Probiotic Bacteria as an Healthy Alternative for Fish Aquaculture

One of the problems of the aquaculture industry is the presence of pathogenic microorganisms whose proliferation is enhanced when the healthy quality of the culture systems do not meet comply with physical-chemical-biological parameters. In order to improve these problems, less aggressive alternatives to the environment have been sought. This is why probiotic bacteria are proposed as an alternative to the same systems where they will be applied, since they generate greater interest in not presenting a threat to the ecosystem, favor survival, improve the immune system of organisms and have antibacterial properties against pathogenic bacteria. This chapter reviews current research related to the search for marine probiotics for application in the aquaculture industry. Additionally, we deliver results from our work related to the research and application of probiotics. The reported studies demonstrate the positive effects of marine bacteria for their aquaculture application. The evidences found in our work allow us to conclude that larval survival is favored by the application of probiotics in the use of vectors such as rotifers, artemia and biofilms. However, depending on the species of interest, it is necessary to study the market for the biotechnological application of probiotics, to evaluate the feasibility of its production on a larger scale and its commercial feasibility

Développement d'une réaction d'amidation utilisant le diphénylsilane en tant qu'agent de couplage et d'une réaction de borocyclopropanation photochimique

Ce manuscrit décrit les travaux de doctorat réalisés au sein du laboratoire du Pr. Charette entre 2015 et 2019. Ceux-ci s’inscrivent dans deux thématiques de recherche différentes : le développement de nouvelles stratégies d’amidation et le développement de nouvelles méthodologies de cyclopropanation. La synthèse de liaisons amides est, encore aujourd’hui, un défi pour la communauté chimique. En effet, le développement de méthodologies simples, robustes, économes en atomes, et plus respectueuses de l’environnement reste l’une des priorités de recherche en chimie organique. Afin d’apporter une contribution à ce domaine, une méthodologie de synthèse d’amides a été développée en utilisant le diphénylsilane en tant qu’agent de couplage. Celui-ci est disponible commercialement, stable et peu onéreux. De plus, il ne génère qu’un siloxane et du dihydrogène gazeux en fin de réaction. La méthodologie mise au point a également pu être appliquée à la synthèse d’une série de di- et tripeptides. L’utilisation du motif cyclopropanique n’a cessé de prendre de l’ampleur dans le secteur pharmaceutique. En effet, celui-ci peut influer sur différents paramètres cruciaux dans le développement de molécules biologiquement actives. Le développement de nouvelles méthodologies de cyclopropanation est donc un domaine pertinent. La synthèse de borocyclopropanes est particulièrement intéressante : en effet, ces composés peuvent permettre de créer de la diversité structurale via une fonctionnalisation du boronate. Afin d’obtenir un procédé de synthèse de ces composés simple, robuste et plus « vert », une approche photochimique utilisant la technologie en débit continu a été favorisée. Une réaction de borocyclopropanation photorédox de styrènes a pu être mise au point ; celle-ci est réalisée sous irradiation UV-A en présence de xanthone en tant que photocatalyseur. Les études menées afin d’élucider le mécanisme ont permis de conclure que cette transformation se déroulait selon deux cycles catalytiques photorédox concomitants. Finalement, un nouveau réactif diiodé comportant une fonction ester boronique de pinacol et un groupement triméthylsilyle a été développé afin d’accéder à des cyclopropanes gem-disubstitués. Les bases d’un procédé photochimique UV-visible utilisant ce nouveau réactif ont ensuite pu être établies. Ainsi, le premier exemple d’un gem-borocyclopropyl silane dérivé du styrène a pu être synthétisé.This manuscript describes the work carried out in Pr. Charette’s laboratory between 2015 and 2019. It can be divided into two different topics: the development of new amidation strategies and the development of new cyclopropanation methodologies. Amide synthesis is still a challenge for the scientific community nowadays. Indeed, the development of simple, robust, atom economical and environmental friendly procedures remain one of the research priority in organic chemistry. To contribute to this field, an amide synthesis methodology has been developed by using diphenylsilane as a coupling reagent. The latter is commercially available, stable and cheap. Moreover, only a siloxane and dihydrogen are generated during the reaction. The developed methodology has also been applied to the synthesis of a series of di- and tripeptides. The cyclopropane moiety has been increasingly used in pharmaceuticals. Indeed, this moiety can influence different crucial parameters in the development of bioactive molecules. The development of new cyclopropanation methodologies is therefore a relevant field. Borocyclopropane synthesis is of particular interest: as a matter of fact, these compounds can create structural diversity via boronate functionalization. In order to obtain a user-friendly, robust and greener chemical process, a photochemical approach using continuous flow technology has been favored. A photoredox borocyclopropanation of styrenes has been developed; the latter is carried out under UV-A irradiation with xanthone as a photosensitizer. Mechanistic studies have supported that this transformation proceeds according to two concurrent photoredox catalytic cycles. Finally, a new diiodo reagent bearing a pinacol boronate group and a trimethylsilyl group has been developed to access gem-disubstituted cyclopropanes. The bases of a UV-visible photochemical process using this new reagent have then been established. Thereby, the first example of a gem-borocyclopropyl silane derived from styrene has been synthesized

“Gestión de inventarios para mejorar la rentabilidad de la empresa comercializadora S.O.S Solutions S.A.C, Santa Anita, 2017”

El presente trabajo se desarrolló en la empresa S.O.S Solutions S.A.C., la cual se dedica a la comercialización de artículos de cómputo y sus complementos. El problema esencial que evidenció fue la baja rentabilidad de la empresa y esto es consecuencia a su inadecuada gestión de inventarios originando un mal manejo de los mismos, que dio lugar a inconformidad de los dueños de la empresa. Por esta razón, el presente estudio logró alcanzar el objetivo trazado, que fue el determinar cómo la gestión de inventarios mejora la rentabilidad de la empresa. La presente investigación es de tipo aplicado, para la elaboración del presente estudio se utilizó el método hipotético - deductivo, de diseño cuasi experimental, todo esto desarrollado bajo el enfoque cuantitativo. Para la validación de los instrumentos se recurrió al criterio de los jueces expertos. Asimismo, como se puede evidenciar, para la representación de los datos obtenidos y su interpretación, ha sido de gran aporte el software estadístico SPSS

Synergistic effect of co-exposure to carbon black and Fe2O3 nanoparticles on oxidative stress in cultured lung epithelial cells

BACKGROUND: There is a need to better understand synergism in the biological effects of particles composed of multiple substances. The objective of this study was to determine if the oxidative stress in cultured cells caused by co-exposure to carbon black and Fe(2)O(3 )nanoparticles was significantly greater than the additive effects of exposure to either type of particles alone; and to determine a possible cause for such synergistic effect if one was found. Cultured A549 human lung epithelial cells were exposed to (1) carbon black nanoparticles alone, (2) Fe(2)O(3 )nanoparticles alone, and (3) both types of particles simultaneously. Protein oxidation, lipid peroxidation, and cellular uptake of Fe in these cells were measured after 25 hours of exposure. The reduction of solubilized Fe(3+ )by the carbon black nanoparticles was measured separately in a cell-free assay, by incubating the carbon black and the Fe(2)O(3 )nanoparticles in 0.75 M sulfuric acid at 40°C and measuring the amount of reduced Fe(3+ )at different time points up to 24 hours. RESULTS: Cells exposed to carbon black particles alone did not show protein oxidation, nor did the cells exposed to Fe(2)O(3 )particles alone, relative to the control. However, cells co-exposed to both carbon black and Fe(2)O(3 )particles showed up to a two-fold increase in protein oxidation relative to the control. In addition, co-exposure induced significant lipid peroxidation, although exposure to either particle type alone did not. No significant difference in cellular iron uptake was found between single exposure and co-exposure, when the Fe(2)O(3 )dosing concentration was the same in each case. In the cell-free assay, significant reduction of Fe(3+ )ions by carbon black nanoparticle was found within 2 hour, and it progressed up to 24 hours. At 24 hours, the carbon black nanoparticles showed a reductive capacity of 0.009 g/g, defined as the mass ratio of reduced Fe(3+ )to carbon black. CONCLUSION: Co-exposure to carbon black and Fe(2)O(3 )particles causes a synergistic oxidative effect that is significantly greater than the additive effects of exposures to either particle type alone. The intracellular redox reaction between carbon black and Fe(3+ )is likely responsible for the synergistic oxidative effect. Therefore elemental carbon particles and fibres should be considered as potential reducing agents rather than inert materials in toxicology studies. Acidified cell organelles such as the lysosomes probably play a critical role in the solubilization of Fe(2)O(3). Further research is necessary to better understand the mechanisms

Proceso de selección de proveedores para una empresa comercializadora de vidrios, Lima, 2019

El presente trabajo de investigación tuvo como objetivo principal conocer la situación actual del proceso selección de proveedores en una empresa comercializadora de vidrios debido a que cumplen un rol relevante en la cadena de suministro. Sin los recursos materiales no se puede comercializar los productos, de la misma forma materiales en mal estado ocasionan retrasos y entregas con defectos a los clientes. Para la investigación se fundamentó en trabajos de investigación previa tanto nacional como internacional que guarden relación o cierta similitud con el proceso de selección de proveedores como el uso de metodologías y herramientas que ayuden a optimizar el proceso mencionado. La investigación fue de tipo no experimental y diseño descriptivo. La población y muestra estuvo conformada por los pedidos de planchas de vidrio de tres proveedores durante los meses de Mayo 2018 a Abril 2019. Se dio a conocer la situación del proceso selección de proveedores en la empresa comercializadora de vidrios, que presentó inconvenientes de selección como priorizar proveedores a través del criterio precio, ya que se evidenció preferencias de ese criterio sobre otros como calidad y servicio, siendo los últimos dos importantes y que tienen relación directa con el producto que se brindará a los clientes

Grid impedance estimation for islanding detection and adaptive control of converters

The grid impedance is time varying due to the changing structure of the power system configuration and it can have a considerable influence on the control and stability of grid connected converters. This paper presents an online grid impedance estimation method using the output switching current ripple of a SVPWM based grid connected converter. The proposed impedance estimation method is derived from the discretised system model using two consecutive samples within the switching period. The estimated impedance is used for islanding detection and online current controller parameter adaptation. Theoretical analysis and MATLAB simulation results are presented to verify the proposed method. The effectiveness of the grid impedance estimator is validated using experimental results

UPAYA MENINGKATK AN KERJA SAMA DAN HASIL BELAJAR SISWA PADA MATERI MENEMUKAN PIKIRAN POKOK TEKS MELA L UI METODE CREATIVE PR OBLEM SOLVING (CPS) DI KELAS IV SD N 4 SIJUK UPTD KABUPATEN BELITUNG (Penelitian Tindakan Kelas pada Siswa Kelas IV SDN 4 Sijuk Belitung Tahun Pelajaran 2015/2016 )

Penelitian ini mengangkat judul Upaya M eningkatkan K erja Sama dan H asil B elajar S iswa pada M ateri M enemukan P ikiran P okok T eks melalui C reative P roblem S olving (CPS). Penelitia n ini bertujuan untuk meningkatkan hasil belajar siswa kelas IV SDN 4 Sijuk Belitung kabupaten belitung pada tahun ajaran 2015/2016 dengan jumlah siswa 31 orang. Kemampuan menguasai materi yang masih ren dah serta kurangnya minat siswa terhadap mata pelajaran bahasa Indonesia mengakibatkan rendahnya hasil belajar siswa. Dari permasalahan di atas, fokus penelitian yaitu penggunakaan metode pembelajaran yang kurang tepat mengakibatkan kurangnya kemampuan men guasai materi serta minat siswa terhadap mata pelajaran bahasa Indonesia diakibatkan cara belajar yang cenderung membosankan. Penelitian yang dilakukan adalah PTK ( Action Research Class Room ) penelitian tindakan kelas ini berlangsung 2 siklus, tiap sikl us terdiri atas beberapa tahap yakni perencanaan,pelaksanaan dan observasi, dan analisis serata refleksi. Instrumen yang digunakan dalam penelitian ini adalah tes tertulis dan lembar observasi. Berdasarkan hasil penelitian dapat disimpulkan bahwa kegiatan pembelajaran dengan menggunakan metode Creative Problem Solving (CPS ) pada mata pelajaran Bahasa Indonesia pokok bahasan Menemukan Pikiran Pokok Teks yang dilakukan di kelas IV SDN 4 Sijuk Kabupaten Belitung Tahun Pela jaran 2015/2016 dapat meningkatkan has il belajar dan kerja sama siswa secara optimal. Hal ini terbukti dari perolehan nilai setiap siklus mengalami peningkatan, pada siklus I lembar kerja peserta didik 64,51 (64,51%) dan siklus II menjadi 84,67 (84,67%) terjadi peningkatan pada skor rata - rata lembar kerja peserta didik siklus I dan siklus II sebesar 20,16 (20,16%) adanya peningkatan hasil belajar siswa dan kerja sama tersebut menggambarkan keberhasilan suatu peneliti. Kata Kunci : Metode Creative Problem Solving (CPS ), hasil belajar dan kerja sama

A unique effect of clonazepam on frontal lobe seizure control

AbstractIn a 16-year-old female, clonazepam (CZP) changed randomly occurring intractable tonic seizures of frontal lobe origin to a few sleep seizures when used as an adjunctive therapy. The significance of this change in the seizure pattern is discussed with an explanation of possible pathophysiologic mechanism

Wide frequency range active damping of LCL-filtered grid connected converters

It can be challenging to guarantee the stability of grids with many converters with LCL filters connected due to the presence of multiple resonances within the system. This paper presents an active damping technique to mitigate multiple resonance effects and harmonics in power converters connected to weak grids. The proposed technique employs grid current and capacitor voltage feedback to achieve active damping for a wide range of multiple resonance frequencies. The effectiveness of the proposed wide frequency active damping and improved controller stability are demonstrated through frequency domain analysis and experimental results for single and parallel grid connected converters

Chemical Interactions and Cytotoxicity of Terpene and Diluent Vaping Ingredients

Vaping devices have risen in popularity since their inception in 2007. The practice involves using a variety of commercially available devices. Internal heating systems in devices aerosolize e-liquid formulations of complex mixtures including an active ingredient (e.g., THC, CBD, and nicotine), diluents (or cutting agents), solvents, and flavoring agents (e.g., terpenes and aldehydes). The vaping toxicology literature consists of cytotoxicity studies of individual chemicals and commercial formulas. Because of the variation of e-liquid composition, there is a limited understanding of the toxicity of ingredient combinations. This study analyzed the cytotoxic effects after exposure to individual and binary mixtures of a representative terpene (+-R-limonene) and diluent (triethyl citrate) on human lung cell models. Data were analyzed to determine the effects of 97:3 and 80:20% v/v (triethyl citrate/limonene) binary mixtures. BEAS-2B cells, a bronchial epithelial cell, and A549 cells, a type II alveolar epithelial cell, served as models for comparison. LC50 values were calculated and isobolograms were used to assess chemical interactions. Results show that limonene was more cytotoxic than triethyl citrate. Isobolographic analyses confirmed that the 97:3% v/v mixture resulted in an antagonistic chemical interaction. The 80:20% v/v mixture resulted in a similar result. Further testing of different ratios of binary mixtures is needed for chemical interaction screening to inform safety assessments