Preparation and in vitro characterization of lipospheres as a carrier for the cosmetic application of glycolic acid

Lipospheres for the cosmetic delivery of glycolic acid were prepared by the melt method using tristearin as the lipid phase and hydrogenated soybean phosphatidylcholine as the emulsifier. The lipospheres, sized from 5 to 40 micron, contained a rather high glycolic acid loading level probably due to a partial polymorphic modification of the lipid and determined glycolic acid sustained release pattern

Membrane stress is coupled to a rapid translational control of gene expression in chlorpromazine-treated cells

Chlorpromazine (CPZ) is a small permeable cationic amphiphilic molecule that inserts into membrane bilayers and binds to anionic lipids such as poly-phosphoinositides (PIs). Since PIs play important roles in many cellular processes, including signaling and membrane trafficking pathways, it has been proposed that CPZ affects cellular growth functions by preventing the recruitment of proteins with specific PI-binding domains. In this study, we have investigated the biological effects of CPZ in the yeast Saccharomyces cerevisiae. We screened a collection of approximately 4,800 gene knockout mutants, and found that mutants defective in membrane trafficking between the late-Golgi and endosomal compartments are highly sensitive to CPZ. Microscopy and transport analyses revealed that CPZ affects membrane structure of organelles, blocks membrane transport and activates the unfolded protein response (UPR). In addition, CPZ-treatment induces phosphorylation of the translation initiation factor (eIF2α), which reduces the general rate of protein synthesis and stimulates the production of Gcn4p, a major transcription factor that is activated in response to environmental stresses. Altogether, our results reveal that membrane stress within the cells rapidly activates an important gene expression program, which is followed by a general inhibition of protein synthesis. Remarkably, the increase of phosphorylated eIF2α and protein synthesis inhibition were also detected in CPZ-treated NIH-3T3 fibroblasts, suggesting the existence of a conserved mechanism of translational regulation that operates during a membrane stres

The evolutionary conserved BER1 gene is involved in microtubule stability in yeast

In yeast, microtubules are dynamic filaments necessary for spindle and nucleus positioning, as well as for proper chromosome segregation. We identify a function for the yeast gene BER1 (Benomyl REsistant 1) in microtubule stability. BER1 belongs to an evolutionary conserved gene family whose founding member Sensitivity to Red light Reduced is involved in red-light perception and circadian rhythms in Arabidopsis. Here, we present data showing that the ber1Δ mutant is affected in microtubule stability, particularly in presence of microtubule-depolymerising drugs. The pattern of synthetic lethal interactions obtained with the ber1Δ mutant suggests that Ber1 may function in N-terminal protein acetylation. Our work thus suggests that microtubule stability might be regulated through this post-translational modification on yet-to-be determined protein

On the traces of XPD: cell cycle matters - untangling the genotype-phenotype relationship of XPD mutations

Mutations in the human gene coding for XPD lead to segmental progeria - the premature appearance of some of the phenotypes normally associated with aging - which may or may not be accompanied by increased cancer incidence. XPD is required for at least three different critical cellular functions: in addition to participating in the process of nucleotide excision repair (NER), which removes bulky DNA lesions, XPD also regulates transcription as part of the general transcription factor IIH (TFIIH) and controls cell cycle progression through its interaction with CAK, a pivotal activator of cyclin dependent kinases (CDKs). The study of inherited XPD disorders offers the opportunity to gain insights into the coordination of important cellular events and may shed light on the mechanisms that regulate the delicate equilibrium between cell proliferation and functional senescence, which is notably altered during physiological aging and in cancer

Spring Forage Stash Module to Prevent Forage Crisis on Uruguayan Livestock Systems: An Evaluation Based on Model Simulations

In Uruguay, rangeland cattle production systems support national economy by beef exportation chain and economic inputs to the country. Soil hydric stress episodes results to forage crisis on grassland-based production systems, having high impact on its trajectory and leaving sequels at several farm levels mainly on rearing cattle systems in drought sensitive regions of the country. In that context, the proposal is to create a spring forage stash module, with a simple management rules as a mechanism to build stability to farms and to buffering drought impact. The concept is to differ spring forage (season with low variation coefficient on net primary production) to summer (season with high variation and susceptible to drought stress episodes). This forage stash module is actually started to be implemented in some monitored farms nevertheless, the use of simulation models can project some concrete result generating future possible evolutions for the system. A predator-prey model for extensive livestock systems -called PPGL- was set to understand the impact of that spring forage stash module on animal securing parameter, expressed as the proportion of adult rearing cows maintaining liveweight at summer grazing on a drought scenario. Results suggest that the stashing 10% of the farm surface can save approximatively 70% of rearing cows, even for drought episodes on closing time or in the summer grazing period. Additionally, a linear direct effect was observed between stashing surface on proportion of rearing cows secured. The resulting carrying capacity of the stash forage module is about 800 to 850 kg liveweight / ha on the grazing period, supporting high grazing pressure. Considering those results, the inclusion of a spring forage stash module is a promising tool to generate more resilient livestock production systems

Providing Login and Wi-Fi Access Services With the eIDAS Network: A Practical Approach

The digital identity (or electronic identity) of a person is about being able to prove upon authentication who one is on the Internet, with a certain level of assurance, such as by means of some attributes obtained from a trustworthy Identity Provider. In Europe, the eIDAS Network allows the citizens to authenticate securely with their national credentials and to provide such personal attributes when getting access to Service Providers in a different European country. Although the eIDAS Network is more and more known, its integration with real operational services is still at an initial phase. This paper presents two eIDAS-enabled services, Login with eIDAS and Wi-Fi access with eIDAS , that we have designed, implemented, deployed, and validated at the Politecnico di Torino in Italy. The validation study involved several undergraduate students, who have run the above services with their authentication credentials and platforms and with minimal indications on their usage. The results indicate that the services were beneficial. Several advantages exist both for the users and for the Service Providers, such as resistance to some security attacks and the possibility to adopt the service without prior user registration ( e.g. for short meetings, or in public places). However, some students expressed doubts about exploiting their national eID for Wi-Fi access, mainly in connection with usability and privacy issues. We discuss also these concerns, along with advantages and disadvantages of the proposed services

Supporting authorize-then-authenticate for wi-fi access based on an electronic identity infrastructure

Federated electronic identity systems are increasingly used in commercial and public services to let users share their electronic identities (eIDs) across countries and providers. In Europe, the eIDAS Regulation and its implementation-the eIDAS Network-allowing mutual recognition of citizen’s eIDs in various countries, is now in action. We discuss authorization (before authentication), named also authorize-then-authenticate (AtA), in services exploiting the eIDAS Network. In the eIDAS Network, each European country runs a national eIDAS Node, which transfers in other Member State countries, via the eIDAS protocol, some personal attributes, upon successful authentication of a person in his home country. Service Providers in foreign countries typically use these attributes to implement authorization decisions for the requested service. We present a scenario where AtA is required, namely Wi-Fi access, in which the service provider has to implement access control decisions before the person is authenticated through the eIDAS Network with his/her national eID. The Wi-Fi access service is highly required in public and private places (e.g. shops, hotels, a.s.o.), but its use typically involves users’ registration at service providers and is still subject to security attacks. The eIDAS Network supports different authentication assurance levels, thus it might be exploited for a more secure and widely available Wi-Fi access service to the citizens with no prior registration, by exploiting their national eIDs. We propose first a model that discusses AtA in eIDAS-based services, and we consider different possible implementation choices. We describe next the implementation of AtA in an eIDAS-based Wi-Fi access service leveraging the eIDAS Network and a Zeroshell captive portal supporting the eIDAS protocol. We discuss the problems encountered and the deploy-ment issues that may impact on the service acceptance by the users and its exploitation on large scale

Electronic identification for universities: Building cross-border services based on the eIDAS infrastructure

The European Union (EU) Regulation 910/2014 on electronic IDentification, Authentication, and trust Services (eIDAS) for electronic transactions in the internal market went into effect on 29 September 2018, meaning that EU Member States are required to recognize the electronic identities issued in the countries that have notified their eID schemes. Technically speaking, a unified interoperability platform—named eIDAS infrastructure—has been set up to connect the EU countries’ national eID schemes to allow a person to authenticate in their home EU country when getting access to services provided by an eIDAS-enabled Service Provider (SP) in another EU country. The eIDAS infrastructure allows the transfer of authentication requests and responses back and forth between its nodes, transporting basic attributes about a person, e.g., name, surname, date of birth, and a so-called eIDAS identifier. However, to build new eIDAS-enabled services in specific domains, additional attributes are needed. We describe our approach to retrieve and transport new attributes through the eIDAS infrastructure, and we detail their exploitation in a selected set of academic services. First, we describe the definition and the support for the additional attributes in the eIDAS nodes. We then present a solution for their retrieval from our university. Finally, we detail the design, implementation, and installation of two eIDAS-enabled academic services at our university: the eRegistration in the Erasmus student exchange program and the Login facility with national eIDs on the university portal

Meat and milk production from grass. Effect of stocking rate and mineral nitrogen fertilisation on animal performance and nitrogen cycle.

De nos jours, la production agricole est soumise à certaines restrictions avec l'objectif de contrôler l’impact environnemental et les volumes de production. Ces restrictions ont entrainé des modifications du niveau d'intensification de la production. En ce qui concerne l’élevage des ruminants, le niveau d'intensification est défini par le chargement (animaux/ha) et la fertilisation minérale (kg/ha). La réforme de la Politique Agricole Commune (PAC) en 1992 a instauré des « méthodes de production agricole compatibles avec les exigences de la protection de l'environnement ainsi que l'entretien de l'espace naturel » (Règlement (CEE) N° 2078/92 du Conseil du 30 juin 1992, J.O.C.E. N°L 215 du 30/7/92 ; MRW, 1997). La réduction du niveau d'intensification de la production se trouvait parmi ces mesures. En élevage viandeux, elle était encouragée par l'octroi de primes aux éleveurs ne dépassant pas un seuil de chargement de 2 UGB/ha. Ces primes permettaient de compenser la perte de production due à la réduction du niveau d’intensification. De plus, des primes à l'extensification pouvaient être obtenues pour les chargements inférieurs à 1,4 UGB/ha. Ces mesures, conjointement au système des quotas, ont permis de maîtriser aussi le volume de la production à grande échelle. Actuellement, suite au principe du découplage décidé lors de la réforme à mi parcours de l’Agenda 2000 en juin 2003 et qui correspond aux dernières réformes de la PAC, l’octroi de primes n’est plus lié au volume des productions, mais bien à la surface. Chaque exploitant doit disposer de « droits » qu’il doit activer en justifiant les superficies correspondantes. Ces droits sont calculés sur base des superficies et des animaux qui ont donné lieu à un paiement d’aides directes au cours des années de références 2000, 2001 et 2002. Une fois les droits justifiés et un ensemble de conditions appelées « conditionnalité », liées à l’environnement (Directive Nitrate), à la sécurité alimentaire et au bien-être des animaux, respectés, l’exploitant pourra obtenir le «paiement unique». Les Etats Membres peuvent choisir de découpler certaines productions comme c’est le cas pour les vaches allaitantes en Belgique. De plus, les règlements liés à la « Directive Nitrate » ont permis de mieux prendre en compte les effluents d’élevage et ont provoqué une diminution de la fertilisation azotée susceptible de diminuer la production, l’azote étant le premier minéral limitant pour la croissance végétale. Cependant, dans les prairies pâturées, on constate souvent un bilan azoté positif. L’azote en excès est susceptible de sortir du système en étant lessivé sous forme de nitrate avec un risque de pollution environementale. La réduction de l'intensification de la production obtenue soit par une réduction de la fertilisation azotée soit par la réduction du chargement ou les deux facteurs conjugués, peut provoquer une diminution des déjections déposées sur les parcelles et une réduction du bilan azoté. On peut ainsi obtenir une réduction de la pollution des eaux (notamment par les nitrates) ainsi que les émissions des composants azotés volatils (ammoniac et oxyde nitreux). Les résultats d’une série d'essais menés pendant six années consécutives sur des prairies pâturées par les principaux types de spéculation bovine, la vache allaitante, la vache laitière et le taurillon, sont présentés et discutés dans cette thèse. Le fil conducteur des essais a été un protocole semblable dans ces trois spéculations. Ce protocole visait à comparer d'une part, la réduction de 33% de la fertilisation azotée sans réduction du chargement et d'autre part, le rapport entre ces deux systèmes et un système sans apport d'azote minéral. Les paramètres étudiés ont été les performances zootechniques, phytotechniques, le bilan azoté et, pour les spéculations des vaches laitières et des taurillons, les reliquats azotés dans le sol. En plus, dans la spéculation « taurillon », les trois lots soumis au pâturage ont été comparés à un lot engraissé en stabulation

Aplicación del Modelo de una Explotación Ganadera Extensiva (MEGanE) para el estudio de la sensibilidad de la producción ganadera a la amplitud de la variabilidad de la oferta de forraje

La ganadería pastoril es un sistema complejo, donde los modelos de simulación pueden ser útiles para la comprensión de las dinámicas de sus componentes y respuestas. Se realizaron simulaciones trimestrales con el MEGanE (modelo determinístico) introduciéndose un componente estocástico en el parámetro coefClima, factor que modula la cantidad máxima de forraje posible. Se generaron valores aleatorios del coefClima en seis escenarios de variabilidad, ampliando el Desvío estándar. Los resultados zootécnicos y fitotécnicos obtenidos muestran que al aumentar la amplitud de la variabilidad del coefClima aumenta la variabilidad en la respuesta del sistema y disminuyen los valores promedio. La asimetría del sistema es tal que los resultados en los casos "buenos" para la ganancia de peso de los animales no compensan a los "malos". La inclusión del efecto de la variabilidad de parámetros climáticos parece ser un aspecto importante a considerar en el desarrollo de modelos y la realización simulaciones agronómicas.Grazing livestock production is as a complex system where model simulations could be useful tools to enhance our comprehension of the dynamics of it components. Trimestral simulations with the deterministic model MEGanE where performed including a stochastic input. The coefClima parameter is a multiplicative factor modulating the maximum forage production. Random values of coefClima are generated to build scenarios of climate variability, amplifying it Standard deviation. Results show that an increase in the amplitude of the variability of coefClima increases the variability in agronomical outputs and causes a reduction in the average values. There is an asymmetric in which ―good‖ cases cannot compensate for ―bad‖ ones. The inclusion of the effect of variability on climatic parameters per se seems to be an important aspect on agronomical modeling to build production system scenarios.Sociedad Argentina de Informática e Investigación Operativa (SADIO