893 research outputs found

    Gentle remediation options for soil with mixed chromium (VI) and lindane pollution: biostimulation, bioaugmentation, phytoremediation and vermiremediation

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    Gentle Remediation Options (GROs), such as biostimulation, bioaugmentation, phytoremediation and vermiremediation, are cost-effective and environmentally-friendly solutions for soils simultaneously polluted with organic and inorganic compounds. This study assessed the individual and combined effectiveness of GROs in recovering the health of a soil artificially polluted with hexavalent chromium [Cr(VI)] and lindane. A greenhouse experiment was performed using organically-amended vs. non-amended mixed polluted soils. All soils received the following treatments: (i) no treatment; (ii) bioaugmentation with an actinobacteria consortium; (iii) vermiremediation with Eisenia fetida; (iv) phytoremediation with Brassica napus; (v) bioaugmentation + vermiremediation; (vi) bioaugmentation + phytoremediation; and (vii) bioaugmentation + vermiremediation + phytoremediation. Soil health recovery was determined based on Cr(VI) and lindane concentrations, microbial properties and toxicity bioassays with plants and worms. Cr(VI) pollution caused high toxicity, but some GROs were able to partly recover soil health: (i) the organic amendment decreased Cr(VI) concentrations, alleviating toxicity; (ii) the actinobacteria consortium was effective at removing both Cr(VI) and lindane; (iii) B. napus and E. fetida had a positive effect on the removal of pollutants and improved microbial properties. The combination of the organic amendment, B. napus, E. fetida and the actinobacteria consortium was the most effective strategy.Fil: Lacalle, Rafael G.. Universidad del País Vasco; EspañaFil: Aparicio, Juan Daniel. Universidad Nacional de Tucumán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Artetxe, Unai. Universidad del País Vasco; EspañaFil: Urionabarrenetxea, Erik. Universidad del País Vasco; EspañaFil: Polti, Marta Alejandra. Universidad Nacional de Tucumán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Soto, Manuel. Universidad del País Vasco; EspañaFil: Garbisu, Carlos. Centro de Investigación. Neiker - Tecnalia; EspañaFil: Becerril, José M.. Universidad del País Vasco; Españ

    Niveles de fósforo disponible aparente en pollas Leghorn blanca durante las etapas de iniciación, crecimiento, desarrollo e inicio de postura

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    Phosphorus (P) is important for the growth and metabolism of pullets and young laying hens, although the requeriments of this mineral could be overvalued. An experiment was conducted with 750 Hy-line W-36 pullets to evaluate the effects of apparent available phosphorus (aaP) levels during starter (1 d to 6 wk), growing (7 to 12 wk), development (13 to 18 wk), and initial laying period. The analyzed variables were: body weight (BW), feed intake (FI), percentage of P in excreta (PPE) and tibia bone (TBP), tibia breaking strength (TBS), egg mass (EM), and specific gravity (SG). The evaluated aaP levels had no effect (P>0.05) on FI, FP, TBP, RB, or EM in the stages under study. There was a difference (P0.05) in the starter period, the optimum biological levels for growing and finishing stages were 0.28 and 0.26 % of aaP, respectively. It was concluded that the requirements of apparent available phosphorus could be lower than the value suggested by NRC (1994) for the growth stages and the variables measured, without affecting the body condition and bone mineralization of pullets.El fósforo es importante en el metabolismo y desarrollo de las pollitas de reemplazo, aunque las necesidades de este mineral pueden estar sobrevaloradas. Se realizó un experimento con 750 pollas de la lí­nea Hy-line W-36, para evaluar los efectos de niveles de fósforo disponible aparente (Pda) durante las etapas de iniciación (1 dí­a a 6 semanas), crecimiento (7 a 12 semanas), desarrollo (13 a 18 semanas) y de inicio a pico de postura. Las caracterí­sticas estudiadas fueron: peso vivo (PV), consumo de alimento (CA), porcentaje de fósforo total en excretas y tibias (PTE y PT), resistencia a ruptura de tibias (RR), masa de huevo (MH) y gravedad especí­fica (GE). El nivel de Pda no afectó (P>0.05) el CA, PTE, PT, RR y MH en las etapas estudiadas. Hubo diferencias (P0.05), mientras que los niveles óptimos biológicos para PV en crecimiento fueron con 0.28 % y desarrollo 0.26 %. Se concluye que las necesidades de fósforo disponible aparente pueden ser menores a lo sugerido por el NRC (1994), durante las etapas y caracterí­sticas medidas, sin afectar la condición corporal y mineralización ósea de las aves

    Foliar heavy metals and stable isotope (δ13C, δ15N) profiles as reliable urban pollution biomonitoring tools

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    Anthropogenic heavy metal pollution is an important health issue in urban areas, and therefore rapid and inexpensive monitoring in time and space is desirable. This study aimed (i) to assess the suitability of Tilia cordata leaves as a valuable heavy metal bioindicator, including seasonal changes in concentrations and (ii) to evaluate the use of leaf carbon and nitrogen isotope composition (δ13C and δ15N) as novel indicators of urban heavy metal pollution. Leaves were collected from three different pollution intensity locations (Bilbao, Vitoria, and Muskiz) in the Basque Country (northern Spain). Analysis of leaf heavy metals related to traffic emissions and δ13C and δ15N determinations were carried out during July-October 2018. Leaf samples from Bilbao, the most populated and traffic-intense location, showed the highest concentration of heavy metals (mainly from polluted air). Additionally, the two urban areas, Bilbao and Vitoria, showed stronger correlation between these heavy metals, indicating a traffic-related source of emissions. The source of contamination (soil or air) in relation to elements and optimal sampling time is discussed herein. On the other hand, Pearson correlation analysis revealed significant trends between leaf δ13C and δ15N and the studied heavy metals, especially Pb, Cr and Cd, supporting the hypothesis of δ13C and δ15N as tools to distinguish locations according to their heavy metal pollution levels. To our knowledge, this is the first time that δ13C and δ15N have been used as monitoring tools in heavy metal pollution and consequently more research is still needed to calibrate this tool through extensive vegetation screening.This research was supported by the Spanish Government [AGL 2015-64481-C2-1-R] and the Basque Government [UPV/EHU-GV IT-1018-16]. RE received a Juan de la Cierva incorporation contract IJCI-2014-21452

    How Valuable Are Organic Amendments as Tools for the Phytomanagement of Degraded Soils? The Knowns, Known Unknowns, and Unknowns

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    Nowadays, soil functionality and productivity are severely impaired due, in great part, to the fact that most of the land is being intensively used for food production and urbanization purposes, with a consequent rise in the generation of wastes and consumption/degradation of fertile soils. These issues can be jointly addressed by an integrated and sustainable management of the soil resource carried out in the framework of two recent paradigms: circular economy and phytomanagement. Within the fields of resource conservation and regenerative (urban) land management, at least the three following fundamental aspects can be contemplated: (i) the valorization and safe recovery of organic wastes (e.g., composts, green and animal manures, and biosolids) as soil amendments (from residue to resource); (ii) the re-development and revegetation of degraded soils characterized by low organic matter content, deficient physical structure and depressed biological status (from bare to vegetated soil); and, finally, (iii) the promotion of soil health in order to support soil ecological processes, functions and concomitant ecosystem services (integration of ecocentric and anthropocentric perspectives). Here, we discuss the benefits (knowns), potential risks (known unknowns) and future/affordable uncertainties (unknowns) resulting from the application of organic amendments (OAs) to soil. Traditionally, most studies have used physical-chemical parameters to assess soil health/quality, whereas less attention has been paid to soil biological criteria. Thus, we highlight the relevance of soil biological properties as key drivers of ecological restoration and suitable indicators of soil health. Notwithstanding, special attention should be paid to “amendments-plants-microorganisms” interactions in different soils and field conditions. Finally, the risk of introduction of emerging contaminants, including for instance microplastics and antibiotic resistance genes (ARGs), through the application of OAs to soil, is currently a matter of much concern that must urgently be addressed if we are to continue with such practice

    Suckling, male effect and kisspeptin in the reproductive management of ewes in postpartum anestrus

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    Objective: To describe the management strategies of controlled suckling and the male effect to reduce postpartum anestrus, and to show the participation of kisspeptin to regulate the effect of both factors. Design/Methodology/Approach: A review of scientific publications was conducted, in order to show the importance of suckling and the male effect as strategies to reduce postpartum anestrus in the ewe, as well as the relation of kisspeptin with both factors. Results: Seasonal anestrus can be avoided with the use of breeds adapted to the local environment, such as Pelibuey. Postpartum anestrus occurs mainly as a result of suckling, since the latter inhibits the pulsating secretion of the gonadotropin-releasing hormone (GnRH) and the luteinizing hormone (LH). The exact path of this inhibition is unknown, although it seems that endogenous opioid peptides and kisspeptin are intermediaries. Controlled suckling and the male effect are management strategies that improve the reproductive behavior of postpartum ewes. Kisspeptin regulates the influence of the male effect through the secretion of GnRH/LH. Study Limitations/Implications: To understand the impacts of suckling and the male effect on the duration of postpartum anestrus, as well as the participation of kisspeptin in the regulation of both effects, will allow designing management strategies to improve the reproductive efficiency of the ewes. Findings/Conclusions: Controlled suckling and the male effect reduce postpartum anestrus and improve the reproductive behavior of the ewes; advancing knowledge of the kisspeptin effect could improve the effectiveness of both techniques

    Adipose tissue knockdown of lysozyme reduces local inflammation and improves adipogenesis in high-fat diet-fed mice

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    Chronic systemic low-level inflammation in metabolic disease is known to affect adipose tissue biology. Lysozyme (LYZ) is a major innate immune protein but its role in adipose tissue has not been investigated. Here, we aimed to investigate LYZ in human and rodents fat depots, and its possible role in obesity-associated adipose tissue dysfunction. LYZ mRNA and protein were identified to be highly expressed in adipose tissue from subjects with obesity and linked to systemic chronic-low grade inflammation, adipose tissue inflammation and metabolic disturbances, including hyperglycemia, dyslipidemia and decreased markers of adipose tissue adipogenesis. These findings were confirmed in experimental models after a high-fat diet in mice and rats and also in ob/ob mice. Importantly, specific inguinal and perigonadal white adipose tissue lysozyme (Lyz2) gene knockdown in high-fat diet-fed mice resulted in improved adipose tissue inflammation in parallel to reduced lysozyme activity. Of note, Lyz2 gene knockdown restored adipogenesis and reduced weight gain in this model. In conclusion, altogether these observations point to lysozyme as a new actor in obesity-associated adipose tissue dysfunction. The therapeutic targeting of lysozyme production might contribute to improve adipose tissue metabolic homeostasis

    GLP-1 limits adipocyte inflammation and its low circulating pre-operative concentrations predict worse type 2 diabetes remission after bariatric surgery in obese patients

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    Objective: Glucagon-like peptide (GLP)-1 has been proposed as a key candidate in glucose improvements after bariatric surgery. Our aim was to explore the role of GLP-1 in surgically-induced type 2 diabetes (T2D) improvement and its capacity to regulate human adipocyte inflammation. Methods: Basal circulating concentrations of GLP-1 as well as during an oral glucose tolerance test (OGTT) were measured in lean and obese volunteers with and without T2D (n = 93). In addition, GLP-1 levels were determined before and after weight loss achieved by Roux-en-Y gastric bypass (RYGB) (n = 77). The impact of GLP-1 on inflammation signalling pathways was also evaluated. Results: We show that the reduced (p < 0.05) circulating levels of GLP-1 in obese T2D patients increased (p < 0.05) after RYGB. The area under the curve was significantly lower in obese patients with (p < 0.01) and without (p < 0.05) T2D compared to lean volunteers while obese patients with T2D exhibited decreased GLP-1 levels at baseline (p < 0.05) and 120 min (p < 0.01) after the OGTT. Importantly, higher (p < 0.05) pre-operative GLP-1 concentrations were found in patients with T2D remission after RYGB. We also revealed that exendin-4, a GLP-1 agonist, downregulated the expression of inflammation-related genes (IL1B, IL6, IL8, TNF) and, conversely, upregulated the mRNA levels of ADIPOQ in human visceral adipocytes. Furthermore, exendin-4 blocked (p < 0.05) LPS-induced inflammation in human adipocytes via downregulating the expression and secretion of key inflammatory markers. Conclusions: Our data indicate that GLP-1 may contribute to glycemic control and exert a role in T2D remission after RYGB. GLP-1 is also involved in limiting inflammation in human visceral adipocytes

    Ciudad-territorio sustentable. Procesos, actores y estructuras

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    En los últimos años, los estudios urbanos especializados insisten en que los procesos de urbanización por los que atraviesan los distintos países desarrollados, parecen dejar atrás las explicaciones de la urbanización industrial, han surgido otras construcciones y perspectivas unas más acabadas que otras (Indovina, 1998, la “ciudad difusa”; Dematteis 1998, ciudad sin centros; Nel-lo, 1998 ciudad sin confines, Soja, 2008, la exópolis). En suma se dice que se avanza hacia la urbanización generalizada, ello acaba con la larga trayectoria del funcionamiento y naturaleza de la ciudad moderna, el cambio urbano estructural actual, es nuevamente, consecuencia de la descentralización, difusión, redistribución del desarrollo, del crecimiento y las innovaciones ahora sobre una estructura en el territorio. Ha sido una mutación no sólo empírica sino que ha dado lugar a la confrontación teórica. El sistema urbano jerárquico ha reducido su valor interpretativo porque se han modificado los supuestos en los que se basaban las relaciones de dominio y dependencia de los centros principales, porque se han abaratado los costos de transporte y el efecto de la distancia ya no es una limitante absoluta, ahora los procesos productivos flexibles y descentralizados propician las relaciones técnicas horizontales con lo cual se consiguen economías de escala externas e internas a las empresas en un territorio ampliado y no sólo exclusivamente en la aglomeración económica (Precedo, 2003; Veltz, 1999; Boix, 2002; Camagni, 2005; De Santiago, 2008 y; Garmendia, 2010).El objetivo es examinar dentro de la descentralización del proceso urbano a la ciudad-territorio en América Latina, en particular en México. En contextos urbanos desarrollados se afirma la convergencia urbana con la apertura de las unidades funcionales de los sistemas urbanos donde operan redes e interrelaciones de desarrollo cualitativo en el territorio. América Latina registra evidencias empíricas poco claras, existe alta concentración de aquella economía que contribuye al crecimiento nacional, mientras la población se descentraliza rápidamente. México, es un caso de primacía urbana histórica aunque da paso a la formación de regiones urbanas, mismas que reproducen relaciones polarizadas y escasamente descentralizadas. De manera que, en tanto domine la concentración espacial económica, la ciudadterritorio se podrá presentar en el continente sólo con algunos rasgos en regiones urbanas con mayor desarrollo y crecimiento. Palabras claves: descentralización urbana, sistema urbano, ciudad-territorio
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