Complex Formation Research Articles

The chlorite adduct of aquacobalamin: contrast with chlorite dismutase.

In the reaction of aquacobalamin (aquaCbl) with chlorite, a stable species is detected and assigned as a Co(III)-chlorite complex, Co(III)-OClO-. Its UV-Vis spectrum is almost identical to that of aquaCbl, except for some minor differences at ~ 430nm; cyanide can eliminate and prevent these changes. The 1H-NMR spectra reveal strong influences of chlorite on the B2 and B4 protons of the cobalt-bound dimethyl benzimidazole ligand. Together, the UV-Vis and NMR titrations suggest a Kd of 10mM or higher for chlorite on Cbl. Resonance Raman spectra reveal minor changes in the spectrum of aquaCbl to chlorite-as well as a disappearance of the free chlorite signals, consistent with Cbl-chlorite complex formation. Corroboration for these interpretations is also offered from mass spectrometry and DFT calculations. This Co(III)-OClO- complex would be a stable analogue of the first reaction intermediate in the catalytic cycle of chlorite dismutase, or in the reaction of chlorite with a number of other heme proteins. The differences in reactivity between Co(III) cobalamin and Fe(III) heme towards chlorite are analyzed and rationalized, leading to a reconciliation of experimental and computational data for the latter.

Elevated reactive oxygen species can drive the alternative lengthening of telomeres pathway in ATRX-null cancers.

The alternative lengthening of telomeres (ALT) pathway is a telomerase-independent mechanism for immortalization in cancer cells and is commonly activated in low-grade and high-grade glioma, as well as osteosarcoma. The ALT pathway can be activated under various conditions and has often been shown to include mutational loss of ATRX. However, this is insufficient in isolation and so other cellular event must also be implicated. It has been shown that excessive accumulation of DNA:RNA hybrid structures (R-loops) and/or formation of DNA-protein crosslinks (DPCs) can be other important driving factors. The underlying cellular events leading to R-loop and DPC formation in ALT cancer cells to date remain unclear. Here, we demonstrate that excessive cellular reactive oxygen species (ROS) is an important causative factor in the evolution of ALT-telomere maintenance in ATRX-deficient glioma. We identified three sources of elevated ROS in ALT-positive gliomas: co-mutation of SETD2, downregulation of DRG2, and hypoxic tumour microenvironment. We demonstrate that elevated ROS leads to accumulation of R-loops and, crucially, resolution of R-loops by the enzyme RNase H1 prevents ALTpathway activity in cells exposed to elevated ROS. Further, we found a possible causal link between the formation of R-loops and the accumulation of DPCs, in particular, formation of TOP1 complexes covalently linked to DNA (Top1cc). We also demonstrate that elevation of ROS can trigger over-activity of the ALT pathway in osteosarcoma and glioma cell lines, resulting in excessive DNA damage and cell death. This work presents important mechanistic insights into the endogenous origin of excessive R-loops and DPCs in ALT-positive cancers, as well as highlighting potential novel therapeutic approaches in these difficult-to-treat cancer types.

Effect of molecular structure on the thermodynamic behaviour of binary mixture at various temperatures: correlation with the Jouyban–Acree model (2-nitroanisole with 2,6-dimethylcyclohexanone, 2-methylcyclohexanone and cyclohexanone)

ABSTRACT Excessmolar volume, excess isentropic compressibility, deviation inviscosity, and excess Gibbs free energy for activation of viscous flow were determined for binary mixtures of 2-nitroanisole with substituted cyclohexanone (2,6-dimethylcyclohexanone (J1), 2-methylcyclohexanone (J2), and cyclohexanone (J3)) at selected compositions and temperatures ranging from 303.15 K to 313.15 K. These properties were calculated from experimentally measured densities, viscosities, and speeds of sound. The results were analysed in terms of intermolecular interactions, specifically dipole-dipole interactions leading to charge complex formation. The Jouyban-Acre e model was used to correlate the experimental density and speed of sound data, with the accuracy assessed using mean relative deviation (MRD) and individual relative deviation (IRD).

Do wolframin, P-glycoprotein, and GRP78/BiP cooperate to alter the response of L1210 cells to endoplasmic reticulum stress or drug sensitivity?

In previous research, we revealed that murine leukemia cells L1210 with induced expression of P-glycoprotein (P-gp, a membrane drug transporter, product of the Abcb1 gene) are better able to withstand endoplasmic reticulum (ER) stress (ERS) than their P-gp negative counterparts. This was associated with increased GRP78/BiP expression and modulation of the expression of several other proteins active in the cellular response to ERS (like CHOP, spliced XBP1, 50-kDa ATF6 protein fragment and others) in P-gp positive cells. Wolframin is an ER transmembrane protein, product of the WFS1 gene whose mutations are associated with Wolfram syndrome. However, this protein is frequently overexpressed in cells undergoing ERS and its expression may accompany changes in the above ERS markers. Therefore, our aim in this work was to investigate wolframin expression in P-gp-negative and P-gp-positive murine leukemia L1210 cells in relation to ERS related proteins in normal or ERS condition. We induced ERS in cells either by blocking N-glycosylation in the ER with tunicamycin or by blocking ER Ca2+-ATPase activity with thapsigargin, as known ER stressors. The results of this paper demonstrated increased wolframin expression in P-gp positive cells compared to P-gp negative cells. Immunoprecipitation experiments revealed the formation of complexes between wolframin and ERS related proteins (PERK, ATF6 and GRP78/BiP), the amount of which varied depending on the presence of the above ER stressors.Graphical

PfFBXO1 is essential for inner membrane complex formation in Plasmodium falciparum during both asexual and transmission stages

Plasmodium species replicate via schizogony, which involves asynchronous nuclear divisions followed by semi-synchronous segmentation and cytokinesis. Successful segmentation requires a double-membranous structure known as the inner membrane complex (IMC). Here we demonstrate that PfFBXO1 (PF3D7_0619700) is critical for both asexual segmentation and gametocyte maturation. In Toxoplasma gondii, the FBXO1 homolog, TgFBXO1, is essential for the development of the daughter cell scaffold and a component of the daughter cell IMC. We demonstrate PfFBXO1 forming a similar IMC initiation scaffold near the apical region of developing merozoites and unilaterally positioned in gametocytes of P. falciparum. While PfFBXO1 initially localizes to the apical region of dividing parasites, it displays an IMC-like localization as segmentation progresses. Similarly, PfFBXO1 localizes to the IMC region in gametocytes. Following inducible knockout of PfFBXO1, parasites undergo abnormal segmentation and karyokinesis, generating inviable daughters. PfFBXO1-deficient gametocytes are abnormally shaped and fail to fully mature. Proteomic analysis identified PfSKP1 as one of PfBXO1’s stable interacting partners, while other major proteins included multiple IMC pellicle and membrane proteins. We hypothesize that PfFBXO1 is necessary for IMC biogenesis, chromosomal maintenance, vesicular transport, and ubiquitin-mediated translational regulation of proteins in both sexual and asexual stages of P. falciparum.

Antifungal activity and biocompatibility assessment with molecular docking and dynamic simulations of new pyrazole derivatives

BackgroundBecause of their many bioactivities, which include psychoanalytic, antifungal, antihypertensive, anti-inflammatory, and antiviral properties, pyrazoles and their derivatives are attracting interest in pharmacology and medicine, the pressing need for novel fungicides is increased for lessened by the growing microbiological resistance of illnesses to recognized antibiotics.ObjectiveThe current work validates the results and pyrazole binding sites as potent antifungals by investigating many pyrazole derivatives as antifungal agents. The biocompatibility was assessed using an HFB4 normal human skin cell line.MethodsThe biocompatibility was evaluated using an HFB4 normal human skin cell line and the findings of pyrazole binding sites were confirmed using molecular docking. The antifungal investigation was against 4 fungal pathogens: Aspergillus flavus ATCC 9643, A. niger ATCC 11414, Rhizopus oryzae ATCC 96382, and Penicillium chrysogenum ATCC 10106.ResultsAmong 20 different Pyrazole derivatives, Pyrazole 3b is the most effective compound against A. niger ATCC 11414 and A. flavus ATCC 9643 with IZDs and AIs of 32.0 mm (1.10) and 30.0 mm (1.0), respectively. Followed by compound 10b scored 28 and 20 mm for A. niger and P. chrysogenum ATCC 10106, respectively. While R. oryzae ATCC 96382 exhibited resistance with all pyrazole compounds. The study found that pyrazole 3b showed 100% antifungal activity between 1000 and 500 μg/ml, 50% at doses of 250 μg/ml, and no antifungal action at a dose of 125 μg/ml against the studied pathogenic fungal strains. The biocompatibility investigation showed that the 3b compound was completely safe with no IC50 dose obtained. The effectiveness of several pyrazole compounds against fungal targets was confirmed through molecular docking studies. The results highlighted that compounds 3b, 3g, 3h, 10b, 7, and 12 displayed strong binding energies, effectively engaging with the active sites of key proteins in various fungi such as FDC1 in A. niger, uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) in A. flavus, and Adenosine 5′-phosphosulfate kinase in P. chrysogenum. These interactions encompassed diverse molecular bonding types, suggesting these compounds’ potential to hinder enzyme activity and demonstrate notable antifungal properties. Additionally, the computational ADMET “Absorption–distribution–metabolism–excretion–toxicity” analysis of these compounds revealed adherence to Lipinski’s rules, indicating favorable physicochemical characteristics. The molecular dynamic simulations of Adenosine 5’-phosphosulfate kinase in P. chrysogenum, UDP-N-acetylglucosamine in A. flavus, and FDC1 in A. niger with 10b also demonstrated the formation of stable complexes with favorable values of Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF), Solvent Accessible Surface Area (SASA), and Radius of Gyration (Rg). These findings support the compounds’ potential in ongoing therapeutic development projects.ConclusionThe study found that pyrazole 3b was the most effective antifungal agent. The compounds’ strong binding energies with fungi proteins suggest potential drug development.

Bi-allelic KICS2 mutations impair KICSTOR complex-mediated mTORC1 regulation, causing intellectual disability and epilepsy.

Nutrient-dependent mTORC1 regulation upon amino acid deprivation is mediated by the KICSTOR complex, comprising SZT2, KPTN, ITFG2, and KICS2, recruiting GATOR1 to lysosomes. Previously, pathogenic SZT2 and KPTN variants have been associated with autosomal recessive intellectual disability and epileptic encephalopathy. We identified bi-allelic KICS2 variants in eleven affected individuals presenting with intellectual disability and epilepsy. These variants partly affected KICS2 stability, compromised KICSTOR complex formation, and demonstrated a deleterious impact on nutrient-dependent mTORC1 regulation of 4EBP1 and S6K. Phosphoproteome analyses extended these findings to show that KICS2 variants changed the mTORC1 proteome, affecting proteins that function in translation, splicing, and ciliogenesis. Depletion of Kics2 in zebrafish resulted in ciliary dysfunction consistent with a role of mTORC1 in cilia biology. These invitro and invivo functional studies confirmed the pathogenicity of identified KICS2 variants. Our genetic and experimental data provide evidence that variants in KICS2 are a factor involved in intellectual disability due to its dysfunction impacting mTORC1 regulation and cilia biology.

Pair correlation microscopy of intracellular molecular transport.

Pair correlation microscopy is a unique approach to fluorescence correlation spectroscopy that can track the long-range diffusive route of a population of fluorescent molecules in live cells with respect to intracellular architecture. This method is based on the use of a pair correlation function (pCF) that, through spatiotemporal comparison of fluctuations in fluorescence intensity recorded throughout a microscope data acquisition, enables changes in a molecule's arrival time to be spatially mapped and statistically quantified. In this protocol, we present guidelines for the measurement and analysis of line scan pair correlation microscopy data acquired on a confocal laser scanning microscope (CLSM), which will enable users to extract a fluorescent molecule's transport pattern throughout a living cell, and then quantify the molecular accessibility of intracellular barriers encountered or the mode of diffusion governing a molecular trafficking event. Finally, we demonstrate how this protocol can be extended to a two-channel line scan acquisition that, when coupled with a cross pCF calculation, enables a fluorescent molecule's transport pattern to be selectively tracked as a function of complex formation with a spectrally distinct fluorescent ligand. For a skilled user of a CLSM, the line scan data acquisition and analysis described in this protocol will take ~1-2 d, depending on the sample and the number of experiments to be processed.

Enhanced Intracellular Protein Activity by Caveolae-Mediated Endocytosis of Conjugated Polymer/Protein Complexes.

Conjugated polymers (CPs) with rigid hydrophobic backbones and polar side chains are known for their efficient cellular entry using various endocytic pathways. Here, the efficient delivery of ribonuclease A (RNase A) into the cytosol of a model cancer cell using a charge-neutral CP with phenyl carbamoylated guanidine (Ph-CG) group at the end of a short ethylene oxide side chain is described. This unique combination of the hydrophobic backbone and the polar nonionic side chain facilitates efficient protein complex formation and subsequent cellular entry through a non-lysosomal pathway, leading to concentration-dependent cell viability inhibition at a half-maximal effective concentration of 0.07µgmL-1 (or 5nm). This work demonstrates the potential of CPs as carriers for intracellular protein delivery and the importance of the end functional group of protein carriers.

Complex formation between n-alkyltrimethylammonium bromides and water-soluble calix[n]arenes

Abstract Complex formation between n-alkyltrimethylammonium bromides and water-soluble calix[n]arenes (n = 4, 6, 8) (CALXSn) was studied by potentiometric titration and molecular dynamic simulation. The binding isotherms were found to be composed of two phases; the first phase is strong specific binding to a few sites and the second phase is cooperative binding to the residual sites. Binding constant for the first specific binding was found to increase with an increase in the number of ring members of CALXSn. Binding constants for CALXS4 and CALXS6 systems did not change significantly with the length of the surfactant's alkyl chain and with the pH change from 7.0 to 12.5, while that for CALXS8 systems tended to increase with an increase in the alkyl-chain length. The specific binding disappeared with the pH increase. The thermodynamic parameters showed an enthalpy-entropy compensation relation with a compensation temperature of 289 K. The second phase was observed mainly for n-dodecyltrimethylammonium-CALXSn systems. The cooperativity parameter was found to increase with an increase in the number of ring member of CALXSn and is attributed to the contribution of increasing conformational flexibility of CALXSn as the number of ring members increases. MD simulation on CALXSn with and without n-alkyltrimethylammonium ion provided structural interpretation for the features of binding data.

Reactivity of Methyl Diruthenium Complexes with the Bis(diphenylphosphino)methane (dppm) Ligand and Formation of Dinitrogen and Dihydrogen Complexes via Methane Loss

Reactivity of Methyl Diruthenium Complexes with the Bis(diphenylphosphino)methane (dppm) Ligand and Formation of Dinitrogen and Dihydrogen Complexes via Methane Loss

Lanthanide Molecular Clusters and Metal-Organic Layers Constructed by Manipulation of Substituents.

Usually, complexes with different connections and shapes are constructed by regulating the substituents. However, it is extremely challenging to construct two lanthanide complexes with different dimensions by only fine-tuning the substituents of the ligands, especially the substituents (-CH3 and -CH2CH3) with almost similar physical and chemical properties. Herein, by only regulating the substituents of the multidentate chelating ligands, two lanthanide complexes with different dimensions and connection modes were successfully constructed using a multicomponent "one-pot method" under the guidance of the multidentate chelating coordination method (MCC). They are the 11-nuclear lanthanide molecular cluster (Dy11) and the metal-organic layer (2D-Dy). Specifically, when the selected ligand is an imidazole-2-carboxaldehyde derivative and its substituent is -CH3, a layered 2D-Dy is obtained. The linker [Dy(HL1)3] with a propeller configuration is formed by chelating the Dy(III) ion with an acylhydrazone ligand (HL1) formed by the condensation of three salicylhydrazides and 1-methyl-1H-imidazole-2-carboxaldehyde. The above linkers were further linked alternately with propeller-shaped [Dy(NO3)3] as a secondary building unit (SBU) to form 2D-Dy. In addition, by changing the -CH3 on the ligand to -CH2CH3, we obtained an example of Dy11 formed by epitaxial assembly of two Dy(III) ions with an hourglass-shaped Dy9 as the core, and its molecular formula is [Dy11(HL2)8(μ3-OH)8(μ4-O)2(CH3O)4(NO3)4](NO3)5 18CH3OH. The cluster Dy11 was bombarded using high-resolution electrospray ionization mass spectrometry (HRESI-MS) and the molecular ion peaks of various fragments formed were captured. Based on the above molecular ion peaks, the possible fragmentation mechanisms of Dy11 were inferred to be Dy11 → Dy4(HL2)4 → Dy3(HL2)2 → Dy2(HL2)2 → Dy(HL2)2 and Dy11 → Dy(HL2)2/Dy2(HL2)2/Dy3(HL2)2/Dy4(HL2)4. This work is one of the rare examples where fine-tuning of ligand substituents leads to the formation of complexes of different dimensions, which promotes the progress of crystal engineering of lanthanide complexes.

COCOMO2: A Coarse-Grained Model for Interacting Folded and Disordered Proteins.

Biomolecular interactions are essential in many biological processes, including complex formation and phase separation processes. Coarse-grained computational models are especially valuable for studying such processes via simulation. Here, we present COCOMO2, an updated residue-based coarse-grained model that extends its applicability from intrinsically disordered peptides to folded proteins. This is accomplished with the introduction of a surface exposure scaling factor, which adjusts interaction strengths based on solvent accessibility, to enable the more realistic modeling of interactions involving folded domains without additional computational costs. COCOMO2 was parametrized directly with solubility and phase separation data to improve its performance on predicting concentration-dependent phase separation for a broader range of biomolecular systems compared to the original version. COCOMO2 enables new applications including the study of condensates that involve IDPs together with folded domains and the study of complex assembly processes. COCOMO2 also provides an expanded foundation for the development of multiscale approaches for modeling biomolecular interactions that span from residue-level to atomistic resolution.

Visible Light Boosted the Reduction of Cr(VI) in the Absence of Conventional Reductants in Frozen Solutions: The Overlooked Role of Inorganic Anions.

The conversion of Cr(VI) in frozen solutions is a mysterious process in the water environment. It has traditionally been believed that the reduction of Cr(VI) can only occur through interaction with traditional reducing agents like natural organic matters (NOMs) and Fe(II), with H2O merely acting as a solvent. However, this study reveals that visible light can induce the reduction of Cr(VI) by H2O even without conventional reducing agents. Specifically, within the narrow liquid-like layer between ice crystals, there is a significant increase in concentrations of protons, Cr(VI), and anions (Cl-, SO42-, and NO3-), which promotes the formation of various complexes between Cr(VI) and anions. DFT results reveal 11 types of stable Cr(VI)-anion complexes in solution, with six exhibiting visible light absorption properties. Quadrupole time-of-flight (QTOF) mass spectrometry confirms that the abundance of these six complexes (Cl-CrO2-Cl, Cr2O6-Cl, Cl-Cr2O5-Cl, Cr2O6-OSO3H, HO3SO-Cr2O5-OSO3H, and Cr2O6-ONO2) correlates with the extent to which visible light promotes Cr(VI) reduction, thus highlighting their crucial role as photoreactive intermediate complexes during this conversion process. These findings suggest that H2O in frozen solutions should no longer be regarded solely as a solvent but also as a reactant, thereby inspiring deeper insights into frozen solution chemistry.

Cooperative B-H Activation: Ligand Diversity in Groups 6 and 8 Transition Metal κ2-N,E-Chelated Complexes (E = S or Se).

The synthesis, structure, and reactivity of the N-heterocyclic carbene (NHC)-supported κ2-N,S-chelated ruthenium complex [(IMe)(PPh3)Ru{κ2-N,S-(mbz)}2] (IMe = 1,3-dimethylimidazol-2-ylidene, mbz = 2-mercaptobenzothiazolyl (NC7H4S2)), 2 has been established. Complex 2 is generated from the reaction of [Ru(PPh3)2Cl2], 1 with IMe followed by the addition of [(mbz)K]. The room-temperature reaction of 2 with [BH3·THF] led to the formation of the dihydridoborate complex, [(Ph3P)Ru{κ3-H,S,S'-(NH2BSBH2N)(S2C7H4)2}], 3. Further, the synthesis and structure of Cp*-supported κ2-N,S-chelated tungsten complexes, [Cp*W(CO)2{κ2-N,S-(NC7H4S2)}], 5 and [Cp*W(CO)2{κ2-N,S-(NC7H4S2)}{κ2-N,S-(N(CH3)C5H4S)}], 6, generated from the reaction of [Cp*W(CO)3Me], 4 and [Na(H3B-NC7H4S2)] have been described. In a similar fashion, pyridine-2-thiolato/selenolato ligand-supported Cp*-based κ2-N,E-chelated (E = S and Se) tungsten complexes, [Cp*W(CO)2{κ2-N,E-(NC5H4E)}] (7a: E = S (pyridine-2-thiolato), 7b: E = Se (pyridine-2-selenolato)), have been isolated from the reaction of [Cp*W(CO)3Me], 4 and [Na(H3B-NC5H4E)] ligands. The reaction of bulky borane ArFBH2 (ArF = 3,5-bistrifluoromethylbenzyl) with 5 led to the isolation of a borate species, [Cp*W(CO)2{κ2-S,H-(H2ArFB-NC7H4S2)}], 10. The complex [Cp*Mo(CO)2{κ2-N,Se-(NC5H4Se)}], 9 generated from the salt elimination reaction of [Cp*Mo(CO)3Cl], 8 and [K(NC5H4Se)] reacts with [BH3·THF] to yield the borate complex [Cp*Mo(CO)2{κ2-Se,H-(H3B-NC5H4Se)}], 11. To investigate the effect of the ligand diversities on the reactivity of all of the κ2-N,E-chelated complexes, density functional theory (DFT)-based calculations were performed.

Functional screen identifies RBM42 as a mediator of oncogenic mRNA translation specificity.

Oncogenic protein dosage is tightly regulated to enable cancer formation but how this is regulated by translational control remains unknown. The Myc oncogene is a paradigm of an exquisitely regulated oncogene and a driver of pancreatic ductal adenocarcinoma (PDAC). Here we use a CRISPR interference screen in PDAC cells to identify activators of selective MYC translation. The top hit, the RNA-binding protein RBM42, is highly expressed in PDAC and predicts poor survival. We show that RBM42 binds and selectively regulates the translation of MYC and a precise suite of pro-oncogenic transcripts, including JUN and EGFR. Mechanistically, we find that RBM42 binds and remodels the MYC 5' untranslated region structure, facilitating the formation of the translation pre-initiation complex. Importantly, RBM42 is necessary for PDAC tumorigenesis in a Myc-dependent manner in vivo. This work transforms the understanding of the translational code in cancer and illuminates therapeutic openings to target the expression of oncogenes.

Synthesis of Vinyl Sulfones from Substituted Alkenes via Molybdooxaziridine Catalysis

AbstractHerein we report the MoO2Dipic promoted sulfonation of alkenes using N−Ts‐hydroxylamine as the quantitative source of Ts. The reaction works with high yields and stereoselectivities for styrenes with a wide variety of substitution patterns. A novel atom transfer radical addition mechanism involving the formation of molybdooxaziridine complex 1 as the active catalyst, difunctionalization with Ts‐NO, followed by oxidation, and then elimination as the rate‐determining‐step for the formation of vinylsulfone 3 has been proposed. Initial kinetic and mechanistic data indicates the formation of Ts‐NO and provides evidence for the proposed mechanism.

Automated Investigation of Metal-ligand Interactions by a Newly Established Robotic Workflow for Titrations.

In this work, we present a new workflow to set up an automated platform for the investigation of metal complex formation in solutions. With the utilization of this robot titration platform, the generation of an abundancy of solvated metal complexes in differing coordination number is possible in a simple manner. The generated complexes can subsequently be sampled into differing vessels to examine them in detail. We present sampling for UV/Vis and NMR spectroscopy at chosen model systems, however, the platform can easily be adapted to provide samples for other techniques, e.g., for infrared spectroscopy.

Bonobos point more for ignorant than knowledgeable social partners.

Numerous uniquely human phenomena, from teaching to our most complex forms of cooperation, depend on our ability to tailor our communication to the knowledge and ignorance states of our social partners. Despite four decades of research into the "theory of mind" capacities of nonhuman primates, there remains no evidence that primates can communicate on the basis of their mental state attributions, to enable feats of coordination. Moreover, recent reevaluation of the experimental literature has questioned whether primates can represent others' ignorance at all. The present preregistered study investigated whether bonobos are capable of attributing knowledge or ignorance about the location of a hidden food reward to a cooperative human partner, and utilizing this attribution to modify their communicative behavior in the service of coordination. Bonobos could receive a reward that they had watched being hidden under one of several cups, if their human partner could locate the reward. If bonobos can represent a partner's ignorance and are motivated to communicate based on this mental state attribution, they should point more frequently, and more quickly, to the hidden food's location when their partner is ignorant about that location than when he is knowledgeable. Bonobos indeed flexibly adapted the frequency and speed of their communication to their partner's mental state. These findings suggest that apes can represent (and act on) others' ignorance in some form, strategically and appropriately communicating to effectively coordinate with an ignorant partner and change his behavior.

Exploring the frequency degenerate range of the three-dimensional structured lights in selectively end-pumped Nd:YVO4 laser

Three-dimensional (3D) structured light is a complex form of structured light characterized by ray-wave duality. The principle for generating 3D structured laser transverse modes has been well-established through numerous experiments. However, little research has been focused on the frequency degeneracy range during the process of obtaining these modes. In this work, we utilize a Radio-Frequency (RF) spectrum analyzer to record frequency signal data at different accidental degeneracies. By analyzing the variation of the frequency signal as the resonator length changes, we determined the exact degeneracy range. Near the 1/5 degeneracy cavity, the exact range was found to be from 18.20 mm to 18.10 mm. Near the 1/6 degeneracy cavity, the degenerate cavity length range was determined to be from 12.55 mm to 12.45 mm. This work demonstrates that monitoring the RF signal changes with the analyzer enables precise identification of the resonator’s fine cavity length and degeneracy range, based on ray-wave duality. It also introduces a novel method for evaluating the stability of 3D structured laser transverse modes in the frequency domain.