Does stream secondary salinization affect fungal and detritus palatability to shredders?

BELIHU, Tesfalem Getahun - Does stream secondary salinization affect fungal and detritus palatability to shredders? . Coimbra : [s.n.], 2015. Dissertação de Mestrado em Ecologia.A salinização por factores antropogénicos é considerada uma das principais ameaças ambientais que levam à degradação da qualidade da água e à alteração da biodiversidade aquática. No entanto, pouco se sabe acerca dos seus efeitos na decomposição foliar microbiana e na palatabilidade para os trituradores. Neste estudo, foi usado um microcosmos para avaliar o efeito da salinidade (4 g/L NaCl) na atividade respiratória e de decomposição de espécies de fungos isoladas. Comparámos também a importância do tipo de fungo e da salinização na qualidade foliar para o triturador endémico Sericostoma vittatum Rambur (Sericostomatidae), mantido em ambientes diferentes – com e sem contaminação salina. Foram escolhidas folhas de carvalho e de amieiro para a realização do estudo. A salinidade a uma concentração de 4g/L NaCl não afetou as atividades de decomposição fúngica, nem nas folhas de carvalho nem nas de amieiro, mas foi possível observar uma estimulação da degradação de amieiro no meio com contaminação salina. Foram detetados efeitos adversos da salinidade na respiração microbiana para ambos os tipos de folhas. O consumo de amieiro pelas larvas de Sericostoma vittatum foi menor na presença de sal. Pelo contrário, foi detetado um comportamento alimentar compensatório das larvas em relação às folhas de carvalho condicionadas em meio salino quando oferecidas em meio salino. Os resultados indicam que a concentração testada (4 g/L) não prejudica a decomposição mediada por fungos. No entanto, os efeitos da contaminação salina em fungos são específicos para cada espécie e podem afetar o comportamento alimentar dos invertebrados. As respostas promovidas pela contaminação salina, a nível da água e da dieta, parecem capazes de afetar a performance dos invertebrados, especialmente quando as folhas disponíveis são mais recalcitrantes. Se generalizados, os resultados deste estudo indicam que é possível esperar efeitos importantes nos ciclos de nutrientes de cursos de água devido à contaminação salina.Anthropogenic salinization has been considered as one of the main environmental threats leading to water quality degradation and alteration of aquatic biodiversity. However, little is known about its effects on microbial mediated leaf decomposition and leaf palatability to shredders. In this study we conducted a microcosm experiment to assess the effect of salinity (4g/L NaCL) on individual fungal species’ respiration and decomposition activity. We also compared the importance of fungal identity and salinization on leaf quality to the common endemic shredder Sericostoma vittatum Rambur (Sericostomatidae) maintained in both contaminated and non-contaminated environments. For this purpose, oak and alder leaves were selected. We found that salinity at a concentration of 4g/L NaCl did not affect the fungal decomposition activities in oak or alder leaves although a stimulation of alder degradation could be observed in salt-contaminated media. Adverse effects of salinity was observed in microbial respiration on both leaf species. Consumption of alder by Sericostoma vittatum larvae was depressed by the presence of salt. On the contrary, a compensatory feeding behaviour of the larvae towards oak leaves conditioned in salt media and when offered in salt media was detected. The results indicate that the tested concentration (4g/L) does not impair fungalmediated decomposition. However, the effects of salt contamination on fungal species are species specific and may affect invertebrates feeding behaviour. Dietary and waterborne effects promoted by salt contamination seem able to affect invertebrates’ performance particularly if available leaves are more recalcitrant. If generalised the present results indicate that important effects on streams nutrient cycling maybe expected due to salt contamination

Hand hygiene status and its associated factors among housemaids working in communal living residences in Jimma city, southwest Ethiopia

Objective: Hand hygiene is a milestone, cost-effective, and convenient strategy to prevent the transfer of pathogenic micro-organisms. However, housemaids operating inside a kitchen can be the source of infection. In addition, hand hygiene among housemaids working in dwellings was underexplored. This study aimed to assess the hand hygiene status and associated factors among housemaids working in communal living residences in Jimma City, Southwest Ethiopia. Methods: A total of 230 housemaids were included in this cross-sectional study. Total samples were proportionally allocated for each residence and a simple random sampling technique was applied to select the study participants. Hand hygiene status and relevant characteristics were collected through face-to-face interviews and observations. Hand swab samples were collected and tested for bacterial contaminants. Then, it was inoculated aseptically using streak-plating methods on mannitol salt agar (MSA), MacConkey agar (MCA), salmonella-shigella agar (SSA), and eosin methylene blue (EMB) agar and then incubated at 37 °C for 24 h. Data was edited, cleaned, and double-entered into Epidata version 3.1 and then exported to the statistical package for social science statistics version 26 for further analysis. Binary logistic regression was used to identify associated factors. Statistically significant was declared at P value < 0.05. Results: Two hundred twenty-five housemaids were interviewed with a response rate of 97.8 %. The results showed that the proportion of good hand hygiene status among the housemaids was only 28.0 %. Although the majority of participants reported washing their hands frequently, the prevalence of bacterial contaminants on their hands was high at 72 %. The study identified several factors associated with hand hygiene status, including the occupational status of heads of households (AOR = 0.030, 95 % CI: 0.003, 0.348; P = 0.0050), the effectiveness of the heads of household (AOR = 13.955, 95 % CI: 1.442, 13.500; P = 0.0230), and the removal of accessories during handwashing (AOR = 20.844, 95 % CI: 2.190, 9.842; P = 0.0080). Conclusion: Overall, the hand hygiene status of housemaids was found to be poor and influenced by demographics and other relevant characteristics. The study emphasizes the need for a multimodal strategy involving household heads, local and national authorities, and other stakeholders to raise awareness and advocate for hand hygiene to prevent communicable diseases in the wider community, particularly in the study area