bluuebunny/crossref_metadata_2025 huggingface dataset:
AFM Characterization of Temperature Effect on the SU-8 Mechanical and Tribological Properties
Authors: Pustan Marius , Birleanu Corina , Voicu Rodica , Muller Raluca
Published: March 2022

This study presents the effect of temperature on the mechanical and tribological properties of SU-8 polymer. The temperature of investigated samples increasing during testing and the variation of mechanical and tribological properties were monitored. The samples for tests were SU-8 hard baked at different temperatures. The hard bake temperature changes the mechanical and tribological properties of polymers. The aim of this research work is the reliability design improvement of SU-8 microstructures from electro-thermally actuated devices where a thermal gradient produces the softening and modification of SU-8 behavior. As a function of the hard baked temperature, different mechanical and tribological properties were experimentally determined using the atomic force microscopy (AFM) technique. The mechanical properties of interest are the modulus of elasticity and hardness. The investigated tribological properties involve the adhesion and friction forces. The modulus of elasticity and hardness decrease if the operating temperature increases based on the thermal relaxation of material and their viscoelastic behavior. The adhesion force between AFM tip and investigated samples increases if the operating temperature increases, respectively. The same evolution was experimentally observed in the case of friction force. Moreover, for the same testing temperature, the modulus of elasticity and hardness increase, and the adhesion and friction forces decrease if the SU-8 is hard baked at high temperature.
Editorial of the Psych Special Issue “Computational Aspects, Statistical Algorithms and Software in Psychometrics”
Authors: Robitzsch Alexander
Published: March 2022

Statistical software in psychometrics has made tremendous progress in providing open source solutions (e [...]
Venezuelan Evangelical Digital Diaspora, Pandemics, and the Connective Power of Contemporary Worship Music
Authors: Mora Fernando Adolfo , García Martínez Enrique
Published: March 2022

During 2020–2021, the COVID-19 pandemics exacerbated the use of digital communication tools for the general population as well as for migrant and diasporic communities. Due to social distancing requirements, church activities had to be suspended or restricted, therefore, local congregations and denominations had to incorporate social media as part of their regular worship channels in an unprecedented way. At the same time, these new spaces opened an opportunity for diasporas to reconnect with their churches back home, and to participate in digital worship projects. In this paper, we study the case of the digital worship collective Adorando en Casa (AeC), which was started at the onset of the pandemics, producing several crowdsourced original musical compositions, uploaded in popular social media sites, and distributed via messaging apps. We focus on the reasons for participation of Venezuelan musicians and singers from different regions in the country, and from the large diaspora of Venezuelan Evangelicals. Additionally, we analyze the characteristics, structure, and theology of some of the songs recorded, to show how the concept of a digital diasporic spiritual consciousness is powerfully expressed through worship music.
Religious “Bubbles” in a Superdiverse Digital Landscape? Research with Religious Youth on Instagram
Authors: Novak Christoph , Haselbacher Miriam , Mattes Astrid , Limacher Katharina
Published: March 2022

Religious activities are no longer confined to local religious communities, but are increasingly taking place online. In that regard, social media is of particular importance for young believers that connect with their peers via platforms such as Instagram. There are conflicting views on the functioning of social media platforms: they are either conceptualized as superdiverse spaces, in which social boundaries can be overcome, or as resulting in separate bubbles that foster exclusive exchanges between like-minded people sharing certain characteristics, including religious affiliation. This article assesses online religious activities based on qualitative research involving 41 young, urban, religious Instagram users of different faiths. We demonstrate how young believers’ interactions on social media produce thematically bound content bubbles that are considerably homogeneous when it comes to religion, but superdiverse in other areas. Religious activities online often have an affirmative effect on religious belonging. This is especially true for young people that perceive themselves in a minority position and search for like-minded people online. We have found that religious content bubbles are clustered around religious traditions. Interreligious exchange (e.g., between Christians and Sikhs) is largely absent, whereas intrareligious boundaries (e.g., between Lutherans, Catholics, and Pentecostals) become blurred. This suggests that differences within religious traditions are losing significance in a digitalized world, while interreligious boundaries remain.
Construction Progress and Aviation Flight Test of BDSBAS
Authors: Gao Weiguang , Cao Yueling , Liu Cheng , Lu Jun , Shao Bo , Xiong Shuai , Su Chengeng
Published: March 2022

As an important part of the BeiDou global navigation satellite system (BDS-3), the BeiDou satellite-based augmentation system (BDSBAS) aims to provide a high-integrity navigation service for users in China and its surrounding areas. At present, BDSBAS has completed the preliminary construction of the system and formed the single frequency (SF) augmentation service. The paper introduces the composition and working process of BDSBAS, and expounds the solution and performance evaluation methods of the BDSBAS SF service. Tests based on a general aviation aircraft were carried out at Caihu Airport in Shenyang, China, which simulated the aircraft’s take-off and landing operation during the approach phase and the transition flight operation during the en-route phase. On this basis, the BDSBAS SF service performance was analyzed and evaluated. The horizontal positioning errors of the three flight tests are 1.62, 1.27, and 1.49 m, respectively, and the vertical positioning errors are 4.38, 4.30, and 4.04 m, respectively. In the first two tests, the APV-I availability and continuity of the service reach 100%. In the last test, a receiver false alarm event occurred, resulting in an APV-I availability and continuity of 99.993% and 99.989%, respectively. The event was confirmed to be caused by some aviation environmental factors and was not related to the system service. No integrity events occurred during the tests. The test results show that the positioning accuracy, availability, and integrity of the BDSBAS SF service meet the APV-I level requirements of the ICAO standards, which preliminarily illustrates the ability of BDSBAS to be used in the field of civil aviation.
Assessing the Accuracy and Potential for Improvement of the National Land Cover Database’s Tree Canopy Cover Dataset in Urban Areas of the Conterminous United States
Authors: Pourpeikari Heris Mehdi , Bagstad Kenneth J. , Troy Austin R. , O’Neil-Dunne Jarlath P. M.
Published: March 2022

The National Land Cover Database (NLCD) provides time-series data characterizing the land surface for the United States, including land cover and tree canopy cover (NLCD-TC). NLCD-TC was first published for 2001, followed by versions for 2011 (released in 2016) and 2011 and 2016 (released in 2019). As the only nationwide tree canopy layer, there is value in assessing NLCD-TC accuracy, given the need for cross-city comparisons of urban forest characteristics. Accuracy assessments have only been conducted for the 2001 data and suggest substantial inaccuracies for that dataset in cities. For the most recent NLCD-TC version, we used various datasets that characterize the built environment, weather, and climate to assess their accuracy in different contexts within 27 cities. Overall, NLCD underestimates tree canopy in urban areas by 9.9% when compared to estimates derived from those high-resolution datasets. Underestimation is greater in higher-density urban areas (13.9%) than in suburban areas (11.0%) and undeveloped areas (6.4%). To evaluate how NLCD-TC error in cities could be reduced, we developed a decision tree model that uses various remotely sensed and built-environment datasets such as building footprints, urban morphology types, NDVI (Normalized Difference Vegetation Index), and surface temperature as explanatory variables. This predictive model removes bias and improves the accuracy of NLCD-TC by about 3%. Finally, we show the potential applications of improved urban tree cover data through the examples of ecosystem accounting in Seattle, WA, and Denver, CO. The outputs of rainfall interception and urban heat mitigation models were highly sensitive to the choice of tree cover input data. Corrected data brought results closer to those from high-resolution model runs in all cases, with some variation by city, model, and ecosystem type. This suggests paths forward for improving the quality of urban environmental models that require tree canopy data as a key model input.
Mining Cross-Domain Structure Affinity for Refined Building Segmentation in Weakly Supervised Constraints
Authors: Zhang Jun , Liu Yue , Wu Pengfei , Shi Zhenwei , Pan Bin
Published: March 2022

Building segmentation for remote sensing images usually requires pixel-level labels which is difficult to collect when the images are in low resolution and quality. Recently, weakly supervised semantic segmentation methods have achieved promising performance, which only rely on image-level labels for each image. However, buildings in remote sensing images tend to present regular structures. The lack of supervision information may result in the ambiguous boundaries. In this paper, we propose a new weakly supervised network for refined building segmentation by mining the cross-domain structure affinity (CDSA) from multi-source remote sensing images. CDSA integrates the ideas of weak supervision and domain adaptation, where a pixel-level labeled source domain and an image-level labeled target domain are required. The target of CDSA is to learn a powerful segmentation network on the target domain with the guidance of source domain data. CDSA mainly consists of two branches, the structure affinity module (SAM) and the spatial structure adaptation (SSA). In brief, SAM is developed to learn the structure affinity of the buildings from source domain, and SSA infuses the structure affinity to the target domain via a domain adaptation approach. Moreover, we design an end-to-end network structure to simultaneously optimize the SAM and SSA. In this case, SAM can receive pseudosupervised information from SSA, and in turn provide a more accurate affinity matrix for SSA. In the experiments, our model can achieve an IoU score at 57.87% and 79.57% for the WHU and Vaihingen data sets. We compare CDSA with several state-of-the-art weakly supervised and domain adaptation methods, and the results indicate that our method presents advantages on two public data sets.
Cooperative Obstacle Avoidance for Multiple UAVs Using Spline_VO Method
Authors: Peng Mingzhu , Meng Wei
Published: March 2022

In order to solve multiple unmanned aerial vehicle (UAV) dynamic collision avoidance, a cooperative obstacle avoidance algorithm considering UAV’s kinematic constraints has been developed. In the proposed algorithm, the useful information of UAVs is screened out by a Heartbeat information filtering mechanism and fused by the user datagram protocol (UDP) communication method, which improves communication performance among UAVs. In addition, the velocity obstacle (VO) method combined with cubic uniform B-spline curve is used to avoid obstacles and generate smooth paths, which can be applied to practical scenes. Finally, dynamic and static obstacle avoidance simulations are carried out to verify the effectiveness of the proposed algorithm.
Phytochemical and Nutritional Profile Composition in Fruits of Different Sweet Chestnut (Castanea sativa Mill.) Cultivars Grown in Romania
Authors: Ciucure Corina Teodora , Geana Elisabeta-Irina , Sandru Claudia , Tita Ovidiu , Botu Mihai
Published: March 2022

Chestnut (Castanea sativa Mill.), a valuable fruit crop, is cultivated in small areas in Romania, mostly in the west, where the moderate continental climate has a slight Mediterranean influence. This work aims to investigate the bioactive characteristics (total polyphenols, total flavonoids and antioxidant activity), individual polyphenolic composition, phytochemical and nutritional HRMS screening profiles, sugar and mineral composition of six sweet chestnut cultivars, namely ‘Marsol’, ‘Maraval’, ‘Bournette’, ‘Précoce Migoule’ and ‘Marissard’ grown at Fruit Growing Research—Extension Station (SCDP) Vâlcea, in Northern Oltenia, Romania. Fruit samples were collected in two consecutive years, in order to study the impact of genetic variability between cultivars and the influence of the different climatic conditions corresponding to different cultivation years. Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) allow the discrimination between the sweet chestnut fruits harvested in different years and different sweet chestnut cultivars. Analytical investigations revealed that sweet chestnut cultivars grown in Romania show similar bioactive, phytochemical and nutritional composition to cultivars grown in the large European chestnut-producing countries, indicating the high adaptation potential of the chestnut in the temperate continental zone with small Mediterranean influences characteristic of the southwestern area of Romania.
A Framework for Rapid Robotic Application Development for Citizen Developers
Authors: Panayiotou Konstantinos , Tsardoulias Emmanouil , Zolotas Christoforos , Symeonidis Andreas L. , Petrou Loukas
Published: March 2022

It is common knowledge among computer scientists and software engineers that ”building robotics systems is hard”: it includes applied and specialized knowledge from various scientific fields, such as mechanical, electrical and computer engineering, computer science and physics, among others. To expedite the development of robots, a significant number of robotics-oriented middleware solutions and frameworks exist that provide high-level functionality for the implementation of the in-robot software stack, such as ready-to-use algorithms and sensor/actuator drivers. While the aforementioned focus is on the implementation of the core functionalities and control layer of robots, these specialized tools still require extensive training, while not providing the envisaged freedom in design choices. In this paper, we discuss most of the robotics software development methodologies and frameworks, analyze the way robotics applications are built and propose a new resource-oriented architecture towards the rapid development of robot-agnostic applications. The contribution of our work is a methodology and a model-based middleware that can be used to provide remote robot-agnostic interfaces. Such interfaces may support robotics application development from citizen developers by reducing hand-coding and technical knowledge requirements. This way, non-robotics experts will be able to integrate and use robotics in a wide range of application domains, such as healthcare, home assistance, home automation and cyber–physical systems in general.
Coupling X-ray Absorption and Raman Spectroscopies to Characterize Iron Species in a Karst Pedosedimentary Record
Authors: Giannetta Beatrice , Cassetta Michele , Oliveira de Souza Danilo , Mariotto Gino , Aquilanti Giuliana , Zaccone Claudio
Published: March 2022

The identification of iron (Fe) forms throughout a sediment sequence was investigated by X-ray Absorption Near Edge Spectroscopy (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) at the Fe K-edge, paired with Raman micro-spectroscopy. The contribution of different organic and inorganic Fe-bearing compounds was quantified by Linear Combination Fitting (LCF) carried out on both XANES and EXAFS spectra. Fe-XANES showed that the Fe(II)/Fe(III) ratio of different Fe-bearing minerals in sediments can be quantified with reasonable accuracy. The main Fe species detected were ferrihydrite, goethite, hematite, clay minerals (smectite, illite, nontronite), and Fe(III)-organic matter (Fe(III)-OM). A more accurate quantification of ferrihydrite was possible with LCF conducted on Fe-EXAFS spectra. With the exception of hematite, the concentration of these mineral species does not have a clear trend with depth, probably because water infiltration caused continuous Fe reduction and oxidation cycles in these sediments. From an analytical perspective, Fe oxide compounds can be difficult to identify or distinguish unless multiple techniques are used. X-ray diffraction (XRD; previous work) and Raman spectroscopy turn out to be not particularly useful in identifying ferrihydrite, while they are best suited for a broad mineralogical analysis that requires integrative spectral studies for an accurate Fe speciation. In detail, XANES and EXAFS allowed for the detection of Fe-bearing clay minerals and a more refined identification of Fe species, including Fe(III)-OM. Thermal analysis was useful to confirm some mineralogical components observed using both XRD (data previously published) and Raman spectroscopy (e.g., goethite, todorokite). In conclusion, this study underlines how a multi-technique approach is required to investigate peculiar environments such as karst pedosequences.
Eco-Friendly Synthesis of Silver Nanoparticles Using Pulsed Plasma in Liquid: Effect of Surfactants
Authors: Niu Yubiao , Omurzak Emil , Cai Rongsheng , Syrgakbek kyzy Dinara , Zhasnakunov Zhanarbek , Satyvaldiev Abduraim , Palmer Richard E.
Published: March 2022

Silver (Ag) nanoparticles were successfully prepared by using the in-liquid pulsed plasma technique. This method is based on a low voltage, pulsed spark discharge in a dielectric liquid. We explore the effect of the protecting ligands, specifically Cetyl Trimethylammonium Bromide (CTAB), Polyvinylpyrrolidone (PVP), and Sodium n-Dodecyl Sulphate (SDS), used as surfactant materials to prevent nanoparticle aggregation. The X-Ray Diffraction (XRD) patterns of the samples confirm the face-centered cubic crystalline structure of Ag nanoparticles with the presence of Ag2O skin. Scanning Transmission Electron Microscopy (STEM) reveals that spherically shaped Ag nanoparticles with a diameter of 2.2 ± 0.8 nm were synthesised in aqueous solution with PVP surfactant. Similarly, silver nanoparticles with a peak diameter of 1.9 ± 0.4 nm were obtained with SDS surfactant. A broad size distribution was found in the case of CTAB surfactant.
The Negative Photoconductivity of Ag/AgO Grown by Spray-Pyrolysis
Authors: de Paiva Aline Bastos , Vargas Luis Miguel Bolaños , da Silva Matheus José , Rodrigues Ariano De Giovanni , Soares Demétrio A. W. , Peres Marcelos Lima , de Godoy Marcio Peron Franco
Published: March 2022

The main goal of this work is to provide a general description of the negative photoconductivity effect observed in Ag/AgO films grown by the spray-pyrolysis technique. X-ray diffractograms display hybrid films with high texturized AgO and metallic Ag phases. Scanning electron microscopy images show small Ag particles on the surface. Due to its surface nature, X-ray photoelectron spectroscopy revealed the predominance of the metallic character of Ag 3d spectra as compared to Ag2+. Negative photoconductivity with photoresponse in the order of seconds is observed under several wavelengths of excitation. We found that the amplitude of the negative photoresponse is strongly dependent on the optical absorbance and enhanced by surface plasmon resonance. The low-cost technique employed and the special features regarding negative photoconductivity provide an exciting platform for developing optical-electronic devices with low power consumption.
Diagnostic Value of Neutrophil-to-Lymphocyte Ratio, Lymphocyte-to-Monocyte Ratio, and Platelet-to-Lymphocyte Ratio in the Diagnosis of Erythema Nodosum Leprosum: A Retrospective Study
Authors: Tanojo Natalia , Damayanti  , Utomo Budi , Ervianti Evy , Murtiastutik Dwi , Prakoeswa Cita , Listiawan Muhammad
Published: March 2022

Erythema nodosum leprosum (ENL) is an acute immune complex-mediated condition of the dermis, subcutaneous tissue, and other tissues seen in patients with multibacillary (MB) leprosy, causing severe impairment to patients’ quality of life. To date, there is no standard diagnostic criteria for ENL. We aimed to study the diagnostic value and accuracy of Neutrophil-to-Lymphocyte ratio (NLR), Lymphocyte-to-Monocyte ratio (LMR), and Platelet-to-Lymphocyte ratio (PLR) in diagnosing ENL. This is an analytic retrospective study with a cross-sectional design that describes the distribution and clinical characteristics of all newly diagnosed MB patients of Dr. Soetomo General Hospital Surabaya in the years 2018–2020. NLR, LMR, and PLR were calculated for all patients, and a receiver operating characteristic curve (ROC) was generated to identify the cut-off points. Among a total of 182 patients with MB leprosy, 22 cases (12.09%) were reported with ENL. WBC, neutrophils, monocytes, and thrombocytes showed a positive correlation with the incidence of ENL, but not lymphocytes. The NLR cut-off point for the diagnosis of ENL was 4.99 (sensitivity 86.4%, specificity 82.5%, accuracy 82.97), while that of PLR was 237.46 (sensitivity 63.6%, specificity 73.1%, accuracy 71.98%). LMR had poor sensitivity and specificity levels of 50% and 28.7%, with cut-off point of 2.28 and accuracy of 31.32%. These results suggest that NLR and PLR could be potential biomarkers for the diagnosis of ENL.
Variations in Daily Maximum Areas and Longitudinal Widths of Solar Coronal Holes in 2017–2020
Authors: Riehokainen Alexandr , Smirnova Victoria , Solov’ev Alexander , Tlatov Andrey , Zhivanovich Ivan , Al-Hamadani Firas , Strekalova Polina
Published: March 2022

We considered coronal holes as a manifestation of the large-scale magnetic field of the Sun. The main goal of this work was to study the variations in the largest areas and longitudinal widths of solar coronal holes observed daily in the polar and mid-latitude zones on a time scale of 984 days. Statistical methods of fast Fourier transform (FFT), wavelet transform, and empirical mode decomposition (EMD) were used to detect periodicity in the variations of the considered parameters. Long-term variations in the daily measured areas and longitudinal widths of the largest solar coronal holes with periods of 8–9, 13–15, and 26–29 days were detected in three zones of the Sun: polar (north and south) and equatorial. The obtained periods are most clearly visible at the equatorial zone. In the polar zones the period of 8–9 days has a weak amplitude. We interpreted variations with periods of 8–9, 13–15, and 26–29 days as a rotation of the six-, four-, and two-sector structure of the large-scale solar magnetic field.
Genetic Relatedness, Antibiotic Resistance, and Effect of Silver Nanoparticle on Biofilm Formation by Clostridium perfringens Isolated from Chickens, Pigeons, Camels, and Human Consumers
Authors: Ahmed Heba A. , El Bayomi Rasha M. , Hamed Rehab I. , Mohsen Rasha A. , El-Gohary Fatma A. , Hefny Ahmed A. , Elkhawaga Eman , Tolba Hala M. N.
Published: March 2022

In this study, we determined the prevalence and toxin types of antibiotic-resistant Clostridium perfringens in chicken, pigeons, camels, and humans. We investigated the inhibitory effects of AgNPs on biofilm formation ability of the isolates and the genetic relatedness of the isolates from various sources determined using RAPD-PCR. Fifty isolates were identified using PCR, and all the isolates were of type A. The cpe and cpb2 genes were detected in 12% and 56% of the isolates, respectively. The effect of AgNPs on biofilm production of six representative isolates indicated that at the highest concentration of AgNPs (100 µg/mL), the inhibition percentages were 80.8–82.8%. The RAPD-PCR patterns of the 50 C. perfringens isolates from various sources revealed 33 profiles and four clusters, and the discriminatory power of RAPD-PCR was high. Multidrug-resistant C. perfringens isolates are predominant in the study area. The inhibition of biofilm formation by C. perfringens isolates was dose-dependent, and RAPD-PCR is a promising method for studying the genetic relatedness between the isolates from various sources. This is the first report of AgNPs’ anti-biofilm activity against C. perfringens from chickens, pigeons, camels, and humans, to the best of our knowledge.
Choroidal Thickness in Correlation with Axial Length and Myopia Degree
Authors: Muhiddin Habibah Setyawati , Mayasari Andi Ratna , Umar Batari Todja , Sirajuddin Junaedi , Patellongi Ilhamjaya , Islam Itzar Chaidir , Ichsan Andi Muhammad
Published: March 2022

Background: Myopia is a condition in which the visual images come to a focus in front of the retina of the eye. This disease is a major cause of visual disability, which presents in 108 million persons globally. Purpose: This study aims to determine the relationship between the degree of myopia, the axial length, and the choroidal thickness (CT). Methods: This is an observational analytical study that made use of a cross-sectional design. A total of 59 participants with refractive errors underwent treatment at Hasanuddin University Hospital and 116 eyes were measured and analyzed. The choroidal thickness was measured using the Enhance Depth Imaging OCT (EDI-OCT) tool, which is divided into nine observational areas. Furthermore, all data obtained were compared using statistical analysis, such as the one-way ANOVA and Pearson correlation test (p < 0.05). Results: There was a significant relationship between the choroidal thickness with axial length (p < 0.05) and myopia degrees (p < 0.05). Conclusions: The thickness of the choroid decreases with an increase in the axial length and degree of myopia, which further indicates that the higher the myopia degree, the thinner the choroidal vasculature.
En agriculture, s'endetter... ?
Authors: Aubert Didier , Bompard Jean-Pierre , Desbrosses Bernard , Léon Yves , Postel-Vinay Gilles , Rio Patrick
Published: March 2022

Surveys in several French departements aim at evctluating the effects of farm credit policies. For each farm in the sample, data from statistical surveys, the so-called structural surveys of the ministry of Agriculture, were paired with data on loans granted by the Credit Agricole Banks.

For the 1970 to 1979 period, distribution of loans to farms appears in clear agreement with the objectives of agricultural policy, particularly through the strenghtening of a shrinking group of high productive farms. This does not preclude the existence, in certain regions and types of farm, of cases where loans had no apparent effects on farm production. The generai income crisis reveals that certain groups of farms face an uncertain future and, in many cases, the main use of loans is to fill the gaps in inadequate monetary incomes.

In the long term, increases in farm production took place under conditions of permanent inequalities in credit distribution. Some well sized farms now experience serious monetary difficultes. It is however small farms, with little or no debts, which silently continue to disappear in large numbers.
"Priorité à l'agriculture" et sélectivité
Authors: Aubert Didier , Bompard Jean-Pierre , Desbrosses Bernard , Léon Yves , Postel-Vinay Gilles , Rio Patrick
Published: March 2022

After a period of rapid development, the loans given in the seventies by the Credit Agricole system only increased at the same rate as the whole ofthe loans to the French economy. Within Credit Agricole 's total operations, loans to farmers are relatively declining but those loans to farmers benefit morefrom subsidized interest rates. Subsidization is now mostly concentrated on certain types of loans for starting farmers and modernization. An evaluation ofthe effects of recent reforms in this subsidization is presented on the basis of surveys in several French departements.
Pratiques traditionnelles et rationalité économique, l'exemple de l'affouage
Authors: Fortier Agnès
Published: March 2022

Traditional practices and economical rationality : the case of wood-logging.

When free wood-logging was most likely to be at its end, new economical and social trends brought this old user law into vogue. If money has been probably acting as the main motive for this comeback, formulation given by the loggers emphasizes the traditional nature of a practice which has to bear up against some critics. Beside money-making, free wood-logging is conveying into modem society some values which hardly express themselves in the rational field of occupational work ; there in lies the difficulty to give a statement on a practice denying the antithesis between work and leisure.
Impact des pratiques et des politiques agricoles sur l'environnement
Authors: Mahé Louis-Pascal , Rainelli Pierre
Published: March 2022

Les pratiques agricoles font maintenant subir à l'environnement des dommages importants. Non seulement la capacité productive à long terme est menacée mais des risques sérieux pour la santé humaine sont aussi créés par la pollution liée aux consommations intermédiaires comme les nitrates. Le développement agricole de ces dernières décennies a aussi des conséquences plus ou moins réversibles sur le milieu naturel. La banalisation du paysage et de la flore et la disparition de certaines espèces sont là pour en témoigner.

Un cadre analytique est proposé pour mettre en évidence les facteurs économiques de la pollution agricole en soulignant le rôle de l'intensification. Celle-ci a été stimulée par la croissance économique en général qui aboutit à aggraver le décalage entre l'optimum collectif et les pratiques observées. Le rôle du soutien des prix agricoles dans le processus d'intensification est souligné, en montrant comment le prix de la terre a joué le rôle de levier. Il est suggéré en conclusion que ni l'abandon du soutien des prix ni des taxes sur les inputs ne peuvent à eux seuls résoudre le problème de la pollution agricole. Ils peuvent cependant y contribuer.
Rente et profit en matière d'exploitation des ressources halieutiques
Authors: Boude Jean-Pierre , Morisset Michel , Revéret Jean-Pierre
Published: March 2022

Rent and profit in matter of halieutic resources management.

In regard to matter of management of living aquatic resources most theoretical writings relating to fishing economics refer to the notion of rent for calling monetary surplus brought out by the production activities. This paper attends to define the notion of rent and of profit in matter of halieutic resources management by the light of attainments of the different schools of thaught. This allows to give a better answer to the questions asked from the economists in matter of management of renewable resources.
Un modèle d'offre régional de sous-produits agricoles
Authors: Réquillart Vincent
Published: March 2022

A model of regional by-products supply.

From a technological point of view, prospects of industrial valorisations of ligno-cellulosic products are important. In this paper we first present specificities of supply of by-products. The market appears to be an oligopoly which implies a price higher than the marginal cost. We also show the dilemna farmers are facing, namely : to sell by-products in order to increase the income in a short term with the risk of a decline of future incomes, due to a loss offertility, or to incorporate by-products. A simple theoretical model presents this dilemna. The application of this model is difficult because of a lack of data.

In a second part, we present a model of regional supply of by-products , allowing an analysis supply of industrial plants. The model allows to take into account some keys factors, namely supply caracteristics including risk, constraints of soil fertility maintenance, problems of harvesting transportation and storage of products. An example of utilisation of this model is presented.
L'effet d'irréversibilité en économie de l'environnement
Authors: Amigues Jean-Pierre
Published: March 2022

The irreversibility effect in environment economy.

Decisions of developing natural zones often involve dramatic alterations of the environment. When the development is irreversible and its expected benefits uncertain, it may be profitable to postpone the décision in order to make use of further information opportunities. In this case, conservation of the environment exhibits a specific positive value, the so-called "quasi option value" even if risk neutrality of the décision maker is assumed.
La crise financière de l'agriculture canadienne
Authors: Debailleul Guy , Erhensaft P.
Published: March 2022

Cet article vise à relier la manifestation des symptômes aigus des difficultés financières de certaines catégories d'agriculteurs à la détérioration chronique de la structure du capital agricole, pour tenter d'élaborer une typologie des exploitations agricoles sous stress financier. En mettant en évidence l'influence de la taille de l'entreprise et de sa spécialisation dans la fréquence des situations de crise, les auteurs cherchent à montrer que le niveau d'organisation des marchés selon les différentes productions constitue un élément important de la fragilité relative des exploitations agricoles. En conclusion les auteurs s'interrogent sur les impacts possibles de cette crise financière sur l'évolution à moyen terme du secteur agricole et sur son mouvement de concentration.
La planification agricole sous Gorbatchev. La nouvelle logique de rationalisation et décentralisation économiques en action
Authors: Pouliquen Alain
Published: March 2022

La réforme impulsée par M. Gorbatchev a modifié, en mars 1986, la méthode de planification des livraisons agricoles à l'Etat. Pour chaque exploitation ou district et région, on évalue des indicateurs : potentiel productif et rendement normatif.

Les autorités cherchent à corriger ainsi la distribution inégalitaire des ressources résultant de la pratique antérieure de "planification du niveau atteint".

Cette rationalisation implique des relations hiérarchiques dans l'administration territoriale. La décentralisation devrait être facilitée par le dépassement des normes de livraison, sous l'effet de stimulants économiques renforcés et diversifiés. Cette réforme vise aussi à instaurer un modèle dual où "impôt en nature" et régulation marchande seraient bien séparés.

Les dirigeants des exploitations ou districts qui se trouvaient privilégiés par l'ancienne méthode chercheront à mettre la réforme en échec, à travers ses failles. Son succès dépend donc de la capacité du pouvoir à créer une dynamique sociale favorable à la méthode de "planification normative". L'enjeu de la réforme agricole est crucial : le pouvoir imposera-t-il cette restructuration radicale ("perestroïka") de l'ordre social, tout en préservant l'essentiel du système de l'économie administrée, une des bases de cet ordre ?
Villes et campagnes en Chine
Authors: Aubert Claude
Published: March 2022

Les réformes de l'agriculture chinoise, et particulièrement la décollectivisation achevée au début des années 80, ont amorcé une nouvelle vague de migrations paysannes vers les cités et les petites villes. À la situation antérieure, caractérisée par la stagnation du mouvement d'urbanisation, l'involution du développement agricole et l'aggravation du sous-emploi en agriculture, a succédé un progrès authentique en ce qui concerne la croissance des villes nouvelles (spécialement celles de petite taille), l'amélioration de la productivité agricole et la création de nombreux emplois non-agricoles dans les campagnes.

Toutefois, de grosses incertitudes planent sur cette nouvelle situation. Il n'est pas certain que le formidable essor des entreprises rurales non-agricoles de ces cinq dernières années se poursuive encore longtemps. Par conséquent, des migrations massives vers les grandes cités seront quasi inévitables si ultérieurement les contrôles des mouvements de population sont assouplis. Le modèle même du "mode de développement à la chinoise" est également mis en question maintenant que le dynamisme des entreprises familiales de type capitaliste rivalise dans les campagnes avec T'économie socialiste" des entreprises collectives.
Les producteurs allemands face à la restriction de l'offre
Authors: Zeddies J. , Heim B.
Published: March 2022

Les producteurs allemands face à la restriction de l'offre. La CEE a imposé au secteur laitier allemand une réduction sensible de ses livraisons, mais la réglementation nationale a permis d'en modérer l'impact. L'article décrit la façon dont les producteurs ont adapté leur système de production aux nouvelles contraintes. Il évalue les différentes solutions possibles : la diminution des achats d'aliments et du nombre de vaches a été le moyen le plus accessible de respecter la réglementation.

Les primes aux abandons de production n'ont pas eu un effet considérable à cause des réticences des producteurs. Mais la RFA a mis en place, dès le début, un système de location des quotas lié au sol : louer des quotas supplémentaires est encore un moyen de croissance, et la meilleure alternative pour les exploitations laitières efficaces.

Les autres alternatives, notamment en productions bovines, sont peu rentables. Et pourtant, la production laitière allemande s'est vu imposer de nouvelles réductions de livraison en 1987. Les auteurs donnent les résultats d'un modèle qui montre que des ajustements rationnels au niveau de l'exploitation passent par la poursuite de la croissance de la productivité et des rendements, une plus grande attention portée à la composition du lait et une gestion soigneuse de l'alimentation et de son coût.
Spécialisation régionale et efficacité de l'agriculture
Authors: Bonnieux François
Published: March 2022

Cet article présente une synthèse d'un ensemble de travaux sur les disparités régionales. Il est tout d'abord l'occasion de présenter une typologie départementale en sept orientations de production : céréales - grandes cultures, légumes-fruits-horticulture, vin, polyculture, hors-sol, bovin-viande, lait. Elle permet une représentation simplifiée de la géographie agricole française au début des années quatre-vingt.

La typologie est un instrument pertinent pour expliquer le niveau de production de l'agriculture. Elle est en effet prise en compte explicitement par le biais de variables indicatrices, dans une fonction de production à quatre facteurs : consommations intermédiaires, capital, terre, travail. L'estimation d'une forme de type translog à partir d'une coupe départementale centrée sur 1980, montre la forte substituabilité des facteurs de production, sauf la terre et le capital qui sont complémentaires. La détermination des demandes dérivées de facteurs permet de mettre l'accent sur l'élasticité par rapport à leur prix, ainsi que sur l'élasticité de la demande de facteurs primaires par rapport au prix des consommations intermédiaires.

La dernière partie est centrée sur la liaison entre orientation de production et efficacité. Elle s'appuie sur une interprétation des variables indicatrices du modèle en termes de productivité totale des facteurs. Les classes de la typologie peuvent, toutes choses égales par ailleurs, être classées par efficacité croissante, des orientations lait et viande bovine à l'orientation céréales-grandes cultures. L'introduction du niveau d'éducation des agriculteurs permet enfin d'expliquer partiellement cette hiérarchie des systèmes départementaux.
Freiner l'intensification en limitant l'emploi des intrants spécifiques ?
Authors: Bidaux A. , Gantner U.
Published: March 2022

Une politique de renchérissement du prix des intrants spécifiques est étudiée en Suisse afin de freiner l'intensification des systèmes de production et de résoudre les problèmes d'environnement et de surplus que rencontre l'agriculture aujourd'hui. Le but de ce travail est d'en examiner l'impact réel, cela aussi bien sur le fonctionnement des exploitations que sur le secteur agricole pris dans son ensemble. Les premiers résultats nous montrent qu'une telle politique est réaliste.

Une politique de renchérissement du prix des intrants spécifiques mènera :

— à un développement plus rapide d'une agriculture "douce" et plus autonome face à l'emploi des intrants spécifiques ;

— à moyen et long terme, à de faibles modifications de l'offre suisse de produits agro-alimentaires (la productivité d'une agriculture plus respectueuse de l'environnement sera aussi soumise au progrès bio-technologique). Mais cette stabilisation de la production ainsi que la substitution de l'offre actuelle par des produits plus "naturels" auront des effets bénéfiques du point de vue de la régulation des marchés agro-alimentaires ;

— à une élévation généralisée des frais de production des exploitations agricoles induite par :

- un engagement relativement plus important de travail ;

- des investissements à réaliser pour l'acquisition d'une mécanisation adaptée ;

- le prélèvement de taxes sur les intrants spécifiques si cette solution est retenue ;

- une baisse significative mais momentanée des rendements si un contingentement des intrants spécifiques est mis en place.

Cependant une utilisation plus nuancée des produits phytosanitaires ne pourra être atteinte que dans le cadre d'une réglementation (légale ou contractuelle).
Disparités régionales des prix des produits alimentaires
Authors: Robin Jean-Marc
Published: March 2022

L'analyse secondaire des statistiques publiées par l'INSEE fait ressortir la diversité des prix des produits alimentaires entre régions. Une argumentation en termes de coûts de production et de coûts de transports rend assez bien compte de certaines des variations enregistrées. Mais elle ne saurait suffire. Une part non négligeable de celles-ci semble en effet pouvoir s'expliquer par des imperfections de marché : existence d'oligopoles, déséquilibre offre/ demande..., Toutefois, le fait marquant de ce travail reste la remarquable manière avec laquelle ces données, que nous tirons de statistiques non adaptées, se prêtent à l'analyse économique.
Prix industriels et prix alimentaires dans la relation prix-salaires
Authors: Tavéra Christophe
Published: March 2022

L'objet de ce travail est de clarifier la nature des interactions qui relient les salaires nominaux, les prix des produits industriels et les prix des produits alimentaires à partir de données trimestrielles françaises portant sur la période 1970-1986. Plus précisément, il s'agit de mesurer et de comparer les rôles respectifs que jouent les prix industriels et les prix alimentaires à l'intérieur des dynamiques prix-salaires. Pour cela, on analyse les causalités qui relient ces trois variables, tout d'abord dans un cadre bivarié (causalité au sens de Granger et de Pierce-Haugh) puis dans un cadre trivarié à partir d'un modèle vectoriel autorégressif non contraint. Enfin, on compare les effets des prix industriels et des prix alimentaires sur la détermination des salaires.

Deux résultats principaux se dégagent. En premier lieu et conformément aux études antérieures, les prix alimentaires paraissent être déterminés par l'imposition d'une marge sur les coûts. Par ailleurs, si l'on rapproche les élasticités des salaires par rapport aux prix alimentaires et aux prix industriels des poids respectifs qu'occupent ces produits dans le calcul du niveau général des prix, il semble qu'il y ait surajustement des salaires par rapport au poids des prix industriels et sous-ajustement par rapport au poids des prix alimentaires.
Politique agricole commune et évolution de l'avantage comparatif : les produits agro-alimentaires (1973-1983)
Authors: Phan Duc-Loi
Published: March 2022

Cet article analyse l'incidence de la PAC sur les avantages comparatifs des pays membres dans les industries agro-alimentaires. Il y est montré que, définis de manière appropriée, les effets d'avantage comparatif spécifiques à un produit ont constitué le facteur dominant dans la détermination de leurs performances nettes d'exportation, comparés au rôle relativement modeste joué par les facteurs relevant de 1'environnement national, spécifiques à un pays. En second lieu, les gains en terme d'avantage comparatif ont été renforcés par la tendance des gouvernements nationaux à mettre en œuvre une politique de "renationalisation" de la PAC.
Relations dynamiques entre les prix des principaux composants de l'alimentation animale
Authors: Dronne Yves , Tavéra Christophe
Published: March 2022

On utilise la méthode de Caines-Keng-Sethi afin d'analyser les relations dynamiques entre les prix des principaux produits de l'alimentation animale sur le marché de Rotterdam. Les résultats nous suggèrent trois commentaires :

— L'analyse des prix permet de retrouver les relations de substitution ou de complémentarité qui existent ente les diverses matières premières avec des signes conformes à ceux que laissent prévoir les diverses compositions nutritionnelles.

— Le corn-gluten-feed apparaît quant à lui comme un substitut des produits riches en protéines et des produits riches en énergie.

— Enfin, le taux de change dollar/Ecu ne semble avoir une influence significative que sur l'évolution du prix du corn-gluten-feed.
La question de la taille optimale des exploitations : le cas danois
Authors: Kjeldsen-Kragh Soren
Published: March 2022

The question of the optimal farm size : the Danish case.

This article deals with size economies in Danish milk and pig production. Two different methods were used : direct analysis from observed cost-output relationship ; use of a trans-log production function to estimate size elasticities. Both results converge : economies of size are exhausted at a size around 30 cows or 60 sows. But in the biggest farms, the revelation of diseconomies of scale is not obvious.
Remarques sur le village comme cadre de recherches anthropologiques (1955)
Authors: Weber Florence
Published: March 2022

L'étude des phénomènes psycho-sociaux se fonde sur la discrimination prélable à la mesure des moyens dont dispose la recherche. De cette nécessité procède pour une bonne part la faveur dont jouissent les "groupes primaires". Parmi ceux-ci, les villages offrent cette particularité d'avoir constitué pendant des siècles des groupes presque autonomes où toutes les fonctions essentielles étaient satisfaites localement avec un minimum d'échanges externes. Discontinuité spatiale de l'habitat, stabilité résidentielle d'ordre familial, autonomie socio-culturelle permettant encore la subsistance en temps de crise, etc., sont les principaux éléments d'une situation d'inter-connaissance caractéristique. Celle-ci offre à la vie sociale comme à la recherche anthropologique des conditions spécifiques sur lesquelles convergent les efforts de transformation ou de connaissance. D'abord empirique, cette convergence ne peut que gagner à devenir systématique aussi bien sur le plan de l'action sociale que sur celui de la recherche anthropologique et de la définition des instruments de travail.
Les nouvelles technologies en agriculture. Une approche technique et économique
Authors: Bonny Sylvie , Daucé Pierre
Published: March 2022

Après avoir rappelé les principales caractéristiques du processus d'innovation en agriculture et quelle en était jusqu'à présent la logique économique, on a cherché à déterminer les potentialités des innovations techniques majeures qui tendent à se diffuser actuellement, biotechnologies et nouvelles technologies de l'information notamment. Faisant l'hypothèse d'un changement de paradigme technologique, on a conduit une première analyse de son impact sur le secteur agricole : un nouveau modèle technique, basé sur la maîtrise des processus du vivant et sur l'information et correspondant à une certaine inflexion de la logique "productiviste" des décennies précédentes, semble susceptible de se mettre en place.