Characterization of human holocarboxylase synthetase activity and specificity

Human Holocarboxylase Synthetase (HCS) transfers the vitamin biotin to the biotin carboxyl carrier protein (BCCP) domains of five biotin-dependent carboxylases. There are two major forms of HCS present in mammalian cells, which differ by 57 amino acids at their N-terminus. Both variants catalyze biotinylation through a two step reaction in which an activated intermediate, bio-5'-AMP, is first synthesized from biotin and ATP. In the second step, the biotin moiety is covalently attached to a specific lysine residue on the carboxylase. The mammalian carboxylases comprise the cytosolic acetyl-CoA carboxylase 1 (ACC1), the outer mitochondrial membrane bound acetyl-CoA carboxylase 2 (ACC2), and the three mitochondrial carboxylases pyruvate carboxylase (PC), 3-methylcrotonyl-CoA carboxylase (MCC) and propionyl-CoA carboxylase (PCC). In order to investigate the HCS reaction mechanism and specificity, both isoforms were recombinantly expressed, purified, and biochemically characterized. The basic mechanistic features of the two HCS variants were investigated using steady state and pre-steady state kinetic methods. The latter methods allow the determination of the rates of bio-5'-AMP synthesis and biotin transfer independent of each other. Both isoforms catalyze the overall reaction similarly and synthesize bio-5'-AMP with a rate of 0.1s-1. Biotin transfer to the BCCP domain fragments of ACC1 and ACC2 carboxylases, to which HCS has continuous access from the cytosol, is slow and saturable. In contrast, biotin transfer to the BCCP domain fragments from the mitochondrial carboxylases PC, PCC and MCC is characterized by rates that are significantly faster and limited by the collision of enzyme and acceptor substrate. The same pre-steady state methods were applied to two biotin ligases from archaea and prokarya, and showed that this collision limited biotin transfer mechanism is widespread among evolutionary domains. The observation of a collision limited reaction emphasizes the role of protein substrate recognition in the biotinylation reaction, and provides a mechanism for establishing a hierarchy among carboxylases that favors mitochondrial substrates. This default hierarchy can be overridden according to cellular demands by modifying the carboxylases' expression. The results support the idea that in the cell one of the mechanisms of biotin-related metabolism regulation relies on HCS specificity to control biotin distribution among carboxylases

Social Housing Allocation: A Problem Structuring approach

The demand for social housing (SH) has emerged all over Europe and it is expo-nentially increasing particularly since the 2008 global economic crisis. This growing temporary housing demand comes from a sector of the population living in the so-called “grey zone”, also known as the ‘in-work poverty’ population. The “grey zone” is composed of individuals in a situation of housing vulnerability [39]: people whose housing needs cannot be met by the market and at the same time who are not eligible to access public housing programs, such as the homeless, internal migrants, city users, single-earner families, the elderly, people subject to eviction, single parents. Typically, the process underpinning the selection of SH projects has focused on re-ducing the SH shortage by providing enough supply. Nowadays, the process of selec-tion of SH projects is no longer simply related to the lack of housing stock but also to the social, economic and cultural changes that currently affect a wide segment of the European population [7, 9, 19]. In this new scenario, the focus of SH policies is shift-ing from the building understood as a product to the people who live in the building. In fact where the human factor is fundamental to target the recipients, in order to pursue the integration of different social groups and the improvement the living con-ditions in the buildings. As the attention now being given to the topic in the interna-tional arena testifies, the scientific community and the market are looking to SH as a key area in which to test new approaches to sustainable design and implementation, taking into account not only the three “consolidated” pillars of sustainability (i. e. environment, society and economy), but also relevant additional dimensions, such as ethics, culture and technology [5]. In this scenario, SH represents a challenge that requires to be made with limited investments and at the same time designed to ensure the reduction of housing cost for users, promoters and managers in the use phase, as well as the achievement of the highest quality standards. The housing cost, including both the rental costs and those of utilities should not exceed 40% of the users income [33]. It is a given fact that sustainable design has, above all, the environmental perfor-mance in terms of building envelope as its object and purpose. Usually, alongside this, the use of renewable energy, eco-friendly materials and technological solutions for the quality of life indoors and the optimal management of water and waste are recognized as integrated quality of the intervention. An aspect that nowadays is con-sidered increasingly important is the ability of real estate transactions to generate and preserve value. Moreover, a key objective of SH is the creation of an "active commu-nity" where people can easily integrate into the urban context. Therefore, it is essen-tial to pay particular attention to the location of the project, its accessibility and prox-imity to services, to all the forms of participation and co-planning that the project can stimulate, to the mix of facilities to be offered (in the individual building and in the neighbourhood), promoting reduced economic and social inequalities and avoiding the creation of social segregation [3]. In this sense, along with the architectural design it is therefore essential to simultaneously undertake the "project of social management" of the intervention, which means predicting the set of actors and actions in the use phase that can ensure their sustainability in terms of the community. In the planning phase it a reference profile of the future community that will ensure a balanced social mix should already be established. However, in the light of recent international environmental protocols for assessing sustainability in construction, such as LEED, SB 100, BREEAM communities, CasaClima Habitat, protocol ITHACA, Lidera, AUDIS [3, 24, 25] it is clear that, if these types of assessments are applied to SH operations, the environmental dimension takes precedence, mostly linked to energy efficiency and the attention to building materials, rather than to the social and economic aspects. Little attention is given to interpersonal sphere of living, or the aptitude of the building for the implementation of specific activities of social inclusion, or to the expected interventions and targeted aid to contrast the difficulties of the future users of social housing. These "non-traditional" aspects for a conventional residence become paramount in an SH intervention. In order to tackle this social challenge, meet the user needs and foster effective means of public/private investment, this research intends to propose a new more tailored and effective approach for the decision making process related to the allocation of public (and private) resources for SH projects. Our research is articulated through an overview of the literature of the field and the analysis of the process of evaluation and selection of the SH interventions actually adopted by a banking foundation, in order to develop specific considerations and contributions on the topic. A large and consolidated amount of recent literature concerning SH problems exists in different fields. Mention can be made of the studies conducted in the spheres of the link between energy and technical aspects [16, 18, 19, 20] the relation between technical aspects and construction costs [8, 10, 11, 13, 28, 37, 40], the evaluation methods of the social retrofitting intervention [31, 2, 4, 17, 26, 32, 35, 36], the quality of life and the reduction of social exclusion [12, 14, 21, 23, 29, 30]. The above mentioned extensive literature highlights the need to understand and decide which SH projects are worth funding, based on technical and social considerations, in order to provide access to housing and related social support for those who need it [26, 38]. Therefore, a consolidated and structured evaluation method able to simultaneously consider all the aforementioned aspects in SH field is still needed. The research presented in this paper begins with the experience of an Italian bank foundation that has been involved in SH projects since 2007. This foundation developed its own assessment methodology to screen large funding requests from social agencies (cooperatives, religious bodies, public administration) wishing to implement SH projects. The methodology consists of three decision-making process stages: 1- A technical evaluation of the buildings in which the SH projects will be hosted is performed. A team according to four main criteria: (i) overall architectural consisten-cy of the building; (ii) economic correctness of the adjustment work planned; (iii) accessibility of the spaces for people with disabilities; and, (iv) flexibility/modularity of the building. These criteria are in turn divided into thirteen sub-criteria; 2- A social evaluation of how the projects intend to provide social support destined for the future beneficiaries (mainly the inhabitants but also the neighbourhood communities) of the SH units is undertaken. A team comprising psychologists, community psychologists and psychotherapists assess all the SH projects according to three main criteria: (i) overall quality of the social support project; (ii) fairness of the financial plan of the social project; and, (iii) possibility to create synergies with cooperatives and social agencies in order to perform social activities. These criteria are subsequently divided into eleven sub-criteria; 3- Criteria weights are assigned and aggregated during the technical and social assessments by a multidisciplinary group of experts in order to obtain a ranking of the projects. This study conceives the above assessment methodology as a Problem Structuring Method (PSM) [1, 15, 22, 27, 34], since it is configured as a flexible and real mechanism for addressing complex problems by representing the situation in a structured manner, as it exhibits many similarities with consolidated and recognised PSMs [27]. Moreover, the aforementioned methodology has the potential to be significantly improved in order to address complex issues characterized by the presence of multiple actors often with different perspectives or objectives and conflicting interests supporting participants’ learning about their own and others’ perspectives, as well as the problematic situation of concern [34, 6]. From this perspective, the research intends to experiment a possible improvement to the Bank foundation’s assessment methodology, exploiting a participative method, based on the use of emerging technologies. ICT could provide spontaneous and voluntary data to be incorporated into a structured method, not only to support the Decision Maker (DM) in the ex-ante phase (with portfolio problems or constructing a tender; with the definition of the architectural, technical and social characteristics of the intervention), but also in itinere and in the ex-post phases, when it will be possible to monitor if the final outcomes meet the initial objectives. The decision- making process related to the SH projects will be structured as follows: - The first level of the decision-making process will directly involve the citizens and the stakeholders with the aim of clarifying the real needs of the beneficiaries of the SH units. In this phase the data will be collected in two ways: “spontaneous data”, via the analysis of social networks data, such as tweets and Flickr data; “voluntary data”, through partially structured and partially open surveys, analysed with specific semantic theories and tools; - The second level of the decision-making process will involve the DM, experts, spe-cific stakeholders operating directly in the SH sector (i.e. the managers of the SH buildings) and the citizens, in order to structure the decision-making model through a series of workshops. In this phase the use of PSM and ICT will be strongly supported by visual representation (3D models). After a pilot test in Italy, the research will continue by performing test planning ac-tivities of the decision-making process in other European Countries

Functional role of PGAM5 multimeric assemblies and their polymerization into filaments.

PGAM5 is a mitochondrial protein phosphatase whose genetic ablation in mice results in mitochondria-related disorders, including neurodegeneration. Functions of PGAM5 include regulation of mitophagy, cell death, metabolism and aging. However, mechanisms regulating PGAM5 activation and signaling are poorly understood. Using electron cryo-microscopy, we show that PGAM5 forms dodecamers in solution. We also present a crystal structure of PGAM5 that reveals the determinants of dodecamer formation. Furthermore, we observe PGAM5 dodecamer assembly into filaments both in vitro and in cells. We find that PGAM5 oligomerization into a dodecamer is not only essential for catalytic activation, but this form also plays a structural role on mitochondrial membranes, which is independent of phosphatase activity. Together, these findings suggest that modulation of the oligomerization of PGAM5 may be a regulatory switch of potential therapeutic interest

Diabetes, an inflammatory process: Oxidative Stress and TNF-alpha involved in hepatic complication

Diabetes mellitus (DM) is a serious and growing worldwide health problem and is associated with se- vere acute and chronic complications that negatively influence both quality of life and survival of affected individuals. It is a heterogeneous deregulation of car- bohydrate metabolism. The liver is a central regulator of carbohydrate homeostasis and releases glucose according to metabolic demands. In the last years, the liver injury has been recognized as a major complica- tion of DM. In fact, evidence suggests that in diabetic patients, the mortality rate due to liver cirrhosis is even higher than that due to cardiovascular disease and it has been suggested that there is a two-fold in- creased risk of liver disease in diabetic patients. Among the different types of diabetes, we analyze type 1 dia- betes mellitus as a chronic disorder and an inflam- matory process, which is also associated with in- creased risk of chronic liver injury. Animal models have contributed extensively to the study of diabetes, and it is well established that administration of a unique dose of streptozotocin (STZ) induces insulin- dependent type 1 diabetes mellitus. We analyzed the contribution of Tumor Necrosis Factor alpha (TNF-α) intracellular pathway and oxidative stress in the de- velopment of apoptosis in the liver of streptozotocin- induced diabetic animals. In this review, we describe the role of upstream mediators of the interaction be- tween TNF-α and its receptor, TNF-R1, by assessing the ability of the in vivo treatment with etanercept (TNF-α blocking antibody) to protect against TNF-α- induced apoptosis. Also, we studied the role of iNOS- induction in the TNF-α-induced liver apoptosis by type 1 diabetes, by treatment of diabetic rats with aminoguanidine (selective iNOS inhibitor), which blocked the induction of apoptosis. Interestingly, iNOS inhibition significantly reduced TNF-α levels, evidencing an interaction between TNF-α and iNOS activity. On the other hand, we found that the ad- ministration of antioxidants/hydroxyl radical scaven- gers (Tempol and Desferal) prevented oxidative stress by reducing the effects of hydroxyl radical production and both lipid peroxidation (LPO) levels and apop- tosis. Taken together, our studies support that, at least in part, the hydroxyl radical acts as a reactive inter- mediate, which leads to liver apoptosis in a model of STZ-mediated hyperglycemia. Conclusion and Future: The relevance of the present review is to provide fur- ther knowledge about the mechanisms which may contribute to the disease process in the liver during the course of an inflammatory process as it is type 1 diabetes. Regulation of hepatic TNF-α levels and oxi- dative stress in the diabetic state could be of thera- peutic relevance for the improvement or delay of the hepatic complications linked to chronic hyperglycemia.Fil: Frances, Daniel Eleazar Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Fisiología Experimental (i); ArgentinaFil: Ingaramo, Paola Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Fisiología Experimental (i); ArgentinaFil: Ronco, Maria Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Fisiología Experimental (i); ArgentinaFil: Carnovale, Cristina Ester. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Fisiología Experimental (i); Argentin

Herpetofauna de la Reserva Paleontológica del Arroyo Toropí, Bella Vista, Corrientes, Argentina

El área del Toropí representa una de las zonas más estudiadas respecto a la megafauna paleontológica (Zurita y Lutz, 2002; Erra et al., 2013). Dada su importancia, el Municipio de Bella Vista, en conjunto con el Instituto de Cultura de la Provincia de Corrientes y la Universidad Nacional del Nordeste, se encuentran trabajando en el desarrollo de una Reserva Paleontológica del Arroyo Toropí (RPAT), con el objetivo de conservar el yacimiento paleontológico, la biodiversidad y riqueza de ambientes naturales actuales (Ordenanza municipal N° 651/07 de la municipalidad de Bella Vista, Corrientes). Además, mediante la sanción de la ley provincial 6165/12, el área del Arroyo Toropí fue declarada “Patrimonio Paleontológico de la provincia de Corrientes”. No existen estudios previos sobre la biodiversidad de la RPAT, es por ello que el presente trabajo tuvo como objetivo elaborar un inventario de las especies de anfibios y reptiles de la RPAT, con el fin de contribuir al conocimiento de la herpetofauna, determinar los ambientes de mayor riqueza de especies y generar información de base que pueda ser utilizada en futuros planes de manejo y conservación de la reserva. Párrafo extraído del texto a modo de resumenFacultad de Ciencias Naturales y Muse

TRIANGULAC[C]IÓN | Il caso del Mercato Legazpi di Madrid

The main contribution of municipal architects to Madrid's Rationalism must be investigated in the construction of public buildings. Markets play a fundamental part among them, thanks to the work of F. J. Ferrero Llusìa, public architect since 1921. With his markets, between 1931 and 1934, it has brought a real change in European industrial architecture in the XIX century. With the premise of hygiene, constructive austerity, structural trueness and the rejection of ornament in favour of pure form, he created a new hypothesis that was characterized by the guiding principles of Rationalism. Awareness of the construction culture of the time, through observation of the details and technical literature linked to the “Mercado Central de Frutas y Verduras” in Madrid, are the conditions for an intervention of conscious restoration. The paper presents a process of slow re-appropriation of the site by the citizens, as an alternative to the current project proposed by the municipality

Changes in soil phosphorus in different forest residue management

We analyze the short term effect of the harvest residues management on the Phosphorus (P) fractions of the soil. Four trials were installed in Northeast Argentina on Vertisols (S1), Mollisols (S2) and Entisols (S3 and S4). In S1 and S2 harvest residues and forest fl oor were either (1) removed (R), (2) retained (RR), 3) burnt (BR), or (4) retained at double the normal quantity (DR). In S3 and S4 harvest residues where (1) removed (WTH), 2) retained (RR) or 3) burnt (BR). Soil samples were obtained at 0-5 cm and 5-10 cm depth layers at 18 (S1), 22(S2, S3) and 10 (S4) months after burnt treatments. P fractions were determined according to Hedley et al. (1982) methods. Soil orders showed different total P: in Mollisols P concentration (S2: 314,3 mg kg-1) tripled those in Entisols (S3 y S4: 118,4 mg P kg-1). Differences were even higher for Organic P (Po): the highest concentration was found in Mollisols (171,4 mg Po kg-1) related to its higher organic matter, and the lowest concentration was in Entisols (44,0 mg Po kg-1). Available P was between 14 mg kg-1 and 25 mg kg-1, enough to satisfy annual demands of forest plantations (Eucalyptus and Pinus). RR and DR did not show changes in the P fractions, although an increase in the P reserves (Po y Pt) could be expected for the middle term, due to the decomposition of the retained/added residues. R or WTH did not affect neither inorganic nor organic P fractions. The most important change was found in BR, where the available P and other mean and highly stable inorganic P fractions increased, due to the ashes; the Po was not modified. The fi re was an instant mechanism to transfer the nutrients from the biomass to the soil.Instituto de SuelosFil: Lupi, Ana Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Suelos; ArgentinaFil: Quintero, César. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias; ArgentinaFil: Boca, Rosa Teresa. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Clima y Agua; ArgentinaFil: Diaz, Diana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Boschetti, Graciela. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias; ArgentinaFil: Aparicio, Jorge Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bella Vista; ArgentinaFil: Ingaramo, Luciana And. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; Argentin

MANEJO DE RESIDUOS DE Eucalyptus grandis Hill ex Maiden EN SITIOS CONTRASTANTES

En la región NE de Argentina existe poca información sobre el impacto que tienen las diferentes alternativas de manejo de residuos de la cosecha forestal sobre las propiedades edáficas. En este estudio se analizó el efecto a corto plazo de sistemas de manejo de residuos de la cosecha de Eucalyptus grandis Hill ex Maiden, sobre la concentración del carbono orgánico total del suelo (COT) y la fracción particulada (COP), su estado estructural y la conductividad hidráulica saturada. El estudio se desarrolló en dos sitios de la Provincia de Entre Ríos, Argentina, en un suelo Aquic Hapluderts (S1) y en un Fluventic Hapludolls (S2). Se aplicaron los siguientes tratamientos: 1. Extracción total de residuos (ER), 2. Conservación de residuos (CR), 3. Quema de residuos-testigo (QR), 4. Doble adición de residuos (DAR). El muestreo de suelos en las profundidades 0-5 cm y 5-10 cm se realizó a los 18 (S1) y a los 22 (S2) meses de aplicar los tratamientos. En el corto plazo, el efecto de los tratamientos dependió del tipo de suelo y de la variable analizada. Los contrastes más importantes se debieron al efecto de las características intrínsecas del suelo sobre el tamaño de los agregados y la conductividad hidráulica saturada. La conservación de residuos no aumentó la concentración de COT ni modificó la calidad de la materia orgánica medida a partir de COP. El suelo Aquic Hapluderts presentó agregados más grandes, más estables y una mayor Ksat en comparación con el Fluventic Hapludolls. En el Aquic Hapluderts se observó una mayor conductividad hidráulica saturada en los tratamientos con conservación de los residuos (DAR y CR), debido a que la cobertura preservaría el sistema poroso en la interfase suelo-atmosfera. El Fluventic Hapludolls fue menos estable y los tratamientos no modificaron significativamente el tamaño de los agregados ni la conductividad hidráulica saturada. Considerando que las características del sitio tienen efectos de corto plazo y las variables respuesta son afectadas de manera diferencial es necesario realizar un monitoreo de los parámetros evaluados para analizar las respuestas y las recomendaciones según el suelo

Depredación de <i>Erythrolamprus poecilogyrus</i> (Serpentes: Dypsadidae) por <i>Lethocerus annulipes</i> (Heteroptera: Belostomatidae)

La chinche de agua gigante Lethocerus annulipes (Herrich-Schaeffer, 1845) es un insecto de hábitos acuáticos perteneciente a la familia Belostomatidae y a la subfamilia Lethocerinae. Los integrantes de esta subfamilia incluyen a las especies de los géneros Benacus, Kirkaldyia y Lethocerus y representan a los heterópteros de mayor tamaño con especies que alcanzan los 120 mm de longitud. Se caracterizan por ser depredadores de una gran variedad de presas como moluscos, crustáceos, insectos, peces y con mayor frecuencia anfibios con escasos registros de depredación en reptiles. Se han publicado numerosos registros de esta especie alimentándose de anuros. Sin embargo, hasta el momento no han sido reportados casos de depredación de esta especie sobre reptiles. En esta comunicación damos a conocer el primer registro de depredación sobre un reptil por parte de L. annulipes. Párrafo extraído del texto a modo de resumenFacultad de Ciencias Naturales y Muse