bluuebunny/crossref_metadata_2025 huggingface dataset:
Clostridium difficile Infection Epidemiology over a Period of 8 Years—A Single Centre Study
Authors: Negrut Nicoleta , Nistor-Cseppento Delia Carmen , Khan Shamim Ahmad , Pantis Carmen , Maghiar Teodor Andrei , Maghiar Octavian , Aleya Selim , Rus Marius , Tit Delia Mirela , Aleya Lotfi , Rahdar Abbas , Bungau Simona
Published: June 2020

Clostridium difficile infection (CDI) is the most common infectious disease related to antibiotic-associated diarrhoea and is a current leading cause of morbidity/mortality, with substantial consequences for healthcare services and overall public health. Thus, we performed a retrospective epidemiological study of CDI for a long period (8 years), in an infectious hospital located in north-western Romania, which serves an entire county of the country (617,827 inhabitants). From 2011 to 2018, 877 patients were diagnosed with CDI; the mean incidence of this disease was 2.76 cases/10,000 patient-days, with an increasing trend in the annual incidence until 2016, at which point there was a decrease. The most commonly afflicted were patients in the 75–84 age group, observed in winter and spring. The results show that the antibiotics were administered in 679 (77.42%) subjects, within the last 3 months before CDI, statistically significant more than proton-pump inhibitors (PPIs)—128 (14.60%) and antidepressant medications—60 (6.84%), which were administered during the same period (p < 0.001). No medication was reported in 10 (6.84%) cases of CDI, in the last 3 months of the study. The fatality rate attained 4.1%, tripling in 2018 vs. 2011. CDI became a significant public health conundrum that can, nevertheless, be combatted through a judicious use of antibiotics.
Quantifying the Spatial Association between Land Use Change and Ecosystem Services Value: A Case Study in Xi’an, China
Authors: Shao Yajing , Yuan Xuefeng , Ma Chaoqun , Ma Ruifang , Ren Zhaoxia
Published: June 2020

The impact of land use and land cover (LULC) change on ecosystem services value (ESV) varies in different spatial locations. Although many studies have focused on quantifying the effect of LULC change on ESV, few have considered the spatial heterogeneity of the relationship between LULC change and ESV. Therefore, this study examines the relationship between ESV and LULC change from a spatial perspective in Xi’an City. We divide the study area into 10,522 grid cells, based on land cover data from 2000 to 2018, and we identify the spatial-temporal dynamics of LULC change. Next, we employ the Benefits Transfer Method (BTM) to evaluate the ESV, and the ESV is corrected by the normalized difference vegetation index (NDVI). A geographically weighted regression (GWR) model and ordinary least squares (OLS) regression model are used to assess the spatial association of LULC change and ESV. The results show that the total ESV loss is 6.57 billion yuan (Chinese yuan), and the loss rate is 12.18%. The distribution of ESV shows an obvious spatial heterogeneity, and the low-value area of ESV expands eastward from the main urban area. More than 50% of total ESV is provided by woodland. From 2000 to 2018, the land use pattern in Xi’an underwent a significant change with the developed land increasing by 64.09%, whereas farmland decreased by 12.49%. Based on the GWR model, the relationship between LULC change and ESV in Xi’an showed a significant negative association and spatial heterogeneity. Our study results provide a new way to effectively identify the relationship between LULC change and ESV, and in turn, to fully understand the ecological trends at the regional scale, laying a foundation for regional sustainable development.
Waste Management through Composting: Challenges and Potentials
Authors: Ayilara Modupe , Olanrewaju Oluwaseyi , Babalola Olubukola , Odeyemi Olu
Published: June 2020

Composting is the controlled conversion of degradable organic products and wastes into stable products with the aid of microorganisms. Composting is a long-used technology, though it has some shortcomings that have reduced its extensive usage and efficiency. The shortcomings include pathogen detection, low nutrient status, long duration of composting, long mineralization duration, and odor production. These challenges have publicized the use of chemical fertilizers produced through the Haber–Bosch process as an alternative to compost over time. Chemical fertilizers make nutrients readily available to plants, but their disadvantages outweigh their advantages. For example, chemical fertilizers contribute to greenhouse effects, environmental pollution, death of soil organisms and marine inhabitants, ozone layer depletion, and human diseases. These have resulted in farmers reverting to the application of composts as a means of restoring soil fertility. Composting is a fundamental process in agriculture and helps in the recycling of farm wastes. The long duration of composting is a challenge; this is due to the presence of materials that take a longer time to compost, especially during co-composting. This review discusses the proper management of wastes through composting, different composting methods, the factors affecting composting, long-duration composting, the mechanism behind it, the present trends in composting and prospects. The extraction of mono-fertilizers from compost, development of strips to test for the availability of heavy metals and pathogens as well as an odor-trapping technique can go a long way in enhancing composting techniques. The addition of activators to raw materials can help to improve the nutritional quality of compost. This review further recommends that degradable organic material in which composts slowly should be assessed for their ability to mineralize slowly, which could make them advantageous to perennial or biennial crops. Viricides, fungicides, anti-nematodes, and anti-bacterial of plant or organic sources could as well be added to improve compost quality. The enhancement of composting duration will also be useful.
SDG-Based Sustainability Assessment Methodology for Innovations in the Field of Urban Surfaces
Authors: Henzler Kristina , Maier Stephanie D. , Jäger Michael , Horn Rafael
Published: June 2020

The sustainability of urban surfaces can be enhanced by introducing innovations. An ex-ante assessment of the potential sustainability impacts of innovations in urban areas can provide decision-makers with valuable recommendations for their selection before implementation. This knowledge helps to make the innovation more future-proof. Although a first methodological approach for such an assessment is available, there is no readily applicable set of indicators. Hence, this article proposes a holistic sustainability impact assessment method tailored to the management of urban surfaces and their innovations. For the development of the method, a Sustainable Development Goal (SDG)-based, top-down approach is adopted. The proposed assessment method makes it possible to identify an innovation’s potential contribution to the achievement of the SDGs before its introduction. In this article, the assessment method is tested by evaluating the sustainability impacts of weed-suppressing joint filling sand on a walkway in a municipal cemetery in Southern Germany. The case study shows that a mixed impact of the innovation in the three dimensions of sustainability could be expected within the system boundary. It highlights the need for innovation optimization, mainly in the economic dimension. As a result, the introduced method can support the innovation process of urban surfaces for sustainable municipal development.
Indicators to Measure Efficiency in Circular Economies
Authors: Sánchez-Ortiz Jaime , Rodríguez-Cornejo Vanesa , Del Río-Sánchez Rosario , García-Valderrama Teresa
Published: June 2020

In this paper, a number of indicators are shown to measure economic efficiency in terms of circular economy (CE). The European Union affirms the need for a comprehensive model of indicators relating to CE in order to meet the needs of all participants (individual companies and industry, society, and the nation), to be based on three perspectives: environmental impact, economic benefit, and resource scarcity. Therefore, the objective of this work is to define these indicators and establish models for measuring the efficiency of processes and products of CE (through Data Envelopment Analysis, (DEA)) in its different manifestations. The models will be useful for both organizations and external users in relation to CE in order to facilitate the search for indicators for all users. Following the bibliographic review of official reports and different high impact works, our results demonstrate the ability to obtain information concerning the main indicators of CE and how the efficiency of CE models has been measured through the most frequently used inputs and outputs.
A Case Study on Environmental Sustainability Assessment of Spatial Entities with Anthropogenic Activities: The National Park of Eastern Macedonia and Thrace, Greece
Authors: Aktsoglou Despoina , Gaidajis Georgios
Published: June 2020

The current paper presents a methodological framework that is able to evaluate the carrying capacity of protected areas where various human activities, apart from recreation and tourism, take place. The proposed framework converts the energy and product consumption into land required to satisfy those needs (Ecological Footprint) and compares them with the current land uses and available land (Biocapacity), in order to calculate carrying capacity. To facilitate the evaluation, an algorithm that calculates the Ecological Footprint, the Biocapacity, and the Carrying Capacity of the protected area under study by introducing 48 inputs was developed. The inputs were related to the evaluation of individual indicators assessing energy and product consumption of human activities such as households, tertiary sector, municipal buildings, public lighting, private and public transportation, and tourism. A new unit is introduced, the “equivalent person,” since the anthropogenic activities within the boundaries of the protected area contribute in a dissimilar way to the total land requirements. The framework is applied, as case study, in the National Park of Eastern Macedonia and Thrace (NPEMT), Greece, with a view to validate and improve its applicability. Within the NPEMT, habitats of significant biodiversity and ecological value are in coexistence with extensive human activities (urban, rural, tourist, light industrial). The study area covers up to approximately 73,000 ha and its population is estimated at about 29,000 people. The Carrying Capacity of the NPEMT according to the current consumption patterns was estimated at 39,193 equivalent residents, which was higher than the current equivalent residents (36,960), indicating a potential for tourism development at the NPEMT. The Ecological Footprint of the NPEMT was estimated at 181,324 Gha or 4.9 Gha/perseq, slightly higher than the European mean (4.69 Gha/perseq). Among activities, households and private transportation (with approximately 79% and 10%, respectively), among land use, agriculture, livestock, and CO2 emissions (with approximately 36%, 30%, and 30%, respectively), and among products, beef, fruits/vegetables, and beverages (with approximately 22%, 15%, and 14%, respectively) were the main contributors of the total Ecological Footprint of the NPEMT. The area of the NPEMT is able to meet the needs of its population provided that the consumption patterns will be stable. The results encourage the expansion of tourism development, as the tourism activity within the NPEMT is limited compared to other adjacent domestic destinations.
Detecting and Analyzing Land Use and Land Cover Changes in the Region of Al-Jabal Al-Akhdar, Libya Using Time-Series Landsat Data from 1985 to 2017
Authors: Alawamy Jamal Suliman , Balasundram Siva K. , Mohd. Hanif Ahmad Husni , Boon Sung Christopher Teh
Published: June 2020

The region of Al-Jabal Al-Akhdar in northeastern Libya has undergone rapid, wide-ranging changes in the land use and land cover (LULC) intensified by the conversion of natural resources for food purpose, urbanization, and other socioeconomic benefits. This study examined the use of geographic information system (GIS) and remote sensing techniques to gain a quantitative understanding of the spatiotemporal dynamics of LULC. In addition, the major factors behind LULC changes and decline of natural vegetation in the region were analyzed. A post-classification comparison approach was used to detect LULC changes in the study area between 1985 and 2017 using four Landsat images from 1985, 2000, 2010, and 2017. The observed changes were indicative of a decrease in the expanse of the natural Mediterranean forest which lost 9018 ha over 32 years, 39% of its total area, with the highest deforestation rate registered between 2010 and 2017 estimated at 513 ha. year−1. Orchards and rain-fed agriculture lands gained 4095 ha, which matches 55% of initial area, whereas the land under irrigated crops increased by 2266 ha, about 85% of the original area. The area of urban and built-up land in 2017 was more than double in 1985 and achieved the highest urbanization rate between 2010 and 2017 at 203 ha.year−1. Results indicate an unstable trend of bare and low vegetation lands which generally increased by about 50%. From the outcomes of this research, it is strongly recommended that urgent measures be taken to conserve the natural forest and to achieve a rational use of agricultural land in the region of Al-Jabal Al-Akhdar.
Case Study Analysis of Sustainability Reporting of an Agri-Food Giant
Authors: Jindřichovská Irena , Kubíčková Dana , Mocanu Mihaela
Published: June 2020

The purpose of this study was to contribute to the discussion of how large companies in the agri-food sector cope with the growing pressure to perform sustainably and how they disclose sustainability-related information to their stakeholders. To achieve this goal, we used the case study method. We analyzed Cargill’s specific approach to sustainability reporting, who is a company with a 150-year history and worldwide activities. We used reports from the year 2014 and 2018. The core of our analysis lies in the content analysis of the text using 39 corporate social responsibility (CSR) keywords (Cohen, 2010). The frequency of keywords related to the three aspects of CSR was measured to reveal the areas that the company considers most important and those upon which it draws the attention of users. To complement this analysis, we then investigated the linguistic features of Cargill’s sustainability reports, which employed the LIWC2015 program (LIWC–Linguistic Inquiry and Word Count) and focused on four features of disclosure (analytical thinking, clout, authenticity, and emotional tone). The findings of our research confirmed that the dominant companies in the agri-food business have reacted to challenges of their social environment and changed their attitude to keep up with the current stage of social development. Sustainability reporting is elaborated and covers all aspects of the company’s activity in sufficient detail. This attitude developed continuously despite it not always being appreciated by Cargill’s stakeholders. The main limitation of our study lies in the method which did not allow even with the greatest effort to eliminate subjectivity. The other limitation relates to the specific features of the company and its position within the world economy and also to its long history, which determined the form and extent of reporting. However, our findings are indicative and inspiring for future research. Our results contribute to the debate concerning the form, content, and evolution of sustainability reporting. Moreover, our results can be used in practice by corporate management, when designing their marketing strategy, plans, and programs. We claim that the biggest challenge for big multinationals like Cargill in these days is to effectively protect the nature and respect the law in jurisdictions where there is traditionally low incentive to obey the rules because of poor regulations and many opportunities to misuse their dominant position.
The Impact of Green Credit Policy on Technological Innovation of Firms in Pollution-Intensive Industries: Evidence from China
Authors: Ling Shixian , Han Guosheng , An Dong , Hunter William Cannon , Li Hui
Published: June 2020

How to promote technological innovation with green finance policy has been a focal topic in the global green finance field in recent years. Using the difference-in-difference approach model, this paper investigated the impact of the Green Credit Guidance (GCG) policy implemented by the Chinese government in 2012 on the technological innovation of firms in pollution-intensive industries. The empirical results indicated that GCG had a negative impact, not only on research and development (R&D) input, but also on innovation output, and the impacts on firms with different property rights and different scales were consistent. Further research showed that GCG reduced the long-term debt of firms in pollution-intensive industries, and then significantly decreased the R&D input and innovation output; that is, long-term debt is a mediator in GCG and technology innovation. The results revealed that GCG fails to promote the technological innovation of firms in pollution-intensive industries. This paper suggests that China’s green credit policy should pay more attention to the technological innovation, transformation, and upgrading of firms in pollution-intensive industries.
Application of a Gray-Based Decision Support Framework for Location Selection of a Temporary Hospital during COVID-19 Pandemic
Authors: Hashemkhani Zolfani Sarfaraz , Yazdani Morteza , Ebadi Torkayesh Ali , Derakhti Arman
Published: June 2020

The hospital location selection problem is one of the most important decisions in the healthcare sector in big cities due to population growth and the possibility of a high number of daily referred patients. A poor location selection process can lead to many issues for the health workforce and patients, and it can result in many unnecessary costs for the healthcare systems. The COVID-19 outbreak had a noticeable effect on people’s lives and the service quality of hospitals during recent months. The hospital location selection problem for infected patients with COVID-19 turned out to be one of the most significant and complicated decisions with many uncertain involved parameters for healthcare sectors in countries with high cases. In this study, a gray-based decision support framework using criteria importance through inter-criteria correlation (CRITIC) and combined compromise solution (CoCoSo) methods is proposed for location selection of a temporary hospital for COVID-19 patients. A case study is performed for Istanbul using the proposed decision-making framework.
A Novel Retrovirus (Gunnison’s Prairie Dog Retrovirus) Associated With Thymic Lymphoma in Gunnison’s Prairie Dogs in Colorado, USA
Authors: Butler Molly D. , Griffin Karen , Brewster Connie D. , Kapuscinski Marylee L. , Stenglein Mark D. , Tripp Daniel W. , Quackenbush Sandra L. , Fox Karen A.
Published: June 2020

As part of research and wildlife disease surveillance efforts, we performed necropsy examinations of 125 free-ranging (n = 114) and captive (n = 11) prairie dogs in Colorado from 2009 to 2017. From these cases, we identified three cases of thymic lymphoma in free-ranging Gunnison’s prairie dogs (Cynomys gunnisoni), and we identified a novel retroviral sequence associated with these tumors. The viral sequence is 7700 nucleotides in length and exhibits a genetic organization that is consistent with the characteristics of a type D betaretrovirus. The proposed name of this virus is Gunnison’s prairie dog retrovirus (GPDRV). We screened all 125 prairie dogs for the presence of GPDRV using PCR with envelope-specific primers and DNA extracted from spleen samples. Samples were from Gunnison’s prairie dogs (n = 59), black-tailed prairie dogs (Cynomys ludovicianus) (n = 40), and white-tailed prairie dogs (Cynomys leucurus) (n = 26). We identified GPDRV in a total of 7/125 (5.6%) samples including all three of the prairie dogs with thymic lymphoma, as well as spleen from an additional four Gunnison’s prairie dogs with no tumors recognized at necropsy. None of the GPDRV-negative Gunnison’s prairie dogs had thymic lymphomas. We also identified a related, apparently endogenous retroviral sequence in all prairie dog samples. These results suggest that GPDRV infection may lead to development of thymic lymphoma in Gunnison’s prairie dogs.
Evaluation of Symmetric Dimethylarginine (SDMA) in Dogs with Acute Pancreatitis
Authors: Gori Eleonora , Pierini Alessio , Lippi Ilaria , Meucci Valentina , Perondi Francesca , Marchetti Veronica
Published: June 2020

Symmetric dimethylarginine (SDMA) is considered an important biomarker of kidney dysfunction. The aims of the study were to evaluate SDMA in dogs with acute pancreatitis (AP) and its relationship with the presence of kidney injury and mortality. A cohort study including fifty-four dogs with AP diagnosed using compatible clinical and laboratory parameters, abnormal SNAP cPL and compatible abdominal ultrasound within 48 h from admission, was conducted. Dogs with history of renal and/or urinary diseases were excluded, along with dogs exposed to nephrotoxic drugs. Serum urea and creatinine and urinary output (UO) were recorded. Acute kidney injury (AKI) was diagnosed and graded using International Renal Interest Society (IRIS) guidelines. SDMA was measured using high performance liquid chromatography. Fifty-four dogs were included and divided in non-AKI (n = 37) and AKI dogs (n = 17). Twenty-three dogs (14 non-AKI) had SDMA > 15 μg/dL. Median SDMA was higher in AKI dogs than non-AKI dogs (25.7 vs. 13.93 μg/dL; p = 0.03). Dogs with normal creatinine (AP and AKI 1 dogs) had SDMA above reference range in 38% and 33% of cases, respectively. In AKI dogs, SDMA and creatinine were positively correlated (p = 0.006 r = 0.7). SDMA was not significantly different between survivors and non-survivors. Although further studies are warranted, SDMA may be a useful tool in canine AP, as a high SDMA may be related to subclinical kidney impairment.
Accuracy of blood-pressure monitors owned by patients with hypertension (ACCU-RATE study): a cross-sectional, observational study in central England
Authors: Hodgkinson James A , Lee Mei-Man , Milner Siobhan , Bradburn Peter , Stevens Richard , Hobbs FD Richard , Koshiaris Constantinos , Grant Sabrina , Mant Jonathan , McManus Richard J
Published: June 2020

Background

Home blood-pressure (BP) monitoring is recommended in guidelines and is increasingly popular with patients and health professionals, but the accuracy of patients’ own monitors in real-world use is not known.

Aim

To assess the accuracy of home BP monitors used by people with hypertension, and to investigate factors affecting accuracy.

Design and setting

Cross-sectional, observational study in urban and suburban settings in central England.

Method

Patients (n = 6891) on the hypertension register at seven practices in the West Midlands, England, were surveyed to ascertain whether they owned a BP monitor and wanted it tested. Monitor accuracy was compared with a calibrated reference device at 50 mmHg intervals between 0–280/300 mmHg (static pressure test); a difference from the reference monitor of +/−3 mmHg at any interval was considered a failure. Cuff performance was also assessed. Results were analysed by frequency of use, length of time in service, make and model, monitor validation status, purchase price, and any previous testing.

Results

In total, 251 (76%, 95% confidence interval [95% CI] = 71 to 80%) of 331 tested devices passed all tests (monitors and cuffs), and 86% (CI] = 82 to 90%) passed the static pressure test; deficiencies were, primarily, because of monitors overestimating BP. A total of 40% of testable monitors were not validated. The pass rate on the static pressure test was greater in validated monitors (96%, 95% CI = 94 to 98%) versus unvalidated monitors (64%, 95% CI = 58 to 69%), those retailing for >£10 (90%, 95% CI = 86 to 94%), those retailing for ≤£10 (66%, 95% CI = 51 to 80%), those in use for ≤4 years (95%, 95% CI = 91 to 98%), and those in use for >4 years (74%, 95% CI = 67 to 82%). All in all, 12% of cuffs failed.

Conclusion

Patients’ own BP monitor failure rate was similar to that demonstrated in studies performed in professional settings, although cuff failure was more frequent. Clinicians can be confident of the accuracy of patients’ own BP monitors if the devices are validated and ≤4 years old.
ARCHITECTURE PLANNING AND DESIGN CONCEPTS OF PRIMARY HEALTH CARE INSTITUTIONS IN YEMEN
Authors: Kolesnikova T. , Hasan Al'-Nahari Mohammed
Published: June 2020

This article discusses the main aspects of the location of primary health care facilities in Yemen. We studied the requirements directly for the site of such medical care institutions. It is also revealed how to determine the correct orientation of the building center. In addition, the functional components and construction sites of primary care facilities are described. The components of a medical center include: the first floor – a medical center, the second floor - a doctor's apartment, a security room, an electric generator, an incinerator for medical waste, and a fence for a medical center. The article defines the architectural principles and elements of the project of medical centers. These elements of the project of primary health care institutions include: the main entrance, administrative department, medical services section, examination rooms, rest rooms, radiology room, surgical ward, pharmacy, mechanics section. The general design assumptions for the building of primary health care are discussed. Design standards for these institutions are identified.
Sur l'évolution d'un gaz de Lorentz faiblement couplé
Authors: Mazo Robert M. , Résibois Pierre M. V.
Published: June 2020

We consider the evolution of the velocity distribution function for a light particle, weakly coupled to a medium of heavy particles. To second order in the mass ratio, it is shown that the problem is characterized by two time scales : the shorter corresponds to a sphericalization of the velocity distribution ; the longer describes the approach of this spherical distribution to a Maxwellian. We prove that the spectrum of eigenvalues describing this latter thermalization process is continuous, implying a non exponential approach to equilibrium. This feature is also illustrated by an approximate solution of the kinetic equation of the problem.
On linearized hydrodynamical modes in statistical physics. II : The sound absorption coefficient
Authors: Résibois Pierre M. V.
Published: June 2020

Dans un travail récent, nous avons obtenu des expressions microscopiques pour les coefficients de transport linéaires en formulant le problème des modes hydrodynamiques linéarisés à partir de l'équation de Boltzmann généralisée. Nous montrons ici que l'expression microscopique que nous avons déduite pour le coefficient d'absorption du son est en accord complet avec celle qu'on peut obtenir à partir des formules d'autocorrélation.
Étude par spectrométrie de masse de l'apparition des ions négatifs par attachement électronique dissociatif dans des molécules polyatomiques
Authors: Locht R.
Published: June 2020

The appearance of negative ions by dissociative electron attachment has been studied by electron impact on CH4, C2H2, C2H4 and C2H3X (X = F, CI) using a sectorfield mass spectrometer. An interpretation has been attempted for the measured appearance potentials. The electroaffinity of C2 and C2H radicals is found to be (3,3 ± 0,3) eV and (2,3 ± 0,2) eV respectively. Some evidence is brought for the existence of excited electronic states in polyatomic negative ions.
Spectre micro-onde de deux états vibrationnels excités de l'acide formique. Effet d'une résonance de Coriolis forte
Authors: Samson C. , Steenbeckeliers Guy , Willemot Edmond , Bellet Jean
Published: June 2020

Les spectres micro-ondes des états vibrationnels excités ν7 et ν9 de l'acide formique ont été identifiés et mesurés. Ces états vibrationnels sont en résonance de type Coriolis forte. Un modèle théorique simplifié a été utilisé ; il permet de proposer des constantes de rotation et d'interaction.
Action of Electromagnetic Radiations on Proteins. II. Irradiation of Bovine Serum Albumin by Ultraviolet Rays
Authors: Colson C.
Published: June 2020

Summary. — Bovine serum albumin solutions (l g/dl, pH 7) have been treated by ultraviolet radiations in air and in nitrogen.
Excitation de l'atome d'Hélium par un proton rapide
Authors: Baye D.
Published: June 2020

L'excitation de l'hélium par un proton d'énergie supérieure à 25 keV est étudiée par la méthode de diagonalisation. Les fonctions d'onde choisies comportent au moins 15 paramètres en variables r1, θ1, φ1, r2, θ2, φ2 et forment un ensemble orthonormé jusqu'à n = 5. Les peuplements des états n1 S sont en désaccord avec l'expérience en dessous de 400 keV. Les peuplements des états n1 P sont en accord avec l'expérience au-dessus de 100 keV. Jusqu'à plusieurs MeV, les peuplements des états n1 D et 41 F sont nettement supérieurs à ceux donnés par l'approximation de Born et aux valeurs expérimentales. Les polarisations calculées pour les raies 1 D-1P sont en excellent accord avec les résultats expérimentaux.
Relation entre les genres arithmétiques de deux surfaces en correspondance rationnelle
Authors: Godeaux Lucien
Published: June 2020

Méthode pour déterminer la relation existant entre le genre arithmétique d'une surface et celui de la surface image d'une involution cyclique d'ordre premier n'ayant qu'un nombre fini de points unis, appartenant à la première surface.
Définition d'un principe de limitation de modules dans la détermination et le calcul des intégrales des équations différentielles ordinaires par des itérations intégrales convergentes. Application à des systèmes du premier ordre
Authors: Lahaye Edmond
Published: June 2020

En introduisant un principe de limitation du module de certaines expressions dans le calcul, par la méthode des approximations successives, des intégrales de systèmes d'équations différentielles ordinaires, nous démontrons que la convergence uniforme est réalisée en tout point d'une courbe du domaine complexe de longueur arbitrairement grande, ne contenant aucune singularité. Dans ces conditions, les relations qui interviennent dans la méthode des approximations successives sont définies comme étant des itérations intégrales convergentes.

Dans cette Note, la méthode est appliquée à des systèmes d'équations différentielles du premier ordre.
Recherche numérique d'oscillations composées du type additif dans un système oscillant non-linéaire amorti à deux degrés de liberté
Authors: Van Dooren René
Published: June 2020

The combination tones of summed type are studied in a non-linear damped vibratory system of two degrees of freedom with spring characteristics of second and third order and excited by two external harmonic forces of different frequencies. A modified Galerkin method is presented, based on the replacement of some integrals by their Simpson approximations instead of using the formulae given by M. Urabe. For some systems this modified method has the advantage to ameliorate the precision of the Galerkin approximations and to diminish considerably the error of these approximations. The existence and stability of an exact periodic solution is discussed and the error bound of the Galerkin approxi¬ mations is given. The modified Galerkin method is compared to other approximation methods for two numerical examples.
Quelques propriétés des ensembles convexes linéairement bornés et des ensembles insérables (première note)
Authors: Coquet Gérard , Dupin Jean-Claude
Published: June 2020

Dans cette note, nous mettons en évidence, dans un espace vectoriel topologique de dimension infinie et non muni de la topologie grossière, une infinité d'ensembles convexes qui sont symétriques, absorbants, linéairement bornés et non bornés. Nous donnons des conditions suffisantes permettant d'affirmer que l'enveloppe convexe de la réunion d'ensembles linéairement bornés est aussi linéairement bornée.
Essais de chloration dirigée. XXI. Étude de la photochloration de bromoalcanes
Authors: Gouverneur P. , Bruylants Albert
Published: June 2020

The ethyl — , ethylene — , propyl — , isopropyl — , butyl — , isobutyl — and t. butyl— bromides, as well as the bromoform and carbon tetrabromide, were photochlorinated in the liquid phase. The number of reaction products obtained is higher than expected and their nature was determined mainly by N.M.R. spectroscopy. Apart from the expected bromochloroalkanes, dichloro — , rearranged bromochloro — and dibro-moalkanes were found. The appearance of these compounds can be best explained by the action of three main effects : decomposition of the beta-bromoalkyl radicals, the so called «vicinal effect » ; intervention of non-classical bridged radicals and intermolecular exchanges of bromine.
Une représentation des involutions cycliques du troisième ordre
Authors: Godeaux Lucien
Published: June 2020

Étude d'une variété représentant une involution cyclique du troisième ordre dans un espace linéaire obtenue en rapportant projective-ment les hypersurfaces cubiques d'un système linéaire appartenant à l'involution, ne passant pas par les axes ponctuels de l'homographie génératrice, aux hyperplans d'un espace linéaire de dimension convenable. Examen de quelques cas particuliers.
Effets de la désoxycorticostérone, du glucagon et de l'insuline, sur le rapport isotopique 13C/12C du C02 respiratoire, chez le rat
Authors: Mosora Florentina , Lacroix Marcel , Pontus Micheline , Duchesne Jules
Published: June 2020

Les auteurs démontrent qu'il n'est possible de mettre nette¬ ment en évidence l'effet de la désoxycorticostérone, du glucagon et de l'insuline, sur le δ13C caractérisant le CO2 exhalé par le rat normalement nourri, que si celui-ci a subi l'ablation des glandes ou la destruction des cellules qui provoquent la sécrétion de l'hormone en cause.

L'interprétation qualitative des effets observés, dans ces conditions, est liée au fait de l'influence variable des hormones considérées, dans le déterminisme de la formation du CO2.
Remarques sur les congruences W
Authors: Godeaux Lucien
Published: June 2020

Construction de deux suites de Laplace associées dans l'espace à cinq dimensions à une congruence W.
Sur les surfaces de rotations projectives
Authors: Marcus Froim
Published: June 2020

On démontre quelques propriétés des surfaces de rotation projective, c'est-à-dire des surfaces telles que les lignes de Darboux et les lignes de Segre correspondantes forment un réseau de Koenigs.
Sur les variétés isotropes de défaut et de codimension 2 et qui sont munies d'une structure presque cosymplectique
Authors: Rosca Radu
Published: June 2020

Fn+ 1,n étant un espace pseudo-euclidien réel de signature (ni + l,n) on étudie l'inclusion x : [formule] d'une variété isotrope [formule] dont le défaut et la codimension sont égales à 2. L'espace normal ponctuel [formule] est déterminé par deux vecteurs isotropes réels [formule] et est contenu dans l'espace tangent ponctuel [formule]. On munit [formule] d'une structure presque cosymplectique [formule] qui est telle que le champ de Reeb ξ est un vecteur temporel, et [formule]. La forme métrique fondamentale [formule] est exprimée par [formule] où [formule] est une forme quadratique parahermitienne permutable avec [formule].

Une inclusion x, telle que les deux secondes formes quadratiques qui lui sont associées soient conformes à [formule] est dénommée une inclusion conformément parahermitienne (i.c.p.). Une pareille inclusion est non substantielle (dans le sens de K. Yano et B. Y. Chen [1]), et elle met en évidence une 1-forme a qui est une section différentiable locale de l'espace cotangent [formule]. Si a est fermée, alors la parenthèse de Lagrange pfaffienne l(a) par rapport à [formule] de a est incompressible sur [formule]. Différentes autres considérations sont faites concernant une i.c.p.
Numerical solution of a mixed problem for a polyvibrating equation of D. Mangeron
Authors: Leung Kin Vinh , Oguztöreli Mehmet N.
Published: June 2020

In this paper we construct numerically the solution of a mixed problem for a polyvibrating equation of D. Mangeron.
Biomasse, contenu en eau et productivité d'une pessière en Haute-Ardenne. Comparaison avec une hêtraie
Authors: Devillez Freddy , Jain T. C. , Jouret M. F. , Lebrun Jean , Marynen T. , Renard Ch.
Published: June 2020

Biomass, water content and productivity of a 39 years old spruce stand have been studied during August 1966 at the «Plateau des Tailles» (Ardenne belge, 595 m above sea level) in a spot located close to the beechwood we previously dealed with. Total dry biomass was 166,4 t/ha ; out of this, the underground material is taking a part of 22,98 %. The annual productivity reachs 12,4 t/ha/year with a photosynthetic efficiency of 1,32 % if calculated on the basis of the total radiant energy throughout the year. According to the effective assimilation period only, the photosynthetic efficiency reachs a value of 1,88 %. These results are discussed with special reference to the values obtained in a beechwood.
Une propriété caractéristique des congruences pseudo-sphériques
Authors: Backes F.
Published: June 2020

Les congruences pseudosphériques sont caractérisées par le fait que les normales aux nappes focales engendrent des congruences doublement stratifiables.
Tests de générateurs pseudo-aléatoires
Authors: Devillers Raymond , Dumont J. J. , Latouche Guy
Published: June 2020

In computers, pseudo-random numbers are usually generated through a linear congruential sequence.

Coveyou and MacPherson [1] propose a test of the randomness of n-uples, Dieter [2] proposes another test for the pairs ; both are theoretical tests.

These are described and applied to some generators.

Arithmetic routines handling integer numbers without limitation of size have been developped to implement the first test, they are outlined in the paper.
Recherches sur la structure des points de diramation d'une surface algébrique multiple (septième note)
Authors: Godeaux Lucien
Published: June 2020

Exposé d'une méthode pour déterminer la structure d'un point de diramation de troisième catégorie. Application à une involution cyclique d'ordre 839.
Fonctions de corrélation dans les systèmes d'Heisenberg anisotropes
Authors: Bagnuls C.
Published: June 2020

Nous démontrons un théorème qui, dans la limite de Weiss, nous permet de limiter à deux équations cinétiques couplées l'étude de l'irréversibilité des systèmes magnétiques anisotropes d'échange et de spin arbitraire, à température finie.
Sur les points unis isolés des involutions cycliques appartenant à une variété algébrique à trois dimensions (troisième note)
Authors: Godeaux Lucien
Published: June 2020

Étude de la structure, dans le cas général, d'un point uni isolé d'une involution cyclique d'ordre premier appartenant à une variété algébrique à trois dimensions. Structure du point de diramation correspondant sur une variété image de l'involution.
Études des systèmes mathématiques possédant la structure complexe. II. Sur l'extension du problème de Goursat pour certains systèmes intégraux fonctionnels concernant une classe d'équations intégro-différentielles non linéaires aux opérateurs polyvibrants
Authors: Krivosheĭn Leonid Evgenʹevich , Mangeron Démètre J. , Oguztöreli Mehmet N. , Voinea Radu P.
Published: June 2020

Les auteurs ont étudié lors de ces dernières années nombre de problèmes concernant les systèmes mathématiques possédant la structure
Assimilation et translocation du 14CO2 chez le froment (Triticum aestivum L.) en fonction de la densité et de la structure du couvert aérien
Authors: Ledent Jean-François
Published: June 2020

Distributions of assimilates at different times after assimilation of 14CO2 shortly after ear emergence of semidwarf spring wheat differing in leaf angle and row width were similar. The differences in leaf angle were obtained with a normal droopy cultivar and a mutant derived from it and characterized by erect upper leaves. Shortly after emergence, flag leaf laminae and spikes (especially glumes, paleas and lemmas) were the main photosynthesizing parts. Their position in the upper levels accounted for the little effect of canopy architecture on their relative importance for photosynthesis. Leaf sheaths and particularly flag leaf sheaths photo-synthesized as much as about one third of their corresponding lamina. Most of the residual radioactivity at maturity was in the grains.
Sur les involutions cycliques n'ayant qu'un nombre fini de points unis de première espèce
Authors: Godeaux Lucien
Published: June 2020

Détermination d'une relation entre le genre géométrique d'une surface algébrique F contenant une involution cyclique d'ordre premier p n'ayant que des points unis de première espèce et celui d'une surface image de l'involution.
Existence et utilisation de surface de section dans certains systèmes dynamiques
Authors: Godart Odon
Published: June 2020

Dynamical systems with a two dimensional hamiltonian of the form : 2H = P2R + P2x + Q2(R,z) = ε2 admit, for ε sufficiently small, solutions combining a rapid oscillation of finite pulsation ω1 with a slow longitudinal oscillation of pulsation of the order of ε. (ThI and II) When the variation of ω1 determined along the line Q = 0 admits only one minimum, for ε small there will exist a surface of section. It is only necessary to calculate trajectories from one crossing to the next to determine the law of transformation of the surface of section in itself and then to know the solution for all values of t. Special angular variables are devised for that purpose.
Sur certains systèmes infinis de quadriques
Authors: Godeaux Lucien
Published: June 2020

Résumé. — Construction d'un système infini de quadriques dépendant de deux paramètres, tel que deux quadriques consécutives se touchent en quatre points caractéristiques pour les deux quadriques.
Des solutions périodiques d'équations différentielles non linéaires
Authors: Turner John Wm.
Published: June 2020

Abstract. — A simple method for calculating the characteristics of time and space oscillating solutions of a non-linear differential equation is developed.
Transformation theory for a lattice model in a uniform field
Authors: Theodosopulu M. , Grecos Alkis P.
Published: June 2020

Abstract. — The collision operator is calculated for a system representing an infinite one-dimensional lattice in a uniform external field. Using its spectral properties we construct the unitary transformation which diago-nalizes the von Neumann operator. We follow the theory developed by the Brussels group in studying the dissipative properties of quantum systems.
Sur diverses expressions du nombre π
Authors: Backès Fernand
Published: June 2020

Résumé. — Une curieuse expression du nombre π est obtenue directement à partir de la série classique de Leibnitz, la convergence pouvant d'ailleurs être améliorée au moyen d'une autre série.
Analysis of the solar spectrum : Results for the range λ 6105.0 -λ 6116.5
Authors: Dingens Paul , Steyaert Herman , Baeck Nicole
Published: June 2020

Abstract. — Applying the method proposed earlier for decomposing the solar spectrum into Gaussian components, the results obtained for the interval λ 6116.5 - λ 6132.0 are given here.

Table I lists 67 components, with their central wavelength, equivalent width, (reciprocal) standard deviation and tentative identification.
Analysis of the solar spectrum : Results for the range λ 6132.0 -λ 6150.0
Authors: Steyaert Herman
Published: June 2020

Abstract. — Applying the method proposed earlier for decomposing the solar spectrum into Gaussian components, the results obtained for the interval λ 6132.0 - λ 6150.0 are given here.

Table I lists 93 components, with their central wavelength, equivalent width, (reciprocal) standard deviation and tentative identification.
Étude cinétique de la synthèse des carbocyanines. I. Aminolyse des sels de ß-ethylthiovinyl-2 cycloammoniums
Authors: Guillaume A. , Bruylants Albert
Published: June 2020

Summary. — Salts of β-ethylthiovinyl cycloammoniums are generated, as stable intermediates, during the synthesis of carbocyanines starting from orthoesters and quaternary salts with activated methyl groups. In order to set up a reaction scheme of this synthesis, reactivity of these intermediates towards nucleophiles was investigated. Therefore, kinetical parameters of the reaction of 2(β-ethylthiovinyl) 1,3,3-trimethyl indoleninium iodide (trans form) with a series of anilines were determined.

The reaction is looked at in acetonitrile at 25 °C. The observed rate constant (κapp.) follows the equation :

[formule]

pointing out the double part played by the anilines (A).
Champs électromagnétiques à rayons intégrables, divergents et sans distorsion
Authors: Leroy Jules
Published: June 2020

The Einstein-Maxwell field equations are considered for a Maxwell field admitting a hypersurface-orthogonal, non-shearing, diverging null eigenvector. The Petrov type D space-times are all determined as well as the spaces for which the two null eigenvectors of the Maxwell field are eigenvectors of the Weyl tensor. A class of Petrov type II solutions is also given.
Automorphismes et semi-espaces de réseaux cristallographiques
Authors: Doignon Jean-Paul , Goovaerts A.
Published: June 2020

Any automorphism of a cristallographical lattice is induced by an affinity. We give an elementary proof for this, and also study semi-spaces for the induced convexity and the segment convexity. E.g., we exhibit finite semispaces in lattices.
Triple collision as un unstable equilibrium
Authors: Waldvogel Jörg
Published: June 2020

The family of trajectories near a triple collision solution in the planar problem of three bodies is investigated by means of linearization in the neighbourhood of the parabolic free fall. The local topological structure of this family is found to be that of a saddle point in the R8. The corresponding stable manifold is the set of all triple collision solutions, whereas the instable manifold is formed by the parabolic solutions.

In important cases of nonzero total energy the family of close encounters is quantitatively described in terms of hypergeometric functions. By means of homothetic transformations the close triple encounters are then related to three-body motion with zero energy and zero angular momentum. In this way almost all close encounters near a homothetic solution can be treated by using a small number of particular solutions of the three-body problem that may be calculated once for all.

In practical examples the first order theory presented here predicts the escape velocity after a close triple encounter with a relative accuracy comparable to the closeness of the encounter.
Subdynamics in the Lee model, I
Authors: De Haan Michel
Published: June 2020

In the framework of the theory of subdynamics introduced by the Brussels group, we construct explicitly and in closed form the whole set of subdynamics for a particular model : the Lee model in the one particle sector. The method presented here can be used for applications to other systems in field theory.
Invariance relativiste de la théorie des champs sur un espace-temps courbe
Authors: Spindel Philippe , Schomblond Christiane , Henneaux Marc
Published: June 2020

A relativistic quantum field theory can be build up on a curved space-time provided with a continuous group of isometries. Large use is made of the Lie derivatives of the field operators, a detailed definition of which is presented in the spinor case.
Influence de la température sur le comportement des systèmes chimiques non linéaires
Authors: Colle P.
Published: June 2020

L'analyse linéaire du comportement du modèle trimoléculaire montre quelle est l'influence de la température sur le nombre d'états stationnaires uniformes, la stabilité et les oscillations éventuelles autour de ces états.

Des précisions au sujet des valeurs critiques des paramètres de bifurcation sont obtenues. La méthode de calcul de perturbations décrite par J. F. G. Auchmuty et G. Nicolis est appliquée pour établir la forme approchée d'une structure spatiale stationnaire.