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Open Journal of Forestry 2022年第4期12卷 408-431页

作者： Steve Nanfack Tassiamba Jean Lagarde Betti Lucie Félicité Temgoua Liliane Rosine Kourogue Armand Wilfried Ndedy Bile alain Rayane mpouam Department of Forestry Faculty of Agronomy and Agricultural Sciences University of Dschang Dschang Cameroon Faculty of Science Department of Biology and Physiology of Plant Organisms University of Douala Douala Cameroon

One of the problems at the root of the poor management of forest resources in Cameroon is the lack of good governance. This study aims to evaluate the governance put in place by the government of Cameroon to ensure better management of Prunus africana. It takes a critical look at the three pillars of forest governance in relation to the management of the resource, which are: policy, legal, institutional and regulatory frameworks (1);planning and decision-making process (2);and finally the implementation, enforcement and compliance of regulations (3). The assessment was conducted using the guide recommended by FAO-PROFOR. Individual and focus group interviews were conducted with stakeholders involved in the P. africana management process. The results in the form of assessment scores revealed poor governance in the management of the resource. This is due to non-compliance with Pillars 2 and 3 on the planning and decision-making process as well as the implementation and enforcement of regulations through weaknesses in the principles of transparency, accountability, the effectiveness of management measures and stakeholder participation. These are the points on which management strategies should be based for better management of P. africana in the production forests of the Adamawa region.

关键词： Forest Governance Prunus africana Stakeholders Pillars Components

Supervised Learning Method: Critical Analysis and Updating of Cubing Rate Formulas for Determining Bark Masses of Prunus africana (Hook. f.) Kalkman (Rosaceae) in Cameroon

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Open Journal of Forestry 2024年第3期14卷 346-368页

作者： Armand Ndedy Bile alain mpouam Benoit Fouadjio Lorette Guedeu Kambale Muhesi Steve Tassiamba Paulette Kouam Eric Wete Marius Ela Michèle Yimga Joseph Ambara Louis Aimé Fono Jean Lagarde Betti Department of Plant Biology Faculty of Science The University of Douala Douala Cameroon Department of Wood and Forest Sciences ISABEE University of Bertoua Bertoua Cameroon Department of Water and Forests Higher Institute of Agronomic Veterinary and Forestry Studies of Butembo Butembo Democratic Republic of Congo Department of Forestry Faculty of Agronomy and Agricultural Sciences University of Dschang Dschang Cameroon Department of Biology and Plant Faculty of Sciences University of Maroua Maroua Cameroon Deutsche Gresellschaft fur Internationale Zusammenarbeit GmbH (GIZ) Bertoua Cameroon Department of Mathematics and Computer Science Faculty of Science The University of Douala Douala Cameroon

The stem barks of Prunus africana are used in the treatment of the benign prostate. Cameroon is one of the important exporters of the barks. Despite the important measures adopted in Cameroon for sustaining its harvesting, some many chalenges still remain. The objective of this work is to refine the forest management parameters in relation to P. africana in the regions of Adamaoua and the South-West by developing a volume rate which makes it possible to estimate the production for a new stem. The work took place in two phases: in the South-West in 2010 and in Adamaoua in 2011. Data collection used the semi-direct method, while the cubing equation was deduced by the multiple linear regression method. Two models for volume estimation and three models for mass prediction were developed. The predictive parameters retained are diameter, height of the bole and thickness of the bark. Results show that the average mass of the dry bark for a given P. africana tree species is 27.55 ± 14.44 kg and this varies according to the site. The strong adjusted coefficient of determination (adjusted R2) observed illustrates the reliability of the proposed models. These models provide a reliable tool that can be adopted as a standard in Cameroon for P. africana.

关键词： Prunus africana Prostate Quota Mass Model Sustainable Management

Stepping up after spinal cord injury:negotiating an obstacle during walking

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Neural Regeneration Research 2025年第7期20卷 1919-1929页

作者： alain Frigon Charly G.Lecomte Department of Pharmacology-Physiology Faculty of Medicine and Health SciencesUniversitéde SherbrookeCentre de recherche du Centre Hospitalier Universitaire de SherbrookeSherbrookeQCCanada

Every day walking consists of frequent voluntary modifications in the gait pattern to negotiate *** spinal cord injury,stepping over an obstacle becomes *** over an obstacle requires sensorimotor transformations in several structures of the brain,including the parietal cortex,premotor cortex,and motor *** information and planning are transformed into motor commands,which are sent from the motor cortex to spinal neuronal circuits to alter limb trajectory,coordinate the limbs,and maintain *** spinal cord injury,bidirectional communication between the brain and spinal cord is disrupted and animals,including humans,fail to voluntarily modify limb trajectory to step over an ***,in this review,we discuss the neuromechanical control of stepping over an obstacle,why it fails after spinal cord injury,and how it recovers to a certain extent.

关键词： biomechanics locomotion neurophysiology obstacle negotiation spinal cord injury

Some Remarks on Korn Inequalities

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Chinese Annals of Mathematics,Series B 2018年第2期39卷 335-344页

作者： alain damlamian Dedicated to Philippe G. Ciarlet on the occasion of his 80th birthda

A recent joint paper with Doina Cioranescu and Julia Orlik was concerned with the homogenization of a linearized elasticity problem with inclusions and cracks(see[Cioranescu, D., Damlamian, A. and Orlik, J., Homogenization via unfolding in periodic elasticity with contact on closed and open cracks, Asymptotic Analysis, 82, 2013, 201–232]). It required uniform estimates with respect to the homogenization parameter. A Korn inequality was used which involves unilateral terms on the boundaries where a nopenetration condition is imposed. In this paper, the author presents a general method to obtain many diverse Korn inequalities including the unilateral inequalities used in [Cioranescu, D., Damlamian, A. and Orlik, J., Homogenization via unfolding in periodic elasticity with contact on closed and open cracks, Asymptotic Analysis, 82, 2013, 201–232]. A preliminary version was presented in [Damlamian, A., Some unilateral Korn inequalities with application to a contact problem with inclusions, C. R. Acad. Sci. Paris, Ser. I,350, 2012, 861–865].

关键词： Korn domains Korn-Wirtinger domains Unilateral Korn inequality

Pfaffians and Representations of the Symmetric Group

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Acta Mathematica Sinica,English Series 2009年第12期25卷 1929-1950页

作者： alain LASCOUX CNRS IGM Universite Paris-Est

Pfaffians of matrices with entries z[i, j]/（xi ＋ xj）, or determinants of matrices with entries z[i, j]/（xi - xj）, where the antisymmetrical indeterminates z[i, j] satisfy the Pliicker relations, can be identified with a trace in an irreducible representation of a product of two symmetric groups. Using Young＇s orthogonal bases, one can write explicit expressions of such Pfaffians and determinants, and recover in particular the evaluation of Pfaffians which appeared in the recent literature.

关键词： Pfaffians symmetric group representations

A non-ideal solution theory for the mechanics and electrochemistry of charged membranes

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npj Computational Materials 2022年第1期8卷 1365-1378页

作者： alain Boldini Maurizio Porfiri Center for Urban Science and Progress Department of Mechanical and Aerospace EngineeringNew York University Tandon School of Engineering370 Jay StreetBrooklyn11201NYUSA Center for Urban Science and Progress Department of Mechanical and Aerospace EngineeringDepartment of Biomedical EngineeringNew York University Tandon School of Engineering370 Jay StreetBrooklyn11201NYUSA

Understanding how ions and solvent molecules migrate within charged membranes is fundamental for advancing the analysis of biological membranes and the design of energy storage and production *** efforts highlighted a significant interplay between mechanics and electrochemistry in charged membranes,calling for the development of high-fidelity models to describe their ***,we propose a continuum theory of the chemoelectromechanics of charged membranes,accounting for potentially large deformations and non-idealities of the solution permeating the *** demonstrate the potential applications of our theory within the study of ionic polymer *** theory predicts sizeable effects of non-idealities and mechanical deformations,enabling insight into the role of mechanics on solute and solvent transport within charged membranes.

关键词： interaction. theory electrochemistry

The Guianese population of the fire ant Solenopsis saevissima is unicolonial

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Insect Science 2016年第5期23卷 739-745页

作者： alain Lenoir Severine Devers Axel Touchard alain Dejean lRBI Institut de Recherche sur la Biologie de I'lnsecte UMR CNRS 7261 Universite Francois Rabelais 37200 Tours CNRS Ecologie des Forets de Guyane (UMR CNRS 8172) Campus agronomique BP 316 97379 Kourou cedex Universite de Toulouse UPS INP Ecolab 118 route de Narbonne 31062 Toulouse and CNRS Ecolab (UMR-CNRS 5245) 31062 Toulouse France

In this study, conducted in French Guiana, a part of the native range of the fire ant Solenopsis saevissima, we compared the cuticular hydrocarbon profiles of media workers with previous results based on intraspecific aggressiveness tests. We noted a strong congruence between the two studies permitting us to delimit 2 supercolonies extending over large distances （up to 54 kin）, a phenomenon known as unicoloniality. Solenopsis geminata workers, taken as an out-group for cluster analyses, have a very different cuticular hydrocarbon profile. Because S. saevissima has been reported outside its native range, our conclusion is that this species has the potential to become invasive because unicoloniality （i.e., the main attribute for ants to become invasive） was shown at least for the Guianese population.

关键词： biological invasions cuticular hydrocarbons fire ants unicoloniality

Impact of Drops on Non-wetting Biomimetic Surfaces

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Journal of Bionic Engineering 2009年第4期6卷 330-334页

作者： alain Merlen Philippe Brunet Institut d'Electronique de Microelectronique et Nanotechnologie IEMN Universite des sciences et technologies de Lille1UMR CNRS 8520Avenue Poincare BP 6006959652 Villeneuve d'Ascq cedexFrance

We have carried out an experimental study of liquid drop impact on superhydrophobic substrates covered by a carpet of chemically coated *** micro-structure of the surface is similar to some biological ones(Lotus leaf for example).In this situation the contact angle can then be considered as equal to 180 degrees,with no *** to its initial inertia,the drop experiences a flattening phase after it hits the surface,taking the shape of a *** it reaches its maximal lateral extension,the drop begins to retract and bounces *** have extracted the lateral extension of the drop,and we propose a model that explains the *** find a limit initial velocity beyond which the drop protrudes into the nano-wire *** discuss the relevance of practical issues in terms of self-cleaning surfaces or spray-cooling.

关键词： superhydrophobic surfaces drop impact

Atomic-scale structural signature of dynamic heterogeneities in metallic liquids

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npj Computational Materials 2017年第1期3卷 179-188页

作者： alain Pasturel Noel Jakse University Grenoble Alpes CNRSGrenoble INPSIMaPF-38000 GrenobleFrance

With sufficiently high cooling rates,liquids will cross their equilibrium melting temperatures and can be maintained in a metastable undercooled state before *** of undercooled liquids reveal several intriguing dynamic phenomena and because explicit connections between liquid structure and liquids dynamics are difficult to identify,it remains a major challenge to capture the underlying structural link to these *** initio molecular dynamics(AIMD)simulations are yet especially powerful in providing atomic-scale details otherwise not accessible in *** the AIMD-based study of Cr additions in Al-based liquids,we evidence for the first time a close relationship between the decoupling of component diffusion and the emergence of dynamic heterogeneities in the undercooling *** addition,we demonstrate that the origin of both phenomena is related to a structural heterogeneity caused by a strong interplay between chemical short-range order(CSRO)and local fivefold topology(ISRO)at the short-range scale in the liquid phase that develops into an icosahedral-based medium-range order(IMRO)upon ***,our findings reveal that this structural signature is also captured in the temperature dependence of partial pair-distribution functions which opens up the route to more elaborated experimental studies.

关键词： structural dynamic signature

Direct impacts of recent climate warming on insect populations

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Integrative Zoology 2010年第2期5卷 132-142页

作者： Christelle ROBINET alain ROQUES National Institute for Agricultural Research INRA UR633OrléansFrance

Effects of recent climate change have already been detected in many species,and,in particular,in *** present paper reviews the key impacts of global warming on insect development and *** effects of climate change appear to be much more complex than a simple linear response to an average increase in *** can differ between seasons and bioclimatic *** flight periods,enhanced winter survival and acceleration of development rates are the major insect *** response of insects and hosts to warming up might also lead to disruption of their phenological synchrony,but adaptive genetic processes are likely to quickly restore this *** a number of cases,warming results in removing or relocating the barriers that limit present species’*** is also likely to facilitate the establishment and spread of invasive alien ***,knowledge gaps are identified and future research interests are suggested.

关键词： adaptation alien species climate warming phenology range distribution