Spatial Risk Effects From Lions Compound Impacts of Prey Depletion on African Wild Dogs.

Prey depletion threatens many carnivore species across the world and can especially threaten low-density subordinate competitors, particularly if subordinates are limited to low densities by their dominant competitors. Understanding the mechanisms that drive responses of carnivore density to prey depletion is not only crucial for conservation but also elucidates the balance between top-down and bottom-up limitations within the large carnivore guild. To avoid predation, competitively subordinate African wild dogs typically avoid their dominant competitors (lions) and the prey rich areas they are associated with, but no prior research has tested whether this pattern persists in ecosystems with anthropogenically-reduced prey density, and reduced lion density as a result.

Phosphorylation strongly affects the inhibition of human carbonic anhydrase I CO hydration activity.

Human carbonic anhydrases (hCAs) have essential roles in respiration, acid-base balance, and fluid secretion, with implications in diseases such as glaucoma, epilepsy, obesity, and cancer. Of the fifteen known hCAs, human CA I (hCA I) is particularly abundant in erythrocytes, playing a critical role in CO transport. Despite extensive research on hCA I, the impact of post-translational modifications (PTMs), particularly phosphorylation, on its catalytic activity and inhibitor binding remains poorly understood.

Cation induced changes to the structure of cryptophane cages.

Here the monocation complexes of seven -cryptophanes are examined with high-resolution ion-mobility mass spectrometry. The relative size of the [cation + cryptophane] complexes were compared based on their measured mobilities and derived collisional cross sections. A paradoxical trend of structural contraction was observed for complexes of increasing cation size.

Concise and Efficient Synthesis of Sequentially Isomeric Hetero[3]rotaxanes.

Stereoisomerism, stemming from the spatial orientation of components in molecular structures, plays a decisive role in nature. While the unconventional bonding found in mechanically interlocked molecules gives rise to unique expressions of stereochemistry, the exploration of their stereoisomers is still in its infancy. Sequence isomerism, characterized by variations in the ordering of mechanically interlocked components in catenanes and rotaxanes, mirrors the sequence variations found in biological macromolecules.

Photoswitchable Catalysis by a Self-Assembled Molecular Cage.

A heteroleptic [PdLL'] coordination cage containing a photoswitchable azobenzene-derived ligand catalyzes the Michael addition reaction between methyl vinyl ketone and benzoyl nitromethane within its cavity. The corresponding homoleptic cages are catalytically inactive. The heteroleptic cage can be reversibly disassembled and reassembled using 530 and 405 nm light, respectively, allowing catalysis within the cage to be switched and at will.

Protein Interaction Kinetics Delimit the Performance of Phosphorylation-Driven Protein Switches.

Post-translational modifications (PTMs) such as phosphorylation and dephosphorylation can rapidly alter protein surface chemistry and structural conformation, which can switch protein-protein interactions (PPIs) within signaling networks. Recently, -designed phosphorylation-responsive protein switches have been created that harness kinase- and phosphatase-mediated phosphorylation to modulate PPIs. PTM-driven protein switches are promising tools for investigating PTM dynamics in living cells, developing biocompatible nanodevices, and engineering signaling pathways to program cell behavior.

Binding of Per- and Polyfluoroalkyl Substances to β-Lactoglobulin from Bovine Milk.

Per- and polyfluoroalkyl substances (PFAS) are known for their high environmental persistence and potential toxicity. The presence of PFAS has been reported in many dairy products. However, the mechanisms underlying the accumulation of PFAS in these products remain unclear.

Successful introgression of wMel Wolbachia into Aedes aegypti populations in Fiji, Vanuatu and Kiribati.

Pacific Island countries have experienced periodic dengue, chikungunya and Zika outbreaks for decades. The prevention and control of these mosquito-borne diseases rely heavily on control of Aedes aegypti mosquitoes, which in most settings are the primary vector. Introgression of the intracellular bacterium Wolbachia pipientis (wMel strain) into Ae.

Characterisation of the heme aqua-ligand coordination environment in an engineered peroxygenase cytochrome P450 variant.

The cytochrome P450 enzymes (CYPs) are heme-thiolate monooxygenases that catalyse the insertion of an oxygen atom into the C-H bonds of organic molecules. In most CYPs, the activation of dioxygen by the heme is aided by an acid-alcohol pair of residues located in the I-helix of the enzyme. Mutation of the threonine residue of this acid-alcohol pair of CYP199A4, from the bacterium Rhodospeudomonas palustris HaA2, to a glutamate residue induces peroxygenase activity.

Pharmacological inhibition of TBK1/IKKε blunts immunopathology in a murine model of SARS-CoV-2 infection.

TANK-binding kinase 1 (TBK1) is a key signalling component in the production of type-I interferons, which have essential antiviral activities, including against SARS-CoV-2. TBK1, and its homologue IκB kinase-ε (IKKε), can also induce pro-inflammatory responses that contribute to pathogen clearance. While initially protective, sustained engagement of type-I interferons is associated with damaging hyper-inflammation found in severe COVID-19 patients.

Rapid In-Field Volatile Sampling for Detection of Infection in Wine Grapes.

Fungal infection of grape berries () by frequently coincides with harvest, impacting both the yield and quality of grape and wine products. A rapid and non-destructive method for identifying infection in grapes at an early stage prior to harvest is critical to manage loss. In this study, zeolitic imidazolate framework-8 (ZIF-8) crystal was applied as an absorbent material for volatile extraction from infected and healthy grapes in a vineyard, followed by thermal desorption gas chromatography-mass spectrometry.

Effects of Phosphorylation on the Activity, Inhibition and Stability of Carbonic Anhydrases.

Carbonic anhydrases (CAs) are a metalloenzyme family that have important roles in cellular processes including pH homeostasis and have been implicated in multiple pathological conditions. Small molecule inhibitors have been developed to target carbonic anhydrases, but the effects of post-translational modifications (PTMs) on the activity and inhibition profiles of these enzymes remain unclear. Here, we investigate the effects of phosphorylation, the most prevalent carbonic anhydrase PTM, on the activities and drug-binding affinities of human CAI and CAII, two heavily modified active isozymes.

Interpretable Machine Learning on Metabolomics Data Reveals Biomarkers for Parkinson's Disease.

The use of machine learning (ML) with metabolomics provides opportunities for the early diagnosis of disease. However, the accuracy of ML and extent of information obtained from metabolomics can be limited owing to challenges associated with interpreting disease prediction models and analyzing many chemical features with abundances that are correlated and "noisy". Here, we report an interpretable neural network (NN) framework to accurately predict disease and identify significant biomarkers using whole metabolomics data sets without feature selection.

Ion Heating in Advanced Dielectric Barrier Discharge Ion Sources for Ambient Mass Spectrometry.

Dielectric barrier discharges (DBD) are highly versatile plasma sources for forming ions at atmospheric pressure and near ambient temperatures for the rapid, direct, and sensitive analysis of molecules by mass spectrometry (MS). Ambient ion sources should ideally form intact ions, as in-source fragmentation can limit sensitivity, increase spectral complexity, and hinder interpretation. Here, we report the measurement of ion internal energy distributions for the four primary classes of DBD-based ion sources, specifically DBD ionization (DBDI), low-temperature plasma (LTP), flexible microtube plasma (FμTP), and active capillary plasma ionization (ACaPI), in addition to atmospheric pressure chemical ionization (APCI) using para-substituted benzylammonium thermometer ions.

Detection and prediction of Botrytis cinerea infection levels in wine grapes using volatile analysis.

Infection of grape berries (Vitis vinifera) by the fungus Botrytis cinerea (grey mould) frequently occurs in vineyards, resulting in off-flavours and other odours in wine and potential yield losses. In this study, volatile profiles of four naturally infected grape cultivars, and laboratory-infected grapes were analysed to identify potential markers for B. cinerea infection.

Identifying robust and reliable volatile organic compounds in human sebum for biomarker discovery.

Sebum from sebaceous glands is a rich source of volatile organic compounds (VOCs) that can readily be sampled non-invasively from the surface of skin. The VOC profiles of sebum can then be used to obtain information regarding different medical conditions including diabetes and Parkinson's Disease. However, the effects of sampling approaches and environmental factors on sebum VOC profiles are not established and the confident attribution of VOCs to disease states needs to be free of extraneous influences such as sampling materials and preparatory conditions.

On the Mechanism of Theta Capillary Nanoelectrospray Ionization for the Formation of Highly Charged Protein Ions Directly from Native Solutions.

Theta capillary nanoelectrospray ionization (θ-nanoESI) can be used to "supercharge" protein ions directly from solution for detection by mass spectrometry (MS). In native top-down MS, the extent of protein charging is low. Given that ions with more charge fragment more readily, increasing charge can enhance the extent of sequence information obtained by top-down MS.

Subjective Wellbeing among University Students and Recent Graduates: Evidence from the United Kingdom.

This study compares students' and recent graduates' perceptions of their subjective wellbeing and offers support mechanisms and resources to enhance wellbeing in higher education. Survey data were collected in September 2021 from 414 UK-based higher education students and recent graduates on their self-perceived subjective wellbeing in March 2020 (before COVID-19 regulations restrictions) and September 2021 (18 months later). Findings showed that subjective wellbeing scores fell for almost three-quarters of university students and recent graduates between March 2020 and September 2021.

Single-cell mass spectrometry.

Owing to recent advances in mass spectrometry (MS), tens to hundreds of proteins, lipids, and small molecules can be measured in single cells. The ability to characterize the molecular heterogeneity of individual cells is necessary to define the full assortment of cell subtypes and identify their function. We review single-cell MS including high-throughput, targeted, mass cytometry-based approaches and antibody-free methods for broad profiling of the proteome and metabolome of single cells.

Separation of disaccharide epimers, anomers and connectivity isomers by high resolution differential ion mobility mass spectrometry.

Glycans are ubiquitous, structurally diverse molecules that have specific and general roles involving metabolism, structure, and cell-to-cell signaling. Functional specificity depends strongly on the complexity of structures that polysaccharides can adopt based on their subunit composition, length, extent of branching, glycosidic bond connectivity and anomeric configuration. However, a rapid and comprehensive characterization of glycan isomers can be challenging owing to limitations associated with their separation.

An atmospheric pressure ion funnel with a slit entrance for enhancing signal and resolution in high resolution differential ion mobility mass spectrometry.

Differential ion mobility (DMS) is a versatile ion separation method that is often integrated with mass spectrometry (MS). In DMS, extremely high electric fields are used such that ion mobility depends non-linearly on electric field and thus, ion separations can be more orthogonal to MS than lower field ion mobility-based methods. DMS can have sufficiently high resolution to be used for enantiomer analysis of small molecules and to separate protein ions with peak widths comparable to those obtained for peptides.

Visible-Light Switching of Metallosupramolecular Assemblies.

A photoswitchable ligand and palladium(II) ions form a dynamic mixture of self-assembled metallosupramolecular structures. The photoswitching ligand is an ortho-fluoroazobenzene with appended pyridyl groups. Combining the E-isomer with palladium(II) salts affords a double-walled triangle with composition [Pd L ] and a distorted tetrahedron [Pd L ] (1 : 2 ratio at 298 K).