Exploring research on ecotechnology through artificial intelligence and bibliometric maps.

Ecotechnology, quintessential for crafting sustainable socio-environmental strategies, remains tantalizingly uncharted. Our analysis, steered by the nuances of machine learning and augmented by bibliometric insights, delineates the expansive terrain of this domain, elucidates pivotal research themes and conundrums, and discerns the vanguard nations in this field. Furthermore, we deftly connect our discoveries to the United Nations' 2030 Sustainable Development Goals, thereby accentuating the profound societal ramifications of ecotechnology.

Impacts of leaks and gas accumulation on closed chamber methods for measuring methane and carbon dioxide fluxes from tree stems.

Accurate measurements of methane (CH4) and carbon dioxide (CO2) fluxes from tree stems are important for understanding greenhouse gas emissions. Closed chamber methods are commonly employed for this purpose; however, leaks between the chamber and the atmosphere as well as gas accumulation, known as the concentration buildup effect, can impact flux measurements significantly. In this study, we investigated the impacts of concentration buildup and leaks on semi-rigid closed chamber methods. Field measurements were conducted on six tree species, including three species from a Mexican mangrove ecosystem and three species from a Magellanic sub-Antarctic forest. Systematic observations revealed significant leak flow rates, ranging from 0.00 to 465 L h-1, with a median value of 1.25 ± 75.67 L h-1. We tested the efficacy of using cement to reduce leaks, achieving a leak flow rate reduction of 46-98 % without complete elimination. Our study also demonstrates a clear and substantial impact of concentration buildup on CH4 flux measurements, while CO2 flux measurements were relatively less affected across all tree species studied. Our results show that the combined effects of leaks and concentration buildup can lead to an underestimation of CH4 emissions by an average of 40 ± 20 % and CO2 emissions by 22 ± 22 %, depending on the bark roughness. Based on these findings, we recall a straightforward yet effective method to minimize experimental errors associated with these phenomena, previously established, and reiterated in the current context, for calculating emissions that considers effects of leaks and concentration buildup, while eliminating the need for separate determinations of these phenomena. Overall, the results, combined with a literature review, suggest that our current estimates of GHG flux from tree stems are currently underestimated.

Lead tolerance of Laguncularia racemosa is associated to high proline accumulation and high antioxidant capacities.

Mangrove forests are threatened by the continuous discharge of inorganic pollutants and studies show that coasts receive high levels of heavy metals, from which lead (Pb) is one of the most persistent and toxic. In the present study, lead accumulation capacity, as well as its toxicological effects and tolerance mechanisms, such as proline accumulation and increased antioxidant capacity were evaluated in two contrasting mangrove species: Avicennia germinans and Laguncularia racemosa. Six-month-old plants were exposed to different concentrations of lead nitrate (0, 75, 150, and 300 µM) and samples of roots and leaves were taken from all treatments at different times during a 30d exposure period. Both species accumulated Pb in their tissues mainly in the roots, but L. racemosa had a greater capacity to accumulate Pb than A. germinans. Nevertheless, lead exposure caused less leaf chlorosis, lower reduction in the efficiency of photosystem II, lower reduction of daily photosynthetic rates, and lower electrolyte leakage in L. racemosa than in A. germinans. In line with those results, L. racemosa, in response to Pb exposure, accumulated more proline and showed higher antioxidant capacity than A. germinans, in both roots and leaves. Altogether, L. racemosa might be more suitable for restoration purposes, as it is not only capable of accumulating more Pb in its tissues but also shows greater tolerance to the stress caused by lead.

CAM plants: their importance in epiphyte communities and prospects with global change.

BACKGROUND AND SCOPE: The epiphytic life form characterizes almost 10 % of all vascular plants. Defined by structural dependence throughout their life and their non-parasitic relationship with the host, the term epiphyte describes a heterogeneous and taxonomically diverse group of plants. This article reviews the importance of crassulacean acid metabolism (CAM) among epiphytes in current climatic conditions and explores the prospects under global change. RESULTS AND CONCLUSIONS: We question the view of a disproportionate importance of CAM among epiphytes and its role as a 'key innovation' for epiphytism but do identify ecological conditions in which epiphytic existence seems to be contingent on the presence of this photosynthetic pathway. Possibly divergent responses of CAM and C3 epiphytes to future changes in climate and land use are discussed with the help of experimental evidence, current distributional patterns and the results of several long-term descriptive community studies. The results and their interpretation aim to stimulate a fruitful discussion on the role of CAM in epiphytes in current climatic conditions and in altered climatic conditions in the future.

New Proposal of Epiphytic Bromeliaceae Functional Groups to Include Nebulophytes and Shallow Tanks.

The Bromeliaceae family has been used as a model to study adaptive radiation due to its terrestrial, epilithic, and epiphytic habits with wide morpho-physiological variation. Functional groups described by Pittendrigh in 1948 have been an integral part of ecophysiological studies. In the current study, we revisited the functional groups of epiphytic bromeliads using a 204 species trait database sampled throughout the Americas. Our objective was to define epiphytic functional groups within bromeliads based on unsupervised classification, including species from the dry to the wet end of the Neotropics. We performed a hierarchical cluster analysis with 16 functional traits and a discriminant analysis, to test for the separation between these groups. Herbarium records were used to map species distributions and to analyze the climate and ecosystems inhabited. The clustering supported five groups, C3 tank and CAM tank bromeliads with deep tanks, while the atmospheric group (according to Pittendrigh) was divided into nebulophytes, bromeliads with shallow tanks, and bromeliads with pseudobulbs. The two former groups showed distinct traits related to resource (water) acquisition, such as fog (nebulophytes) and dew (shallow tanks). We discuss how the functional traits relate to the ecosystems inhabited and the relevance of acknowledging the new functional groups.

Self-Organizing Maps to Multidimensionally Characterize Physical Profiles in Older Adults.

The aim of this study is to automatically analyze, characterize and classify physical performance and body composition data of a cohort of Mexican community-dwelling older adults. Self-organizing maps (SOM) were used to identify similar profiles in 562 older adults living in Mexico City that participated in this study. Data regarding demographics, geriatric syndromes, comorbidities, physical performance, and body composition were obtained. The sample was divided by sex, and the multidimensional analysis included age, gait speed over height, grip strength over body mass index, one-legged stance, lean appendicular mass percentage, and fat percentage. Using the SOM neural network, seven profile types for older men and women were identified. This analysis provided maps depicting a set of clusters qualitatively characterizing groups of older adults that share similar profiles of body composition and physical performance. The SOM neural network proved to be a useful tool for analyzing multidimensional health care data and facilitating its interpretability. It provided a visual representation of the non-linear relationship between physical performance and body composition variables, as well as the identification of seven characteristic profiles in this cohort.

Copper accumulation in the aquatic fern Salvinia minima causes more severe physiological stress than zinc.

Copper (Cu) and zinc (Zn) have a high demand in the industry. However, these ions, at high concentrations, can cause severe damage to both fauna and flora. Phytoremediation has gained international importance because its relatively low cost and it is environmentally friendly. The aim of the present study was to evaluate the capacity of Salvinia minima of accumulating Cu and Zn from aqueous solutions of various external concentrations (20, 40 and 80 µmol L-1 of CuSO4 and ZnSO4, separately). In addition, to estimate the effect of exposure of S. minima plants to those metals, on various physiological parameters (growth potential, maximum quantum efficiency of PSII, electrolyte leakage: as a cell membrane integrity index). S. minima was able of accumulating more Zn than Cu in its tissues, reaching values of 6.96 mg Cu g-1 dry weight (DW) and 19.6 mg Zn g-1 DW when exposed to 80 µM of each metal during 96 h, that were stored mainly at roots. Despite accumulating less Cu in its tissues, Cu had more severe reductions in various physiological parameters than Zn (in maximum quantum efficiency, integrity of cell membranes, and growth). We conclude that this species can be useful in the phytoremediation for copper and zinc in relatively short time, as maximum accumulation occurred within the first 24 h. However, in the long term, the accumulation of such metals is accompanied by a negative impact in the appearance, physiology, and growth of this plant species, which was more severe for copper exposure than for zinc.

Multidimensional tropical forest recovery.

Tropical forests disappear rapidly because of deforestation, yet they have the potential to regrow naturally on abandoned lands. We analyze how 12 forest attributes recover during secondary succession and how their recovery is interrelated using 77 sites across the tropics. Tropical forests are highly resilient to low-intensity land use; after 20 years, forest attributes attain 78% (33 to 100%) of their old-growth values. Recovery to 90% of old-growth values is fastest for soil (<1 decade) and plant functioning (<2.5 decades), intermediate for structure and species diversity (2.5 to 6 decades), and slowest for biomass and species composition (>12 decades). Network analysis shows three independent clusters of attribute recovery, related to structure, species diversity, and species composition. Secondary forests should be embraced as a low-cost, natural solution for ecosystem restoration, climate change mitigation, and biodiversity conservation.

Functional recovery of secondary tropical forests.

One-third of all Neotropical forests are secondary forests that regrow naturally after agricultural use through secondary succession. We need to understand better how and why succession varies across environmental gradients and broad geographic scales. Here, we analyze functional recovery using community data on seven plant characteristics (traits) of 1,016 forest plots from 30 chronosequence sites across the Neotropics. By analyzing communities in terms of their traits, we enhance understanding of the mechanisms of succession, assess ecosystem recovery, and use these insights to propose successful forest restoration strategies. Wet and dry forests diverged markedly for several traits that increase growth rate in wet forests but come at the expense of reduced drought tolerance, delay, or avoidance, which is important in seasonally dry forests. Dry and wet forests showed different successional pathways for several traits. In dry forests, species turnover is driven by drought tolerance traits that are important early in succession and in wet forests by shade tolerance traits that are important later in succession. In both forests, deciduous and compound-leaved trees decreased with forest age, probably because microclimatic conditions became less hot and dry. Our results suggest that climatic water availability drives functional recovery by influencing the start and trajectory of succession, resulting in a convergence of community trait values with forest age when vegetation cover builds up. Within plots, the range in functional trait values increased with age. Based on the observed successional trait changes, we indicate the consequences for carbon and nutrient cycling and propose an ecologically sound strategy to improve forest restoration success.

Cytomegalovirus Pulmonary Involvement in an Immunocompetent Adult.

INTRODUCTION: Cytomegalovirus (CMV) is a linear double-stranded DNA virus that may cause severe and potentially fatal infection in immunocompromised hosts. In immunocompetent individuals, the infection is typically mild or asymptomatic. However, in the last years, some cases of severe cytomegalovirus infection in immunocompetent individuals have been described. Clinical Presentation. The authors present a male patient aged 42 years, without specific medical history, who presented a 15-day history of fever, headache, night sweats, odynophagia, and bilateral otalgia, without improvement after four days of therapy with amoxicillin/clavulanic acid. Blood count and biochemistry were performed with liver cytolysis pattern. Chest teleradiography showed diffuse interstitial infiltrate. Thoracic CT scan revealed areas in a ground glass with a cross-linking component in the left and right upper lung lobes compatible with an inflammatory/infectious process. Blood serology was positive for CMV IgG and IgM. The detection on blood and bronchoalveolar lavage of CMV DNA by polymerase chain reaction (PCR) was also positive. Ganciclovir was started based on the clinical features and the result of CMV serology. After 48 hours, there was a significant clinical improvement, with remission of fever, and he was discharged on the 13th day of hospitalization with oral valganciclovir, completing a 21-day antiviral course at home. CONCLUSION: With this clinical case, the authors highlight the importance of considering CMV infection in evaluating patients with pneumonia, even in immunocompetent ones, particularly in those with no clinical improvement with antibiotics instituted for bacterial pneumonia, and when other causes have been ruled out.

El Niño-Southern Oscillation affects the water relations of tree species in the Yucatan Peninsula, Mexico.

We evaluated the effect of ENSO 2015/16 on the water relations of eight tree species in seasonally dry tropical forests of the Yucatan Peninsula, Mexico. The functional traits: wood density, relative water content in wood, xylem water potential and specific leaf area were recorded during the rainy season and compared in three consecutive years: 2015 (pre-ENSO conditions), 2016 (ENSO conditions) and 2017 (post-ENSO conditions). We analyzed tree size on the capacity to respond to water deficit, considering young and mature trees, and if this response is distinctive in species with different leaf patterns in seasonally dry tropical forests distributed along a precipitation gradient (700-1200 mm year-1). These traits showed a strong decrease in all species in response to water stress in 2016, mainly in the driest site. Deciduous species had lower wood density, higher predawn water potential and higher specific leaf area than evergreen species. In all cases, mature trees were more tolerant to drought. In the driest site, there was a significant reduction in water status, regardless of their leaf phenology, indicating that seasonally dry tropical forests are highly vulnerable to ENSO. Vulnerability of deciduous species is intensified in the driest areas and in the youngest trees.

National Cancer Institute scientific production scientometric analysis.

INTRODUCTION: Scientometrics analyzes scientific publications through bibliometric and computational techniques, whereby productivity and impact indicators are generated. OBJECTIVE: To propose a multidimensional methodology in order to obtain the scientometric profile of the National Cancer Institute (INCan), Mexico, and rank it with regard to other national health institutions. METHOD: Using the LabSOM software and the ViBlioSOM methodology based on artificial neural networks, the INCan scientific production indexed in the Web of Science from 2007 to 2017 was analyzed. The multidimensional scientometric profile of the Institute was obtained and compared with that of other national health institutions. RESULTS: In terms of productivity, INCan ranks fourth among the 10 Mexican public health institutions indexed in the Web of Science; in the normalized impact ranking, it ranks sixth. Although out of 1323 articles 683 (51.62 %) did not receive citations, 11 articles classified as excellent (0.83 %) obtained 24 % of 11,932 citations and, consequently, INCan normalized impact rate showed a mean productivity higher than the world mean. CONCLUSION: Multidimensional analysis with the proposed neural network enables obtaining a more reliable and comprehensive absolute and relative institutional scientiometric profile than that derived from measuring isolated variables.

INTRODUCCIÓN: La cienciometría permite analizar la productividad e impacto de las publicaciones científicas mediante técnicas bibliométricas y computacionales. OBJETIVO: Proponer una metodología multidimensional para obtener el perfil cienciométrico del Instituto Nacional de Cancerología (INCan), México, y compararlo respecto a otras instituciones nacionales de salud. MÉTODO: Con el programa LabSOM y la metodología ViBlioSOM, basada en redes neuronales artificiales, se analizó la producción científica del INCan indexada en la Web of Science entre 2007 y 2017. Se obtuvo el perfil cienciométrico multidimensional del Instituto y se comparó con el de otras instituciones nacionales de salud. RESULTADOS: En productividad, el INCan ocupa el cuarto lugar de las 10 instituciones mexicanas de salud pública indexadas en la Web of Science.; en el ranking de impacto normalizado, el sexto lugar. Aun cuando de 1323 artículos, 683 (51.62 %) no recibieron citas, 11 artículos de excelencia (0.83 %) lograron 24 % de 11 932 citas y, consecuentemente, el impacto normalizado del INCan evidenció una productividad media por arriba de la media mundial. CONCLUSIÓN: El análisis multidimensional con la red neuronal propuesta permite obtener un perfil cienciométrico institucional absoluto y relativo más fidedigno e integral que el derivado de conteos de variables aisladas.

Análisis cienciométrico de la producción científica del Instituto Nacional de Cancerología / National Cancer Institute scientific production scientometric analysis

Resumen Introducción: La cienciometría permite analizar la productividad e impacto de las publicaciones científicas mediante técnicas bibliométricas y computacionales. Objetivo: Proponer una metodología multidimensional para obtener el perfil cienciométrico del Instituto Nacional de Cancerología (INCan), México, y compararlo respecto a otras instituciones nacionales de salud. Método: Con el programa LabSOM y la metodología ViBlioSOM, basada en redes neuronales artificiales, se analizó la producción científica del INCan indexada en la Web of Science entre 2007 y 2017. Se obtuvo el perfil cienciométrico multidimensional del Instituto y se comparó con el de otras instituciones nacionales de salud. Resultados: En productividad, el INCan ocupa el cuarto lugar de las 10 instituciones mexicanas de salud pública indexadas en la Web of Science.; en el ranking de impacto normalizado, el sexto lugar. Aun cuando de 1323 artículos, 683 (51.62 %) no recibieron citas, 11 artículos de excelencia (0.83 %) lograron 24 % de 11 932 citas y, consecuentemente, el impacto normalizado del INCan evidenció una productividad media por arriba de la media mundial. Conclusión: El análisis multidimensional con la red neuronal propuesta permite obtener un perfil cienciométrico institucional absoluto y relativo más fidedigno e integral que el derivado de conteos de variables aisladas.

Abstract Introduction: Scientometrics analyzes scientific publications through bibliometric and computational techniques, whereby productivity and impact indicators are generated. Objective: To propose a multidimensional methodology in order to obtain the scientometric profile of the National Cancer Institute (INCan), Mexico, and rank it with regard to other national health institutions. Method: Using the LabSOM software and the ViBlioSOM methodology based on artificial neural networks, the INCan scientific production indexed in the Web of Science from 2007 to 2017 was analyzed. The multidimensional scientometric profile of the Institute was obtained and compared with that of other national health institutions. Results: In terms of productivity, INCan ranks fourth among the 10 Mexican public health institutions indexed in the Web of Science; in the normalized impact ranking, it ranks sixth. Although out of 1323 articles 683 (51.62 %) did not receive citations, 11 articles classified as excellent (0.83 %) obtained 24 % of 11,932 citations and, consequently, INCan normalized impact rate showed a mean productivity higher than the world mean. Conclusion: Multidimensional analysis with the proposed neural network enables obtaining a more reliable and comprehensive absolute and relative institutional scientiometric profile than that derived from measuring isolated variables.

Wet and dry tropical forests show opposite successional pathways in wood density but converge over time.

Tropical forests are converted at an alarming rate for agricultural use and pastureland, but also regrow naturally through secondary succession. For successful forest restoration, it is essential to understand the mechanisms of secondary succession. These mechanisms may vary across forest types, but analyses across broad spatial scales are lacking. Here, we analyse forest recovery using 1,403 plots that differ in age since agricultural abandonment from 50 sites across the Neotropics. We analyse changes in community composition using species-specific stem wood density (WD), which is a key trait for plant growth, survival and forest carbon storage. In wet forest, succession proceeds from low towards high community WD (acquisitive towards conservative trait values), in line with standard successional theory. However, in dry forest, succession proceeds from high towards low community WD (conservative towards acquisitive trait values), probably because high WD reflects drought tolerance in harsh early successional environments. Dry season intensity drives WD recovery by influencing the start and trajectory of succession, resulting in convergence of the community WD over time as vegetation cover builds up. These ecological insights can be used to improve species selection for reforestation. Reforestation species selected to establish a first protective canopy layer should, among other criteria, ideally have a similar WD to the early successional communities that dominate under the prevailing macroclimatic conditions.

Polimorfismo rs17817449 del gen FTO y su influencia en variables antropométricas de jóvenes chilenos / rs17817449 polymorphism of the fto gene and its influence on anthropometric variables of young Chileans

Determinar la distribución genotípica y la frecuencia alélica del polimorfismo rs17817449 del gen FTO en jóvenes chilenos y su influencia en variables antropométricas. Los 96 sujetos jóvenes (18-25 años), 43 hombres y 53 mujeres fueron evaluados utilizando genotipificación del polimorfismo rs17817449 del gen FTO en TT, TG y GG mediante polimerase chain reaction (PCR), además de una evaluación Kinenatropométrica para determinar las variables asociadas a composición corporal. Las variables fueron analizadas estadísticamente según su distribución paramétrica y el nivel de significancia estadística fue p<0,05. La distribución genotípica del polimorfismo rs17817449 de FTO en jóvenes chilenos fue: TT: 50 %; TG: 42,7 %; GG 7,3 % y la distribución alélica fue: T: 0,7105 y G: 0,2895. No se encontraron diferencias estadísticamente significativas en las variables antropométricas al analizar los participantes según modelo de dominancia del alelo G. Se determinó la distribución genotípica y la frecuencia alélica del polimorfismo rs17817449 del gen FTO en jóvenes chilenos, datos desconocidos hasta este momento. De acuerdo a nuestros resultados, no existen diferencias antropométricas entre personas con diferentes genotipos del polimorfismo rs17817449 de FTO, agrupadas según modelo de dominancia del alelo G.

The rs17817449 polymorphism of the FTO gene in young Chileans and their influence on anthropometric variables. 96 young subjects (18-25 years old), 43 men and 53 women were evaluated using genotyping of the rs17817449 polymorphism of the FTO gene in TT, TG and GG by means of polymerase chain reaction (PCR), in addition to a Kinenatropometric evaluation to determine the variables associated with body composition. The variables were analyzed statistically according to their parametric distribution and the level of statistical significance was p<0.05. The genotypic distribution of the FTO polymorphism rs17817449 in young Chileans was: TT: 50 %; TG: 42.7 %; GG 7.3 % and the allelic distribution was: T: 0.7105 and G: 0.2895. No statistically significant differences were found in the anthropometric variables when analyzing the participants according to model of dominance of the G allele. The genotypic distribution and the allelic frequency of the rs17817449 polymorphism of the gene were determined FTO in Chilean population, data unknown until now. According to our results, there are no anthropometric differences between people with different genotypes of the FTO polymorphism rs17817449, nor according to the dominance model of the G.

Legume abundance along successional and rainfall gradients in Neotropical forests.

The nutrient demands of regrowing tropical forests are partly satisfied by nitrogen-fixing legume trees, but our understanding of the abundance of those species is biased towards wet tropical regions. Here we show how the abundance of Leguminosae is affected by both recovery from disturbance and large-scale rainfall gradients through a synthesis of forest inventory plots from a network of 42 Neotropical forest chronosequences. During the first three decades of natural forest regeneration, legume basal area is twice as high in dry compared with wet secondary forests. The tremendous ecological success of legumes in recently disturbed, water-limited forests is likely to be related to both their reduced leaflet size and ability to fix N2, which together enhance legume drought tolerance and water-use efficiency. Earth system models should incorporate these large-scale successional and climatic patterns of legume dominance to provide more accurate estimates of the maximum potential for natural nitrogen fixation across tropical forests.

Photoprotection related to xanthophyll cycle pigments in epiphytic orchids acclimated at different light microenvironments in two tropical dry forests of the Yucatan Peninsula, Mexico.

MAIN CONCLUSION: Epiphytic orchids from dry forests of Yucatán show considerable photoprotective plasticity during the dry season, which depends on leaf morphology and host tree deciduousness. Nocturnal retention of antheraxanthin and zeaxanthin was detected for the first time in epiphytic orchids. In tropical dry forests, epiphytes experience dramatic changes in light intensity: photosynthetic photon flux density may be up to an order of magnitude higher in the dry season compared to the wet season. To address the seasonal changes of xanthophyll cycle (XC) pigments and photosynthesis that occur throughout the year, leaves of five epiphytic orchid species were studied during the early dry, dry and wet seasons in a deciduous and a semi-deciduous tropical forests at two vertical strata on the host trees (3.5 and 1.5 m height). Differences in XC pigment concentrations and photosynthesis (maximum quantum efficiency of photosystem II; F v/F m) were larger among seasons than between vertical strata in both forests. Antheraxanthin and zeaxanthin retention reflected the stressful conditions of the epiphytic microhabitat, and it is described here in epiphytes for the first time. During the dry season, both XC pigment concentrations and photosystem II heat dissipation of absorbed energy increased in orchids in the deciduous forest, while F v/F m and nocturnal acidification (ΔH(+)) decreased, clearly as a response to excessive light and drought. Concentrations of XC pigments were higher than those in orchids with similar leaf shape in semi-deciduous forest. There, only Encyclia nematocaulon and Lophiaris oerstedii showed somewhat reduced F v/F m. No changes in ΔH(+) and F v/F m were detected in Cohniella ascendens throughout the year. This species, which commonly grows in forests with less open canopies, showed leaf tilting that diminished light interception. Light conditions in the uppermost parts of the canopy probably limit the distribution of epiphytic orchids and the retention of zeaxanthin can help to cope with light and drought stress in these forests during the dry season.

A roadmap for research on crassulacean acid metabolism (CAM) to enhance sustainable food and bioenergy production in a hotter, drier world.

Crassulacean acid metabolism (CAM) is a specialized mode of photosynthesis that features nocturnal CO2 uptake, facilitates increased water-use efficiency (WUE), and enables CAM plants to inhabit water-limited environments such as semi-arid deserts or seasonally dry forests. Human population growth and global climate change now present challenges for agricultural production systems to increase food, feed, forage, fiber, and fuel production. One approach to meet these challenges is to increase reliance on CAM crops, such as Agave and Opuntia, for biomass production on semi-arid, abandoned, marginal, or degraded agricultural lands. Major research efforts are now underway to assess the productivity of CAM crop species and to harness the WUE of CAM by engineering this pathway into existing food, feed, and bioenergy crops. An improved understanding of CAM has potential for high returns on research investment. To exploit the potential of CAM crops and CAM bioengineering, it will be necessary to elucidate the evolution, genomic features, and regulatory mechanisms of CAM. Field trials and predictive models will be required to assess the productivity of CAM crops, while new synthetic biology approaches need to be developed for CAM engineering. Infrastructure will be needed for CAM model systems, field trials, mutant collections, and data management.

Apendicectomía laparoscópica a 2 puertos (15-5 mm) utilizando un dispositivo puerto En guante simplificado / Laparoscopic appendectomy with 2 ports (15-5 mm) using a simplified globe as a device port

Objetivo: Presentar nuestra experiencia en apendicectomías laparoscópicas a 2 puertos (15-5mm), utilizando un dispositivo elaborado con material de quirófano: puerto en guante simplificado, en el servicio de Cirugía General del Hospital Dr. Leopoldo Manrique Terrero. Métodos: Estudio prospectivo, observacional. Fueron intervenidos 15 pacientes con la técnica de apendicectomía laparoscópica a 2 puertos (15-5 mm), utilizando un dispositivo puerto en guante simplificado entre septiembre del 2012 y abril del 2013. Se analizó edad, sexo, tiempo quirúrgico, estancia hospitalaria, complicaciones, conversión a otra técnica, y los efectos estéticos. Resultados: Predominó el sexo masculino (73%), la edad promedio fue 29 años, el tiempo quirúrgico promedio fue de 46 min, el tiempo de hospitalización fue de 24 horas, no hubo conversión a otra técnica, no hubo complicaciones, los resultados estéticos fueron valorados en escala subjetiva como muy bueno. Conclusión: La técnica de apendicectomía laparoscópica a 2 puertos constituye una alternativa quirúrgica segura y confiable, perfectamente reproducible en nuestro medio, además de tener similar costo que la laparoscopia tradicional, aportando beneficios adicionales estéticos y sin utilizar instrumental especial(AU)

Objective: To present our experience in two ports laparoscopic appendectomies (15-5 mm), using a device elaborated totally with operating room supplies: simplified glove port. Study performed at General Surgery Service of Hospital Dr. Leopoldo Manrique_Terrero, Caracas. Methods: This is a prospective, observational study. Fifteen patients were operated by two ports laparoscopic appendectomy technique (15-5 mm), using a simplified glove port, between September, 2012 and April, 2013. It was analyzed age, gender, operative time, hospital stay, complications, conversion to other technics and aesthetic purposes. Results: Males were predominated in 73%, the average age was 29 years, surgical time average was 46 min. Hospital stay was 24 hours, without intraoperative complications. The aesthetic results were assessed in very good as subjective scale. Conclusion: The technique two-port laparoscopic appendectomy is a safe and reliable alternative surgical, perfectly reproducible in addition to our average cost similar to traditional laparoscopic, providing additional aesthetic benefits without using instrumental special(AU)

Environmental regulation of carbon isotope composition and crassulacean acid metabolism in three plant communities along a water availability gradient.

Expression of crassulacean acid metabolism (CAM) is characterized by extreme variability within and between taxa and its sensitivity to environmental variation. In this study, we determined seasonal fluctuations in CAM photosynthesis with measurements of nocturnal tissue acidification and carbon isotopic composition (δ(13)C) of bulk tissue and extracted sugars in three plant communities along a precipitation gradient (500, 700, and 1,000 mm year(-1)) on the Yucatan Peninsula. We also related the degree of CAM to light habitat and relative abundance of species in the three sites. For all species, the greatest tissue acid accumulation occurred during the rainy season. In the 500 mm site, tissue acidification was greater for the species growing at 30% of daily total photon flux density (PFD) than species growing at 80% PFD. Whereas in the two wetter sites, the species growing at 80% total PFD had greater tissue acidification. All species had values of bulk tissue δ(13)C less negative than -20‰, indicating strong CAM activity. The bulk tissue δ(13)C values in plants from the 500 mm site were 2‰ less negative than in plants from the wetter sites, and the only species growing in the three communities, Acanthocereus tetragonus (Cactaceae), showed a significant negative relationship between both bulk tissue and sugar δ(13)C values and annual rainfall, consistent with greater CO(2) assimilation through the CAM pathway with decreasing water availability. Overall, variation in the use of CAM photosynthesis was related to water and light availability and CAM appeared to be more ecologically important in the tropical dry forests than in the coastal dune.