The global utilization of the physician assistant/associate (PA) is growing. Their increasing presence is in response to the rising demands of demographic changes, new developments in healthcare, and ...physician shortages. While PAs are present on four continents, the evidence of whether their employment contributes to more efficient healthcare has not been assessed in the aggregate. We undertook a systematic review of the literature on PA cost-effectiveness as compared to physicians. Cost-effectiveness was operationalized as quality, accessibility, and the cost of care.
Literature to June 2021 was searched across five biomedical databases and filtered for eligibility. Publications that met the inclusion criteria were categorized by date, country, design, and results by three researchers independently. All studies were screened with the Risk of Bias in Non-randomised Studies-of Interventions (ROBIN-I) tool. The literature search produced 4,855 titles, and after applying criteria, 39 studies met inclusion (34 North America, 4 Europe, 1 Africa). Ten studies had a prospective design, and 29 were retrospective. Four studies were assessed as biased in results reporting. While most studies included a small number of PAs, five studies were national in origin and assessed the employment of a few hundred PAs and their care of thousands of patients. In 34 studies, the PA was employed as a substitute for traditional physician services, and in five studies, the PA was employed in a complementary role. The quality of care delivered by a PA was comparable to a physician's care in 15 studies, and in 18 studies, the quality of care exceeded that of a physician. In total, 29 studies showed that both labor and resource costs were lower when the PA delivered the care than when the physician delivered the care.
Most of the studies were of good methodological quality, and the results point in the same direction; PAs delivered the same or better care outcomes as physicians with the same or less cost of care. Sometimes this efficiency was due to their reduced labor cost and sometimes because they were more effective as producers of care and activity.
In this study, a trait-based macroinvertebrate sensitivity modeling tool is presented that provides two main outcomes: (1) it constructs a macroinvertebrate sensitivity ranking and, subsequently, a ...predictive trait model for each one of a diverse set of predefined Modes of Action (MOAs) and (2) it reveals data gaps and restrictions, helping with the direction of future research. Besides revealing taxonomic patterns of species sensitivity, we find that there was not one genus, family, or class which was most sensitive to all MOAs and that common test taxa were often not the most sensitive at all. Traits like life cycle duration and feeding mode were identified as important in explaining species sensitivity. For 71% of the species, no or incomplete trait data were available, making the lack of trait data the main obstacle in model construction. Research focus should therefore be on completing trait databases and enhancing them with finer morphological traits, focusing on the toxicodynamics of the chemical (e.g., target site distribution). Further improved sensitivity models can help with the creation of ecological scenarios by predicting the sensitivity of untested species. Through this development, our approach can help reduce animal testing and contribute toward a new predictive ecotoxicology framework.
Pollution with microplastics has become an environmental concern worldwide. Yet, little information is available on the distribution of microplastics in lakes. Lake Ziway is one of the largest lakes ...in Ethiopia and is known for its fishing and drinking water supply. This study aims to examine the distribution of plastic particles, of all sizes (micro- and small macro-plastics) in four of the major fish species of the lake and in its shoreline sediment. The gastrointestinal tracts analysis showed that 35% of the sampled fishes ingested plastic particles. The median number of particles per fish was 4 (range 1–26). Benthic (Clarias gariepinus) and benthopelagic (Cyprinus carpio and Carassius carassius) fish species were found to contain a significantly higher number of plastic particles in comparison to the planktivorous fish species (Oreochromis niloticus). More fishes ingested plastic particles in the wet compared to the dry season. The maximum plastic size (40 mm fibre) was found in C. carpio. Estimated median mass of plastic particles in fish was 0.07 (0.0002–385.2) mg/kg_ww. Fish and sediment samples close to known potential sources of plastic particles had a higher plastic ingestion frequency (52% of the fish) and higher plastic concentration compared to the other parts of the lake. The median count and mass of plastic particles measured in sediment of the lake were 30,000 (400–124,000) particles/m3 and 764 (0.05–36,233) mg/kg_dw, respectively, the upper limits of which exceed known effect thresholds. Attenuated total reflection (ATR) - Fourier-transform infrared (FTIR) spectroscopy showed that polypropylene, polyethylene and alkyd-varnish were the dominant polymers in fishes and in sediment. The plastic particles size distributions were Log-linear and were identical for plastic particles found in fish and in sediment, suggesting strong benthic-pelagic coupling of plastic particles transfer.
Display omitted
•We studied microplastic and small macroplastic particles in an African lake.•We demonstrate temporal and spatial trends on the lake system level.•We demonstrate ingestion to be higher by benthic/benthopelagic than by pelagic fish.•Particle size analysis confirms benthic-pelagic transfer from sediment to fish.•Some of the plastic concentrations in sediment exceed known effect thresholds.
The lack of structural symmetry which usually characterizes semiconductor quantum dots lifts the energetic degeneracy of the bright excitonic states and hampers severely their use as high-fidelity ...sources of entangled photons. We demonstrate experimentally and theoretically that it is always possible to restore the excitonic degeneracy by the simultaneous application of large strain and electric fields. This is achieved by using one external perturbation to align the polarization of the exciton emission along the axis of the second perturbation, which then erases completely the energy splitting of the states. This result, which holds for any quantum dot structure, highlights the potential of combining complementary external fields to create artificial atoms meeting the stringent requirements posed by scalable semiconductor-based quantum technology.
In this commentary, I will discuss how climate warming might influence the impacts of chemicals on (aquatic) ecosystems. It provides a commentary on Sinclair et al. (2024).
Atopic dermatitis (AD) is a common T-helper 2 (Th2) lymphocyte-mediated chronic inflammatory skin disease characterized by disturbed epidermal differentiation (e.g.,
(
) expression) and diminished ...skin barrier function. Therapeutics targeting the aryl hydrocarbon receptor (AHR), such as coal tar and tapinarof, are effective in AD, yet new receptor ligands with improved potency or bioavailability are in demand to expand the AHR-targeting therapeutic arsenal. We found that carboxamide derivatives from laquinimod, tasquinimod, and roquinimex can activate AHR signaling at low nanomolar concentrations. Tasquinimod derivative (IMA-06504) and its prodrug (IMA-07101) provided full agonist activity and were most effective to induce
and other epidermal differentiation proteins, and counteracted IL-4 mediated repression of terminal differentiation. Partial agonist activity by other derivatives was less efficacious. The previously reported beneficial safety profile of these novel small molecules, and the herein reported therapeutic potential of specific carboxamide derivatives, provides a solid rationale for further preclinical assertation.
There has been considerable focus on the impacts of environmental change on ecosystem function arising from changes in species richness. However, environmental change may affect ecosystem function ...without affecting richness, most notably by affecting population densities and community composition. Using a theoretical model, we find that, despite invariant richness, (1) small environmental effects may already lead to a collapse of function; (2) competitive strength may be a less important determinant of ecosystem function change than the selectivity of the environmental change driver and (3) effects on ecosystem function increase when effects on composition are larger. We also present a complementary statistical analysis of 13 data sets of phytoplankton and periphyton communities exposed to chemical stressors and show that effects on primary production under invariant richness ranged from −75% to +10%. We conclude that environmental protection goals relying on measures of richness could underestimate ecological impacts of environmental change.
The ecosystem services (ES) approach is gaining broad interest in regulatory and policy arenas for use in landscape management and ecological risk assessment. It has the potential to bring greater ...ecological relevance to the setting of environmental protection goals and to the assessment of the ecological risk posed by chemicals. A workshop, organised under the auspices of the Society of Environmental Toxicology and Chemistry Europe, brought together scientific experts from European regulatory authorities, the chemical industry and academia to discuss and evaluate the challenges associated with implementing an ES approach to chemical ecological risk assessment (ERA).
Clear advantages of using an ES approach in prospective and retrospective ERA were identified, including: making ERA spatially explicit and of relevance to management decisions (i.e. indicating what ES to protect and where); improving transparency in communicating risks and trade-offs; integrating across multiple stressors, scales, habitats and policies. A number of challenges were also identified including: the potential for increased complexity in assessments; greater data requirements; limitations in linking endpoints derived from current ecotoxicity tests to impacts on ES.
In principle, the approach was applicable to all chemical sectors, but the scale of the challenge of applying an ES approach to general chemicals with widespread and dispersive uses leading to broad environmental exposure, was highlighted. There was agreement that ES-based risk assessment should be based on the magnitude of impact rather than on toxicity thresholds. The need for more bioassays/tests with functional endpoints was recognized, as was the role of modelling and the need for ecological production functions to link measurement endpoints to assessment endpoints. Finally, the value of developing environmental scenarios that can be combined with spatial information on exposure, ES delivery and service provider vulnerability was recognized.
Display omitted
•The ES approach has the potential to bring greater ecological relevance to ERA.•EU regulators, industry and academia all supported an ES approach in ERA.•ES approach is applicable to all chemical regulations but challenging for widely dispersive chemicals.•ES approach integrates across environmental policies, stressors, habitats and scales.•Tailor-made tools and models ES needed to link ecotoxicity measures to ES endpoints.
Topological multipole insulators are a class of higher-order topological insulators (HOTIs) in which robust fractional corner charges appear due to a quantized electric multipole moment of the bulk. ...This bulk-corner correspondence has been expressed in terms of a topological invariant computed using the eigenstates of the Wilson loop operator, a so-called “nested Wilson loop” procedure. We show that, similar to the unitary Floquet operator describing periodically driven systems, the unitary Wilson loop operator can realize “anomalous” phases that are topologically nontrivial despite having a trivial topological invariant. We introduce a concrete example of an anomalous HOTI, which has a quantized bulk quadrupole moment and fractional corner charges, but a vanishing nested Wilson loop index. An invariant able to capture the topology of this phase is then constructed. Our work shows that anomalous topological phases, previously thought to be unique to periodically driven systems, can occur and be used to understand purely time-independent HOTIs.
PDF
