225 research outputs found
Scarcity and consumers’ credit choices
We study the effect of scarcity on decision making by low income Swedes. We exploit the random assignment of welfare payments to study their borrowing decisions within the pawn and mainstream credit market. We document that higher educated borrowers borrow less frequently and choose lower loan to value ratios when their budget constraints are exogenously tighter. In contrast, low-educated borrowers do not respond to temporary elevated levels of scarcity. This lack of response translates into a significantly higher probability to default and an 11.6% increase in borrowing cost. We show that a difference in access to liquidity and/or buffer stocks cannot explain our results. Instead a framework, where the awareness of self-control problems is positively correlated with education can explain that high-educated consumers choose a lower LTV as a commitment device to increase their likelihood to repay. Analogously, low-educated with less awareness of their future self-control problems, do not tie themselves to the mast and thus ignore the consequences of their credit decisions when focusing on solving acute liquidity problems. Our findings highlight that increased levels of scarcity risk reinforcing the conditions of poverty through overborrowing
An atomic hydrogen beam to test ASACUSA's apparatus for antihydrogen spectroscopy
The ASACUSA collaboration aims to measure the ground state hyperfine
splitting (GS-HFS) of antihydrogen, the antimatter pendant to atomic hydrogen.
Comparisons of the corresponding transitions in those two systems will provide
sensitive tests of the CPT symmetry, the combination of the three discrete
symmetries charge conjugation, parity, and time reversal. For offline tests of
the GS-HFS spectroscopy apparatus we constructed a source of cold polarised
atomic hydrogen. In these proceedings we report the successful observation of
the hyperfine structure transitions of atomic hydrogen with our apparatus in
the earth's magnetic field.Comment: 8 pages, 4 figures, proceedings for conference EXA 2014 (Exotic Atoms
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Spatial consistency in drivers of population dynamics of a declining migratory bird
1. Many migratory species are in decline across their geographical ranges. Single-population studies can provide important insights into drivers at a local scale, but effective conservation requires multi-population perspectives. This is challenging because relevant data are often hard to consolidate, and state-of- the-art analytical tools are typically tailored to specific datasets. 2. We capitalized on a recent data harmonization initiative (SPI-Birds) and linked it to a generalized modelling framework to identify the demographic and environmental drivers of large-scale population decline in migratory pied flycatchers (Ficedula hypoleuca) breeding across Britain. 3. We implemented a generalized integrated population model (IPM) to estimate age-specific vital rates, including their dependency on environmental conditions, and total and breeding population size of pied flycatchers using long-term (34–64 years) monitoring data from seven locations representative of the British breeding range. We then quantified the relative contributions of different vital rates and population structure to changes in short-and long-term population growth rate using transient life table response experiments (LTREs). 4. Substantial covariation in population sizes across breeding locations suggested that change was the result of large-scale drivers. This was supported by LTRE analyses, which attributed past changes in short-term population growth rates and long-term population trends primarily to variation in annual survival and dispersal dynamics, which largely act during migration and/or nonbreeding season. Contributions of variation in local reproductive parameters were small in comparison, despite sensitivity to local temperature and rainfall within the breeding period. 5. We show that both short-and long-term population changes of British breeding pied flycatchers are likely linked to factors acting during migration and in nonbreeding areas, where future research should be prioritized. We illustrate the potential of multi-population analyses for informing management at (inter)national scales and highlight the importance of data standardization, generalized and accessible analytical tools, and reproducible workflows to achieve them. annual survival, comparative analysis, environmental effects, full annual cycle, integrated population model, LTRE, multi-population, pied flycatcherpublishedVersio
Signal, Not Poison—Screening Mint Essential Oils for Weed Control Leads to Horsemint
Weed control tries to suppress competitors for a crop and often relies on differential intoxication, making use of differences in uptake, development, or metabolism. We explored the possibility of using natural signals to shift competition in favour of the crop. Using the competitive horsemint (Mentha longifolia) as a paradigm, we showed that essential oils from certain mint species suppress the seedling development of different target species in a specific and efficient manner. The specificity concerned both the donor and the receptor. We demonstrated further that the effect of horsemint oil was specific for actin filaments, and not for microtubules. Since the elimination of actin will impair auxin transport, which is essential for root regeneration in vegetatively propagating weeds, we tested the efficacy of horsemint essential oil in combination with a slow-release carrier against field bindweed (Convolvulus arvensis), a pertinent weed in organic cereal production. We observed that the development of this weed can be specifically blocked, especially if the carrier is worked into the soil. We propose that allelopathic interactions, often relying on manipulative chemical signalling, harbour significant potential for organic weed control
Interfacial photochemistry of biogenic surfactants: a major source of abiotic volatile organic compounds
International audience15 Films of biogenic compounds exposed to the atmosphere are ubiquitously found on surfaces of cloud droplets, aerosol particles, buildings, plants, soils, and the ocean. These air/water interfaces host countless amphiphilic compounds concentrated there with respect to bulk water, leading to a unique chemical environment. Here, photochemical processes at the air/water interface of biofilm-containing solutions were studied, demonstrating abiotic VOC production from authentic biogenic 20 surfactants under ambient conditions. Using a combination of online-APCI-HRMS and PTR-ToF-MS, unsaturated and functionalized VOCs were identified and quantified, giving emission fluxes comparable to previous field and laboratory observations. Interestingly, VOC fluxes increased with the decay of microbial cells in the samples, indicating that cell lysis due to cell death was the main source for surfactants, and VOC production. In particular, irradiation of samples containing solely 25 biofilm cells without matrix components exhibited the strongest VOC production upon irradiation. In agreement with previous studies, LC-MS measurements of the liquid phase suggested the presence of fatty acids and known photosensitizers, possibly inducing the observed VOC production via peroxy-radical chemistry. Up to now such VOC emissions were directly accounted to high biological activity in surface waters. However, the obtained results suggest that abiotic photochemistry can 30 lead to similar emissions into the atmosphere, especially in less biologically-active regions. Furthermore, chamber experiments suggested that oxidation (O 3 /OH-radicals) of the photochemically-produced VOCs leads to aerosol formation and growth, possibly affectin
Heparin-based, injectable microcarriers for controlled delivery of interleukin-13 to the brain
Interleukin-13 (IL-13) drives cells of myeloid origin towards a more anti-inflammatory phenotype, but delivery to the brain remains problematic. Herein, we show that heparin-based cryogel microcarriers load high amounts of IL-13, releasing it slowly. Intra-striatal injection of loaded microcarriers caused local up-regulation of ARG1 in myeloid cells for pro-regenerative immunomodulation in the brain
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Heparin-based, injectable microcarriers for controlled delivery of interleukin-13 to the brain
Interleukin-13 (IL-13) drives cells of myeloid origin towards a more anti-inflammatory phenotype, but delivery to the brain remains problematic. Herein, we show that heparin-based cryogel microcarriers load high amounts of IL-13, releasing it slowly. Intra-striatal injection of loaded microcarriers caused local up-regulation of ARG1 in myeloid cells for pro-regenerative immunomodulation in the brain. © 2020 The Royal Society of Chemistry
Mutual stimulatory signaling between human myogenic cells and rat cerebellar neurons
Abstract Insight into the bidirectional signaling between primary human myogenic cells and neurons is lacking. For this purpose, human myogenic cells were derived from the semitendinosus and gracilis muscles of five healthy individuals and co‐cultured with cerebellar granule neurons from two litters of 7‐day‐old Wistar rat pups, in muscle medium or neural medium, alongside monocultures of myogenic cells or neurons. RT‐PCR was performed to determine human mRNA levels of GAPDH, Ki67, myogenin, and MUSK, and the acetylcholine receptor subtypes CHRNA1, CHRNB1, CHRNG, CHRND, and CHRNE, and rat mRNA levels of GAPDH, Fth1, Rack1, vimentin, Cdh13, and Ppp1r1a. Immunocytochemistry was used to evaluate neurite outgrowth (GAP43) in the presence and absence of myogenic cells. Co‐culture with primary neurons lead to higher myogenic cell gene expression levels of GAPDH, myogenin, MUSK, CHRNA1, CHRNG, and CHRND, compared to myogenic cells cultured alone. It appeared that neurons preferentially attached to myotubes and that neurite outgrowth was enhanced when neurons were cultured with myogenic cells compared to monoculture. In neural medium, rat mRNA levels of GAPDH, vimentin, Cdh13, and Ppp1r1a were greater in co‐culture, versus monoculture, whereas in muscle medium co‐culture lead to lower levels of Fth1, Rack1, vimentin, and Cdh13 than monoculture. These findings demonstrate mutually beneficial stimulatory signaling between rat cerebellar granule neurons and human myogenic cells, providing support for an active role for both the neuron and the muscle cell in stimulating neurite growth and myogenesis. Bidirectional muscle nerve signaling
USING ESDM 12 HOURS PER WEEK IN CHILDREN WITH AUTISM SPECTRUM DISORDER: FEASIBILITY AND RESULTS OF AN OBSERVATIONAL STUDY
Background: Early intervention for Autism Spectrum Disorder (ASD) in France is heterogeneous and poorly evaluated to date. Early Start Denver Model (ESDM) is a developmental and behavioral model ofintervention for toddlers with ASD which has already shown very interesting outcomes on the development of children with ASD in various studies with different settings. However, it is not possible with the current research to agree on the best setting. Thus, we implemented an ESDM program according to our context where children are often pre-schooling early from 30 months old. This therapy was applied by a multidisciplinary team working in close collaboration with parents and other partners.
Subjects and methods: A prospective observational study including 19 toddlers with ASD was conducted. We evaluated improvement on the cognitive level of toddlers with ASD receiving therapist-delivered ESDM intervention for 12 hours per week.
Results: Significant improvements in verbal and nonverbal cognitive skills at the Mullen Scale of Early Learning were obtained after 10 months of intervention in our sample. The largest improvement was in receptive language development quotient with a mean improvement of 19.6 points. We also observed promising outcomes in daily adaptive behavior, with a slight improvement in communication at the Vineland Adaptive Behavioral Scale. These outcomes, when compared to the conclusions of previous studies, are leading us to the need for a therapy duration beyond 10 months.
Conclusions: Our outcomes were very encouraging even with lowcognitive and nonverbal children. These outcomes may be confirmed in a multicenter randomized controlled trial that is ongoing
Assessing immunogenicity barriers of the HIV-1 envelope trimer
Understanding the balance between epitope shielding and accessibility on HIV-1 envelope (Env) trimers is essential to guide immunogen selection for broadly neutralizing antibody (bnAb) based vaccines. To investigate the antigenic space of Env immunogens, we created a strategy based on synthetic, high diversity, Designed Ankyrin Repeat Protein (DARPin) libraries. We show that DARPin Antigenicity Analysis (DANA), a purely in vitro screening tool, has the capability to extrapolate relevant information of antigenic properties of Env immunogens. DANA screens of stabilized, soluble Env trimers revealed that stronger trimer stabilization led to the selection of highly mutated DARPins with length variations and framework mutations mirroring observations made for bnAbs. By mimicking heterotypic prime-boost immunization regimens, DANA may be used to select immunogen combinations that favor the selection of trimer-reactive binders. This positions DANA as a versatile strategy for distilling fundamental antigenic features of immunogens, complementary to preclinical immunogenicity testing
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