Toward the realization of a primary low-pressure standard using a superconducting microwave resonator

We describe a primary gas pressure standard based on the measurement of the refractive index of helium gas using a microwave resonant cavity in the range between 500 Pa and 20 kPa. To operate in this range, the sensitivity of the microwave refractive gas manometer (MRGM) to low-pressure variations is substantially enhanced by a niobium coating of the resonator surface, which becomes superconducting at temperatures below 9 K, allowing one to achieve a frequency resolution of about 0.3 Hz at 5.2 GHz, corresponding to a pressure resolution below 3 mPa at 20 Pa. The determination of helium pressure requires precise thermometry but is favored by the remarkable accuracy achieved by ab initio calculations of the thermodynamic and electromagnetic properties of the gas. The overall standard uncertainty of the MRGM is estimated to be of the order of 0.04%, corresponding to 0.2 Pa at 500 and 8.1 Pa at 20 kPa, with major contributions from thermometry and the repeatability of microwave frequency measurements. A direct comparison of the pressures realized by the MRGM with the reference provided by a traceable quartz transducer shows relative pressure differences between 0.025% at 20 kPa and -1.4% at 500 Pa. (c) 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)

Chlamydia control activities in Europe: cross-sectional survey

Background: Chlamydia is the most commonly reported bacterial sexually transmitted infection in Europe. The objective of the Screening for Chlamydia in Europe (SCREen) project was to describe current and planned chlamydia control activities in Europe. Methods: The authors sent a questionnaire asking about different aspects of chlamydia epidemiology and control to public health and clinical experts in each country in 2007. The principles of sexually transmitted infection control were used to develop a typology comprising five categories of chlamydia control activities. Each country was assigned to a category, based on responses to the questionnaire. Results: Experts in 29 of 33 (88%) invited countries responded. Thirteen of 29 countries (45%) had no current chlamydia control activities. Six countries in this group stated that there were plans to introduce chlamydia screening programmes. There were five countries (17%) with case management guidelines only. Three countries (10%) also recommended case finding amongst partners of diagnosed chlamydia cases or people with another sexually transmitted infection. Six countries (21%) further specified groups of asymptomatic people eligible for opportunistic chlamydia testing. Two countries (7%) reported a chlamydia screening programme. There was no consistent association between the per capita gross domestic product of a country and the intensity of chlamydia control activities (P = 0.816). Conclusion: A newly developed classification system allowed the breadth of ongoing national chlamydia control activities to be described and categorized. Chlamydia control strategies should ensure that clinical guidelines to optimize chlamydia diagnosis and case management have been implemented before considering the appropriateness of screening programmes

Temperature change and Baltic sprat: from observations to ecological-economic modelling

Temperature effects on Baltic sprat are many and include both direct and indirect effects. Increasing temperature is thought to increase the survival of all early life stages, resulting in increased recruitment success. We quantified the spatially resolved temperature trend for major spawning grounds and depth layers being most relevant for sprat eggs and larvae, using a three-dimensional hydrodynamic model for 1979–2005. Results confirmed an underlying positive temperature trend. Next, we tested these time-series as new explanatory variables in an existing temperature-dependent recruitment function and applied these recruitment predictions in an agestructured ecological–economic optimization model, maximizing for profit. Economic optimal solutions depended upon variability in temperature trajectories. Under climate-change scenarios, mean optimal fishing mortality and related yields and profits increased. The extent of the increase was limited by the general shape of the stock–recruitment model and the assumption of density-dependence. This highlights the need to formulate better environmentally sensitive stock recruitment models. Under the current knowledge of Baltic sprat recruitment, the tested climate-change scenarios would result in a change in management targets. However, to serve as a quantitative management advice tool, models will have to address the above-mentioned concern

Detection of Landscape patterns in airborne LIDAR data in the Nature Reserve of Castelporziano (Rome)

During the last decades the protection of nature has become a very important aspect due to the anthropogenic interference and structural alteration of the environment, especially in the peri-urban areas. Therefore, for a sustainable forest planning it is fundamental to get information about the actual state and the variation in landscape patterns concerning the forest layers. To this aim, an airborne laser scanning (LIDAR), a type of sensor which explicitly measures canopy height, was used to detect landscape patterns of broadleaf oak forest and for detecting the monumental trees in a peri-urban Natural Reserve: the Presidential Estate of Castelporziano (Rome)

High exposure to advanced glycation End-products could facilitate the occurrence of pediatric Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a major cause of upper gastrointestinal morbidity in the pediatric age. It has been hypothesized that the interaction between genetic and environmental factors (i.e., dietary habits) may induce the development of EoE. Among dietary factors, it has been postulated that advanced glycation end-products (AGEs), present at high level in ultra-processed foods (UPFs), could be involved in the pathogenesis of several inflammatory diseases, including food allergy. AGEs are ligands to the RAGE receptor and, mimicking signals provoked by tissue damage, are capable to increase tissue permeability, inflammation and Th2 response. We aimed to evaluate the potential pathogenic role elicited by AGEs in pediatric EoE

Evaluaci\uf3n de un detergente en base a benceno sulfonato de sodio para el control de la mosquita blanca Aleurothrixus floccosus (Maskell) (Hemiptera: Aleyrodidae) y de la ara\uf1ita roja Panonychus citri (McGregor) (Acarina: Tetranychidae) en naranjos y mandarinos

The woolly whitefly Aleurothrixus floccosus (Maskell), and the red citrus red mite Panonychus citri (McGregor), are considered serious citrus pests which may cause economic damage, and the use of non selective insecticides increases the problem due to the effect on the natural enemies. To evaluate the use of detergent based on sodium benzene sulfonate on the reduction of whiteflies, mites and natural enemies, experiments were performed in two citrus orchards. The first field trial was carried out on in a mandarin orchard ( Citrus reticulata Blanco) infested by the woolly whitefly at El Palqui (IV Region, Chile). The experiment consisted of the evaluation of two applications of detergent (February 10th and March 3rd, 1998), compared with an untreated control. The results showed significant differences in A. floccosus populations between sprayed and untreated trees from May to July. The mean of parasitized nymphs between March and August was 89.6% in treated trees and 57.1% in untreated trees. The proportion of fruits at harvest with sooty mould was lower on untreated trees compared with the control, 2.3% and 45.5%, respectively. The second field trial was carried out on an orange orchard trees ( Citrus sinensis (L.) Osbeck), infested by the citrus red miteat Hijuelas (V Region) and included the following applications detergent, chinometionate, mineral oil and water. Chinometionate produced an effective control of the phytophagous mites populations and an almost total elimination of natural enemies such as phytoseiids and the coccinellid Stethorus histrio Chazeau. The application of detergent and mineral oil showed less control compared to the acaricide and less impact on populations of natural enemies.La mosquita blanca Aleurothrixus floccosus (Maskell) y la ara\uf1ita roja Panonychus citri (McGregor) son consideradas plagas que causan da\uf1os econ\uf3micos a los c\uedtricos, y el uso de insecticidas no selectivos aumenta el problema por su efecto sobre los enemigos naturales. Para evaluar el uso del detergente en base a benceno sulfonato de sodio en la reducci\uf3n de mosquitas blancas, ara\uf1itas y sus enemigos naturales se desarrollaron experimentos en dos huertos de c\uedtricos. El primer ensayo fue realizado en un huerto de mandarinos ( Citrus reticulata Blanco) infestado con mosquitas blancas en El Palqui (IV Regi\uf3n). El experimento consisti\uf3 en la evaluaci\uf3n de dos aplicaciones del detergente (10 de febrero y 3 de marzo de 1998), comparado con un control sin aplicaci\uf3n. Los resultados mostraron diferencias significativas en la presencia de A. floccosus entre \ue1rboles asperjados y no asperjados, desde mayo a julio. Entremarzo y agosto de 1998 el promedio de ninfas parasitadas en los \ue1rboles tratados fue de 89,6 y de 57,1% en las plantas sin lavar. La proporci\uf3n de frutos manchados con fumagina en la cosecha fue menor en los \ue1rboles asperjados comparados con el control, 2,3 y 45,5%, respectivamente. El segundo ensayo fue realizado en un huerto de naranjos ( Citrus sinensis (L.) Osbeck) infestado con ara\uf1ita roja de los c\uedtricos en Hijuelas (V Regi\uf3n) y consider\uf3 la aplicaci\uf3n de: detergente, chinometionate, aceite mineral y agua. Chinometionate produjo un efectivo control de las ara\uf1itas fit\uf3fagas y una eliminaci\uf3n casi total de sus enemigos naturales representados por fitoseidos y el coccin\ue9lido Stethorus histrio Chazeau. La aplicaci\uf3n del detergente y el aceite mineral mostraron una actividad inferior al acaricida y un impacto menor sobre las poblaciones de enemigos naturales