Bellwethers of change: population modelling of North Pacific humpback whales from 2002 through 2021 reveals shift from recovery to climate response.

For the 40 years after the end of commercial whaling in 1976, humpback whale populations in the North Pacific Ocean exhibited a prolonged period of recovery. Using mark-recapture methods on the largest individual photo-identification dataset ever assembled for a cetacean, we estimated annual ocean-basin-wide abundance for the species from 2002 through 2021. Trends in annual estimates describe strong post-whaling era population recovery from 16 875 (± 5955) in 2002 to a peak abundance estimate of 33 488 (± 4455) in 2012. An apparent 20% decline from 2012 to 2021, 33 488 (± 4455) to 26 662 (± 4192), suggests the population abruptly reached carrying capacity due to loss of prey resources. This was particularly evident for humpback whales wintering in Hawai'i, where, by 2021, estimated abundance had declined by 34% from a peak in 2013, down to abundance levels previously seen in 2006, and contrasted to an absence of decline in Mainland Mexico breeding humpbacks. The strongest marine heatwave recorded globally to date during the 2014-2016 period appeared to have altered the course of species recovery, with enduring effects. Extending this time series will allow humpback whales to serve as an indicator species for the ecosystem in the face of a changing climate.

A collaborative and near-comprehensive North Pacific humpback whale photo-ID dataset.

We present an ocean-basin-scale dataset that includes tail fluke photographic identification (photo-ID) and encounter data for most living individual humpback whales (Megaptera novaeangliae) in the North Pacific Ocean. The dataset was built through a broad collaboration combining 39 separate curated photo-ID catalogs, supplemented with community science data. Data from throughout the North Pacific were aggregated into 13 regions, including six breeding regions, six feeding regions, and one migratory corridor. All images were compared with minimal pre-processing using a recently developed image recognition algorithm based on machine learning through artificial intelligence; this system is capable of rapidly detecting matches between individuals with an estimated 97-99% accuracy. For the 2001-2021 study period, a total of 27,956 unique individuals were documented in 157,350 encounters. Each individual was encountered, on average, in 5.6 sampling periods (i.e., breeding and feeding seasons), with an annual average of 87% of whales encountered in more than one season. The combined dataset and image recognition tool represents a living and accessible resource for collaborative, basin-wide studies of a keystone marine mammal in a time of rapid ecological change.

Does staff eRostering boost patient outcomes?

The introduction of eRostering to Nottingham University Hospitals Trust highlighted several nursing issues that needed to be addressed but had not previously been fully understood. The eRostering system has given ward managers a better understanding of nursing availability, which has led to improved patient outcomes.

Columnar mesomorphism from hemi-disklike metallomesogens derived from 2,6-bis[3',4',5'-tri(alkoxy)phenyliminomethyl]pyridines (L): crystal and molecular structures of [M(L)Cl2] (M=Mn, Ni, Zn).

Four new series of non-disklike complexes of general formula [MCl(2)(L(n))] based upon substituted 2,6-bis(3',4',5'-trialkoxyphenyliminomethyl)pyridine ligands (L(n)) and with M=Zn(II), Co(II), Mn(II), and Ni(II) have been prepared and examined for liquid crystallinity. A complete analysis of the thermal behavior by polarized-light optical microscopy, differential scanning calorimetry, and small-angle Xray scattering revealed a rich and varied mesomorphism. Moreover, the high thermal stability of the compounds leads to rather extended mesomorphic ranges. The nature and thermal stability of each mesophase depend on both the length of the six terminal alkoxy chains, n (n=8, 10, 12, 14, 16), and on the metal ions. As demonstrated by small-angle Xray diffraction experiments, the mesomorphism of these complexes is solely of the columnar type. One compound shows an oblique columnar phase, while most of them show a hexagonal columnar phase, Col(h), and several types of rectangular columnar phase, Col(r). Xray single-crystal structures obtained for three methoxy derivatives confirm the 1:1 metal-ligand stoichiometry of the complexes, in which the metal is pentacoordinate with a distorted, trigonal bipyramidal geometry. The crystalline structures also reveal the existence of some columnar organization in the solid state, the columns resulting from an alternated stacking of the complexes in one direction. By combining these results with those obtained from dilatometry experiments, a model for the molecular organization within the mesophases is proposed in which an antiparallel arrangement of the metallomesogens is retained in the mesophase.

Compartmental Schiff-base ligands as selective double-loaded extractants for copper(II).

The Robson compartmental macrocyclic ligand derived from the condensation of derivatives of 2,6-diformylphenol and diamines has been prepared for the first time in its free ligand form; competitive three-phase transport and two-phase extraction studies confirm high double-loaded selectivity for the binding and delivery of Cu(II).