Do birds select the plastics debris used for nest construction? A case study in a Mediterranean agricultural landscape.

Plastic pollution is becoming a global problem due to its ubiquitous occurrence and the impacts detected for many species. However, the research about plastics in nests of terrestrial bird species has remained relatively overlooked in comparison to those devoted to marine ecosystems. Here we study the occurrence and patterns of use of anthropogenic material in nests of two passerine birds, the Eurasian magpie (Pica pica) and the European serin (Serinus serinus), breeding in an orange tree cultivation in Mediterranean Spain. Our results show that both species use extensively plastic debris as nest material; almost 71% of the European serin nests and 96% of nests of Eurasian magpies contained plastic debris. Furthermore, by analyzing the plastic debris availability in the agricultural landscape surveyed we confirmed a selection pattern in the two species. Thus, both species preferably select plastic filaments over other plastic debris. The Eurasian magpie does not select plastic based on size or color but the European serin avoid black plastics prefer smaller fragments in comparison to the average size available. Moreover, we suggest the apparent similarity of plastic filaments with the natural materials typically used by these species, as well as how they use the plastic in their nests could influence their selection behavior. More studies focused on terrestrial birds inhabiting human modified habitats could offer a deeper approach to how plastic debris interacts with wildlife in different ways.

Side-Selective Solid-Phase Metallaphotoredox N(in)-Arylation of Peptides.

Postsynthetic diversification of peptides through selective modification of endogenous amino acid side chains has enabled significant advances in peptide drug discovery while expanding the biological and medical chemistry space. However, current tools have been focused on the modification of reactive polar and ionizable side chains, whereas the decoration of aromatic systems (e.g., the N(in) of the tryptophan) has been a long-standing challenge. Here, we introduce metallaphotocatalysis in solid-phase peptide synthesis for the on-resin orthogonal N-arylation of relevant tryptophan-containing peptides. The protocol allows the chemoselective introduction of a new C(sp2)-N bond at the N(in) of tryptophan in biologically active protected peptide sequences in the presence of native redox-sensitive side chains. The fusion of metallaphotocatalysis with solid-phase peptide synthesis opens new perspectives in diversifying native amino acid side chains.

Soil Thermophiles and Their Extracellular Enzymes: A Set of Capabilities Able to Provide Significant Services and Risks.

During this century, a number of reports have described the potential roles of thermophiles in the upper soil layers during high-temperature periods. This study evaluates the capabilities of these microorganisms and proposes some potential consequences and risks associated with the activity of soil thermophiles. They are active in organic matter mineralization, releasing inorganic nutrients (C, S, N, P) that otherwise remain trapped in the organic complexity of soil. To process complex organic compounds in soils, these thermophiles require extracellular enzymes to break down large polymers into simple compounds, which can be incorporated into the cells and processed. Soil thermophiles are able to adapt their extracellular enzyme activities to environmental conditions. These enzymes can present optimum activity under high temperatures and reduced water content. Consequently, these microorganisms have been shown to actively process and decompose substances (including pollutants) under extreme conditions (i.e., desiccation and heat) in soils. While nutrient cycling is a highly beneficial process to maintain soil service quality, progressive warming can lead to excessive activity of soil thermophiles and their extracellular enzymes. If this activity is too high, it may lead to reduction in soil organic matter, nutrient impoverishment and to an increased risk of aridity. This is a clear example of a potential effect of future predicted climate warming directly caused by soil microorganisms with major consequences for our understanding of ecosystem functioning, soil health and the risk of soil aridity.

Eating in the city: Experimental effect of anthropogenic food resources on the body condition, nutritional status, and oxidative stress of an urban bioindicator passerine.

Urban areas provide a constant and predictable supply of anthropogenic processed food. The House Sparrow (Passer domesticus Linnaeus, 1758), a declining urban bioindicator species, has recently been reported to have a high level of oxidative stress, with urban diet or pollutants proposed as the potential cause. In this study, we aimed to experimentally determine the effects of two urban trophic resource types (bar snack food leftovers and pet food) on sparrows' physical condition, plasma biochemical nutritional parameters, and blood oxidative status in captivity. To exclude the potential previous effect of urban pollutants, 75 House Sparrows were captured from a rural area in SE Spain and kept in outdoor aviaries. Individuals were exposed to one of three diet treatments: control diet (fruit, vegetables, poultry grain mixture), bar snack diet (ultra-processed snacks), or cat food diet (dry pellets) for 20 days. Blood samples were collected before and after diet treatments to analyze the relative change rates of 12 variables, including physical condition, nutritional status, and oxidant-antioxidant status. A principal component analysis was run to identify gradients of variables covariation, and Generalized Linear Mixed Models were used to determine the effect of diets on each selected PC and on raw variables. The bar snack diet led to signs of anemia and malnutrition, and females tended to lose body condition. The cat food diet increased oxidative stress indicators and protein catabolism. Unbalanced urban diets can affect the body condition and nutritional physiology of House Sparrows and may also induce oxidative stress despite the absence of environmental pollution.

Photofunctional Scope of Fluorescent Dithienylethene Conjugates with Aza-Heteroaromatic Cations.

A series of dithienylethene (DTE) photoswitches with aza-heteroaromatic cationic moieties is synthesized. The switches are characterized regarding their photochemical and photophysical properties in acetonitrile and in water. The efficiency of the switching and the photostationary state composition depend on the degree of π-conjugation of the heteroaromatic systems. Thus, DTEs with acridinium-derived moieties have very low quantum yields for the ring-closing process, which is in contrast to switches with pyridinium and quinolinium moieties. All switches emit fluorescence in their open forms. The involved electronic transitions are traced back to an integrative picture including the DTE core and the cationic arms. The emission can be fine-tuned by the π-conjugation of the heteroaromatic cations, reaching the red spectral region for DTEs with acridinium moieties. On ring-closing of the DTEs the fluorescence is not observable anymore. Theoretical calculations point to rather low-lying energy levels of the highly conjugated ring-closed DTEs, which would originate near-infrared emission (> 1200 nm). The latter is predicted to be very weak due to the concurrent non-radiative deactivation, according to the energy-gap law. In essence, an ON-OFF fluorescence switching as the result of the electrocyclic ring-closing reaction is observed.

Functional vitamin B12 deficiency: Improving methylmalonic acid reference intervals in urine.

BACKGROUND-AIM: Most laboratory requests focus on the detection of possible vitamin B12 deficiency. In this context, methylmalonic acid (MMA) is reported as the best biomarker. The aim of our study was to establish the biological reference interval for MMA in urine, and assess the influence of age, sex, and vitamin B12 status on MMA concentrations. METHODS: This is a prospective observational study considering individuals with normal results for blood count and liver and kidney function. Individuals who presented supplementation, any pathology or treatment that could cause cobalamin metabolism disorders, and pregnant women were excluded. Likewise, individuals whose vitamin B12 result presented antibody-mediated interference were excluded. Individuals were grouped by age-group and sex. Reference intervals were determined by non-parametric calculation (percentiles 1-99). RESULTS: It was established a single reference interval [0.52 (CI90%: 0.50-0.54) - 5.75 (CI90%: 5.57-6.17) mmolMMA/mol creatinine], with 100 % of individuals with MMA above the upper limit of reference presenting a total vitamin B12 concentration ≤ 238 pmol/L. CONCLUSION: The establishment of optimal reference intervals for methylmalonic acid excretion in urine is crucial in individuals with a suspicion of functional vitamin B12 deficiency. However, the possibility of establishing a cut-off value for total vitamin B12 suggesting subclinical deficiency remains a challenge for this magnitude.

Plastic Debris in Nests of Two Water Bird Species Breeding on Inland Saline Lakes in a Mediterranean Biosphere Reserve.

Despite more studies being carried out to know the impacts associated with plastic debris and much effort being spent on marine ecosystems, the impacts of plastics on terrestrial and freshwater species remain largely unknown. Here, we explored the presence of anthropogenic materials in nests of two wader species, the gull-billed tern (Gelochelidon nilotica) and the black-winged stilt (Himantopus himantopus), breeding on the inland salt lakes in the "La Mancha Húmeda" Biosphere Reserve, Central Spain. We revealed the presence of anthropogenic debris, mainly macroplastics (>5 mm), in 2.4% and 12.5% of the sampled nests of the gull-billed tern and the black-winged stilt, respectively. The fragments found in nests ranged from 8 mm to 257 mm for the gull-billed tern and from 7 mm to 19 mm for the black-winged stilt. This debris showed no clear pattern of color or size and probably originated both in the agricultural activities in the surroundings and domestic refuse. Although we did not detect any pernicious impacts on adults or chicks (e.g., entangled, injured, or dead individuals), the presence of plastics and other human waste directly placed in nests located in a protected area should warn us about the ubiquity of these pollutants, and the endocrine and immunological effects, among others, that may reduce the recruitment of new animals to the population should be assessed.

Metal-Mediated Organocatalysis in Water: Serendipitous Discovery of Aldol Reaction Catalyzed by the [Ru(bpy)2(nornicotine)2]2+ Complex.

The [Ru(bpy)2(Nor)2]2+ complex (Nor = nornicotine) is an efficient catalyst for the aldol reaction of acetone with activated benzaldehydes in a buffered aqueous solution. The metal plays the role of an activator for the nornicotine organocatalyst ligands. The resulting catalytic activity is potentiated by a factor of about 4.5 as compared to free nornicotine. Similar rate enhancements can be achieved by using Zn(II) cations as the activator. The observations are rationalized with the reduced basicity of the pyrrolidine N in nornicotine due to the enhanced electron withdrawal of the metal-complexed pyridyl moiety.

Photooxidation Responsive Elastin-Like Polypeptide Conjugates for Photodynamic Therapy Application.

Stimuli-responsive recombinant elastin-like polypeptides (ELPs) are artificial protein polymers derived from the hydrophobic domain of tropoelastin that have attracted significant interest for drug delivery and tissue engineering applications. In the present study, we have conjugated a photosensitizer (PS) to a hydrophobic methionine-containing ELP scaffold, which upon reaction with singlet oxygen (1O2) is transformed into a hydrophilic sulfoxide derivative facilitating the disassembly of photosensitizer-delivery particles during the photodynamic therapy (PDT) process. A peripherally substituted carboxy-Zn(II)-phthalocyanine derivative (TT1) bearing a carboxyl group directly linked to the Pc-ring, and presenting an absorption maximum around 680 nm, was selected as PS which simultaneously acted as a photooxidation catalyst. A TT1-ELP[M1V3-40] conjugate was prepared from ELP[M1V3-40] modified with an alkyne group at the N-terminal chain end, and from TT1-amide-C3-azide by copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) reaction. This innovative model photooxidation sensitive PS delivery technology offers promising attributes in terms of temperature-controlled particle formation and oxidation-triggered release, narrow molar mass distribution, reproducibility, scalability, non-immunogenicity, biocompatibility, and biodegradability for pharmaceutical applications in an effort to improve the clinical effectiveness of PDT treatments.

Electrochemical Installation of CFH2 -, CF2 H-, CF3 -, and Perfluoroalkyl Groups into Small Organic Molecules.

Electrosynthesis can be considered a powerful and sustainable methodology for the synthesis of small organic molecules. Due to its intrinsic ability to generate highly reactive species under mild conditions by anodic oxidation or cathodic reduction, electrosynthesis is particularly interesting for otherwise challenging transformations. One such challenge is the installation of fluorinated alkyl groups, which has gained significant attention in medicinal chemistry and material science due to their unique physicochemical features. Unsurprisingly, several electrochemical fluoroalkylation methods have been established. In this review, we survey recent developments and established methods in the field of electrochemical mono-, di-, and trifluoromethylation, and perfluoroalkylation of small organic molecules.

Biocompatible Photoinduced Alkylation of Dehydroalanine for the Synthesis of Unnatural α-Amino Acids.

A site-selective alkylation of dehydroalanine to access protected unnatural amino acids is described. The protocol is characterized by the wide nature of alkyl radicals employed, mild conditions, and functional group compatibility. This protocol is further extended to access peptides, late-stage functionalization of pharmaceuticals, and enantioenriched amino acids.

Recreational noise pollution of traditional festivals reduces the juvenile productivity of an avian urban bioindicator.

Noise is a pollutant of emergent concern for ecologists and conservation biologists. Recreational noise pollution, especially unpredictable and intermittent sounds, and its effects on wildlife and biodiversity have been poorly studied. Researchers have paid very little attention to the effect of noisy traditional festivals (fireworks and powder-guns). This study aimed to explore the effect of these recreational activities on the juvenile productivity of an urban avian bioindicator: the house sparrow. We studied five pairs of localities in the Valencia Region (E Spain) with noisy traditional festivals. Each pair was composed of one locality with festivals during the breeding season and the closest similar locality, but with festivals outside the reproductive period (controls). Both locality types were sampled twice each spring (May-June of 2019 and 2020). Sampling dates were selected as 15 and 30 days after noisy festivals ended, while the control localities were sampled 1 day after the census of their correspondent town pair with noisy breeding season festivals. The ratio of the juveniles/adults detected during surveys in the influence area of festivals (100-m buffer around the parades route) was used as a house sparrow breeding success proxy. Data were analysed using GLMM: year (2019/2020), festivals season (breeding/non-breeding), survey (15/30 days), and their interactions were included as fixed factors. Pair of localities and locality nested within the pair were random factors. In 2019, juvenile productivity was lower in the towns with noisy traditional festivals during the breeding season than in the control towns. The 2020 festivals were cancelled due to COVID-19. In spring 2020, house sparrow juvenile productivity was the same in both town groups. Lockdown did not increase this species' juvenile productivity in the control localities in 2020 versus 2019.

Post-synthetic functionalization of tryptophan protected peptide sequences through indole (C-2) photocatalytic alkylation.

We report a selective, mild, and efficient C-H functionalization of tryptophan and tryptophan-containing peptides with activated α-bromo-carbonyl compounds under visible-light irradiation. The protocol efficiency is outlined by the wide substrate scope and excellent tolerance of sensitive functional groups present in the amino acid side chains. The method can be successfully extended to access pharmaco-peptide conjugate scaffolds.

Influence of water availability and temperature on estimates of microbial extracellular enzyme activity.

Soils are highly heterogeneous and support highly diverse microbial communities. Microbial extracellular enzymes breakdown complex polymers into small assimilable molecules representing the limiting step of soil organic matter mineralization. This process occurs on to soil particles although currently it is typically estimated in laboratory aqueous solutions. Herein, estimates of microbial extracellular enzyme activity were obtained over a broad range of temperatures and water availabilities frequently observed at soil upper layers. A Pseudomonas strain presented optimum extracellular enzyme activities at high water activity whereas a desiccation resistant bacterium (Deinococcus) and a soil thermophilic isolate (Parageobacillus) showed optimum extracellular enzyme activity under dried (i.e., water activities ranging 0.5-0.8) rather that wet conditions. Different unamended soils presented a distinctive response of extracellular enzyme activity as a function of temperature and water availability. This study presents a procedure to obtain realistic estimates of microbial extracellular enzyme activity under natural soil conditions of extreme water availability and temperature. Improving estimates of microbial extracellular enzyme activity contribute to better understand the role of microorganisms in soils.

Environmental factors affect the response of microbial extracellular enzyme activity in soils when determined as a function of water availability and temperature.

Microorganisms govern soil carbon cycling with critical effects at local and global scales. The activity of microbial extracellular enzymes is generally the limiting step for soil organic matter mineralization. Nevertheless, the influence of soil characteristics and climate parameters on microbial extracellular enzyme activity (EEA) performance at different water availabilities and temperatures remains to be detailed. Different soils from the Iberian Peninsula presenting distinctive climatic scenarios were sampled for these analyses. Results showed that microbial EEA in the mesophilic temperature range presents optimal rates under wet conditions (high water availability) while activity at the thermophilic temperature range (60°C) could present maximum EEA rates under dry conditions if the soil is frequently exposed to high temperatures. Optimum water availability conditions for maximum soil microbial EEA were influenced mainly by soil texture. Soil properties and climatic parameters are major environmental components ruling soil water availability and temperature which were decisive factors regulating soil microbial EEA. This study contributes decisively to the understanding of environmental factors on the microbial EEA in soils, specifically on the decisive influence of water availability and temperature on EEA. Unlike previous belief, optimum EEA in high temperature exposed soil upper layers can occur at low water availability (i.e., dryness) and high temperatures. This study shows the potential for a significant response by soil microbial EEA under conditions of high temperature and dryness due to a progressive environmental warming which will influence organic carbon decomposition at local and global scenarios.

Persistence of microbial extracellular enzymes in soils under different temperatures and water availabilities.

Microbial extracellular enzyme activity (EEA) is critical for the decomposition of organic matter in soils. Generally, EEA represents the limiting step governing soil organic matter mineralization. The high complexity of soil microbial communities and the heterogeneity of soils suggest potentially complex interactions between microorganisms (and their extracellular enzymes), organic matter, and physicochemical factors. Previous studies have reported the existence of maximum soil EEA at high temperatures although microorganisms thriving at high temperature represent a minority of soil microbial communities. To solve this paradox, we attempt to evaluate if soil extracellular enzymes from thermophiles could accumulate in soils. Methodology at this respect is scarce and an adapted protocol is proposed. Herein, the approach is to analyze the persistence of soil microbial extracellular enzymes at different temperatures and under a broad range of water availability. Results suggest that soil high-temperature EEA presented longer persistence than enzymes with optimum activity at moderate temperature. Water availability influenced enzyme persistence, generally preserving for longer time the extracellular enzymes. These results suggest that high-temperature extracellular enzymes could be naturally accumulated in soils. Thus, soils could contain a reservoir of enzymes allowing a quick response by soil microorganisms to changing conditions. This study suggests the existence of novel mechanisms of interaction among microorganisms, their enzymes and the soil environment with relevance at local and global levels.

Excerpts from the documents of Mexican positions and recommendations in cardiovascular diseases and COVID-19.

The recommendations in which the Mexican Society of Cardiology (SMC) in conjunction with the National Association of Cardiologists of Mexico (ANCAM) as well as different Mexican medical associations linked to cardiology are presented, after a comprehensive and consensual review and analysis of the topics related to cardiovascular diseases in the COVID-19 pandemic. Scientific positions are analyzed and responsible recommendations on general measures are given to patients, with personal care, healthy eating, regular physical activity, actions in case of cardio-respiratory arrest, protection of the patient and health personnel as well as precise indications in the use of non-invasive cardiovascular imaging, prescription of medications, care in specific topics such as systemic arterial hypertension, heart failure, arrhythmias and acute coronary syndromes, in addition to emphasizing electrophysiology, interventionism, cardiac surgery and in cardiac rehabilitation. The main interest is to provide the medical community with a general orientation on what to do in daily practice and patients with cardiovascular diseases in the setting of this unprecedented epidemiological crisis of COVID-19.

Se presentan las recomendaciones en las cuales la Sociedad Mexicana de Cardiología (SMC) en conjunto con la Asociación Nacional de Cardiólogos de México (ANCAM), así como diferentes asociaciones médicas mexicanas vinculadas con la cardiología, después de una revisión y análisis exhaustivo y consensuado sobre los tópicos relacionados con las enfermedades cardiovasculares en la pandemia de COVID-19, se analizan posturas científicas y se dan recomendaciones responsables sobre medidas generales a los pacientes, con cuidados personales, alimentación saludable, actividad física regular, acciones en caso de paro cardiorrespiratorio, la protección del paciente y del personal de salud así como las indicaciones precisas en el uso de la imagen cardiovascular no invasiva, la prescripción de medicamentos, cuidados en tópicos específicos como en la hipertensión arterial sistémica, insuficiencia cardiaca, arritmias y síndromes coronarios agudos, además de hacer énfasis en los procedimientos de electrofisiología, intervencionismo, cirugía cardiaca y en la rehabilitación cardiaca. El interés principal es brindar a la comunidad médica una orientación general sobre el quehacer en la práctica cotidiana y pacientes con enfermedades cardiovasculares en el escenario esta crisis epidemiológica sin precedentes de COVID-19.

Visible Light-Gated Organocatalysis Using a RuII -Photocage.

The light-gated organocatalysis via the release of 4-N,N-dimethylaminopyridine (DMAP) by irradiation of the [Ru(bpy)2 (DMAP)2 ]2+ complex with visible light was investigated. As model reaction the acetylation of benzyl alcohols with acetic anhydride was chosen. The pre-catalyst releases one DMAP molecule on irradiation at wavelengths longer than 455 nm. The photochemical process was characterized by steady-state irradiation and ultrafast transient absorption spectroscopy. The latter enabled the observation of the 3 MLCT state and the spectral features of the penta-coordinated intermediate [Ru(bpy)2 (DMAP)]2+ . The released DMAP catalyzes the acetylation of a wide range of benzyl alcohols with chemical yields of up to 99 %. Control experiments revealed unequivocally that it is the released DMAP which takes the role of the catalyst.

Optical Supramolecular Sensing of Creatinine.

Calix[4]pyrrole phosphonate-cavitands were used as receptors for the design of supramolecular sensors for creatinine and its lipophilic derivative hexylcreatinine. The sensing principle is based on indicator displacement assays of an inherently fluorescent guest dye or a black-hole quencher from the receptor's cavity by means of competition with the creatinine analytes. The systems were thermodynamically and kinetically characterized regarding their 1:1 binding properties by means of nuclear magnetic resonance spectroscopy (1H and 31P NMR), isothermal titration calorimetry, and optical spectroscopies (UV/vis absorption and fluorescence). For the use of the black-hole indicator dye, the calix[4]pyrrole was modified with a dansyl chromophore as a signaling unit that engages in Förster resonance energy transfer with the indicator dye. The 1:1 binding constants of the indicator dyes are in the range of 107 M-1, while hexylcreatinine showed values around (2-4) × 105 M-1. The competitive displacement of the indicators by hexylcreatinine produced supramolecular fluorescence turn-on sensors that work at micromolar analyte concentrations that are compatible with those observed for healthy as well as sick patients. The limit of detection for one of the systems reached submicromolar ranges (110 nM).

One-pot organocatalytic/multicomponent approach for the preparation of novel enantioenriched non-natural selenium-based peptoids and peptide-peptoid conjugates.

A combined organocatalytic and multicomponent synthetic approach was designed for the preparation of selenium-based peptoids and peptide-peptoid conjugates. This single-step synthetic protocol comprises the organocatalytic asymmetric insertion of phenylselenium in the aldehyde moiety followed by the Ugi four-component reaction which results in obtaining the desired compounds in good-to-moderate yields and with good-to-excellent levels of stereoselectivity.