Long-term changes as oil palm plantation age simplify the structure of host-parasitoid food webs.

Understanding host-parasitoid food webs, as well as the factors affecting species interactions, is important for developing pest management strategies in an agroecosystem. This research aimed to study how the long-term change in oil palm plantations, specifically the tree age, affect the structure of host-parasitoid food webs. The field research was conducted on an oil palm plantation located in Central Kalimantan and Jambi Province, Indonesia. In Central Kalimantan, we conducted observations of lepidopteran larvae and parasitoid wasps at different tree ages, ranging from 3 to 18 years old. For tree ages from 3 to 10 years, observations of host-parasitoid food webs were conducted by collecting the lepidopteran larvae using a hand-collection method in each oil palm tree within a hundred trees and they were later reared in the laboratory for observing the emerging parasitoids. The fogging method was applied for trees aged 12 to 18 years because the tree height was too high, and hand-collection was difficult to perform. To compare host-parasitoid food webs between different regions, we also conducted a hand-collection method in Jambi, but only for trees aged 3 years old. The food-web structure that was analyzed included the species number of lepidopteran larvae and parasitoid wasps, linkage density, and interaction diversity. We found 32 species of lepidopteran pests and 16 species of associated parasitoids in Central Kalimantan and 12 species of lepidopteran pests, and 11 species of parasitoids in Jambi. Based on the GLM analysis, tree age had a negative relationship with the species number of lepidopteran larvae and parasitoids as well as linkage density and interaction diversity. Different geographical regions showed different host-parasitoid food web structures, especially the species number of lepidopteran larvae and interaction diversity, which were higher in Central Kalimantan than in Jambi. However, some parasitoids can be found across different tree ages. For example, Fornicia sp (Hymenoptera: Braconidae) was recorded in all ages of oil palm sampled. Results of the GLM analysis showed that the abundance of Fornicia sp and its host (lepidopteran larvae abundance) were not affected by the tree age of the oil palm. In conclusion, the long-term change in oil palm plantations simplifies the structure of host-parasitoid food webs. This highlights the importance of long-term studies across geographical regions for a better understanding of the consequences that wide monoculture oil palm plantations have on biological control services.

Correlations Among Maternal and Infant Factors, Lead Exposure, and Serum Prolactin Levels During Lactation: A Cross-sectional Study in Indonesia.

OBJECTIVES: Prolactin is vital for breastfeeding and milk production, and its secretion is influenced by factors related to the mother, infant, and environment. To date, no study has concurrently investigated the correlation of these factors with serum prolactin levels during lactation. Therefore, the objective of this study was to investigate the correlations among maternal and infant factors, lead exposure, and serum prolactin levels during lactation. METHODS: A cross-sectional approach was employed in Surabaya, Indonesia, among 110 exclusively lactating mothers. The mothers' daily diets were determined using multiple 24-hour recalls, while blood lead levels were measured with inductively coupled plasma mass spectrometry. Serum prolactin levels were assessed using the electrochemiluminescence immunoassay. For bivariate analysis, we employed the Spearman correlation, Mann-Whitney, and Kruskal-Wallis tests, while for multivariate analysis, we utilized multiple linear regression. RESULTS: The average serum prolactin level of the lactating mothers was 129.19±88.96 ng/mL. Positive correlations were found between serum prolactin levels and breastfeeding frequency (p < 0.001), protein intake (p < 0.001), and calcium intake (p = 0.011) but had negative correlation with blood lead levels (p < 0.001) and vitamin B6 intake (p = 0.003). Additionally, prolactin levels were not significantly associated with maternal age; parity; intake of calories, vitamin D, vitamin E, zinc, folic acid, magnesium, or iron; infant age; or infant sex. CONCLUSIONS: Breastfeeding frequency had a stronger positive relationship with serum prolactin levels than protein and calcium intake. However, lead exposure was associated with reduced serum prolactin levels during lactation. Consequently, specific interventions from policymakers are necessary to manage breastfeeding in mothers exposed to lead.

Communities of oil palm flower-visiting insects: investigating the covariation of Elaeidobius kamerunicus and other dominant species.

Insects visit flowers not only to forage for nectar or pollen but also to search for hosts or prey, and to look for suitable habitats for breeding sites. In oil palm flowers, it has been documented that not all flower-visiting insects are pollinators, but some insects are recognized as predators, parasitoids or saprophages, which may affect the abundance and persistence of the weevil pollinating oil palm, Elaeidobius kamerunicus. We studied the community of oil palm flower-visiting insects and investigated the covariation between the abundance E. kamerunicus and that of other dominant species. Ecological research was conducted in oil palm plantations with different tree ages in Central Borneo. Our results found that tree age and flower type of oil palm did not influence the abundance and species richness of flower-visiting insects, but significantly affected their species composition. There was a significant positive relationship between the abundance of E. kamerunicus and the fly Scaptodrosophila sp, indicating that these species covariate in oil palm flowers. These findings suggest that understanding the covariation between E. kamerunicus and Scaptodrosophila sp may help develop the conservation strategies for E. kamerunicus to support the sustainable production of oil palm.

Different levels of IL-1α, IL-6, TNF-α, NF-κB and PPAR-γ in monocyte cultures exposed by plasma preeclampsia and normotensive pregnancy.

OBJECTIVE: To determine different levels of proinflammatory cytokines IL-1α, IL-6, TNF-α, nuclear NF-κB p50 and PPAR-γ in monocyte cultures exposed to normotensive pregnancy plasma compared with those exposed to preeclamptic plasma. Study design The study involved primigravidae with preeclampsia (12) and normotensive pregnancy (12) in which their blood plasma was given to monocyte cultures from isolated PBMC of healthy and non-pregnant women. They were divided into 2 groups, the first group was incubated for 24h and the second one was incubated for 48h (step 1). The levels of IL-1α, IL-6, TNF-α, and nuclear NF-κB p50 as well as PPAR-γ of both groups were subsequently measured and compared (step 2). Data were analyzed to determine the differences and interaction between both treatment groups using one-way ANOVA. RESULTS: There was a significantly different level (p-value <0.05) of IL-1α in monocyte cultures incubated for 24h compared with those incubated for 48h, as shown in step 1 of the study. Meanwhile, step 2 of the study found significantly different levels of IL-1α, IL-6, TNF-α, and NF-κB p50 in monocyte cultures exposed to preeclamptic plasma compared with those exposed to normotensive pregnancy, in which the latter showed higher levels. Both groups also showed decreased levels of PPARγ, in which monocyte culture exposed to severe preeclamptic plasma (p value <0.05). CONCLUSION: Preeclamptic plasma significantly increased levels of proinflammatory cytokines IL-1a, IL-6, and TNF-a in monocyte cultures. This condition was consistent with the increasing of NF-κB p50 and decreasing of PPARγ.