Search Results (9)

Morphological differences in the peripheral (sensory) and central (brain) nervous system may confer sensory and/or behavioral variation in elasmobranchs, both across taxa and throughout ontogeny. Over the last century, sea surface temperatures have increased over 0.5 °C and are predicted to rise 1–4 °C by the year 2100, potentially affecting species’ physiological performance negatively. As the nervous system of fishes grows continually throughout their lives, it may be highly plastic in response to environmental changes. This study examined the effects of increased rearing temperature on nervous system development in Port Jackson sharks (Heterodontus portusjacksoni). Egg cases (n = 21) were collected from Gulf St. Vincent (Adelaide, SA) and placed into either ambient (17.6 °C) or 3 °C above ambient seawater conditions through hatching and reared for up to five months post-hatch. Relative volumes of the eyes and nose (olfactory rosette) were quantified using magnetic resonance imaging, and relative brain size and size of major brain regions were compared between the two treatment groups. The size of the olfactory bulbs and tegmentum varied significantly between the treatment groups, which suggest differences in primary, secondary, or tertiary sensory processing and/or motor functions at elevated temperatures. While studies on acute responses to environmental conditions cannot inform true adaptation across broad timescales, understanding the effects of increased temperature on the brain phenotype can aid in predicting how elasmobranchs may fare in response to changing ocean conditions. Full article

Water scarcity and quality are critical impediments to sustainable crop production. In this study, HYDRUS-2D was calibrated using field measurements of water contents and salinities in the soil under wine grapes irrigated with river water (Rw, 0.32 dS/m). The calibrated model was then used to evaluate the impact of (a) four different water qualities ranging from 0.32 (Rw) to 3.2 dS/m (brackish water, Gw) including blended (Mix) and monthly alternating (Alt) irrigation modes; (b) two rainfall conditions (normal and 20% below normal); and (c) two leaching options (with and without 30 mm spring leaching irrigation) during the 2017–2022 growing seasons. Irrigation water quality greatly impacted root water uptake (RWU) by wine grapes and other water balance components. Irrigation with brackish water reduced average RWU by 18.7% compared to river water. Irrigation with blended water or from alternating water sources reduced RWU by 8.8 and 7%, respectively. Relatively small (2.8–8.2%) average annual drainage (Dr) in different scenarios produced a very low (0.05–0.16) leaching fraction. Modeling scenarios showed a tremendous impact of water quality on the salts build-up in the soil. The average electrical conductivity of the saturated soil extract (EC_e) increased three times with Gw irrigation compared to Rw (current practices). Blended and alternate irrigation scenarios showed a 21 and 28% reduction in EC_e, respectively, compared to Gw. Irrigation water quality substantially impacted site-specific actual basal (K_{cb act}) and single (K_{c act}) crop coefficients of grapevine. Threshold leaching efficiency estimated in terms of the salt mass leached vs. added (LE_s; kg/kg) for salinity control (LE_s > 1) was achieved with LFs of 0.07, 0.12, 0.12, and 0.15 for the Rw, Mix, Alt, and Gw irrigations, respectively. Applying annual leaching irrigation (30 mm) before bud burst (spring) in the Mix and Alt with Rw and Gw scenarios was found to be the best strategy for managing irrigation-induced salinity in the root zone, lowering the EC_e to levels comparable to irrigation with Rw. Modeling scenarios suggested that judicious use of water resources and continuous root zone monitoring could be key for salinity management under adverse climate and low water allocation conditions. Full article

This paper outlines and analyses preliminary research in South Australia’s Riverland, part of Australia’s largest river system, the Murray–Darling Basin, and one of the nation’s most important horticultural production areas. It focuses on the Renmark Irrigation Trust (RIT), which supplies water to c570 irrigators. Management of the Basin is controversial, with conflicting demands from stakeholders, including smallholder irrigators, broadacre farming, indigenous groups, and the environment. Climate change and the water market have contributed to uncertainty over environmental sustainability. Using sequential mixed methods, including a questionnaire survey, focus groups and interviews, we investigate the chief risks perceived by irrigators and their future-plans in face of concerns over variable water flows and economic uncertainty. We highlight the RIT’s contribution to river restoration and investigate its plans for additional on-farm water stewardship. We reveal high levels of uncertainty among irrigators regarding their future viability, including unintended consequences from the water market, the controversial role of water brokers, and environmental viability of the river system. The growth of ‘lifestyle blocks’ occupied by hobby farmers has added both to landscape diversity and fragmentation. To maintain a resilient horticultural industry, there may need to be adjustments to water management in the Basin to protect smallholders’ livelihoods whilst continuing to meet specified environmental needs. Full article

This study aimed to understand the experiences, barriers, and facilitators of rural general practitioners’ involvement with high-acuity patients. Semi-structured interviews with rural general practitioners in South Australia who had experience delivering high-acuity care were audio-recorded, transcribed verbatim, and analyzed through content and thematic approaches incorporating Potter and Brough’s capacity-building framework. Eighteen interviews were conducted. Barriers identified include the inability to avoid high-acuity work in rural and remote areas, pressure to handle complex presentations, lack of appropriate resources, lack of mental health support for clinicians, and impacts on social life. Enablers included a commitment to community, comradery in rural medicine, training, and experience. We concluded that general practitioners are a vital pillar of rural health service delivery and are inevitably involved in disaster and emergency response. While the involvement of rural general practitioners with high-acuity patients is complex, this study suggested that with the appropriate system, structure and role supports, rural general practitioners could be better empowered to manage high-acuity caseloads locally. Full article

Introduction: Understanding the specific geospatial variations in childhood stunting is essential for aligning appropriate health services to where new and/or additional nutritional interventions are required to achieve the Sustainable Development Goals (SDGs) and national targets. Objectives: We described local variations in the prevalence of childhood stunting at the second administrative level and its determinants in Nigeria after accounting for the influence of geospatial dependencies. Methods: This study used the 2018 national Nigeria Demographic and Health Survey datasets (NDHS; N = 12,627). We used a Bayesian geostatistical modelling approach to investigate the prevalence of stunting at the second administrative level and its proximal and contextual determinants among children under five years of age in Nigeria. Results: In 2018, the overall prevalence of childhood stunting in Nigeria was 41.5% (95% credible interval (CrI) from 26.4% to 55.7%). There were striking variations in the prevalence of stunting that ranged from 2.0% in Shomolu in Lagos State, Southern Nigeria to 66.4% in Biriniwa in Jigawa State, Northern Nigeria. Factors positively associated with stunting included being perceived as small at the time of birth and experience of three or more episodes of diarrhoea in the two weeks before the survey. Children whose mothers received a formal education and/or were overweight or obese were less likely to be stunted compared to their counterparts. Children who were from rich households, resided in households with improved cooking fuel, resided in urban centres, and lived in medium-rainfall geographic locations were also less likely to be stunted. Conclusion: The study findings showed wide variations in childhood stunting in Nigeria, suggesting the need for a realignment of health services to the poorest regions of Northern Nigeria. Full article

The current study investigated the trends and factors associated with the unmet need for family planning (FP) for limiting and spacing births among married Tanzanian women between 1999 and 2016. The study used Tanzania Demographic and Health Survey (TDHS) data for the years 1999 (N = 2653), 2004–2005 (N = 2950), 2010 (N = 6412), and 2015–2016 (N = 8210). Trends in the unmet need for FP were estimated over the study period. Multivariable multinomial logistic regression models were used to investigate the association between community-level, predisposing, enabling, and need factors with the unmet need for FP in Tanzania. The results showed no significant change in percentage of married women with an unmet need for birth spacing between 1999 and 2016. The proportion of married women with an unmet need for limiting births decreased from 9.5% (95% confidence interval (CI): 7.9%, 10.6%) in 1999 to 6.6% (95% CI: 5.9%, 7.3%) in 2016. Residing in a rural area, parity between 1–4 and 5+, visiting a health facility for any health services within twelve months, and planning to have more children (after two years and/or undecided) were factors positively associated with the unmet need for FP-spacing. Women with parity of 5+ were more likely to experience an unmet need for FP-limiting. Women’s age between 25–34 and 35–49 years, women’s employment status, watching television, women’s autonomy of not being involved in household decisions, and planning to have more children were factors associated with lower odds of having an unmet need for FP-spacing. Women’s age between 25–34 years, watching television, autonomy, and planning to have more children were factors with lower odds of having an unmet need for FP-limiting. Improving FP uptake among married Tanzanian women can reduce the unmet need for FP. Therefore, reducing unmet needs for FP is attainable if government policies and interventions can target women residing in rural areas and other modifiable risk factors, such as parity, health facility visits, planning to having more children, employment, watching television, and women’s autonomy. Full article

The evolution of strictly freshwater fishes in the Iberian Peninsula is correlated with the paleogeomorphological evolution of Iberian basins and mountain ranges. Located in Portugal’s central region, the Maciço Calcário Estremenho (MCE) is a unique limestone geological formation with river springs that separates two different biogeographic regions for freshwater ichthyofauna: at its western slope, small coastal streams with ancient connections to the Mondego Riverland, and at its eastern slope, sub-basins of the Tagus River. Springs from these rivers are located only a few kilometers apart and are typically seen as devoid of fish due to their intermittent regime, shallow water column, high slope, and/or existence of insurmountable barriers that virtually prevent upstream fish migration. Although the species richness is known for the region, little is known about which species have colonized the headwaters. The objectives of this study were to (1) assess which fish species are present at the springs and (2) characterize the genetic diversity at the inter- and intrapopulation levels of two target species (Achondrostoma oligolepis and Squalius pyrenaicus) existing on opposite slopes of the MCE, using one mitochondrial and one nuclear gene. Genetic analyses showed differences between populations from distinct rivers but also at the intrapopulation level, with unique haplotypes being found in some locations within a river basin. This study demonstrated that springs are not devoid of fish in the MCE and may instead be important conservation areas for native species, benefiting from the existing Natural Park established in the region. Despite their geographical proximity, the isolation of populations of the same species in distinct rivers resulted in significant interpopulation genetic differences. Moreover, intrapopulation genetic differences were also found, highlighting two important topics: the sampling scheme can influence the obtained genetic data and the genetic diversity may differ between upstream and downstream stretches of the same river. Sampling several locations within the same river leads, therefore, to more reliable results, and future landscape genetic studies using fast-paced markers are necessary to assess genetic connectivity and to depict how the genetic diversity of strictly freshwater fish species is distributed along a river course. Full article

Background: The severity of nausea and vomiting of pregnancy (NVP) correlates with pregnancy complications. This study aimed to confirm the measurement and structural invariance of the 24 h Pregnancy-Unique Quantification of Emesis and Nausea (PUQE-24) regarding parity and observation time among pregnant women during the first trimester. Methods: Questionnaires including the PUQE-24 and the Health-Related Quality of Life for Nausea and Vomiting during Pregnancy (NVP-QOL) questionnaire were distributed to pregnant women from 10 to 13 weeks of gestation who were attending antenatal clinics. There were 382 respondents, and of these, 129 responded to the PUQE-24 again one week later. Results: Confirmatory factor analysis of this single factor model showed a good fit with the data: CFI = 1.000. The PUQE-24 factor and NVP-QOL factor were strongly correlated (r = 82). Configural, measurement, and structural invariance of the factor structure of the PUQE items were confirmed between primiparas and multiparas as well as at the test and retest observation occasions. Conclusion: The findings suggested that using the PUQE-24 among pregnant women in the first trimester was robust in its factor structure. The PUQE-24 may be a promising tool as an easy and robust measure of the severity of nausea and vomiting among pregnant women. Full article

Changes in the environment, aiming at agricultural intensification, progressive urbanisation and other forms of anthropopression, may cause an increase in soil erosion and a resulting increase in the pollution inflow to surface water. At the same time, this results in increased nutrient pollution of bottom sediments. In this study, the concentrations of total nitrogen (TN), total phosphorus (TP), total organic carbon (TOC), calcium (Ca), iron (Fe) and potassium (K) were analysed using bottom sediment samples collected at 39 sites located along the entire length of the Warta River and its tributaries. Agricultural use of land adjacent to rivers was found to significantly degrade sediment quality, while anthropogenic land use (as defined by Corine Land Cover classification—CLC), unlike previous studies, reduces the pollution loads in the bottom sediments. Forest use also contributes to the reduction of the pollution load in sediments. It was found that the significance of the relationship between pollutant concentrations and land use depends on the length of the river–land interface. According to the analyses, the level of correlation between the analysed constituents depends on the use of land adjacent to rivers. The impact of agricultural land use has the strongest effect in the 1 km zone and 5 km in the case of anthropogenic land use. The results showed that the variability of total phosphorus TP concentrations is strongly correlated with the variability of iron concentrations. SPI values indicate that the risk to sediment quality is low due to TOC and Fe concentrations. In contrast, the risk of sediment pollution by TN and TP shows greater differentiation. Although the risk is negligible for 40% of the samples, at the same time, for 33% of the samples, a very high risk of pollution with both TN and TP was found. Full article