A new feature extraction method based on clustering for face recognition

Part 13: Feature Extraction - MinimizationInternational audienceWhen solving a pattern classification problem, it is common to apply a feature extraction method as a pre-processing step, not only to reduce the computation complexity but also to obtain better classification performance by reducing the amount of irrelevant and redundant information in the data. In this study, we investigate a novel schema for linear feature extraction in classification problems. The method we have proposed is based on clustering technique to realize feature extraction. It focuses in identifying and transforming redundant information in the data. A new similarity measure-based trend analysis is devised to identify those features. The simulation results on face recognition show that the proposed method gives better or competitive results when compared to conventional unsupervised methods like PCA and ICA

Water scarcity conflicts in a community managed irrigation system in Northern Tunisia: Supporting dialogue and negotiation

Conflict over water resources emerges from complex interactions among biophysical, social, and economic processes operating at multiple scales. The concomitant use of surface and groundwater managed for multiple uses is a classic coping strategy to manage the water scarcity yet a relevant example of such conflict. Managing these resources is thus a dynamic decision-making process involving actors with different perceptions of the situation, who adapt different strategies to satisfy their objectives and interests. This paper presents the results of an effort to address these conflicts through reinforcing the adaptive capacity of different actors to cope with water scarcity in a multi-scale irrigation system. The study site focuses on the irrigated area of Zaouiet Jedidi in Northeast Tunisia. This region is characterized by an intensive irrigated agriculture, mostly through an excessive pumping of groundwater resources. Individual strategies to face the water scarcity are dominating leading to a rapid deterioration of the groundwater resources. Irrigation through individual and informal wells is an example of such strategies. As the demand for agricultural and urban water has concurrently continued to develop, the groundwater has continued to drop. Despite the State's efforts to increase the water supply to the region through the transfer of surface water from the dams of northwestern Tunisia, the overexploitation of groundwater resources exceeded 200 %. A participatory process was implemented to initiate a process of interaction and coordination between the different stakeholders involved in the management of the irrigated area. We analyzed to what extent and by what mechanisms, a participatory problem-solving process can facilitate the emergence of collection action to face the water scarcity.</p

Bioactive Lipids, Antibacterial, Hypoglycaemic, and Antioxidant Potentials of Immature and Mature Vicia faba L. Seeds Cultivated in Tunisia

Both the immature and mature Vicia faba L. seeds are used for human consumption. However, there is a lack of information on the phytochemical composition and the potent biological properties of the immature seeds. The aim of the present study was to establish the profile of bioactive lipids as well as the antibacterial, antioxidant, and α-amylase and α-glucosidase inhibitory capacities of the immature and mature Vicia faba L. seeds. The studied petroleum ether extracts contain different bioactive compounds such as β-sitosterol, lupeol, β-amyrin, α-tocopherol, and γ-tocopherol. The extracts of the immature seeds exhibited higher antioxidant and antibacterial activities than those of mature ones. All tested extracts exerted higher inhibition on α-glucosidase than α-amylase. The immature seeds appeared as promising sources of natural antioxidants, antibacterial compounds, and α-amylase and α-glucosidase inhibitors. Thus, the immature Vicia faba L. seeds have a great potential as functional foods providing health beneficial properties

Bioguided fractionation and isolation of natural inhibitors of advanced glycation end-products (AGEs) from Calophyllum flavoramulum

Advanced glycation end-products (AGEs) are associated with many pathogenic disorders such as Alzheimer’s disease, pathogenesis of diabetes, atherosclerosis or endothelial dysfunction leading to cardiovascular events. Clusiaceae and Calophyllaceae families are rich in compounds like polyphenols which are able to inhibit their formation and are therefore of great interest. Calophyllum flavoramulum Hend. &amp; Wyatt-Sm., a native Malaysian plant, was selected after an anti-AGEs screening conducted on DCM and MeOH extracts from plants belonging to these aforementioned families. In a first study, bioguided fractionation of the MeOH leaf extract of C. flavoramulum afforded amentoflavone, 3-methoxy-2-hydroxyxanthone, 3,4-dihydroxy-tetrahydrofuran-3-carboxylic acid, quercitrin, 3,4-dihydroxybenzoic acid, canophyllol and apetalactone. Amentoflavone and 3-methoxy-2-hydroxyxanthone were found to be very potent (IC50 = 0.05 and 0.06 mM respectively), while anti-AGEs activities of quercitrin and 3,4-dihydroxybenzoic acid appeared as moderately strong (IC50 = 0.5 mM). In a second study, a systematic phytochemical study of the cyclohexane, DCM and EtOAc extracts obtained from the same plant was conducted to isolate the following products: flavoramulone, 6-deoxyjacareubin, rheediachromenoxanthone, 2,3-dihydroamentoflavone and benzoic acid. 3,4-Dihydroxy-tetrahydrofuran-3-carboxylic acid and flavoramulone were isolated for the first time and their structures were identified by means of IR, MS and NMR spectrometries

Assessment of growth hormone gene polymorphism effects on reproductive traits in Holstein dairy cattle in Tunisia

Research to assess the effect of single genes on reproductive traits in bovine species is imperative to elucidate genes' functions and acquire a better perspective of quantitative traits. The present study was undertaken to characterize genetic diversity in the bovine growth hormone (GH) gene in a population of 410 Holstein dairy cows in Tunisia. The analyses were based on single nucleotide polymorphisms, and GH-AluI and GH-MspI detections and genotyping were carried out using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Data were analyzed using a mixed linear model with the MIXED procedure to reveal the possible effect of GH genotypes on reproductive traits. The frequency data of AluI(L//V) and MspI(+//−) alleles were 87.04//12.96 and 70.06//29.94, respectively. The distribution of the frequency of GH genotypes for LL/LV/VV and (−/−)//(+/−)//(+/+) were 77.75//18.59//3.66 and 15.37//29.13//55.50, respectively. The results of the statistical analyses proved that GH-AluI showed a substantial favorable effect on exanimate traits except for the age at first calving; however, only a suggestive effect of GH-MspI on the calving interval (CI) and the days open (DI) was found. The homozygous LL genotype seemed to be advantageous with respect to the CI and the DI compared with LV and VV genotypes. Heterozygous MspI(+/−) cows tended to have a longer CI and DI than MspI(+/+) and MspI(−/−) cows, but the difference was not statistically significant. A significant effect of different GH-AluI–MspI combined genotypes was found on the number of inseminations per conception, the CI and the DI, and the LL/– combined genotype seemed to be associated with better reproductive performance. Based on these results, the LL genotype of the GH locus can be considered to be a favorable genotype for reproductive traits in Holstein dairy cattle, although these findings need to be confirmed by further research before polymorphisms can be used in a marker-assisted selection program.</p

Exploring ways to improve agricultural water management in two Mediterranean irrigated systems: promises of wireless low-tech sensor networks

Unsustainable use of water resources and climate change will exacerbate the already existing tensions on resources, especially in the Mediterranean context. Despite investments in modern, economically and energetically costly equipment, the performance of irrigated agriculture remains below expectations, notably because of inappropriate irrigation practices, due to insufficient knowledge of irrigation actual need and limited use of decision support tools. Access to information at an unprecedented level, via easily accessible low-cost and low-tech sensors, may be a major lever for better identifying achievable performance gains, at different spatial and temporal scales, and for guiding stakeholders towards more sustainable practices. To explore this hypothesis, we have worked on the emergence of such technologies within two Mediterranean irrigated systems (Provence, France, and Cap Bon, Tunisia) facing major water use efficiency issues. Interviews were conducted on each site in order to identify main local needs and constraints that limit sustainable water management, and potential levers to improve irrigation performance. Innovative technological systems (water sensors, automation, Internet of Things networks) have been developed in response and tested in field through a participatory approach. The technologies were then designed to be low energy, low-tech and low-cost, based on the hypothesis that the lack of accessibility – investment and maintenance costs, system readability – of existing equipment was a brake to the dissemination of innovations in the agricultural sector. We believe that the adoption of such technologies could contribute to improve irrigated systems sustainability by playing on several dimensions: promote suitable and sparing water use by improving decision-making; help maintain agricultural production by decreasing input costs; improving water users' working conditions. Generally, accompanying the transition towards more sustainable practices, by providing to the stakeholders keys for better understanding of their system. The performance gains achievable with these innovations, heeding their inherent weaknesses (eg. lower robustness and accuracy), and the potential impacts of their adoption at a larger scale remain to be assessed in an integrated way.</p

Hurler disease (mucopolysaccharidosis type IH): clinical features and consanguinity in Tunisian population

Mucopolysaccharidosis type I (MPS I) was a group of rare autosomal recessive disorder caused by the deficiency of the lysosomal enzyme, alpha -L -iduronidase, and the resulting accumulation of undergraded dematan sulfate and heparan sulfate. MPS I patients have a wide range of clinical presentations, that makes it difficult to predict patient phenotype which is needed for genetic counseling and also impedes the selection and evaluation of patients undergoing therapy bone marrow transplantation