El Niño–Southern Oscillation (ENSO)-driven hypersedimentation in the Poechos Reservoir, northern Peru

Although extreme El Niño events (EENEs) have always impacted hydrological anomalies and sediment transport in South America, their intensification by global warming and their association with changes in human activities and land cover after humid periods may lead to the acceleration of sediment transfers in river systems and dam reservoirs. This situation may threaten soil and water resources in arid and semiarid regions highly dependent on water originating from large dams. In this study, we investigated the sediment sequence accumulated in the Poechos Reservoir (northern Peru) and provided a retrospective reconstruction of the interactions of El Niño–Southern Oscillation (ENSO), agricultural practices and vegetation cover changes with sediment dynamics (1978–2019). To this end, a sediment core was dated and characterized by physical and chemical analyses (e.g., scanner tomography, X-ray fluorescence, particle size analysis) to estimate the evolution of sedimentation rates and changes in sediment sources during the last 5 decades. Sediment tracing results indicated the occurrence of changes in sediment sources associated with positive and negative phases of the Eastern Pacific index with a greater contribution of the lowland dry-forest area in comparison to that of the Andean area to sediment during the El Niño events (mean contribution of 76 %; up to 90 % during the coastal El Niño events (CENEs) of 2016–2017). This source contribution was mostly controlled by the stationary rainfall occurring during the EENEs in the lowland dry-forest area characterized by a low vegetation cover. Overall, after an extreme phase of ENSO, like after the EENE 1982–1983, the normal discharges and persistent sediment supplies from the middle- and upper-catchment parts led to river aggradation and the storage of substantial amounts of sediment in alluvial plains. In the absence of a significant EENE between 1983 and 1997, the large volume of sediment stored in the alluvial plains was exported by the EENE 1997–1998 resulting in an increase in sedimentation rate of 140 % after 1997 with a significant aggradation of the deltaic zone of the reservoir. In addition to the impact of extreme climate events on sediment dynamics, the development of agriculture along the riverine system after an extreme phase of ENSO increased the availability of sediments in the main channel of the rivers, easily transported by the next EENE. This study suggests that intensification of human activities associated with a higher frequency of extreme rainfall events amplified the quantity of sediment transported by the river system, which will significantly decrease the lifespan of the reservoir, which is essential to meeting the freshwater demands of the farmers and the populations living in this arid and semiarid region.</p

Three kinematical methods to identify local galactic structures

Method one: by combining a sampling parameter related to an isolating integral of the stellar motion, an optimisation of the mixture approach, and a maximisation of the partition entropy for the constituent populations of the stellar sample. Method two: by segregating into different kinematical components in terms of the stellar orbital parameters. Method three: by approaching a maximum entropy velocity distribution to samples selected in terms of stellar eccentricity layers. Working samples: HIPPARCOS and Geneva-Copenhagen survey catalog. Results: kinematical characterisation of large-scale structures, such as thin disc, thick disc and halo, and identification of small-scale structures, such as moving groups in the solar neighbourhood. Consequences: confirmation of the Titius-Bode-like law for radial velocity dispersions and explanation of the apparent vertex deviation of the disc from the swinging of two major kinematic groups around the LSR, by predicting a continuously changing orientation of the disc pseudo ellipsoid.Postprint (published version

An economic, perception and biophysical approach to the use of oat straw as mulch in Mediterranean rainfed agriculture land

Soil erosion is a key cause of land degradation in agriculture lands; and it is a worldwide threat that must be solved by means of nature-based strategies to be able to achieve sustainability. The use of mulches can be a solution, but there is a lack of information on long-term effects of the use of straw. Furthermore, little is known about the perception of farmers and the economic cost on the implantation of straw as a conservation measure. Eight paired plots were selected in Sierra de Enguera on an agriculture field to determine the effect of straw cover on soil erosion. Four plots were tilled three times per year (Control) and four plots were not ploughed and 0.125 kg m−2 y−1 of oat straw cover was applied yearly (Straw). The plots were established in 2002, and runoff and sediment was continuously collected after each rainfall event from 2004 till 2014 when the two managements were applied. The results show an immediate effect of the straw mulches as in these plots the runoff (from 7.7 till 5.9%) and soil erosion (from 47 till 26 Mg ha−1 y−1) was reduced already in the first year. The combined effect of the use of straw yearly and the no-tillage strategy resulted in a reduction of the sediment yield, and 11 years later soil erosion rates were two orders of magnitude lower than in the control plot. However, the perception of the farmers on the use of straw is very negative and they claim that subsidies need to be implemented, as the cost of straw mulch is 1.9 times more expensive than traditional tillage

The Possible Role of Epigenetics in Gestational Diabetes: Cause, Consequence, or Both

Gestational diabetes mellitus (GDM) is defined as the glucose intolerance that is not present or recognized prior to pregnancy. Several risk factors of GDM depend on environmental factors that are thought to regulate the genome through epigenetic mechanisms. Thus, epigenetic regulation could be involved in the development of GDM. In addition, the adverse intrauterine environment in patients with GDM could also have a negative impact on the establishment of the epigenomes of the offspring

A Hybrid Coral Reefs Optimization – Variable Neighborhood Search Approach for the Unequal Area Facility Layout Problem

The Unequal Area Facility Layout Problem (UA-FLP) is a relevant optimization problem related to industrial design, that deals with obtaining the most effective allocation of facilities, that make up the rectangular manufacturing plant layout. The UA-FLP is known to be a hard optimization problem, where meta-heuristic approaches are a good option to obtain competitive solutions. Many of these computational approaches, however, usually fall into local optima, and suffer from lack of diversity in their population, mainly due to the huge search spaces and hard fitness landscapes produced by the traditional representation of UA-FLP. To solve these issues, in this paper we propose a novel hybrid meta-heuristic approach, which combines a Coral Reefs Optimization algorithm (CRO) with a Variable Neighborhood Search (VNS) and a new representation for the problem, called Relaxed Flexible Bay Structure (RFBS), which simplifies the encoding and makes its fitness landscape more affordable. Thus, the use of VNS allows more intensive exploitation of the searching space with an affordable computational cost, as well as the RFBS allows better management of the free space into the plant layout. This combined strategy has been tested over a set of UA-FLP instances of different sizes, which have been previously tackled in the literature with alternative meta-heuristics. The tests results show very good performance in all cases

A novel multi-objective Interactive Coral Reefs Optimization algorithm for the Unequal Area Facility Layout Problem

The Unequal Area Facility Layout Problem (UA-FLP) has been widely analyzed in the literature using several heuristics and meta-heuristics to optimize some qualitative criteria, taking into account different restrictions and constraints. Nevertheless, the subjective opinion of the designer (Decision Maker, DM) has never been considered along with the quantitative criteria and restrictions. This work proposes a novel approach for the UA-FLP based on an Interactive Coral Reefs Optimization (ICRO) algorithm, which combines the simultaneous consideration of both quantitative and qualitative (DM opinion) features. The algorithm implementation is explained in detail, including the way of jointly considering quantitative and qualitative aspects in the fitness function of the problem. The experimental part of the paper illustrates the effect of including qualitative aspects in UA-FLP problems, considering three different hard UA-FLP instances. Empirical results show that the proposed approach is able to incorporate the DM preferences in the obtained layouts, without affecting much to the quantitative part of the solutions

Antinociceptive effects of tetrazole inhibitors of endocannabinoid inactivation: Cannabinoid and non-cannabinoid receptor-mediated mechanisms

Background and purpose: Tetrazoles were recently developed as inhibitors of the cellular uptake of the endocannabinoid anandamide or of its hydrolysis by fatty acid amide hydrolase (FAAH), but were proposed to act also on non-endocannabinoid-related serine hydrolases. Experimental approach: We tested, in a model of inflammatory pain induced in mice by formalin, five chemically similar inhibitors: (i) OMDM119 and OMDM122, two potent carbamoyl tetrazole FAAH inhibitors with no effect on anandamide uptake; (ii) LY2183240, a carbamoyl tetrazole with activity as both FAAH and uptake inhibitor; (iii) OMDM132, a non-carbamoyl tetrazole with activity only as uptake inhibitor and iv) OMDM133, a non-carbamoyl tetrazole with no activity at either FAAH or uptake. Results: All compounds (2.5-10 mg kg -1, i.p.) inhibited the second phase of the nocifensive response induced by intraplantar injection of formalin. The effects of OMDM119, OMDM122 and OMDM133 were not antagonized by pretreatment with cannabinoid CB 1 receptor antagonists, such as rimonabant or AM251 (1-3 mg kg -1, i.p.). The effects of LY2183240 and OMDM132 were fully or partially antagonized by rimonabant, respectively, and the latter compound was also partly antagonized by the CB 2 receptor antagonist, AM630. Conclusions and implications: (i) non-FAAH hydrolases might be entirely responsible for the antinociceptive activity of some, but not all, tetrazole FAAH inhibitors, (ii) the presence of a carbamoylating group is neither necessary nor sufficient for such compounds to act through targets other than FAAH and (iii) inhibition of anandamide uptake is responsible for part of this antinociceptive activity, independently of effects on FAAH. © 2008 Macmillan Publishers Limited All rights reserved

A novel Island Model based on Coral Reefs Optimization algorithm for solving the unequal area facility layout problem

This paper proposes a novel approach to address the Unequal Area Facility Layout Problem (UA-FLP), based on the combination of both an Island Model and a Coral Reefs Optimization (CRO) algorithm. Two different versions of this Island Model based on Coral Reefs Optimization Algorithm (IMCRO) are proposed and applied to the UA-FLP. The structure of flexible bays has been selected as effective encoding to represent the facility layouts within the algorithm. The two versions of the proposed approach have been tested in 22 UA-FLP cases, considering small, medium and large size categories. The empirical results obtained are compared with previous state of the art algorithms, in order to show the performance of the IMCRO. From this comparison, it can be extracted that both versions of the proposed IMCRO algorithm show an excellent performance, accurately solving the UA-FLP instances in all the size categories

Directly imaging spin polarons in a kinetically frustrated Hubbard system

The emergence of quasiparticles in quantum many-body systems underlies the rich phenomenology in many strongly interacting materials. In the context of doped Mott insulators, magnetic polarons are quasiparticles that usually arise from an interplay between the kinetic energy of doped charge carriers and superexchange spin interactions. However, in kinetically frustrated lattices, itinerant spin polarons - bound states of a dopant and a spin-flip - have been theoretically predicted even in the absence of superexchange coupling. Despite their important role in the theory of kinetic magnetism, a microscopic observation of these polarons is lacking. Here we directly image itinerant spin polarons in a triangular lattice Hubbard system realised with ultracold atoms, revealing enhanced antiferromagnetic correlations in the local environment of a hole dopant. In contrast, around a charge dopant, we find ferromagnetic correlations, a manifestation of the elusive Nagaoka effect. We study the evolution of these correlations with interactions and doping, and use higher-order correlation functions to further elucidate the relative contributions of superexchange and kinetic mechanisms. The robustness of itinerant spin polarons at high temperature paves the way for exploring potential mechanisms for hole pairing and superconductivity in frustrated systems. Furthermore, our work provides microscopic insights into related phenomena in triangular lattice moir\'{e} materials.Comment: 7 pages (4 figures) + 6 pages methods (7 figures

Policies can help to apply successful strategies to control soil and water losses. The case of chipped pruned branches (CPB) in Mediterranean citrus plantations

There is a need to devise management strategies that control soil and water losses in agriculture land to allow the design of proper policies to achieve sustainability. It is the responsibility of scientists to work with other actors to co-construct strategies that will lead to sustainable land-use policies. Using chipped pruned branches (CPB) as mulch can be a viable option because they represent local (in situ) organic material that can restore soil nutrients and organic matter. This research assesses: i) the perception of farmers towards different types of management strategies and CPB's costs; ii) the biomass yield of citrus branches and the impact of CPB on soil properties; iii) how CPB affects soil erosion and runoff generation in citrus plantations; and, iv) a discussion about how to favour the use of CPB thought successful policies. To achieve those goals we carried out: i) one-hundred interviews to assess the perception of farmers and twelve interviews to assess the economic balance of twelve land owners; ii) soil was sampled at 0-2 and 4-6 cm depths; iii) pruned material was surveyed for 40 trees; and iv) forty rainfall simulation experiments (55mmh−1) were carried out in two citrus plantations at paired sites (Control versus CPB), in La Costera District in Eastern Spain. Forty circular (0.25m2) plots were installed in four rows (4×5=20 plots) in control (CON) and CPB plots (20+20=40 plots) to perform the rainfall simulations over one hour. The cost of chipping ranged from 102 to 253 ha−1, and was related to the size of the farm. The soil quality, runoff and erosion assessment showed that CPB is a suitable strategy. CPB increased organic matter from 1.3% to 2.9% after 10 years in the 0-2 cm depth layer, while the 4-6 cm layer was largely not affected (OM moved from 1.1 to 1.3% after 10 years), and soil bulk density showed a similar trend: a decrease from 1.36 to 1.16 g cm−3 in the surface layer with no change in the subsurface layer. The hydrological and erosional responses were different between CON and CPB. The CON plots initiated ponding (40 s) and runoff (107 s) earlier than the CPB plots (169 and 254 s, respectively); and runoff discharge was 60% in CON vs 43% in CPB plots. Sediment concentration was four times larger in the CON plots than in the CPB (11.3 g l−1 vs 3 g l−1), and soil erosion was 3.8 Mg ha−1 h-1 vs 0.7 Mg ha−1 h−1. CPB mulches were effective at controlling soil and water losses in Mediterranean citrus plantations as they showed the relationship between vegetation/litter cover and soil erosion rates. However, the farmer's perception survey showed that the use of CPB was not welcomed nor accepted by the farmers. Policies that aim to promote CPB as soil conservation mulch need to be promoted by subsidies as the farmers requested, and by education to demonstrate the positive effects of CPB to of the farming community