Les macrofossiles de charbon de bois enfouis dans le sol sont employés en paléoécologie pour étudier l’histoire écologique des communautés végétales ligneuses. L’approche moderne employant les charbons enfouis dans le sol (pédoanthracologie) s’appuie sur l’identification taxonomique sur la base de l’anatomie du bois à l’aide de guides d’identification et d’une collection d’échantillons de référence (anthracothèque) provenant de la région étudiée. Il n’existe pas encore de collection de référence pour les Landes de Gascogne et leur périphérie. Nous profitons d’une étude pédoanthracologique focalisée sur cette région pour établir une telle collection de 30 échantillons de référence provenant de 29 espèces ligneuses communes dans la région. Nous documentons une approche méthodologique simple et économique pour produire les échantillons...

El objetivo del artículo es dar cuenta del proceso de gramaticalización del pronombre personal tónico usted empleado como el clítico -ste en el castellano del sur del departamento de Amazonas (Perú). De acuerdo con el análisis semántico, morfosintáctico y fonológico, este proceso de gramaticalización ha dado origen a un clítico que aporta el sentido de ‘distanciamiento o formalidad’ entre los interlocutores de un evento discursivo. La conclusión principal reporta que el clítico -ste, producto de la gramaticalización del pronombre usted, caracteriza una variedad del castellano andino norperuano, atestiguado también en las provincias andinas de La Libertad, algunas provincias de Cajamarca y Áncash, y en el Bajo Piura (Andrade, 2016, 2018, 2019).

Many species of chili peppers have overlapping morphological characters and delimitation by visual descriptors in many cases fails to differentiate one species from another. In Peru, there are 413 accessions of native chili pepper and 296 accessions of rocotos conserved in the Germplasm Collections of the National Institute of Agrarian Innovation (INIA), of which five accessions (three species from three locations) were selected for the present metabolomic study. The Discrimination of the three species of native chili peppers and identification of biomarkers was performed using untargeted metabolomic approach based on profiling by UHPLC-HRMS and multivariate data analysis. The samples of fresh chili peppers (whole fruit) from Chincha area were used to construct an OPLS-DA model. To validate the biomarkers (identified 15 biomarkers, mainly flavonoids), an external validation set of the OP...

Study region The upper Amazon River, where the water level measured at the Tamshiyacu station (Peru) shows seasonal variability of seven meters. Study focus Key parameters for the flood recession period (beginning, end and duration of the low-water period, velocity of water falling and rising, and inversions in the direction of stage change known as “repiquete” events) are analyzed for the period 1985–2015, along with their relationship to rainfall integrated in the upper Amazon basin at Tamshiyacu. New hydrological insights the low-water period lasts about four months, beginning, on average, at the end of July and ending in early November. Since the late 1990s, the low-water period has tended to end later, last longer and the flood recession ends more abruptly than it used to. This may be related to the increased frequency of dry days during the austral winter in the central and s...

This paper documents the spatiotemporal evolution of wet‐day and dry‐day frequency (WDF and DDF) in the western Amazon, its relationships with oceanic and atmospheric variability and possible impact on vegetation. WDF and DDF changed significantly during the 1980–2009 period (p < 0.05). An increase in WDF is observed after 1995 over the northern part of the western Amazon (Marañón basin). The average annual value of WDF changed from 22 days/yr before 1995 to 34 days after that date (+55% after 1995). In contrast, DDF increased significantly over the central and southern part of this region (Ucayali basin) after 1986. Average annual DDF was 16.2 days before 1986 and 23.8 days afterward (+47% after 1986). Interannual variability in WDF appears to be modulated by changes in Pacific SST and the Walker cell during the November–March season. This mechanism enhances convective act...

El análisis de datos anuales, estacionales o mensuales de precipitación puede conducir a una interpretación limitada de la distribución espacial y temporal de la lluvia diaria debido a que grandes porcentajes del total anual pueden ocurrir en pocos días. Esta alta concentración de lluvia diaria puede causar erosión de suelos, deslizamientos o inundaciones. La concentración de lluvia diaria para toda la cuenca amazónica (CA) es caracterizada empleando un “Índice de Concentración”, el cual es estimado a partir de un producto grillado de precipitación observada para el periodo 1980-2009. Nuestros hallazgos proveen nueva información acerca de la distribución espacial de la lluvia diaria sobre la CA. Los resultados indican que la concentración de lluvia diaria es relativamente baja en Colombia, Ecuador, norte de Perú y los Andes sobre los 1500 m s. n. m., no obstante, es m...

Este trabajo ofrece un panorama inicial de las características climáticas y los impactos hidrológicos afines durante las recientes sequías extremas (1995, 1998, 2005 y 2010) en el río Amazonas peruano. Para ello se empleó una base de datos in situ de caudales y precipitaciones. Las sequías generalmente se asocian a anomalías positivas de temperatura superficial del mar (TSM) en el Atlántico tropical norte, vientos alisios y transporte de vapor de agua débiles hacia el oeste de la cuenca amazónica, que acompañados de un aumento en la subsidencia sobre la parte central y sur de la cuenca, explican la falta de lluvias y los muy bajos valores de caudales. Sin embargo, en 1998 hacia el final del evento El Niño de 1997/1998 la sequía estuvo más relacionada con una divergencia anómala de vapor de agua en el oeste de la amazonia, que es característica de un evento cálido en el ...

We previously described a divergent clinical and molecular presentation of hepatocellular carcinoma (HCC) in Peru. The present study aimed to further characterize the tissue features associated with this singular nosological form of HCC in order to gain insight into the natural history of the disease. We performed an exploratory analysis of the histology of both tumor and non-tumor liver (NTL) tissues from 50 Peruvian HCC patients, and compared with that of 75 individuals with non-HCC liver tumor or benign liver lesions as a baseline for NTL features. We complemented this approach with a transcriptome analysis in a subset of NTL tissue samples and also performed an ultra-sensitive hepatitis B virus (HBV) detection in liver tissues of the patients. Overall, results highlighted the low rate of liver parenchymal alterations in a young patient cohort (median age: 40 years old), despite a str...

In this work we document and analyze the hydrological annual cycles characterized by a rapid transition between low and high flows in the Amazonas River (Peruvian Amazon) and we show how these events, which may impact vulnerable riverside residents, are related to regional climate variability. Our analysis is based on comprehensive discharge, rainfall and average suspended sediment data sets. Particular attention is paid to the 2010–11 hydrological year, when an unprecedented abrupt transition from the extreme September 2010 drought (8300 m³ s⁻¹) to one of the four highest discharges in April 2011 (49 500 m³ s⁻¹) was recorded at Tamshiyacu (Amazonas River). This unusual transition is also observed in average suspended sediments. Years with a rapid increase in discharge are characterized by negative sea surface temperature anomalies in the central equatorial Pacific during aus...

En « Amazonie des rivières », la période de basses eaux permet la mise en culture de vastes zones exondées et fertiles sur les berges des rivières et dans les plaines d'inondation. La variabilité des extrêmes hydrologiques et celle de la structure du cycle de décrue, facteurs réputés importants pour la qualité des récoltes sont explorés à la station fluviométrique de Tamshiyacu sur le fleuve Amazonas. Le riz, culture rentable dans cette région, est notre référence. Les résultats ne présentent pas les liens supposés entre résultats agricoles et durée de la saison de basses eaux ou vitesse de remontée des eaux. Néanmoins, ils montrent la baisse des étiages, l'allongement de la durée de décrue en relation avec un retard de la montée des eaux et une accélération de la remontée des faux pendant la période 1985-2015.

Ethnopharmacological relevance: In the Peruvian Amazon as in the tropical countries of South America, the use of medicinal Piper species (cordoncillos) is common practice, particularly against symptoms of infection by protozoal parasites. However, there is few documented information about the practical aspects of their use and few scientific validation. The starting point of this work was a set of interviews of people living in six rural communities from the Peruvian Amazon (Alto Amazonas Province) about their uses of plants from Piper genus: one community of Amerindian native people (Shawi community) and five communities of mestizos. Infections caused by parasitic protozoa take a huge toll on public health in the Amazonian communities, who partly fight it using traditional remedies. Validation of these traditional practices contributes to public health care efficiency and may help to id...

In this work we document and analyze the hydrological annual cycles characterized by a rapid transition between low and high flows in the Amazonas River (Peruvian Amazon) and we show how these events, which may impact vulnerable riverside residents, are related to regional climate variability. Our analysis is based on comprehensive discharge, rainfall and average suspended sediment data sets. Particular attention is paid to the 2010–11 hydrological year, when an unprecedented abrupt transition from the extreme September 2010 drought (8300 m3s−1) to one of the four highest discharges in April 2011 (49 500 m3s−1) was recorded at Tamshiyacu (Amazonas River). This unusual transition is also observed in average suspended sediments. Years with a rapid increase in discharge are characterized by negative sea surface temperature anomalies in the central equatorial Pacific during austral sum...

Background and aims: Since mid-March 2020, over 3 billion people have been confined as a result of the COVID-19 pandemic. Problematic eating behaviors are likely to be impacted by the pandemic through multiple pathways. This study examined the relationships between stress related to lockdown measures and binge eating and dietary restriction in a population of French students during the first week of confinement. Methods: A sample of undergraduate students (N = 5,738) completed an online questionnaire 7 days after lockdown measures were introduced. The survey comprised variables related to lockdown measures and the COVID-19-pandemic, mood, stress, body image, binge eating and dietary restriction during the past 7 days, as well as intent to binge eat and restrict in the following 15 days. Results: Stress related to the lockdown was associated with greater likelihood of binge eating and die...

This study evaluated factors linked with perceived stress related to the COVID-19 pandemic and lockdown and addictive behaviors prior to and during lockdown in a sample of students who indicated engaging in alcohol consumption behaviors before lockdown. Methods: Cross-sectional study. French students from four universities participated in this study, and 2,760 students reported alcohol use. During the first week of lockdown, students reported their perceived levels of stress regarding COVID-19. Substance use and addictive behaviors were reported before and during lockdown, and media exposure, demographical, living conditions, and environmental stressors were reported during lockdown. Results: Women reported greater levels of stress (95% CI: 1.18 to 1.93, p < 0.001). Highly-stressed students also report less social support (95% CI: -1.04 to -0.39, p < 0.001) and were more likely to worry ...

The aim of this study is to evaluate the ability of the ORCHIDEE land surface model to simulate streamflows over each sub-basin of the Amazon River basin. For this purpose, simulations are performed with a routing module including the influence of floodplains and swamps on river discharge and validated against on-site hydrological measurements collected within the HYBAM observatory over the 1980–2000 period. When forced by the NCC global meteorological dataset, the initial version of ORCHIDEE shows discrepancies with ORE HYBAM measurements with underestimation by 15 % of the annual mean streamflow at Obidos hydrological station. Consequently, several improvements are incrementally added to the initial simulation in order to reduce those discrepancies. First, values of NCC precipitation are substituted by ORE HYBAM daily in-situ rainfall observations from the meteorological services of ...

Plasmablastic lymphoma (PBL) is a rare and aggressive CD20‐negative lymphoma associated with poor outcomes. Multiple studies have shown median survival times of 12–18 months (Castillo et al, 2012; Schommers et al, 2013; Morscio et al, 2014). Several case reports and small case series have suggested an increased response rate in patients treated with bortezomib alone or in combination, especially the combination of bortezomib and dose‐adjusted etoposide, prednisone, vincristine, cyclophosphamide and doxorubicin (V‐EPOCH) (Castillo et al, 2015a; Fedele et al, 2016). Due to its rarity, prospective studies exclusively in PBL patients are unlikely to be performed. We evaluated the potential therapeutic value of V‐EPOCH in patients with PBL.