529 research outputs found

    Combining social sciences, geoscience and archaeology to understand societal collapse

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    Despite its apparently obvious conclusion that adverse environmental conditions must produce economic and institutional crises, the "collapse archaeology" literature has been criticized for its lack of a formal theory, a credible measurement strategy and a proper understanding of the roles of environmental shocks. To tackle this issue, we propose to combine a time inconsistency theory of state formation and evolutiondi.e., state-building, institutional proxies based on this model and highly granular simulated climate data. To clarify our proposal, we apply it to the study of state-building in Bronze Age Mesopotamia, and we show that moderate droughts shaped these economies directly via deteriorated production conditions as well as indirectly via institutional resilience.& COPY; 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

    Subcutaneous adipose tissue classification

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    The developments in the technologies based on the use of autologous adipose tissue attracted attention to minor depots as possible sampling areas. Some of those depots have never been studied in detail. The present study was performed on subcutaneous adipose depots sampled in different areas with the aim of explaining their morphology, particularly as far as regards stem niches. The results demonstrated that three different types of white adipose tissue (WAT) can be differentiated on the basis of structural and ultrastructural features: deposit WAT (dWAT), structural WAT (sWAT) and fibrous WAT (fWAT). dWAT can be found essentially in large fatty depots in the abdominal area (periumbilical). In the dWAT, cells are tightly packed and linked by a weak net of isolated collagen fibers. Collagenic components are very poor, cells are large and few blood vessels are present. The deep portion appears more fibrous then the superficial one. The microcirculation is formed by thin walled capillaries with rare stem niches. Reinforcement pericyte elements are rarely evident. The sWAT is more stromal; it is located in some areas in the limbs and in the hips. The stroma is fairly well represented, with a good vascularity and adequate staminality. Cells are wrapped by a basket of collagen fibers. The fatty depots of the knees and of the trochanteric areas have quite loose meshes. The fWAT has a noteworthy fibrous component and can be found in areas where a severe mechanic stress occurs. Adipocytes have an individual thick fibrous shell. In conclusion, the present study demonstrates evident differences among subcutaneous WAT deposits, thus suggesting that in regenerative procedures based on autologous adipose tissues the sampling area should not be randomly chosen, but it should be oriented by evidence based evaluations. The structural peculiarities of the sWAT, and particularly of its microcirculation, suggest that it could represent a privileged source for regenerative procedures based on autologous adipose tissues

    The trochanteric fat pad

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    Technological developments based on the use of autologous white adipose tissue (WAT) attracted attention to minor fat depots as possible sources of adipose tissue. In plastic surgery, the trochanteric fatty pad is one of the most used WAT depots for its location and organoleptic characteristics that make it particularly suitable for reconstructive procedures. Despite its wide use in clinic, the structure of this depot has never been studied in detail and it is not known if structural differences exist among trochanteric fat and other subcutaneous WAT depots. The present study was performed on trochanteric fat pad with the aim to clarify the morphology of its adipocytes, stroma and microcirculation, with particular reference to the stem niches. Histological and ultrastructural studies showed that the main peculiar feature of the trochanteric fat concerns its stromal component, which appears less dense than in the other subcutaneous WATs studied. The intra-parenchymal collagen stroma is poor and the extracellular compartment shows large spaces, filled with electron-light material, in which isolated collagen bundles are present. The adipocytes are wrapped in weak and easily detachable collagen baskets. These connective sheaths are very thin compared to the sheaths in other subcutaneous WAT depots. The capillaries are covered by large, long and thin elements surrounded by an external lamina; these perivascular cells are poor in organelles and mainly contain poly-ribosomes. In conclusion, when compared to other WAT deposits, the trochanteric fatty pad shows structural peculiarities in its stroma and microcirculation suggesting a high regenerative potential. Resistance, dissociability, microvascular weft and high regenerative potential make the trochanteric fatty pad a privileged source for harvesting in autologous WAT-based regenerative procedures

    Spad index for diagnosis of nitrogen status in 'Esmeralda' peach.

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    O objetivo do presente trabalho foi avaliar a viabilidade técnica do índice SPAD no diagnóstico do estado de N em pessegueiros cv. Esmeralda. O experimento, com cinco níveis de N aplicado no solo (0; 40; 80; 120 e 160 kg ha-1 de N na forma de ureia), foi conduzido a campo, em delineamento experimental de blocos ao acaso, com quatro repetições. Durante os anos de 2014, 2015, 2016 e 2017, realizaram-se leituras com clorofilômetro, modelo Minolta SPAD-502, na parte mediana da folha, em 40 folhas por parcela. A determinação do teor foliar de N foi realizada em Analisador ElementarCHN-S. O índice SPAD e o teor de N nas folhas aumentaram de forma linear, de acordo com o aumento das doses de N aplicadas no solo. Houve efeito das doses de N aplicadas no solo sobre o índice SPAD, e os teores foliares de N apresentaram correlação linear positiva com as leituras SPAD (0.652; 0.756; 0.762 e 0.767, p<0.05). O índice SPAD pode ser utilizado no diagnóstico nutricional de N em pessegueiro, quando as leituras são realizadas entre a 13a e a 15a semana após a plena floração. Na faixa compreendida entre 39 e 49, o índice SPAD indica que o N foliar está compreendido na classe ?normal? (33 ? 45 g kg-1) de interpretação agronômica, para os Estados do Rio Grande do Sul e de Santa Catarina, Brasil

    Dark chocolate modulates platelet function with a mechanism mediated by flavan-3-ol metabolites

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    Cocoa is a rich source bioactive compounds, i.e., flavan-3-ols, and its consumption has been associated with several beneficial effects, such as the positive modulation of the hemostasis targeted by the platelet function. However, these phenolic compounds have a very low bioavailability and extensively undergo phase I and II metabolism, with the appearing into the bloodstream of (epi) catechin conjugates and phenyl-g-valerolactones and their conjugates, at different times. The aims of this study were to explore the effect of dark chocolate on platelet function and to investigate the relationship between this interplay and flavan-3-ol derived metabolites. Eighteen healthy male volunteers ingested 50 g of 90% cocoa chocolate within 5 minutes. Blood samples were collected immediately before chocolate ingestion (T0) and 4 hours afterwards (T1). Platelet function analyzer (PFA)-100 closure time was assessed using collagen/adenosine-50-diphosphate (COL/ADP) and collagen/epinephrine (COL/EPI) cartridges. Plasma flavan-3-ol metabolites were identified and quantified by means of liquid chromatography coupled to a triple quadrupole mass spectrometer (UHPLC-ESI-MS/MS). Results evidenced a significant increase of COL/ADP-induced PFA-100 closure time, but not COL/EPI, 4 hours after ingestion of dark chocolate. Total plasma structurally-related (epi)catechin metabolite (SREM) concentration significantly increased at T1, together with 4 out of the 6 detected metabolites. Total phenyl-g-valerolactone concentrations remained unchanged. Spearman correlations evidenced a strong correlation between COL/ADP closure time and SREMs, mainly led by (epi)catechin-sulfate isomers. These data confirm that the potential beneficial effect of dark chocolate on primary hemostasis may be mediated by flavan-3-ol circulating metabolites

    Human Bocavirus Infection in Children with Gastroenteritis, Brazil

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    Human bocavirus (HBoV) was detected in 14 (2%) of 705 fecal specimens from Brazilian children with gastroenteritis. Coinfection with rotavirus, adenovirus, or norovirus was found in 3 (21.4%) HBoV-positive specimens. None of the HBoV-positive patients had respiratory symptoms

    Digital dermoscopic changes during follow-up of de-novo and nevus-associated melanoma: a cohort study

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    Background: Nevus-associated melanoma (NAM) has been regarded as a distinct biological entity from de-novo melanoma (DNM); however, static dermoscopy often fails in differentiating these entities. Digital dermoscopic monitoring allows to identify dynamic changes occurring during follow-up; this may improve diagnostic accuracy and potentially our knowledge on NAM biology. We aimed to define main independent factors associated with NAM diagnosis and those influencing follow-up time in a population of melanomas excised at follow-up. Methods: A cohort of melanomas excised at follow-up was retrospectively and consecutively selected. NAMs and DNMs were compared according to baseline features and main dermoscopic changes occurring during follow-up. Univariate and multivariable logistic and Cox's regression analysis were performed to respectively define factors associated with NAM diagnosis and those influencing the risk for excision. Results: Eighty-six melanomas were enrolled, of which 21 (24.4%) were nevus-associated. During follow-up NAMs mainly underwent atypical network modifications (47.6%), followed by inverse network (28.6%) and dermoscopic island (23.8%) worsening or appearance. DNMs were also mainly characterized by atypical network modifications (47.7%), however, a significant proportion of cases underwent irregular pigmentation/dots/globules or regression changes (29.2%), which were rarely seen among NAMs. Furthermore, both multivariable logistic and Cox's regression analysis demonstrated a significant association between NAM and a longer follow-up. Conclusions: We demonstrated that among melanomas excised at follow-up, different patterns of dermoscopic changes may be found between NAMs and DNMs. This finding, together with the association of NAM with a longer follow-up time, supports the hypothesis of different biological behavior of these two entities

    Online measurement of fluence and position for protontherapy beams

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    Tumour therapy with proton beams has been used for several decades in many centres with very good results in terms of local control and overall survival. Typical pathologies treated with this technique are located in head and neck, eye, prostate and in general at big depths or close to critical organs. The Experimental Physics Department of the University of Turin and the local Section of INFN, in collaboration with INFN Laboratori Nazionali del Sud Catania and Centre de Protontherapie de Orsay Paris, have developed detector systems that allow the measurement of beam position and fluence, obtained in real time during beam delivery. The centre in Catania (CATANA: Centro di AdroTerapia ed Applicazioni Nucleari Avanzate) has been treating patients with eye pathologies since spring 2002 using a superconducting cyclotron accelerating protons up to 62 MeV. This kind of treatments need high-resolution monitor systems and for this reason we have developed a 256-strip segmented ionisation chamber, each strip being 400 μm wide, with a total sensitive area 13 × 13 cm2. The Centre de Protontherapie de Orsay (CPO) has been operational since 1991 and features a synchrocyclotron used for eye and head and neck tumours with proton beams up to 200 MeV. The monitor system has to work on a large surface and for this purpose we have designed a pixel-segmented ionisation chamber, each pixel being 5×5 mm2, for a total active area of 16 × 16 cm2. The results obtained with two prototypes of the pixel and strip chambers demonstrate that the detectors allow the measurement of fluence and centre of gravity as requested by clinical specifications

    Reference miRNAs for colorectal cancer: analysis and verification of current data

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    MicroRNAs (miRNAs) hold great promise in cancer research. The use of appropriate reference miRNAs for normalization of qPCR data is crucial for accurate expression analysis. We present here analysis and verification of current data, proposing a workflow strategy for identification of reference miRNAs in colorectal cancer (CRC). We performed a systematic review of studies aimed to identify stable reference miRNAs in CRC through high-throughput screening. Among the candidate miRNAs selected from the literature we excluded those predicted to target oncogenes or tumor suppressor gene. We then assessed the expression levels of the remaining candidates in exosomes, plasma and tissue samples from CRC patients and healthy controls. The expression stability was evaluated by box-plot, 06Cq analysis, NormFinder and BestKeeper statistical algorithms. The effects of normalisers on the relative quantification of the oncogenic miR-1290 was also assessed. Our results consistently showed that different combinations of miR-520d, miR-1228 and miR-345 provided the most stably expressed reference miRNAs in the three biological matrices. We identified suitable reference miRNAs for future miRNA expression studies in exosomes plasma and tissues CRC samples. We also provided a novel conceptual framework that overcome the need of performing ex novo identification of suitable reference genes in single experimental systems

    Measurement of the Spin-Dependence of the pbar-p Interaction at the AD-Ring

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    We propose to use an internal polarized hydrogen storage cell gas target in the AD ring to determine for the first time the two total spin-dependent pbar-p cross sections sigma_1 and sigma_2 at antiproton beam energies in the range from 50 to 450 MeV. The data obtained are of interest by themselves for the general theory of pbar-p interactions since they will provide a first experimental constraint of the spin-spin dependence of the nucleon-antinucleon potential in the energy range of interest. In addition, measurements of the polarization buildup of stored antiprotons are required to define the optimum parameters of a future, dedicated Antiproton Polarizer Ring (APR), intended to feed a double-polarized asymmetric pbar-p collider with polarized antiprotons. Such a machine has recently been proposed by the PAX collaboration for the new Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt, Germany. The availability of an intense stored beam of polarized antiprotons will provide access to a wealth of single- and double-spin observables, thereby opening a new window on QCD spin physics.Comment: 51 pages, 23 figures, proposal submitted to the SPS committee of CER
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