Mathematical Modeling Describing the Effect of Fishing and Dispersion on Hermaphrodite Population Dynamics

International audienceIn order to study the impact of fishing on a grouper population, we propose in this paper to model the dynamics of a grouper population in a fishing territory by using structured models. For that purpose, we have integrated the natural population growth, the fishing, the competition for shelter and the dispersion. The dispersion was considered as a consequence of the competition. First we prove, that the grouper stocks may be less sensitive to the removal of large male individuals if female population are totally protected. Second, we show that fishing does not disturb the demographic structure of the population. Finally, we prove that female selective fisheries have the potential of drastically reduce reproductive rates. We also prove that male fishing decreases competition and then increases the total population number

eXamine: a Cytoscape app for exploring annotated modules in networks

Background. Biological networks have growing importance for the interpretation of high-throughput "omics" data. Statistical and combinatorial methods allow to obtain mechanistic insights through the extraction of smaller subnetwork modules. Further enrichment analyses provide set-based annotations of these modules. Results. We present eXamine, a set-oriented visual analysis approach for annotated modules that displays set membership as contours on top of a node-link layout. Our approach extends upon Self Organizing Maps to simultaneously lay out nodes, links, and set contours. Conclusions. We implemented eXamine as a freely available Cytoscape app. Using eXamine we study a module that is activated by the virally-encoded G-protein coupled receptor US28 and formulate a novel hypothesis about its functioning

Optimal vaccination strategies for a heterogenous population using multiple objectives: The case of L1 and L2-formulations

The choice of the objective functional in optimization problems coming from biomedical and epidemiological applications plays a key role in optimal control outcomes. In this study, we investigate the role of the objective functional on the structure of the optimal control solution for an epidemic model for sexually transmitted infections that includes a core group with higher sexual activity levels than the rest of the population. An optimal control problem is formulated to find a targeted vaccination program able to control the spread of the infection with minimum vaccine deployment. Both $L_{1}-$ and $L_{2}-$objectives are considered as an attempt to explore the trade-offs between control dynamics and the functional form characterizing optimality. The results show that the optimal vaccination policies for both the $L_{1}-$ and the $L_{2}-$formulation share one important qualitative property, that is, immunization of the core group should be prioritized by policymakers to achieve a fast reduction of the epidemic. However, quantitative aspects of this result can be significantly affected depending on the choice of the control weights between formulations. Overall, the results suggest that with appropriate weight constants, the optimal control outcomes are reasonably robust with respect to the $L_{1}-$ or $L_{2}-$formulation. This is particularly true when the monetary cost of the control policy is substantially lower than the cost associated with the disease burden. Under these conditions, even if the $L_{1}-$formulation is more realistic from a modeling perspective, the $L_{2}-$formulation can be used as an approximation and yield qualitatively comparable outcomes

Lemon grass (Cymbopogon citratus) essential oil as a potent anti-inflammatory and antifungal drugs

Background: Volatile oils obtained from lemon grass [Cymbopogon citratus (DC.) Stapf, Poaceae family] are used in traditional medicine as remedies for the treatment of various diseases.Aims: In the present study, lemon grass essential oil (LGEO) was evaluated for its in vivo topical and oral  antiinflammatory effects, and for its in vitro antifungal activity using both liquid and vapor phases.Methods:The chemical profile ofLGEOas determined bygas chromatography-mass spectrometry analysis revealed twomajor components: geranial (42.2%), and neral (31.5%). The antifungal activity of LGEOwas evaluated against several pathogenic yeasts and filamentous fungi using disc diffusion and vapor diffusion methods.Results: LGEO exhibited promising antifungal effect against Candida albicans, C. tropicalis, and Aspergillus niger, with different inhibition zone diameters (IZDs) (35-90 mm). IZD increased with increasing oil volume. Significantly, higher anti-Candida activity was observed in the vapor phase. For the evaluation of the antiinflammatory effect, LGEO (10 mg/kg, administered orally) significantly reduced carrageenan-induced paw edema with a similar effect to that observed for oral diclofenac (50 mg/kg), which was used as the positive control. Oral administration of LGEO showed dose-dependent anti-inflammatory activity. In addition, topical application of LGEO in vivo resulted in a potent anti-inflammatory effect, as demonstrated by using the mouse model of croton oil-induced ear edema. To our knowledge, this is the first such report to be published. The topical application of LGEO at doses of 5 and 10 mL/ear significantly reduced acute ear edema induced by croton oil in 62.5 and 75% of the mice, respectively. In addition, histological analysis clearly confirmed that LGEO inhibits the skin inflammatory response in animal models.Conclusion: Results of the present study indicate that LGEO has a noteworthy potential for the development of drugs for the treatment of fungal infections and skin inflammation that should be explored in future studies.Keywords: lemon grass; essential oil; antifungal activity; anti-inflammatory effect; citral; aromatherap

X-ray magnetic circular dichroism in (Ge,Mn) compounds: experiments and modeling

X-ray absorption (XAS) and x-ray magnetic circular dichroism (XMCD) spectra at the L$_{2,3}$ edges of Mn in (Ge,Mn) compounds have been measured and are compared to the results of first principles calculation. Early \textit{ab initio} studies show that the Density Functional Theory (DFT) can very well describe the valence band electronic properties but fails to reproduce a characteristic change of sign in the L$_{3}$ XMCD spectrum of Mn in Ge$_3$Mn$_5$, which is observed in experiments. In this work we demonstrate that this disagreement is partially related to an underestimation of the exchange splitting of Mn 2$p$ core states within the local density approximation. It is shown that the change in sign experimentally observed is reproduced if the exchange splitting is accurately calculated within the Hartree-Fock approximation, while the final states can be still described by the DFT. This approach is further used to calculate the XMCD in different (Ge,Mn) compounds. It demonstrates that the agreement between experimental and theoretical spectra can be improved by combining state of the art calculations for the core and valence states respectively.Comment: 8 page

Microencapsulation of ammodaucus leucotrichus essential oil using chitosan/ TPP/vanillin chemical system

A. leucotrichus (Coss. & Dur.) Coss. & Dur., known in Algeria as “Kammûnes-sofi”, is a medicinal plant that finds culinary use by indigenous populations. Among others, it is used against stomach pain, indigestion, diarrhea, vomiting, fever, and to combat high blood pressure. In this work, the essential oil of A. leucotrichus, obtained by steam distillation (3h) from fruits collected in March 2015 from Tassili n'Ajjer, a vast plateau in south-east Algeria (25°30'0" N and 9°0'0" E), was chemically and biologically characterized and thereafter microencapsulated using a chitosan/TPP/vanillin system.A. leucotrichus essential oil microparticles were produced using an atomization/coagulation technique with chitosan as the shell material, sodium tripolyphosphaste (TPP) and vanillin as crosslinking agents. Comparatively to the most used chemical systems, this one presents several advantages since all the raw materials are nontoxic and no organic solvents are required. Moreover, the used microencapsulation process allows the microparticles production in a single step, without having the constrains of the traditionally used oil-in-water (o/w) emulsion based techniques. The adopted procedure comprises the following stages: (1) Chitosan solution (CS) preparation (3.0%, w/v) in acidic medium (acetic acid 3%, v/v); (2) Oil-in-water (o/w) emulsion preparation by emulsifying the essential oil (O) with the chitosan solution at O/CS ratio of 0.025 (v/v) with Tween 80 (emulsifier of HLB=15.0, 1.5%, w/v). The emulsion was homogenized at 11000 rpm during 5 min with a CAT Unidrive X homogenizer; (3) Atomization of the o/w emulsion in a Nisco VarJ30 system (flow rate: 0.3 ml/min) under pressurized nitrogen; (4) Coagulation with TPP (10%, w/v at pH 6.0) followed by vanillin crosslinking (1.0% (w/v), 50ºC at 0.5 ml/min during 2 h). Microparticles were recovered by filtration under reduced pressure, washed with distilled water and stored in the hydrated form.info:eu-repo/semantics/publishedVersio

Measuring organizational readiness for knowledge translation in chronic care

<p>Abstract</p> <p>Background</p> <p>Knowledge translation (KT) is an imperative in order to implement research-based and contextualized practices that can answer the numerous challenges of complex health problems. The Chronic Care Model (CCM) provides a conceptual framework to guide the implementation process in chronic care. Yet, organizations aiming to improve chronic care require an adequate level of organizational readiness (OR) for KT. Available instruments on organizational readiness for change (ORC) have shown limited validity, and are not tailored or adapted to specific phases of the knowledge-to-action (KTA) process. We aim to develop an evidence-based, comprehensive, and valid instrument to measure OR for KT in healthcare. The OR for KT instrument will be based on core concepts retrieved from existing literature and validated by a Delphi study. We will specifically test the instrument in chronic care that is of an increasing importance for the health system.</p> <p>Methods</p> <p>Phase one: We will conduct a systematic review of the theories and instruments assessing ORC in healthcare. The retained theoretical information will be synthesized in a conceptual map. A bibliography and database of ORC instruments will be prepared after appraisal of their psychometric properties according to the standards for educational and psychological testing. An online Delphi study will be carried out among decision makers and knowledge users across Canada to assess the importance of these concepts and measures at different steps in the KTA process in chronic care.</p> <p>Phase two: A final OR for KT instrument will be developed and validated both in French and in English and tested in chronic disease management to measure OR for KT regarding the adoption of comprehensive, patient-centered, and system-based CCMs.</p> <p>Discussion</p> <p>This study provides a comprehensive synthesis of current knowledge on explanatory models and instruments assessing OR for KT. Moreover, this project aims to create more consensus on the theoretical underpinnings and the instrumentation of OR for KT in chronic care. The final product--a comprehensive and valid OR for KT instrument--will provide the chronic care settings with an instrument to assess their readiness to implement evidence-based chronic care.</p

Investigating the Efficacy of Oily Water Treatment at a De-Oiling Facility in the Northern Industrial Center of CINA - Hassi Messaoud: A Statistical Physics Assessment

Environmental protection is becoming a primary objective when choosing processes andtechnologies for treating oily waters resulting from hydrocarbon production. The focus of treatingoily waters is to eliminate contaminants from effluents before discharging them into the receivingenvironment while adhering to discharge standards. Our work aims to analyze the treatment processfor oily waters in the API unit of the North Industrial Center (CINA), which involves a physical–chemical treatment using activated silica and Kurifix. The study aims to improve the treatmentprocess used for oily water treatment to ensure water conservation for reuse. To enhance the CINAHMDoily water treatment process, we created coagulants with different doses (C1–C6) using sodiumsilicate, activated silicate (sodium silicate + sulfuric acid), distilled water, Kurifix, and an oxygenscavenger while measuring pH, HC (hydrocarbon), and SS (suspended solids) levels. Coagulationand flocculation processes were used to remove suspended solids and hydrocarbons from the water.The results show that the coagulant used reduces suspended matter and hydrocarbon content andincreases pH. The best treatment is achieved with a coagulant prepared with distilled water, 5%sodium silicate, and 2% sulfuric acid. The optimal dose of coagulant is 16 ppm. Automatic dosingprovides better efficiency than manual dosing. The study recommends continuous verification ofchemical preparation and injection, periodic cleaning of settling tanks, and monitoring of oily waterentering the station

Chemical profile and bioactive properties of the essential oil isolated from Ammodaucus leucotrichus fruits growing in Sahara and its evaluation as a cosmeceutical ingredient

Ammodaucus leucotrichus is a medicinal plant commonly used in Algeria by the indigenous populations, especially due to its therapeutic effects. In this context, the aim of the present study was to chemically characterize the essential oil of A. leucotrichus fruits (EOALF) growing in Algerian Sahara, and to evaluate its bioactive properties (antimicrobial, antioxidant and anti-inflammatory). Considering the interest of the cosmetic industry for natural ingredients, and taking into account the obtained biological properties, the essential oil was also evaluated by incorporation in a base cosmetic (cream). The essential oil was extracted with a yield of 2.58 ± 0.17%, being perilla aldehyde identified as the main component, accounting for 85.6% of the total composition. Concerning the tested bioactivities, EOALF presented antioxidant potential, a strong anti-inflammatory activity, and was effective against the tested microbial strains (Staphylococcus aureus, Eschericia coli and Pseudomonas aeruginosa), being S. aureus the most sensitive bacteria. After incorporation in a base cosmetic, the developed formulation was able to preserve the EOALF bioactivities along 28 days under storage. The obtained results, with relevance for the strong-anti-inflammatory activity, pointed out the interest to exploit this essential oil as a cosmeceutical ingredient in the cosmetic industry.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Program PT2020 for financial support to CIMO (UID/AGR/00690/2013), S.A. Heleno (SFRH/ BPD/101413/2014) and P. Costa (SFRH/BPD/101413/2014). This work was also financially supported by Project POCI-01-0145-FEDER- 006984–Associate Laboratory LSRE-LCM funded by FEDER through COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT and project NORTE-01-0145-FEDER-000006, supported by Norte Portugal Regional Operational Program (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF).info:eu-repo/semantics/publishedVersio

Phase II trial of temsirolimus for relapsed/refractory primary CNS lymphoma

Purpose: In this phase II study (NCT00942747), temsirolimus was tested in patients with relapsed or refractory primary CNS lymphoma (PCNSL). Patients and Methods: Immunocompetent adults with histologically confirmed PCNSL after experiencing high-dose methotrexate-based chemotherapy failure who were not eligible for or had experienced high-dose chemotherapy with autologous stem-cell transplant failure were included. The first cohort (n = 6) received 25 mg temsirolimus intravenously once per week. All consecutive patients received 75 mg intravenously once per week. Results: Thirty-seven eligible patients (median age, 70 years) were included whose median time since their last treatment was 3.9 months (range, 0.1 to 14.6 months). Complete response was seen in five patients (13.5%), complete response unconfirmed in three (8%), and partial response in 12 (32.4%) for an overall response rate of 54%. Median progression-free survival was 2.1 months (95% CI, 1.1 to 3.0 months). The most frequent Common Toxicity Criteria ≥ 3° adverse event was hyperglycemia in 11 (29.7%) patients, thrombocytopenia in eight (21.6%), infection in seven (19%), anemia in four (10.8%), and rash in three (8.1%). Fourteen blood/CSF pairs were collected in nine patients (10 pairs in five patients in the 25-mg cohort and four pairs in four patients in the 75-mg cohort). The mean maximum blood concentration was 292 ng/mL for temsirolimus and 37.2 ng/mL for its metabolite sirolimus in the 25-mg cohort and 484 ng/mL and 91.1 ng/mL, respectively, in the 75-mg cohort. Temsirolimus CSF concentration was 2 ng/mL in one patient in the 75-mg cohort; in all others, no drug was found in their CSF. Conclusion: Single-agent temsirolimus at a weekly dose of 75 mg was found to be active in relapsed/refractory patients with PCNSL; however, responses were usually short lived