Recovery of the energy contained in biogas will be essential in coming years to reduce greenhouse gas emissions and our current dependence on fossil fuels. The elimination of H2S is a priority to ...avoid equipment corrosion, poisoning of catalytic systems and SO2 emissions in combustion engines. This review describes the advances made in this technology using fixed biomass bioreactors (FBB) and suspended growth bioreactors (SGB) since the first studies in this field in 2008. Anoxic desulfurization has been studied mainly in biotrickling filters (BTF). Elimination capacities (EC) up to 287 gS m−3 h−1 have been achieved, with a removal efficiency (RE) of 99%. Both nitrate and nitrite have been successfully used as electron acceptor. SGBs can solve some operational problems present in FBBs, such as clogging or nutrient distribution issues. However, they present greater difficulties in gas-liquid mass transfer, although ECs of up to 194 gS m−3 h−1 have been reported in both gas-lift and stirred tank reactors. One of the major disadvantages of using anoxic biodesulfurization compared to aerobic biodesulfurization is the need to provide reagents (nitrates and/or nitrites), with the consequent increase in operating costs. A solution proposed in this respect is the use of nitrified effluents, some ammonium-rich effluents nitrified include landfill leachate and digested effluent from the anaerobic digester have been tested successfully. Among the microbial diversity found in the bioreactors, the genera Thiobacillus, Sulfurimonas and Sedimenticola play a key role in anoxic removal of H2S. Finally, a summary of future trends in technology is provided.
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•Anoxic biodesulfurization is a rising process given its high elimination capacities.•Simultaneous removal of H2S from biogas and NH4+ from other effluents is enabled.•The use of suspended growth and fixed biomass bioreactors is possible.•The oxidation product (S0/SO42−) is mainly determined by the nitrogen-sulfur ratio.•The technology was recently validated at TRL 7 but more studies are needed.
Drought will reduce global crop production by >10% in 2050 substantially worsening global malnutrition. Breeding for resistance to drought will require accessing crop genetic diversity found in the ...wild accessions from the driest high stress ecosystems. Genome-environment associations (GEA) in crop wild relatives reveal natural adaptation, and therefore can be used to identify adaptive variation. We explored this approach in the food crop
L., characterizing 86 geo-referenced wild accessions using genotyping by sequencing (GBS) to discover single nucleotide polymorphisms (SNPs). The wild beans represented Mesoamerica, Guatemala, Colombia, Ecuador/Northern Peru and Andean groupings. We found high polymorphism with a total of 22,845 SNPs across the 86 accessions that confirmed genetic relationships for the groups. As a second objective, we quantified allelic associations with a bioclimatic-based drought index using 10 different statistical models that accounted for population structure. Based on the optimum model, 115 SNPs in 90 regions, widespread in all 11 common bean chromosomes, were associated with the bioclimatic-based drought index. A gene coding for an ankyrin repeat-containing protein and a phototropic-responsive NPH3 gene were identified as potential candidates. Genomic windows of 1 Mb containing associated SNPs had more positive Tajima's D scores than windows without associated markers. This indicates that adaptation to drought, as estimated by bioclimatic variables, has been under natural divergent selection, suggesting that drought tolerance may be favorable under dry conditions but harmful in humid conditions. Our work exemplifies that genomic signatures of adaptation are useful for germplasm characterization, potentially enhancing future marker-assisted selection and crop improvement.
Green Chemistry Metrics, A Review Martínez, Joel; Cortés, J. Francisco; Miranda, René
Processes,
07/2022, Volume:
10, Issue:
7
Journal Article
Peer reviewed
Open access
Attending both the United Nations Decade of Education for Sustainable Development (2005–2014) and the United Nations 2030 Agenda for Sustainable Development, this review is presented, bearing in mind ...that green chemistry is essential to contribute to sustainability. This work has compiled all the information relating to green chemistry metrics, so that stakeholders can select an appropriate model, under the Green Chemistry Protocol, to evaluate how much green is a process. The review was organized considering the following convenient sections: the mass valuation, the recognition of the human health and environmental impact, metrics using computational programs (software and spreadsheets), and finally global metrics. This review was developed by consulting the principal databases, since the appearance of the first green chemistry textbook in 1998. A massive number of references were attained involving the keywords proposed below, with six languages observed, highlighted by the English language. It is important to emphasize that the 12 Principles of Green Chemistry are conceptual and offer little quantitative information. In addition, almost all the reported metric green propositions do not consider the 12 principles and few papers offer how to obtain an appropriate evaluation about the greenness of a research. In this sense, it is convenient to note that only in the Spanish literature are there two metrics that consider all the principles. Finally, to our knowledge, and after a deep search in the literature, it is the first review that covers the different features of green chemistry: mass, environment/human health. and in some cases, the use of computational programs.
The phase III SANDPIPER study assessed taselisib (GDC-0032), a potent, selective PI3K inhibitor, plus fulvestrant in estrogen receptor-positive, HER2-negative, PIK3CA-mutant locally advanced or ...metastatic breast cancer.
Postmenopausal women with disease recurrence/progression during/after an aromatase inhibitor were randomized 2 : 1 to receive taselisib (4 mg; taselisib arm) or placebo (placebo arm) plus fulvestrant (500 mg). Stratification factors were visceral disease, endocrine sensitivity, and geographic region. Patients with PIK3CA-mutant tumors (central cobas® PIK3CA Mutation Test) were randomized separately from those without detectable mutations. The primary endpoint was investigator-assessed progression-free survival (INV-PFS) in patients with PIK3CA-mutant tumors. Secondary endpoints included objective response rate, overall survival, clinical benefit rate, duration of objective response, PFS by blinded independent central review (BICR-PFS), safety, and time to deterioration in health-related quality of life.
The PIK3CA-mutant intention-to-treat population comprised 516 patients (placebo arm: n = 176; taselisib arm: n = 340). INV-PFS was significantly improved in the taselisib {7.4 months 95% confidence interval (CI), 7.26-9.07} versus placebo arm (5.4 months 95% CI, 3.68-7.29) (stratified hazard ratio HR 0.70; 95% CI, 0.56-0.89; P = 0.0037) and confirmed by BICR-PFS (HR 0.66). Secondary endpoints, including objective response rate, clinical benefit rate, and duration of objective response, showed consistent improvements in the taselisib arm. Safety was assessed in all randomized patients who received at least one dose of taselisib/placebo or fulvestrant regardless of PIK3CA-mutation status (n = 629). Serious adverse events were lower in the placebo versus taselisib arm (8.9% versus 32.0%). There were more discontinuations (placebo arm: 2.3%; taselisib arm: 16.8%) and dose reductions (placebo arm: 2.3%; taselisib arm: 36.5%) in the taselisib arm.
SANDPIPER met its primary endpoint; however, the combination of taselisib plus fulvestrant has no clinical utility given its safety profile and modest clinical benefit.
•Taselisib, a selective PI3K inhibitor, plus fulvestrant has clinical activity in PIK3CA-mutant, ER-positive breast cancer.•SANDPIPER (NCT02340221) assessed the clinical efficacy of taselisib plus fulvestrant in advanced breast cancer.•Taselisib plus fulvestrant had an expected safety profile, but with more discontinuations than placebo plus fulvestrant.•Taselisib plus fulvestrant versus placebo plus fulvestrant significantly improved progression-free survival.
Biased sex ratios among reproductive individuals are common in plants, but the underlying mechanisms, as well as the evolutionary consequences, are not well understood. The classical theory of Düsing ...and Fisher predicts an equal primary sex ratio at seed production, based on the selective advantage of the rare sex. Biased sex ratios among reproductive plants can arise from sexual dimorphism in survival and flowering. Sex ratio biases can also be present from the seed stage; in these cases, assumptions of Düsing's and Fisher's theory, for example, random mating or demographic equilibrium, are thought to be violated.
We investigated mechanisms leading to female‐biased sex ratios in the arctic‐alpine dwarf willow Salix herbacea L. We studied sex ratios in three natural populations over 3 years as well as in 29 crosses (full‐sib families) under controlled conditions over four growth periods. We tested whether sex ratio was associated with habitat parameters (elevation and snowmelt time), or with germination, survival or flowering, and whether females and males differed in size or flowering that may cause observation bias.
We detected a strong and consistent female bias, both in natural populations (sex ratio proportion of females: 0.71–0.82) and in our controlled experiment (overall sex ratio: 0.70–0‐72). Female bias became more pronounced with increasing elevation. Our data did not support sexual dimorphism in size or flowering. Family sex ratios varied largely (from 0.25 to 1), including many female‐biased families, unbiased families and two male‐biased families. Families with lower germination, seedling establishment, survival or flowering did not have stronger female bias, indicating that intrinsically higher survival or flowering in females does not explain overall female bias.
Synthesis. Our results suggest that sex ratio bias in S. herbacea is already present in seeds and does not arise through intrinsic differences between sexes. Candidate mechanisms that can lead to both overall female bias and variation in sex ratio among families are meiotic drive or cyto‐nuclear interactions. The pioneer habit of Salix may lead to non‐equilibrium population dynamics that allow for the long‐term persistence of variable genetic sex ratio distortion systems that arise from genetic conflict.
Our results suggest that sex ratio bias in S. herbacea is already present in seeds and does not arise through intrinsic differences between sexes. Candidate mechanisms that can lead to both overall female bias and variation in sex ratio among families are meiotic drive or cyto‐nuclear interactions. The pioneer habit of Salix may lead to non‐equilibrium population dynamics that allow for the long‐term persistence of variable genetic sex ratio distortion systems that arise from genetic conflict.
1. Current changes in shrub abundance in alpine and arctic tundra ecosystems are primarily driven by climate change. However, while taller shrub communities are expanding, dwarf shrub communities ...show reductions under climate warming, and the mechanisms driving the latter (such as warming temperatures or accelerated spring snowmelt) may be complex. 2. To determine and disentangle the response of a widespread arctic-alpine prostrate dwarf shrub to both climate warming and changes in snowmelt time, we investigated phenology, clonal and sexual reproduction, leaf size, wood tissue carbon balance and leaf damage in 480 patches of Salix herbacea, along its elevational and snowmelt microhabitat range over 3 years in a space-for-time substitution. 3. Earlier snowmelt was associated with longer phenological development periods, an increased likelihood of herbivory and fungal damage, lower stem density, smaller leaves and lower end-of-season wood reserve carbohydrates. Furthermore, while early snowmelt was associated with an increased proportion of flowering stems, the proportion of fruiting stems was not, as fruit set decreased significantly with earlier snowmelt. Warmer temperatures at lower elevations were associated with lower stem numbers and larger leaves. 4. Synthesis. Our study indicates that phenology, fitness proxies and fungal/insect damage of the dwarf shrub S. herbacea are strongly influenced by snowmelt timing, and that earlier spring snowmelt reduced performance in S. herbacea. The likely mechanisms for many of the observed patterns are related to adverse temperature conditions in the early growing season. Reductions in clonal (stem number) and sexual reproduction (reduced fruit set) under earlier snowmelt, in addition to increasing damage probability, will likely lead to lower fitness and poorer performance, particularly in shrubs growing in early-exposure microhabitats. Further, we saw few concurrent benefits of higher temperatures for S. herbacea, particularly as warming was associated with lower clonal growth. As growing seasons become warmer and longer in arctic and alpine tundra ecosystems, early snowmelt is a critical mechanism reducing fitness and performance in a widespread dwarf shrub and may ultimately reduce dwarf shrub communities in tundra biomes.
Background We evaluated a new chemoimmunotherapy combination based on the anti-PD1 monoclonal antibody pembrolizumab and the pyrimidine antimetabolite gemcitabine in HER2- advanced breast cancer ...(ABC) patients previously treated in the advanced setting, in order to explore a potential synergism that could eventually obtain long term benefit in these patients. Methods HER2-negative ABC patients received 21-day cycles of pembrolizumab 200 mg (day 1) and gemcitabine (days 1 and 8). A run-in-phase (6 + 6 design) was planned with two dose levels (DL) of gemcitabine (1,250 mg/m.sup.2 DL0; 1,000 mg/m.sup.2 DL1) to determine the recommended phase II dose (RP2D). The primary objective was objective response rate (ORR). Tumor infiltrating lymphocytes (TILs) density and PD-L1 expression in tumors and myeloid-derived suppressor cells (MDSCs) levels in peripheral blood were analyzed. Results Fourteen patients were treated with DL0, resulting in RP2D. Thirty-six patients were evaluated during the first stage of Simon's design. Recruitment was stopped as statistical assumptions were not met. The median age was 52; 21 (58%) patients had triple-negative disease, 28 (78%) visceral involvement, and 27 (75%) greater than or equal to 2 metastatic locations. Progression disease was observed in 29 patients. ORR was 15% (95% CI, 5-32). Eight patients were treated greater than or equal to 6 months before progression. Fourteen patients reported grade greater than or equal to 3 treatment-related adverse events. Due to the small sample size, we did not find any clear association between immune tumor biomarkers and treatment efficacy that could identify a subgroup with higher probability of response or better survival. However, patients that experienced a clinical benefit showed decreased MDSCs levels in peripheral blood along the treatment. Conclusion Pembrolizumab 200 mg and gemcitabine 1,250 mg/m.sup.2 were considered as RP2D. The objective of ORR was not met; however, 22% patients were on treatment for greater than or equal to 6 months. ABC patients that could benefit of chemoimmunotherapy strategies must be carefully selected by robust and validated biomarkers. In our heavily pretreated population, TILs, PD-L1 expression and MDSCs levels could not identify a subgroup of patients for whom the combination of gemcitabine and pembrolizumab would induce long term benefit. Trial registration ClinicalTrials.gov and EudraCT (NCT03025880 and 2016-001,779-54, respectively). Registration dates: 20/01/2017 and 18/11/2016, respectively. Keywords: Pembrolizumab, Chemotherapy, HER2-negative, Advanced breast cancer, TILs, PD-L1, MDSCs
The optimal performance of a hydroelectric power plant depends on accurate monitoring and well-functioning sensors for data acquisition. This study proposes the use of artificial neural networks ...(ANNs) to estimate the Pelton turbine shaft power of a 10 kW micro-hydropower plant. In the event of a failure of the sensor measuring the torque and/or rotational speed of the Pelton turbine shaft, the synthetic turbine shaft power data generated by the ANN will allow the turbine output power to be determined. The experimental data were obtained by varying the operating conditions of the micro-hydropower plant, including the variation of the input power to the electric generator and the variation of the injector opening. These changes consequently affected the flow rate and the pressure head at the turbine inlet. The use of artificial neural networks (ANNs) was deemed appropriate due to their ability to model complex relationships between input and output variables. The ANN structure comprised five input variables, fifteen neurons in a hidden layer and an output variable estimating the Pelton turbine power. During the training phase, algorithms such as Levenberg–Marquardt (L–M), Scaled Conjugate Gradient (SCG) and Bayesian were employed. The results indicated an error of 0.39% with L–M and 7% with SCG, with the latter under high-flow and -energy consumption conditions. This study demonstrates the effectiveness of artificial neural networks (ANNs) trained with the Levenberg–Marquardt (L–M) algorithm in estimating turbine shaft power. This contributes to improved performance and decision making in the event of a torque sensor failure.
Mint (
L., Lamiaceae) is a strongly scented herb of the family Lamiaceae that is grown mostly by clonal propagation, making it a valuable species for the study of somaclonal variation and its ...phenotypic consequences. The recent introduction of a few species of mint in South America, followed by a presumably rampant propagation, make this region particularly ideal for studying the extent of somaclonal genetic diversity. Hence, the objective of this work was to offer a preliminary characterization of somaclonal genetically coding diversity of the mint in the northern Andes in order to address the question of whether somaclonal variants may have emerged despite relatively recent introductions in a region where mint is not native. A total of 29 clonally propagated specimens, collected in mint export farms in the province of Antioquia, a major region for mint production in the northwest Andes of Colombia, were genotyped using RNA sequencing (RNA-Seq). SNP calling was carried out from the leaves' transcriptome profiles of each plant by combining the GATK4 and TRINITY protocols, obtaining a total of 2033 loci across 912 transcripts with a minimum read depth of 20X and 4% of missing data. Unsupervised machine learning algorithms considered the
-means, AGNES and UPGMA approaches, all of which suggested three genetic clusters for
and a unique cluster for
. The results indicate that at least two different origins of
reached the eastern region of the Antioquia province, clonally propagated in the locality ever since for local consumption and export. One of these ancestries had more population structure, possibly due to environmental or anthropological pressures that intervened in the fragmentation of this genetic group or to a higher somaclonal mutation rate. This work offers a first step into the study of the accumulation and transmission of presumably quasi-neutral somatic mutations at coding regions in an herbaceous clonally propagated scented species such as mint, likely favored by an expected population expansion after its Andean introduction. These ad hoc hypotheses warrant further study as part of future research.
Leveraging innovative tools to speed up prebreeding and discovery of genotypic sources of adaptation from landraces, crop wild relatives, and orphan crops is a key prerequisite to accelerate genetic ...gain of abiotic stress tolerance in annual crops such as legumes and cereals, many of which are still orphan species despite advances in major row crops. Here, we review a novel, interdisciplinary approach to combine ecological climate data with evolutionary genomics under the paradigm of a new field of study: genome–environment associations (GEAs). We first exemplify how GEA utilizes
in situ
georeferencing from genotypically characterized, gene bank accessions to pinpoint genomic signatures of natural selection. We later discuss the necessity to update the current GEA models to predict both regional- and local- or micro-habitat–based adaptation with mechanistic ecophysiological climate indices and cutting-edge GWAS-type genetic association models. Furthermore, to account for polygenic evolutionary adaptation, we encourage the community to start gathering genomic estimated adaptive values (GEAVs) for genomic prediction (GP) and multi-dimensional machine learning (ML) models. The latter two should ideally be weighted by
de novo
GWAS-based GEA estimates and optimized for a scalable marker subset. We end the review by envisioning avenues to make adaptation inferences more robust through the merging of high-resolution data sources, such as environmental remote sensing and summary statistics of the genomic site frequency spectrum, with the epigenetic molecular functionality responsible for plastic inheritance in the wild. Ultimately, we believe that coupling evolutionary adaptive predictions with innovations in ecological genomics such as GEA will help capture hidden genetic adaptations to abiotic stresses based on crop germplasm resources to assist responses to climate change.
“I shall endeavor to find out how nature’s forces act upon one another, and in what manner the geographic environment exerts its influence on animals and plants. In short, I must find out about the harmony in nature” Alexander von Humboldt—
Letter to Karl Freiesleben, June 1799
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