Not Just Going with the Flow: The Effects of Fluid Flow on Bacteria and Plankton.

Microorganisms often live in habitats characterized by fluid flow, from lakes and oceans to soil and the human body. Bacteria and plankton experience a broad range of flows, from the chaotic motion characteristic of turbulence to smooth flows at boundaries and in confined environments. Flow creates forces and torques that affect the movement, behavior, and spatial distribution of microorganisms and shapes the chemical landscape on which they rely for nutrient acquisition and communication. Methodological advances and closer interactions between physicists and biologists have begun to reveal the importance of flow-microorganism interactions and the adaptations of microorganisms to flow. Here we review selected examples of such interactions from bacteria, phytoplankton, larvae, and zooplankton. We hope that this article will serve as a blueprint for a more in-depth consideration of the effects of flow in the biology of microorganisms and that this discussion will stimulate further multidisciplinary effort in understanding this important component of microorganism habitats.

A predatory gastrula leads to symbiosis-independent settlement in Aiptasia.

The planula larvae of the sea anemone Aiptasia have so far not been reported to complete their life cycle by undergoing metamorphosis into adult forms. This has been a major obstacle in their use as a model for coral-dinoflagellate endosymbiosis. Here, we show that Aiptasia larvae actively feed on crustacean nauplii, displaying a preference for live prey. This feeding behavior relies on functional stinging cells, indicative of complex neuronal control. Regular feeding leads to significant size increase, morphological changes, and efficient settlement around 14 d postfertilization. Surprisingly, the presence of dinoflagellate endosymbionts does not affect larval growth or settlement dynamics but is crucial for sexual reproduction. Our findings finally close Aiptasia's life cycle and highlight the functional nature of its larvae, as in Haeckel's Gastrea postulate, yet reveal its active carnivory, thus contributing to our understanding of early metazoan evolution.

A new chronology for the Maori settlement of Aotearoa (NZ) and the potential role of climate change in demographic developments.

Understanding the role of climate change, resource availability, and population growth in human mobility remains critically important in anthropology. Researching linkages between climate and demographic changes during the short settlement history of Aotearoa (New Zealand) requires temporal precision equivalent to the period of a single generation. However, current modeling approaches frequently use small terrestrial radiocarbon datasets, a practice that obscures past Maori population patterns and their connection to changing climate. Our systematic analysis of terrestrial and marine 14C ages has enabled robust assessments of the largest dataset yet collated from island contexts. This analysis has been made possible by the recent development of a temporal marine correction for southern Pacific waters, and our findings show the shortcomings of previous models. We demonstrate that human settlement in the mid to late 13th century AD is unambiguous. We highlight initial (AD 1250 to 1275) settlement in the North Island. The South Island was reached a decade later (AD 1280 to 1295), where the hunting of giant flightless moa commenced (AD 1300 to 1415), and the population grew rapidly. Population growth leveled off around AD 1340 and declined between AD 1380 and 1420, synchronous with the onset of the Little Ice Age and moa loss as an essential food source. The population continued to grow in the more economically stable north, where conditions for horticulture were optimal. The enhanced precision of this research afforded by the robust analysis of marine dates opens up unique opportunities to investigate interconnectivity in Polynesia and inform the patterns seen in other island contexts.

A transcriptome-wide analysis provides novel insights into how Metabacillus indicus promotes coral larvae metamorphosis and settlement.

BACKGROUND: Coral reefs experience frequent and severe disturbances that can overwhelm their natural resilience. In such cases, ecological restoration is essential for coral reef recovery. Sexual reproduction has been reported to present the simplest and most cost-effective means for coral reef restoration. However, larval settlement and post-settlement survival represent bottlenecks for coral recruitment in sexual reproduction. While bacteria play a significant role in triggering coral metamorphosis and settlement in many coral species, the underlying molecular mechanisms remain largely unknown. In this study, we employed a transcriptome-level analysis to elucidate the intricate interactions between bacteria and coral larvae that are crucial for the settlement process. RESULTS: High Metabacillus indicus strain cB07 inoculation densities resulted in the successful induction of metamorphosis and settlement of coral Pocillopora damicoris larvae. Compared with controls, inoculated coral larvae exhibited a pronounced increase in the abundance of strain cB07 during metamorphosis and settlement, followed by a significant decrease in total lipid contents during the settled stage. The differentially expressed genes (DEGs) during metamorphosis were significantly enriched in amino acid, protein, fatty acid, and glucose related metabolic pathways. In settled coral larvae induced by strain cB07, there was a significant enrichment of DEGs with essential roles in the establishment of a symbiotic relationship between coral larvae and their symbiotic partners. The photosynthetic efficiency of strain cB07 induced primary polyp holobionts was improved compared to those of the negative controls. In addition, coral primary polyps induced by strain cB07 showed significant improvements in energy storage and survival. CONCLUSIONS: Our findings revealed that strain cB07 can promote coral larval settlement and enhance post-settlement survival and fitness. Manipulating coral sexual reproduction with strain cB07 can overcome the current recruitment bottleneck. This innovative approach holds promise for future coral reef restoration efforts.

Identification of the principal neuropeptide MIP and its action pathway in larval settlement of the echiuran worm Urechis unicinctus.

BACKGROUND: Larval settlement and metamorphosis represent critical events in the life history of marine benthic animals. Myoinhibitory peptide (MIP) plays a pivotal role in larval settlement of marine invertebrates. However, the molecular mechanisms of MIP involved in this process are not well understood. RESULTS: In this study, we evaluated the effects of thirteen MIP mature peptides on triggering the larval settlement of Urechis unicinctus (Xenopneusta, Urechidae), and determined that MIP2 was the principal neuropeptide. Transcriptomic analysis was employed to identify differentially expressed genes (DEGs) between the MIP2-treated larvae and normal early-segmentation larvae. Both cAMP and calcium signaling pathways were enriched in the DEGs of the MIP2-treated larvae, and two neuropeptide receptor genes (Spr, Fmrfar) were up-regulated in the MIP2-treated larvae. The activation of the SPR-cAMP pathway by MIP2 was experimentally validated in HEK293T cells. Furthermore, fourteen cilia-related genes, including Tctex1d2, Cfap45, Ift43, Ift74, Ift22, Cav1 and Mns1, etc. exhibited down-regulated expression in the MIP2-treated larvae. Whole-mount in situ hybridization identified two selected ciliary genes, Tctex1d2 and Cfap45, were specially expressed in circumoral ciliary cells of the early-segmentation larvae. Knocking down Tctex1d2 mRNA levels by in vivo RNA interference significantly increased the larval settlement rate. CONCLUSION: Our findings suggest that MIP2 inhibits the function of the cilia-related genes, such as Tctex1d2, through the SPR-cAMP-PKA pathway, thereby inducing larval settlement in U. unicinctus. The study contributes important data to the understanding of neuropeptide regulation in larval settlement.

Variation in Oceanographic Resistance of the World's Coastlines to Invasion by Species With Planktonic Dispersal.

For marine species with planktonic dispersal, invasion of open ocean coastlines is impaired by the physical adversity of ocean currents moving larvae downstream and offshore. The extent species are affected by physical adversity depends on interactions of the currents with larval life history traits such as planktonic duration, depth and seasonality. Ecologists have struggled to understand how these traits expose species to adverse ocean currents and affect their ability to persist when introduced to novel habitat. We use a high-resolution global ocean model to isolate the role of ocean currents on the persistence of a larval-producing species introduced to every open coastline of the world. We find physical adversity to invasion varies globally by several orders of magnitude. Larval duration is the most influential life history trait because increased duration prolongs species' exposure to ocean currents. Furthermore, variation of physical adversity with life history elucidates how trade-offs between dispersal traits vary globally.

Lunar rhythms and their carry-over effects may shape environmental sex determination in a coral reef fish.

Lunar rhythms shape spawning phenology and subsequent risks and rewards for early life-history stages in the sea. Here, we consider a perplexing spawning phenology of the sixbar wrasse (Thalassoma hardwicke), in which parents spawn disproportionately around the new moon, despite the low survival of these larvae. Because primary sex determination in this system is highly plastic and sensitive to social environments experienced early in development, we ask whether this puzzling pattern of spawning is explained by fitness trade-offs associated with primary sexual maturation. We used otoliths from 871 fish to explore how spawning on different phases of the moon shapes the environments and phenotypes of settling larvae. Offspring that were born at the new moon were more likely to settle (i) before other larvae, (ii) at a larger body size, (iii) at an older age, (iv) to the best quality sites, and (v) as part of a social group-all increasing the likelihood of primary maturation to male. Selection of birthdates across life stage transitions suggests that the perplexing spawning phenology of adults may reflect an evolutionarily stable strategy that includes new moon spawning for compensatory benefits later in life, including preferential production of primary males at certain times.

Biofouling inhibition by Staphylococcus aureus extracts and their potential use for paints.

For the control of biofouling, some paints based on compounds that are toxic to marine organisms have been used. There is an intensive search for biodegradable solutions that are friendly to non-target organisms. Bacteria have been shown to be a source of compounds with antifouling potential. In this work, the antifouling activity of a strain of Staphylococcus aureus was evaluated. Extracts activity against biofilm-forming bacteria and the toxicity against Artemia franciscana were evaluated. The extracts were incorporated in a hard gel and a paint matrix, and they were exposed to the sea. In both the laboratory and field, we found that the compounds produced by S. aureus have antifouling activity. The non-toxicity of the tested extracts against Artemia franciscana nauplii suggests that the extracts obtained from S. aureus could have a low ecological impact over non-target organisms. Significant differences were found in the percentage of organisms cover in hard gels with extracts and control. After 90 days, important differences were also observed between the percentage of organisms cover of the paints that contained extracts and the control. Dichloromethane extract is the most effective for the inhibition or delay of the settlement of organisms For this reason, they could be used in matrices with different applications, such as in the shipping industry, aquaculture, or any other in which biofouling is a cause of inconvenience.

Movement of juvenile migratory birds from settlement to adulthood across the non-breeding range.

Among migratory vertebrates, high levels of fidelity to non-breeding sites during adulthood are common. If occupied sites vary in quality, strong site fidelity can have profound consequences for individual fitness and population demography. Given the prevalence of adult site fidelity, the regions of the non-breeding range to which juveniles first migrate, and the scale of any subsequent movements, are likely to be pivotal in shaping distributions and demographic processes across population ranges. However, inherent difficulties in tracking migratory individuals through early life mean that opportunities to quantify juvenile settlement and movements across non-breeding ranges, and the mechanisms involved, are extremely rare. Through long-term, range-wide resightings of hundreds of colour-marked individuals from their first migration to adulthood and the application of state-space models, we quantify levels of juvenile and adult regional-scale movements and distances at different life stages across the whole non-breeding distribution range in a migratory shorebird, the Black-tailed Godwit (Limosa limosa islandica). We show that the probability of individuals changing non-breeding regions (seven historical wintering regions spanning the Western Europe range) at all ages is very low (mean movement probability = 10.9% from first to subsequent winter, and 8.3% from first adult winter to later winters). Movement between regions was also low between autumn and winter of the same year for both juveniles (mean movement probability = 17.0%) and adults (10.4%). The great majority of non-breeding movements from the first autumn to adulthood were within regions and less than 100 km. The scarcity of regional-scale non-breeding movements from the first autumn to adulthood means that the factors influencing where juveniles settle will be key determinants of non-breeding distributions and of the rate and direction of changes in distributions.

Enteric bacterial agents associated with diarrhea and their antimicrobial sensitivity profiles in children under 5 years from mukuru informal settlement, Nairobi, Kenya.

BACKGROUND: In Kenya, diarrhoeal disease is the third leading cause of child mortality after malaria and pneumonia, accounting for nearly 100 deaths daily. We conducted a cross-sectional study in Mukuru informal settlements to determine the bacteria associated with diarrhea and their ASTs to provide data essential for implementing appropriate intervention measures. METHODS: Diarrheagenic children (≤ 5 years) were purposively recruited from outpatient clinics of Municipal City Council, Mukuru kwa Reuben, Medical Missionaries of Mary, and Mama Lucy Kibaki Hospital, Nairobi. A total of 219 stool samples were collected between May 2021 and August 2021. Stool culture was done on MacConkey and Salmonella Shigella agar, while the recovered bacteria were identified using VITEK®2GNID and polymerase chain reaction (PCR) used for E. coli pathotyping. Antibiotic Susceptibility Testing was done using VITEK®2AST-GN83. RESULTS: At least one bacterial organism was recovered from each of the 213 (97%) participants, with 115 (56%) participants having only one bacterial type isolated, 90 (43%) with two types of bacteria, and 2 (1%) with three types of bacteria recovered. The most predominant bacteria recovered was 85% (93/109) non-pathogenic E.coli and 15% (16/109)of pathogenic E.coli, with 2 (1%) were Enterohemorrhagic E.coli (EHEC), 6 (3%) were Enteroaggregative E.coli (EAEC), and 8 (4%) were Enteropathogenic E.coli (EPEC). Other potentially pathogenic bacteria included Enterobacter sp (27.8%), Klebsiella sp 33(11%), and Citrobacter sp 15(4.7%). Pathogenic isolates such as Salmonella 7 (2%), Proteus mirabilis 16 (6%), Providencia alcalifaciens 1 (0.3%), and Shigella 16 (4.7%) were detected. Isolates such as Pantoea spp 2(0.67%), Raoultella planticola 1(0.33%), and Kluyvera 6(2%) rarely reported but implicated with opportunistic diarrhoeal disease were also recovered. Ampicillin, cefazolin, and sulfamethoxazole-trimethoprim were the least effective antimicrobials at 64%, 57%, and 55% resistance, respectively, while meropenem (99%), amikacin (99%), tazobactam piperacillin (96%), and cefepime (95%) were the most effective. Overall, 33(21%) of all enterics recovered were multidrug-resistant. CONCLUSION: The study documented different bacteria potentially implicated with childhood diarrhea that were not limited to E. coli, Shigella, and Salmonella, as previously observed in Kenya. The strains were resistant to the commonly used antibiotics, thus narrowing the treatment options for diarrheal disease.

Retention of the highly educated migrants: from the perspective of urban e-service capability.

BACKGROUND: Talent is a crucial resource for economic and social development, serving as the driving force behind urban progress. As China experiences rapid growth in digital city construction, the capability of e-services continues to improve incessantly. In China, the new-generation highly educated migrants (NGHEMs) account for ~ 20-30% of the total floating populations. This study aimed to explore the settlement intention of new-generation highly educated migrations in China from the new perspective of urban e-service capabilities. Furthermore, the mechanism of the urban e-services on the settlement intention on the NGHEMs will be proved. METHODS: This paper employed data of China Migrants Dynamic Survey in 2017 and Evaluation Report of Government E-service Capability Index (2017). Descriptive analyses were conducted to investigate the factors influencing the settlement intention of NGHEMs in the destination city. Based on the principle of utility maximization, LASSO regression was employed to select individual and city characteristics that determined the settlement intention of NGHEMs. The impact of urban e-services on settlement intention was analyzed by using ordinal logit model. Additionally, robustness check, endogeneity analysis, and heterogeneity analysis were performed to validate the benchmark regression results. Finally, mediation model was employed to examine whether urban e-services enhance the settlement intention of NGHEMs by improving urban livability and urban innovation. RESULTS: The results indicate that the urban e-services promote the NGHEMs' settlement intention in the destination cities. Moreover, the results are still robust through a series of robustness tests. Furthermore, from the perspective of individual and regional heterogeneity, urban e-services significantly enhances the settlement intention of NGHEMs with male and female, married and urban household registration, and urban e-services can promote the settlement intention of NGHEMs with over 3 million inhabitants and those in the eastern regions of China. Finally, the intermediary effect test shows that urban e-services promote the settlement intention of NGHEMs through urban livability and urban innovation. CONCLUSION: This study highlights the important impact of urban e-services on the settlement intention of new-generation highly educated migrants. The conclusions of this study provide suggestions for the government to use when designing policies to enhance the settlement intention of the NGHEMs and to improve the development of urban e-services.

Sinking rates, orientation, and behavior of pennate diatoms.

Phytoplankton cells are now recognized as dynamic entities rather than as passive and isolated particles because they can actively modulate impacts of selection factors (nutrients, light, turbidity, and mixing) through a wide range of adaptations. Cell shape and/or chain length modulation is one of these processes but has predominantly been studied as an adaptation or an acclimatation to a specific growth limitation (light, nutrients, predation, etc.). In this study we have demonstrated that cell shape and size may have greater roles than previously known in phytoplankton ecology and species adaptation by permitting cell-to-cell signaling and more complex ecological processes that result from it. By exploring microscale biophysical interactions that lead to specific cell reorientation processes, we demonstrated that cell geometry not only modulates cell sinking rates but can also provide fast sensor responses to the cells' environment. Although gyrotaxis has been described in detail for motile phytoplankton cells, our findings illustrate that the reorientation process described here can occur even in non-motile cells within their natural environment. An additional consistent behavior was also recently described for a diatom species (Pseudo-nitzschia delicatessima), and with this study, we extend this observation to Pseudo-nitzschia pungens and Pseudo-nitzschia fraudulenta. Our observations emphasize the generality of this process, which adds a new level of complexity to our understanding of cellular interactions and their network of sensors.

Centring participant experience: a realist evaluation of a menstruator-friendly facility design project in a refugee settlement, Lebanon.

INTRODUCTION: Menstrual health in humanitarian contexts is a neglected topic. Its taboo nature presents difficulties for participants in menstrual health projects in these particularly challenging settings. Namely, their experiences may be concealed or overlooked in projects that are typically outcome focused. Realist Evaluation is a useful method to unearth and explore the hidden mechanisms and their causes, which lead to positive or negative participant experiences. The authors have applied this approach to a robust humanitarian menstrual health project to explore how to centre the emotional wellbeing of participants at all stages: prior to, during, and post-participation. STUDY SETTING: The project studied was led by the International Federation of Red Cross and Red Crescent Societies who piloted their adaptable manual for menstruator-friendly water, sanitation and hygiene (WaSH) facility design in humanitarian contexts. It was conducted by the Lebanese Red Cross in an informal tented settlement hosting Syrian refugees in Qaa, Lebanon. METHODS: The authors collected interview and focus group data on the contextual factors and processes within the project from nine project staff and 16 settlement inhabitants. They used a realist process of theory development, testing, and consolidation to understand how and under what circumstances the project inputs affected participants' wellbeing. RESULTS: The contextual factors and causal mechanisms promoting participant experience comprised individual (choices influencing and experience during participation), interpersonal (group dynamics and the role of non-menstruators), and organisational (expertise and knowledge, relationship to participants and cultural differences) factors. IMPLICATIONS: The research uses a case study from a renowned humanitarian organisation who provided a well-delivered project in a conducive environment to explore the mechanisms and contexts that can promote wider learning and refine understanding and programming in this under-researched and -theorised space. Specifically, it informs which contextual factors and project inputs must be present within a menstrual health project to ensure participant satisfaction whilst efficiently delivering well-designed menstruator-friendly WaSH facilities.

A comparison of the biofouling potential of field-collected and laboratory-cultured Ulva.

The marine algae Ulva spp. are commonly used as model biofouling organisms. As biofouling studies are primarily conducted using field-collected specimens, factors including species identity, seasonal availability, and physiological status can hinder the replicability of the results. To address these limitations, a protocol was developed for the on-demand laboratory culture and release of Ulva zoospores. The biofouling potential of laboratory-cultured and field-collected Ulva blades was compared using a waterjet. No significant differences were found between field and laboratory-cultured samples in either spore adhesion (before waterjet) or the proportion of spores retained after waterjet exposure. However, there was significant variability within each session type in pre- and post-waterjet exposures, indicating that spore adhesion and retention levels vary significantly among trial runs. In addition, all our laboratory cultures were Ulva Clade C (LPP complex). In contrast, our field samples contained a mix of Ulva Clade C, U. compressa clade I, and U. flexuosa Clade D. This protocol for on-demand production of Ulva spores can improve biofouling research approaches, enables comparison of results across laboratories and regions, and accelerate the development of anti-biofouling strategies.

Malnutrition in children under five years in a squatter settlement of Karachi: a case-control study.

BACKGROUND: Multidimensional factors such as socioeconomic or environmental factors influence malnutrition. Several studies have strongly linked malnutrition to poverty. Some international studies point to the worse nutritional status of urban slum children than rural children. Limited data is available regarding the nutritional status of slum children in Karachi. This study aimed to determine characteristics of malnourished children in an urban squatter settlement in Karachi, Pakistan. METHODS: A case- control study was carried out at the primary healthcare center of a squatter settlement in Karachi, Pakistan. All children under five years of age visiting the primary healthcare center were recruited consecutively. Cases were defined as children with z scores < -2 SD of WHO reference measurements of WFA, HFA, WFH and OFC. The controls were similar in terms of age group but had z scores between - 2SD and + 2SD. A self- structured risk factor questionnaire that included information about sociodemographic, economic and environmental factors as well as child- related characteristics was researcher administered via face-to-face interviews with the mothers of children. Univariate and multivariate logistic regression analyses were conducted. Crude and adjusted odds ratios were calculated with 95% confidence interval. RESULTS: A total of 280 participants including 140 cases and 140 controls participated in the study. A larger proportion of the sample originated from individuals with low household income. After adjusting for the confounders, childhood malnutrition was significantly associated with a low education level of father (aOR 4.86, 95% CI 2.23-10.60), a monthly income less than 25,000 PKR (89 USD) per month (aOR 7.13, 95% CI 1.67-30.54), pour pit latrine type of toilet (aOR 4.41, 95% CI 2.67-7.3), less than six months of exclusive breast feeding (aOR 3.578, CI 1.58-8.08), inappropriate weaning age (aOR 3.71, 95% CI 1.53-9). CONCLUSION: Malnutrition in children under five years of age in the community is associated with low family income, low paternal education, poor toilet facilities, lack of exclusive breastfeeding and inappropriate weaning age. The implementation of poverty reduction programs, sanitation provision at affordable rates, community-based breast feeding and weaning education intervention are urgently required to efficiently improve children's nutritional status.

Smoke exposure, hemoglobin levels and the prevalence of anemia: a cross-sectional study in urban informal settlement in Southern Ghana.

BACKGROUND: In sub-Saharan African cities, more than half of the population lives in informal settlements. These settlements are close to smoky dumpsites, industrial plants, and polluted roads. Furthermore, polluting fuels remain their primary sources of energy for cooking and heating. Despite evidence linking smoke and its components to anaemia, none of these studies were conducted on populations living in urban informal settlements. This study investigated the risks of anemia/mean Haemoglobin (HB) levels in an informal settlement in Accra, Ghana. Exposure to smoke was examined across various sources, encompassing residences, neighborhoods, and workplaces. METHODS: The study was a facility-based cross-sectional design among residents at Chorkor, an informal settlement in the Greater Accra region of Ghana. A questionnaire was administered at a community hospital during an interview to gather data on sources of smoke exposure in the household, in the neighbourhood, and in the workplace. A phlebotomist collected blood samples from the participants after the interview to assess their anaemia status. RESULTS: The population (n = 320) had a high prevalence of anemia, with 49.1% of people fitting the WHO's definition of anemia, while the average HB level was 12.6 ± 2.1 g/dL. Anemia was associated with the number of different types of waste burnt simultaneously [(1 or 2: prevalence ratio (PR): 95% confidence interval (CI), 1.14, 0.99-1.28: 3+: 1.16, 1.01-1.63, p-for-trend = 0.0082)], fuel stacking [(mixed stacking: 1.27, 1.07-1.20: dirty stacking:1.65, 1.19-2.25, p-for-trend = 0.0062)], and involvement in fish smoking (1.22, 0.99-1.06). However, the lower limit of the CIs for number of different forms of garbage burned simultaneously and engagement in fish smoking included unity. Reduced mean HB levels were associated with the number of different types of waste burnt simultaneously [(1 or 2: regression coefficient (ß): 95% confidence interval (CI), -0.01, -0.97- -0.99: 3+: -0.14, -0.77- -0.05)], current smoker [(yes, almost daily: -1.40, -2.01- -0.79: yes, at least once a month: -1.14, -1.79- -0.48)], Second-Hand-Smoking (SHS) (yes, almost daily: -0.77, -1.30- -0.21), fuel stacking [(mixed stacking-0.93, -1.33-0.21: dirty stacking-1.04, -1.60- -0.48)], any smoke exposure indicator in the neighbourhood (-0.84, -1.43- -0.25), living close to a major road (-0.62, -1.09- -0.49), and fish smoking (-0.41,-0.93- -0.12). CONCLUSION: Although the cross-sectional design precludes causality, smoke exposure was associated with mean HB levels and anaemia among populations living in informal settlements.

Prevalence of hypertension, diabetes mellitus, and their risk factors in an informal settlement in Freetown, Sierra Leone: a cross-sectional study.

BACKGROUND: Noncommunicable diseases (NCDs), especially hypertension and diabetes mellitus are on the increase in sub-Saharan Africa (SSA). Informal settlement dwellers exhibit a high prevalence of behavioural risk factors and are highly vulnerable to hypertension and diabetes. However, no study has assessed the prevalence of hypertension, diabetes, and NCDrisk factors among informal settlement dwellers in Sierra Leone. We conducted a study in June 2019 to determine the prevalence of hypertension, diabetes, and NCD risk factors among adults living in the largest Sierra Leonean informal settlement (KrooBay). METHODS AND MATERIALS: We conducted a community-based cross-sectional survey among adults aged ≥ 35 years in the KrooBay community. Trained healthcare workers collected data on socio-demographic characteristics and self-reported health behaviours using the World Health Organization STEPwise surveillance questionnaire for chronic disease risk factors. Anthropometric, blood glucose, and blood pressure measurements were performed following standard procedures. Logistics regression was used for analysis and adjusted odd ratios with 95% confidence intervals were calculated to identify risk factors associated with hypertension. RESULTS: Of the 418 participants, 242 (57%) were females and those below the age of 45 years accounted for over half (55.3%) of the participants. The prevalence of smoking was 18.2%, alcohol consumption was 18.8%, overweight was 28.2%, obesity was 17.9%, physical inactivity was 81.5%, and inadequate consumption of fruits and vegetables was 99%. The overall prevalence of hypertension was 45.7% (95% CI 41.0-50.5%), systolic hypertension was 34.2% (95% CI 29.6-38.8%), diastolic blood pressure was 39.9% (95% CI 35.2-44.6), and participants with diabetes were 2.2% (95% CI 0.7-3.6%). Being aged ≥ 55 years (AOR = 7.35, 95% CI 1.49-36.39) and > 60 years (AOR 8.05; 95% CI 2.22-29.12), separated (AOR = 1.34; 95% 1.02-7.00), cohabitating (AOR = 6.68; 95% CL1.03-14.35), vocational (AOR = 3.65; 95% CI 1.81-7.39 ) and having a university education (AOR = 4.62; 95% CI 3.09-6.91) were found to be independently associated with hypertension. CONCLUSION: The prevalence of hypertension,and NCD risk factors was high among the residents of the Kroobay informal settlement. We also noted a low prevalence of diabetes. There is an urgent need for the implementation of health education, promotion, and screening initiatives to reduce health risks so that these conditions will not overwhelm health services.

A scoping review on the barriers to and facilitators of health services utilisation related to refugee settlement in regional or rural areas of the host country.

BACKGROUND: Healthcare access and equity are human rights. Worldwide conflicts, violence, and persecution have increased the number of people from refugee or refugee-like backgrounds. Because urban areas are already densely populated, governments have aimed to increase refugee resettlement in rural and/or regional areas. Because of the complex healthcare needs of refugees, this creates challenges for healthcare service providers. Identifying barriers to accessing healthcare in rural areas is therefore important to better inform policy settings and programmes that will provide culturally appropriate patient-centred care to the refugee community. METHODS: This review scoped 22 papers written in English between 2018 and July 2023 from five countries (Australia, New Zealand, Germany, Bangladesh, and Lebanon) in order to provide an overview of the barriers and possible solutions to facilitate refugees' access to healthcare. RESULTS: The reviewed literature summarised the perceptions of at least 3,561 different refugees and 259 rural health service providers and/or administrators and identified major challenges. These include communication (illiteracy in the resettlement country language and lack of a suitable interpreter), lack of cultural awareness of health services, discrimination, and access difficulties (transportation, availability of health specialist services, cost). As a consequence, it was identified that improving access to affordable housing, employment through credential recognition, competence-level education for children, facilitating language training, and adapting health information would increase resettlement and encourage access to healthcare. CONCLUSIONS: Refugees face significant barriers to accessing and engaging with healthcare services. This impacts their integration into rural communities and increases the prevalence of psychosocial issues like feelings of loneliness, low self-esteem, a lack of autonomy, and a lack of empowerment over informed decision-making, especially for women, jobless men, and the elderly. These findings support the need for additional support for refugees and healthcare providers to improve language proficiency and cultural competency. Policymakers need to improve the availability and accessibility of employment, housing accessibility, and service mobility. Additionally, more research is needed to assess the efficacy of emerging innovative programmes that aim to close the gap by delivering culturally appropriate patient-centred care to refugee communities in rural areas.

Ancient DNA from Guam and the peopling of the Pacific.

Humans reached the Mariana Islands in the western Pacific by ∼3,500 y ago, contemporaneous with or even earlier than the initial peopling of Polynesia. They crossed more than 2,000 km of open ocean to get there, whereas voyages of similar length did not occur anywhere else until more than 2,000 y later. Yet, the settlement of Polynesia has received far more attention than the settlement of the Marianas. There is uncertainty over both the origin of the first colonizers of the Marianas (with different lines of evidence suggesting variously the Philippines, Indonesia, New Guinea, or the Bismarck Archipelago) as well as what, if any, relationship they might have had with the first colonizers of Polynesia. To address these questions, we obtained ancient DNA data from two skeletons from the Ritidian Beach Cave Site in northern Guam, dating to ∼2,200 y ago. Analyses of complete mitochondrial DNA genome sequences and genome-wide SNP data strongly support ancestry from the Philippines, in agreement with some interpretations of the linguistic and archaeological evidence, but in contradiction to results based on computer simulations of sea voyaging. We also find a close link between the ancient Guam skeletons and early Lapita individuals from Vanuatu and Tonga, suggesting that the Marianas and Polynesia were colonized from the same source population, and raising the possibility that the Marianas played a role in the eventual settlement of Polynesia.

Deep genetic affinity between coastal Pacific and Amazonian natives evidenced by Australasian ancestry.

Different models have been proposed to elucidate the origins of the founding populations of America, along with the number of migratory waves and routes used by these first explorers. Settlements, both along the Pacific coast and on land, have been evidenced in genetic and archeological studies. However, the number of migratory waves and the origin of immigrants are still controversial topics. Here, we show the Australasian genetic signal is present in the Pacific coast region, indicating a more widespread signal distribution within South America and implicating an ancient contact between Pacific and Amazonian dwellers. We demonstrate that the Australasian population contribution was introduced in South America through the Pacific coastal route before the formation of the Amazonian branch, likely in the ancient coastal Pacific/Amazonian population. In addition, we detected a significant amount of interpopulation and intrapopulation variation in this genetic signal in South America. This study elucidates the genetic relationships of different ancestral components in the initial settlement of South America and proposes that the migratory route used by migrants who carried the Australasian ancestry led to the absence of this signal in the populations of Central and North America.