Brevibacterium EB3 inoculation enhances rhizobacterial community interactions leading to improved growth of Salicornia europaea

Plant growth-promoting bacteria (PGPB) can revolutionize sustainable agriculture by improving crop yields and resilience in the face of climate change and soil degradation. However, one of the challenges of using PGPB is identifying strains that can colonize and establish beneficial relationships with plant hosts and microbiomes. This study examined the effects of single and co-inoculations with three PGPB strains (Brevibacterium casei EB3, Pseudomonas oryzihabitans RL18, and Bacillus aryabhattai SP20) on the rhizosphere microbiome of the halophyte crop Salicornia europaea. 16S rRNA gene amplicon sequencing was used to analyze the rhizosphere bacterial communities' diversity, structure, and composition. PGPB inoculations significantly changed the diversity and structure of the bacterial communities in the rhizosphere, accounting for 74 % of the total variability. The strain B. casei EB3 was the most effective at colonizing the rhizosphere and establishing interactions with other beneficial community members. Notably, the treatments associated with higher plant yield, consistently featured the presence of B. casei EB3 and higher connectivity between this strain and taxa known to promote growth and alleviate salt stress in plants such as Marinobacterium, Pseudomonas and Vibrio. These findings are consistent with bacterial inoculants' direct and indirect effect in boosting bacteria-plant cooperation within the rhizosphere, ultimately leading to a shift towards an optimized rhizosphere and beneficial traits for plants

Raman spectroscopy in Group IV nanowires and nanowire axial heterostructures

The control of the SiGe NW composition is fundamental for the fabrication of high quality heterostructures. Raman spectroscopy has been used to analyse the composition of SiGe alloys. We present a study of the Raman spectrum of SiGe nanowires and SiGe/Si heterostructures. The inhomogeneity of the Ge composition deduced from the Raman spectrum is explained by the existence of a Ge-rich outer shell and by the interaction of the NW with the electromagnetic field associated with the laser beam

Disability and its influence in nutritional assessment tools in elderly people living in nursing homes

Introduction: Poor nutritional status is associated with increased morbidity and mortality, especially in older people. Objective: The aim of this study was to assess nutritional status in elderly nursing home residents with different nutritional test, and to determine which parameters used for nutritional assessment can be carried out in this population, which usually have a high prevalence of functionally dependent residents. Methods: A cross-sectional study was performed in 383 elderly. The nutritional assessment tools used were the Mini Nutritional Assessment (MNA), the new ESPEN consensus definition of malnutrition, and the tool for Controlling Nutritional Status (CONUT). Moreover, the ability to perform basic activities of daily living was assessed with the Barthel index (BI). Results: According to BI, 78.9% had a total dependence and only 20.9% could be weighed and heighed. The prevalence of malnutrition with MNA, ESPEN and CONUT was 21.3%, 17.6% and 20.7%, respectively. The agreement between MNA vs ESPEN criteria was moderate (?= 0.483), but with CONUT was low. Conclusions: Nursing homes had a high percentage of totally dependent residents. This high degree of functional dependence made difficult to obtain some anthropometric parameters such as weight and height, which are essential to carry out most nutritional tests. MNA, CONUT and the new ESPEN criteria of malnutrition showed a high prevalence of malnutrition and risk of malnutrition in subjects in which they could be performed. Introducción: un estado nutricional deficiente está asociado con un incremento de la morbilidad y la mortalidad, especialmente en personas ancianas. Objetivo: el objetivo de este estudio fue evaluar el estado nutricional en ancianos institucionalizados en residencias geriátricas mediante diferentes test nutricionales, y determinar qué parámetros utilizados en la valoración nutricional pueden ser realizados en esta población. Métodos: se llevó a cabo un estudio transversal en 383 ancianos. Las herramientas de valoración nutricional empleadas fueron el Mini Nutritional Assessment (MNA), el nuevo consenso de definición de malnutrición, y el CONUT. Además, la capacidad de realizar las actividades básicas de la vida diaria fue evaluada con el índice de Barthel. Resultados: según el índice de Barthel, hasta un 78, 9% de los residentes tenía una dependencia total, y en solo el 20, 9% se pudo determinar el peso y la talla. La prevalencia de malnutrición con MNA, el consenso de ESPEN y CONUT fueron 21, 3%, 17, 2% y 20, 7%, respectivamente. La concordancia (kappa) entre el MNA y el ESPEN fue moderada (? = 0, 483), pero con CONUT fue baja. Conclusiones: en las residencias geriátricas públicas existe un elevado porcentaje de ancianos totalmente dependientes. Este alto grado de dependencia funcional dificulta la obtención de algunos parámetros antropométricos como el peso y la talla, que son esenciales para llevar a cabo la mayoría de los test de valoración nutricional. El MNA, el CONUT y los nuevos criterios de desnutrición de la ESPEN mostraron una elevada prevalencia de desnutrición y de riesgo de desnutrición en esta población de ancianos institucionalizados, en aquellos en los que fue posible realizarlos

Genetic diversity in nitrogen fertilizer responses and N gas emission in modern wheat

Crops assimilate nitrogen (N) as ammonium via the glutamine synthetase/glutamate synthase (GS/GOGAT) pathway which is of central importance for N uptake and potentially represents a bottle neck for N fertilizer-use efficiency. The aim of this study was to assess whether genetic diversity for N-assimilation capacity exists in wheat and could be exploited for breeding. Wheat plants rapidly, within 6h, responded to N application with an increase in GS activity. This was not accompanied by an increase in GS gene transcript abundance and a comparison of GS1 and GS2 protein models revealed a high degree of sequence conservation. N responsiveness amongst ten wheat varieties was assessed by measuring GS enzyme activity, leaf tissue ammonium, and by a leaf-disc assay as a proxy for apoplastic ammonia. Based on these data, a high-GS group showing an overall positive response to N could be distinguished from an inefficient, low-GS group. Subsequent gas emission measurements confirmed plant ammonia emission in response to N application and also revealed emission of N2O when N was provided as nitrate, which is in agreement with our current understanding that N2O is a by-product of nitrate reduction. Taken together, the data suggest that there is scope for improving N assimilation capacity in wheat and that further investigations into the regulation and role of GS-GOGAT in NH3 emission is justified. Likewise, emission of the climate gas N2O needs to be reduced, and future research should focus on assessing the nitrate reductase pathway in wheat and explore fertilizer management options

University-enterprises: a win-win relationship, from business to research

Teaching at University is always a difficult task because it implies too much theoretical lessons while students ask for practical knowledge and Enterprises claim for good junior professionals. Finding an equilibrium among all the interests is challenging but at the same time, it is the key of success. This work shows the experience of teaching in collaboration with companies to achieve a more practical and attractive approach to day-to-day Engineering work while meeting teaching objectives. It is a win-win relationship since it motivates students because they see the direct relationship between their studies and the future job; it also helps teachers to know the knowledge required by engineering companies and, besides, enterprises will have future engineers better trained, already familiar with process and tools. Furthermore, it also increases the collaborations between University and enterprises, which is key to innovate and develop new business modelsPostprint (published version

Inorganic Chemical Fertilizer Application to Wheat Reduces the Abundance of Putative Plant Growth-Promoting Rhizobacteria

The profound negative effect of inorganic chemical fertilizer application on rhizobacterial diversity has been well documented using 16S rRNA gene amplicon sequencing and predictive metagenomics. We aimed to measure the function and relative abundance of readily culturable putative plant growth-promoting rhizobacterial (PGPR) isolates from wheat root soil samples under contrasting inorganic fertilization regimes. We hypothesized that putative PGPR abundance will be reduced in fertilized relative to unfertilized samples. Triticum aestivum cv. Cadenza seeds were sown in a nutrient depleted agricultural soil in pots treated with and without Osmocote⃝R fertilizer containing nitrogen-phosphorous-potassium (NPK). Rhizosphere and rhizoplane samples were collected at flowering stage (10 weeks) and analyzed by culture-independent (CI) amplicon sequence variant (ASV) analysis of rhizobacterial DNA as well as culture- dependent (CD) techniques. Rhizosphere and rhizoplane derived microbiota culture collections were tested for plant growth-promoting traits using functional bioassays. In general, fertilizer addition decreased the proportion of nutrient-solubilizing bacteria (nitrate, phosphate, potassium, iron, and zinc) isolated from rhizocompartments in wheat whereas salt tolerant bacteria were not affected. A “PGPR” database was created from isolate 16S rRNA gene sequences against which total amplified 16S rRNA soil DNA was searched, identifying 1.52% of total community ASVs as culturable PGPR isolates. Bioassays identified a higher proportion of PGPR in non-fertilized samples [rhizosphere (49%) and rhizoplane (91%)] compared to fertilized samples [rhizosphere (21%) and rhizoplane (19%)] which constituted approximately 1.95 and 1.25% in non-fertilized and fertilized total community DNA, respectively. The analyses of 16S rRNA genes and deduced functional profiles provide an in-depth understanding of the responses of bacterial communities to fertilizer; our study suggests that rhizobacteria that potentially benefit plants by mobilizing insoluble nutrients in soil are reduced by chemical fertilizer addition. This knowledge will benefit the development of more targeted biofertilization strategies

Electromagnetic fields disrupt the pollination service by honeybees

We assessed the effect that electromagnetic field (EMF) exerts on honeybees’ pollination efficiency using field and laboratory experiments. First, we measured levels of gene and protein expression in metabolic pathways involved in stress and behavioral responses elicited by EMF. Second, we assessed the effect of EMF on honeybee behavior and seed production by the honeybee-pollinated California poppy and, lastly, by measuring the consequences of pollination failure on plants’ community richness and abundance. EMF exposure exerted strong physiological stress on honeybees as shown by the enhanced expression of heat-shock proteins and genes involved in antioxidant activity and affected the expression levels of behavior-related genes. Moreover, California poppy individuals growing near EMF received fewer honeybee visits and produced fewer seeds than plants growing far from EMF. Last, we found a hump-shaped relationship between EMF and plant species richness and plant abundance. Our study provides conclusive evidence of detrimental impacts of EMF on honeybee’s pollination behavior, leading to negative effects on plant community.Fil: Molina Montenegro, Marco A.. Universidad de Talca; ChileFil: Acuña Rodríguez, Ian S.. Universidad de Talca; ChileFil: Ballesteros, Gabriel I.. Universidad de Talca; ChileFil: Baldelomar, Mariela. Universidad de Talca; ChileFil: Torres Díaz, Cristian. Universidad del Bio Bio; ChileFil: Broitman, Bernardo R.. Universidad Adolfo Ibañez; ChileFil: Vazquez, Diego P.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentin

Central star formation and metallicity in CALIFA interacting galaxies

We use optical integral-field spectroscopic (IFS) data from 103 nearby galaxies at different stages of the merging event, from close pairs to merger remnants provided by the CALIFA survey, to study the impact of the interaction in the specific star formation and oxygen abundance on different galactic scales. To disentangle the effect of the interaction and merger from internal processes, we compared our results with a control sample of 80 non-interacting galaxies. We confirm the moderate enhancement (2-3 times) of specific star formation for interacting galaxies in central regions as reported by previous studies; however, the specific star formation is comparable when observed in extended regions. We find that control and interacting star-forming galaxies have similar oxygen abundances in their central regions, when normalized to their stellar masses. Oxygen abundances of these interacting galaxies seem to decrease compared to the control objects at the large aperture sizes measured in effective radius. Although the enhancement in central star formation and lower metallicities for interacting galaxies have been attributed to tidally induced inflows, our results suggest that other processes such as stellar feedback can contribute to the metal enrichment in interacting galaxies.Comment: 9 pages, 9 figures. Accepted for publication in Astronomy & Astrophysic

Spitzer Observations of IC 2118

IC 2118, also known as the Witch Head Nebula, is a wispy, roughly cometary, ~5 degree long reflection nebula, and is thought to be a site of triggered star formation. In order to search for new young stellar objects (YSOs), we have observed this region in 7 mid- and far-infrared bands using the Spitzer Space Telescope and in 4 bands in the optical using the U. S. Naval Observatory 40-inch telescope. We find infrared excesses in 4 of the 6 previously-known T Tauri stars in our combined infrared maps, and we find 6 entirely new candidate YSOs, one of which may be an edge-on disk. Most of the YSOs seen in the infrared are Class II objects, and they are all in the "head" of the nebula, within the most massive molecular cloud of the region.Comment: Accepted to Ap

Secondary Infall in the Seyfert\u27s Sextet: A Plausible Way out of the Short Crossing Time Paradox

We used integral field spectroscopy from CALIFA DR3 and multiwavelength publicly available data to investigate the star formation histories of galaxies in the Seyfert\u27s Sextet (SS; HCG 79). The galaxies H79a, H79b, H79c, and H79f have low star formation rates despite showing strong signs of interaction. By exploring their individual specific star formation histories, we identified three earlier episodes of strong star formation common to these four galaxies. We use the last two episodes as markers of the epochs when the galaxies were crossing. We suggest that after the first turnaround, initially gas-rich galaxies crossed for the first time, consuming most of their gas. Hence, after the second turnaround most mergers from second crossings would be mixed or dry. The exception would be gas-rich galaxies intruding for the first time. Therefore, we suggest that SS galaxies have survived one crossing during a Hubble time. Strong Balmer absorption lines and the presence of counter-rotating disks provide independent bounds to the second and first crossing, respectively. This scenario provides a plausible way out of the short crossing time paradox