The role of biochar and green compost amendments in the adsorption, leaching, and degradation of sulfamethoxazole in basic soil.

The fate of the antibiotic sulfamethoxazole in amended soils remains unclear, moreover in basic soils. This work aimed to assess the adsorption, leaching, and biodegradation of sulfamethoxazole in unamended and biochar from holm oak pruning (BC)- and green compost from urban pruning (CG)-amended basic soil. Adsorption properties of the organic amendments and soil were determined by adsorption isotherms of sulfamethoxazole. The leachability of this antibiotic from unamended (Soil) and BC- (Soil + BC) and GC- (Soil + GC) amended soil was determined by leaching columns using water as solvent up to 250 mL. Finally, Soil, Soil + BC, and Soil + GC were spiked with sulfamethoxazole and incubated for 42 days. The degradation rate and microbial activity were periodically monitored. Adsorption isotherms showed poor adsorption of sulfamethoxazole in unamended basic soil. BC and CG showed good adsorption capacity. Soil + BC and Soil + GC increased the sulfamethoxazole adsorption capacity of the soil. The low sulfamethoxazole adsorption of Soil produced quick and intense sulfamethoxazole leaching. Soil + BC reduced the sulfamethoxazole leaching, unlike to Soil + GC which enhanced it concerning Soil. The pH of adsorption isotherms and leachates indicate that the anion of sulfamethoxazole was the major specie in unamended and amended soil. CG enhanced the microbial activity of the soil and promoted the degradability of sulfamethoxazole. In contrast, the high adsorption and low biostimulation effect of BC in soil reduced the degradation of sulfamethoxazole. The half-life of sulfamethoxazole was 2.6, 6.9, and 11.9 days for Soil + GC, Soil, and Soil + BC, respectively. This work shows the benefits and risks of two organic amendments, BC and GC, for the environmental fate of sulfamethoxazole. The different nature of the organic carbon of the amendments was responsible for the different effects on the soil.

Adaptative Strategies in Gymnocalycium Species (Cactaceae) and the Presence of Ectomycorrhizae Associated with Survival in Arid Environments.

The Cactaceae family makes use of different strategies, both physiological and biochemical, for anatomical adjustments that allow them to grow and reproduce in arid environments. Morphological studies of Gymnocalycium have been scarce, and the anatomy and phytochemistry are still largely unknown. The aim of the present work was to analyze the structural, physiological, and biochemical features of Gymnocalycium marianae and G. oenanthemum, two endemic species of arid regions in Argentina. The anatomic structure, biomass, and photosynthetic pigments, as well as phenolic compound contents, were analyzed in the stem, spine, and root of both species. G. marianae showed stems with deeper substomatal chambers and a more developed photosynthetic tissue than G. oenanthemum. The spines of G. oenanthemum showed higher biomass, thicker epidermal and subepidermal cell walls, and a higher content of phenolic compounds than those of G. marianae. Ectomycorrhizae were observed for the first time in roots in both species. Roots of G. marianae showed high colonization, biomass, and content of phenolic compounds. Both species showed abundant mucilaginous fibers in the stem and root. Finally, these results show the strategies associated with the survival in xeric environments of two cacti species at risk of extinction. They could be useful for the development of ex situ conservation programs.

Dietary protein reduction with stepwise addition of crystalline amino acids and the effect of considering a minimum glycine-serine content in broiler diets.

Reducing the dependency on soybean meal (SBM) is necessary to improve the sustainability of the poultry industry. Moreover, the recommendations for minimum contents of dietary Gly+Ser require further research. Two parallel studies were executed to determine the effects of replacing SBM with crystalline amino acids (CAA) to meet the amino acid requirements and to determine whether a minimum content of Gly+Ser is necessary for broiler diets. In study 1, 1,860 one-day-old male chicks were fed a common starter phase diet (22.8% CP). During the grower-1, grower-2, and finisher phases, the control CP content was reduced (up to 2.1%) with the stepwise addition of CAA (treatments 1-5). Within each feeding phase, AME, standardized ileal digestible Lys, and the minimum Met, Thr, Val, Gly+Ser, Ile, Arg, and Trp to Lys ratios were similar. In study 2, 1,488 male chickens were used in a 2 × 2 factorial design with the Gly+Ser content and feed ingredients used as main factors. Performance was monitored during 41 d in both studies. Reduction in CP content linearly increased (P < 0.05) BW, ADG, and ADFI in the grower-1, grower-2, and finisher phases. When the overall FCR was adjusted considering the BW differences (FCRadj); FCRadj linearly decreased with the weighted average CP (WACP) content (P < 0.001). In the lowest CP treatment, estimated dietary N utilization efficiency was improved by 10%, and the overall N excretion was reduced by 16% compared with the control (P < 0.001). The overall SBM and soybean oil intakes were linearly reduced relative to WACP (-12.0 and -20.2% in control vs. treatment 5, respectively; P < 0.001). Formulating with a minimum Gly+Ser content in the starter phase improved the FCR (P < 0.05) only in the corn-SBM-based diet. In grower-1, increasing Gly+Ser content improved the FCR independent of the feed ingredients used (P < 0.05). Crystalline amino acids can be used to partially replace intact protein reducing the dependency on SBM. Young birds may not synthesize enough Gly endogenously and a minimum content should be provided in the early phases.

The effect of gradually decreasing the dietary energy content, at constant or increased lysine:energy ratio on broiler performance, carcass yield, and body composition.

Formulating diets with high AME, especially in the grower and finisher phases, hinders the inclusion of alternative ingredients that are usually cheaper and have lower AME. Moreover, as the chicken grows the feed intake capacity is greater and may be able to maintain BW over a wide range of AME. The objective of this study was to evaluate the performance of chickens fed diets with progressive AME reductions, at constant or increased standardized ileal digestible (SID) lysine:AME ratio (Lys:AME). Treatment 1 (control) was formulated following the SID lysine and AME recommendations for a 4-phase feeding program. Treatment 5 was formulated with -4, -8, and -12% AME in the grower-1, grower-2, and finisher phases, respectively, and with the same Lys:AME compared with the control. Treatment 9 had the same AME as treatment 5 but higher SID lysine, increasing the Lys:AME by 1.5, 3.5, and 5.0% compared with treatment 5. In the grower-1, grower-2, and finisher phases, the final 9 dietary treatments were prepared by mixing the control diet with either treatment 5 or 9 at different proportions (75:25, 50:50, or 25:75). All birds were fed the same starter control diet. Treatments were replicated in 10 pens with 31 male chickens each, and the growth performance of birds was monitored for 42 d. Final BW linearly decreased (P < 0.05) when lowering dietary AME, but it followed a positive quadratic response with higher Lys:AME (P < 0.05). Feed intake increased (P < 0.05) with low AME, independently of the Lys:AME; but the linear regression in the feed conversion ratio (FCR) had a lower slope when the Lys:AME increased. At the end of the study, there were no differences in carcass or breast meat yield (P > 0.10). Progressively reducing AME in the last feeding phases may be a viable nutritional strategy to increase the inclusion of alternative ingredients and potentially reduce feeding costs, despite increments in feed intake and FCR. Adjusting the Lys:AME in low AME diets may help maintain the final BW of birds.

Impact of Pneumococcal Vaccination in the Nasopharyngeal Carriage of Streptococcus pneumoniae in Healthy Children of the Murcia Region in Spain.

BACKGROUND: An epidemiological study of Streptococcus pneumoniae nasopharyngeal carriage in healthy children was carried out five years after the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13). OBJECTIVES: Study the impact of pediatric vaccination with PCV13, and other associated epidemiological factors on the status of nasopharyngeal carriage, the circulating pneumococcal serotypes, and the antibiotic susceptibility to more frequently used antibiotics. METHODS: A multi-center study was carried out in Primary Health Care, which included 1821 healthy children aged 1 to 4 years old. All isolates were sent to the Spanish Pneumococcal Reference Laboratory for serotyping and antimicrobial susceptibility testing. RESULTS: At least one dose of PCV13 had been received by 71.9% of children and carriage pneumococcal prevalence was 19.7%. The proportion of PCV13 serotypes was low (14.4%), with an observed predominance of non-vaccine serotypes, 23B, 11A, 10A, 35B/F, and 23A were the five most frequent. A high rate of resistance to penicillin, erythromycin, and trimethoprim sulfamethoxazole was found. CONCLUSIONS: A low proportion of PCV13 serotypes were detected, confirming the impact of pediatric vaccination for reducing the serotypes vaccine carriage. High resistance rates to clinically important antibiotics were observed.

The effect of reducing dietary calcium in prestarter diets (0-4 D) on growth performance of broiler chickens, tibia characteristics, and calcium and phosphorus concentration in blood.

During the incubation period, the Ca-to-P weight (mg/mg) ratio in the yolk increases from 0.26 on day 0 to 0.92 on day 17.5 and to 2.9 at hatch. Moreover, the absolute Ca content in the yolk increases by 41%, whereas P content decreases by 87%, from day 0 to the day of hatching. Thus, at hatch and during the first days after hatching, there are high reserves of Ca relative to P in the residual egg yolk, risking hypercalcemia and hypophosphatemia. A growth performance study was conducted to explore the effects of reducing dietary Ca content in the prestarter phase (0-4 D) on BW and bone mineral deposition during the first days after hatch and at market weight (day 37). Four prestarter (0-4 D) diets were formulated to have 0.4, 0.6, 0.8, and 1.0% Ca content. After the prestarter phase, all birds were fed with the same commercial diets based on a 3-phase feeding program (starter, grower, and finisher). Growth performance (BW, ADG, ADFI, and feed conversion ratio [FCR]) was monitored throughout the study, and blood and tibia bone samples were collected on specific days. On day 4, BW and ADG decreased with dietary Ca contents higher than 0.6% (P < 0.05), but there were no differences in BW on day 14 onward (P > 0.10). For the overall study (0-37 D), there were no differences in ADG and ADFI, but the FCR decreased with lower Ca contents (P < 0.05). On day 4, there were no differences in blood plasma Ca concentration, but P concentration increased in the group treated with diet containing 0.4% Ca compared with the groups treated with diets containing 0.6 and 0.8% Ca (P < 0.05). Tibia ash content decreased in the group treated with diet containing 0.4% Ca (P < 0.05) compared with all other treatments at the end of the prestarter phase. Tibia ash content and tibia breaking strength, on day 37, were not different among the treatments (P > 0.10). In conclusion, during the prestarter phase, BW increased with dietary Ca contents lower than 0.6%, most likely improving Ca-P balance; bone mineral deposition was reduced in this period. On feeding with a diet containing higher Ca content, bone mineral content was rapidly recovered.

Impact of a tire fire accident on soil pollution and the use of clay minerals as natural geo-indicators.

Following the occurrence of a fire at a tire landfill in the surrounding area of Madrid City (Spain), polycyclic aromatic hydrocarbons (PAHs) and trace elements present in soils were analyzed to assess the impact of the fire. The capacity of the soils' clay mineral fraction to reflect this air pollution incident was studied. Fourteen soil samples were collected at different distances under the smoke plume, and they were subjected to high-performance liquid chromatography-photodiode array detection, inductively coupled plasma mass spectrometry and X-ray diffraction analyses. Clay minerals content showed a strong correlation with the pollutants potentially released in the tire fire, acenaphthene, pyrene, benzo(a)pyrene and benzo(a)fluoranthene. Trace metals Zn and Se were related to the proximity of the tire fire without any relationship with clay minerals content. This work suggests the use of natural clay minerals as potential PAHs geo-indicators in response to air pollution, complementary to current air and biological analyses.

Changes with age (from 0 to 37 D) in tibiae bone mineralization, chemical composition and structural organization in broiler chickens.

Broiler chickens have an extreme physiology (rapid growth rates) that challenges the correct bone mineralization, being an interesting animal model for studying the development of bone pathologies. This work studies in detail how the mineralization, chemistry, and structural organization of tibiae bone in broiler chickens change with age during the first 5 wk (37 D) from hatching until acquiring the final weight for slaughter. During the early growth phase (first 2 wk), the rapid addition of bone tissue does not allow for bone organic matrix to fully mineralize and mature, and seems to be a critical period for bone development at which bone mineralization cannot keep pace with the rapid growth of bones. The low degree of bone mineralization and large porosity of cortical bone at this period might be responsible of leg deformation and/or other skeletal abnormalities commonly observed in these birds. Later, cortical bone porosity gradually decreases and the cortical bone became fully mineralized (65%) at 37 D of age. At the same time, bone mineral acquires the composition of mature bone tissue (decreased amount of carbonate, higher crystallinity, Ca/P = 1.68). However, the mineral part was still poorly organized even at 37 D. The oriented fraction was about 0.45 which means that more than half of apatite crystals within the mineral are randomly oriented. Mineral organization (crystal orientation) had an important contribution to bone-breaking strength. Nevertheless, locally determined (at tibia mid-shaft) bone properties (i.e., cortical thickness, crystal orientation) has only a moderate correlation (R2 = 0.33) with bone breaking strength probably due to large and highly heterogeneous porosity of bone that acts as structural defects. On the other hand, the total amount of mineral (a global property) measured by total ash content was the best predictor for breaking strength (R2 = 0.49). Knowledge acquired in this study could help in designing strategies to improve bone quality and reduce the incidence of skeletal problems in broiler chickens that have important welfare and economic implications.

Containment and attenuating layers: An affordable strategy that preserves soil and water from landfill pollution.

The performance of a widely distributed natural clay to attenuate contaminants released from an old landfill was investigated. The objective is to evaluate its potential use as a barrier for waste containment systems. Core samples of the natural clay were collected below the landfill and their parameters distribution with depth was determined. Partition coefficients, retardation factors and percentage values of pollutants concentrations, revealed a rapid decrease of contaminants with depth. The background values of the pollutants were below the maximum limits for drinking and irrigation water and with no need of reactors, collectors, aeration or recirculation systems. Impermeable waste capping is discouraged in order to decrease leachate toxicity, decomposition time and conservative species, and in order to avoid high-reducing conditions that would mobilize redox-sensitive contaminants. A review on leachate-composition evolution and on natural-attenuation processes was undertaken to understand the interactions leachate-substratum, which is essential to properly estimate the leachate transport and implement the attenuation strategy. This strategy complements the traditional containment one regarding (1) the susceptibility of engineering liners to fail, (2) the inevitable diffusion of contaminants through them, (3) the remaining high number of old landfills before the requirements of liner systems and (4) the low-cost and feasibility for developing countries.

Improvement of attenuation functions of a clayey sandstone for landfill leachate containment by bentonite addition.

Enhanced sand-clay mixtures have been prepared by using a sandstone arkosic material and have been evaluated for consideration as landfill liners. A lab-scale test was carried out under controlled conditions with different amended natural sandstones whereby leachate was passed through the compacted mixtures. The compacted samples consisted of siliceous sand (quartz-feldspar sand separated from the arkose sandstone) and clay (purified clay from arkose sandstone and two commercial bentonites) materials that were mixed in different proportions. The separation of mineral materials from a common and abundant natural source, for soil protection purposes, is proposed as an economic and environmentally efficient practice. The liner qualities were compared for their mineralogical, physicochemical and major ions transport and adsorption properties. Although all samples fulfilled hydraulic conductivity requirements, the addition of bentonite to arkose sandstone was determined to be an effective strategy to decrease the permeability of the soil and to improve the pollutants retention. The clay materials from arkose sandstone also contributed to pollutant retention by a significant improvement of the cation exchange capacity of the bulk material. However, the mixtures prepared with clay materials from the arkose, exhibited a slight increase of hydraulic conductivity. This effect has to be further evaluated.

The performance of natural clay as a barrier to the diffusion of municipal solid waste landfill leachates.

In this paper, the diffusion of solutes in natural clay from a concentrated solution consisting primarily of ammonium, sodium and chloride ions at a pH level of 8 was studied and was based on an existing 20-year-old landfill. Contaminant transport through clay liners was predicted using transport and reaction geochemical codes to help explain the experimental data. The model predicted the chloride anion diffusion and cation exchange processes for three different experiments: (1) small-scale interactions in compacted clay, (2) 1:1 European Union (EU) Directive demonstration experiments (0.5-m-thick clay barrier), and (3) analysis of a bore hole with core recovery drilled in an old landfill located above a similar type of clay as that studied in (1) and (2). Orders of magnitude between 10(-10) and 10(-9) m(2) s(-1) were used for the apparent diffusion coefficient to fit the chloride profiles at the different scales; however, at larger space and time scales, diffusion was retarded due to the presence of more consolidated, non-mechanically disturbed clay materials at large depths in a natural clay-rock emplacement.

Bio-nanocomposites by assembling of gelatin and layered perovskite mixed oxides.

A new class of bio-nanocomposites based on hybrid gelatin-perovskite hydrogels was prepared by mixing exfoliated perovskite-tetraalkylammonium species in aqueous suspensions with gelatin solutions. Colloidal nanosheets derived from the CsCa2Nb3O10 layered perovskite re-stacked in the gelatin solutions give bio-nanocomposite materials with different content in the inorganic moiety. These films can be easily processed as homogeneous self-supported films. The partial exfoliation of the pristine mixed oxide is produced from alkylammonium exchanged phases, being the tetraalkylammonium ions (tetraethylammonium, TEA+) an efficient intermediate to give the colloid phase constituted by well exfoliated materials useful to generate homogeneous films. The nanosheets are highly oriented in the bio-nanocomposite films in agreement with the XRD patterns and the FTIR dichroism. This orientation could be considered as a characteristic of this type of hybrid materials leading to new potential applications. In this way, we have observed that the assembling of perovskite to gelatin produces a greater increase of the dielectric permittivity than the dielectric loss in the studied samples.