Turbulence Unsteadiness Drives Extreme Clustering.

We show that the unsteadiness of turbulence has a drastic effect on turbulence parameters and in particle cluster formation. To this end we use direct numerical simulations of particle laden flows with a steady forcing that generates an unsteady large-scale flow. Particle clustering correlates with the instantaneous Taylor-based flow Reynolds number, and anticorrelates with its instantaneous turbulent energy dissipation constant. A dimensional argument for these correlations is presented. In natural flows, unsteadiness can result in extreme particle clustering, which is stronger than the clustering expected from averaged inertial turbulence effects.

Global phylogenomic assessment of Leptoseris and Agaricia reveals substantial undescribed diversity at mesophotic depths.

BACKGROUND: Mesophotic coral communities are increasingly gaining attention for the unique biological diversity they host, exemplified by the numerous mesophotic fish species that continue to be discovered. In contrast, many of the photosynthetic scleractinian corals observed at mesophotic depths are assumed to be depth-generalists, with very few species characterised as mesophotic-specialists. This presumed lack of a specialised community remains largely untested, as phylogenetic studies on corals have rarely included mesophotic samples and have long suffered from resolution issues associated with traditional sequence markers. RESULTS: Here, we used reduced-representation genome sequencing to conduct a phylogenomic assessment of the two dominant mesophotic genera of plating corals in the Indo-Pacific and Western Atlantic, respectively, Leptoseris and Agaricia. While these genome-wide phylogenies broadly corroborated the morphological taxonomy, they also exposed deep divergences within the two genera and undescribed diversity across the current taxonomic species. Five of the eight focal species consisted of at least two sympatric and genetically distinct lineages, which were consistently detected across different methods. CONCLUSIONS: The repeated observation of genetically divergent lineages associated with mesophotic depths highlights that there may be many more mesophotic-specialist coral species than currently acknowledged and that an urgent assessment of this largely unstudied biological diversity is warranted.

Cleaning interactions by gobies on a tropical eastern Pacific coral reef.

The present study describes the cleaning interactions among species of cleaner gobies Tigrigobius spp. and Elacatinus puncticulatus (family Gobiidae) and the client fish species they clean in a coral reef of Gorgona Island, Colombia. In 419 cleaning events, we observed 27 species acting as clients of Tigrigobius spp., whereas only nine were clients of E. puncticulatus. Paranthias colonus and Cephalopholis panamensis were the species most commonly cleaned by Tigrigobius spp., while Ophioblennius steindachneri and Stegastes acalpulcoensis were the clients most commonly cleaned by E. puncticulatus. The abundance (but not the body size) of clients was an important variable predicting the cleaning frequency observed for clients of Tigrigobius spp., but this was not the case for clients of E. puncticulatus. Additionally, Tigrigobius spp. preferred cleaning planktivores, sessile invertebrate feeders and territorial herbivores (Ivlev's index >0·15), whereas E. puncticulatus did not exhibit any preference. We observed two major peaks of cleaning activity for Tigrigobius spp., one in the early morning and another one in the late afternoon. These results suggest that Tigrigobius spp. is a specialized cleaner goby, whereas E. puncticulatus is a facultative cleaner that cleans sporadically.

Conceptual basis for an integrated system for the management of a protected area. Examples from its application in a mediterranean area.

Improving the efficiency of management in protected areas is imperative in a generalized context of limited conservation budgets. However, this is overlooked due to flaws in problem definition, general disregard for cost information, and a lack of suitable tools for measuring costs and management quality. This study describes an innovative methodological framework, implemented in the web application SIGEIN, focused on maximizing the quality of management against its costs, establishing an explicit justification for any decision. The tool integrates, with this aim, a procedure for prioritizing management objects according to a conservation value, modified by a functional criterion; a project management module; and a module for management of continuous assessment. This appraisal associates the relevance of the conservation targets, the efficacy of the methods employed, both resource and personnel investments, and the resulting costs. Preliminary results of a prototypical SIGEIN application on the Site of Community Importance Chafarinas Islands are included.

SARC-F and SARC-CalF Scores as Mortality Risk Factors in Older Men with Cancer: A Longitudinal Study from Peru.

OBJECTIVES: We aimed to evaluate the role of SARC-F and SARC-CalF scores as risk factors for mortality in adults over 60 years of age with cancer of the Centro Médico Naval (CEMENA) in Callao, Peru during 2012-2015. METHODS: We performed a secondary analysis of data from a prospective cohort carried out from September 2012 to February 2013 in the Geriatrics Department of CEMENA. The outcome variable was mortality at two years of follow-up, while the exposure variable was the risk of sarcopenia assessed using the SARC-F and SARC-CalF scales. We carried out Cox proportional-hazards models to assess the role of SARC-F and SARC-CalF scores as risk factors for mortality. We estimated crude (cHR) and adjusted (aHR) hazard ratios (HR) with their respective 95% confidence intervals (95%CI). Likewise, we calculated the area under the curve (AUC) of both exposure variables in relation to mortality. RESULTS: We analyzed data from 922 elderly men with cancer; 43.1% (n=397) were between 60 and 70 years old. 21.5% (n=198) and 45.7% (n=421) were at risk of sarcopenia according to SARC-F and SARC-CalF, respectively, while the incidence of mortality was 22.9% (n=211). In the adjusted Cox regression model, we found that the risk of sarcopenia measured by SARC-F (aHR=2.51; 95%CI: 1.40-2.77) and SARC-CalF (aHR=2.04; 95%CI: 1.55-4.02) was associated with a higher risk of death in older men with cancer. In the diagnostic performance analysis, we found that the AUC for mortality prediction was 0.71 (95%CI: 0.68-0.75) for SARC-F and 0.80 (95%CI: 0.78-0.82) for SARC-CalF. CONCLUSIONS: The risk of sarcopenia evaluated by SARC-F and SARC-CalF scores was associated with an increased risk of mortality in older men with cancer. Both scales proved to be useful and accessible instruments for the identification of groups at risk of mortality.

Unilateral Lichtenstein tension-free mesh hernia repair and testicular perfusion: a prospective control study.

PURPOSE: Compare testicular perfusion between the herniated and the healthy side pre- and post-surgery. MATERIALS AND METHODS: Our study was done on patients with unilateral inguinal hernia. A Doppler ultrasound study was performed in the healthy and herniated side before surgery and 3 months after it. RESULTS: 31 patients were included, 74.2% on the right and 25.8% on the left side. When comparing the pre-surgical values of testicular resistance index from the healthy side with those on the herniated side, there was a significant difference at the spermatic cord levels (0.73 ± 0.11 and 0.81 ± 0.13, p = 0.018) and the extra-testicular level (0.66 ± 0.92 and 0.74 ± 0.10, p = 0.032), but a significant difference was not present at the intra-testicular level (0.62 ± 0.07 and 0.65 ± 0.08). Three months after the surgery, there were no statistically significant differences at any of the levels studied. CONCLUSION: There are no intra-testicular perfusion differences caused by the presence of hernia, nor during post-surgery.

Correlation between formamidopyrimidine DNA glycosylase (Fpg)-sensitive sites determined by a comet assay, increased MDA, and decreased glutathione during long exposure to thinner inhalation.

Thinner inhalation causes toxic effects in a variety of organs, principally in the central nervous system. Some studies have shown oxidative stress effects of thinner inhalation, such as: activation of free radical processes, decrease of antioxidants, and oxidation products of proteins and lipids but not of DNA. The aim of this study is to investigate the effect of thinner inhalation on DNA. We used the comet assay in conjunction with the enzyme formamidopyrimidine glycoslyase (Fpg). Our results show a significant increase in Fpg-sensitive sites in DNA of lymphocytes from rats exposed to thinner fumes compared to lymphocytes from control rats (p < 0.05). Moreover, DNA damage detected with Fpg shows a high correlation with increased malondialdehyde (MDA) and decreased glutathione (GSH), two widely used biomarkers of oxidative stress. The most abundant base oxidation product found in DNA is 8-oxoguanine; it is the main substrate of Fpg and the most commonly used biomarker for oxidative DNA damage. This suggests that oxidative DNA damage is at least partly responsible for the DNA damage detected by Fpg. We propose the comet assay in combination with Fpg as a sensitive biomarker to monitor exposure to thinner inhalation. Limitations of this method are discussed.

Determining the variability in O(2) saturation measurements in devices of the "Dr. Guillermo Rawson" hospital.

Measurement of oxygen saturation is a noninvasive monitoring method that has had a major impact on patient care in both emergency and ambulatory situations. It is an important parameter in neonatology field, especially in newborn preterm births, and in anesthetic and surgical procedures.

Mid-domain models of species richness gradients: assumptions, methods and evidence.

Patterns of species richness along latitudinal, elevational and depth gradients often exhibit a mid-gradient peak. Similar patterns with a mid-domain peak in richness are produced, as a result of geometric constraints on species distributions, by models that randomize species range size and placement over a bounded gradient. Proponents of these so-called mid-domain models argue that they provide an appropriate null hypothesis for examining species richness patterns along spatial gradients. Furthermore, some claim that because these models seem to explain a large proportion of the large-scale spatial variation in richness, geometric constraints on species distribution are in fact the cause of these patterns. A critical examination of model assumptions reveals that some are unrealistic, conceptually flawed or internally inconsistent. Additionally, tests of mid-domain models have suffered from methodological deficiencies derived from arbitrariness and circularity in the definition of domain boundaries, collapsing two-dimensional (2-D) patterns into a single dimension (1-D), and the use of interpolated ranges, all of which can bias test results in favour of the models. Tests have also been statistically naive by using fairly insensitive measures of deviation between observed and predicted patterns and ignoring the increased probability of Type I error that can result in analyses of spatially autocorrelated data. In spite of this, a review of the empirical evidence indicates that most studies do not show a high degree of concordance between observed and predicted species richness patterns, particularly in 2-D. Additionally, spatial patterns of variation in range size and species turnover do not unequivocally support mid-domain models. Thus, the models do not adequately describe observed species richness gradients and thus fail to explain them. Although mid-domain models have served a useful purpose in drawing attention to the need to clarify the null expectation in the study of species richness gradients, their use appears to be severely limited by difficulties associated with the treatment of ranges, boundary definitions and a lack of clarity regarding the extent to which the observed data should be used to generate the null patterns.

[Acute appendicitis and pregnancy; experience at Hospital Espanõl of Mexico]. / Apendicitis aguda y embarazo; experiencia en el Hospital Español de México.

Acute appendicitis the most common surgical complication during pregnancy. The diagnosis is difficult and requires an urgent surgical treatment. The basic objective of this article was to determine the clinic profile of this association. We review the cases with acute appendicitis and pregnancy presented since January 1990 to December 1996 in our hospital. We found 17 cases, with an average age of 28.6 years. Of this 17 cases 12 were truly appendicitis. The time between the onset of the first symptom to the laparotomy was of 43.25 hours. The natural history of the appendicitis is not modified by the presence of a pregnancy. Abdominal pain remains as the clue symptom and was present in 100% of the patients. Finally an early diagnosis and treatment allows a reduction in the maternal fetal mortality.

Concentraciones de Vitamina D en niños y adolescentes con enfermedad celíaca / Vitamin D concentrations in children and adolescents with celiac disease

INTRODUCCIÓN: En celíacos la ingesta de gluten provoca una lesión inflamatoria de origen autoinmune que causa un daño progresivo de las vellosidades del intestino delgado, comprometiendo la absorción de nutrientes y posible daño a otros órganos. OBJETIVO: Determinar las concentraciones plasmáticas de 25-hidroxivitamina D (25OHD) en niños y adolescentes chilenos con enfermedad celíaca. PACIENTES Y MÉTODO: Estudio descriptivo de corte transversal. Participaron 16 pacientes pediátricos de ambos sexos, diagnosticados con enfermedad celíaca. Se determinó antecedentes ge nerales, estado nutricional y parámetros bioquímicos. Las concentraciones plasmáticas de 25OHD se clasificaron como suficientes cuando estaban entre 30-100 ng/ml, insuficiente (20-29 ng/ml) y deficiente (< 20 ng/ml). RESULTADOS: La edad de los pacientes estaba comprendida entre 5 y 18 edad (edad: 11 ± 4 años). De los participantes 4 de 16 presentaron concentraciones normales de 25OHD, 8 insuficiente y 1 deficiente. Según IMC, 11 tenían estado nutricional normal, 4 sobrepeso y 1 obesidad. El diagnóstico de la talla mostró 7 de 16 casos de talla baja y normal baja. Al relacionar las concentraciones de 25OHD con estado nutricional, los parámetros deficientes e insuficientes se concentraron en 9 pacientes con estado nutricional normal, 2 con sobrepeso y 1 con obesidad. Se realizaron asociaciones entre las concentraciones de 25OHD y todas las variables estudiadas y no se encontró ninguna asociación significativa. CONCLUSIÓN: Se encontró una alta frecuencia de insuficiencia y deficiencia de 25OHD en el grupo de niños y adolescentes chilenos con enfermedad celíaca.

INTRODUCTION: In children with celiac disease, gluten intake causes an autoimmune, inflammatory and progressive lesion of the small intestine villi, compromising the absorption of nutrients and pos sible damage to others organs. OBJECTIVE: To determine plasma 25-hydroxyvitamin D [25(OH)D] concentrations in Chilean child and adolescents with celiac disease. PATIENTS AND METHOD: A descriptive cross-sectional study was carried out in which 16 pediatric patients of both genders diagnosed with celiac disease participated. General background, nutritional status and biochemical parameters were determined. Plasma 25(OH)D concentrations were classified as sufficient between 30-100 ng/ ml, insufficient between 20-30 ng/ml and deficient as <20 ng/ml. RESULTS: The age of the patients was between 5 and 18 years (age: 11 ± 4 years). Four out of 16 participants had normal 25(OH)D concentrations, eight had insufficient concentrations and one had deficient concentrations. Accor ding to BMI, 11 patients had normal nutritional status, four were overweight and one was obese. In relation to height, seven out of 16 cases presented short stature and normal-low height. Associating 25(OH)D concentrations to nutritional status, nine patients with normal nutritional status, two with overweight and one with obesity presented deficient and insufficient parameters. No significant asso ciations were found between 25(OH)D concentrations and all studied variables. CONCLUSION: A high frequency of insufficiency and deficiency of 25(OH)D was found in the group of Chilean children and adolescents with celiac disease.

Riesgo de trastorno de la conducta alimentaria en adolescentes chilenos de diferentes tipos de establecimientos educacionales / Risk of eating disorders in Chilean adolescents of different types educational establishments

Los trastornos de la conducta alimentaria (TCA) son patologías de salud mental complejas, caracterizados por una alteración persistente del comer o del comportamiento relacionado con la alimentación. El objetivo de este estudio fue determinar el riesgo de TCA en adolescentes de diferentes tipos de establecimientos educacionales de la ciudad de Concepción, Chile. La muestra fue constituida por estudiantes de 7mo año básico a 4to año de enseñanza media, cuyo rango de edad fue de 13 a 18 años, pertenecientes a establecimientos educacionales municipalizados, particular subvencionados y particular, de la ciudad de Concepción. Para determinar riesgo de TCA, se empleó el instrumento de Test de Actitudes Alimentarias (EAT-40), junto a ello se realizaron mediciones de peso y talla para calcular el Índice de Masa Corporal. La muestra final comprendió 1056 estudiantes, de los cuales 37,5% eran hombres y 62,5% eran mujeres. El riesgo de desarrollar un TAC fue de 16,1%, siendo mayor en mujeres (21,8%) en relación con los hombres (6,6%) (p<0.001). Se evidenció mayor riesgo de TCA en mujeres con estado nutricional con sobrepeso (27,7%) y en hombres con estado nutricional de obesidad (14,7%). Al evaluar riesgo de TCA por tipo de establecimientos educacionales, se observan diferencias, pero sin resultados significativos (p 0,2008). Es relevante contar con políticas públicas que permitan abordar y acompañar a los adolescentes en riesgo de desarrollar un TCA(AU)

Eating disorders are complex mental health illnesses, characterized by irregular eating habits or behavior related to food. The purpose of this study was to determine the risk of eating disorders in adolescents from different educational establishments in the city of Concepción. The sample was constituted by students of seventh grade of basic education to fourth year of secondary, whose age range was from 13 to 18, belonging to public, subsidized and private educational establishments in the city of Concepción. To determine the risk of eating disorder, the Eating Attitudes (EAT-40) was used, and weight and height were measured to calculate body mass index. The final sample was composed of 1056 students, of which 37,5% were men and 62,5% women. The risk of developing an eating disorder was 16,1%, being higher in women (21,8%) in relation to men (6,6%) (p <0,001). It was demonstrated a higher risk of TCA in overweight women (27, 7%) and men with obesity (14, 7%). In assessing risks of TCA per type of educational establishments there were some differences but without significant results (p 0, 2008). It is essential to have public policies that allow the approach and accompany adolescents at risk of developing a disorder of eating behavior(AU)

[Not Available]. / Meningoencefalitis tuberculosa con quistes aracnoideos medulares y siringomielia aguda.

TITLE: Meningoencefalitis tuberculosa con quistes aracnoideos medulares y siringomielia aguda.

Fallout radionuclide-based techniques for assessing the impact of soil conservation measures on erosion control and soil quality: an overview of the main lessons learnt under an FAO/IAEA Coordinated Research Project.

This paper summarizes key findings and identifies the main lessons learnt from a 5-year (2002-2008) coordinated research project (CRP) on "Assessing the effectiveness of soil conservation measures for sustainable watershed management and crop production using fallout radionuclides" (D1.50.08), organized and funded by the International Atomic Energy Agency through the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. The project brought together nineteen participants, from Australia, Austria, Brazil, Canada, Chile, China, Japan, Morocco, Pakistan, Poland, Romania, Russian Federation, Turkey, United Kingdom, United States of America and Vietnam, involved in the use of nuclear techniques and, more particularly, fallout radionuclides (FRN) to assess the relative impacts of different soil conservation measures on soil erosion and land productivity. The overall objective of the CRP was to develop improved land use and management strategies for sustainable watershed management through effective soil erosion control practices, by the use of ¹³7Cs (half-life of 30.2 years), ²¹°Pb(ex) (half-life of 22.3 years) and 7Be (half-life of 53.4 days) for measuring soil erosion over several spatial and temporal scales. The environmental conditions under which the different research teams applied the tools based on the use of fallout radionuclides varied considerably--a variety of climates, soils, topographies and land uses. Nevertheless, the achievements of the CRP, as reflected in this overview paper, demonstrate that fallout radionuclide-based techniques are powerful tools to assess soil erosion/deposition at several spatial and temporal scales in a wide range of environments, and offer potential to monitor soil quality. The success of the CRP has stimulated an interest in many IAEA Member States in the use of these methodologies to identify factors and practices that can enhance sustainable agriculture and minimize land degradation.

Bile retinoids imprint intestinal CD103+ dendritic cells with the ability to generate gut-tropic T cells.

Small intestinal lamina propria (SI-LP) CD103(+) dendritic cells (DCs) are imprinted with an ability to metabolize vitamin A (retinol), a property underlying their enhanced capacity to induce the gut-homing receptors CC chemokine receptor-9 and α4ß7 on responding T cells. In this study, we demonstrate that imprinting of CD103(+) DCs is itself critically dependent on vitamin A and occurs locally within the small intestine (SI). The major vitamin A metabolite retinoic acid (RA) induced retinol-metabolizing activity in DCs both in vitro and in vivo, suggesting a direct role for RA in this process. Consistent with this, SI-LP CD103(+) DCs constitutively received RA signals in vivo at significantly higher levels than did colonic CD103(+) DCs. Remarkably, SI CD103(+) DCs remained imprinted in mice depleted of dietary but not of systemic retinol. We found that bile contained high levels of retinol, induced RA receptor-dependent retinol-metabolizing activity in bone marrow-derived DCs, and imprinted these cells with the ability to generate gut-tropic T cells. Taken together, these results suggest a novel and unexpected role for bile in SI-LP CD103(+) DC imprinting.

Evaluación nutricional y adherencia a la dieta mediterránea de adolescentes chilenos que residen en hogares de familias hospedadoras / Nutritional assessment and adherence to the mediterranean diet of chilean adolescents residing in host families

El estilo de vida de los adolescentes puede conducir a hábitos y preferencias alimentarias poco saludables que promueven al sobrepeso y la obesidad, siendo un factor de riesgo presente y futuro para el desarrollo de enfermedades crónicas. La dieta mediterránea es uno de los modelos más saludables de alimentación por su asociación a una mayor esperanza de vida y a su efecto protector de las enfermedades crónicas. El objetivo de este estudio fue determinar el estado nutricional y la adherencia a una dieta mediterránea de un grupo de adolescentes chilenos que residen en hogares de familias hospedadoras. El diseño del estudio fue descriptivo y de corte transversal. Participaron 40 adolescentes de ambos sexos y de edad entre 14 y 22 años, que por motivos de estudio se trasladan a la ciudad para vivir en hogares de familias hospedadoras. Para la evaluación del estado nutricional se realizaron mediciones antropométricas y se aplicó el test KIDMED para evaluar el grado de adherencia a la dieta mediterránea. Los resultados indicaron que 50% de los adolescentes estudiados presentaban malnutrición por exceso y una baja adherencia a la dieta mediterránea. Se concluye que la mayoría de los adolescentes estudiados presentan malnutrición por exceso; y su alimentación se aleja de las recomendaciones de una alimentación saludable y protectora como lo es la dieta mediterránea.

The lifestyle of adolescents can lead to eating habits and preferences least healthy that can cause overweight and obesity, making this a present and future risk factor for the develop-ment of chronic diseases. The Mediterranean diet is one of the healthiest eating models for its association to a greater hope of life and protection of chronic diseases. The objective of this study was to determine the nutritional status and adherence to the Mediterranean diet of a group of Chilean adolescents that reside in homes of housing families. The design of the study was descriptive crossectional. Participants were 40 adolescents of both sexes between 14 and 22 years of age, who for study moved to the city to live in homes of host families. For the evaluation of the nutritional status, anthropometric measurements were made and the KIDMED test was applied to evaluate the grade of adherence to the mediterranean diet. The results indicate that 50% of the adolescents in the study present ed malnutrition due to excess and low adherence to the Mediterranean diet. In conclusion most adolescents present malnutrition for excess; and their feeding stride far from the recommendations of a healthy and protective diet as the Mediterranean diet.

Retinoic acid receptor signaling levels and antigen dose regulate gut homing receptor expression on CD8+ T cells.

Recent studies have highlighted a central role for intestinal dendritic cells (DCs) and vitamin A metabolite retinoic acid (RA) in the generation of alpha4beta7(+) CCR9(+)"gut tropic" effector T cells. Here, using RA-responsive element reporter mice, we demonstrate that both splenic and mesenteric lymph node (MLN) DCs enhanced retinoic acid receptor (RAR) signaling in CD8(+) T cells; however, only a subset of MLN DCs, expressing the integrin alpha-chain CD103, induced an early RAR signal that is required for efficient CCR9 induction. MLN-primed CD8(+) T cells also received enhanced RAR-dependent signals compared with splenic-primed CD8(+) T cells in vivo. Further DC-mediated induction of gut homing receptors was inhibited at a high antigen dose without influencing RAR signaling events, and resulted in less efficient CD8(+) T-cell entry into the small intestinal mucosa. These results highlight a complex interplay between antigen dose and DC subset-induced RAR signaling events in the generation of tissue tropic effector T-cell subsets.

Somatic embryogenesis from Lycopersicon peruvianum leaf mesophyll protoplasts.

One to five percent of Lycopersicon peruvianum (L.) Mill. leaf mesophyll protoplasts undergo cell division and concomitant organization to form embryogenic-like structures when cultured in Murashige and Skoog medium (1962) containing 3% sucrose, 9% mannitol, 1.0 mg/l kinetin (K) and 1.0 mg/l naphthalene acetic acid (NAA) at pH 5.6-5.8 (medium A). These embryogenic structures, after passing through developmental stages similar to those observed in zygotic embryogeny, are capable of forming shoots on hormone-free medium A. In medium B, wherein 0.5 mg/l of 2,4-dichlorophenoxyacetic (2,4-D) replaced the hormones (K and NAA), embryogenic structures did not develop. However, callus originating in medium B retained morphogenetic capacity as was evidenced by subsequent shoot regeneration when they were transferred to medium A with K and NAA replaced by 1.0 mg/l zeatin (Z). The potential value of incorporating this regeneration trait into Lycopersicon species and cultivated lines for use in tissue culture programs is discussed.

Position of anthers at plating and its influence on anther callusing in rice.

Effect of position of anthers at plating in relation to their ability to form callus was studied in rice (Oryza sativa var. Taipei 309). Among the callusing anthers, about 60% were those positioned on edge with one lobe in contact with the medium while the rest were flat with both lobes touching the medium. Anthers in both positions produced calli and regenerated green plants.