Marine microorganisms play a crucial role in biogeochemical cycles, especially in the surface microlayer (SML), which differs from adjacent subsurface waters (SSW). In this study, we sampled the SML and SSW at 20 sites along the western Antarctic Peninsula during the summers of 2015 and 2019, examining microbial, viral and environmental differences. We focused on phototrophic protists, specifically Phaeocystis-like species, known for their high dimethylsulphoniopropionate (DMSP) contents, which can be released through viral lysis. DMSP is a precursor to dimethylsulphide (DMS), a gas influencing Earth’s climate. We hypothesized a significant relationship between Phaeocystis-like abundance and DMSP concentration, with strong interactions with their specific viruses (V4) in the SML. Most biotic variables showed higher mean values in the SML, although these differences often were not statistically significant. DMSP concentrations correlated with Phaeocystis-like species abundance in both layers (R2 = 0.482, P ≤ 0.01; R2 = 0.532, P ≤ 0.01, respectively), whereas V4 abundance significantly correlated with Phaeocystis-like species only in the SML (R2 = 0.572, P ≤ 0.01). These results suggest stronger interactions between viruses and DMSP-rich hosts in the SML, potentially increasing DMS emissions to the atmosphere and impacting climate regulation.

Before a binary system enters into a common envelope (CE) phase, accretion from the primary star onto the companion star through Roche Lobe overflow (RLOF) will lead to the formation of an accretion disk, which may generate jets. Accretion before and during the CE may alter the outcome of the interaction. Previous studies have considered different aspects of this physical mechanism. Here we study the properties of an accretion disk formed via 3D hydrodynamic simulations of the RLOF mass transfer between a 7 M$_{\odot}$, red supergiant star and a 1.4 M$_{\odot}$, neutron star companion. We simulate only the volume around the companion for improved resolution. We use a 1D implicit mesa simulation of the evolution of the system during 30 000 yr between the on-set of the RLOF and the CE to guide the binary parameters and the mass-transfer rate, while we simulate only 21 yr of the last part of the RLOF in 3D using an ideal gas quasi-isothermal equation of state. We expect that a pre-CE disk under these parameters will have a mass of $\sim 5\times 10^{-3}$ M$_{\odot}$ and a radius of $\sim40\ R_\odot$ with a scale height of $\sim 5\ R$$_{\odot}$. The temperature profile of the disk is shallower than that predicted by the formalism of Shakura and Sunyaev, but more reasonable cooling physics would need to be included. We stress test these results with respect to a number of physical and numerical parameters, as well as simulation choices, and we expect them to be reasonable within a factor of a few for the mass and 15% for the radius. We also contextualise our results within those presented in the literature, in particular with respect to the dimensionality of simulations and the adiabatic index. We discuss the measured accretion rate in the context of the Shakura and Sunyaev formalism and debate the viscous mechanisms at play, finishing with a list of prospects for future work.

Antarctic terrestrial ecosystems, covering less than 1% of the continent, are under increasing anthropogenic threats, particularly from climate change and tourism. This study focuses on the impact of human trampling on soil microbial communities in Barrientos Island (South Shetlands archipelago), a frequently visited location. Soil samples were collected within and at the edge of two established paths representing varying levels of human disturbance. Physical and chemical analyses revealed significant differences between the paths, potentially creating anaerobic conditions favorable for specific microbial taxa. Thus, microbial communities also differed between the paths. Aerobic heterotrophic taxa were dominant in the less disturbed path, while anaerobic taxa such as Bacteroidetes vadinHA17 thrived in the more compacted path. Although alpha diversity indices did not differ, beta diversity analyses showed notable distinctions, particularly between the paths rather than trampled and untrampled areas. These findings suggest that microbial communities may recover following the stop of human activity, but also that indigenous microbial communities or other overlooked factors may be influencing the recovery potential. This study thus offers a starting point for similar research, as it highlights the need for further investigation to determine whether human trampling or other environmental factors are primarily responsible for these differences.

This cross-sectional ecological study described fruit and vegetable (F&V) intake variability across 144 cities in 8 Latin American countries and by city-level contextual variables. Data sources came from health surveys and census data (Argentina, Brazil, Chile, Colombia, El Salvador, Guatemala, Mexico, and Peru). Self-reported frequency of F&V intake was harmonised across surveys. Daily F&V intake was considered as consumption 7 d of the week. Using a mixed-effects model, we estimated age and sex-standardised city prevalences of daily F&V intake. Through Kruskal–Wallis tests, we compared city F&V daily intake prevalence by tertiles of city variables related to women’s empowerment, socio-economics, and climate zones. The median prevalence for daily F&V intake was 55.7% across all cities (22.1% to 85.4%). Compared to the least favourable tertile of city conditions, F&V daily intake prevalence was higher for cities within the most favourable tertile of per capita GDP (median = 65.7% vs. 53.0%), labour force participation (median = 68.7% vs. 49.4%), women achievement-labour force score (median = 63.9% vs. 45.7%), and gender inequality index (median = 58.6% vs. 48.6%). Also, prevalences were higher for temperate climate zones than arid climate zones (median = 65.9% vs. 50.6%). No patterns were found by city level of educational attainment, city size, or population density. This study provides evidence that the prevalence of daily F&V intake varies across Latin American cities and may be favoured by higher socio-economic development, women’s empowerment, and temperate weather. Interventions to improve F&V intake in Latin America should consider the behaviour disparities related to underlying local social, economic, and climate zone characteristics.

We introduce a versatile high-repetition-rate solid tape target system suitable for relativistic laser-plasma driven secondary sources. We demonstrate the operation and stability monitoring based on a petawatt laser focused at 1 Hz. Experiments were carried out at the VEGA-3 laser system of the Centro de Láseres Pulsados facility where results for different tape materials and thicknesses are presented. Experimental proton spectra were recorded by a Thomson parabola spectrometer and a time-of-flight detector. In addition, non-invasive detectors, such as a target charging monitor and ionization chamber detectors, were tested as metrology for the stability of the source. Degradation of the proton signal at high-repetition-rate operation was observed and it was solved by online optimization of the relative focus position of the target and laser beam parameters. We report the use of the tape target for bursts of 1000 shots at 1 Hz with mean cut-off energies of about 10 MeV in optimized interaction conditions.

Objectives: Studies in PD have traditionally focused on motor features, however, interest in non-motor manifestations has increased resulting in improved knowledge regarding the prognosis of the disease. Although several studies have explored the incidence of dementia in PD cohorts, these studies have been conducted mainly in reference centers in high-income countries (HIC). In this study we aimed to analyze the prevalence of cognitive impairment in people with parkinsonism and PD and its association with incident dementia in a population- based study, of elderly from six Latin American countries.

Methods: This report consists of the analysis of data from a follow-up of 12,865 elderly people aged 65 years or older, carried out by 10/66 Dementia Research Group. Residents of urban and rural areas, from six low and middle- income countries (Cuba, Dominican Republic, Puerto Rico, Venezuela, Mexico and Peru). Exposures include parkinsonism and PD defined according to the UK Parkinson’s Disease Society Brain Bank diagnostic criteria. Cognitive impairment was the main exposure and dementia was measured through the dementia diagnosis algorithm from 10/66 DRG.

Results: At baseline, the overall prevalence of cognitive impairment was 14% (n = 1,581), in people with parkinsonism and PD, it was of 30.0% and 26.2%, respectively. Parkinsonism and PD were individually associated with prevalent and incident dementia after controlling for age, sex, and education. The pooled odds ratios from a fixed-effects meta-analysis were 2.2 (95% CI: 1.9 – 2.6) for parkinsonism and 1.9 (95% CI: 1.4 – 2.4) for PD. Regarding incident dementia, the pooled sub-Hazard ratio estimated using a competing risk model was 1.5 (95% CI: 1.2 –1.9) for parkinsonism and 1.5 (95% CI: 1.0 – 2.2) forPD.

Conclusions: Parkinsonism and PD were associated cross-sectionally with the presence of cognitive impairment, and prospectively with incident dementia in elderly people in the community population of Latin America studied. Systematic screening for cognitive impairment and dementia with valid tools in PD patients may help with earlier detection of those at highest risk for adverse outcomes. Identifying modifiable risk factors could potentially lead to efficient interventions even in advanced stages of PD.

Objectives: Because of the continued transition to older populations, various strategies have been developed to estimate the social impact and burden of health care. Regarding mental health, a strategy in the elderly is the measurement of neuropsychiatric symptoms (NPS), these include a wide range of behavioral and psychological manifestations. These are more frequent in the presence of some diseases, such as neurodegenerative syndromes, among which dementias and Parkinson’s disease (PD) stand out. The present study seeks to analyze the frequency of NPS, its relationship with the presence or absence of neurodegenerative syndromes and some characteristics of the elderly and caregivers.

Methods: This is an analysis of data from 12,865 elderly people evaluated within the protocols of the Dementia Research Group 10/66 in 6 Latin American countries (Cuba, Dominican Republic, Puerto Rico, Mexico, Venezuela and Peru). The presence or absence of parkinsonism, dementia and parkinsonism plus dementia (PDD) was identified through previously validated and published Methods. The NPS were assessed using the 12-symptom questionnaire version of the Neuropsychiatric Inventory. Other characteristics such as age, sex and education, in patients and caregivers; socioeconomic status, disability and comorbidities in the elderly; relationship with the elderly, needs and care-burden were assessed in careers.

Results: The most frequent symptoms were depression and sleep disorders in the four groups (without non-NDS neurodegenerative syndromes, parkinsonism, dementia and PDD, ranging from 23% to 49%. About a third of the elderly with parkinsonism, half of those with dementia, and 3 out of 5 of the elderly with PDD had 3 or more NPS. The odds ratios (OR) of each NPS measure by multivariate logistic regression models shown OR from 1.4 to 1.9 in the presence of parkinsonism; between 1.7 and 9.3 in the presence of dementia; and between 1.9 and 10.2 in the presence of PDD.

Conclusions: From a clinical and public mental health perspective, it is necessary to implement systematic Methods for NPS screening, as well as develop support strategies for families and caregivers, mainly of those with neurodegenerative syndromes.

Triatomines (Hemiptera: Heteroptera: Reduviidae) are hematophagous insects, well-known for their vectorial role in transmitting Trypanosoma cruzi Chagas (Kinetoplastida: Trypanosomatidae) parasites, the etiological agent of Chagas disease. Trapping these insects would limit human-triatomine interaction and, thus, control the disease. In this context, there is a critical need for effective lures to control triatomines. Through double-choice bioassays, we investigated the preference of Triatoma infestans Klug, T. pallidipennis Stal, and Rhodnius prolixus Stal triatomines for: (a) volatiles from fermented products (various fermentation types and substrates) and (b) commercial insect lures. Furthermore, we identified the chemical composition of these volatiles through headspace collection using Solid Phase Micro Extraction coupled with Gas Chromatograph-Mass Spectrometer (HS-SPME-GC-MS). Volatiles from lactic fermentation and certain fermented fruits, along with commercial lures, attracted triatomines, while other products exhibited possible repellent or dislodging properties. These findings hold promise for the control of triatomines and, ultimately, Chagas disease.

Adults of the genus Posthodiplostomum, Dubois, 1936 are parasites of fish-eating birds, mainly of the family Ardeidae, and are globally distributed. The genus currently comprises 35 species, although recent molecular evidence has shown that the diversity of the genus is underestimated since several candidate species have been recognized. In the Neotropical region of Mexico, at least 6 Posthodiplostomum lineages have been detected with metacercaria stages recovered from unrelated fish hosts. Here, we obtained adult specimens of Posthodiplostomum from 6 fish-eating birds representing 2 families (Butorides virescens, Ardea herodias, Nycticorax nycticorax, Tigrisoma mexicanum – Ardeidae, and Rynchops niger and Leucophaeus atricilla – Lariidae) from 4 localities in southern Mexico. Specimens were sequenced for 2 nuclear (28S and ITS1–5.8S–ITS2) and 1 mitochondrial (cox1) molecular marker. Phylogenetic analyses allowed us to link metacercariae and adult specimens and recognized a lineage, which was described morphologically. The new species can be distinguished from its congeners by its prosoma morphology and body size; this is the first described species in the Neotropical region of Mexico. Additionally, new host and locality records for P. macrocotyle and P. pricei are presented, expanding their geographical distribution range in the Americas.