RESUMEN
To track and control self-location, animals integrate their movements through space. Representations of self-location are observed in the mammalian hippocampal formation, but it is unknown if positional representations exist in more ancient brain regions, how they arise from integrated self-motion, and by what pathways they control locomotion. Here, in a head-fixed, fictive-swimming, virtual-reality preparation, we exposed larval zebrafish to a variety of involuntary displacements. They tracked these displacements and, many seconds later, moved toward their earlier location through corrective swimming ("positional homeostasis"). Whole-brain functional imaging revealed a network in the medulla that stores a memory of location and induces an error signal in the inferior olive to drive future corrective swimming. Optogenetically manipulating medullary integrator cells evoked displacement-memory behavior. Ablating them, or downstream olivary neurons, abolished displacement corrections. These results reveal a multiregional hindbrain circuit in vertebrates that integrates self-motion and stores self-location to control locomotor behavior.
Asunto(s)
Neuronas , Pez Cebra , Animales , Pez Cebra/fisiología , Neuronas/fisiología , Rombencéfalo/fisiología , Encéfalo/fisiología , Natación/fisiología , Homeostasis , MamíferosRESUMEN
Keloids are characterized by fibroblast hyperproliferation and excessive accumulation of extracellular matrix (ECM) and are a major global health care burden among cutaneous diseases. However, the function of long noncoding RNA (lncRNA)-mediated ECM remodeling during the pathogenesis of keloids is still unclear. Herein, we identified a long noncoding transcript, namely, lymphocyte-specific protein 1 pseudogene 5 (LSP1P5), that modulates ECM component deposition in keloids. First, high-throughput transcriptome analysis showed that LSP1P5 was selectively upregulated in keloids and correlated with more severe disease in a clinical keloid cohort. Therapeutically, the attenuation of LSP1P5 significantly decreased the expression of ECM markers (COL1, COL3, and FN1) both in vitro and in vivo. Intriguingly, an antifibrotic gene, CCAAT enhancer binding protein alpha (CEBPA), is a functional downstream candidate of LSP1P5. Mechanistically, LSP1P5 represses CEBPA expression by hijacking Suppressor of Zeste 12 to the promoter of CEBPA, thereby enhancing the polycomb repressive complex 2-mediated H3K27me3 and changing the chromosomal opening status of CEBPA. Taken together, these findings indicate that targeting LSP1P5 abrogates fibrosis in keloids through epigenetic regulation of CEBPA, revealing a novel antifibrotic therapeutic strategy that bridges our current understanding of lncRNA regulation, histone modification and ECM remodeling in keloids.
Asunto(s)
Proteínas Potenciadoras de Unión a CCAAT , Matriz Extracelular , Queloide , ARN Largo no Codificante , Queloide/genética , Queloide/metabolismo , Queloide/patología , Humanos , ARN Largo no Codificante/genética , Matriz Extracelular/metabolismo , Proteínas Potenciadoras de Unión a CCAAT/genética , Proteínas Potenciadoras de Unión a CCAAT/metabolismo , Animales , Ratones , Regulación de la Expresión Génica , Fibroblastos/metabolismo , Regiones Promotoras Genéticas , Masculino , Regulación hacia ArribaRESUMEN
A highly effective and selective FeBr3-promoted deuterium bromination/cyclization of 1,n-enynes is reported. On the one hand, the Lewis acid FeBr3 as a catalyst promotes cyclization of 1,n-enynes to afford deuterium heterocyclic frameworks with high efficiency. On the other hand, FeBr3 serves as the bromine source (with D2O as the deuterium source) to promote the formation of the desired deuterated pyrrole derivatives containing alkenyl bromide groups. This protocol provides an effective pathway to afford deuterated alkenyl brominative compounds as (Z)-isomers with high yields and selectivity, offering a new method for introducing 2H into organic compounds.
RESUMEN
In recent years, great progress has been made on the study of nanozymes with enzyme-like properties. Here, bimetallic Fe and Ni nanoclusters were anchored on the nanosheets of nitrogen-rich layered graphitic carbon nitride by one-step pyrolysis at high temperature (Fe/Ni-CN). The loading content of Fe and Ni on Fe/Ni-CN is as high as 8.0%, and Fe/Ni-CN has a high specific surface area of 121.86 m2 g-1. The Fe/Ni-CN can effectively oxidize 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2, and exhibits efficient peroxidase-like activity, leading to a 17.2-fold increase compared to pure graphitic carbon nitride (CN). Similar to the natural horseradish peroxidase (HRP), the Fe/Ni-CN nanozyme follows catalytic kinetics. The Michaelis-Menten constant (Km) value of the Fe/Ni-CN nanozyme for TMB is about 8.3-fold lower than that for HRP, which means that the Fe/Ni-CN nanozyme has better affinity for TMB. In addition, the catalytic mechanism was investigated by combination of free radical quenching experiments and density-functional theory (DFT) calculations. The results show that the high peroxidase-like activity is due to the easy adsorption of H2O2 after bimetal loading, which is conducive to the production of hydroxyl radicals. Based on the extraordinary peroxidase-like activity, the colorimetric detection of p-phenylenediamine (PPD) was constructed with a wide linear range of 0.2-30 µM and a low detection limit of 0.02 µM. The sensor system has been successfully applied to the detection of residual PPD in real dyed hair samples. The results show that the colorimetric method is sensitive, highly selective and accurate. This study provides a new idea for the efficient enhancement of nanozyme activity and effective detection of PPD by a bimetallic synergistic strategy.
Asunto(s)
Colorimetría , Grafito , Hierro , Níquel , Compuestos de Nitrógeno , Fenilendiaminas , Grafito/química , Fenilendiaminas/química , Colorimetría/métodos , Compuestos de Nitrógeno/química , Níquel/química , Hierro/química , Peróxido de Hidrógeno/análisis , Peróxido de Hidrógeno/química , Nitrilos/química , Límite de Detección , Catálisis , Bencidinas/químicaRESUMEN
This study examined the effect of combining visual and olfactory cues to attract oriental fruit flies (OFFs). Six different colored light-emitting diodes (LEDs) served as a visual attractant and methyl eugenol served as olfactory bait to lure male flies. An internet of things (IoT)-based pest monitoring system, consisting of sensor nodes, a gateway, and automatic counting traps, was deployed in the field to automatically collect environmental data and pest counts. The results of the calibrated experiments indicated that green, yellow, or red LEDs exhibited better performance in attracting flies than white, purple, or blue LEDs or no LEDs. With an accurate combination of visual and olfactory cues, the proposed IoT-based pest monitoring system may be an effective tool in agricultural pest management, given its advantages for efficiently capturing OFFs in a labor and time saving manner, providing accurate information regarding increases in pest populations, and enabling long-term, real-time data collection.
Asunto(s)
Internet de las Cosas , Tephritidae , Masculino , Animales , Señales (Psicología) , AgriculturaRESUMEN
Hexaploid triticale is an important genetic resource for genetic improvement of common wheat, which can broaden the genetic basis of wheat. In order to lay a foundation for the subsequent research and utilization of triticale germplasm materials, the chromosomal genetic characteristics of cross and backcross offspring of hexaploid triticale×hexaploid wheat were investigated in the process of transferring rye chromatin from hexaploid triticale to hexaploid wheat. Hybrid and backcross combinations were prepared with hexaploid triticale 16yin171 as the maternal parent and hexaploid wheat Chuanmai62 as the paternal parent. The chromosomes in root tip cells of F1, BC1F1 and BC1F2 plants were traced and identified non-denaturing florescence in situ hybridization (ND-FISH). The results indicated that the backcross setting rate of hybrid F1 was 2.61%. The transmission frequency of 2R chromosome was the highest in BC1F1 plants while the transmissibility of rye chromosome in BC1F2 plant was 6R>4R>2R, and the 5B-7B wheat translocation in BC1F2 plants showed severe segregation. A total of 24 structural variant chromosomes were observed both in BC1F1 and BC1F2 plants, including chromosome fragments, isochromosomes, translocations, and dicentric chromosomes. In addition, the seed length and 1000-grain weight of some BC1F2 plants were better than that of the hexaploid wheat parent Chuanmai 62. Therefore, multiple backcrosses should be adopted as far as possible to make the rapid recovery of group D chromosomes, ensuring the recovery of fertility in offspring, when hexaploid tritriale is used as a bridge to introduce rye genetic material into common wheat. At the same time, the potential application value of chromosomal structural variation materials should be also concerned.
Asunto(s)
Triticale , Triticum , Triticum/genética , Triticale/genética , Secale/genética , Cromosomas de las Plantas/genética , Hibridación in Situ , Translocación GenéticaRESUMEN
This study aims to investigate the mechanism of Mailuo Shutong Pills(MLST) on posterior limb muscle swelling caused by femoral fracture(SCFF) through network pharmacology and animal experiments. The plasma components of MLST were analyzed by LC-MS, and the target and signal pathway of SCFF were predicted by network pharmacology and verified by molecular docking. SCFF model rats were established through animal experiments, and different doses of MLST were administered to detect the degree of limb swelling. Hematoxylin-eosin(HE) staining was used to observe pathological changes in muscle tissue, and interleukin-6(IL-6), interleukin-1ß(interleukin-1ß), and tumor necrosis factor-α(TNF-α) in peripheral blood were determined by enzyme-linked immunosorbent assay(ELISA). The expression of relevant signaling pathways was measured by Western blot. Network pharmacological results showed that MLST and SCFF had a total of 153 disease targets, and the key targets were IL-6, TNF, etc., involving mitogen-activated protein kinase(MAPK) signaling pathway, phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT) signaling pathway, etc. The binding energies of the main components and key targets were lower than-7.0 kcal·mol~(-1), indicating that the network analysis results were reliable. The results of animal experiments showed that MLST could reduce the swelling degree and pathological damage of the posterior limb muscles of SCFF rats compared with the model group. ELISA results showed that MLST could reduce the levels of IL-6, IL-1ß, and TNF-α in the serum of SCFF rats. Western blot results showed that MLST can reduce the expression of p-AKT, p-PI3K, p-NF-κB, p-p38 MAPK, and p-ERK in SCFF rats. MLST may reduce the content of inflammatory factors in serum by regulating the expression of PI3K/AKT and MAPK-related signaling pathway protein and improving posterior limb muscle SCFF in rats.
Asunto(s)
Medicamentos Herbarios Chinos , Fracturas del Fémur , Farmacología en Red , Animales , Ratas , Medicamentos Herbarios Chinos/administración & dosificación , Medicamentos Herbarios Chinos/farmacología , Masculino , Fracturas del Fémur/tratamiento farmacológico , Fracturas del Fémur/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Factor de Necrosis Tumoral alfa/genética , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos , Simulación del Acoplamiento Molecular , Interleucina-6/genética , Interleucina-6/metabolismo , Interleucina-1beta/metabolismo , Interleucina-1beta/genética , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Humanos , Fosfatidilinositol 3-Quinasas/metabolismo , Fosfatidilinositol 3-Quinasas/genéticaRESUMEN
A one-pot metal-free protocol to access indazoles from easily available 2-aminophenones and hydroxylamine derivatives has been achieved. The reaction is operationally simple, mild, and insensitive to air and moisture. A broad range of indazoles were prepared in good to excellent yield (up to 97% yield), and the reaction displayed a broad functional group tolerance. The reaction was performed at gram scale, and its synthetic application was exhibited through the rapid and efficient preparation of bioactive molecule YC-3 and FDA-approved drug axitinib.
RESUMEN
Deep insights into and substantial enhancement of the effective anisotropy energy barrier for magnetization reversal (Ueff) are vitally important for the technological applications of dysprosium(III)-based single-molecule magnets (Dy-SMMs). To fully refine the ligand-field effect on spin relaxation, four centrosymmetric {Dy2} entities with formula [Dy2(CH3OH)2L2(RCOO)2] (H2L = 2-hydroxy-N'-((pyridin-2-yl)methylene)benzohydrazide) have been solvothermally prepared by varying the side groups of carboxylate coligands (RCOO-, R = CF3 for 1, H for 2, CH3 for 3, and Cp2Fe for 4). Structural analyses reveal that all of the DyIII carriers in 1-4 have the same N2O6 donor environments, and the non-coordinative R groups attached to the equatorial carboxylate bridges have not substantially changed the binding ability of the shortest Dy-Ophenolate bonds located at the axial position of the ligand field. Interestingly, the side groups have monotonically decreased the zero-field Ueff barriers of these weak antiferromagnetically coupled {Dy2} analogues from 721 K down to 379 K. Further electronic structure calculations demonstrate that the main magnetic axes of 1-4 are highly dominated by these comparable Dy-Ophenolate short bonds, and the g tensors have produced gradually increased transverse components responsible significantly for the decreased Ueff barriers. Additionally, thermally assisted relaxations occur preferably through the second (for 1) and the first (for 2-4) Kramer doublets. These interesting findings afford a new side-group effect to comprehensively understand the magnetostructural relationships and advance the rational design of high-performance Dy-SMMs.
RESUMEN
In recent decades, nanomaterial-based artificial enzymes called nanozymes have received more and more attention and have been applied in biological, chemical, medical, and other fields. In this work, bimetallic FeMn@C was synthesized by calcination from the Prussian blue analogue. The synthesized bimetallic FeMn@C exhibits efficient peroxidase-like activity. The effect of Mn doping amount, catalytic kinetics, and mechanism of FeMn@C nanozyme was further studied in detail. The results show that the peroxidase-like activity of bimetallic FeMn@C is nearly 16 times higher than that of single-metal Fe@C. The peroxidase-like activity of FeMn@C originates from its production of radicals. Compared with natural enzymes, FeMn@C nanozyme has a better affinity for the substrates. Besides, FeMn@C nanozyme has better stability than natural enzymes. Because of its strong magnetism, FeMn@C nanozyme can be recycled easily and exhibits excellent recycling performance. Based on the good affinity of FeMn@C for H2O2, a rapid and selective colorimetric assay for glucose detection is constructed, with a wide linear range of 0.01-0.75 mM and low detection limit of 4.28 µM. This sensor has been successfully applied to the determination of glucose in fruit juice, showing good selectivity and accuracy. The synthesis of bimetallic FeMn@C provides a feasible way to design nanozymes with excellent catalytic activity, high stability, and easy separation.
Asunto(s)
Colorimetría , Peróxido de Hidrógeno , Colorimetría/métodos , Ferrocianuros , Glucosa , PeroxidasasRESUMEN
The electrocatalytic oxygen evolution reaction (OER) is necessary and challenging for converting renewable electricity into clean fuels, because of its complex proton coupled multielectron transfer process. Herein, we investigated the crystal plane effects of NiO on the electrocatalytic OER activity through combining experimental studies and theoretical calculations. The experimental results reveal that NiO nanobelts with exposed {110} crystal planes show much higher OER activity than NiO nanoplates with exposed {111} planes. The efficient OER activity of the {110} crystal planes comes from their intrinsically high catalytic ability and fast charge transfer kinetics. Density functional theory (DFT) shows that the {110} crystal planes possess a lower theoretical overpotential value for the OER, leading to a high electrocatalytic performance. This research broadens our vision to design efficient OER electrocatalysts by the selective exposure of specific crystal planes.
RESUMEN
OBJECTIVE: To compare the intraoperative safety profiles of transurethral plasmakinetic resection of the prostate (PK-TURP) with transurethral plasmakinetic endoscopic enucleation of the prostate (PK-EEP) in the treatment of benign prostatic hyperplasia (BPH) based on endoscopic surgical monitoring system (ESMS). METHODS: A total of 128 patients who were diagnosed with BPH were stratified based on prostate volume (PV) and accepted PK-EEP or PK-TURP treatment at 1:1 ratio. The ESMS as a novel method was used to monitor blood loss and fluid absorption during the operation. Clinical parameters such as intraoperative blood loss volume, fluid absorption volume, operation time, tissue weight of resection, preoperative and postoperative red blood cell count (RBC), hemoglobin concentration (HB), hematocrit (HCT), electrolyte, postoperative bladder irrigation time, indwelling catheter time, hospital stay time and other associated complications were documented and compared between two groups. RESULTS: No significant differences in majority of baseline characteristics were observed among patients with different prostate volumes between two surgical methods. For patients with prostate volume < 40 ml, the average operation time of patients who received PK-EEP treatment was much more than those who received PK-TURP (P = 0.003). On the other hand, for patients with prostate volume > 40 ml, the PK-TURP surgery was associated with a significant increase in intraoperative blood loss (P = 0.021, in PV 40-80 ml group; P = 0.014, in PV > 80 ml group), fluid absorption (P = 0.011, in PV 40-80 ml group; P = 0.006, in PV > 80 ml group) and postoperative bladder irrigation time as well as indwelling catheter time but decrease in resected tissue weight compared to the PK-EEP treatment. CONCLUSION: The ESMS plays an important role in comparison of intraoperative safety profiles between PK-TURP and PK-EEP. Our data suggest that PK-TURP treatment is associated with a decreased operation time in patients with prostate volume < 40 ml and the PK-EEP treatment is associated with decreased intraoperative blood loss, fluid absorption and increased tissue resection for patients with prostate volume > 40 ml. Our results indicate that the size of prostate should be considered when choosing the right operation method.
Asunto(s)
Hiperplasia Prostática , Resección Transuretral de la Próstata , Pérdida de Sangre Quirúrgica , Humanos , Masculino , Hiperplasia Prostática/cirugía , Calidad de Vida , Resección Transuretral de la Próstata/métodos , Resultado del TratamientoRESUMEN
Amanita poisoning is one of the most deadly types of mushroom poisoning. α-Amanitin is the main lethal toxin in amanita, and the human-lethal dose is about 0.1 mg/kg. Most of the commonly used detection techniques for α-amanitin require expensive instruments. In this study, the α-amanitin aptamer was selected as the research object, and the stem-loop structure of the original aptamer was not damaged by truncating the redundant bases, in order to improve the affinity and specificity of the aptamer. The specificity and affinity of the truncated aptamers were determined using isothermal titration calorimetry (ITC) and gold nanoparticles (AuNPs), and the affinity and specificity of the aptamers decreased after truncation. Therefore, the original aptamer was selected to establish a simple and specific magnetic bead-based enzyme linked immunoassay (MELISA) method for α-amanitin. The detection limit was 0.369 µg/mL, while, in mushroom it was 0.372 µg/mL and in urine 0.337 µg/mL. Recovery studies were performed by spiking urine and mushroom samples with α-amanitin, and these confirmed the desirable accuracy and practical applicability of our method. The α-amanitin and aptamer recognition sites and binding pockets were investigated in an in vitro molecular docking environment, and the main binding bases of both were T3, G4, C5, T6, T7, C67, and A68. This study truncated the α-amanitin aptamer and proposes a method of detecting α-amanitin.
Asunto(s)
Agaricales/química , Alfa-Amanitina/análisis , Alfa-Amanitina/orina , Aptámeros de Nucleótidos/química , Ensayo de Inmunoadsorción Enzimática/métodos , Alfa-Amanitina/química , Alfa-Amanitina/metabolismo , Aptámeros de Nucleótidos/metabolismo , Colorimetría/métodos , Oro , Humanos , Fenómenos Magnéticos , Nanopartículas del Metal , Simulación del Acoplamiento Molecular , Intoxicación por Setas/diagnóstico , Intoxicación por Setas/orina , Sensibilidad y EspecificidadRESUMEN
White-rot fungi, especially Trametes strains, are the primary source of industrial laccases in bioenergy and bioremediation. Trametes strains express members of the laccase gene family with different physicochemical properties and expression patterns. However, the literature on the expression pattern of the laccase gene family in T. trogii S0301 and the response mechanism to Cu2+, a key laccase inducer, in white-rot fungal strains is scarce. In the present study, we found that Cu2+ could induce the mRNAs and proteins of the two alternative splicing variants of heat shock transcription factor 2 (TtHSF2). Furthermore, the overexpression of alternative splicing variants TtHSF2α and TtHSF2ß-I in the homokaryotic T. trogii S0301 strain showed opposite effects on the extracellular total laccase activity, with the maximum laccase activity of approximately 0.6 U mL-1 and 3.0 U mL-1, respectively, on the eighth day, which is 0.4 and 2.3 times that of the wild type strain. Similarly, TtHSF2α and TtHSF2ß-I play opposite roles in the oxidation tolerance to H2O2 In addition, the direct binding of TtHSF2α to the promoter regions of the representative laccase isoenzymes (TtLac1 and TtLac13) and protein-protein interactions between TtHSF2α and TtHSF2ß-I were detected. Our results demonstrate the crucial roles of TtHSF2 and its alternative splicing variants in response to Cu2+ We believe that these findings will deepen our understanding of alternative splicing of HSFs and their regulatory mechanism of the laccase gene family in white-rot fungi.Importance The members of laccase gene family in Trametes strains are the primary source of industrial laccase and have gained widespread attention. Increasing the yield and enzymatic properties of laccase through various methods has always been a topic worthy of attention, and there is no report on the regulation of laccase expression through HSF transcription factor engineering. Here, we found that two alternative splicing variants of TtHSF2 functioned oppositely in regulating the expression of laccase genes, and copper can induce the expression of almost all members of the laccase gene family. Most importantly, our study suggested that TtHSF2 and its alternative splicing variants are vital for copper-induced production of laccases in T. trogii S0301.
RESUMEN
In the present study, we found that tryptophan (TRP) and tyrosine (TYR) levels are increased in hemolymph of male Nauphoeta cinerea after social contact with either male or female conspecifics. Hemolymph was collected from individual males before and after the social interactions, and samples were analyzed by HPLC-ECD; analyte identities were confirmed by UPLC/MS. After a male-male first encounter fight, hemolymph TRP and TYR levels were significantly increased in dominants compared with the levels before the encounter. Conversely, TRP and TYR in subordinates were maintained at levels similar to those before the encounter. While after-fight TRP and TYR levels were significantly higher in dominants than subordinates, no significant differences were found in the contestants before the fight. Moreover, contact with an isolated male antenna was sufficient to stimulate attack behavior and increase hemolymph TRP and TYR titers to levels similar to those seen in dominants. After a male-female interaction, two distinct outcomes could be observed. Either hemolymph TRP and TYR levels were increased in successfully mated males, or TRP and TYR levels were unchanged in males that only exhibited premating wing-raising behavior but failed in mating. After contacting the antenna of a socially naïve male with an isolated female antenna, three patterns of behavior and related amino acid response were observed: 1) only premating wing-raising behavior with significant increase of TRP and TYR levels, 2) only attack behavior with significant increase of TRP and TYR levels, and 3) mixed wing-raising and attack behaviors with no significant changes in TRP and TYR levels. The present results show a robust response of hemolymph TRP and TYR to social contact. In light of previously characterized responses in pheromone and juvenile hormone levels, these amine responses suggest that the physiological response of N. cinerea to social contact is multi-dimensional.
Asunto(s)
Cucarachas , Hemolinfa/metabolismo , Tirosina/metabolismo , Animales , Masculino , Interacción Social , TriptófanoRESUMEN
Microencapsulated phase-change material (ME-PCM) employing octadecane as a core material has been practiced for thermal-energy-storage (TES) applications in buildings. However, octadecane as a hydrocarbon-based PCM is flammable. Herein, silica-shelled microcapsules (SiO2-MCs) and poly(urea-formaldehyde)-shelled microcapsules (PUF-MCs) were successfully prepared, loaded with octadecane/tributyl phosphate (TBP) as hybrid core materials, which not only exhibited good TES properties but also high-effective flame retardancy. SiO2-MC (ΔHm = 124.6 J g-1 and ΔHc = 124.1 J g-1) showed weaker TES capacity than PUF-MC (ΔHm = 186.8 J g-1, ΔHc = 188.5 J g-1) but better flame retardancy with a lower peak heat-release rate (HRRpeak) of 460.9 W g-1 (556.9 W g-1 for PUF-MCs). As compared with octadecane (38.7 kJ g-1), the reduction in total heat release (THR) for SiO2-MC was up to 22% (30.1 kJ g-1) with combustion time shortened by 1/6. SiO2-MC had a typical diameter of 150-210 µm, shell thickness of â¼6.5 µm, and a core fraction of 84 wt %. SiO2-MC showed better thermal stability with a higher initial evaporation/pyrolysis temperature than PUF-MC. The thermal decomposition of MCs with its mechanism of flame retardancy was significantly studied using thermogravimetric analysis/infrared spectrometry (TG-IR). The strategy presented in this study should inspire the development of microcapsules with PCMs/flame retardants as hybrid core materials for structural applications.
RESUMEN
Anticipatory behaviour is the expectation of a near-future event based on information processed in the past and influences an animal's tactical decisions, particularly when there are significant fitness consequences. The grass lizard (Takydromus viridipunctatus) perches on blades of grass at night which likely reduces the probability of predation by terrestrial predators such as snakes, rodents and shrews. During twilight (starting 30 min before sunrise), they move from above the grass to within grass clumps and this is thought to afford the lizard protection while reducing detection by avian predators. Here, we examined how lizards shift their behaviour as a function of visual detectability to their primary predator, the cattle egret (Bubulcus ibis). We show that the lizards shift from their perch site during twilight at the earliest time at which egrets depart communal roosts. At the same time, visual modelling shows a dramatic increase in the detectability of the lizards to the visual system of egrets. Therefore, anticipatory behaviour in response to environmental cues acts to reduce predation risk as lizards become more conspicuous and predators become more active. Grass lizard anticipatory behaviour appears to be finely tuned by natural selection to adjust to temporal changes in predation risk.
Asunto(s)
Lagartos , Percas , Animales , Aves , Bovinos , Conducta Predatoria , SerpientesRESUMEN
One mononuclear complex [Dy(Htpy)(NO3)2(acac)] (1) and a tpy--extended 1D chain {[Dy(CH3OH)(NO3)2(tpy)]·CH3OH}n (2) (Htpy = 4'-(4-hydroxyphenyl)-2,2':6',2''-terpyridine, Hacac = acetylacetone) were successfully designed to investigate the effect of bond length tuning around the DyIII cation on the magnetic dynamics of single-molecule magnets (SMMs). Interestingly, two magnetic entities possess the same local coordination sphere (N3O6-donor) as well as the configuration (Muffin, Cs) of dysprosium centers. Only a slight difference in structure results from purposefully substituting the acetylacetone ligand in 1 with hydroxyl oxygen from tpy- linkage and one methanol molecule in 2. However, the remarkable differences in dynamics behavior were clearly found between them. Compound 1 possesses a thermal-activated effective energy barrier (Ueff/kB) of 22.7 K under a 0 kOe direct current (dc) field and negligible hysteresis loop at 2.0 K, while complex 2 shows high-performance SMM behavior with the largest energy barrier of 354.36 K among the reported nine-coordinated DyIII-based systems and the magnetic hysteresis up to 4.0 K at a sweep rate of 200 Oe s-1. These experimental results combined with the previous reported data reveal that the shortest bond and the bond length difference around the DyIII center synergistically determine the dynamics of SMMs. The uniaxial anisotropy increases with the decrease of the shortest bond and the increase of the bond length difference, which is confirmed by the theoretical calculations.
RESUMEN
Three isostructural pillared-layer frameworks with M-BDC-X layers supported by ditopic HL connectors, [M(HL)(BDC)0.5X] n (HL = 4'-(4-hydroxyphenyl)-4,2':6',4â³-terpyridine, BDC = terephthalate, M = Cd, X = Cl for (1), M = Cd, X = formate for (2), and M = Co, X = formate for (3)), were solvothermally synthesized, and used as photocatalysts for Pt-assisted visible-light-initiated hydrogen evolution from water splitting. These water-durable frameworks exhibit varied hydrogen production rates of 361.2, 271.3, and 327.5 µmol · g-1 · h-1 in 12 h due to their slightly different donor environments of the octahedral CdII and CoII ions. Further experimental and theoretical investigations reveal that the metal ions and the local coordination surroundings have essentially dominated the conduction band minimum and electric resistance of the charge transport, which play highly important roles for the improved catalytic hydrogen evolution ability. These findings demonstrate the electronic effect of the slightly ligand field modifications on the boosting hydrogen generation activity in the noble metal-assisted MOF photocatalytic systems.
RESUMEN
The population loss rate of a honey bee colony is a critical index to verify its health condition. Forecasting models for the population loss rate of a honey bee colony can be an essential tool in honey bee health management and pave a way to early warning methods in the understanding of potential abnormalities affecting a honey bee colony. This work presents a forecasting and early warning algorithm for the population daily loss rate of honey bee colonies and determining warning levels based on the predictions. Honey bee colony population daily loss rate data were obtained through embedded image systems to automatically monitor in real-time the in-and-out activity of honey bees at hive entrances. A forecasting model was trained based on temporal convolutional neural networks (TCN) to predict the following day's population loss rate. The forecasting model was optimized by conducting feature importance analysis, feature selection, and hyperparameter optimization. A warning level determination method using an isolation forest algorithm was applied to classify the population daily loss rate as normal or abnormal. The integrated algorithm was tested on two population loss rate datasets collected from multiple honey bee colonies in a honey bee farm. The test results show that the forecasting model can achieve a weighted mean average percentage error (WMAPE) of 17.1 ± 1.6%, while the warning level determination method reached 90.0 ± 8.5% accuracy. The forecasting model developed through this study can be used to facilitate efficient management of honey bee colonies and prevent colony collapse.