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Introducción. La diabetes mellitus es una de las enfermedades crónicas con mayor prevalencia en la población pediátrica y juvenil, con efectos en la calidad de vida de los pacientes. Objetivo. Evaluar la calidad de vida de una población pediátrica menor de 18 años con diagnóstico de diabetes de tipo 1, de dos instituciones pediátricas de la ciudad de Bogotá. Materiales y métodos. Se recolectaron los datos sociodemográficos, y se emplearon la versión validada en español del cuestionario PedsQL 4.0™ y el módulo 3.2 sobre diabetes. Los datos se procesaron en el software estadístico STATA 17™. Resultados. Con el puntaje global del módulo 3.2 sobre diabetes, de la versión validada del PedsQL™, se evaluó la correlación entre los valores de la hemoglobina A1c (HbA1c) y los del cuestionario. Los pacientes con valores por debajo del 9 % de HbA1c presentaron una mejor calidad de vida relacionada con la salud, mientras que, en el grupo con HbA1c mayor de 9 %, se observó una baja percepción de calidad de vida (p=0,025). En cuanto el tipo de terapia y la relación con los dominios del PedsQL™ 3.2, versión diabetes, los pacientes que utilizaban la bomba de insulina o microinfusor presentaban mejor puntaje en los dominios barreras, cumplimiento, preocupación y comunicación, y en el puntaje global, respecto a quienes usaban múltiples inyecciones de insulina como tratamiento (p=0,0363). Conclusiones. En nuestros pacientes, un mejor control metabólico (medido por el valor de HbA1c) y el uso de microinfusora contribuyen a una percepción de mejor calidad de vida.

Congenital hypoaldosteronism is a rare autosomal recessive or dominant endocrinopathy with variable penetrance, secondary to primary defects in aldosterone synthesis that could lead to hypovolemia, hyponatremia, hyperkalemia, failure to thrive, microcephaly, seizures, neurodevelopmental delay, or hearing loss. We present the case of a Colombian patient with congenital hypoaldosteronism, who owns two variants in the CPY11B2 gene, and a heterozygous pathogenic variant for nonclassical congenital adrenal hyperplasia. However, the patient missed follow-up and treatment for 6 years. At the age of 7 years, he resumed medical follow-up with laboratory findings of hyperreninemia and hypoaldosteronism, as well as clinical findings of strabismus, left mixed hyperacusis, and pathological short stature (−4.3 SD). Therefore, a trial of fludrocortisone therapy was started with subsequent improvement in renin levels, weight gain, and growth velocity. After 10 months of the start of the medication, he presented hypertension. There is no literature about the late treatment of this condition for pathological short stature.

Climate change challenges modern agriculture to develop alternative and eco-friendly solutions to alleviate abiotic and/or biotic stresses. The use of soil microbiomes from extreme environments opens new avenues to discover novel microorganisms and microbial functions to protect plants. In this study we confirm the ability of a bioinoculant, generated by natural engineering, to promote host development under water stress. Microbiome engineering was mediated through three factors i) Antarctic soil donation, ii) water deficit and iii) multigenerational tomato host selection. We revealed that tomato plants growing in soils supplemented with Antarctic microbiota were tolerant to water deficit stress after 10 generations. A clear increase in tomato seedling tolerance against water deficit stress was observed in all soils over generations of Host Mediated Microbiome Engineering, being Fildes mixture the most representatives, which was evidenced by an increased survival time, plant stress index, biomass accumulation, and decreased leaf proline content. Microbial community analysis using 16s rRNA gene amplicon sequencing data suggested a microbiome restructuring that could be associated with increased tolerance of water deficit. Additionally, the results showed a significant increase in the relative abundance of Candidatus Nitrosocosmicus and Bacillus spp. which could be key taxa associated with the observed tolerance improvement. We proposed that in situ microbiota engineering through the evolution of three factors (long-standing extreme climate adaption and host and stress selection) could represent a promising strategy for novel generation of microbial inoculants.

The present study examined the biosynthesis and characterization of selenium nanoparticles (SeNPs) using two contrasting endophytic selenobacteria, one Gram-positive (Bacillus sp. E5 identified as Bacillus paranthracis) and one Gram-negative (Enterobacter sp. EC5.2 identified as Enterobacter ludwigi), for further use as biofortifying agents and/or for other biotechnological purposes. We demonstrated that, upon regulating culture conditions and selenite exposure time, both strains were suitable “cell factories” for producing SeNPs (B-SeNPs from B. paranthracis and E-SeNPs from E. ludwigii) with different properties. Briefly, dynamic light scattering (DLS), transmission electron microscopy (TEM), and atomic force microscopy (AFM) studies revealed that intracellular E-SeNPs (56.23 ± 4.85 nm) were smaller in diameter than B-SeNPs (83.44 ± 2.90 nm) and that both formulations were located in the surrounding medium or bound to the cell wall. AFM images indicated the absence of relevant variations in bacterial volume and shape and revealed the existence of layers of peptidoglycan surrounding the bacterial cell wall under the conditions of biosynthesis, particularly in the case of B. paranthracis. Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) showed that SeNPs were surrounded by the proteins, lipids, and polysaccharides of bacterial cells and that the numbers of the functional groups present in B-SeNPs were higher than in E-SeNPs. Thus, considering that these findings support the suitability of these two endophytic stains as potential biocatalysts to produce high-quality Se-based nanoparticles, our future efforts must be focused on the evaluation of their bioactivity, as well as on the determination of how the different features of each SeNP modulate their biological action and their stability.

Familial hyperchylomicronemia syndrome is a monogenic autosomal recessive disorder that causes severe and refractory hypertriglyceridemia. This uncommon condition is challenging to diagnose and treat and can lead to comorbidities such as acute pancreatitis. Although treatment options are limited in the pediatric population, strict diets and treatments approved for other dyslipidemias may be implemented in familial hyperchylomicronemia syndrome, given the lack of pharmacological interventions available. We report a 14-year-old female presented to the emergency room with abdominal pain suggestive of acute pancreatitis. Biochemical analysis revealed a triglyceride value of 4260 mg/dL. Treatment for triglyceride reduction with a strict CHILD-2 triglyceride-lowering diet, insulin infusion, fibrates, and multiple plasmapheresis were initially insufficient. Primary hypertriglyceridemia was suspected, and genetic testing identified a homozygous pathogenic variant in the lipoprotein lipase gene, diagnosing familial hyperchylomicronemia syndrome. She was discharged with a maximum dose of fibrate, statin, omega-3 fatty acids, and a restrictive diet. At her 1-month and 9-month follow-ups, her triglyceride values were 756 and 495 mg/dL, respectively, without incident complications. Familial hyperchylomicronemia syndrome is an uncommon condition with limited available literature and treatment options, especially in the pediatric population. Acute pancreatitis secondary to severe hypertriglyceridemia is a condition with a high risk of mortality which requires prompt clinical suspicion and treatment.

Diabetic ketoacidosis is a life-threatening complication associated with type 1 diabetes (T1D). Recent evidence suggests that SARS-CoV-2 could trigger diabetic ketoacidosis in type 1 diabetes susceptibility and previous insulitis; however, the data on SARS-CoV-2-infected patients with diabetic ketoacidosis as their type 1 diabetes are still limited. We report a 13-year-old Latinamerican male with symptoms and laboratory tests diagnostic of diabetic ketoacidosis and positive SARS-CoV-2 reverse transcription polymerase chain reaction, who required mild COVID-19 care management, fluid resuscitation, and insulin infusion at a regular dose, without further complications after the acute infection. Clinical/biochemical improvement allowed outpatient endocrinology follow-up with insulin therapy and continuous glucose monitoring. To our knowledge, we report the first case of diabetic ketoacidosis as the debut of type 1 diabetes in a Colombian pediatric patient with concurrent SARS-CoV-2 infection. Therefore, this report aims to contribute to the global research on SARS-CoV-2 and diabetic ketoacidosis and discuss the approach to these concomitant pathologies.

One of the most challenging aspects of long-term research based on microorganisms is the maintenance of isolates under ex situ conditions, particularly the conservation of phytopathological characteristics. Our research group has worked for more than 10 years with Gaumannomyces graminis var. tritici (Ggt), the main biotic factor affecting wheat. In this sense we preserved the microorganisms in oil overlaid. However, several strains preserved for a long time lost their pathogenicity. These strains show white and non-infective mycelia. In this sense, we hypothesized that this is attributable to low melanin content. Melanin is a natural pigment mainly involved in UV protection, desiccation, salinity, oxidation, and fungal pathogenicity. Therefore, understanding the melanin role on Ggt pathogenicity is fundamental to developing melanin activation strategies under laboratory studies. In this study, we induce melanin activation by UV-A light chamber, 320 to 400 nm (T1) and temperature changes of 30 °C, 15 °C, and 20 °C (T2). Fungal pathogenicity was evaluated by determination of blackening roots and Ggt was quantified by real-time PCR in inoculated wheat plants. Results revealed that Ggt grown under UV-A (T1) conditions showed around 40% higher melanin level with a concomitant effect on root infection (98% of blackened roots) and 4-fold more Ggt genome copy number compared with the control (non-infective mycelia) being T1, a more inductor factor compared with T2. These findings would support the role of melanin in pathogenicity in darkly pigmented fungi such as Ggt and could serve as a basis for activating pathogenicity under laboratory conditions.

From the thermal point of view, the main operational problems conventional heat exchangers of the tubular type face are the prevalence of the laminar sublayer on the surface immediately adjacent to the heat transfer surface that is responsible for low heat transfer coefficients. A passive means of disrupting this layer is using mechanical inserts known as turbulence promoters. The search for new geometries with better thermohydraulic performance has increased the number of designs available in the open literature. In sight of the large number of different options available for use in design, the selection of the right type of insert for a given application is the focus of this paper and introduces an alternative approach for the selection of turbulence promoters based on the thermal and hydraulic lengths. The approach allows for a quick comparison of the thermo-hydraulic performance in design and retrofit. It considers the effect of the magnitude of the heat transfer coefficient of the opposing stream as well as the effect of viscosity on the selection. Some turbulence promoters out of the many that have been published are used to demonstrate the methodology. This work confirms that the two conditions that result in a greater impact of the turbulence promoter on the overall heat transfer coefficient are when the tube-side presents the higher thermal resistance and when a highly viscous fluid flows through the tubes.

In the current scenario of climate change, the future of agriculture is uncertain. Climate change and climate-related disasters have a direct impact on biotic and abiotic factors that govern agroecosystems compromising the global food security. In the last decade, the advances in high throughput sequencing techniques have significantly improved our understanding about the composition, function and dynamics of plant microbiome. However, despite the microbiome have been proposed as a new platform for the next green revolution, our knowledge about the mechanisms that govern microbe-microbe and microbe-plant interactions are incipient. Currently, the adaptation of plants to environmental changes not only suggests that the plants can adapt or migrate, but also can interact with their surrounding microbial communities to alleviate different stresses by natural microbiome selection of specialized strains, phenomenon recently called “Cry for Help”. From this way, plants have been co-evolved with their microbiota adapting to local environmental conditions to ensuring the survival of the entire holobiome to improve plant fitness. Thus, the strong selective pressure of native extreme microbiomes could represent a remarkable microbial niche of plant stress-amelioration to counteract the negative effect of climate change in food crops. Currently, the microbiome engineering has recently emerged as an alternative to modify and promote positive interactions between microorganisms and plants to improve plant fitness. In the present review, we discuss the possible use of extreme microbiome to alleviate different stresses in crop plants under the current scenario of climate change.

En Colombia, actualmente no existen parámetros claros para el diagnóstico de pacientes con talla baja, ni sobre el tratamiento de esta población con hormona de crecimiento recombinante humana (somatropina), lo cual se ve favorecido por la diversidad de programas de formación de profesionales en endocrinología pediátrica. En respuesta a esta problemática se realizó el primer acuerdo colombiano de expertos en talla baja liderado por la Asociación Colegio Colombiana de Endocrinología Pediátrica (ACCEP); este trabajo contó con la participación y el aval de expertos clínicos de importantes instituciones de salud públicas y privadas del país, además de expertos metodológicos del instituto Keralty, quienes garantizaron la estandarización del uso de la somatropina. Después de realizar una minuciosa revisión de la literatura, se propone la unificación de definiciones, un algoritmo diagnóstico, los parámetros de referencia de las pruebas bioquímicas y dinámicas, una descripción de las consideraciones de uso de la somatropina para el tratamiento de las patologías con aprobación por la entidad regulatoria de medicamentos y alimentos en Colombia y, por último, un formato de consentimiento informado y de ficha técnica del medicamento.

Crop migration caused by climatic events has favored the emergence of new soilborne diseases, resulting in the colonization of new niches (emerging infectious diseases, EIDs). Soilborne pathogens are extremely persistent in the environment. This is in large part due to their ability to reside in the soil for a long time, even without a host plant, using survival several strategies. In this regard, disease-suppressive soils, characterized by a low disease incidence due to the presence of antagonist microorganisms, can be an excellent opportunity for the study mechanisms of soil-induced immunity, which can be applied in the development of a new generation of bioinoculants. Therefore, here we review the main effects of climate change on crops and pathogens, as well as the potential use of soil-suppressive microbiota as a natural source of biocontrol agents. Based on results of previous studies, we also propose a strategy for the optimization of microbiota assemblages, selected using a host-mediated approach. This process involves an increase in and prevalence of specific taxa during the transition from a conducive to a suppressive soil. This strategy could be used as a model to engineer microbiota assemblages for pathogen suppression, as well as for the reduction of abiotic stresses created due to global climate change.

The presence of fungi in pristine Antarctic soils is of particular interest because of the diversity of this microbial group. However, the extreme conditions that coexist in Antarctica produce a strong selective pressure that could lead to the evolution of novel mechanisms for stress tolerance by indigenous microorganisms. For this reason, in recent years, research on cold-adapted microorganisms has increased, driven by their potential value for applications in biotechnology. Cold-adapted fungi, in particular, have become important sources for the discovery of novel bioactive secondary metabolites and enzymes. In this study, we studied the fungal community structure of 12 soil samples from Antarctic sites, including King George Island (including Collins Glacier), Deception Island and Robert Island. Culturable fungi were isolated and described according to their morphological and phenotypical characteristics, and the richness index was compared with soil chemical properties to describe the fungal community and associated environmental parameters. We isolated 54 fungal strains belonging to the following 19 genera: Penicillium, Pseudogymnoascus, Lambertella, Cadophora, Candida, Mortierella, Oxygenales, Geomyces, Vishniacozyma, Talaromyces, Rhizopus, Antarctomyces, Cosmospora, Tetracladium, Leptosphaeria, Lecanicillium, Thelebolus, Bjerkandera and an uncultured Zygomycete. The isolated fungi were comprised of 70% Ascomycota, 10% Zygomycota, 10% Basidiomycota, 5% Deuteromycota and 5% Mucoromycota, highlighting that most strains were associated with similar genera grown in cold environments. Among the culturable strains, 55% were psychrotrophic and 45% were psychrophilic, and most were Ascomycetes occurring in their teleomorph forms. Soils from the Collins Glacier showed less species richness and greater species dominance compared with the rest of the sites, whereas samples 4, 7, and 10 (from Fildes Bay, Coppermine Peninsula and Arctowski Station, respectively) showed greater species richness and less species dominance. Species richness was related to the C/N ratio, whereas species dominance was inversely related to C and N content. Thus, the structure of the fungal community was mainly related to soil chemical parameters more than sample location and altitude.

Gaeumannomyces graminis var. tritici (Ggt) is the main soilborne factor that affects wheat production around the world. Recently we reported the occurrence of six suppressive soils in monoculture areas from indigenous “Mapuche” communities, and evidenced that the suppression relied on the biotic component of those soils. Here, we compare the rhizosphere and endosphere microbial community structure (total bacteria, actinomycetes, total fungi, and ascomycetes) of wheat plants grown in suppressive and conducive soils. Our results suggested that Ggt suppression could be mediated mostly by bacterial endophytes, rather than rhizosphere microorganisms, since the community structure was similar in all suppressive soils as compared with conducive. Interestingly, we found that despite the lower incidence of take-all disease in suppressive soils, the Ggt concentration in roots was not significantly reduced in all suppressive soils compared to those growing in conducive soil. Therefore, the disease suppression is not always related to a reduction of the pathogen biomass. Furthermore, we isolated endophytic bacteria from wheat roots growing in suppressive soils. Among them we identified Serratia spp. and Enterobacter spp. able to inhibit Ggt growth in vitro. Since the disease, but not always pathogen amount, was reduced in the suppressive soils, we propose that take all disease suppressiveness is not only related to direct antagonism to the pathogen.

Wheat production around the world is severely compromised by the occurrence of “take-all” disease, which is caused by the soil-borne pathogen Gaeumannomyces graminis var. tritici (Ggt). In this context, suppressive soils are those environments in which plants comparatively suffer less soil-borne pathogen diseases than expected, owing to native soil microorganism activities. In southern Chile, where 85% of the national cereal production takes place, several studies have suggested the existence of suppressive soils under extensive wheat cropping. Thus, this study aimed to screen Ggt-suppressive soil occurrence in 16 locations managed by indigenous “Mapuche” communities, using extensive wheat cropping for more than 10 years. Ggt growth inhibition in vitro screenings allowed the identification of nine putative suppressive soils. Six of these soils, including Andisols and Ultisols, were confirmed to be suppressive, since they reduced take-all disease in wheat plants growing under greenhouse conditions. Suppressiveness was lost upon soil sterilization, and recovered by adding 1% of the natural soil, hence confirming that suppressiveness was closely associated to the soil microbiome community composition. Our results demonstrate that long-term extensive wheat cropping, established by small Mapuche communities, can generate suppressive soils that can be used as effective microorganism sources for take-all disease biocontrol. Accordingly, suppressive soil identification and characterization are key steps for the development of environmentally-friendly and efficient biotechnological applications for soil-borne disease control.

La resistencia a la hormona tiroidea es un desorden genético autosómico dominante que afecta a 1 de cada 40,000 nacidos. Se caracteriza por una respuesta reducida de los tejidos blandos a la hormona tiroidea con incremento de niveles de tiroxina y de triyodotironina, sin inhibición de la hormona tirotropa, como consecuencia de mutaciones presentes en el receptor beta de la hormona tiroidea, particularmente en el dominio de unión a la hormona. El fenotipo clínico varía entre diferentes familias e incluso entre miembros de la misma familia. Generalmente, los individuos con Resistencia a la Hormona Tiroidea pueden presentarla de una manera variable en diferentes tejidos, debido a síntomas heterogéneos de hipotiroidismo e hipertiroidismo. Los síntomas más comunes son bocio, taquicardia, déficit de atención, alteraciones auditivas y retraso en el crecimiento óseo. Pacientes y Métodos. En este estudio se caracterizaron clínica y molecularmente dos familias colombianas con Resistencia a la Hormona Tiroidea mediante análisis clínicos y genéticos, utilizando la reacción en cadena de la polimerasa y secuenciación del gen del receptor beta de la tiroxina (TRβ). Resultados. Se identificó una nueva mutación no sinónima en el exón 8 del gen TRβ, la cual lleva al cambio de una valina por una leucina en el codón 264 (V264L). También, se identificó una mutación de novo en el exón 10 del gen TRβ que consiste en una deleción de una citosina en el nucleótido 1609 que lleva a un cambio en el marco de lectura y finalmente a un codón de parada en la posición 442 (1609delC). Conclusiones. En Colombia, no existen mutaciones reportadas hasta el momento asociadas a Resistencia a la Hormona Tiroidea. Es de resaltar que las mutaciones encontradas en Colombia son únicas de nuestro país, lo cual debe tenerse en cuenta para una correcta asesoría genética.

El síndrome de resistencia a la hormona tiroidea (RTH) es una alteración genética con herencia autosómica dominante, aunque también pueden encontrarse casos producidos por mutaciones de novo, alcanzando en total una incidencia estimada de 1 caso por cada 40000 nacidos vivos. Su principal causa son las mutaciones en el receptor Beta de la hormona tiroidea (TRB), específicamente en la región de unión a la hormona, habiéndose identificado hasta el momento más de 343 familias afectadas con el síndrome en las que han podido caracterizarse 124 mutaciones como únicas de la familia. Los individuos que padecen esta patología típicamente presentan síntomas consistentes con una disminución de la acción propia de la Hormona Tiroidea en los tejidos periféricos y otros asociados al aumento en las concentraciones plasmáticas de ésta, mostrando además en las pruebas de función tiroidea niveles persistentemente elevados de Tiroxina (T4), Triyodotironina (T3) y de sus fracciones libres, con Tirotropina (TSH, Thyroid Stimulating Hormone) normales ó ligeramente altos, anti-TPO y anti-TG negativos. No obstante, existen reportes de concurrencia del RTH con Tiroiditis crónica autoinmune como la tiroiditis de Hashimoto, estableciendo incluso una predisposición al desarrollo de esta última en los pacientes diagnosticados con RTH. Presentamos aquí la caracterización clínica y molecular del RTH en una familia colombiana demostrando que una mutación novedosa en el exón 8 del TRB, la cual denominamos V264L, es la responsable del RTH en esta familia. Adicionalmente se identificó la presencia de una tiroiditis crónica autoinmune en esta familia. Se sugiere un diagnóstico genético neonatal para los individuos de esta familia, pudiendo realizarles un seguimiento efectivo de su condición.

Summary: Aluminum (Al)-tolerant phosphobacteria enhance plant growth in acidic soils by improving Al complexing and phosphorus (P) availability. However, the impact of Al stress and P deficiency on bacterial biochemistry and physiology remains unclear. We investigated the single and mutual effects of Al stress (10 mM) and P deficiency (0.05 mM) on the proteome of three aluminum-tolerant phosphobacteria: Enterobacter sp. 198, Enterobacter sp. RJAL6, and Klebsiella sp. RCJ4. Cultivated under varying conditions, P deficiency upregulated P metabolism proteins while Al exposure downregulated iron-sulfur and heme-containing proteins and upregulated iron acquisition proteins. This demonstrated that Al influence on iron homeostasis and bacterial central metabolism. This study offers crucial insights into bacterial behavior in acidic soils, benefiting the development of bioinoculants for crops facing Al toxicity and P deficiency. This investigation marks the first proteomic study on the interaction between high Al and P deficiency in acid soils-adapted bacteria.

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Fungal biotransformation is an attractive synthetic strategy to produce highly specific compounds with chemical functionality in regions of the carbon skeleton that are not easily activated by conventional organic chemistry methods. In this work, Cladosporium antarcticum isolated from sediments of Glacier Collins in Antarctica was used to obtain novel drimane sesquiterpenoids alcohols with activity against Candida yeast from drimendiol and epidrimendiol. These compounds were produced by the high-yield reduction of polygodial and isotadeonal with NaBH4 in methanol. Cladosporium antarcticum produced two major products from drimendiol, identified as 9α-hydroxydrimendiol (1, 41.4 mg, 19.4% yield) and 3β-hydroxydrimendiol (2, 74.8 mg, 35% yield), whereas the biotransformation of epidrimendiol yielded only one product, 9β-hydroxyepidrimendiol (3, 86.6 mg, 41.6% yield). The products were purified by column chromatography and their structure elucidated by NMR and MS. The antifungal activity of compounds 1–3 was analyzed against Candida albicans, C. krusei and C. parapsilosis, showing that compound 2 has a MIC lower than 15 µg/mL against the three-pathogenic yeast. In silico studies suggest that a possible mechanism of action for the novel compounds is the inhibition of the enzyme lanosterol 14α-demethylase, affecting the ergosterol synthesis.

In the southern hemisphere, the commercial production of hazelnut has increased in recent years, with a concomitant detection of new pathogens associated with plant production, so-called emerging infectious diseases (EIDs). Gray necrosis (GN) is a hazelnut disease that causes 30% of economic losses in Europe. In this sense, we recently reported GN as an EID in Chile, the main hazelnut producer in the southern hemisphere. Therefore, control strategies are urgently required to avoid disease dissemination. In this study, the effect of boron (B) and zinc (Zn) fertilization on the incidence of GN was determined. Additionally, the community composition of microorganisms via Dendrogram Gradient Gel Electrophoresis (DGGE) was evaluated, and bacteria from internal tissue (endophytic) were isolated to study their bio-control traits under greenhouse conditions. The microbial occurrence and biocontrol ability was evaluated using MALDI-TOF/TOF. According to the results, B and Zn promote beneficial bacteria which may be able to diminish symptoms associated with GN. Thus, beneficial microorganisms, applied in combination with micronutrients, could be synergistically applied in sustainable agriculture.

Climate change directly affecting the Antarctic Peninsula has been reported to induce the successful colonization of ice-free lands by two Antarctic vascular plants (Deschampsia antarctica and Colobanthus quitensis). While studies have revealed the importance of microbiota for plant growth and stress tolerance in temperate climates, the role that plant-associated microbes play in the colonization of ice-free lands remains unknown. Consequently, we used high-throughput DNA sequence analyses to explore the composition, predicted functions, and interactive networks of plant-associated microbial communities among the rhizosphere, endosphere, and phyllosphere niches of D. antarctica and C. quitensis. Here we report a greater number of operational taxonomic units (OTUs), diversity, and richness in the microbial communities from the rhizosphere, relative to endosphere and phyllosphere. While taxonomic assignments showed greater relative abundances of Proteobacteria, Bacteroidetes, and Actinobacteria in plant niches, principal coordinate analysis revealed differences among the bacterial communities from the other compartments examined. More importantly, however, our results showed that most of OTUs were exclusively found in each plant niche. Major predicted functional groups of these microbiota were attributed to heterotrophy, aerobic heterotrophy, fermentation, and nitrate reduction, independent of plant niches or plant species. Co-occurrences network analyses identified 5 (e.g., Microbacteriaceae, Pseudomonaceae, Lactobacillaceae, and Corynebacteriaceae), 23 (e.g., Chitinophagaceae and Sphingomonadaceae) and 7 (e.g., Rhodospirillaceae) putative keystone taxa present in endosphere, phyllosphere, and rhizosphere, respectively. Our results revealed niche differentiation in Antarctic vascular plants, highlighting some putative microbial indicators and keystone taxa in each niche. However, more studies are required to determine the pivotal role that these microbes play in the successful colonization of ice-free lands by Antarctic plants.

The major priority of research in the present day is to conserve the environment by reducing GHG emissions. A proposed solution by an expert panel from 195 countries meeting at COP 21 was to increase global SOC stocks by 0.4% year−1 to compensate for GHG emissions, the ‘4 per 1000′ agreement. In this context, the application of biocrusts is a promising framework with which to increase SOC and other soil functions in the soil–plant continuum. Despite the importance of biocrusts, their application to agriculture is limited due to: (1) competition with native microbiota, (2) difficulties in applying them on a large scale, (3) a lack of studies based on carbon (C) balance and suitable for model parameterization, and (4) a lack of studies evaluating the contribution of biocrust weathering to increase C sequestration. Considering these four challenges, we propose three perspectives for biocrust application: (1) natural microbiome engineering by a host plant, using biocrusts; (2) quantifying the contribution of biocrusts to C sequestration in soils; and (3) enhanced biocrust weathering to improve C sequestration. Thus, we focus this opinion article on new challenges by using the specialized microbiome of biocrusts to be applied in a new environment to counteract the negative effects of climate change.

“Take-all” disease is the most important biotic factor affecting cereal productivity, causing 30–50% of crop losses. The causal agent is the ascomycete soil-borne pathogen Gaeumannomyces graminis var. tritici (Ggt). Current control measures are ineffective, because Ggt can remain saprophytic in soils for long periods. Therefore, the study of the microbiome residing in suppressive soils (SS) is a promising niche of Ggt biocontrol. Here, we evaluated the efficiency of Serratia sp., Bacillus sp., and Acinetobacter sp. isolated from SS against the incidence of Ggt on wheat. Our results demonstrated that plants inoculated with the bacterial consortium in both greenhouse and field conditions were highly efficient in Ggt biocontrol, more so than individual strains. The disease reduction was evidenced by higher biomass production, fewer copies of the Ggt genome with a concomitant curtailment of blackening of roots, a decrease of lipid peroxidation, and an increase of superoxide dismutase activity. The ability of the microbial consortium over that of single strains could be attributable to interspecies communication as a strategy to biocontrol; i.e., higher chitinase activity. In conclusion, bacterial consortia from SS are an important niche of Ggt biocontrol, serving as a model for other soil-borne pathogens.

Much progress has been achieved in the preparation and application of engineered nanoparticles (NPs) in the field of medicine, mainly for antibacterial and antiviral applications. In the war against bacteria and viruses, besides traditional antibiotics and antiviral drugs, metal-based nanoparticles, such as silver (AgNPs), copper (CuNPs), copper oxides (CuO-NPs), iron oxide (FeO-NPs), zinc oxide (ZnO-NPs), and titanium oxide (TiO2-NPs) have been used as potent antimicrobial agents. These nanoparticles can be synthesized by traditional methods, such as chemical and physical routes, or more recently by biogenic processes. A great variety of macro and microorganisms can be successfully used as reducing agents of metal salt precursors in the biogenic synthesis of metal-based NPs for antimicrobial activity. Depending on the nature of the biological agent, NPs with different sizes, aggregation states, morphology, surface coatings and charges can be obtained, leading to different antimicrobial effects. Considering the drug resistance to traditional therapies, the development of versatile nanomaterials with potent antimicrobial effects is under intensive investigation. In this sense, this review presents and discusses the recent progress in the preparation and application of metal-based nanoparticles biogenically synthesized for antibacterial and antivirus applications. The strength and limitations are critically discussed.

The environment in which nurses and rehabilitation therapists practice is rapidly evolving, resulting in changes in the skill sets and competencies required of new graduates. Evidence-based practice models, for example, require that entry-level nurses, physical therapists, and occupational therapists have the ability to identify, locate, and critically appraise research findings. This paper will describe curriculum-integrated, for-credit information literacy programs developed by the authors in collaboration with faculty members from the Schools of Nursing and Rehabilitation Therapy at Queen's University in Kingston, Ontario. The short-term goal of these programs is to teach undergraduate and graduate students advanced search strategy skills and critical appraisal techniques that will enable them to explore the implications of their literature findings. The long-term goal is to graduate practitioners who not only will have the skills to practice evidence-based health care but also will participate in scholarly activities and thus contribute to the evidence base in their disciplines.

As a result of the wide use of tubular heat exchangers in industry and considering the main heat transfer and friction limitations they possess compared to new technologies, heat transfer promoters of different shapes have appeared in recent years to improve their thermohydraulic performance. To date, there are many different promoter geometries each with its heat transfer and friction performance. This situation makes the selection of the right promoter for retrofit applications a complex task. To overcome this situation, this paper provides a performance mapping plot for the identification of the best promoter geometries out of the many available. This work demonstrates that it is possible to identify the promoters that best perform out of the many geometries available in applications at low and high-pressure drops. To this end, an arbitrarily selected group of different turbulence promoters are compared in terms of measurable parameters such as heat load and pressure drop. Besides, the results are confirmed using thermal and pressure drop irreversibility analysis. Different selection criteria can be applied based on the allowable pressure drop. In the case of retrofit, the best performance is identified by increased heat load for the same installed area with the lowest increment on pressure drop compared to the base case.