1,941 research outputs found
Nucleomorph genomes: much ado about practically nothing
The DNA sequence of one of the smallest eukaryotic genomes has recently been finished - that of the reduced nucleus, or nucleomorph, of an algal endosymbiont that resides within a cryptomonad host cell. Its sequence promises insights into chloroplast acquisition, the constraints on genome size and the basic workings of eukaryotic cells
Do apicomplexan parasite-encoded proteins act as both ligands and receptors during host cell invasion?
Apicomplexan parasites are responsible for a wide range of diseases in animals, including humans, in whom Plasmodium species cause the devastating disease malaria. Several recent discoveries now indicate that these intracellular parasites may use a conserved mechanism to infect their host cells by using parasite-encoded proteins as both parasite ligands and receptors anchored to the host cells
How Investors Can (and Can\u27t) Create Social Value
Most investors throughout the world have a single goal: to earn the highest risk- adjusted financial returns. They would not accept a lower financial return from an investment that also produced social benefits.
More recently, an increasing number of socially-motivated investors have goals beyond maximizing returns. They also seek to align their investments with their social values (value alignment), and some also seek to cause the companies in which they invest to create more social value as a result of their investment (social value creation). We show in this essay that while it is relatively easy to achieve value alignment, creating social value is far more difficult
Differential gene transfers and gene duplications in primary and secondary endosymbioses
BACKGROUND: Most genes introduced into phototrophic eukaryotes during the process of endosymbiosis are either lost or relocated into the host nuclear genome. In contrast, groEL homologues are found in different genome compartments among phototrophic eukaryotes. Comparative sequence analyses of recently available genome data, have allowed us to reconstruct the evolutionary history of these genes and propose a hypothesis that explains the unusual genome distribution of groEL homologues. RESULTS: Our analyses indicate that while two distinct groEL genes were introduced into eukaryotes by a progenitor of plastids, these particular homologues have not been maintained in all evolutionary lineages. This is of significant interest, because two chaperone proteins always co-occur in oxygenic photosynthetic organisms. We infer strikingly different lineage specific processes of evolution involving deletion, duplication and targeting of groEL proteins. CONCLUSION: The requirement of two groEL homologues for chaperon function in phototrophs has provided a constraint that has shaped convergent evolutionary scenarios in divergent evolutionary lineages. GroEL provides a general evolutionary model for studying gene transfers and convergent evolutionary processes among eukaryotic lineages
Herramienta informática para la evaluación de la eficiencia energética en generadores de combustión interna
The use of fossil fuels in electricity generation systems has been used for aspects such as stability and reliability that these machines present. Energy efficiency is defined as the amount of useful energy obtained from a machine, there are various factors that contribute to the efficiency of a machine being lower that stipulated the manufacturer, heat losses are the most representative along with mechanical losses, manufacturers specify in their manuals an efficiency of between 80% and 90% for this type of machines.
The computer tool made it possible to evaluate the energy efficiency in internal combustion generators, a database was consolidated, which was obtained from the classification of information from the historical data generated by the operators of the generator set. Then, in the Matlab software, through the use of neural networks, the input variables involved in the prediction were analyzed, these were thermal energy, load capacity, room temperature, height above sea level where the generator set is located and the losses present in the machine. For the determination of losses present in the machine, method B of the IEEE std112 standard was used, which in its content offers the guide for calculating losses present in the machines and energy efficiency, the result that was obtained with the computer tool and can be taken as a reference for activities such as technical support of the machine, maintenance and efficient operation of the generator set.El empleo de combustibles fósiles en sistemas de generación eléctrica se ha empleado por aspectos como estabilidad y confiabilidad mismos que estas máquinas presentan. La eficiencia energética se define como la cantidad de energÃa útil obtenida de una máquina, existen diversos factores que contribuyen a que la eficiencia de una maquina sea más baja de la estipulada por el fabricante, las pérdidas de calor son las más representativas junto con las pérdidas mecánicas, los fabricantes especifican en sus manuales una eficiencia de entre 80% y 90% para este tipo de máquinas.
La herramienta informática, permitió evaluar la eficiencia energética en generadores de combustión interna, se consolido una base de datos misma que se obtuvo de la clasificación de información de los datos históricos generados por los operarios del grupo electrógeno. Luego, en el software Matlab mediante el empleo de redes neuronales se analizó las variables de entrada que intervienen en la predicción, estas fueron la energÃa térmica, capacidad de carga, temperatura ambiente, altura sobre el nivel del mar en la que se ubica el grupo electrógeno y las pérdidas presentes en la máquina. Para la determinación de pérdidas presentes en la maquina se empleó el método B de la normativa IEEE std112, misma que en su contenido ofrece la guÃa para el cálculo de pérdidas presentes en las máquinas y la eficiencia energética, el resultado que se obtuvo con la herramienta informática puede tomarse como referencia para actividades como soporte técnico de la máquina, mantenimiento y operación eficiente del grupo electrógeno
ASAP: a resource for annotating, curating, comparing, and disseminating genomic data
ASAP is a comprehensive web-based system for community genome annotation and analysis. ASAP is being used for a large-scale effort to augment and curate annotations for genomes of enterobacterial pathogens and for additional genome sequences. New tools, such as the genome alignment program Mauve, have been incorporated into ASAP in order to improve display and analysis of related genomes. Recent improvements to the database and challenges for future development of the system are discussed. ASAP is available on the web at
Proteomic analysis of Plasmodium falciparum histone deacetylase 1 complex proteins
Plasmodium falciparum histone deacetylases (PfHDACs) are an important class of epigenetic regulators that alter protein lysine acetylation, contributing to regulation of gene expression and normal parasite growth and development. PfHDACs are therefore under investigation as drug targets for malaria. Despite this, our understanding of the biological roles of these enzymes is only just beginning to emerge. In higher eukaryotes, HDACs function as part of multi-protein complexes and act on both histone and non-histone substrates. Here, we present a proteomics analysis of PfHDAC1 immunoprecipitates, identifying 26 putative P. falciparum complex proteins in trophozoite-stage asexual intraerythrocytic parasites. The co-migration of two of these (P. falciparum heat shock proteins 70-1 and 90) with PfHDAC1 was validated using Blue Native PAGE combined with Western blot. These data provide a snapshot of possible PfHDAC1 interactions and a starting point for future studies focused on elucidating the broader function of PfHDACs in Plasmodium parasites
Quality of private and public ambulatory health care in low and middle income countries: systematic review of comparative studies
Paul Garner and colleagues conducted a systematic review of 80 studies to compare
the quality of private versus public ambulatory health care in low- and
middle-income countries
Vanillin and Vanillin Analogs Relax Porcine Coronary and Basilar Arteries by Inhibiting L-Type Ca 2+
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