Low-Fat Diets May Prevent Weight Gain in Sedentary Women: Prospective Observations From the Population Study of Women in Gothenburg,Sweden

The Population Study of Women in Gothenburg, Sweden is an ongoing prospective study of female residents who were recruited from the local registry in 1968–1969 when they were 38–60 years old. The data presented here were collected from 361 healthy women who underwent a baseline physical examination including a supplementary dietary history interview and returned for a second general health examination 6 years later. This report identifies a subgroup of 57 women who were sedentary during their leisure time and appear to have been particularly susceptible to gaining weight as a function of the fat content of their diets. Specifically, longitudinal analysis of body weights in the whole sample revealed a statistical interaction between leisure-time physical activity and habitual dietary fat intake (energy-%), as reported at the baseline examination, in the prediction of subsequent weight change. Further stratified analysis suggested that weight changes were significantly dependent on dietary fat intake among the sedentary women only. High energy intake also predicted weight gain in the sedentary group, although the predictive value for a high-fat diet was of marginal significance after adjusting for total energy consumption. These results suggest that sedentary recreational activity plus a low-fat diet may have a combined contribution to weight change that is not equivalent to the sum of the separate effects. Such a synergy between two modifiable lifestyle factors seems highly relevant for prevention of obesity.     

Scale dependent effects of native prey diversity,prey biomass and natural disturbance on the invasion success of an exotic predator

There is growing support for the general notion that the drivers of invasion success often shift from biotic to abiotic factors with increasing spatial scale. Most of this research, however, has been conducted on a single trophic level; i.e. it has primarily looked at how the diversity of native competitors may influence invasion success. Less attention has been paid to understanding how native prey diversity may influence the invasion success of exotic predators and whether such biotic factors are scale-dependent. We used a hierarchical spatial survey of 17 stream communities to test whether native prey diversity, along with native prey biomass, algal resource abundance and annual stream discharge, influenced the abundance of an exotic crayfish predator, and whether the importance of these factors were scale-dependent. We used a hierarchical generalized linear model to evaluate the influence of these community and stream characteristics on exotic crayfish abundance at both the transect scale (1 m²) and the stream scale (400 m²). Our results indicated that at the stream scale, high stream discharge significantly limited invader abundance. However, at the smaller transect scale, native prey biomass was a significant driver of invasion success and positively correlated with invader abundance. We suggest that our results add to the emerging pattern that abiotic processes are stronger determinants of invasion success at large spatial scales, whereas biotic processes become more important with decreasing spatial scale. However, for predator invasions, prey biomass, not prey diversity may be a more important for driver of invasion success at small spatial scales.     

Complex patterns of dopamine‐related gene expression in the ventral tegmental area of male zebra finches relate to dyadic interactions with long‐term female partners

Dopaminergic projections from the ventral tegmental area (VTA) to multiple efferent targets are implicated in pair bonding, yet the role of the VTA in the maintenance of long‐term pair bonds is not well characterized. Complex interactions between numerous neuromodulators modify activity in the VTA, suggesting that individual differences in patterns of gene expression in this region may explain individual differences in long‐term social interactions in bonded pairs. To test this hypothesis we used RNA‐seq to measure expression of over 8000 annotated genes in male zebra finches in established male‐female pairs. Weighted gene co‐expression network analysis identified a gene module that contained numerous dopamine‐related genes with TH found to be the most connected gene of the module. Genes in this module related to male agonistic behaviors as well as bonding‐related behaviors produced by female partners. Unsupervised learning approaches identified two groups of males that differed with respect to expression of numerous genes. Enrichment analyses showed that many dopamine‐related genes and modulators differed between these groups, including dopamine receptors, synthetic and degradative enzymes, the avian dopamine transporter and several GABA‐ and glutamate‐related genes. Many of the bonding‐related behaviors closely associated with VTA gene expression in the two male groups were produced by the male's partner, rather than the male himself. Collectively, results highlight numerous candidate genes in the VTA that can be explored in future studies and raise the possibility that the molecular/genetic organization of the VTA may be strongly shaped by a social partner and/or the strength of the pair bond.     

Phosphoproteomics identifies microglial Siglec‐F inflammatory response during neurodegeneration

Alzheimer’s disease (AD) is characterized by the appearance of amyloid‐β plaques, neurofibrillary tangles, and inflammation in brain regions involved in memory. Using mass spectrometry, we have quantified the phosphoproteome of the CK‐p25, 5XFAD, and Tau P301S mouse models of neurodegeneration. We identified a shared response involving Siglec‐F which was upregulated on a subset of reactive microglia. The human paralog Siglec‐8 was also upregulated on microglia in AD. Siglec‐F and Siglec‐8 were upregulated following microglial activation with interferon gamma (IFNγ) in BV‐2 cell line and human stem cell‐derived microglia models. Siglec‐F overexpression activates an endocytic and pyroptotic inflammatory response in BV‐2 cells, dependent on its sialic acid substrates and immunoreceptor tyrosine‐based inhibition motif (ITIM) phosphorylation sites. Related human Siglecs induced a similar response in BV‐2 cells. Collectively, our results point to an important role for mouse Siglec‐F and human Siglec‐8 in regulating microglial activation during neurodegeneration.     

Preventive antibiotic treatment of calves: emergence of dysbiosis causing propagation of obese state-associated and mobile multidrug resistance-carrying bacteria

In agriculture, antibiotics are used for the treatment and prevention of livestock disease. Antibiotics perturb the bacterial gut composition but the extent of these changes and potential consequences for animal and human health is still debated. Six calves were housed in a controlled environment. Three animals received an injection of the antibiotic florfenicol (Nuflor), and three received no treatment. Faecal samples were collected at 0, 3 and 7 days, and bacterial communities were profiled to assess the impact of a therapy on the gut microbiota. Phylogenetic analysis (16S-rDNA) established that at day 7, antibiotic-treated microbiota showed a 10-fold increase in facultative anaerobic Escherichia spp, a signature of imbalanced microbiota, dysbiosis. The antibiotic resistome showed a high background of antibiotic resistance genes, which did not significantly change in response to florfenicol. However, the maintenance of Escherichia coli plasmid-encoded quinolone, oqxB and propagation of mcr-2, and colistin resistance genes were observed and confirmed by Sanger sequencing. The microbiota of treated animals was enriched with energy harvesting bacteria, common to obese microbial communities. We propose that antibiotic treatment of healthy animals leads to unbalanced, disease- and obese-related microbiota that promotes growth of E. coli carrying resistance genes on mobile elements, potentially increasing the risk of transmission of antibiotic resistant bacteria to humans.     

GPI7-mediated glycosylphosphatidylinositol anchoring regulates appressorial penetration and immune evasion during infection of Magnaporthe oryzae

Glycosylphosphatidylinositol (GPI) anchoring plays key roles in many biological processes by targeting proteins to the cell wall; however, its roles are largely unknown in plant pathogenic fungi. Here, we reveal the roles of the GPI anchoring in Magnaporthe oryzae during plant infection. The GPI-anchored proteins were found to highly accumulate in appressoria and invasive hyphae. Disruption of GPI7, a GPI anchor-pathway gene, led to a significant reduction in virulence. The Δgpi7 mutant showed significant defects in penetration and invasive growth. This mutant also displayed defects of the cell wall architecture, suggesting GPI7 is required for cell wall biogenesis. Removal of GPI-anchored proteins in the wild-type strain by hydrofluoric acid (HF) pyridine treatment exposed both the chitin and β-1,3-glucans to the host immune system. Exposure of the chitin and β-1,3-glucans was also observed in the Δgpi7 mutant, indicating GPI-anchored proteins are required for immune evasion. The GPI anchoring can regulate subcellular localization of the Gel proteins in the cell wall for appressorial penetration and abundance of which for invasive growth. Our results indicate the GPI anchoring facilitates the penetration of M. oryzae into host cells by affecting the cell wall integrity and the evasion of host immune recognition.     

Thinking systemically about ecological interventions: what do system archetypes teach us?

To address the need for more holistic approaches to ecological management and restoration, we examine ecosystem interventions through the lens of systems thinking and in reference to systems archetypes, as developed in relation to organizational management in the business world. Systems thinking is a holistic approach to analysis that focuses on how a system's constituent parts interrelate and how systems work over time and within the context of larger systems. Systems archetypes represent patterns of behavior that have been observed repeatedly. These archetypes help relate commonly observed responses to environmental problems with their effect on important feedback processes to better anticipate connections between actions and results. They highlight situations where perceived solutions actually result in worse or unintended consequences, and where changing goals may be either appropriate or inappropriate. The archetypes can be applied to practical examples, and can provide guidance to help make appropriate intervention decisions in similar circumstances. Their use requires stepping back from immediately obvious management decisions and taking a more systemic view of the situation. A catalog of archetypes that describe common patterns of systems behavior may inform management by helping to diagnose system dynamics earlier and identifying interactions among them.