Transcriptional memory and response to adverse temperatures in plants / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Temperature is one of the major environmental signals controlling plant development, geographical distribution, and seasonal behavior. Plants perceive adverse temperatures, such as high, low, and freezing temperatures, as stressful signals that can cause physiological defects and even death. As sessile organisms, plants have evolved sophisticated mechanisms to adapt to recurring stressful environments through changing gene expression or transcriptional reprogramming. Transcriptional memory refers to the ability of primed plants to remember previously experienced stress and acquire enhanced tolerance to similar or different stresses. Epigenetic modifications mediate transcriptional memory and play a key role in adapting to adverse temperatures. Understanding the mechanisms of the formation, maintenance, and resetting of stress-induced transcriptional memory will not only enable us to understand why there is a trade-off between plant defense and growth, but also provide a theoretical basis for generating stress-tolerant crops optimized for future climate change. In this review, we summarize recent advances in dissecting the mechanisms of plant transcriptional memory in response to adverse temperatures, based mainly on studies of the model plant

Influence of acute high altitude exposure and short-term acclimation on platelet-associated parameters in healthy young man / 解放军医学杂志

Objective To explore the effect of high altitude exposure and short-term acclimation on the platelet-associated parameters by studying the changes of platelet-associated parameters in healthy young man.Methods Four hundred and sixtytwo young men were recruited from Chengdu (the elevation of 500m) during Jun.2012 to Aug.2013 according to the inclusion and exclusion criteria,of which 193 had been living in Chengdu (plain group),and 269 flew from Chengdu to Lhasa (3700m) in 2 hours,and then 147 of them were exposed in the high altitude for 1 day (acute high altitude exposure group),and another 122 for 7 days (short-term acclimation group).The demographic data were collected and the blood routine and platelet-associated parameters were measured of all the participants,and then the information collected were compared between the 3 groups.Results Compared to the plain group,the platelet count (PLT),platelet distribution width (PDW) and plateletcrit (PCT) reduced and the mean platelet volume (MPV) increased significantly (P＜0.05) in the acute high altitude exposure group;while all the indexes in short-term acclimation group returned to approach the levels in the plain group,but statistical differences still existed in PLT,PDW and PCT (P＜0.05).The platelet activating factor (PAF) and epinephrine (Epi) decreased markedly in acute high altitude exposure group than in plain group (P＜0.05);while in short-term acclimation group,the PAF returned to approach the level in plain group,and the Epi was further down (P＜0.05).In addition,no marked difference of 5-HT level was observed in the 3 groups (P＞0.05).Pearson correlation analysis indicated that high altitude-induced reduction of oxygen saturation (SpO2) was positively related to the changes of PLT.Conclusions Acute high altitude exposure may reduce PLT,PDW and PCT levels,but elevate MPV and enhance the platelet activity.The reduction of SpO2 might be associated with the changes of PLT,PDW and PCT.Platelet-associated parameters may be recovered to normal with a compensatory effect after short-term acclimation.

Optimized acid hydrolysis of the polysaccharides from the seaweed Solieria filiformis (Kützing) P.W. Gabrielson for bioethanol production / Hidrólise ácida otimizada dos polissacarídeos da macroalga Solieria filiformis (Kützing) P.W. Gabrielson para produção de bioetanol

The seaweeds are bio-resource rich in sulfated and neutral polysaccharides. The tropical seaweed species used in this study (Solieria filiformis), after dried, shows 65.8% (w/w) carbohydrate, 9.6% (w/w) protein, 1.7% (w/w) lipid, 7.0% (w/w) moisture and 15.9% (w/w) ash. The dried seaweed was easily hydrolyzed under mild conditions (0.5 M sulfuric acid, 20 min.), generating fermentable monosaccharides with a maximum hydrolysis efficiency of 63.21%. Galactose and glucose present in the hydrolyzed were simultaneously fermented by Saccharomyces cerevisiae when the yeast was acclimated to galactose and cultivated in broth containing only galactose. The kinetic parameters of the fermentation of the seaweed hydrolyzed were Y(P/S) = 0.48 ± 0.02 g.g−1, PP = 0.27 ± 0.04 g.L−1.h−1, η = 94.1%, representing a 41% increase in bioethanol productivity. Therefore, S. filiformis was a promising renewable resource of polysaccharides easily hydrolyzed, generating a broth rich in fermentable monosaccharides for ethanol production.

As algas marinhas são recursos naturais ricos em polissacarídeos sulfatados e neutros. A espécie de macroalga tropical utilizada neste estudo (Solieria filiformis) apresentou teores de carboidratos de 65,8% (m/m), proteínas de 9,6% (m/m), lipídios de 1,7% (m/m), umidade de 7,0% (m/m) e 15,9 % (m/m) de cinzas. A macroalga seca foi facilmente hidrolisada em condições brandas, na presença de ácido sulfúrico 0,5 M, por 20 min, produzindo monossacarídeos fermentáveis com uma eficiência de hidrólise máxima de 63,21%. A galactose e a glicose presentes no hidrolisado foram fermentadas simultaneamente por Saccharomyces cerevisiae, após aclimatação da levedura cultivada em meio contendo apenas galactose como fonte de carbono. Os parâmetros cinéticos da fermentação do hidrolisado algáceo pela levedura aclimatada a galactose foram Y(P/S) = 0,48 ± 0,02 g.g-1, PP = 0,27 ± 0,04 g.L- 1.h-1, η = 94,1%. Portanto, a macroalga S. filiformis se mostrou um recurso renovável promissor como fonte de polissacarídeos facilmente hidrolisados, gerando um meio nutritivo rico em glucose e galactose para a produção de etanol.

"Plantas novas que os doutos não conhecem": a exploração científica da natureza no Oriente português, 1768-1808 / "New plants that scholars do not know": scientific exploration of nature in Portuguese East Asia, 1768-1808

Resumo Com a perda da maioria de suas conquistas para os neerlandeses, o Oriente português ficou reduzido a feitorias residuais, e o Brasil passou a ocupar o centro das atenções nas políticas coloniais. Assim, no século XVIII, a Coroa portuguesa não demonstrou grandes interesses em desenvolver o conhecimento autônomo da natureza do Oriente. Tais interesses se apresentavam vinculados a propósitos de reconfigurar a economia das colônias brasileiras. Ganhava corpo o intuito de aclimatar no Brasil espécies orientais de interesse econômico, como a pimenta-da-índia, a noz-moscada, a canela, o cravo, a teca e o sândalo, propósito que não foi imediatamente bem-sucedido. O artigo acompanha essa tentativa de estender ao Oriente a rede científica portuguesa e o processo de transplantação de espécies.

Abstract As Portugal lost most of its conquests to the Dutch, Portuguese East Asia was reduced to the remaining trading posts (feitorias) and Brazil became the center of attention for colonial policies. Consequently, during the eighteenth century the Portuguese crown did not express greater interest in developing native Eastern knowledge of nature. These interests were tied to goals involving reconfiguration of the economy of the Brazilian colonies. The idea to cultivate economically important Eastern species such as pepper, nutmeg, cinnamon, cloves, teak, and sandalwood in Brazil took shape, but was not immediately successful. This article examines this attempt to extend Portugal's scientific network to the East, as well as the process of transplanting these species.

Growth responses and accumulation of soluble sugars in Inga marginata Wild. (Fabaceae) subjected to flooding under contrasting light conditions / Respostas de crescimento e acúmulo de açúcares solúveis em Inga marginata Willd. (Fabaceae) submetida ao alagamento e sob condições contrastantes de luminosidade

Abstract Flood events in riparian forests of southern Brazil, can be characterized as unpredictable and of low magnitude with an average duration of less than 15 days. Inga marginata is an evergreen tree which grows in Southeast South America on a wide range of environments, including riparian forests. In this paper, the interactive effects of the light environment and soil flooding on morphological parameters of I. marginata were examined. Seedlings were acclimated in two contrasting light conditions: sun or shade for 30 days. Sun and shade plants were subjected to soil flooding for two periods; five or 15 days. After 5 days, the interaction between flooding and light did not affect growth, chlorophyll content and dry mass or the root-shoot ratio. After 15 days, flooded plants from the sunny treatment had a lower shoot dry mass compared to control sun plants and flooded plants from the shaded treatment. Moreover, the higher dry mass observed for shade plants compared to sun plants, following flooding, can also be directly associated with a higher content of soluble sugars. Shade plants of I. marginata showed a greater acclimation to soil waterlogging. This acclimation appears to be associated with a larger accumulation of soluble sugars compared to non-flooded plants. The responses observed on the shade plants appear to be decisive to indicate the use of I. marginata in degraded areas.

Resumo As inundações em florestas ripárias do Sul do Brasil, podem ser caracterizadas como imprevisíveis e de baixa magnitude com uma duração média de menos de 15 dias. Inga marginata é uma árvore que cresce no sudeste da América do Sul em uma grande variedade de ambientes, incluindo matas ciliares. Neste trabalho, os efeitos combinados da luminosidade e do e alagamento do solo nos parâmetros morfológicos de I. marginata foram examinados. As plântulas foram aclimatadas em duas condições contrastantes de luminosidade: sol e sombra por 30 dias. Plantas de sol e sombra foram submetidas ao alagamento do solo por dois períodos; cinco ou 15 dias. Após 5 dias, a interação entre a inundação e luminosidade não afetou o crescimento, teor de clorofila e massa seca e a razão raiz-parte aérea. Após 15 dias, plantas de sol sob inundação apresentaram menor massa seca na parte aérea em relação as plantas controle de sol e as plantas alagadas de sombra. Além disso, a maior massa seca observada nas plantas de sombra em comparação com plantas de sol, sob inundação, pode ser diretamente associado com um maior teor de açúcares solúveis. Plantas de sombra de I. marginata mostraram uma maior aclimatação ao encharcamento do solo. Esta aclimatação parece estar associada com um maior acúmulo de açúcares solúveis em comparação com as plantas não-inundadas. As respostas observadas nas plantas de sombra parecem ser determinantes para a indicação do uso de I. marginata em áreas degradadas.

Factors affecting heat-related diseases in outdoor workers exposed to extreme heat

BACKGROUND: The objectives of the present study are to: (i) evaluate the effect of environmental and metabolic heat on heat-related illnesses in outdoor workers; and (ii) evaluate the effect of personal factors, including heat acclimation, on the risk of heat-related illnesses in outdoor workers. METHODS: We identified 47 cases of illnesses from exposure to environmental heat in outdoor workers in Korea from 2010 to 2014, based on review of workers' compensation data. We also obtained the information on location, time, and work environment of each heat-related illness. RESULTS: Our major results are that 29 cases (61.7%) occurred during a heat wave. Forty five cases (95.7%) occurred when the maximum estimated WBGT (WBGTmax) was equal to or greater than the case specific threshold value which was determined by acclimatization and metabolic rate. Twenty two cases (46.8%) were not acclimated to the heat. Thirty-seven cases (78.7%) occurred after tropical night (temperature above 25 °C), during which many people may find it hard to sleep. CONCLUSION: Personal risk factors such as heat acclimation as well as environmental factors and high metabolic rate during work are the major determinants of heat-related illnesses.

Effect of heat acclimation on mitochondrion of cerebral cortex and myocardium in rats stimulated by exercise in hygrothermal environment / 第二军医大学学报

Objective To explore whether heat acclimation can protect the structure and function of mitochondrion of cerebral cortex and myocardium in rats with moderate and high intensity exercise in hygrothermal environment, and to explore its protective mechanism. Methods Forty SD rats underwent swimming experiment bearing weight and 8 rats were eliminated due to too short-swim or long-swim time. The rest 32 rats were randomly divided into four groups (n=8): room-temperature activity (RA) group? room-temperature exercise (RE) group, high-temperature activity (HA) group and high-temperature exercise (HE) group. Rats in RA and HA groups were placed at room temperature ([24±1] °C) and high temperature ([32±1] C) to have a free activity for 2 h/d. Rats in RE and HE groups were placed at room temperature ([24±1] °C) and high temperature ([32 ± 1] °C) to have a free activity for 1 h/d and then were allowed to run at a constant speed on the animal treadmill for 1 h/d (slope: 0% speed: 14 m/min). After 14 days the heat acclimation rat models were created. Rats in all groups underwent moderate and high intensity exercise in hygrothermal environment for 30 min on the 3rd day. The body weight loss rate and rectal temperatures of rats were measured before and after high and medium intensity exercise in hygrothermal environment. The contents of plasma norepinephrine (NE), arginine vasopressin (AVP) and Cortisol (Cort) in rats were detected by radioimmunoassay. The ultras true ture of the mitochondria of cerebral cortex and myocardium was observed by transmission electron microscopy. The contents of ATP synthase and reactive oxygen species (ROS) were detected by ELISA method and the total antioxidative capacity was measured by ABTS method. Results The rectal temperatures before and after stimulation and the ascending range of rectal temperatures of rats in HE group were significantly lower than those in the RA, RE and HA groups (P<0. 05 9 P<0. 01). After stimulation with moderate and high intensity exercise in hygrothermal environment, the body weight loss rate of rats in HE group was significantly higher than that in RA group (P<0. 01) 9 the contents of plasma Cort and ROS of rats in HE group were significantly lower than those in the RA, RE and HA groups (P<0. 05, P<0. 01), the content of ATP synthase in mitochondrion and total antioxidative capacity in tissue from cerebral cortex and myocardium of rats in HE group were significantly higher than those in the RA, RE and HA groups (P < 0. 01), and the mitochondrion and synaptic structures in the cerebral cortex and the structures of myocardium, Z line and transverse tubule in the myocardium in HE group were superior to those in the RA, RE and HA groups. Conclusion Heat acclimation can enchance the oxidative and respiratory function of mitochondria and reduce the level of cell oxidative stress and the content of plasma Cort, so as to protect the mitochondrial structure of cerebral cortical neurons and cardiomyocytes in rats with moderate and high intensity exercise in hygrothermal environment.

Seasonal acclimation in sudomotor function evaluated by QSART in healthy humans

The quantitative sudomotor axon reflex testing (QSART) is a classic test of routine postganglionic sudomotor function. We investigated sudomotor function by QSART after summer (July 2012) and winter (January 2013) seasonal acclimation (SA) in the Republic of Korea. QSART with acetylcholine (ACh) iontophoresis were performed to determine directly activated (DIR) and axon reflex-mediated (AXR1, 2) sweating rate. Onset time of axon reflex, activated sweat gland density (ASGD), activated sweat gland output (ASGO), tympanic and skin temperatures (T(ty), T(sk)), basal metabolic rate (BMR), and evaporative loss volume changes were measured. Tympanic and mean body temperature (T(b); calculated from T(ty), T(sk)) were significantly lower after summer-SA than that of winter-SA. Sweat onset time was delayed during winter-SA compared to that after summer-SA. BMR, AXR(1), AXR(2), and DIR sweat rates, ASGD and ASGO, and evaporative loss volume were significantly diminished after winter-SA relative to after summer-SA. In conclusion, changes in sweating activity measured by QSART confirmed the involvement of the peripheral nervous system in variation of sudomotor activity in seasonal acclimation.

Effect of heat acclimation on metabolites in rat blood / 第二军医大学学报

Objective To observe the changes of plasma metabolites in rats after heat acclimation and following exercise stimulation, so as to screen the specific marker of heat acclimation. Methods A total of 16 SD rats were randomly divided into control and heat acclimation groups (n=8); rats in the heat acclimation group received 2 hour training a day and those in the control group received no training. After 14 days of heat acclimation, rat orbital blood was collected from control and heat acclimation groups. After a rest for 4 days, rat arterial blood samples were collected under anesthesia after exercising in a thermal environment for 30 min in both groups. The changes of metabolites in the plasmas from control and heat acclimation groups were examined by the nuclear magnetic resonance (NMR)using Bruker 600 MHz, and the changes of plasma metabolites were analyzed after heat acclimation and stimulation with exercise in thermal environment in rats. Results Compared with control group, the heat acclimation group had significantly increased plasma unsaturated lipid, glutamate, lipid and dimethylamine(P<0. 05), and significantly decreased glucose, myo-inositol, taurine, threonine and trimethylamine N-oxide (TMA0)(P<0. 05). After heat stimulation with exercise in thermal environment the plasma TMAO, glutamate and lipid were significantly decreased in the heat acclimation group (P<0. 05). Conclusion After heat acclimation and exercise stimulation in thermal environment, plasma metabolites undergo great changes m rats. TMAO may serve as a marker of heat acclimation, which provide evidence for establishing evaluation system for heat acclimation.

Critical thermal limits of Poecilia caucana (Steindachner, 1880) (Cyprinodontiformes: Poeciliidae)

Aunque la temperatura tiene grandes repercusiones en la biología de los peces, se desconocen los rangos de tolerancia térmica de la mayoría de los peces dulceacuícolas. Esta falta de información impide pronosticar respuestas al cambio climático y limita los análisis comparativos que podrían enriquecer estudios evolutivos y biogeográficos. Utilizamos la metodología del crítico térmico para cuantificar la capacidad de aclimatación y la tolerancia térmica en la especie neotropical dulceacuícola Poecilia caucana. Para peces aclimatados a 20C, 25ºC y 28ºC, los críticos térmicos mínimos (CTmin) fueron 12,52 ± 0,62ºC, 13,41 ± 0,56ºC y 14,24 ± 0,43ºC, respectivamente, y los críticos térmicos máximos (CTmax) fueron 38,43 ± 0,64ºC, 40,28 ± 0,92ºC y 41,57 ± 0,27ºC, respectivamente. Tanto el CTmin como el CTmax cambiaron significativamente con las temperaturas de aclimatación, indicando que P. caucana es efectivamente aclimatable. Comparada con otras especies de peces dulceacuícolas, la capacidad de aclimatación de P. cuacana fue baja para CTmin y promedio para CTmax. Estos resultados, en conjunto con los datos de otras especies, pueden ser utilizados para responder preguntas ecológicas y evolutivas más generales.

Although temperature has far-reaching effects on fish biology, the thermal tolerance ranges of most freshwater fish species are unknown. This lack of information precludes forecasting responses to climatic change and does not allow for comparative analyses that may inform evolutionary and biogeographic studies. We used the critical thermal methodology to quantify acclimation capacity and thermal tolerance in the Neotropical freshwater species Poecilia caucana . For fish acclimated to 20C, 25ºC, and 28ºC, critical thermal minima (CTmin) were 12.52 ± 0.62ºC, 13.41 ± 0.56ºC and 14.24 ± 0.43ºC respectively, and critical thermal maxima (CTmax) were 38.43 ± 0.64ºC, 40.28 ± 0.92ºC and 41.57 ± 0.27ºC, respectively. Both CTmin and CTmax changed with acclimation temperatures, indicating that P. caucana was effectively acclimatable. Relative to values reported for other freshwater fish species, the acclimation capacity of P. caucana for CTmin was low, but it was average for CTmax. The data, together with similar work in other species, can be used in analyses focusing on broad ecological and evolutionary questions.

Effect of pH in the survival of Lactobacillus salivarius strain UCO_979C wild type and the pH acid acclimated variant

Background Bacterial acclimation involves cellular changes permitting the survival of a microorganism to prolonged acid pH exposure. The general aim of this work is to support this idea by determining the effect of pH in the survival of the human gastric derived probiotic strain Lactobacillus salivarius UCO_979C-1 (wild type) and L. salivarius UCO_979C-2 (acclimation to pH 2.6), which possesses anti-Helicobacter pylori properties. Results To assess this aim, the exopolysaccharide production through the phenol-sulfuric acid method was evaluated. Moreover, morphological and structural changes by transmission and scanning electron microscopy were observed. The bacterial survival was measured by viable count. The results showed that the acclimated variant strain synthesized higher levels of exopolysaccharide (690 ± 0.03 mg/L) more than the wild type (450 ± 0.12 mg/L). In addition, the acclimated variant preserved the viable count at pH 2.6 for 48 h, whereas the wild type strain decreases after 6 h and was non-viable at 24 h. Conclusion The results suggest that the acid stress acclimation of the strain L. salivarius UCO_979C-1 modified some cellular properties making this strain potentially useful as a gastric probiotic.

Adaptive thermogenesis of the brown adipose tissue in tree shrews (Tupaia belangeri) during cold acclimation / 中国实验动物学报

Objective To investigate the effect of ambient temperature on body mass, thermogenic activity and un-coupling protein-1 ( UCP1) content of brown adipose tissue ( BAT) in tree shrews ( Tupaia belangeri) , and to provide the-oretical basis for establishing tree shrews model of obesity.Methods Forty healthy adult tree shrews with similar body mass were uesd in our experiment.The tree shrews were divided into five groups (n=8):control group (0 d), the ani-mals were maintained under 25 ±1℃ and 12L:12D ( light : dark, lights on 08:00) photoperiod; and the animals were maintained under 5 ±1℃and 12L:12D photoperiod for 7 d, 14 d, 21 d and 28 d groups, respectively.At the end of ex-periment, the changes of body mass, nonshivering thermogenesis (NST), BAT mass and uncoupling protein 1 (UCP1) con-tent were determined.Results Compared with the control group (0 d), the body mass, NST, BAT mass and UCP1 con-tent of the cold acclimation groups were improved significantly, the BAT color also obviously deepened, and after cold accli-mation for 28 d, the body mass, NST, BAT mass and UCP1 content were increased by 26.32%, 20.65, 53.85%and 43%, respectively.Apparently, the UCP1 content was significantly positively correlated with BAT mass and NST.Conclusions BAT proliferation may be induced and UCP1 expression upregulated by cold acclimation in Tupaia belangeri, therefore, en-hancing the thermogenic activity of brown adipose tissue to increase energy expenditure.We would speculate that BAT might be used as a target organ for treatment of obesity by energetic approach in the future.

Evidencia del comportamiento circadiano de la epo con dependencia del sexo e independencia de parámetros fisiológicos en jóvenes entrenados en la altura moderada / Sex dependent and physiologically independent circadian variation in epo in young amateur athletes / Evidencia do comportamento circadiano da epo com dependência do sexo e independência de parâmetros fisiológicos em jovens treinados na altura moderada

La importancia de la Epo como hormona central en los procesos de ambientación a la altura es clara dado su efecto estimulante sobre la producción eritrocitaria. Su naturaleza hormonal ha llevado a que algunas investigaciones evalúen su circadianidad con reportes no contundentes e inclusive contradictorios al respecto. Objetivo: Analizar la circadianidad de la Epo en sujetos que realizan entrenamiento aeróbico en la altura intermedia (2600 msnm) comparando diferencias entre hombres y mujeres. Materiales y métodos: Se reclutaron residentes a la altura intermedia de por lo menos 18 meses, de ambos sexos y que tuvieran entrenamiento aeróbico al menos durante 8 meses previos a la realización del estudio para medir su Epo cada 4 horas durante 24 horas y correlacionarla con algunas variables fisiológicas y ambientales. Resultados: Existe comportamiento circadiano en la Epo tanto para hombres como para mujeres, con un mesor para hombres de 20:10 h y 16:33 h para mujeres. En cuanto a la acrofase, esta se presenta hacia las 17:52 h para hombres y a las 15:50 h para las mujeres. El análisis de diferencia de medias muestra una diferencia estadísticamente significativa entre los dos grupos Conclusión: Existe circadianidad diferencial entre hombres y mujeres en cuanto a sus niveles de Epo, la cual es independiente de variables fisiológicas y ambientales. Tema: Ritmo circadiano. Subtema: Eritropoyetina.

Erythropoietin Epo is the key hormone in the process of erythropoiesis and, therefore, essential for acclimation to altitude. Although circadian variation in Epo levels has been reported before, the results are often contradictory. Here, we tested the hypothesis that Epo levels follow a circadian variation and that such variation depends on gender and standard physiological variables. We evaluated circadian variation in Epo levels in amateur young athletes living at intermediate elevation (Bogota, Colombia: 2600 m) and analyzed the potential association with physiological variables. Materials and Methods: Six men and six women were included in the study assuring at least eight months of aerobic regime before participation. We took blood samples every 4 h over 24 h to quantify Epo levels and measured physiological variables (hear rate, blood pressure, oxygen saturation). Results: Our results show a circadian variation in Epo levels (cosinor analysis p<0.05) and a significant difference in mesor (men = 20:10 h, women = 16:33 h, p = 0.0001) and acrophase between males and females (men = 17:52 h, women = 15:50 h). In contrast, we did not detect any significant association with the physiological variables measured. Conclusion: We conclude that there is a circadian variation in Epo levels and that such rhythmicity is dependent on gender and independent of physiological variables. Ongoing research aims to detect the controller of the oscillation detected in this project. Themes: Circadian Rhythm. Topics: Erythropoietin.

A importância da Epo como hormona central nos processos de adaptação na altura é evidente dado o efeito estimulante sobre a produção eritrocitária. Sua natureza hormonal tem levado à pesquisa da circadianidade desta, com resultados não contundentes e inclusive contraditórios. Objetivo: Analisar de forma comparativa a circadianidade da Epo em homens e mulheres que fazem treinamento aeróbico na altura intermedia (2600 msnm). Materiais e Métodos: Foram incluídos residentes na altura intermedia, com uma idade mínima de 18 meses, ambos sexos, e treinamento aeróbico durante pelo menos 8 meses prévios da realização da investigação. Na população incluída, a Epo foi medida com intervalo de 4 horas (durante 24 horas) com o fim de correlaciona-la com algumas variáveis fisiológicas e ambientais. Resultados: Existe comportamento circadiano na Epo tanto em homens (mesor: 20:10 h) quanto em mulheres (mesor: 16:33 h). A acrofase se apresentou às 17:52 h nos homens e às 15;50 h nas mulheres. A análise comparativa de medidas descreve uma diferença estatisticamente significativa entre os dois grupos avaliados. Conclusão: Existe circadianidade diferencial entre homens e mulheres nos níveis da Epo, sendo independente das variáveis fisiológicas e ambientais. Tópico: Ritmo circadiano Subtópico: Eritropoietina.

Growth of seedlings Jatropha curcas L. irrigated with saline water / Crescimento de mudas de pinhão manso, Jatropha curcas L. irrigadas com água salina

The species Jatropha curcas is a rustic plant, adapted to several edaphoclimatic conditions, being constantly explored in marginal conditions, however, ensuring production will be greater with the use of irrigation and fertile soil, when it'll be necessary to research the possibility of its cultivation with saline water. Therefore the present study aims at assessing the effect of the electrical conductivity of irrigation water on the morphophysiological answers of seedlings from J. curcas L. The work was conducted in shade with 50% of solar radiation interception at the State University of Goiás. The experiment was set up following a completely randomized design with four treatments and five repetitions. Sowing occurred in four-liter containers containing soil, sand and manure in the ratio of 3: 1: 0.5 respectively. During the seedling stage (60 days), the plants were subjected to four treatments: plants irrigated daily with 150 ml of deionized water containing NaCl, and electrical conductivity of 0.0 dS m-1 (T1), 3 dS m-1 (T2), 6 dS m-1 (T3) and 9 dS m-1 (T4). The high concentration of salt reduced the free energy of the water, making it limiting. The water limitation caused a reduction in the leaf area and in the number of leaves, contributing to the reduction of perspiring area and the maintenance of tissue hydration. The high electrical conductivity of irrigation water reduced the seedling growth J. curcas, however, plants of J. curcas can be irrigated with saline water of conductivity less than or equal to 3 dS m-1 without significant damage to vegetative growth.

Acclimation of seedlings of Gnetum leyboldii Tul. Gnetaceae to light changes in a tropical rain forest / Aclimatación de plántulas de Gnetum leyboldii Tul. Gnetaceae a los cambios de luz en un bosque lluvioso tropical

The neotropical liana Gnetum leyboldii Gnetaceae is a gymnosperm that resembles angiosperms in wood anatomy, overall morphology, and seed dispersal mechanism. Like other woody lianas, seedlings germinate in the shaded forest understory and start climbing towards the canopy, being eposed to sites with etreme differences in light conditions. However, the etent of physiological and structural adjustment to contrasting light conditions in the early regeneration stages of Gnetum is unknown. To answer this question, we analyzed seedling growth and photosynthetic responses using a common garden eperiment with two light regimes: full sun and low light 20 of full sun at La Selva Biological Station, Costa Rica. We also characterized the germination pattern of this species. We monitored one and half-month old seedlings for four months. Leaf structure finely adapted to light treatments, but gas echange properties were buffered by large seed reserves, which dominated biomass distribution about 50 of the total biomass, followed by stem 27, leaf 16 and root biomass 6 across light conditions. The presence of large seeds and the low photosynthetic rates of seedlings in both environments show that G. leyboldii is specialized to eploit deep shade. More research is needed to determine if the patterns found in G. leyboldii are typical of similar lianas that initially eploit deep-shaded understories in their ascension to the canopy.

La liana neotropical Gnetum leyboldii Gnetaceae es una gimnosperma que se asemeja a las angiospermas en la anatomía de la madera, morfología general de la planta y mecanismo de dispersión de semillas. Al igual que otras lianas leñosas, las plántulas se regeneran en el sotobosque bajo dosel cerrado y eventualmente ascienden hacia el dosel, eplotando sitios con diferencias etremas en condiciones lumínicas. Se desconoce el grado de ajuste fisiológico a condiciones lumínicas contrastantes en las primeras fases de regeneración de Gnetum. Para contestar esta pregunta, analizamos las respuestas de crecimiento de las plántulas a ambientes contrastantes de luz de sol y sombra en un jardín común con condiciones de alta cielo abierto y baja luminosidad 20 del ambiente de sol en la Estación Biológica La Selva, Costa Rica. También caracterizamos su patrón de germinación. Monitoreamos plántulas de 1.5 meses de edad por 4 meses. La estructura foliar mostró una fina adaptación a los tratamientos de luz, pero las propiedades de intercambio gaseoso no cambiaron sino que fueron amortiguadas por las reservas de las semillas grandes, las cuales dominaron la distribución de biomasa aproimadamente 50 de la biomasa total seguidas por el tallo 27, la hoja 16 y raíces 6. El tener semillas grandes y plántulas con bajas tasas fotosintéticas muestra que G. leyboldii en su etapa de plántula está adaptado para eplotar la sombra profunda. Se requiere más investigación para determinar si los patrones encontrados en G. leyboldii son típicos de otras lianas que inicialmente eplotan la sombra profunda en su ascensión al dosel.

Switching between Heat Shock Proteins and Cold Inducible Proteins under Temperature Fluctuation in Solanum tuberosum L. Cultivars in In Vivo Condition.

Cross-talking between heat shock proteins (HSPs) and cold inducible proteins (CIPs) subsequent to combinational mild heat (35°C) and cold (8°C) stress was investigated in vivo for four cultivars of Solanum tuberosum L. viz. Kufri Pukhraj (PO), Kufri Jyoti (GS), Kufri Ashoka (KF) and Kufri Chandramukhi (CM) in the order of their decreasing thermotolerance, to understand how this economic crop adapts to extreme temperature fluctuation. We showed a time-course differential genotypic expression pattern for HSPs at 35°C for 10h and CIPs at 8°C for 12h time-lapse. Remarkably, we noted the disappearance of a housekeeping protein (HKP) of about 19.8KD at 2h, 35°C in GS absent in CM, KF and PO; but strongly expressed as CIPs at 8°C for all the cultivars. Furthermore, heat-stress led to an outstanding transient induction of HSP95.9, HSP83.6, HSP78.7, HSP70.7, HSP66.0, HSP54.1, HSP48.6, HSP43, sHSP38.3, sHSP35.3, sHSP29, sHSP22.5, sHSP17.8 and sHSP9.5 in GS at 6h, while HKP58.7, HKP55.5 and HKP43.7 were stably overexpressed in CM, KF and PO. Temperature switching from 35°C to 8°C upregulated HKP43.4, HKP54.6, CIP14.1 and HKP19.9 for all the cultivars. The recovery process 24h subsequent to this archetype switching was governed by overexpression of small(s)HSPs of about 25.4KD-14.1KD, HKP58.7 and HKP43.5 for all cultivars. Results suggest crosstalk protection for this paradigm-shift in temperature is chiefly conferred by isoforms of constitutively expressed HKPs, CIP19.9 and CIP14.1 in S. tuberosum L. Explicitly, this differential proteome change within 22h signify HKPs may not participate in thermotolerance as HSPs, but participate in cold acclimation as CIPs, recovery as sHSPs and even switch-off during heat-stress in some cultivars as depicted in GS.

Study of phycocyanin production from Spirulina platensis under different light spectra

The aim of this work was to investigate the production of phycocyanin by Spirulina platensis under different spectra of light. The dependent variables evaluated were the amount of phycocyanin obtained and its purity, demonstrating that there might be a restructuring of phycobilisomes, especially when the culture was subjected to red light, which increased the purity level up to 33 percent with a reduction of 16 percent in phycocyanin content, but with higher photosynthetic efficiency compared to natural light.

Instantaneous and historical temperature effects on a-pinene emissions in Pinus halepensis and Quercus ilex.

We compared the role of instantaneous temperature and temperature history in the determination of a-pinene emissions in Mediterranean conifer Pinus halepensis that stores monoterpenes in resin ducts, and in Mediterranean broad-leaved evergreen Quercus ilex that lacks such specialized storage structures. In both species, a-pinene emission rates (E) exhibited a significant exponential correlation with leaf temperature and the rates of photosynthetic electron transport (JCO 2+O 2) started to decrease after an optimum at approximately 35oC. However, there was a higher dependence of E on mean temperature of previous days than on mean temperature of current day for P. halepensis but not for Q. ilex. JCO 2+O 2 showed a maximum relationship to mean temperature of previous 3 and 5 days for P. halepensis and Q. ilex respectively. We conclude that although the best correlation of emission rates were found for instantaneous foliar temperatures, the effect of accumulated previous temperature conditions should also be considered in models of monoterpene emission, especially for terpene storing species.

Cultivo del camarón marino Litopenaeus Vannamei (Boone, 1931) En agua dulce / Culture of Marine Shrimp Litopenaeus vannamei (BOONE, 1931) in Freshwater

El cultivo del camarón marino Litopenaeus vannamei (Boone, 1931) es el rubro más importante de la acuicultura venezolana. Hasta el año 2005, su producción por hectárea en Venezuela era una de las más altas en Latinoamérica. El éxito residía en parte, en la domesticación de la especie y el haber cerrado el ciclo biológico, lo cual le permitió al país mantenerse por más de dos décadas, libre de las enfermedades virales de impacto severo como Taura y Mancha Blanca. Sin embargo, en el año 2005 se confirmó la presencia del virus del Taura, que afectó un 67% del total de granjas en los estados Zulia, Falcón y Nueva Esparta. Las enfermedades han motivado a los camaronicultores a buscar alternativas, dentro de las cuales se encuentra el cultivo de camarón marino en agua dulce. Por esta razón, este trabajo tuvo como objetivo el cultivo de camarón (L. vannamei) en agua dulce en Paraguaná, estado Falcón, Venezuela. Las postlarvas (Pls), fueron sembradas en un estanque de 969 m²de superficie. Antes de iniciar el ciclo de cultivo, se analizaron muestras de agua y de los suelos para garantizar que los parámetros recomendados para el cultivo de L. vannamei en agua dulce se cumplieran. Las Pls provenientes de un programa de mejoramiento genético fueron sometidas a un período de aclimatación y adaptación al agua dulce durante 58,5 horas. Obtenida la aclimatación se procedió a la siembra de las mismas a una densidad de 42 Pls/m². Durante el cultivo se registraron los parámetros físico-químicos (oxígeno disuelto, salinidad y temperatura). La dieta de los camarones consistió en un alimento balanceado peletizado K-maron 35®. El porcentaje de supervivencia, peso promedio, crecimiento semanal promedio, talla promedio, factor de conversión alimenticia y productividad se registraron mediante muestreos mensuales. Para el análisis de datos se empleó estadística descriptiva. El cultivo tuvo una duración de 94 días y se registraron los siguientes valores de producción: 65,19% de supervivencia, 10,66 g. de peso promedio, 1,01:1 de factor de conversión alimenticia y un rendimiento de 2.579,98 kg/ha/ciclo. Los resultados demuestran la factibilidad de este tipo de cultivo como una nueva alternativa de producción acuícola para los pequeños-medianos productores en la Península de Paraguaná-Falcón, Venezuela.

Culture of L. vannamei marine shrimp is very important to Venezuelan aquaculture. Until 2005, Venezuelan production by hectare was one of the highest in Latin America. Part of the industry success was built upon domestication of the species and selection of favorable traits and to work under closed cycle conditions, which have led to the possibility to stay free -for more than two decades- of severe viral diseases such as Taura and White Spot virus. However, by 2005 Taura virus was confirmed affecting a total of 67% farms in Zulia, Falcón and Nueva Esparta States. Epidemic diseases have lead to farmers to look for new alternatives, one of which is the culture of marine shrimp in inland low-salinity water. The aim of this present study was to culture L. vannamei marine shrimp in inland low-salinity water in Paraguana, Falcon State, Venezuela. Postlarvae at PL12 stage, were cultured in a 969 m2 pond. Before culturing, samples of water and soils were analyzed to accomplish recommended culture parameters for L. vannamei in low-salinity conditions. Postlarvae studied came from a genetic program and were acclimated by reducing salinity to 4 ppm through 58.5 hours. Once acclimation was reached, postlarvae were stocked at a density of 42 PLs/m2. Physical and chemical parameters were registered during culture (dissolved oxygen, salinity and temperature). A pellet dry-diet K-maron 35® was given as diet. Survival percentage, average weight, growth rate (g/week), total average length, feed conversion rate and productivity were evaluated through monthly sampling. Data were analyzed through descriptive statistics. L. vannamei marine shrimp was cultured during 94 days and the following production data was registered: 65.19% survival, 10.66 gr. average weight, feed conversion factor of 1.01:1 and a productivity level of 2,579.98 kg/ha/cycle. Results show this type of culture is highly feasible and it might become a new alternative for the small-medium local agriculture producers of Paraguaná-Falcón, Venezuela.

NaCl pretreatment alleviates salt stress by enhancement of antioxidant defense system and osmolyte accumulation in mungbean (Vigna radiata L. Wilczek).

Enhancement of salt (NaCl) tolerance by pretreatment with sublethal dose (50 mM) of NaCl was investigated in V. radiata seedlings. NaCl stress caused drastic effects on roots compared to shoots. Accompanying reductions in length, number of root hairs and branches, roots became stout, brittle and brown in color. Salt stress caused gradual reduction in chlorophyll, carotenoid pigment contents and chlorophyll fluorescence intensity also. Superoxide dismutase and catechol peroxidase activities increased under stress in both roots and leaves. But catalase activity showed an increase in roots and decrease in leaves. In these seedlings, the oxidative stress has been observed under salinity stress and the level of proline, H2O2 and malondialdehyde content were increased. But pretreatment with sublethal dose of NaCl was able to overcome the adverse effects of stress imposed by NaCl to variable extents by increasing growth and photosynthetic pigments of the seedlings, modifying the activities of antioxidant enzymes, reducing malondialdehyde and H2O2 content and increasing accumulation of osmolytes like proline. Thus, mungbean plants can acclimate to lethal level of salinity by pretreatment with sublethal level of NaCl, improving their health and production under saline condition.