Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are widely recognised as two prevalent sexually transmitted infections that can have detrimental effects on women’s reproductive health. Previous research has concentrated on studying high-risk populations, resulting in limited epidemiological data regarding the general population. Therefore, the objective of this study was to estimate the prevalence of CT and NG among women attending public primary health care in Tlaxcala, Mexico. The study sample included 2,396 women already participating in the cervical cancer screening programme, from July to November 2014. After obtaining informed consent, the CT and NG tests were conducted on cervical samples, using a nucleic acid amplification test. We estimate the prevalence with 95% confidence intervals (CIs). Women who tested positive were promptly notified and provided with appropriate treatment. In our study population, CT and NG prevalences were 3.2 (95% CI: 2.6–4.0) and 0.01 (95% CI: 0.01–0.03), respectively. CT prevalence was higher in younger women (age < 40), although the results indicate a low prevalence; due to the potentially significant impact of CT and NG on women’s health, we require adequate surveillance, and guaranteeing rapid referral to the correct treatment is a priority for the control of these diseases.

The nutritional status is a determinant of the immune response that promotes a cellular homeostasis. In particular, adequate selenium levels lead to a better antioxidant and immune response. The aim of this work is to assess whether blood selenium levels, at time of SARS-CoV-2 infection, have an impact on the development and severity of COVID-19. A systematic review and meta-analysis of comparative and descriptive studies using MeSH terms, selenium and COVID-19 was performed. We searched bibliographic databases up to 17 July 2022 in PubMed and ScienceDirect. Studies that reported data on blood selenium levels were considered. A total of 629 articles were examined by abstract and title, of which 595 abstracts were read, of which 38 were included in the systematic review and 11 in the meta-analysis. Meta-analysis was conducted to mean difference (MD) with a 95 % confidence interval (CI), and heterogeneity was tested by I2 with random factors with a MD between selenium levels, mortality, morbidity and healthy subjects with a P-value of 0⋅05. Selenium levels were higher in healthy people compared to those in patients with COVID-19 disease (six studies, random effects MD: test for overall effect Z = 3⋅28 (P = 0⋅001), 97 % CI 28⋅36 (11⋅41–45⋅31), P < 0⋅00001), but without difference when compared with the degree of severity in mild, moderate or severe cases. In conclusion, the patients with active SARS-CoV-2 infection had lower selenium levels than the healthy population. More studies are needed to evaluate its impact on clinical severity through randomised clinical trials.

North African knapweed (Centaurea diluta Aiton), cornflower (Centaurea cyanus L.), corn marigold [Glebionis segetum (L.) Fourr.], rigid ryegrass (Lolium rigidum Gaudin), and corn poppy (Papaver rhoeas L.) are weeds of economic importance in the Iberian Peninsula, particularly due to limited herbicide options for effective control. For this reason, information about their seedling emergence has become critical to develop effective integrated management strategies and better time control actions. The aims of this study were to evaluate the effect of seed burial depth and soil disturbance on the emergence of these weed species. Two pot experiments were carried out to (1) quantify seedling emergence at three burial depths (2, 5, and 9 cm) and (2) characterize seedling emergence in response to different frequencies and timings of soil disturbance. Burial depth limited the emergence of G. segetum and P. rhoeas at 5 and 9 cm, respectively; while seedling emergence of C. diluta, C. cyanus, and L. rigidum were reduced by 92%, 90%, and 67% at 9 cm compared with 2 cm, respectively. Two or more sequential soil disturbance events increased total seedling emergence of C. diluta, P. rhoeas, and G. segetum compared with single events, while L. rigidum did not respond to repeated soil disturbance. These results suggest that turning the soil to bury weed seeds down to 5 cm or deeper would be a very effective method to control G. segetum and P. rhoeas and moderately effective to control C. cyanus. Also, the use of a stale seedbed would have some efficacy to reduce P. rhoeas and C. diluta weed pressure within the crop. This study illustrates how differences among species in seedling emergence in response to soil depth and disturbance can determine distinct emergence patterns ultimately influencing the selection of weed control tools and timing.

Using data from several well-preserved pyres, which are rarely found well preserved in the southwestern United States and northern Mexico, we examine cremation customs and their associated pyrotechnologies at the site of Cerro de Trincheras in northern Sonora, Mexico, from AD 1300 to 1450/1500. We explore variations in pyre construction and use, thermal alterations of the deceased, the deceased individuals’ biological profiles, the performance of mortuary rituals, and the sensorial experiences of both the mourners and the wider Cerro de Trincheras community. The residents of the site were masters of the pyrotechnologies associated with cremations, making efficient pyres for the deceased and maximizing their resources. The group also created transformative funeral rituals that may have facilitated and mediated a wide range of emotional responses toward their deceased.

Throughout the Late Pleistocene and Early Holocene, humans adapted to significant climate and environmental change. One key region for investigating these adaptive strategies is Island Southeast Asia, where fluctuating sea levels led to dramatic changes in coastlines, vegetation and fauna. The authors present new data from the re-excavation of Pilanduk Cave on Palawan Island, Philippines. The results corroborate the results of earlier excavations that identified Pleistocene occupation of the site. Pilanduk shows evidence for specialised deer hunting and freshwater mollusc consumption during the Last Glacial Maximum. The results add to the evidence for the shifting foraging behaviours of modern humans occupying variable tropical environments across Island Southeast Asia.

We studied the sperm whale Physeter macrocephalus in the Colombian Caribbean by combining data from our offshore surveys of behaviour, encounter rate, group structure and density with data from the literature. We describe for the first time the potential distribution of sperm whales in the Colombian Caribbean, using sighting and acoustic data obtained during our surveys, published information, and opportunistic encounters during 1988–2020. We conducted surveys on seismic vessels over 703 days during 2011–2016, covering an area of 68,904 km2. We recorded 98 individuals in a total of 50 groups, a density of 1.42 individuals per 1,000 km2. To determine the potential distribution of the species, we built Maxent models with uncorrelated environmental variables at five depths (from the surface to c. 2,000 m). The model for 1,000 m depth had the best performance, with areas of high probability of occurrence of sperm whales in the south and north-east Colombian Caribbean over the shelf break to waters up to c. 3,000 m deep, at a median distance of 107 km from the coast, and near the Archipelago of San Andrés, Old Providence and Saint Catherine in the north-west. This area may be an important tropical habitat for sperm whales, in which they socialize, rest, breed and feed. Our study underlines the importance of monitoring marine mammals offshore and describes the potential distribution of sperm whales in the Colombian Caribbean, supporting conservation actions for this Vulnerable species, which is currently facing several threats in this region.

By using innovative microlevel data from Colombia’s civil war, this article examines protests, one of many actions that civilians employ to resists peacefully armed actors during civil war. By using a cost-benefit analysis, the author argues that inhabitants can mobilize and solve their collective action problem when the costs of migrating or supporting one side in a war are too expensive. By examining the civil conflict on Colombia between 1988 and 2010, the author finds that civilians are likely to protest armed actors under three conditions. First, autonomous communities, which enjoy benefits associated with their territory, are likely to protest because migration would be costly; moreover, the institutional strength of these communities can decrease the costs of mobilization against armed actors. Second, foreign aid distributed through nongovernmental associations can empower individuals to take action by providing selective incentives for mobilization, thus decreasing costs. Last, high levels of violence, up to a certain threshold, increase the costs of nonparticipation and induce civilian action.

Trematode taxonomy is mainly based on the morphological traits of adults. The identification of metacercariae is challenging because such traits are not developed in larval forms, and they even may show some level of morphological variability. Studies testing the potential correspondence between morphological differences and genetic variation of parasites are still lacking. The metacercariae of Posthodiplostomum minimum are probably the diplostomids more widely distributed in North and Middle American freshwater fish, and their intraspecific morphological variability has been attributed to the effect exerted by the host. Here, we tested the hypothesis whether they represent a single species, or a species complex by assessing the genetic divergence and phylogenetic relationships of metacercariae sampled from several host species in a wide geographical range across Middle America. The internal transcribed spacers (ITS1-5.8S-ITS2), and the mitochondrial COI gene were sequenced for 124 and 55 metacercariae, respectively. Phylogenetic analysis inferred from ITS sequences uncovered six well-supported monophyletic lineages. The six lineages show no correspondence to any Posthodiplostomum species for which sequences are available thus far in GenBank. Lineages exhibit some degree of host specificity; Lineages I, II, IV and V are primarily parasites of cyprinodontiforms of the families Poeciliidae, Goodeidae, Profundulidae and Fundulidae. In poeciliids there are at least four candidate species of Posthodiplostomum, some of them occurring in sympatry; instead, Lineages II and VI are exclusively parasites of cichlids. This study contributes to our understanding of the diversity of larval forms of diplostomids and provides an opportunity to further study their life cycles.

The epidemiology behind multi-host/multi-parasite systems is particularly interesting to investigate for a better understanding of the complex dynamics naturally occurring in wildlife populations. We aimed to approach the naturally occurring polyparasitism of gastrointestinal nematodes in a sympatric wild ruminant scenario present in south-east Spain. To this end, the gastrointestinal tract of 252 wild ruminants of four different species (red deer, Cervus elaphus; mouflon, Ovis aries musimon; Iberian ibex, Capra pyrenaica and fallow deer, Dama dama) were studied in Cazorla, Segura y Las Villas Natural Park (Andalusia, Spain). Of the analysed animals, 81.52% were positive for parasite infection and a total of 29 nematode species were identified. Out of these, 25 species were detected in at least two host species and 11 parasitized all ruminant species surveyed. The multi-host interaction between these nematodes and the four host species is discussed under the perspective of host family-based differences.

The work focuses on the analysis of electrochemical corrosion in synthetic salt medium of the TiC/Ni-20Cr composite through the polarization curve technique at four exposure times (0, 6, 12 and 24 h). The composite was prepared by liquid infiltration of the liquid alloy into a porous body of TiC. It was found a continuous and homogeneous distribution of the reinforcing material in the interconnected matrix, having a residual porosity of 6.49 vol.%. According to the electrochemical results, in both samples the highest corrosion rate (CR) was obtained at 12 h exposure due to the rupture of the film of the corrosion products, allowing the interaction of chloride ions with the metal surface. The CR of the composite was slightly higher than that of the alloy at all exposure times, so that the presence of the reinforcing particles and the residual porosity reduce the corrosion resistance of the matrix in the composite. The mechanism of corrosion observed in the alloy and the composite was by pitting, however, the composite also presents crevice corrosion by a differential aeration cell mechanism formed between the metal matrix and the ceramic reinforcement, affected by the residual porosity as confirmed by electron microscopy examination.

The implantation and controlled release of growth factors can enhance the proliferation and differentiation of cells that promote new bone formation at defect sites. Therefore, chitosan polymer microspheres were prepared by the water-in-oil emulsion (W/O) method and solvent freeze-drying, using glutaraldehyde as an ionic crosslinker, along with the lyophilization of solvents, to microencapsulate growth factors, preventing denaturation. The microspheres were loaded with recombinant bone morphogenetic protein 2 (Rh-BMP-2). They were spherical in shape, with a rough surface ranging in particle size from 0.4 to 1.6 μm. The yield percentage with respect to the polymer was 70% and the BMP-2 load was regulated by the initial protein dose. BMP-2 release experiments were performed for 7 days in PBS solutions at pH 4 and 7.4. The results showed that the protein release rate was only 2% lower at pH 7.4. BMP-2/chitosan microspheres were compatible with the MG-63 cell line (ATCC®CRL-1427™Homo sapiens bone osteosarcoma) and could be considered drug delivery vehicles in bone tissue engineering applications.

The work presents an electrochemical study of the corrosion behaviour of two TiC/Cu-Ni metal matrix composites with a content of 10 and 20 wt.% Ni immersed in synthetic seawater. The composites were synthesized by a capillary infiltration technique, obtaining dense materials TiC/Cu-10Ni and TiC/Cu-20 Ni with a residual porosity of 1.8 and 1.7%, respectively. The corrosion rate (CR) was evaluated from the techniques of polarization curves (PC), linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS). Electrochemical measurements were carried out under static conditions, ambient temperature and atmospheric pressure at 24 hours exposure in the electrolytic medium. The corrosion rate is affected by the Ni content in the matrix, with less corrosion in the composite with a higher Ni content. The higher content of Ni in the Cu-Ni alloy provides higher passivation and stability to the corrosion products film that are absorbed on the composite surface. Microscopic examination (SEM) showed a characteristic morphology of a corrosion mechanism of the localized type (pits and crevices) generated by a differential aeration, where the TiC/Cu-10Ni composite showed greater degradation.