On the possible use of hydraulic force to assist with building the step pyramid of saqqara.

The Step Pyramid of Djoser in Saqqara, Egypt, is considered the oldest of the seven monumental pyramids built about 4,500 years ago. From transdisciplinary analysis, it was discovered that a hydraulic lift may have been used to build the pyramid. Based on our mapping of the nearby watersheds, we show that one of the unexplained massive Saqqara structures, the Gisr el-Mudir enclosure, has the features of a check dam with the intent to trap sediment and water.

Analytical strategies for sensitive and precise determination of Sr/Sr in olive oil through ion extraction, chromatographic separation, and multicollector inductively-coupled plasma mass-spectrometry.

Several food regulatory bodies regard olive oil as highly susceptible to food fraud, largely due to its substantial economic worth. Precise analytical tools are being developed to uncover these types of fraud. This study examines an innovative approach to extract strontium (Sr) from the olive oil matrix (via EDTA complexation and ion-exchange chromatography) and to determine its isotope composition by MC-ICP-MS.

Organ-specific mercury stable isotopes, speciation and particle measurements reveal methylmercury detoxification processes in Atlantic Bluefin Tuna.

Identifying metabolism and detoxification mechanisms of Hg in biota has important implications for biomonitoring, ecotoxicology, and food safety. Compared to marine mammals and waterbirds, detoxification of MeHg in fish is understudied. Here, we investigated Hg detoxification in Atlantic bluefin tuna Thunnus thynnus using organ-specific Hg and Se speciation data, stable Hg isotope signatures, and Hg and Se particle measurements in multiple tissues.

Discontinuous codimension-two bifurcation in a Vlasov equation.

In a Vlasov equation, the destabilization of a homogeneous stationary state is typically described by a continuous bifurcation characterized by strong resonances between the unstable mode and the continuous spectrum. However, when the reference stationary state has a flat top, it is known that resonances drastically weaken and the bifurcation becomes discontinuous. In this article we analyze one-dimensional spatially periodic Vlasov systems, using a combination of analytical tools and precise numerical simulations to demonstrate that this behavior is related to a codimension-two bifurcation, which we study in detail.

Combined use of Sr/Sr and carbon isotopes with multielemental analysis for the geographical authentication of Tunisian and European olive oils.

The geographical authentication in the agrifood industry has become a major issue to guarantee the quality of food products. Olive oil (OO) is particularly a complex matrix and establishing a reliable approach for linking OO samples to their origin is an analytical challenge. In this study, the isotopic composition of carbon, strontium and the concentrations of seventeen elements were determined in OOs from Tunisia, Southern France and the South Basque country.

Authenticating teas using multielement signatures, strontium isotope ratios, and volatile compound profiling.

High value food products are subject to adulterations and frauds. This study aimed to combine, in our knowledge for the first time, inorganic chemical tracers (multi-elements and Sr isotopy) with volatile organic compound (VOCs) to discriminate the geographic origin, the varieties and transformation processes to authenticate 26 tea samples. By measuring Sr isotope ratio using the multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), 6 out of 11 regions were successfully discriminated.

Widespread Frequent Methane Emissions From the Oil and Gas Industry in the Permian Basin.

Emissions of methane (CH) in the Permian basin (USA) have been derived for 2019 and 2020 from satellite observations of the Tropospheric Monitoring Instrument (TROPOMI) using the divergence method, in combination with a data driven method to estimate the background column densities. The resulting CH emission data, which have been verified using model data with known emissions, have a spatial resolution of approximately 10 km. The CH emissions show moderate spatial correlation with the locations of oil and gas production and drilling activities in the Permian basin, as well as with emissions of nitrogen oxides (NO).

Evaluation of selected botanicals for the management of maize weevil () on maize ( L.) grain under laboratory condition in Gabilay District, Somaliland.

One of the most reliable crops in the research region is maize. However, a variety of post-harvest insect pests like Sitophilus zeamais and Angoumois grain moths pose a hazard to the cultivation and storage of maize. Hence, a laboratory experiment was conducted in Gabilay District Somaliland in 2021 to assess selected botanicals effectiveness against maize weevil.

An Integrative Review of Measures of Secondary Traumatic Stress.

Secondary traumatic stress (STS) results in detrimental effects in healthcare professionals, impacting the safety of patients and their care. There are multiple instruments being used to measure STS, reflecting the uncertainty on how to best measure STS. The purpose of this review is to present an overview of the state of measurement of STS.

Differential impact of government lockdown policies on reducing air pollution levels and related mortality in Europe.

Previous studies have reported a decrease in air pollution levels following the enforcement of lockdown measures during the first wave of the COVID-19 pandemic. However, these investigations were mostly based on simple pre-post comparisons using past years as a reference and did not assess the role of different policy interventions. This study contributes to knowledge by quantifying the association between specific lockdown measures and the decrease in NO, O, PM, and PM levels across 47 European cities.

Specificity and Origin of the Stability of the Sr Isotopic Ratio in Champagne Wines.

The Sr/Sr ratio of 39 Champagnes from six different brands, originating from the whole "Appellation d'Origine Contrôlée" (AOC) Champagne was analyzed to establish a possible relation with the geographical origin. Musts (i.e.

Analytical strategies for Sr and Pb isotopic signatures by MC-ICP-MS applied to the authentication of Champagne and other sparkling wines.

Wine is one of the most counterfeit product and therefore, requires certifying of its origin and provenance. For authentication purposes, analytical strategies for the determination of Sr and Pb isotopic ratios were adapted for Champagne and sparkling wines. All analytical steps have been carefully adapted and optimized regarding sample preparation, mineralization, and purification by resins as well as isotopic composition measurements on 3 different MC ICP-MS instruments.

Investigating unmet need for healthcare using the European Health Interview Survey: a cross-sectional survey study of Luxembourg.

Objectives: We investigate the prevalence of unmet need arising from wait times, distance/transportation and financial affordability using the European Health Interview Survey. We explore associations between individual characteristics and the probability of reporting unmet need.

Design: Cross-sectional survey conducted between February and December 2014.

Hg isotopic composition of one-year-old spruce shoots: Application to long-term Hg atmospheric monitoring in Germany.

The Hg isotopic composition of 1-year-old Norway spruce (Picea abies) shoots collected from Saarland cornurbation Warndt, Germany, since 1985 by the German Environmental Specimen Bank, were measured for a better understanding of the temporal trends of Hg sources. The isotopic data showed that Hg was mainly taken up as gaseous element mercury (GEM) and underwent oxidation in the spruce needles; this led to a significant decrease in the δHg compared with the atmospheric Hg isotopic composition observed for deciduous leaves and epiphytic lichens. Observation of the odd mass-independent isotopic fractionation (MIF) indicated that ΔHg and ΔHg were close to but slightly lower than the actual values recorded from the atmospheric measurement of the GEM isotopic composition in non-contaminated sites in U.

Towards a classification of bifurcations in Vlasov equations.

We propose a classification of bifurcations of Vlasov equations, based on the strength of the resonance between the unstable mode and the continuous spectrum on the imaginary axis. We then identify and characterize a new type of generic bifurcation where this resonance is weak, but the unstable mode couples with a stable mode and a Casimir invariant of the system to form a size-3 Jordan block. We derive a three-dimensional reduced noncanonical Hamiltonian system describing this bifurcation.

Montelukast Drug May Improve COVID-19 Prognosis: A Review of Evidence.

With the lack of effective therapy, chemoprevention and vaccination, focusing on the immediate repurposing of existing drugs gives hope of curbing the pandemic. Interestingly, montelukast, a drug usually used in asthma, may be proposed as a potential adjuvant therapy in COVID-19. The aim of the present article was to review the properties of montelukast that could be beneficial in COVID-19.

Effect of Computer Debriefing on Acquisition and Retention of Learning After Screen-Based Simulation of Neonatal Resuscitation: Randomized Controlled Trial.

Background: Debriefing is key in a simulation learning process.

Objective: This study focuses on the impact of computer debriefing on learning acquisition and retention after a screen-based simulation training on neonatal resuscitation designed for midwifery students.

Methods: Midwifery students participated in 2 screen-based simulation sessions, separated by 2 months, session 1 and session 2.

Hg isotopic composition and total Hg mass fraction in NIES Certified Reference Material No. 28 Urban Aerosols.

An interlaboratory study on the National Institute for Environmental Studies (NIES) certified reference material (CRM) No. 28 Urban Aerosols, collected on the filters of a central ventilating system in a building in Beijing city center, was performed to obtain informative values of Hg isotopic composition and total Hg (THg) mass fraction. The THg mass fraction was determined by four organizations using atomic absorption spectrometry; it resulted in the mean value of 1.

Midwifery students' retention of learning after screen-based simulation training on neonatal resuscitation: a pilot study.

Simulation in medical education is widely used to teach both technical and non-technical skills. The use of tools such as screen-based simulation raises the question of their efficiency and the retention rate for knowledge and skills. In this study, we measured midwives' retention of learning after screen-based simulation training on neonatal resuscitation.

Benefits of Screen-Based Postpartum Hemorrhage Simulation on Nontechnical Skills Training: A Randomized Simulation Study.

Background: Postpartum hemorrhage (PPH) is the leading cause of maternal death in the world. Nontechnical skills (NTS), such as communication and teamwork, are critical for efficient management of this obstetric emergency. Specific scenarios were designed on a screen-based simulator to train NTS.

Potential of lead elemental and isotopic signatures for authenticity and geographical origin of Bordeaux wines.

Lead concentrations and lead isotope ratios of 43 authentic Bordeaux wines from prestigious châteaux and 14 suspicious Bordeaux origin were determined to evaluate their potential for authenticity and geographical origin assessment. Results have shown that the total Pb concentrations in Bordeaux wines drastically decreased over the previous 50 years with a clear shift of isotopic signatures towards geogenic values corresponding to an overall trend of European environmental lead monitoring. The Pb isotopic ratios determined in both series of samples clearly demonstrated that suspicious Bordeaux wines displayed Pb isotopic signatures statistically distinctive from those obtained for authentic wines.