L. (V.) braziliensis, L. (V.) panamensis and L. (V.) guyanensis were identified by sequencing, while L. (V.) braziliensis, L. (L.) mexicana and L. (V.) panamensis were identified by RFLP analysis. Ten human samples previously characterized by Multilocus Enzyme Electrophoresis (MLEE) were also analyzed by qPCR Tm analysis; five were classified in range 1 and five in range 2. A concordance of 80% was calculated between qPCR and the gold-standard (MLEE) with no significant difference between the methods (p = 0.6499); a similar result was observed for sequencing
Serrano, A K; Rojas, J C; Cruz-López, L C; Malo, Edi A; Mikery, O F; Castillo, A
Lutzomyia cruciata (Coquillet) is a vector of cutaneous leishmaniasis in Mexico and Central America. However, several aspects of its ecology and behavior are unknown, including whether a male pheromone partially mediates the sexual behavior of this sand fly. In this study, we evaluated the behavioral response of females to male abdominal extracts in a Y-tube olfactometer. The volatile compounds from male abdominal extracts were identified by gas chromatography-mass spectrometry and compared with those of female abdominal extracts. Finally, the disseminating structures of the putative sex pheromone were examined by scanning electron microscopy in the male abdomen. Females were more attracted to male abdominal extract than to the hexane control, suggesting the presence of male-produced sex pheromone. The male abdominal extracts were characterized by the presence of 12 sesquiterpene compounds. The major component, an unknown sesquiterpene with an abundance of 60%, had a mass spectrum with molecular ion of m/z 262. In contrast, the abdominal female extracts contained saturated fatty acids. Finally, we detected the presence of small "papules" with a mammiform morphology distributed on the abdominal surface of tergites IV-VII of male Lu. cruciata These structures are not present in females. We conclude that Lu. cruciata males likely produce a pheromone involved in attracting or courting females. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: firstname.lastname@example.org.
Muñiz-Reyes, E; Guzmán-Franco, A W; Sánchez-Escudero, J; Nieto-Angel, R
To determine the abundance and diversity of entomopathogenic fungi in tejocote orchard soils and evaluate their ability to infect Rhagoletis pomonella Walsh., the main pest of tejocote. Surveys were made in two locations in Mexico state and two in Puebla state. Soil from selected locations was baited for entomopathogenic fungi with Galleria mellonella (L.). All isolates were identified morphologically to genus level and to species level using Bloc and elongation factor 1-α gene sequence information, respectively; Beauveria bassiana ((Bals.-Criv.) Vuill.), B. pseudobassiana (S.A. Rehner & Humber) and Metarhizium robertsii (J.F. Bisch., Rehner & Humber) were found, with B. bassiana being the most abundant and widely distributed. Pathogenicity of five selected B. bassiana isolates and three M. robertsii isolates was evaluated against larvae and pupae of R. pomonella. All isolates infected larvae resulting in an average mortality of 35%. Pupae were not susceptible; however, adults emerging from inoculated pupae did die due to infection. At least three species of entomopathogenic fungi are present in the soil from tejocote orchards, with B. bassiana being the most abundant and widely distributed. Rhagoletis pomonella larvae were more susceptible to infection than pupae. Our study has produced new information about the distribution of entomopathogenic fungi in cultivated soils from this region of North America, contributing to a better understanding of their natural occurrence and underpinning the development of biological control approaches. © 2014 The Society for Applied Microbiology.
This two-week unit, appropriate for bilingual education settings as well as foreign language programs, deals with the three primary cultural influences found in Mexican contemporary art. The multisensory materials, pragmatic focus, and direct creative student involvement are designed to make it a microcosmic, real-life experience. The first part…
Espinoza, Bertha; Martínez-Ibarra, Jose Alejandro; Villalobos, Guiehdani; De La Torre, Patricia; Laclette, Juan Pedro; Martínez-Hernández, Fernando
The triatomines vectors of Trypanosoma cruzi are principal factors in acquiring Chagas disease. For this reason, increased knowledge of domestic transmission of T. cruzi and control of its insect vectors is necessary. To contribute to genetic knowledge of North America Triatominae species, we studied genetic variations and conducted phylogenetic analysis of different triatomines species of epidemiologic importance. Our analysis showed high genetic variations between different geographic populations of Triatoma mexicana, Meccus longipennis, M. mazzottii, M. picturatus, and T. dimidiata species, suggested initial divergence, hybridation, or classifications problems. In contrast, T. gerstaeckeri, T. bolivari, and M. pallidipennis populations showed few genetics variations. Analysis using cytochrome B and internal transcribed spacer 2 gene sequences indicated that T. bolivari is closely related to the Rubrofasciata complex and not to T. dimidiata. Triatoma brailovskyi and T. gerstaeckeri showed a close relationship with Dimidiata and Phyllosoma complexes. PMID:23249692
Molina-Garza, Zinnia Judith; Bazaldúa-Rodríguez, Aldo Fabio; Quintanilla-Licea, Ramiro; Galaviz-Silva, Lucio
The aim of this study was to screen the trypanocidal activity of plants used in traditional Mexican medicine for the treatment of various diseases related to parasitic infections. Cultured Trypanosoma cruzi epimastigotes were incubated for 96h with different concentrations of methanolic extracts obtained from Artemisia mexicana, Castela texana, Cymbopogon citratus, Eryngium heterophyllum, Haematoxylum brasiletto, Lippia graveolens, Marrubium vulgare, Persea americana, Ruta chalepensis and Schinus molle. The inhibitory concentration (IC50) was determined for each extract via a colorimetric method. Among the evaluated species, the methanolic extracts of E. heterophyllum, H. brasiletto, M. vulgare and S. molle exhibited the highest trypanocidal activity, showing percentages of growth inhibition between 88 and 100% at a concentration of 150μg/ml. These medicinal plants may represent a valuable source of new bioactive compounds for the therapeutic treatment of trypanosomiasis. Copyright © 2014 Elsevier B.V. All rights reserved.
Tobler, Michael; Coleman, Seth W.; Perkins, Brian D.; Rosenthal, Gil G.
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
Bierbach, David; Klein, Moritz; Saßmannshausen, Vanessa; Schlupp, Ingo; Riesch, Rüdiger; Parzefall, Jakob; Plath, Martin
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
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.
López-Collada Estrada, María; Olvera Martínez, Rosalba
Laparoscopic surgery is well accepted as a safe technique when performed on a third trimester pregnant woman. The aim is to describe the anaesthetic management of a group of patients undergoing this type of surgery. An analysis was made of records of 6 patients in their third trimester of pregnancy and who underwent urgent laparoscopic surgery from 2011 to 2013. The study included 6 patients, with a diagnosis of acute cholecystitis in 4 of them. The other 2 patients had acute appendicitis, both of who presented threatened preterm labour. The most frequent indications for laparoscopic surgery during the last trimester of birth were found to be acute cholecystitis and acute appendicitis. Acute appendicitis is related to an elevated risk of presenting threatened preterm labour. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.
Quillo-Olvera, Javier; Uribe-Olalde, Juan Salvador; Alcántara-Gómez, Leopoldo Alberto; Rejón-Pérez, Jorge Dax; Palomera-Gómez, Héctor Guillermo
The rare incidence of primary malignant melanoma of the central nervous system and its ability to mimic other melanocytic tumors on images makes it a diagnostic challenge for the neurosurgeon. A 51-year-old patient, with a tumor located in the right forniceal callosum area. Total surgical excision was performed. Histopathological result was consistent with the diagnosis of primary malignant melanoma of the central nervous system, after ruling out extra cranial and extra spinal melanocytic lesions. The primary malignant melanoma of the central nervous system is extremely rare. There are features in magnetic resonance imaging that increase the diagnostic suspicion; nevertheless there are other tumors with more prevalence that share some of these features through image. Since there is not an established therapeutic standard its prognosis is discouraging. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.
Mao, Wei; Daligaux, Pierre; Lazar, Noureddine; Ha-Duong, Tâp; Cavé, Christian; van Tilbeurgh, Herman; Loiseau, Philippe M; Pomel, Sébastien
Leishmaniases are an ensemble of diseases caused by the protozoan parasite of the genus Leishmania. Current antileishmanial treatments are limited and present main issues of toxicity and drug resistance emergence. Therefore, the generation of new inhibitors specifically directed against a leishmanial target is an attractive strategy to expand the chemotherapeutic arsenal. GDP-Mannose Pyrophosphorylase (GDP-MP) is a prominent therapeutic target involved in host-parasite recognition which has been described to be essential for parasite survival. In this work, we produced and purified GDP-MPs from L. mexicana (LmGDP-MP), L. donovani (LdGDP-MP), and human (hGDP-MP), and compared their enzymatic properties. From a rationale design of 100 potential inhibitors, four compounds were identified having a promising and specific inhibitory effect on parasite GDP-MP and antileishmanial activities, one of them exhibits a competitive inhibition on LdGDP-MP and belongs to the 2-substituted quinoline series.
Kajikawa, Masaki; Ichiyanagi, Kenji; Tanaka, Nozomu; Okada, Norihiro
Long interspersed elements (LINEs) and short interspersed elements (SINEs) are retrotransposons. These elements can mobilize by the "copy-and-paste" mechanism, in which their own RNA is reverse-transcribed into complementary DNA (cDNA). LINEs and SINEs not only are components of eukaryotic genomes but also drivers of genomic evolution. Thus, studies of the amplification mechanism of LINEs and SINEs are important for understanding eukaryotic genome evolution. Here we report the characterization of one LINE family (UnaL2) and two SINE families (UnaSINE1 and UnaSINE2) from the eel (Anguilla japonica) genome. UnaL2 is approximately 3.6 kilobases (kb) and encodes only one open reading frame (ORF). UnaL2 belongs to the stringent type--thought to be a major group of LINEs--and can mobilize in HeLa cells. We also show that UnaL2 and the two UnaSINEs have similar 3' tails, and that both UnaSINE1 and UnaSINE2 can be mobilized by UnaL2 in HeLa cells. These elements are thus useful for delineating the amplification mechanism of stringent type LINEs as well as that of SINEs.
34Petroleo e industrializacion," Comercio Exterior , Vol. 32, (Nov 1982), p. 1213. 52. Blutstein, p. 158. 53. Ministerio de Energia y Minas, Petroleo y...tion of Guyana), and the Empresa Nacional de Pesca (National Fishing Enterprise). As will be analyzed in the next chapter, Venezuela’s develop- ment...economia venezolana en los ultimos 35 anos, p. 273. Comercio Exterior , (Nov 1982), p. 1220. Rollins, Raw Materials Development and Economic Growth: A Study
collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE 25 SEP 2009 2. REPORT TYPE 3. DATES COVERED...taught at the University of Dayton, and American University (Washington, DC) and visiting seminars at American University in Cairo, and Instituto de ... Empresas in Madrid. Dr. Reed retired from Active Military Service in 2008 after 21 years in the Air Force. Dr. Reed held various assignments in
Pursues Dream in Space," Washington Post, 13 December 1984, lf, 4f. According to Defense News, "Brazil’s Andrade Gutierrez Quimica produces ammonium...owned by Engesa (EnQenheiros Especializados S.A. - 40 percent), Embraer (Empresa Brasileira de Aeronautica S.A. - 40 percent), Esca ( Engenharia de...AeronAutica S.A. EMFA - Estado Maior das Forcas Armadas (General Staff of the Armed Forces) Engesa - Engenheiros Es~ecializados S.A. Esca - Engenharia de
www.embraer.com The EMB-314 Super Tucano is produced by Empresa Brasil De Aeronautica (EMBRAER). An advanced derivative of the EMB-312 which entered...Bronco. Built by Rockwell International, the Bronco was des igned spec i f ica l ly to f igh t l im i ted ‘brushfire’ wars and entered the LARA com...packaging, handling, storage and transportation ; computer resources; maintenance planning; support equipment; manpower & personnel; facilities; training
Instituto de Empresas de España and graduated from the Center for Hemispheric Defense Studies at the National Defense University in Washington. Captain...Base (1998–99), the Mato Grosso Flotilla (1994), and fluvial transport boat Piraim (1983). Captain Luiz Carlos de Carvalho ROTH is retired from the...Cooperation 25 CAPTAIN CLAUDIO ROGERIO DE ANDRADE FLÔR, BRAZILIAN NAVY (RETIRED) CHAPTER FIVE Toward a Maritime Strategy 33 REAR ADMIRAL MIGUEL ANGEL
Conkle, Joel; van der Haar, Frits
In 2013, the World Health Organization (WHO) called for joint surveillance of population salt and iodine intakes using urinary analysis. 24-h urine collection is considered the gold standard for salt intake assessment, but there is an emerging consensus that casual urine sampling can provide comparable information for population-level surveillance. Our review covers the use of the urinary sodium concentration (UNaC) and the urinary iodine concentration (UIC) from casual urine samples to estimate salt intakes and to partition the sources of iodine intakes. We reviewed literature on 24-h urinary sodium excretion (UNaE) and UNaC and documented the use of UNaC for national salt intake monitoring. We combined information from our review of urinary sodium with evidence on urinary iodine to assess the appropriateness of partitioning methods currently being adapted for cross-sectional survey analyses. At least nine countries are using casual urine collection for surveillance of population salt intakes; all these countries used single samples. Time trend analyses indicate that single UNaC can be used for monitoring changes in mean salt intakes. However; single UNaC suffers the same limitation as single UNaE; i.e., an estimate of the proportion excess salt intake can be biased due to high individual variability. There is evidence, albeit limited, that repeat UNaC sampling has good agreement at the population level with repeat UNaE collections; thus permitting an unbiased estimate of the proportion of excess salt intake. High variability of UIC and UNaC in single urine samples may also bias the estimates of dietary iodine intake sources. Our review concludes that repeated collection, in a sub-sample of individuals, of casual UNaC data would provide an immediate practical approach for routine monitoring of salt intake, because it overcomes the bias in estimates of excess salt intake. Thus we recommend more survey research to expand the evidence-base on predicted-UNaE from
Adapting a Common Photographic Camera to Take Pictures of the Sky. (Spanish Title: Adaptando Una Camara Fotografica Comun Para Obtener Fotografias del Cielo.) Adaptando Uma Câmera Fotográfica Manual Simples Para Fotografar o Céu
Danhoni Neves, Marcos Cesar; Pereira, Ricardo Francisco
In this paper will be introduced a method of astrophotography using a non-reflex photographic camera (a low-cost method). It will be revised some photographic processes commonly used nowadays for comparison with the aims of this paper. En este trabajo será introducido un método de astrofotografia que utiliza una cámara fotográfica non-reflex (un método de bajo costo). Serán revisados algunos procesos fotográficos comúnmente utilizados actualmente para comparación con los objetivos de este trabajo. O presente artigo procura introduzir um método de astrofotografia utilizando uma câmera fotográfica não reflex, de baixo custo. É feita uma revisão do processo fotográfico comumente empregado para fins de comparação com os objetivos pretendidos no presente trabalho.
Nat’l City Bank v. Banco Para El Comercio Exterior de Cuba, 462 U.S. 611 (1983) (“Bancec”) to judgments against designated terrorist States. Bancec held...to determine both whether an exception to the Cuban Government’s immunity from garnishment also applies to [ Empresa de Telecomunicaciones de Cuba, S.A...was eventually reversed on other grounds by the U.S. Court of Appeals for the Eleventh Circuit — Alejandre v. Telefonica Larga Distancia de Puerto Rico
designed to avoid the application of the Supreme Court decision in First Nat’l City Bank v. Banco Para El Comercio Exterior de Cuba, 462 U.S. 611 (1983...to [ Empresa de Telecomunicaciones de Cuba, S.A. (“ETECSA”)] and whether ETECSA can be held substantively liable for the Government’s debt to the...was eventually reversed on other grounds by the U.S. Court of Appeals for the Eleventh Circuit — Alejandre v. Telefonica Larga Distancia de Puerto
130 This clause appears designed to avoid the application of the Supreme Court decision in First Nat’l City Bank v. Banco Para El Comercio Exterior ...both whether an exception to the Cuban Government’s immunity from garnishment also applies to [ Empresa de Telecomunicaciones de Cuba, S.A. (“ETECSA...for the Eleventh Circuit — Alejandre v. Telefonica Larga Distancia de Puerto Rico, 183 F.3d 1277 (11th Cir. 1999). A decision by a federal district
SECTOR PUBLICO (1) Total % — Reducir los gastos militares (2) — Reducir los proyectos de inversion (3) — Aumentar los impuestos a las empresas (4...New Republic: From Poet to President (Lorem Falcao; MANCHETE, 4 May 85) 33 Poll Shows Quadros Leading Mayoral Candidate in Sao Paulo (FOLHA DE ...0 ESTADO DE SAO PAULO, 13 Jun 85) iy Sayad Proposes Three Measures To Reduce Interest Rates (0 ESTADO DE SAO PAULO, 13 Jun 85) 61 Foreign
thousands of people. In the military field, the seaplane has been virtually phased out by most countries. It is the objective of this thesis to take a...support for land-or carrier-based aircraft, leading to the virtual abandonment of seaplanes. In this thesis, Platzer’s proposal (Reference 22) to use giant... Biblioteca do ITA Centro Tecnico Aeroespacial 12 225 - Sao Jose dos Campos - SP, Brasil 14. Director da EMBRAER Empresa Brasileira de Aeronautica Sao Jose
If accurate, these astonishing numbers in themselves tell the story of Brazil’s explosive growth. 7 Embrapa is short for Empresa Brasileira de ...in the world. Geography. U.S. citizens think of Brazil as be- ing Rio de Janeiro and its beautiful beaches or as the Amazon, an endless jungle...United States www.ndu.edu/inss SF No. 266 3 and port systems lag. One study suggests that domestic transportation costs and port fees for soy, Brazil’s
Quiroga, Cristina; Cevallos, Varsovia; Morales, Diego; Baldeón, Manuel E; Cárdenas, Paúl; Rojas-Silva, Patricio; Ponce, Patricio
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.
Rivas, Nancy; Sánchez-Cordero, Víctor; Camacho, Alejandro D; Córdoba-Aguilar, Alejandro; Alejandre-Aguilar, Ricardo
Morphological characters can be used to distinguish the vast majority of triatomine species, but the existence of high levels of phenotypic plasticity and recently diverged species can lead to erroneous determinations. To approach this problem, we analyzed the male and female morphologies of the scutella of Triatoma barberi, T. dimidiata, T. lecticularia, T. mexicana, T. recurva, T. rubida, and two sub-species, T. protracta protracta and T. protracta nahuatlae. Scutellum samples were observed by scanning electron microscopy and subjected to morphological analysis and morphometric investigation using a canonical discriminant analysis. The results revealed differences primarily in central depression shape, posterior process, and vestiture. We observed clear dimension-based differences in scutellum morphometry in all the taxa under study, providing sound evidence for species and subspecies differentiation. On the other hand, there is no difference between sexes in T. lecticularia, T. protracta protracta, and T. protracta nahuatlae. Our methodology can be implemented to differentiate species of the genus Triatoma. © 2017 The Society for Vector Ecology.
Aguilar-Espinosa, Francisco; Gálvez-Romero, José Luis; Falfán-Moreno, Jesús; Guerrero-Martínez, Gustavo Adolfo; Vargas-Solís, Facundo
Gallstone ileus is a non-strangulated mechanical obstruction of the small bowel or colon as a result of the passage of gallstones through a biliary enteric fistula. It is a rare complication of cholelithiasis, affects patients over 65 years, and the disease occurs predominantly in females. Preoperative diagnosis is difficult due to the lack of specific signs and symptoms in elderly patients with multiple comorbidities. A 93-year-old female presenting with a one-week history of upper gastrointestinal bleeding, electrolyte imbalance and community- acquired pneumonia pneumonia. During her prolonged hospital stay she presented an intestinal obstruction. The diagnosis of gallstone ileus was made by CT scan. Despite surgical treatment, she died due to late diagnosis. Gallstone ileus is a rare pathology, difficulty in diagnosis prolongs hospital stay, which directly influences mortality. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.
Longoni, Silvia S; López-Cespedes, Angeles; Sánchez-Moreno, Manuel; Bolio-Gonzalez, Manuel E; Sauri-Arceo, Carlos H; Rodríguez-Vivas, Roger I; Marín, Clotilde
Although human leishmaniasis has been reported in 20 states in Mexico, no case of leishmaniasis has been reported in cats to date. In the Yucatan Peninsula, it has been found that dogs may act as reservoirs for at least three Leishmania species (Leishmania mexicana, Leishmania braziliensis, and Leishmania panamensis). In this study we identified specific antibodies against these three Leishmania spp. and Trypanosoma cruzi in the sera from 95 cats from two States on the Yucatan Peninsula, namely Quintana Roo and Yucatan, by ELISA and Western blot techniques using whole extract and an iron superoxide dismutase excreted by the parasites as antigens. As well as demonstrating the presence of trypanosomatid antibodies in the feline population on the Yucatan Peninsula, we were also able to confirm the high sensitivity and specificity of the iron superoxide dismutase antigen secreted by them, which may prove to be very useful in epidemiological studies. Copyright © 2012 Elsevier Ltd. All rights reserved.
Rogers, Matthew E; Ilg, Thomas; Nikolaev, Andrei V; Ferguson, Michael A J; Bates, Paul A
Sand flies are the exclusive vectors of the protozoan parasite Leishmania, but the mechanism of transmission by fly bite has not been determined nor incorporated into experimental models of infection. In sand flies with mature Leishmania infections the anterior midgut is blocked by a gel of parasite origin, the promastigote secretory gel. Here we analyse the inocula from Leishmania mexicana-infected Lutzomyia longipalpis sand flies. Analysis revealed the size of the infectious dose, the underlying mechanism of parasite delivery by regurgitation, and the novel contribution made to infection by filamentous proteophosphoglycan (fPPG), a component of promastigote secretory gel found to accompany the parasites during transmission. Collectively these results have important implications for understanding the relationship between the parasite and its vector, the pathology of cutaneous leishmaniasis in humans and also the development of effective vaccines and drugs. These findings emphasize that to fully understand transmission of vector-borne diseases the interaction between the parasite, its vector and the mammalian host must be considered together.
Castillo-Juárez, Israel; González, Violeta; Jaime-Aguilar, Héctor; Martínez, Gisela; Linares, Edelmira; Bye, Robert; Romero, Irma
Helicobacter pylori is the major etiological agent of chronic active gastritis and peptic ulcer disease and is linked to gastric carcinoma. Treatment to eradicate the bacteria failed in many cases, mainly due to antibiotic resistance, hence the necessity of developing better therapeutic regimens. Mexico has an enormous unexplored potential of medicinal plants. This work evaluates the in vitro anti-H. pylori activity of 53 plants used in Mexican traditional medicine for gastrointestinal disorders. To test the in vitro antibacterial activity, agar dilution and broth dilution methods were used for aqueous and methanolic extracts, respectively. Aqueous extracts of Artemisia ludoviciana subsp. mexicana, Cuphea aequipetala, Ludwigia repens,and Mentha x piperita (MIC 125 to <250 microg/ml) as well as methanolic extracts of Persea americana, Annona cherimola, Guaiacum coulteri, and Moussonia deppeana (MIC <7.5 to 15.6 microg/ml) showed the highest inhibitory effect. The results contribute to understanding the mode of action of the studied medicinal plants and for detecting plants with high anti-Helicobacter pylori activity.
Carrillo-Esper, Raúl; Galván-Talamantes, Yazmin; Meza-Ayala, Cynthia Margarita; Cruz-Santana, Julio Alberto; Bonilla-Reséndiz, Luis Ignacio
Rhabdomyolysis is defined as skeletal muscle necrosis. Ultrasound assessment has recently become a useful tool for the diagnosis and monitoring of muscle diseases, including rhabdomyolysis. A case is presented on the ultrasound findings in a patient with rhabdomyolysis. To highlight the importance of ultrasound as an essential part in the diagnosis in rhabdomyolysis, to describe the ultrasound findings, and review the literature. A 30 year-old with post-traumatic rhabdomyolysis of both thighs. Ultrasound was performed using a Philips Sparq model with a high-frequency linear transducer (5-10MHz), in low-dimensional scanning mode (2D), in longitudinal and transverse sections at the level of both thighs. The images obtained showed disorganisation of the orientation of the muscle fibres, ground glass image, thickening of the muscular fascia, and the presence of anechoic areas. Ultrasound is a useful tool in the evaluation of rhabdomyolysis. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.
Blahnik, Roger J.; Holzenthal, Ralph W.
Abstract The O. avara group of Oecetis is formally defined to include 4 described species, O. avara (Banks), O. disjuncta (Banks), O. elata Denning & Sykora, and O. metlacenis Bueno-Soria, and 15 new species. Oecetis marquesi Bueno-Soria, previously considered a member of the O. avara group, is treated as incertae sedis to species group, but is also redescribed and treated in the current work. New species described here (with their respective distributions) include: O. acciptrina (Costa Rica, Panama, Ecuador), O. agosta (Mexico), O. angularis (Guatemala to Ecuador), O. apache (SW USA), O. campana (Ecuador), O. constricta (Mexico to Ecuador, Venezuela, and Trinidad), O. houghtoni (North America), O. maritza (Costa Rica), O. mexicana (Mexico to Ecuador), O. patula (Guatemala, Nicaragua), O. protrusa (Mexico to Ecuador), O. sordida (Mexico, USA, Canada), O. tumida (Costa Rica), O. uncata (Costa Rica), and O. verrucula (Mexico to Costa Rica). A key to the species is also provided. PMID:24574849
Rincón-Rabanales, Manuel; Vargas-López, Laura I.; Adriano-Anaya, Lourdes; Salvador-Figueroa, Miguel
In this work, we studied the main characteristics of flowering, reproductive system and diversity of pollinators for the biofuel plant Jatropha curcas (L.) in a site of tropical southeastern Mexico, within its center of origin. The plants were monoecious with inflorescences of unisexual flowers. The male flowers produced from 3062–5016 pollen grains (266–647 per anther). The plants produced fruits with both geitonogamy and xenogamy, although insect pollination significantly increased the number and quality of fruits. A high diversity of flower visiting insects (36 species) was found, of which nine were classified as efficient pollinators. The native stingless bees Scaptotrigona mexicana (Guérin-Meneville) and Trigona (Tetragonisca) angustula (Latreille) were the most frequent visitors and their presence coincided with the hours when the stigma was receptive. It is noteworthy that the female flowers open before the male flowers, favoring xenogamy, which may explain the high genetic variability reported in J. curcas for this region of the world. PMID:26989640
Naidu, Ashwin; Smythe, Lindsay A.; Thompson, Ron W.; Culver, Melanie
Recent records of mountain lions Puma concolor and concurrent declines in desert bighorn sheep Ovis canadensis mexicana on Kofa National Wildlife Refuge in Arizona, United States, have prompted investigations to estimate the number of mountain lions occurring there. We performed noninvasive genetic analyses and identified species, individuals, and sex from scat samples collected from the Kofa and Castle Dome Mountains. From 105 scats collected, we identified a minimum of 11 individual mountain lions. These individuals consisted of six males, two females and three of unknown sex. Three of the 11 mountain lions were identified multiple times over the study period. These estimates supplement previously recorded information on mountain lions in an area where they were historically considered only transient. We demonstrate that noninvasive genetic techniques, especially when used in conjunction with camera-trap and radiocollaring methods, can provide additional and reliable information to wildlife managers, particularly on secretive species like the mountain lion.
Icaza-Chávez, M E
Gut microbiota is the community of live microorganisms residing in the digestive tract. There are many groups of researchers worldwide that are working at deciphering the collective genome of the human microbiota. Modern techniques for studying the microbiota have made us aware of an important number of nonculturable bacteria and of the relation between the microorganisms that live inside us and our homeostasis. The microbiota is essential for correct body growth, the development of immunity, and nutrition. Certain epidemics affecting humanity such as asthma and obesity may possibly be explained, at least partially, by alterations in the microbiota. Dysbiosis has been associated with a series of gastrointestinal disorders that include non-alcoholic fatty liver disease, celiac disease, and irritable bowel syndrome. The present article deals with the nomenclature, modern study techniques, and functions of gut microbiota, and its relation to health and disease. Copyright © 2013 Asociación Mexicana de Gastroenterología. Published by Masson Doyma México S.A. All rights reserved.
Sánchez-Cordero, Victor; Ben Beard, C.; Ramsey, Janine M.
Ecologic niche modeling may improve our understanding of epidemiologically relevant vector and parasite-reservoir distributions. We used this tool to identify host relationships of Triatoma species implicated in transmission of Chagas disease. Associations have been documented between the protracta complex (Triatoma: Triatominae: Reduviidae) with packrat species (Neotoma spp.), providing an excellent case study for the broader challenge of developing hypotheses of association. Species pairs that were identified coincided exactly with those in previous studies, suggesting that local interactions between Triatoma and Neotoma species and subspecies have implications at a geographic level. Nothing is known about sylvatic associates of T. barberi, which are considered the primary Chagas vector in Mexico; its geographic distribution coincided closely with that of N. mexicana, suggesting interaction. The presence of the species was confirmed in two regions where it had been predicted but not previously collected. This approach may help in identifying Chagas disease risk areas, planning vector-control strategies, and exploring parasite-reservoir associations for other emerging diseases. PMID:12095431
Montanari, C. A.; Tute, M. S.; Beezer, A. E.; Mitchell, J. C.
Results are presented for a QSAR analysis of bisamidines, using a similarity index as descriptor. The method allows for differences in conformation of bisamidines at the receptor site to be taken into consideration. In particular, it has been suggested by others that pentamidine binds in the minor groove of DNA in a so-called isohelical conformation, and our QSAR supports this suggestion. The molecular similarity index for comparison of molecules can be used as a parameter for correlating and hence rationalising the activity as well as suggesting the design of bioactive molecules. The studied compounds had been evaluated for potency against Leishmania mexicana amazonensis, and this potency was used as a dependent variable in a series of QSAR analyses. For the calculation of similarity indexes, each analogue was in turn superimposed on a chosen lead compound in a reference conformation, either extended or isohelical, maximising overlap and hence similarity by flexible fitting.
Orea-Martínez, J G; Pérez-Corro, M A; Contreras-Vera, R A; Bretón-Márquez, J H
We present herein the case of a 16-year-old female from the southern portion of the State of Puebla, Mexico. When gathering her past medical history, it was revealed that she had grown up with pet dogs and that her family raised sheep. Because the patient presented with few symptoms, a benign lesion was suspected, and after laparoscopic exploration, the possibility of surgical management for a non-parasitic cyst was considered. A dull pain in the right hypochondrium persisted and open surgical exploration was performed in which a 6cm young, active, uncomplicated hydatid cyst was discovered. Its surgical removal was successful and the pathologist provided the definitive diagnosis. The three layers characteristic of a parasitic cyst were present and it was histologically consistent with Echinococcus granulosus. Postoperative progression was unremarkable and the control ultrasound study revealed complete restitution of the hepatic parenchyma. Copyright © 2012 Asociación Mexicana de Gastroenterología. Published by Masson Doyma México S.A. All rights reserved.
Beaufay, Claire; Ledoux, Allison; Jansen, Olivia; Bordignon, Annélise; Zhao, Senzhi; Teijaro, Christiana N; Andrade, Rodrigo B; Quetin-Leclercq, Joëlle; Frédérich, Michel
Strychnogucine B is a bisindole alkaloid previously isolated from Strychnos icaja that possesses promising in vitro antiplasmodial properties. This compound was synthesized in four steps from (-)-strychnine. As no acute toxicity was observed at the highest tested cumulative dose of 60 mg/kg, its in vivo antimalarial activity was determined intraperitoneally at 30 mg/kg/d in a Plasmodium berghei murine model. In the Peters's 4-d suppressive test, this alkaloid suppressed the parasitaemia by almost 36% on day 5 and 60% on day 7 compared to vehicle-treated mice. In addition to this interesting antimalarial activity, it showed moderate in vitro antitrypanosomal activity but no in vivo activity in an acute Trypanosoma brucei model. It was also inactive in vitro on Leishmania mexicana promastigotes. This highlights its selective antimalarial efficacy and leads to further investigation to assess its potential as new antimalarial lead compound. Georg Thieme Verlag KG Stuttgart · New York.
Estrada-Bárcenas, Daniel A; Palacios-Vargas, José G; Estrada-Venegas, Edith; Klimov, Pavel B; Martínez-Mena, Alejandro; Taylor, Maria Lucia
Mites and the mammal pathogenic fungus Histoplasma capsulatum are the major components of bat guano microbiota. Interactions between mites and H. capsulatum were evaluated under laboratory conditions. Acarid mites, mainly Sancassania sp., were the most abundant microarthropod in the sampled guano of the Mexican bat Tadarida brasiliensis mexicana and, based on its morphology, Sancassania sp. was similar to the cosmopolitan species Sancassania sphaerogaster. The mycophagous and vectoring activities of this mite were tested for H. capsulatum and two other fungal species, Sporothrix schenckii (pathogenic) and Aspergillus sclerotiorum (non-pathogenic). S. ca. sphaerogaster was able to reproduce in H. capsulatum and S. schenckii colonies, multiplying in great numbers under controlled fungal mycelial-phase culture conditions. H. capsulatum colonies were completely destroyed after 14 days of in vitro interaction with mites. In contrast, S. ca. sphaerogaster did not reproduce in A. sclerotiorum cultures. S. ca. sphaerogaster was found vectoring H. capsulatum, but not the two other fungal species studied.
Pérez-Calatayud, Ángel Augusto; Briones-Garduño, Jesús Carlos; Álvarez-Goris, Mercedes Del Pilar; Sánchez Zamora, Ricardo; Torres Aguilar, Angélica A; Mendoza-Mórales, Rosa Elba
Atypical haemolytic uraemic syndrome is one of the main variants of thrombotic microangiopathy, and is characterized by excessive complement activation in the microvasculature. It is also characterised by the clinical triad; non-immune haemolytic anaemia, thrombocytopenia, and acute renal failure. In addition, 60% of patients have mutations in the genes encoding complement regulators (factor H, factor I, membrane cofactor proteins, and thrombomodulin), activators (factor B and C3), as well as autoantibodies against factor H. Multiple factors are required for the disease to manifest itself, including a trigger and gene mutations with adequate penetration. Being one of the differential diagnoses of preeclampsia- eclampsia and HELLP syndrome means that the clinician must be familiar with the disease due to its high mortality, which can be modified with early diagnosis and comprehensive treatment. Copyright © 2016 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.
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.
Vargas-Hernández, Víctor Manuel; Vargas-Aguilar, Víctor Manuel; Tovar-Rodríguez, José María
Cervico-uterine cancer screening with cytology decrease incidence by more than 50%. The cause of this cancer is the human papilloma virus high risk, and requires a sensitive test to provide sufficient sensitivity and specificity for early detection and greater interval period when the results are negative. The test of the human papilloma virus high risk, is effective and safe because of its excellent sensitivity, negative predictive value and optimal reproducibility, especially when combined with liquid-based cytology or biomarkers with viral load, with higher sensitivity and specificity, by reducing false positives for the detection of cervical intraepithelial neoplasia grade 2 or greater injury, with excellent clinical benefits to cervical cancer screening and related infection of human papilloma virus diseases, is currently the best test for early detection infection of human papillomavirus and the risk of carcinogenesis. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.
Benítez-Arvízu, Gamaliel; Palma-Lara, Ícela; Vazquez-Campos, René; Sesma-Villalpando, Raimundo Alfonso; Parra-Barrera, Alberto; Gutiérrez-Iglesias, Gisela
Diabetes mellitus 2 has become a global problem. It is estimated that 15% to 25% of patients could develop a chronic ulcer in their life, and nearly 33% of direct care costs of the diabetes mellitus 2 is spent on treating these ulcers. Mesenchymal stem cells have emerged as a promising cell source for the treatment of these ulcers. The case is presented of a 67 year-old male with a history of diabetes mellitus, acute myocardial infarction, and food ulcer chronic involving right foot and part of his leg. He was treated with mesenchymal stem cell management, resulting in skin graft integration and full coverage of the lesion. The implementation of mesenchymal stem cell techniques for treatment of chronic ulcer is feasible. The impact on the population would lead to a significant improvement in their quality of life and reduce healthcare spending. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.
Cevallos, Varsovia; Morales, Diego; Baldeón, Manuel E; Cárdenas, Paúl; Rojas-Silva, Patricio; Ponce, Patricio
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
Snow, Neil; Peterson, Paul M.; Romaschenko, Konstantin
Abstract Disakisperma Steud. is a genus of four predominantly perennial C4 (NAD-ME) species in the Americas, Africa, and Asia. Its species previously were treated in Eleusine, Eragrostis, Coelachyrum, Cypholepis, Leptochloa, or Diplachne by nearly all authors.It includes the widespread North and South American amphitropical disjunct Disakisperma dubium (type of the genus), Disakisperma eleusine from southern Africa, Disakisperma obtusiflorum from central and northern Africa to southern Asia, and Disakisperma yemenicum, comb. nov. from eastern and southern Africa to Yemen. This paper provides a key to the species, geographic distributions, descriptions, including comments on the anatomy of leaves, stems, lemmatal micromorphology, a phylogram based on five molecular markers, and discussions of chromosome numbers. The species are rarely, if at all, known outside of their native ranges and are unlikely to become aggressively invasive. All species are considered Least Concern following IUCN guidelines. Lectotypes are designated for Diplachne dubia var. pringleana Kuntze, Disakisperma mexicana Steud., Eragrostis yemenica Schweinf., and Leptochloa appletonii Stapf. PMID:24194669
Pasternak, Anna; Wengel, Jesper
Thermodynamics provides insights into the influence of modified nucleotide residues on stability of nucleic acids and is crucial for designing duplexes with given properties. In this article, we introduce detailed thermodynamic analysis of RNA duplexes modified with unlocked nucleic acid (UNA) nucleotide residues. We investigate UNA single substitutions as well as model mismatch and dangling end effects. UNA residues placed in a central position makes RNA duplex structure less favourable by 4.0–6.6 kcal/mol. Slight destabilization, by ∼0.5–1.5 kcal/mol, is observed for 5′- or 3′-terminal UNA residues. Furthermore, thermodynamic effects caused by UNA residues are extremely additive with ΔG°37 conformity up to 98%. Direct mismatches involving UNA residues decrease the thermodynamic stability less than unmodified mismatches in RNA duplexes. Additionally, the presence of UNA residues adjacent to unpaired RNA residues reduces mismatch discrimination. Thermodynamic analysis of UNA 5′- and 3′-dangling ends revealed that stacking interactions of UNA residues are always less favourable than that of RNA residues. Finally, circular dichroism spectra imply no changes in overall A-form structure of UNA–RNA/RNA duplexes relative to the unmodified RNA duplexes. PMID:20562222
Pérez Benítez, Carlos I.; Vicente, Benjamin; Zlotnick, Caron; Kohn, Robert; Johnson, Jennifer; Valdivia, Sandra; Rioseco, Pedro
RESUMEN Durante la década de 1990 en los Estados Unidos (EU), el conocimiento sobre el trastorno de estrés post-traumático (TEPT) evolucionó de estudios específicos en un principio, sobre veteranos de guerra y sobre víctimas de desastres, a estudios epidemiológicos más tarde, sin embargo, la epidemiología del TEPT en países en desarrollo ha sido un área poco estudiada hasta ahora. Los expertos en el área de trauma han propuesto que los sucesos traumáticos que ocurren en la niñez son más perjudiciales para la salud mental que aquellos que ocurren más tarde en la vida. Este trabajo revisa los resultados de un estudio epidemiológico llevado a cabo en Chile. Específicamente, se revisan los resultados sobre las tasas de prevalencia del TEPT, traumas asociados más frecuentemente con él, así como la comorbilidad de este trastorno con otros trastornos psiquiátricos a lo largo de la vida. Igualmente se analizaron las diferencias del TEPT en cada sexo, así como la exposición a traumas en una muestra representativa de chilenos. Además se comparó la prevalencia de trastornos psiquiátricos en personas que sufrieron su primer trauma durante la niñez, durante la edad adulta, o que no reportaron traumas durante su vida. En estos estudios epidemiológicos se usaron módulos del TEPT y trastorno de personalidad antisocial (TPA) de la entrevista diagnóstica siguiendo los criterios del DSM-III-R (DIS–III-R). Para evaluar el resto de los trastornos psiquiátricos se usó la Entrevista Diagnóstica Internacional Compuesta (CIDI). Estos instrumentos fueron administrados en tres ciudades chilenas a 2390 personas mayores de 15 años. Para estimar los errores estándares (EE) debido al diseño de la muestra y a la necesidad de ajuste se usó el método Taylor de linearización seriada. También se usó un análisis de regresión logística para examinar la relación entre el TEPT, los factores demográficos de riesgo y el tipo de trauma. Además se utilizó la
Yunta, Eduardo Rodriguez
El presente trabajo reflexiona sobre el fundamento filosófico de la bioética como disciplina, método y movimiento desde su contexto histórico y en relación con el contexto social y cultural de la vivencia latinoamericana. PMID:20209030
appears designed to avoid the application of the Supreme Court decision in First Nat’l City Bank v. Banco Para El Comercio Exterior de Cuba, 462 U.S. 611...order to determine both whether an exception to the Cuban Government’s immunity from garnishment also applies to [ Empresa de Telecomunicaciones de ...Eleventh Circuit — Alejandre v. Telefonica Larga Distancia de Puerto Rico, 183 F.3d 1277 (11th Cir. 1999). A decision by a federal district court in the
Kang, Shin Sook; Kang, Eun Hee; Kim, Seon Ok; Lee, Moo Song; Hong, Changgi D; Kim, Soon Bae
Sodium intake is an important issue for patients with chronic kidney disease (CKD). The two most widely used methods to measure sodium are 24-h urinary sodium excretion (24HUNa), which can be difficult to perform routinely, and sodium intake by dietary recall, which can be inaccurate. This study evaluated use of the mean value of three spot urinary sodium (UNa) concentrations to estimate daily sodium intake in patients with CKD. This cross-sectional study enrolled 305 patients with CKD, none of whom were on dialysis, who visited the nephrology clinic at the Asan Medical Center (Seoul, Korea). We performed three spot UNa tests, three calculations of the UNa/creatinine (UCr) ratio, one measurement of 24HUNa, and one measurement of sodium intake by dietary recall. The 24HUNa and mean spot UNa values were significantly lower in patients with more advanced CKD (P = 0.006 and P < 0.001, respectively). One-time spot UNa was significantly higher in the evening than in the morning for patients with stage III, IV, or V CKD. Total sodium intake, but not sodium nutrient density (milligrams of sodium per 1000 kcal), was significantly different for patients with different stages of CKD (P = 0.001). The correlation coefficient between 24HUNa and mean spot UNa was 0.477 (95% confidence interval [CI] 0.384-0.562, P < 0.001), slightly higher than that between 24HUNa excretion and mean spot UNa/UCr (r = 0.313, 95% CI 0.207-0.465, P < 0.001). There was a linear relation between spot UNa and 24HUNa: mean spot UNa = 0.27 × 24HUNa + 60. Therefore, a 24HUNa excretion of 87 mEq (sodium intake 2 g/d) corresponded to a mean spot UNa level of 83 mEq/L. The correlation coefficient between sodium intake and mean spot UNa was 0.435 (95% CI 0.336-0.524, P < 0.001), significantly higher than that between sodium intake and mean spot UNa/UCr (r = 0.197, 95% CI 0.091-0.301, P = 0.001). Mean spot UNa tended to be better correlated with 24HUNa than with sodium intake. Mean spot UNa is a simple and
Medina-Barrios, M.; Conde-Alvarez, C.; Gay-Garcia, C.
El impacto de la variabilidad y cambio climáticos, afectan el potencial agrícola de la Región Sur de Tamaulipas. Además de los cambios estacionales, bajos rendimientos agrícolas, el manejo de los cultivos y las políticas locales de producción, existe la incertidumbre del mercado regional para los pequeños y grandes productores. La diversificación agrícola ha sido una alternativa para enfrentar las condiciones imperantes en esta región. Pero ésta ha provocado la fragmentación territorial, por lo que sólo algunos productores logran competir en un mercado nacional. Existe una preocupación generalizada por buscar soluciones que permitan que la población que es afectada por la inseguridad de la producción agrícola y económica, pueda adaptarse a las variaciones climáticas que afectan el proceso productivo. La seguridad alimentaría queda sujeta a la fluctuación de las importaciones para los sectores básicos y a las estrategias mercantiles de empresas trasnacionales. La percepción local sugiere un número creciente de eventos climatológicos extremos, constantes y severos en los últimos 20 años, con el aumento creciente de pérdidas económicas. El análisis se centra en la disponibilidad de agua, agregándose un aspecto de capital importancia como es la variabilidad interanual de la lluvia, que condiciona muy fuertemente el riesgo agrícola en el trópico seco, siendo ésta la que determina el momento de inicio de la estación favorable para el crecimiento y su duración. En este trabajo se han obtenido modelos de la distribución espacial de la precipitación y temperaturas, para el escenario base 1961-1990, el escenario actual 1971-2000, para algunos años El Niño y La Niña, así como para los escenarios de Cambio Climático HADLEY, ECHAM y GFDL, con escenarios A2 y B2, para las décadas de los 20s y 50s, para establecer el inicio y duración de la Estación de Crecimiento, utilizando Sistemas de Información Geográfica (ArcView). Estos
mortality but did not provide sterile immunity. RESUMEN. La vacunación del cuervo Americano (Corvus brachyrhynchos) con vacuna de ADN proporciona...casi 100% fatal en el cuervo Americano (Corvus brachyrhynchos). Evaluamos cuatro formulaciones de vacunas en cuervos Americanos, incluyendo una vacuna de...ADN, una vacuna de ADN con adyuvante, ambas aplicadas por la vı́a intramuscular, una vacuna de ADN microencapsulada aplicada por la vı́a oral, y una
80.7] G. Buoro, G. Pavesi and G. Zucchiatti, "Osservazioni sul Sistema di Calcolo del Margine di Solvabiliti," 71-80. [80.8] J. Calcanis and A...Vegas, "Un Ensayo sobre la Concepci6n Sistema aplicada a la Empresa de Seguros," 443-462. [80.41] K. H. Wolff, "Zur numerischen Berechnung der... Teoria della Credibilit&," Giornale dell’ Istituto degli Attuari, 27, 219-231 (1964). (D51 N. De Pril, "The Efficiency of a Bonus-Malus System," AB, 10
Cavenago, Dario; Mezzanzanica, Mario
I servizi sono oramai centrali nella vita sociale di ogni Paese. L'aspettativa di ogni attore sociale, sia esso cittadino/utente e/o istituzione, è quella di ricevere da uno scambio che ha alla base un servizio un contributo che si caratterizza per una qualità intrinseca. Il mantenimento di tale promessa richiede all'azienda erogatrice un forte coinvolgimento, nel disegno del servizio, degli utenti ed una capacità di gestione della conoscenza; ciò è particolarmente significativo per quei servizi che si caratterizzano per una forte personalizzazione o complessità progettuale. Disegnare un servizio, metterlo in produzione e gestirne l'erogazione ha una complessità variabile in base al grado di coinvolgimento dei destinati ed alle dimensioni critiche che esprimono le condizioni di fattibilità di un servizio di qualità appropriato alle attese degli utilizzatori. Ugualmente la globalizzazione dell'economia e la scarsità delle risorse ha portato l'attenzione, ai fini della sostenibilità delle condizioni sopra richiamate, di una ricerca di modelli e strumenti che permettano una valutazione e una standardizzazione dei processi di produzione ed erogazione secondo condizioni di economicità. Tali primi e sintetici elementi hanno condotto diversi attori istituzionali, grandi imprese ed università attraverso i loro centri di ricerca, ad una azione di riflessione sul grado di "ingegnerizzazione" dei processi sottesi alla erogazione dei servizi ed in particolare ai servizi che attuano le politiche dei grandi settori di base dell'economia di una Nazione: educazione, sanità, sociale, sviluppo infrastrutture ecc.
Gand, Elise; Ragot, Stéphanie; Bankir, Lise; Piguel, Xavier; Fumeron, Frédéric; Halimi, Jean-Michel; Marechaud, Richard; Roussel, Ronan; Hadjadj, Samy; Study group, SURDIAGENE
Objective. Sodium intake is associated with cardiovascular outcomes. However, no study has specifically reported an association between cardiovascular mortality and urinary sodium concentration (UNa). We examined the association of UNa with mortality in a cohort of type 2 diabetes (T2D) patients. Methods. Patients were followed for all-cause death and cardiovascular death. Baseline UNa was measured from second morning spot urinary sample. We used Cox proportional hazard models to identify independent predictors of mortality. Improvement in prediction of mortality by the addition of UNa to a model including known risk factors was assessed by the relative integrated discrimination improvement (rIDI) index. Results. Participants (n = 1,439) were followed for a median of 5.7 years, during which 254 cardiovascular deaths and 429 all-cause deaths were recorded. UNa independently predicted all-cause and cardiovascular mortality. An increase of one standard deviation of UNa was associated with a decrease of 21% of all-cause mortality and 22% of cardiovascular mortality. UNa improved all-cause and cardiovascular mortality prediction beyond identified risk factors (rIDI = 2.8%, P = 0.04 and rIDI = 4.6%, P = 0.02, resp.). Conclusions. In T2D, UNa was an independent predictor of mortality (low concentration is associated with increased risk) and improved modestly its prediction in addition to traditional risk factors. PMID:28255559
Kotkowiak, Weronika; Czapik, Tomasz; Pasternak, Anna
Thrombin binding aptamer (TBA), is a short DNA 15-mer that forms G-quadruplex structure and possesses anticoagulant properties. Some chemical modifications, including unlocked nucleic acids (UNA), 2'-deoxy-isoguanosine and 2'-deoxy-4-thiouridine were previously found to enhance the biological activity of TBA. In this paper, we present thermodynamic and biological characteristics of TBA variants that have been modified with novel isoguanine derivative of UNA as well as isoguanosine. Additionally, UNA-4-thiouracil and 4-thiouridine were also introduced simultaneously with isoguanine derivatives. Thermodynamic analysis indicates that the presence of isoguanosine in UNA or RNA series significantly decreases the stability of G-quadruplex structure. The highest destabilization is observed for substitution at one of the G-tetrad position. Addition of 4-thiouridine in UNA or RNA series usually decreases the unfavorable energetic cost of the presence of UNA or RNA isoguanine. Circular dichroism and thermal denaturation spectra in connection with thrombin time assay indicate that the introduction of UNA-isoguanine or isoguanosine into TBA negatively affects G-quadruplex folding and TBA anticoagulant properties. These findings demonstrate that the highly-ordered structure of TBA is essential for inhibition of thrombin activity.
mechanical energy . The object is assumed to start from rest at a point on the curve of zero slope. The launch speed and angle are calculated for the...Conservation of mechanical energy . Resumen Una ecuación general se deriva para un punto a lo largo de una trayectoria curvada descendente, de una partícula...porque no puede alcanzar la velocidad de un objeto en caída libre que coincide superficialmente con una trayectoria de este tipo. Palabras clave
velocidades radiales de la estrella o Cas de los espectros tomados entre 1992 y 2008 en Ondřejov y Dominion Astrophysical Observatory nos permitieron...orbitales de este sistema SB1 implican una función de masa muy alta de alrededor de una masa solar. Esto implica una masa muy alta de la estrella ...secundaria, posiblemente mayor que la de la estrella primaria. Para comprobar si hay la existencia de una secundaria tan masiva, o Cas fue observada con
Alcocer, Javier; Lugo, Alfonso; Marín, Luis E.; Escobar, Elva
recreativas, para determinar su potencial de uso como fuente de abastecimiento de agua potable. La mayor parte de los parámetros excedieron los criterios establecidos en la Norma Mexicana para Agua Potable (NMAP), sin embargo, como éstas no representan una riesgo para la salud, el agua de cuatro de los cinco cenotes puede ser emplada como fuente de abastecimiento de agua potable. Los contaminantes comúnes del agua subterránea de la península de Yucatán, coliformes fecales y nitratos, se encuentran en la mayoría de los casos por debajo de la NMAP (0-460 NMP/ 100ml y 0.31-1.18mg/l, respectivamente). A pesar de que estos cuatro cenotes cumplen con la NMAP, es necesario desarrollar una política de manejo adecuada del agua subterránea para evitar la contaminación de este recurso (fecal y por nitratos), así como la intrusión de agua salina.
Within the everyday space of their modest trailer homes, I observed compelling environments in the households of 5 Mexican families. In their homes, there existed "los padres con sus hijos" (parents with their children) who intuitively expressed "cariño," or love, for one another, conversed in multiple languages, practiced…
Gomez, H.C.; Zadeh, K.N.; Meyer, R.C.
The municipal electric utility of Empresas Publicas de Medellin (EPM) in Medellin, Colombia, has completed the installation and testing of their new control center. These facilities, which include all the functions expected from a modern control center, were implemented through carefully monitored and executed project stages, which are described in this article. EPM generates and transmits 1400 MW of exclusively hydroelectric energy to their service territory of the city of Medellin and nine neighboring cities and 77 smaller cities. The EPM system load ranges from 400 MW to 1200 MW.
Jacobs, Anne C.; Fair, Jeanne Marie
In recent years, the bacteria-killing assay (BKA) has become a popular technique among ecoimmunologists. New variations of that assay allow researchers to use smaller volumes of blood, an important consideration for those working on small-bodied animals. However, this version of the assay requires access to a lab with a nanodrop spectrophotometer, something that may not be available in the field. One possible solution is to freeze plasma for transport; however, this assumes that frozen plasma samples will give comparable results to fresh ones. Here, we tested this assumption using plasma samples from three species of birds: chickens (Gallus gallus), ash-throatedmore » flycatchers (Myiarchus cinerascens), and western bluebirds (Sialia mexicana). Chicken plasma samples lost most or all of their bacterial killing ability after freezing. This did not happen in flycatchers and bluebirds; however, frozen plasma did not produce results comparable to those obtained using fresh plasma. Finally, we caution researchers using the BKA to use fresh samples whenever possible, and to validate the use of frozen samples on a species-by-species basis.« less
Jiménez Gómez, Marta; Navarro-Sánchez, Antonio; Lima Sánchez, Jaime; Hernández Hernández, Juan Ramón
The principles of perineal reconstructive surgery comprise adequate filling of the defect along with stable and durable skin coverage, with a low morbidity rate. Two-flap perineal reconstruction is a simple, fast and reliable technique that uses a single donor site. This improves scar position with low morbidity. It is based in the use of 2flaps; one flap fills the defect with a «turn over» technique and the other is a rotation - advancement flap for skin coverage. A 52-year-old male diagnosed with Lynch syndrome who underwent laparoscopic abdominoperineal amputation for adenocarcinoma of the lower rectum and developed recurrence 2years later over the perineal scar that required radical resection and perineal reconstruction. The use of this approach facilitates perineal reconstruction and enables treatment of patients with large and complex defects in frequently irradiated tissues where wound dehiscence and infection are common. Copyright © 2017 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.
Santín-Rivero, Jorge; Núñez-García, Edgar; Aguirre-García, Manuel; Hagerman-Ruiz-Galindo, Gonzalo; de la Vega-González, Francisco; Moctezuma-Velasco, Carla Rubi
Small bowel volvulus is a rare cause of intestinal obstruction in adult patients. This disease is more common in children and its aetiology and management is different to that in adults. A 30 year-old male with sarcoidosis presents with acute abdomen and clinical data of intestinal obstruction. Small bowel volvulus is diagnosed by a contrast abdominal tomography and an exploratory laparotomy is performed with devolvulation and no intestinal resection. In the days following surgery, he developed a recurrent small bowel volvulus, which was again managed with surgery, but without intestinal resection. Medical treatment for sarcoidosis was started, and with his clinical progress being satisfactory,he was discharged to home. Making an early and correct diagnosis of small bowel volvulus prevents large intestinal resections. Many surgical procedures have been described with a high rate of complications. Therefore, conservative surgical management (no intestinal resection) is recommended as the best treatment with the lowest morbidity and mortality rate. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.
Wan, Chunli; Sun, Supu; Lee, Duu-Jong; Liu, Xiang; Wang, Li; Yang, Xue; Pan, Xiangliang
This study applied a novel strategy to rapid startup of partial nitrification in continuous-flow reactor using aerobic granules. Mature aerobic granules were first cultivated in a sequencing batch reactor at high chemical oxygen demand in 16 days. The strains including the Pseudoxanthomonas mexicana strain were enriched in cultivated granules to enhance their structural stability. Then the cultivated granules were incubated in a continuous-flow reactor with influent chemical oxygen deamnad being stepped decreased from 1,500 ± 100 (0-19 days) to 750 ± 50 (20-30 days), and then to 350 ± 50 mg l(-1) (31-50 days); while in the final stage 350 mg l(-1) bicarbonate was also supplied. Using this strategy the ammonia-oxidizing bacterium, Nitrosomonas europaea, was enriched in the incubated granules to achieve partial nitrification efficiency of 85-90% since 36 days and onwards. The partial nitrification granules were successfully harvested after 52 days, a period much shorter than those reported in literature. Copyright © 2013 Elsevier Ltd. All rights reserved.
Aiza-Haddad, I; Ballesteros-Amozurrutia, A; Borjas-Almaguer, O D; Castillo-Barradas, M; Castro-Narro, G; Chávez-Tapia, N; Chirino-Sprung, R A; Cisneros-Garza, L; Dehesa-Violante, M; Flores-Calderón, J; Flores-Gaxiola, A; García-Juárez, I; González-Huezo, M S; González-Moreno, E I; Higuera-de la Tijera, F; Kershenobich-Stalnikowitz, D; López-Méndez, E; Malé-Velázquez, R; Marín-López, E; Mata-Marín, J A; Méndez-Sánchez, N; Monreal-Robles, R; Moreno-Alcántar, R; Muñoz-Espinosa, L; Navarro-Alvarez, S; Pavia-Ruz, N; Pérez-Ríos, A M; Poo-Ramírez, J L; Rizo-Robles, M T; Sánchez-Ávila, J F; Sandoval-Salas, R; Torre, A; Torres-Ibarra, R; Trejo-Estrada, R; Velarde-Ruiz Velasco, J A; Wolpert-Barraza, E; Bosques-Padilla, F
The aim of the Mexican Consensus on the Treatment of HepatitisC was to develop clinical practice guidelines applicable to Mexico. The expert opinion of specialists in the following areas was taken into account: gastroenterology, infectious diseases, and hepatology. A search of the medical literature was carried out on the MEDLINE, EMBASE, and CENTRAL databases through keywords related to hepatitisC treatment. The quality of evidence was subsequently evaluated using the GRADE system and the consensus statements were formulated. The statements were then voted upon, using the modified Delphi system, and reviewed and corrected by a panel of 34 voting participants. Finally, the level of agreement was classified for each statement. The present guidelines provide recommendations with an emphasis on the new direct-acting antivirals, to facilitate their use in clinical practice. Each case must be individualized according to the comorbidities involved and patient management must always be multidisciplinary. Copyright © 2018 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.
Sangil, Carlos; Sansón, Marta; Afonso-Carrillo, Julio; Herrera, Rogelio; Rodríguez, Adriana; Martín-García, Laura; Díaz-Villa, Tania
The present work analysed the main changes in subtidal algal assemblages in the last decade in an oceanic archipelago (Canary Islands--eastern Atlantic Ocean). Changes result from increases in cover of ephemeral benthic algae, such as the non-native chlorophyte Pseudotetraspora marina and the native cyanophytes Blennothrix lyngbyacea, Schizothrix calcicola and Schizothrix mexicana. Ephemeral algae overgrow subtidal assemblages which are extensively dominated by Lobophora variegata, but competitively do not exclude other species. Increases in the abundance of species coincided with a warming of about 2 °C in surface seawater temperature (SST) linked to the weakening of the Cold Canary Current and the Northwestern African upwelling. Shifts in the distribution and cover of ephemeral species follow the SST gradient from warmer waters in the western islands to colder waters in the eastern ones. While in the warmest western islands, species have spread quickly colonizing all type of substrates in just a few years (2005-2008), the occurrence of ephemerals towards the coldest eastern islands is yet inconspicuous. Copyright © 2012 Elsevier Ltd. All rights reserved.
Non-alcoholic fatty liver disease is the most prevalent hepatopathy, estimated at 30% in the general population. In the coming years, it will likely be the most common indication for liver transplantation and the most frequent cause of hepatocellular carcinoma. Current treatment for non-alcoholic fatty liver disease is based on dietary and exercise interventions that have been shown to be efficacious, even for reverting fibrosis. Unfortunately, compliance with general measures involving lifestyle modifications is very poor, making pharmacologic strategies a necessary option. At present, there are no treatments for non-alcoholic fatty liver disease approved by regulatory agencies, and the only ones with sufficient evidence and recommended by international societies are treatments with pioglitazone and vitamin E, which are not exempt from adverse effects. We review herein the current management of non-alcoholic fatty liver disease, including dietary and physical activity interventions, available treatments, equivocal therapies, emerging treatments, and treatments presently in clinical trials. Copyright © 2018 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.
Pérez Y López, N; Lugo-Zamudio, G; Barbosa-Cobos, R E; Wong-Lam, A; Torres-López, E
Scleroderma can present with esophageal involvement causing important morbidity. To describe the manometric findings and clinical characteristics of patients with scleroderma and esophageal symptoms. Patients with scleroderma and esophageal symptoms were evaluated through esophageal manometry within the time frame of one year. Descriptive statistics were carried out and the continuous variables were expressed as means and standard deviation. Frequencies were expressed as percentages. The study included 24 female patients with a mean age of 53.5 years and mean disease progression of 7.84 years. The most frequent findings were short and hypotonic lower esophageal sphincter (mean length 1.58cm and mean tone 9.49mmHg) and ineffective esophageal motility (mean non-transmitted waves 92.91%, mean effective primary peristalsis 40.05%, and mean amplitude 13.11mmHg). The most frequent symptom was dysphagia. Scleroderma is associated with lower esophageal sphincter alterations and symptomatic ineffective esophageal motility. Copyright © 2017 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.
Grunert, Patrick; Piller, Werner E.
SEM-based investigations of porosity and test wall ultrastructure of Recent costate and non-costate Bulimina species reveal significant differences in pore diameter, pore density and ultrastructural architecture between these two groups. Costate tests of B. inflata and B. mexicana display low pore density, a large pore diameter, and test walls built by a single type of columnar ultrastructural elements. In contrast, non-costate tests of B. aculeata and B. marginata are characterized by significantly higher pore density, smaller pore diameter, and an additional type of ultrastructural elements formed by oblique, tabular crystallite units which encase the pore channels. We interpret the observed combination of traits in B. aculeata and B. marginata as a set of adaptations to poorly oxygenated, intermediate to deep infaunal microhabitats which they typically occupy today. The evolutionary trend towards increased pore density in this group seemingly involved a major modification of the biomineralisation process resulting in the lining of pore channels with a specific type of ultrastructural element to ensure stability of the densely perforated test.
Gebhardt, J S; Nierzwicki-Bauer, S A
Symbiotically associated cyanobacteria from Azolla mexicana and Azolla pinnata were isolated and cultured in a free-living state. Morphological analyses revealed differences between the free-living isolates and their symbiotic counterparts, as did restriction fragment length polymorphism (RFLP) analyses with both single-copy glnA and rbcS gene probes and a multicopy psbA gene probe. RFLP analyses with Anabaena sp. strain PCC 7120 nifD excision element probes, including an xisA gene probe, detected homologous sequences in DNA extracted from the free-living isolates. Sequences homologous to these probes were not detected in DNA from the symbiotically associated cyanobacteria. These analyses indicated that the isolates were not identical to the major cyanobacterial symbiont species residing in leaf cavities of Azolla spp. Nevertheless, striking similarities between several free-living isolates were observed. In every instance, the isolate from A. pinnata displayed banding patterns virtually identical to those of free-living cultures previously isolated from Azolla caroliniana and Azolla filiculoides. These results suggest the ubiquitous presence of a culturable minor cyanobacterial symbiont in at least three species of Azolla. Images PMID:1685078
Gonçalves; Oliveira; Körner; Poschadel; Schlupp
Video playbacks have been successfully applied to the study of visual communication in several groups of animals. However, this technique is controversial as video monitors are designed with the human visual system in mind. Differences between the visual capabilities of humans and other animals will lead to perceptually different interpretations of video images. We simultaneously presented males and females of the peacock blenny, Salaria pavo, with a live conspecific male and an online video image of the same individual. Video images failed to elicit appropriate responses. Males were aggressive towards the live male but not towards video images of the same male. Similarly, females courted only the live male and spent more time near this stimulus. In contrast, females of the gynogenetic poecilid Poecilia formosa showed an equal preference for a live and video image of a P. mexicana male, suggesting a response to live animals as strong as to video images. We discuss differences between the species that may explain their opposite reaction to video images. Copyright 2000 The Association for the Study of Animal Behaviour.
González, Camila; Rebollar-Téllez, Eduardo A.; Ibáñez-Bernal, Sergio; Becker-Fauser, Ingeborg; Martínez-Meyer, Enrique; Peterson, A. Townsend; Sánchez-Cordero, Víctor
Leishmaniases are a group of vector-borne diseases with different clinical manifestations caused by parasites transmitted by sand fly vectors. In Mexico, the sand fly Lutzomyia olmeca olmeca is the only vector proven to transmit the parasite Leishmania mexicana to humans, which causes leishmaniasis. Other vector species with potential medical importance have been obtained, but their geographic distributions and relation to transmission areas have never been assessed. We modeled the ecological niches of nine sand fly species and projected niches to estimate potential distributions by using known occurrences, environmental coverages, and the algorithms GARP and Maxent. All vector species were distributed in areas with known recurrent transmission, except for Lu. diabolica, which appeared to be related only to areas of occasional transmission in northern Mexico. The distribution of Lu. o. olmeca does not overlap with all reported cutaneous leishmaniasis cases, suggesting that Lu. cruciata and Lu. shannoni are likely also involved as primary vectors in those areas. Our study provides useful information of potential risk areas of leishmaniasis transmission in Mexico. PMID:22049037
This guide contains vital information for anyone wishing to visit, explore, and photograph active volcanoes safely and enjoyably. Following an introduction that discusses eruption styles of different types of volcanoes and how to prepare for an exploratory trip that avoids volcanic dangers, the book presents guidelines to visiting 42 different volcanoes around the world. It is filled with practical information that includes tour itineraries, maps, transportation details, and warnings of possible non-volcanic dangers. Three appendices direct the reader to a wealth of further volcano resources in a volume that will fascinate amateur enthusiasts and professional volcanologists alike. Rosaly Lopes is a planetary geology and volcanology specialist at the NASA Jet Propulsion Laboratory in California. In addition to her curatorial and research work, she has lectured extensively in England and Brazil and written numerous popular science articles. She received a Latinas in Science Award from the Comision Feminil Mexicana Nacional in 1991 and since 1992, has been a co-organizer of the United Nations/European Space Agency/The Planetary Society yearly conferences on Basic Science for the Benefit of Developing Countries.
Margos, Gabriele; Lane, Robert S; Fedorova, Natalia; Koloczek, Johannes; Piesman, Joseph; Hojgaard, Andrias; Sing, Andreas; Fingerle, Volker
Two species of the genus Borrelia , Borrelia bissettiae sp. nov. and Borrelia californiensis sp. nov., were first described by Postic and co-workers on the basis of genetic analyses of several loci. Multilocus sequence analysis of eight housekeeping loci confirmed that these two Borrelia genomospecies are distinct members of the Borrelia burgdorferi sensu lato complex. B. bissettiae sp. nov. was initially described in transmission cycles involving Neotoma fuscipes wood rats and Ixodes pacificus ticks in California, and Neotoma mexicana and Ixodes spinipalpis in Colorado. The preferred host of B. californiensis sp. nov. appears to be the California kangaroo rat, Dipodomys californicus ; Ixodes jellisoni , I. spinipalipis and I. pacificus ticks are naturally infected with it. Thus, the ecological associations of the two genomospecies and their genetic distance from all other known Borrelia genomospecies species justify their description as separate genomospecies: B. bissettiae sp. nov. (type strain DN127 T = DSM 17990 T = CIP 109136 T ) and B. californiensis (type strain CA446 T = DSM 17989 T = ATCC BAA-2689 T ).
Valdespino-Gómez, Víctor Manuel; Valdespino-Castillo, Patricia Margarita; Valdespino-Castillo, Víctor Edmundo
Nowadays, cellular physiology is best understood by analysing their interacting molecular components. Proteins are the major components of the cells. Different proteins are organised in the form of functional clusters, pathways or networks. These molecules are ordered in clusters of receptor molecules of extracellular signals, transducers, sensors and biological response effectors. The identification of these intracellular signaling pathways in different cellular types has required a long journey of experimental work. More than 300 intracellular signaling pathways have been identified in human cells. They participate in cell homeostasis processes for structural and functional maintenance. Some of them participate simultaneously or in a nearly-consecutive progression to generate a cellular phenotypic change. In this review, an analysis is performed on the main intracellular signaling pathways that take part in the cellular proliferation process, and the potential use of some components of these pathways as target for therapeutic interventionism are also underlined. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.
Jacobs, Anne C; Fair, Jeanne M
In recent years, the bacteria-killing assay (BKA) has become a popular technique among ecoimmunologists. New variations of that assay allow researchers to use smaller volumes of blood, an important consideration for those working on small-bodied animals. However, this version of the assay requires access to a lab with a nanodrop spectrophotometer, something that may not be available in the field. One possible solution is to freeze plasma for transport; however, this assumes that frozen plasma samples will give comparable results to fresh ones. We tested this assumption using plasma samples from three species of birds: chickens (Gallus gallus), ash-throated flycatchers (Myiarchus cinerascens), and western bluebirds (Sialia mexicana). Chicken plasma samples lost most or all of their bacterial killing ability after freezing. This did not happen in flycatchers and bluebirds; however, frozen plasma did not produce results comparable to those obtained using fresh plasma. We caution researchers using the BKA to use fresh samples whenever possible, and to validate the use of frozen samples on a species-by-species basis. Copyright © 2015 Elsevier Inc. All rights reserved.
Riesch, Rüdiger; Plath, Martin; Schlupp, Ingo
Divergent selection through biotic factors like predation or parasitism can promote reproductive isolation even in the absence of geographical barriers. On the other hand, evidence for a role of adaptation to abiotic factors during ecological speciation in animals is scant. In particular, the role played by perpetual darkness in establishing reproductive isolation in cave animals (troglobites) remains elusive. We focused on two reproductively isolated ecotypes (surface- and cave-dwelling) of the widespread livebearer Poecilia mexicana, and raised offspring of wild-caught females to sexual maturity in a 12-month common-garden experiment. Fish were reared in light or darkness combined with high- or low-food conditions. Females, but not males, of the surface ecotype suffered from almost complete reproductive failure in darkness, especially in the low-food treatment. Furthermore, surface fish suffered from a significantly higher rate of spontaneous, stress-related infection with bacterial columnaris disease. This experimental evidence for strong selection by permanent darkness on non-adapted surface-dwelling animals adds depth to our understanding of the selective forces establishing and maintaining reproductive isolation in cave faunas. PMID:21561964
Muñoz-Guerrero, Félix; Muñoz-Solís, Adrián Antonio; Ornelas-Aguirre, José Manuel
Aplasia cutis congenita (ACC) is a skin condition of rare presentation, this disease is characterized by absence of skin at birth and associated with facial, skin and bone skull deformities. The diagnosis is mainly clinical. Male 5 days after birth, unique product of primigravida mother and no family history of relevance. Physical examination revealed bilateral and symmetrical skin defects of both lower extremities, the disease is characterized by skin fragility, scabs, and coated pseudomembrane ulcers, decreased interdigital space between toes of the left foot, retraction of the foot and genu varum. It was handled with allograft of epidermis cultured in vitro, general wound care and clinical follow-up. ACC associated with epidermolysis bullosa is one of the rarer forms of presentation. It is necessary to rule out other skin diseases. Clinical management is recommended with biological or synthetic skin cover, infection prevention, early treatment of complications and clinical follow. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.
Turumin, J L; Shanturov, V A; Turumina, H E
The basic function of the gallbladder in humans is one of protection. The accumulation of the primary bile acids (cholic acid and chenodeoxycholic acid) in the gallbladder reduces the formation of the secondary bile acids (deoxycholic acid and lithocholic acid), thus diminishing their concentration in the so-called gallbladder-independent enterohepatic circulation and protecting the liver, the stomach mucosa, the gallbladder, and the colon from their toxic hydrophobic effects. The presence or absence of the gallbladder in mammals is a determining factor in the synthesis of hydrophobic or hydrophilic bile acids. Because the gallbladder contracts 5-20 min after food is in the stomach and the "gastric chyme" moves from the stomach to the duodenum 1-3 h later, the function of the gallbladder bile in digestion may be insignificant. The aim of this article was to provide a detailed review of the role of the gallbladder and the mechanisms related to bile formation in humans. Copyright © 2012 Asociación Mexicana de Gastroenterología. Published by Masson Doyma México S.A. All rights reserved.
Jacobs, Anne C.; Fair, Jeanne Marie
In recent years, the bacteria-killing assay (BKA) has become a popular technique among ecoimmunologists. New variations of that assay allow researchers to use smaller volumes of blood, an important consideration for those working on small-bodied animals. However, this version of the assay requires access to a lab with a nanodrop spectrophotometer, something that may not be available in the field. One possible solution is to freeze plasma for transport; however, this assumes that frozen plasma samples will give comparable results to fresh ones. Here, we tested this assumption using plasma samples from three species of birds: chickens (Gallus gallus), ash-throatedmore » flycatchers (Myiarchus cinerascens), and western bluebirds (Sialia mexicana). Chicken plasma samples lost most or all of their bacterial killing ability after freezing. This did not happen in flycatchers and bluebirds; however, frozen plasma did not produce results comparable to those obtained using fresh plasma. Finally, we caution researchers using the BKA to use fresh samples whenever possible, and to validate the use of frozen samples on a species-by-species basis.« less
Fang, Zhou; Pyhäjärvi, Tanja; Weber, Allison L.; Dawe, R. Kelly; Glaubitz, Jeffrey C.; González, José de Jesus Sánchez; Ross-Ibarra, Claudia; Doebley, John; Morrell, Peter L.; Ross-Ibarra, Jeffrey
Chromosomal inversions are thought to play a special role in local adaptation, through dramatic suppression of recombination, which favors the maintenance of locally adapted alleles. However, relatively few inversions have been characterized in population genomic data. On the basis of single-nucleotide polymorphism (SNP) genotyping across a large panel of Zea mays, we have identified an ∼50-Mb region on the short arm of chromosome 1 where patterns of polymorphism are highly consistent with a polymorphic paracentric inversion that captures >700 genes. Comparison to other taxa in Zea and Tripsacum suggests that the derived, inverted state is present only in the wild Z. mays subspecies parviglumis and mexicana and is completely absent in domesticated maize. Patterns of polymorphism suggest that the inversion is ancient and geographically widespread in parviglumis. Cytological screens find little evidence for inversion loops, suggesting that inversion heterozygotes may suffer few crossover-induced fitness consequences. The inversion polymorphism shows evidence of adaptive evolution, including a strong altitudinal cline, a statistical association with environmental variables and phenotypic traits, and a skewed haplotype frequency spectrum for inverted alleles. PMID:22542971
Herrera-Gómez, Ángel; García-Pérez, Leticia; Gallardo-Alvarado, Leny; Isla-Ortiz, David; Salcedo-Hernández, Rosa A; Chanona-Vilchis, José
Androgen insensitivity syndrome is an X-linked disorder, and is characterised by a female phenotype in a chromosomally male individual. It usually occurs in puberty with primary amenorrhoea or as an inguinal tumour in a female infant. In recent years, it is often also diagnosed in fertility clinics in adulthood. The case is presented of a pure seminoma in a woman with the reference diagnosis of inguinal hernia. A 53 year old woman, who was operated on in 2014 due to a nodule in left groin. Androgen insensitivity syndrome was corroborated, and histopathology reported it as a right testicular seminoma. The importance of early diagnosis is discussed, highlighting the consequences of misdiagnosis, and question whether these patients have been adequately treated in the past. The risk of malignant transformation of an undescended testicle increases with age, thus gonadectomy should be performed after puberty, and in some cases hormone replacement therapy. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.
Gutiérrez Samperio, César; Ruiz Canizales, Raúl; Arellano Rodríguez, Salvador; Romero Zepeda, Hilda; Hall, Robert T; García Camino, Bernardo
The concepts and background of palliative medicine, the patient-health team relationship and the right of the patients to receive palliative care, its application in surgery, the criterion defining the terminally ill, proportionate and disproportionate measures, where it is applied and what this consists of, drugs and procedures used, who should administrate them and for how long, the requirements for advanc directives and avoidance of therapeutic obstinacy, were reviewed. It describes and reflects their ethical and legal bases. It describes the main changes to the law in México in 2009 and 2012. It concludes that palliative medicine is not against scientific and technological progress, but promotes its appropriate use with respect to the will and dignity of the patient. It should be applied by a multidisciplinary team, who accompany the patient throughout the progression of their condition, strengthening the doctor's and health team's relationship with the patients and their families. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.
A Proposed Activity for a Meaningful Learning about the Moon Phases. (Breton Title: Uma Proposta de Atividade Para a Aprendizagem Significativa sobre as Fases da Lua.) Una Actividad Propuesta Para EL Aprendizaje Significativo Acerca de Las Fases de la Luna
Martins, Bruno Andrade; Langhi, Rodolfo
ínua avaliação durante o processo, culmina com a elaboração de uma história em quadrinhos envolvendo as fases da Lua. Portanto, o objetivo deste trabalho é apresentar uma proposta de atividade didática diferenciada sustentada pelos princípios teóricos da aprendizagem significativa aplicada ao ensino das fases da Lua durante as aulas de Física no ensino médio. En este trabajo se presenta uno de los contenidos de la Astronomía y el evidente fracaso en la enseñanza del tema en la escuela secundaria, a pesar del hecho que los documentos oficiales apuntan para la necesidad de trabajar contenidos de Astronomía en este nivel. Entre los conceptos alternativos en Astronomía que los alumnos secundarios llevan consigo, aún después de terminados los estudios, destacamos aquí el fenómeno de las fases de la Luna. El desarrollo de diferentes estrategias en relación con los métodos tradicionales, dirigidas al proceso de enseñanza-aprendizaje en este tema fue considerado en este trabajo como uno de los resultados obtenidos a la luz de los referenciales del aprendizaje significativo, tal como fueron fundamentados por Ausubel. Según la propuesta que aquí se presenta, la participación activa de los estudiantes en la ejecución de una actividad experimental y otras actividades educativas destinadas a la evaluación continua durante el proceso culminó en la elaboración de una historieta respecto de las fases de la Luna. Por lo tanto, el objetivo de este trabajo es presentar una propuesta de actividad de enseñanza diferenciada con el apoyo de los principios teóricos del aprendizaje significativo aplicado a la enseñanza de las fases de la luna durante las clases de física del ciclo secundario.
Vélez, Yovanska Duarté; Dávila, Paloma Torres; Hernández, Samariz Laboy
Presentamos un estudio de caso de una adolescente puertorriqueña con comportamiento suicida. Esta comenzó una Terapia Socio Cognitivo-Conductual para el Comportamiento Suicida (TSCC-CS) de tipo ambulatorio luego de una hospitalización por intento suicida. La TSCC-CS incorpora una perspectiva ecológica y de desarrollo a la terapia cognitivo-conductual. Inicialmente mostró baja autoestima y severos síntomas depresivos y de ansiedad. Al finalizar el tratamiento, manifestó un cambio significativo en su sintomatología clínica y evidenció una mejoría en sus destrezas de manejo. No presentó ideas suicidas durante meses previos, ni durante el seguimiento. El análisis de este caso permitió realizar cambios en el protocolo de tratamiento, particularmente en las sesiones de familia y de comunicación con el fin de aumentar la viabilidad del tratamiento. PMID:26702337
Foldi, I; Gullan, P J
This study reviews the status of all Neotropical genera and species of Coelostomidiidae (Hemiptera: Coccoidea) and transfers them to the family Monophlebidae in the Cryptokermesini Foldi & Gullan tribe n. (the tribe Cryptokermini Tao & Hao is recognised here as a nomen nudum). This change of family placement for Neotropical taxa is based on the morphology of adult males, as supported by the phylogenetic study of Hodgson & Hardy (2013), and by unpublished DNA data. New diagnoses are provided for each of the four recognised genera of Cryptokermesini: Cryptokermes Hempel, Mimosicerya Cockerell, Neocoelostoma Hempel and Paracoelostoma Morrison. The genus Nautococcus Vayssière is considered here to be a junior synonym (syn. n.) of Mimosicerya and the type species of Nautococcus, N. schraderae Vayssière, thus becomes M. schraderae (Vayssière) comb. n. Cryptokermes mexicanus Morrison is transferred to Mimosicerya as M. mexicana (Morrison) comb. n. Also Cryptokermes mimosae Foldi does not fit the morphological concept of Cryptokermes and is excluded from this genus and revision, and from the new tribe; its taxonomic position is uncertain and requires further study. All type species of the Cryptokermesini, including N. schraderae (as M. schraderae), are redescribed and illustrated based on most female instars and available adult males, examined using optical and scanning electron microscopes. Adult males are described and illustrated only for M. schraderae and N. xerophila. Keys are provided to distinguish the Neotropical monophlebid tribes Cryptokermesini and Llaveiini and to recognise each cryptokermesine genus based on female instars and first-instar nymphs. The included species of Cryptokermesini and their known distributions are: Cryptokermes brasiliensis Hempel from Brazil and C. oaxaensis Foldi from Mexico; Mimosicerya hempeli (Cockerell) from Brazil, M. mexicana from Mexico, M. schraderae from Panama and M. williamsi Foldi from Venezuela; Neocoelostoma xerophila
Darroz, Luiz Marcelo; Heineck, Renato; Samudio Pérez, Carlos Ariel
In this report, the development of a methodological proposal which approaches basic concepts of astronomy-grounded pedagogically on Meaningful Learning is described. The proposal, which consists of four meetings, was developed by teachers and academics of the course of Professor in Physics of the University of Passo Fundo (UPF), through an extension course to a group of highschool students of a public school of the town of Passo Fundo, RS. The work was focused into basic concepts of astronomy. The signs of Meaningful Learning have been obtained by means of research and evaluation tools that were applied at the end of each meeting. The evaluation of the proposal has been conducted by means of a final questionnaire which was answered by the participants at the end ofthe development of activities. By means of the results obtained from the different instruments, and the comments made by the participants during the activities and by means of the high rates of approval obtained in the final questionnaire, we think that the proposal reached the established goals and it may be repeated with the certainty of success. En este relato se describe una propuesta de desarrollo metodológico que aborda conceptos básicos de astronomía fundamentada pedagógicamente en el Aprendizaje Significativo. La propuesta que comprende cuatro encuentros, fue desarrollada por profesores y académicos del curso de Licenciatura en Física de la Universidad de Passo Fundo (UPF), a través de un curso de extensión para un grupo de Liceo del 6º año de una Escuela Pública de la ciudad de Passo Fundo/RS. El trabajo tuvo como eje principal los "conceptos básicos de astronomía". Los indicios de Aprendizaje Significativo fueron obtenidos por instrumentos de pesquisa y evaluación, siempre aplicados después de cada encuentro. La evaluación de la propuesta fue hecha a través de un cuestionario final y contestado por los participantes al finalizar el desarrollo de actividades. Por los resultados
Huh, Ji Hye; Lim, Jung Soo; Lee, Mi Young; Chung, Choon Hee; Shin, Jang Yel
Few studies have reported the relationship between sarcopenia and the estimated amount of sodium excreted in 24 h, as measured by the spot urine test (E24UNA), in a community-dwelling cohort. We investigated the gender specific association between E24UNA values and body composition indices. Data from a total of 7162 participants (3545 men and 3617 postmenopausal women) aged 45 years or older were obtained from multiple Korea National Health and Nutrition Examination Surveys (2008-2010) and analyzed. The total amount of sodium excreted in the urine in a 24-h period was estimated with spot urine specimens. Sarcopenia was defined as an appendicular skeletal muscle mass divided by body weight (ASM/Wt) that was less than 1 standard deviation below the sex-specific mean for young adults. E24UNA values were positively correlated with body mass index, waist circumference, total fat mass, and blood pressure; in contrast, E24UNA values were negatively correlated with ASM/Wt in both sexes. Compared with those in the lowest E24UNA tertile, participants in the highest E24UNA tertile were at higher risk for sarcopenia (men: odds ratio (OR)=1.3 [95% confidence interval (CI)=1.07-1.59]; women: OR=1.41 [95% CI=1.16-1.73]). Further classification of subjects with sarcopenia into sarcopenic obese and sarcopenic nonobese groups revealed that the highest E24UNA values were found in the sarcopenic obese group; this difference was statistically significant. The next highest levels were found in the sarcopenic nonobese group, followed by the nonsarcopenic group. This trend was observed in both sexes. High E24UNA values were independently associated with both sarcopenia and obesity in Korean individuals older than 45 years. These results suggest that high salt intake may have a deleterious effect on body composition. Copyright © 2015. Published by Elsevier Inc.
La bronquiolitis obliterante es una enfermedad pulmonar crónica infrecuente y grave producto de una lesión del tracto respiratorio inferior. En nuestro país, es más frecuente observarla secundaria a una lesión viral grave, en especial, por adenovirus. La bronquiolitis obliterante se caracteriza por la oclusión parcial o total del lumen de los bronquiolos respiratorios y terminales por tejido inflamatorio y fibrosis, que produce la obstrucción crónica de la vía aérea. Este consenso discute el estado actual del conocimiento en las diferentes áreas de la bronquiolitis obliterante secundaria a una lesión infecciosa.
Pasternak, Anna; Hernandez, Frank J.; Rasmussen, Lars M.; Vester, Birte; Wengel, Jesper
A 15-mer DNA aptamer (named TBA) adopts a G-quadruplex structure that strongly inhibits fibrin-clot formation by binding to thrombin. We have performed thermodynamic analysis, binding affinity and biological activity studies of TBA variants modified by unlocked nucleic acid (UNA) monomers. UNA-U placed in position U3, U7 or U12 increases the thermodynamic stability of TBA by 0.15–0.50 kcal/mol. In contrast, modification of any position within the two G-quartet structural elements is unfavorable for quadruplex formation. The intramolecular folding of the quadruplexes is confirmed by Tm versus ln c analysis. Moreover, circular dichroism and thermal difference spectra of the modified TBAs displaying high thermodynamic stability show bands that are characteristic for antiparallel quadruplex formation. Surface plasmon resonance studies of the binding of the UNA-modified TBAs to thrombin show that a UNA monomer is allowed in many positions of the aptamer without significantly changing the thrombin-binding properties. The biological effect of a selection of the modified aptamers was tested by a thrombin time assay and showed that most of the UNA-modified TBAs possess anticoagulant properties, and that the construct with a UNA-U monomer in position 7 is a highly potent inhibitor of fibrin-clot formation. PMID:20870750
The Universe in a Box: Introduction to the Study of Astronomy in the Initial Formation of Physics Teachers. (Spanish Title: El Universo Representado en Una Caja: Introducción al Estudio de la Astronomía en la Formación Inicial de Profesores de Física.) O Universo Representado em Uma Caixa: Introdução ao Estudo da Astronomia NA Formação Inicial de Professores de Física
Longhini, Marcos Daniel
This is a report of an activity of introduction to the study of Astronomy developed with a group of future Physics teachers at a Brazilian public university. Such activity had the goal of giving privileged emphasis to notions of spatiality, alternative conceptions of the participants and the process of interaction among peers, and consisted of the representation, in a three dimensional space, of the models of the universe that the participants had. The results, which were categorized as miscellaneous, geocentric, heliocentric and acentric models of the universe, were qualitatively analyzed. Analyses of the activity in the perspective of the participants are indicated and additional considerations are made regarding its use as a resource for teaching Astronomy and for teacher training. Este es el informe de una actividad para presentar un estudio introductorio de la Astronomía, desarrollado con una clase de futuros profesores de física en una universidad pública brasileña. Esta actividad tuvo como objetivo centrar las nociones de espacialidad, las concepciones alternativas de los participantes y el proceso de interacción entre pares, y consistió en la representación en un espacio tridimensional, de los modelos del universo que los participantes habían. Los resultados, que se clasificaron en universo miscelania, geocéntrico, heliocéntrico y acentrico, se analizaron cualitativamente. Son identificadas análisis de la actividad por los participantes, e hizo observaciones sobre su uso como recurso para la enseñanza de la astronomía y la formación de docentes. Trata-se do relato de uma atividade de introdução ao estudo da Astronomia, desenvolvida com uma turma de futuros professores de Física, em uma universidade pública brasileira. Tal atividade teve como meta privilegiar noções de espacialidade, as concepções alternativas dos participantes e o processo de interação entre pares e constou da representação, em um espaço tridimensional, dos
...--Internal, of Chapter 5, Time Limits Maintenance Checks, of EMBRAER EMB145 Aircraft Maintenance Manual, Part...--Tail Cone Fairing--Internal, of Chapter 5, Time Limits Maintenance Checks, of EMBRAER EMB145 Aircraft... Maintenance Checks, of EMBRAER EMB145 Aircraft Maintenance Manual, Part II, AMM-145/1124, Revision 54, dated...
... lightning strikes from causing certain parts to contact the airplane pitch control system, which could... lightning strike effects [could cause certain parts to contact the airplane pitch control system, which... a lightning strike hitting an airplane tail boom causing certain rear bulkhead parts to jam an...
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... revising the Airworthiness Limitations Section (ALS) of the Instructions for Continued Airworthiness (ICA... cracks resulted in the manufacturer modifying the ALS of EMBRAER 170 Maintenance Review Board Report.... Analysis of these cracks resulted in modifications on the Airworthiness Limitation Section (ALS) of Embraer...
... revising the Airworthiness Limitations Section (ALS) of the Instructions for Continued Airworthiness (ICA... cracks resulted in manufacturer modifications of the ALS of Embraer ERJ 170 Maintenance Review Board... resulted in modifications on the Airworthiness Limitation Section (ALS) of Embraer ERJ 170 Maintenance...
NAHÓN SERFATY, Isaac; EID, Mahmoud
En el marco de un proyecto de investigación-acción que se implementó en Venezuela de 2009 a 2013 se buscó empoderar (empower) a activistas sociales y pacientes en la lucha contra el cáncer de mama (CM). Este proyecto se puso en marcha en un contexto de alta polarización política y social en el marco de la llamada «Revolución bolivariana». A partir de una perspectiva ecológica de la comunicación y el activismo en salud, que integra los niveles interpersonal, grupal y social, se celebraron una serie de actividades orientadas a desarrollar las habilidades de vocería de ciudadanos, especialmente de mujeres, y ampliar las redes de cooperación entre diversos sectores, al mismo tiempo que se perfiló una visión consensuada entre actores sociales e institucionales sobre una respuesta nacional contra el CM. Una comunicación horizontal y participativa permitió que se escuchara la voz de actores usualmente marginalizados en las políticas sanitarias. PMID:27867911
Martínez-Flores, Francisco; Sandoval-Zamora, Hugo; Machuca-Rodriguez, Catalina; Barrera-López, Araceli; García-Cavazos, Ricardo; Madinaveitia-Villanueva, Juan Antonio
Tissue storage is a medical process that is in the regulation and homogenisation phase in the scientific world. The international standards require the need to ensure safety and efficacy of human allografts such as skin and other tissues. The activities of skin and tissues banks currently involve their recovery, processing, storage and distribution, which are positively correlated with technological and scientific advances present in current biomedical sciences. A description is presented of the operational model of Skin and Tissue Bank at INR as successful case for procurement, recovery and preservation of skin and tissues for therapeutic uses, with high safety and biological quality. The essential and standard guidelines are presented as keystones for a tissue recovery program based on scientific evidence, and within an ethical and legal framework, as well as to propose a model for complete overview of the donation of tissues and organ programs in Mexico. Finally, it concludes with essential proposals for improving the efficacy of transplantation of organs and tissue programs. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.
Ruiz-Padilla, Alan Joel; Campos-Xolalpa, Nimsi; Carranza-Alvarez, Candy; Maldonado-Miranda, Juan Jose
The consumption of medicinal plants has notably increased over the past two decades. People consider herbal products as safe because of their natural origin, without taking into consideration whether these plants contain a toxic principle. This represents a serious health problem. A bibliographic search was carried out using published scientific material on native plants from Mexico, Central America, and the Caribbean, which describe the ethnobotanical and toxicological information of medicinal plants empirically considered to be toxic. A total of 216 medicinal plants belonging to 77 families have been reported as toxic. Of these plants, 76 had been studied, and 140 plants lacked studies regarding their toxicological effects. The toxicity of 16 plants species has been reported in clinical cases, particularly in children. From these plants, deaths have been reported with the consumption of Chenopodium ambrosioides, Argemone mexicana, and Thevetia peruviana. In most of the cases, the principle of the plant responsible for the toxicity is unknown. There is limited information about the toxicity of medicinal plants used in Mexico, Central America, and the Caribbean. More toxicological studies are necessary to contribute information about the safe use of the medicinal plants cited in this review. PMID:29234446
Ramírez, Juan David; Hernández, Carolina; León, Cielo M; Ayala, Martha S; Flórez, Carolina; González, Camila
Leishmaniases are tropical zoonotic diseases, caused by kinetoplastid parasites from the genus Leishmania. New World (NW) species are related to sylvatic cycles although urbanization processes have been reported in some South American Countries such as Colombia. Currently, few studies show the relative distribution of Leishmania species related to cutaneous Leishmaniasis (CL) in South America due to the lack of accurate surveillance and public health systems. Herein, we conducted a systematic estimation of the Leishmania species causing CL in Colombia from 1980 to 2001 via molecular typing and isoenzymes. A total of 327 Leishmania isolates from humans, sandflies and reservoirs were typed as L. panamensis 61.3% (201), L. braziliensis 27.1% (88), L. lainsoni 0.6% (2), L. guyanensis 0.9% (3), L. infantum chagasi 4% (12), L. equatoriensis 0.6% (2), L. mexicana 2.1% (8), L. amazonensis 2.8% (9) and L. colombiensis 0.6% (2). This is the first report of two new Leishmania species circulating in Colombia and suggests the need to convince the Colombian government about the need to deploy and standardize tools for the species identification to provide adequate management to individuals suffering this pathology.
Osho, A; Adetunji, T; Fayemi, S O; Moronkola, D O
The need for a reduction in drug resistance led to the investigation of Argemone Mexicana L. as an agent against Bacillus subtilis, Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, Candida stellatoidea and Candida torulopsis, using well diffusion and minimum inhibitory concentrations methods. The sensitivity of Bacillus Subtilis, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus to the essential oils of both the aerial and root parts were determined. Pseudomonas aeruginosa was resistant to the essential oil from both the aerial and root part of the plant. C. torulopsis, C. stellatoidea and C. albicans were susceptible to the essential oils from the aerial and root part of the plant. The minimum inhibitory concentrations ranging between 3.75 mg/ml and 4.0 mg/ml were recorded for Bacillus subtilis, Klebsiella pneumoniae by the aerial and the root extracts, but P. aeruginosa and S. aureus were not susceptible to the aerial and root extracts. The observed inhibition of selected bacteria and fungi by oils of Physalis angulata makes it a promising antimicrobial agent. This study justifies its uses for treatment of sores, cuts, intestinal and digestive problems and some skin-diseases often reported in folkloric medicine.
López-Zamudio, José; Ramírez-González, Luis Ricardo; Núñez-Márquez, Julia; Fuentes Orozco, Clotilde; González Ojeda, Alejandro; Leonher-Ruezga, Karla Lisseth
Gastric non-Hodgkin lymphoma is a rare tumour that represents approximately 7% of all stomach cancers and 2% of all lymphomas. The most frequent location of gastric MALT (mucosa associated lymphoid tissue) lymphomas is in the antrum in 41% of the cases, and 33% can be multifocal. The risk of spontaneous perforation of a gastric MALT lymphoma is 4-10%. 24 year old male patient carrying the Human Immunodeficiency Virus, who began with signs and symptoms of acute abdomen and fever 72 hours before arriving in the emergency room. A computed tomography was performed that showed free fluid in the cavity, and gastric wall thickening. The patient underwent a laparotomy, finding absence of the anterior wall of the stomach, sealed with the left lobe of the liver, colon and omentum. Total gastrectomy, with oesophagosty and jejunostomy tube, was performed. Gastric perforation secondary to a MALT lymphoma is rare, with high mortality. There is limited information reported of this complication and should be highly suspected in order to provide appropriate treatment for a complication of this type. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.
Mejía-Salas, Jesús Alberto; Sánchez-Corona, Hugo; Priego-Niño, Alejandro; Cárdenas-Rodríguez, Edgar; Sánchez-Galindo, José Antonio
Rhabdomyosarcoma is the most common sarcoma of soft tissues in childhood and adolescence, with an annual incidence of 4-7 cases per million children aged 15. Embryonal rhabdomyosarcoma is common in adults younger than 30 years, and are usually presented as a large painless, palpable mass (> 5cm). Survival in the case of paratesticular sarcoma in men is approximately 50%. Male 27 years of age with no history of importance, was seen in a clinic with an increased, painless, left testicular volume 3 years onset. Intrascrotal left testicle increased volume, with dimensions of 20×12×8cm, a stone and left inguinal node in induratum measuring 2×2cm. Microscopically, it showed a pattern of an embryonal rhabdomyosarcoma with left inguinal node metastases. Early diagnosis of testicular tumours, and especially of primary intratesticular rhabdomyosarcomas, and aggressive surgical treatment in combination with chemotherapy reduces the incidence of local recurrence and may improve the rate of disease-free survival and overall survival in adult patients with metastases. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.
Bender, L.C.; Li, H.; Thompson, B.C.; Morrow, P.C.; Valdez, R.
Exotic wildlife can introduce new diseases or act as reservoirs of endemic diseases. On White Sands Missile Range, New Mexico (USA), significant declines in populations of native ungulates generally correspond to increases in range and population density of the exotic gemsbok (Oryx gazella gazella), introduced beginning in 1969. We surveyed gemsbok in 2001 for exposure to a variety of diseases potentially important for native ungulates. High seroprevalence was found for malignant catarrhal fever virus (49 [98%] of 50 sera; 43 [96%] of 45 plasma samples), bluetongue virus (48 [96%] of 50), bovine respiratory syncytial virus (33 [66%] of 50), and parainfluenza-3 virus (10 [20%] of 50). Low numbers of Nematodirus spp. eggs in a few individuals were the only parasites detected in gemsbok. Exposure to the above diseases in gemsbok is of interest to managers because of potential implications for recovery of desert bighorn sheep (Ovis canadensis mexicana) and desert mule deer (Odocoileus hemionus crooki) in the White Sands area because each has been implicated in mortality in these species either in the White Sands area or elsewhere in the western/southwestern United States. ?? Wildlife Disease Association 2003.
Navas-Cuéllar, José Aurelio; Cañete-Gómez, Jesús; López-Bernal, Francisco; García-Rivera, Carla; Pareja-Ciuró, Felipe; Padillo-Ruiz, Javier
Splenic involvement secondary to blunt abdominal trauma is often treated by performing a splenectomy. The severity of the post-splenectomy syndrome is currently well known (blood loss, sepsis), so there is an increasing tendency to preserve the spleen. The case is presented of splenic preservation after blunt abdominal trauma with hilum involvement, emphasising the role of Floseal as a haemostatic agent, as well as the use of resorbable meshes to preserve the spleen. A 22-year-old woman presenting with a grade IV splenic lesion secondary to a blunt abdominal trauma after a traffic accident. Partial splenic resection was performed and bleeding was controlled with Floseal and use of a reinforcing polyglycolic acid mesh. No postoperative complications occurred, being discharged on day 5. The long-term follow-up has been uneventful. The use of haemostatic agents such as thrombin and the gelatine gel (FloSeal) and the use of polyglycolic acid meshes enable spleen-preserving surgery, making it a feasible and reproducible procedure and an alternative to classical splenectomy. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.
Hu, Qing-bi; He, Yu; Zhou, Xun
Species included in the Sporothrix schenckii complex are temperature-dependent with dimorphic growth and cause sporotrichosis that is characterized by chronic and fatal lymphocutaneous lesions. The putative species included in the Sporothrix complex are S. brasiliensis, S. globosa, S. mexicana, S. pallida, S. schenckii, and S. lurei. S. globosa is the causal agent of sporotrichosis in China, and its pathogenicity appears to be closely related to the dimorphic transition, i.e. from the mycelial to the yeast phase, it adapts to changing environmental conditions. To determine the molecular mechanisms of the switching process that mediates the dimorphic transition of S. globosa, suppression subtractive hybridization (SSH) was used to prepare a complementary DNA (cDNA) subtraction library from the yeast and mycelial phases. Bioinformatics analysis was performed to profile the relationship between differently expressed genes and the dimorphic transition. Two genes that were expressed at higher levels by the yeast form were selected, and their differential expression levels were verified using a quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR). It is believed that these differently expressed genes are involved in the pathogenesis of S. globosa infection in China. PMID:26642182
de Sousa Araújo, Pedro Soares; de Oliveira, Simone Santiago Carvalho; d'Avila-Levy, Claudia Masini; Dos Santos, André Luis Souza; Branquinha, Marta Helena
Despite the available drug options, leishmaniasis treatment remains unsatisfactory. The repurposing of calpain inhibitors originally developed for human diseases became an interesting alternative, since Leishmania cells express calpain-related proteins. The susceptibility of six Leishmania species (L. amazonensis, L. braziliensis, L. major, L. mexicana, L. chagasi, and L. donovani) to the calpain inhibitor MDL28170 was determined. Promastigote and intracellular amastigote viability in the presence of MDL28170 was evaluated. MDL28170 was able to reduce promastigote proliferation in a dose-dependent manner for all the parasites. A significant reduction on the general parasite metabolism was detected, as judged by resazurin assay, as well as induced important morphological alterations, including rounding promastigotes and loss of the flagellum. MDL28170 was also able to reduce the number of intracellular amastigotes in RAW macrophages. The susceptibility of both parasite stages (promastigotes and amastigotes) to MDL28170 was similar for all Leishmania species tested. MDL28170 showed a much higher toxicity to Leishmania amastigotes when compared with mammalian macrophages, displaying selectivity index values varying from 13.1 to 39.8. These results suggest that the development of calpain inhibitors may represent an interesting alternative in the treatment of leishmaniasis.
Manin, Aurelie; Corona-M, Eduardo; Alexander, Michelle; Craig, Abigail; Thornton, Erin Kennedy; Yang, Dongya Y; Richards, Michael; Speller, Camilla F
The turkey ( Meleagris gallopavo ) represents one of the few domestic animals of the New World. While current research points to distinct domestication centres in the Southwest USA and Mesoamerica, several questions regarding the number of progenitor populations, and the timing and intensity of turkey husbandry remain unanswered. This study applied ancient mitochondrial DNA and stable isotope ( δ 13 C, δ 15 N) analysis to 55 archaeological turkey remains from Mexico to investigate pre-contact turkey exploitation in Mesoamerica. Three different (sub)species of turkeys were identified in the archaeological record ( M. g. mexicana , M. g. gallopavo and M. ocellata ), indicating the exploitation of diverse local populations, as well as the trade of captively reared birds into the Maya area. No evidence of shared maternal haplotypes was observed between Mesoamerica and the Southwest USA, in contrast with archaeological evidence for trade of other domestic products. Isotopic analysis indicates a range of feeding behaviours in ancient Mesoamerican turkeys, including wild foraging, human provisioning and mixed feeding ecologies. This variability in turkey diet decreases through time, with archaeological, genetic and isotopic evidence all pointing to the intensification of domestic turkey management and husbandry, culminating in the Postclassic period.
Lasa, J S; Olivera, P; Soifer, L; Moore, R
There is a wide heterogeneity in the reports of celiac disease prevalence in iron-deficiency anemia patients. To determine the prevalence of celiac disease in patients with iron-deficiency anemia. Adult patients with a diagnosis of iron-deficiency anemia were enrolled for upper endoscopy with duodenal biopsies. Healthy volunteers that underwent upper endoscopy were enrolled as controls. A total of 135 patients with iron-deficiency anemia and 133 controls were enrolled. Celiac disease prevalence was higher in the iron-deficiency anemia group [11.11 vs. 1.51%, OR: 8.18 (1.83-36.55), P=.001). Of the celiac disease patients in the iron-deficiency anemia group, 73.3% had at least one endoscopic sign suggesting villous atrophy, whereas 100% of the celiac disease patients in the control group presented with at least one endoscopic sign. Patients with iron-deficiency anemia have an increased risk for celiac disease. Up to 25% of these patients may not present any endoscopic sign suggesting villous atrophy. Copyright © 2017 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.
Hinojosa, Carlos A; Anaya-Ayala, Javier E; Boyer-Duck, Estefanía; Laparra-Escareno, Hugo; Torres-Machorro, Adriana; Lizola, Rene
Nutcracker syndrome is a rare entity, and in the majority of cases is the result of extrinsic compression of the left renal vein between the superior mesenteric artery and the aorta, associated with functional stenosis. To present the case of a 19-year-old female with no significant medical history with confirmed diagnosed of nutcracker syndrome treated successfully by endovascular means. She was referred to the Vascular Surgery Department with a 6-month history of macroscopic haematuria, after other aetiologies were ruled out. Abdominal computed tomography angiography revealed compression of the left renal vein; the patient underwent endovascular treatment, and a 12×16 mm balloon expandable stent was placed with immediate angiographic improvement, decreased pressure gradients and progressive resolution of haematuria. At one year, she remains symptom-free. Nutcracker syndrome is uncommon, and a high index of suspicion is needed. Macroscopic haematuria is not always present, and in our case stent placement demonstrated effectiveness in the resolution of symptoms at 12 months' follow--up. We also present a brief review of the literature. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.
Ramírez, Juan David; Hernández, Carolina; León, Cielo M.; Ayala, Martha S.; Flórez, Carolina; González, Camila
Leishmaniases are tropical zoonotic diseases, caused by kinetoplastid parasites from the genus Leishmania. New World (NW) species are related to sylvatic cycles although urbanization processes have been reported in some South American Countries such as Colombia. Currently, few studies show the relative distribution of Leishmania species related to cutaneous Leishmaniasis (CL) in South America due to the lack of accurate surveillance and public health systems. Herein, we conducted a systematic estimation of the Leishmania species causing CL in Colombia from 1980 to 2001 via molecular typing and isoenzymes. A total of 327 Leishmania isolates from humans, sandflies and reservoirs were typed as L. panamensis 61.3% (201), L. braziliensis 27.1% (88), L. lainsoni 0.6% (2), L. guyanensis 0.9% (3), L. infantum chagasi 4% (12), L. equatoriensis 0.6% (2), L. mexicana 2.1% (8), L. amazonensis 2.8% (9) and L. colombiensis 0.6% (2). This is the first report of two new Leishmania species circulating in Colombia and suggests the need to convince the Colombian government about the need to deploy and standardize tools for the species identification to provide adequate management to individuals suffering this pathology. PMID:27328969
Fair, Jeanne M; Myers, Orrin B
Eggshell quality, clutch size, sex ratio, and hatching success of western bluebirds (Sialia mexicana) and ash-throated flycatchers (Myiarchus cinerascens) were studied on a landscape-soil contaminant gradient at Los Alamos National Laboratory (LANL) in New Mexico from 1997 to 1999. A variety of contaminants (heavy metals, chemicals, insecticides, polychlorinated biphenyls (PCBs), organochlorines, and radioactive isotopes) range across different spatial scales and concentrations on LANL land. This study is an example of a monitoring program over a large area with varying degree of contamination that is used to highlight locations of concern for future research. There were two locations where the flycatcher had a lower hatching success. The bluebirds at Sandia wetland, a location of concern for PCBs. had a thinner eggshell thickness index (RATCLIFFE) and the eggs were smaller than at other locations. The flycatcher had thinner eggshells than bluebirds, which could add to sensitivity to exposure to contaminants. There was no variation in clutch size or sex ratio between locations or areas closer to contaminant release sites for both species. Percent females in the clutch ranged from 0 to 100% in the WEBL and from 33 to 67% for ATFL.
van Thiel, P P A M; Zeegelaar, J E; van Gool, T; Faber, W R; Kager, P A
Skin lesions occur frequently in travelers to tropical countries. Military personnel acquire skin lesions regularly during jungle training as did Dutch troops who trained in the jungle of Belize in 1998, 2004 and 2009, in an area endemic for cutaneous leishmaniasis. Demographic and clinical data were collected retrospectively. Diagnostic investigations for cutaneous leishmaniasis included Giemsa stain, culture, PCR and NASBA and histopathology of biopsies. Treatment of leishmaniasis was with sodium stibogluconate, given intravenously or intralesionally, the latter with cryotherapy. In 1998 and 2004 cutaneous leishmaniasis due to Leishmania braziliensis and Leishmania mexicana infection was diagnosed in 25 persons out of 99 (attack rate 25.2%) and 14 persons out of 80 (attack rate 17.5%) respectively. In 2009 cutaneous leishmaniasis was not acquired. Skin problems were common during and after jungle training. Cutaneous leishmaniasis was important in the first two cohorts but not observed in the third cohort. Factors that could have played a role in the absence of cutaneous leishmaniasis in the third cohort include variability in transmission and availability of better preventive measures and adherence to these. Sodium stibogluconate treatment, intralesional or intravenous, was effective. Copyright © 2011 Elsevier Ltd. All rights reserved.
Becerril, Marco A; Angeles-Pérez, Vidal; Noguez-García, Julio Cr; Imbert-Palafox, José L
In order to determine the risk of transmission of Trypanosoma cruzi by triatomines in Metztitlan municipality, Hidalgo State, Mexico, entomological indexes were calculated and the characteristics of dwellings were described. A transversal, retrospective, descriptive, and observational study was performed by means of an intentional not probabilistic and expertise sampling from January to December of 2005 in 10 localities in which presence of triatomines were investigated either intra or peridomestic environmental in 699 houses. Building material and presence of infected triatomines with T. cruzi were registered to determine entomologic indexes. The triatomine species collected were: Triatoma barberi (Usinger) and T. mexicana (Herrich-Schaeffer) (Hemiptera: Reduviidae). The results indicated that natural infection index varied from 7.7% to 50%; colonization index reached 80%; infestation index varied from 7.7% to 25%; dispersion index was 70%. Stone-walled houses were more infested. We can conclude that it is necessary to establish T. cruzi transmission control measures against triatomines in localities from Metztitlan, primarily in stone-walled houses where T. barberi occurs, as it was the most important vector species in the transmission of T. cruzi in this municipality.
Isla Ortiz, David; Montalvo-Esquivel, Gonzalo; Chanona-Vilchis, José Gregorio; Herrera Gómez, Ángel; Ñamendys Silva, Silvio Antonio; Pareja Franco, Luis René
Radical hysterectomy is the standard treatment for patients with early-stage cervical cancer. However, for women who wish to preserve fertility, radical trachelectomy is a safe and viable option. To present the first case of laparoscopic radical trachelectomy performed in the National Cancer Institute, and published in Mexico. Patient, 34 years old, gravid 1, caesarean 1, stage IB1 cervical cancer, squamous, wishing to preserve fertility. She underwent a laparoscopic radical trachelectomy and bilateral dissection of the pelvic lymph nodes. Operation time was 330minutes, and the estimated blood loss was 100ml. There were no intraoperative or postoperative complications. The final pathology reported a tumour of 15mm with infiltration of 7mm, surgical margins without injury, and pelvic nodes without tumour. After a 12 month follow-up, the patient is having regular periods, but has not yet tried to get pregnant. No evidence of recurrence. Laparoscopic radical trachelectomy and bilateral pelvic lymphadenectomy is a safe alternative in young patients who wish to preserve fertility with early stage cervical cancer. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.
Rojas Pérez-Ezquerra, Beatriz; Guardia-Dodorico, Lorena; Arribas-Marco, Teresa; Ania-Lahuerta, Aldonza; González Ballano, Isabel; Chipana-Salinas, Margot; Carazo-Hernández, Belén
Abdominal wall Actinomycosis is a rare disease associated with the use of intrauterine device and as a complication of abdominal surgery. Diagnosis is difficult because it is unusual and behaves like a malignant neoplasm. A case report is presented of a patient who had used an intrauterine device for four years and developed a stony tumour in the abdominal wall associated with a set of symptoms that, clinically and radiologically, was simulating a peritoneal carcinomatosis associated with paraneoplastic syndrome, even in the course of an exploratory laparotomy. The patient attended our hospital with a two-month history of abdominal pain and symptoms that mimic a paraneoplastic syndrome. The diagnosis of abdominal actinomycosis was suspected by the finding of the microorganism in cervical cytology together with other cultures and Actinomyces negative in pathological studies, confirming the suspicion of a complete cure with empirical treatment with penicillin. Actinomycosis should be considered in patients with pelvic mass or abdominal wall mass that mimics a malignancy. Antibiotic therapy is the first treatment choice and makes a more invasive surgical management unnecessary. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.
Pritchard, Kyle R.; Hagar, Joan; Shaw, David C.
Mistletoes are parasitic or hemi-parasitic flowering plants that parasitize woody plants around the globe. Important food and cover resources provided by mistletoes have been related to strong patterns of positive association between wildlife diversity and mistletoe density. Mistletoes also create microhabitat features known to be important to wildlife by causing deformations in their host trees. However, links between availability of mistletoe-formed microhabitat and wildlife diversity has not been well studied. We investigated this relationship by quantifying microhabitat features and avian abundance and diversity related to infection by Oak Mistletoe (Phoradendron villosum) in Oregon White Oak (Quercus garryana). Q. garryana woodlands support several avian species of conservation concern, so an understanding of the influence of mistletoe on wildlife habitat is critical. Our results suggest that 1) structural heterogeneity within tree crowns; 2) avian species richness and abundance are positively associated with mistletoe load; and 3) P. villosum fruit, available is an important food for western bluebird (Sialia mexicana) and other wildlife in late autumn and early winter. If a goal of restoration is to maintain habitat for oak-associated bird species, managers should consider the retention of some oaks hosting mistletoe.
Lechner, Horst; Soriano, Pablo; Poschner, Roman; Hailes, Helen C; Ward, John M; Kroutil, Wolfgang
Norcoclaurine synthases (NCS), catalyzing a Pictet-Spengler reaction in plants as one of the first enzymes in the biosynthetic benzylisoquinoline pathway, are investigated for biocatalytic transformations. The library of NCS available is extended by two novel NCSs from Argemone mexicana (AmNCS1, AmNCS2) and one new NCS from Corydalis saxicola (CsNCS); furthermore, it is shown that the NCS from Papaver bracteatum (PbNCS) is a highly productive catalyst leading to the isoquinoline product with up to >99% e.e. Under certain conditions lyophilized whole Escherichia coli cells containing the various overexpressed NCS turned out to be suitable catalysts. The reaction using dopamine as substrate bears several challenges such as the spontaneous non-stereoselective background reaction and side reactions. The PbNCS enzyme is successfully immobilized on various carriers whereby EziG3 proved to be the best suited for biotransformations. Dopamine showed limited stability in solution resulting in the coating of the catalyst over time, which could be solved by the addition of ascorbic acid (e.g., 1 mg ml -1 ) as antioxidant. © 2017 The Authors. Biotechnology Journal Published by Wiley-VCH Verlag GmbH &Co. KGaA.
Manin, Aurelie; Corona-M, Eduardo; Craig, Abigail; Thornton, Erin Kennedy; Yang, Dongya Y.; Richards, Michael
The turkey (Meleagris gallopavo) represents one of the few domestic animals of the New World. While current research points to distinct domestication centres in the Southwest USA and Mesoamerica, several questions regarding the number of progenitor populations, and the timing and intensity of turkey husbandry remain unanswered. This study applied ancient mitochondrial DNA and stable isotope (δ13C, δ15N) analysis to 55 archaeological turkey remains from Mexico to investigate pre-contact turkey exploitation in Mesoamerica. Three different (sub)species of turkeys were identified in the archaeological record (M. g. mexicana, M. g. gallopavo and M. ocellata), indicating the exploitation of diverse local populations, as well as the trade of captively reared birds into the Maya area. No evidence of shared maternal haplotypes was observed between Mesoamerica and the Southwest USA, in contrast with archaeological evidence for trade of other domestic products. Isotopic analysis indicates a range of feeding behaviours in ancient Mesoamerican turkeys, including wild foraging, human provisioning and mixed feeding ecologies. This variability in turkey diet decreases through time, with archaeological, genetic and isotopic evidence all pointing to the intensification of domestic turkey management and husbandry, culminating in the Postclassic period. PMID:29410864
Sánchez-Forgach, Ernesto Roberto; Carpinteyro-Espín, Ubaldo; Alemán-Áviles, Jorge Alberto; Sánchez-Basurto, Carlos
In recent years, advances in molecular biology have resulted in innovations in breast cancer diagnostics and therapeutics. The development of genomics has revolutionized our understanding of this disease. MammaPrint ® was developed as a diagnostic tool to predict risk of breast cancer recurrence using the expression of 70 genes altering the clinicopathologic paradigm of selection of patients for adjuvant cytotoxic chemotherapy. A study of stage i-ii breast cancer patients on whom the MammaPrint ® genomic assay was performed. The use of the MammaPrint ® assay was a decisive factor for the recommendation of adjuvant treatment with chemotherapy and/or hormone therapy in patients with high risk for relapse. In our group, the patients with low-risk have not presented local or systemic recurrences DISCUSSION: The determination of the genetic characteristics and its alterations in breast cancer, is fundamentally important for a better identification of risk, as well as a better selection of cancer therapy. MammaPrint ® is an effective study to determine risk of recurrence of in early stage breast cancer. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.
Tara Luna; Thomas D. Landis; R. Kasten Dumroese
La elecciÃ³n del contenedor es una de las consideraciones mÃ¡s importantes al establecer un nuevo vivero o empezar a producir una especie nueva. El tipo y tamaÃ±o de contenedor no sÃ³lo determina la cantidad de agua y nutrientes minerales que estÃ¡n disponibles para el crecimiento de una planta, sino que tambiÃ©n afecta otros aspectos operativos del vivero, como el tamaÃ±o de...