Coverage, determinants of use and repurposing of long‑lasting insecticidal nets two years after a mass distribution in Lihir Islands, Papua New Guinea: a cross‑sectional study

Background: Universal coverage with long-lasting insecticidal nets (LLINs) is an essential component of malaria control programmes. Three-yearly mass distribution of LLINs in Papua New Guinea (PNG) has been successful in reducing infection transmission since 2009, but malaria prevalence ramped up from 2015 onwards. Although LLIN universal coverage is mostly achieved during these campaigns, it may not be related with net use over time. Uses given to LLINs and non-compliance of this strategy were evaluated. Methods: A knowledge, attitude and practice (KAP) cross-sectional study was conducted in Lihir Islands, PNG, 2–2.5 years after the last LLIN mass distribution campaign. Data on bed net ownership, use and maintenance behaviour was collected using a household questionnaire administered by trained community volunteers. Logistic regression models were used to identify factors associated with owning at least one LLIN and sleeping under a LLIN the previous night. Results: Among 2694 households surveyed, 27.4 % (95 % CI: 25.8–29.2) owned at least one LLIN and 8.7 % (95 % CI: 7.6–9.8) had an adequate LLIN coverage (at least one LLIN for every two people). Out of 13,595 individuals in the surveyed households, 13.6 % (95 % CI: 13.0-–4.2) reported having slept under a LLIN the preceding night. Determinants for sleeping under LLIN included living in a household with adequate LLIN coverage [adjusted OR (aOR) = 5.82 (95 % CI: 3.23–10.49)], household heads knowledge about LLINs [aOR = 16.44 (95 % CI: 8.29–32.58)], and female gender [aOR = 1.92 (95 % CI: 1.53–2.40)] (all p-values < 0.001). LLIN use decreased with older age [aOR = 0.29 (95 % CI: 0.21–0.40) for ≥ 15 year-olds, aOR = 0.38 (95 % CI: 0.27–0.55) for 5–14 year-olds] compared to < 5 year-olds (p-value < 0.001). Knowledge on the use of LLIN was good in 37.0 % of the household heads. Repurposed nets were reported serving as fishing nets (30.4 %), fruits and seedlings protection (26.6 %), covering up food (19.0 %) and bed linen (11.5 %). Conclusions: Two years after mass distribution, LLIN coverage and use in Lihir Islands is extremely low. Three yearly distribution campaigns may not suffice to maintain an acceptable LLIN coverage unless knowledge on maintenance and use is promoted trough educational campaigns

Krüppel-like factor 4 regulates macrophage polarization

Current paradigms suggest that two macrophage subsets, termed M1 and M2, are involved in inflammation and host defense. While the distinct functions of M1 and M2 macrophages have been intensively studied — the former are considered proinflammatory and the latter antiinflammatory — the determinants of their speciation are incompletely understood. Here we report our studies that identify Krüppel-like factor 4 (KLF4) as a critical regulator of macrophage polarization. Macrophage KLF4 expression was robustly induced in M2 macrophages and strongly reduced in M1 macrophages, observations that were recapitulated in human inflammatory paradigms in vivo. Mechanistically, KLF4 was found to cooperate with Stat6 to induce an M2 genetic program and inhibit M1 targets via sequestration of coactivators required for NF-κB activation. KLF4-deficient macrophages demonstrated increased proinflammatory gene expression, enhanced bactericidal activity, and altered metabolism. Furthermore, mice bearing myeloid-specific deletion of KLF4 exhibited delayed wound healing and were predisposed to developing diet-induced obesity, glucose intolerance, and insulin resistance. Collectively, these data identify KLF4 as what we believe to be a novel regulator of macrophage polarization

Structure and dynamics of polymer nanocomposites studied by X-ray and neutron scattering techniques

The structure and dynamics of filler nanoparticles and macromolecules in polymer nanocomposites determine many aspects of macroscopic behavior, which is why these properties have attracted considerable interest in the scientific literature. In this article, recent progress using scattering techniques for the elucidation of structure and dynamics, of both filler nanoparticles and polymer chains, is reviewed. Small-angle X-ray and neutron scattering, more and more combined with direct imaging methods and simulations, are appropriate methods to investigate nanocomposite structure. While they can usually be applied to standard samples for filler structure, chain structure can only be accessed with neutrons and isotopic substitution, under the zero-average contrast condition to match the filler contribution. Quasi-elastic neutron scattering and X-ray photon correlation spectroscopy cover different time scales with spatial resolution in the nanoscale. The former allows studies of polymer motions from atomic or segmental relaxation to reptation of the entire chain in presence of filler, while the latter is increasingly used for investigations of nanoparticle dynamics