1,384 research outputs found
Reconstructive nature of temporal memory for movie scenes
Remembering when events took place is a key component of episodic memory. Using a sensitive behavioral measure, the present study investigates whether spontaneous event segmentation and script-based prior knowledge affect memory for the time of movie scenes. In three experiments, different groups of participants were asked to indicate when short video clips extracted from a previously encoded movie occurred on a horizontal timeline that represented the video duration. When participants encoded the entire movie, they were more precise at judging the temporal occurrence of clips extracted from the beginning and the end of the film compared to its middle part, but also at judging clips that were closer to event boundaries. Removing the final part of the movie from the encoding session resulted in a systematic bias in memory for time. Specifically, participants increasingly underestimated the time of occurrence of the video clips as a function of their proximity to the missing part of the movie. An additional experiment indicated that such an underestimation effect generalizes to different audio-visual material and does not necessarily reflect poor temporal memory. By showing that memories are moved in time to make room for missing information, the present study demonstrates that narrative time can be adapted to fit a standard template regardless of what has been effectively encoded, in line with reconstructive theories of memory
Inclusive Chemical Characterization of Tourmaline: Mossbauer Study of Fe Valence and Site Occupancy
We report here the results of a series of inclusive chemical characterizations, including all elements except oxygen, for a suite of 54 tourmaline samples. A combination of analytical techniques was used to analyze for major and light elements (electron microprobe), Fe3+ and Fe2+ (Mossbauer spectroscopy), H (U extraction), and B, Li, and F (ion microprobe, or SIMS). The B content of the tourmalines studied ranges from 2.86 to 3.26 B per formula unit (pfu) with 31 anions; excess boron is believed to reside in the Si site. Li ranges from 0.0 to 1.44 Li pfu and F contents are 0.0-0.91 pfu. H contents range from nearly anhydrous up to 3.76 H pfu and do not correlate simply with Fe3+ content. Mossbauer results show that tourmaline exhibits the entire range of Fe3+/Sigma Fe from 0.0-1.0. Fe2+ is represented in the spectra by three doublets, with occupancy in at least three distinct types of Y sites (with different types of nearest and next nearest neighbors). Fe3+ was found in 26 of the 54 samples studied. Although Mossbauer data do not allow the distinction between Fe-[Y](3+) and Fe-[Z](3+) site occupancies to be made, XRD data on these samples suggest that the majority of Fe3+ is also in Y. Of the samples studied, Fe-[4](3+) occurs in nine; five of those were either olenite or uvite with extensive Na substitution. A mixed valence doublet corresponding to delocalized electrons shared between adjacent octahedra was observed in 14 of the samples studied. Projection pursuit regression analysis shows that distribution of Fe among doublets is a function (albeit a complex one) of bulk composition of the tourmaline and supports the interpretation of doublets representing different populations of neighbors. Variations in Fe3+/Fe2+ ratio cannot be directly related to variations in charge in any single site of the structure. Fe3+/Fe2+ ratio is probably controlled by the prevailing oxidation state in the bull; rock assemblage, rather than by any particular crystal chemical substitution
Impact of previous lumbar spine surgery on total hip arthroplasty and vice versa: How long should we be concerned about mechanical failure?
Introduction: This registry study aims to assess the prevalence and demographic characteristics of patients with lumbar spine (LS) surgical procedures who undergo total hip arthroplasty (THA), to compare the long-term survival and causes of failure of THA in patients who previously underwent LS fusion and non-fusion surgical procedures, and to evaluate the risk of undergoing a revision LS surgery after THA. Materials and methods: Patients who underwent LS surgery followed by THA were identified by cross-referencing data from the Orthopedic Prosthetic Implants Registry and the Regional Hospital Discharge Database. Three groups of THA patients were identified: patients who underwent previous lumbar surgery with fusion (LS fusion-THA), without fusion (LS non-fusion-THA), and a control group with only THA (No LS surgery–THA). Demographic data, THA survival, number and causes of failure, and data on revision procedures on THA and LS were collected. Results: Of the total of 79,984 THA, 2.2% of patients had a history of LS procedures. THA only patients showed better results, while patients in the LS fusion-THA group had worse implant survival at 5-year follow-up. In the LS fusion-THA and LS non-fusion-THA, mechanical THA failures were more frequent in the first two years after implantation. There were no differences between groups regarding the risk of undergoing LS revision surgery. Conclusions: LS surgery negatively affects THA survivorship. In patients who previously underwent LS fusion and non-fusion surgical procedures, most THA failure occurs in the first two years after implant. The study contributes to the understanding of the relationship between the hip and the LS and provides useful guidance for clinical practice
Tight Regulation of Mechanotransducer Proteins Distinguishes the Response of Adult Multipotent Mesenchymal Cells on PBCE-Derivative Polymer Films with Different Hydrophilicity and Stiffness
: Mechanotransduction is a molecular process by which cells translate physical stimuli exerted by the external environment into biochemical pathways to orchestrate the cellular shape and function. Even with the advancements in the field, the molecular events leading to the signal cascade are still unclear. The current biotechnology of tissue engineering offers the opportunity to study in vitro the effect of the physical stimuli exerted by biomaterial on stem cells and the mechanotransduction pathway involved in the process. Here, we cultured multipotent human mesenchymal/stromal cells (hMSCs) isolated from bone marrow (hBM-MSCs) and adipose tissue (hASCs) on films of poly(butylene 1,4-cyclohexane dicarboxylate) (PBCE) and a PBCE-based copolymer containing 50 mol% of butylene diglycolate co-units (BDG50), to intentionally tune the surface hydrophilicity and the stiffness (PBCE = 560 Mpa; BDG50 = 94 MPa). We demonstrated the activated distinctive mechanotransduction pathways, resulting in the acquisition of an elongated shape in hBM-MSCs on the BDG50 film and in maintaining the canonical morphology on the PBCE film. Notably, hASCs acquired a new, elongated morphology on both the PBCE and BDG50 films. We found that these events were mainly due to the differences in the expression of Cofilin1, Vimentin, Filamin A, and Talin, which established highly sensitive machinery by which, rather than hASCs, hBM-MSCs distinguished PBCE from BDG50 films
High-performance sustainable active packaging from poly(hexamethylene furanoate) and bark extracts
The development of sustainable high-performance polymeric formulations, possibly showing multifunctional characteristics, is of key importance to produce materials in line with the circular economy agenda. This work focuses on the preparation of fully biomass-derived blends from furan-based polyester and natural extracts to yield an innovative packaging system. Terpenoids and suberin monomers are isolated from largely available waste biomass, namely, birch bark, through simple and straightforward methodologies and mixed with poly(hexamethylene furanoate) (PHF). The physicomechanical properties of the blends evidence a modulation of the surface hydrophobicity together with a significant increase in flexibility and toughness owing to the dual function exerted by the extracts, which act both as plasticizing agents and cross-linking molecules due to the formation of weak interactions, such as hydrogen bonding, with the macromolecular chains of PHF. The evaluation of the functional properties highlights that the excellent gas barrier characteristics of PHF are not just preserved; rather, a substantial increase of the CO2/O-2 permselectivity ratio is measured because of the presence of an increased concentration of disclinations that favor the diffusion of CO2. Lastly, the addition of natural extracts allows for the implementation of antioxidant and antibacterial features otherwise absent in the pristine polymer
In vitro antileishmanial activity of trans-stilbene and terphenyl compounds
Leishmaniasis are globally widespread parasitic diseases which often leads to death if left untreated. Currently available drugs present different drawbacks, so there is an urgent need to develop new, safe and cost-effective drugs against leishmaniasis. In this study we tested a small library of trans-stilbene and terphenyl derivatives against promastigote, amastigotes and intramacrophage amastigote forms of Leishmania infantum. Two compounds of the series, the trans-stilbene 3 and the terphenyl 11, presented the best activity and safety profiles. Terphenyl 11 showed a leshmanicidal activity higher than pentostam and the ability to induce apoptosis selectively in Leishmania infantum while saving macrophages and primary epithelial cells. Our data indicate that terphenyl compounds, as well as stilbenes, are endowed with leishmanicidal activity, showing potential for further studies in the context of leishmanial therapy
Early detection of poor glycemic control in patients with diabetes mellitus in sub-Saharan Africa: a cohort study in Mozambique
Introduction: WHO estimates 422 million cases of diabetes mellitus worldwide. Mozambique has the second-highest mortality related to DM in the African region. Objectives of the present study are to provide data about a DM care service in Mozambique and to evaluate early outcomes of treatment. Methods: The new patients diagnosed with DM in a two-years period in a health centre in Maputo (Mozambique) were included in a retrospective cohort study. Fasting blood glucose (FBG), waist circumference (WC) and BMI were collected at baseline and after three months. Results: 188 patients were enrolled. Median BMI, WC and FBG at baseline were respectively 28 kg/m2(Inter Quartile Range [IQR]23.4-31.8), 98cm (IQR 87-105) and 209mg/dL (IQR 143-295). A non-pharmacological intervention was prescribed for six patients, while 182 patients received metformin 500 mg b.i.d. FBG was significantly reduced at control (226[±103.7]mg/dL vs 186[±93.2]mg/dL, p<0.000); however, glycemic control was reached in 74 patients (39.4%); not controlled patients changed regimen. Elderly patients had a higher glycemic control (adjusted Odds Ratio 2.50, 95% CI 1.11-5.06, p=0.002). Conclusion: Strategies for early detection of scarce glycemic control are feasible in Mozambique and could lead to prompt regimen switch; an invasive therapeutic approach could be preferable in selected cases to achieve control
Aclees Cf. Sp. Foveatus (Coleoptera Curculionidae), an exotic pest of ficus carica in Italy : a sustainable approach to defence based on aluminosilicate minerals as host plant masking solids
The exceptionally frequent entries of alien pest are a major source of concern for the farmers who have to protect their crops from unknown insects, often without natural enemies in the new areas. A new pest belonging to the Molytinae family (Coleoptera: Curculionidae), tribe Hylobiini, reported as Aclees sp. cf. foveatus Voss, was recently introduced in Italy. The species is responsible for severe damages in many Italian fig nurseries and orchards, particularly in the Italian Central Northern regions, i.e. Tuscany, Ligury and Latium. Currently, no active ingredients are registered against this insect on fig crops. An innovative and eco-friendly approach for controlling this exotic weevil infestation was investigated, by using montmorillonite-based clays, either in their native state or containing copper(II) species, and clinoptilolite zeolites, in order to check the perception of the adults\u2019 weevil towards the different solid materials and, subsequently, to evaluate the capability of these innovative products to act as masking agent with respect to the host plant and/or as repellent upon contact. The formulations containing copper(II)-exchanged clay and clinoptilolite zeolite showed preliminary promising results in terms of efficacy and environmental sustainability
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