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La globalización implica para los países de la región grandes oportunidades y desafíos. La idea de que el planeta es una “aldea global” es una visión que está en vigencia en este siglo. La globalización ha traído consigo efectos positivos como la socialización a nivel mundial de ideas sobre el respeto a los derechos humanos y el valor que tiene la democracia en el desarrollo de los países. El proceso de globalización está integrando económicamente a los países, por este motivo en los últimos años han surgido productores de bienes y servicio a escala mundial, que ofrecen sus productos cada vez más integrados y más homogéneos. Por lo tanto esta tesis se enfoca en analizar los problemas del área de producción de Procarsa que evitan que esta empresa sea competitiva en el mercado. A lo largo de la tesis se analizará que los principales problemas de esta empresa, la cual deducira que no ha renovado su maquinaria hace más de 30 años, y cuenta con equipos de hasta 47 años de antigüedad. A pesar de tener un eficiente mantenimiento se presentan inconvenientes en planta, y requiere que llegue la hora del recambio, para estar a la altura de la globalización y ser competitivo en el mercado. Se analizara mediante la herramienta del cuestionario donde está el problema crítico de la empresa. Por lo tanto se presentara como solución la innovación tecnológica, quedando como punto pendiente la aplicación de esta solución que puede ser suficientemente sustentado con herramientas de ingeniería económica. Se espera que implementada la solución la empresa sea líder en la región.

Las enfermedades transmitidas por alimentos constituyen, a nivel mundial, uno de los problemas más generalizados y de mayor repercusión sobre la salud de personas, afectando generalmente a la población de bajos recursos, niños, mujeres embarazadas y ancianos. La presente revisión no pretende sentar cátedra sobre el análisis de las enfermedades producidas por alimentos, más bien está pensado como una etapa más de un proceso necesario y permanente, en la promoción y prevención de dicha patología.

Purpose Using a proposed model, the purpose of this paper is to categorize small and medium enterprises’ (SMEs) owners/managers’ perceptions of customer service, and of the manifestations and observable behaviors in relation to the most frequent repercussions of domestic violence in the workplace. Design/methodology/approach A sample of 73 SME owners/managers was selected; a survey with 44 variables was used for data collection; and factorial and canonical analysis techniques were used to analyze the data. Findings The following were found: among the most frequent manifestations of domestic violence in SME customer services, there are four categories that explain 69.46 percent of the model of variance: threats and continuous absences, frequent mistakes and bad relationships, physical damage/lack of concentration and negative manifestation with low self-esteem; among observable behavior at the workplace, there are four categories that explain 65.35 percent of the model of variance: lack of concentration/tearfulness, fear/insecurity, limited attention to customers and continuous threats; finally there is a 96.70 percent probability of the SMEs’ productivity being affected (loss of customers and low production), through three manifestations of domestic violence detected in the employees: tiredness, sleepiness and tearfulness. Research limitations/implications This research is circumscribed to only one geographical zone in Puerto Rico. Practical implications Even only three manifestations of domestic violence in workers will significantly decrease productivity. When SME managers detect these, they can take action to mitigate the problem for the benefit of the workers. Originality/value This study is a pioneer proposal in its analytical quantitative approach on domestic violence in Puerto Rico and its repercussions on the productivity of the service sector, using canonical analysis.

Pattern separation is a fundamental brain computation that converts small differences in synaptic input patterns into large differences in action potential (AP) output patterns. Pattern separation plays a key role in the dentate gyrus, enabling the efficient storage and recall of memories in downstream hippocampal CA3 networks. Several mechanisms for pattern separation have been proposed, including expansion of coding space, sparsification of neuronal activity, and simple thresholding mechanisms. Alternatively, a winner-takes-all mechanism, in which the most excited cells inhibit all less-excited cells by lateral inhibition, might be involved. Although such a mechanism is computationally powerful, it remains unclear whether it operates in biological networks. Here, we develop a full-scale network model of the dentate gyrus, comprised of granule cells (GCs) and parvalbumin+ (PV+) inhibitory interneurons, based on experimentally determined biophysical cellular properties and synaptic connectivity rules. Our results demonstrate that a biologically realistic principal neuron–interneuron (PN–IN) network model is a highly efficient pattern separator. Mechanistic dissection in the model revealed that a winner-takes-all mechanism by lateral inhibition plays a crucial role in pattern separation. Furthermore, both fast signaling properties of PV+ interneurons and focal GC–interneuron connectivity are essential for efficient pattern separation. Thus, PV+ interneurons are not only involved in basic microcircuit functions, but also contribute to higher-order computations in neuronal networks, such as pattern separation.

Recently, great attention has been given to microbial fuel cells (CCM) due to their moderate operating conditions and the use of a variety of biodegradable substrates as fuel. The common microbial fuel cells consist of an anodic chamber and a cathode chamber separated by a proton exchange membrane. The microorganisms actively catabolize the substrate generating bioelectricity. These cells can be used as an energy generator for biosensors, giving this a great advantage for application in these types of devices. This paper presents microbial fuel lines, designed at low cost, in which the concentration of sludge has been varied, which was obtained from the oxidation lagoons of Covicorti, Trujillo-La Libertad. The values ​​of the average voltage were reduced as the concentration of the mud decreases, from values ​​close to 507.8 to 244.1 mV. The conductivity in the anodic chamber was around 14.5 to 7.75 μS / cm with a pH around 8.0. While in the cathodic carame a pH around 7.5 and a turbidity between 250 to 450 NTU was found, the values ​​of current intensity and power density also decrease with the reduction of residual sludge. With this work, it is about giving a new way of manufacturing CCM in an innovative and economical way. Recientemente, se ha puesto gran atención a las celdas de combustible microbianas (CCM) debido a sus condiciones de operación moderadas y al uso de una variedad de sustratos biodegradables como combustible. Las celdas de combustible microbianas comunes consisten en una cámara anódica y una cámara catódica separadas por una membrana de intercambio protónico. Los microorganismos catabolizan activamente el sustrato generando bioelectricidad. Estas celdas se pueden utilizar como un generador de energía para biosensores, dando con esto una gran ventaja para aplicación en estos tipos de dispositivos. En este trabajo se presenta cedas de combustible microbianas, diseñadas a bajo costo, en las cuales se ha variado la concentración de lodo, el cual fue obtenido de las lagunas de oxidación de Covicorti, Trujillo- La Libertad. Los valores del voltaje promedio fueron reduciendo a medida que disminuye la concentración del lodo, desde valores cercanos a 507.8 a 244.1 mV. La conductividad en la cámara anódica estuvo alrededor de 14,5 a 7,75 µS/cm con un pH alrededor de 8,0. Mientras que en la carama catódica se encontró un pH alrededor de 7,5 y una turbidez entre 250 a 450 UNT; los valores de la intensidad de corriente y densidad de potencia también disminuyen con la disminución de lodo residual. Con este trabajó se trata de dar una nueva forma de fabricación de CCM de manera innovadora y económica.

The hippocampal CA3 region plays a key role in learning and memory. Recurrent CA3–CA3 synapses are thought to be the subcellular substrate of pattern completion. However, the synaptic mechanisms of this network computation remain enigmatic. To investigate these mechanisms, we combined functional connectivity analysis with network modeling. Simultaneous recording from up to eight CA3 pyramidal neurons revealed that connectivity was sparse, spatially uniform, and highly enriched in disynaptic motifs (reciprocal, convergence, divergence, and chain motifs). Unitary connections were composed of one or two synaptic contacts, suggesting efficient use of postsynaptic space. Real-size modeling indicated that CA3 networks with sparse connectivity, disynaptic motifs, and single-contact connections robustly generated pattern completion. Thus, macro- and microconnectivity contribute to efficient memory storage and retrieval in hippocampal networks.

La desnutrición es un fenómeno complejo y multidimensional. Depende de factores como la disponibilidad de alimentos, de agua, el acceso económico, a servicios de salud, el saneamiento ambiental, entre otros. En la provincia de Manabí, Ecuador, fue posible identificar indicadores con los cuales se pueden medir las distintas dimensiones de la seguridad alimentaria, como factores determinantes de la desnutrición crónica infantil a escala cantonal. En este artículo se determinaron las causas del problema de la desnutrición crónica infantil en la provincia de Manabí a escala cantonal teniendo en cuenta cuánta población la padece y la capacidad de respuesta que tiene cada cantón para resolver el problema. El método de medida permitió establecer prioridades tanto geográficas como sectoriales para la distribución de recursos.

CA3–CA3 recurrent excitatory synapses are thought to play a key role in memory storage and pattern completion. Whether the plasticity properties of these synapses are consistent with their proposed network functions remains unclear. Here, we examine the properties of spike timing-dependent plasticity (STDP) at CA3–CA3 synapses. Low-frequency pairing of excitatory postsynaptic potentials (EPSPs) and action potentials (APs) induces long-term potentiation (LTP), independent of temporal order. The STDP curve is symmetric and broad (half-width ~150 ms). Consistent with these STDP induction properties, AP–EPSP sequences lead to supralinear summation of spine [Ca2+] transients. Furthermore, afterdepolarizations (ADPs) following APs efficiently propagate into dendrites of CA3 pyramidal neurons, and EPSPs summate with dendritic ADPs. In autoassociative network models, storage and recall are more robust with symmetric than with asymmetric STDP rules. Thus, a specialized STDP induction rule allows reliable storage and recall of information in the hippocampal CA3 network.

Parvalbumin-positive (PV+) GABAergic interneurons in hippocampal microcircuits are thought to play a key role in several higher network functions, such as feedforward and feedback inhibition, network oscillations, and pattern separation. Fast lateral inhibition mediated by GABAergic interneurons may implement a winner-takes-all mechanism in the hippocampal input layer. However, it is not clear whether the functional connectivity rules of granule cells (GCs) and interneurons in the dentate gyrus are consistent with such a mechanism. Using simultaneous patch-clamp recordings from up to seven GCs and up to four PV+ interneurons in the dentate gyrus, we find that connectivity is structured in space, synapse-specific, and enriched in specific disynaptic motifs. In contrast to the neocortex, lateral inhibition in the dentate gyrus (in which a GC inhibits neighboring GCs via a PV+ interneuron) is ~ 10-times more abundant than recurrent inhibition (in which a GC inhibits itself). Thus, unique connectivity rules may enable the dentate gyrus to perform specific higher-order computations., GABAergic interneurons are known to provide inhibition to allow computational function of neuronal network. Here, Espinoza and colleagues show that connectivity of granule cells and interneurons in the dentate gyrus of mouse hippocampus are consistent with the circuit architecture capable of performing a winners-take-all mechanism.

ATP released from neurons and astrocytes during neuronal activity or under pathophysiological circumstances is able to influence information flow in neuronal circuits by activation of ionotropic P2X and metabotropic P2Y receptors and subsequent modulation of cellular excitability, synaptic strength, and plasticity. In the present paper we review cellular and network effects of P2Y receptors in the brain. We show that P2Y receptors inhibit the release of neurotransmitters, modulate voltage- and ligand-gated ion channels, and differentially influence the induction of synaptic plasticity in the prefrontal cortex, hippocampus, and cerebellum. The findings discussed here may explain how P2Y1 receptor activation during brain injury, hypoxia, inflammation, schizophrenia, or Alzheimer’s disease leads to an impairment of cognitive processes. Hence, it is suggested that the blockade of P2Y1 receptors may have therapeutic potential against cognitive disturbances in these states.

ATP released from neurons and astrocytes during neuronal activity or under pathophysiological circumstances is able to influence information flow in neuronal circuits by activation of ionotropic P2X and metabotropic P2Y receptors and subsequent modulation of cellular excitability, synaptic strength, and plasticity. In the present paper we review cellular and network effects of P2Y receptors in the brain. We show that P2Y receptors inhibit the release of neurotransmitters, modulate voltage- and ligand-gated ion channels, and differentially influence the induction of synaptic plasticity in the prefrontal cortex, hippocampus, and cerebellum. The findings discussed here may explain how P2Y1receptor activation during brain injury, hypoxia, inflammation, schizophrenia, or Alzheimer’s disease leads to an impairment of cognitive processes. Hence, it is suggested that the blockade of P2Y1receptors may have therapeutic potential against cognitive disturbances in these states.

Current responses to N-methyl-D-aspartate (NMDA) in layer V pyramidal neurons of the rat prefrontal cortex were potentiated by the P2 receptor agonists adenosine 5'-triphosphate (ATP) and uridine 5'-triphosphate (UTP). The failure of these nucleotides to induce inward current on fast local superfusion suggested the activation of P2Y rather than P2X receptors. The potentiation by ATP persisted in a Ca(2+)-free superfusion medium but was abolished by 1,2-bis(2-amino-5-fluorophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis(acetoxymethyl) ester, cyclopiazonic acid, 7-nitroindazole, fluoroacetic acid, bafilomycin, and tetanus toxin, indicating that an astrocytic signaling molecule may participate. Because the metabotropic glutamate receptor (mGluR) agonists (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (ACPD) (group I/II) and (RS)-3,5-dihydroxyphenylglycine (group I) both imitated the effect of ATP and the group I mGluR antagonist 1-aminoindan-1,5-dicarboxylic acid or a combination of selective mGluR(1) (7-(hydroxyimino)-cyclopropa[b]chromen-1a-carboxylate) and mGluR(5) (2-methyl-6-(phenylethynyl)pyridine) antagonists abolished the facilitation by ATP, it was concluded that the signaling molecule may be glutamate. Pharmacological tools known to interfere with the transduction cascade of type I mGluRs (guanosine 5'-O-(3-thiodiphosphate), U-73122, xestospongin C, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, calmodulin kinase II [CAMKII] inhibitor peptide) depressed the actions of both ATP and ACPD. Characterization of the P2Y receptor by agonists (ATP and UTP), antagonists (suramin and pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid), and knockout mice (P2Y(2)(-/-)) suggested that the nucleotides act at the P2Y(4) subtype. In conclusion, we propose that exogenous and probably also endogenous ATP release vesicular glutamate from astrocytes by P2Y(4) receptor activation. This glutamate then stimulates type I mGluRs of layer V pyramidal neurons and via the G(q)/phospholipase C/inositol 1,4,5-trisphosphate/Ca(2+)/CAMKII transduction pathway facilitates NMDA receptor currents.

Intracellular electrophysiological recordings provide crucial insights into elementary neuronal signals such as action potentials and synaptic currents. Analyzing and interpreting these signals is essential for a quantitative understanding of neuronal information processing, and requires both fast data visualization and ready access to complex analysis routines. To achieve this goal, we have developed Stimfit, a free software package for cellular neurophysiology with a Python scripting interface and a built-in Python shell. The program supports most standard file formats for cellular neurophysiology and other biomedical signals through the Biosig library. To quantify and interpret the activity of single neurons and communication between neurons, the program includes algorithms to characterize the kinetics of presynaptic action potentials and postsynaptic currents, estimate latencies between pre- and postsynaptic events, and detect spontaneously occurring events. We validate and benchmark these algorithms, give estimation errors, and provide sample use cases, showing that Stimfit represents an efficient, accessible and extensible way to accurately analyze and interpret neuronal signals.

Intracellular electrophysiological recordings provide crucial insights into elementary neuronal signals such as action potentials and synaptic currents. Analyzing and interpreting these signals is essential for a quantitative understanding of neuronal information processing, and requires both fast data visualization and ready access to complex analysis routines. To achieve this goal, we have developed Stimfit, a free software package for cellular neurophysiology with a Python scripting interface and a built-in Python shell. The program supports most standard file formats for cellular neurophysiology and other biomedical signals through the Biosig library. To quantify and interpret the activity of single neurons and communication between neurons, the program includes algorithms to characterize the kinetics of presynaptic action potentials and postsynaptic currents, estimate latencies between pre- and postsynaptic events, and detect spontaneously occurring events. We validate and benchmark these algorithms, give estimation errors, and provide sample use cases, showing that Stimfit represents an efficient, accessible and extensible way to accurately analyze and interpret neuronal signals.

Magnetite (Fe3O4) and hematite (α-Fe2O3) iron oxide nanoparticles were synthesized using the co-precipitation method via subsequent heat treatment using ferrous chloride (FeCl2.4H2O) as a source of iron. The synthesized powder was annealed at high temperature in an air atmosphere to promote the formation of the hematite (α-Fe2O3) phase. Both oxide phases of iron oxide were characterized using x-ray diffraction, thermogravimetric, and differential scanning calorimetric analysis, and Raman spectroscopy. The phases of as-synthesized nanoparticles were confirmed by XRD and Raman studies. The thermal behavior and weight loss of the initial powdered Fe3O4 to α-Fe2O3 was studied using TG-DSC analysis. In the present case, the Fe3O4 and α-Fe2O3 nanoparticles were used for the electrochemical sensing of acetaminophen (C6H9NO2). The sensing of acetaminophen was performed by Fe3O4 and α-Fe2O3 modified glassy carbon electrode, using a potential controlled cyclic voltammetric technique. The Fe3O4 and α-Fe2O3 nanoparticles exhibited electrocatalytic ability for sensing acetaminophen. Detailed results are included.

CA3 pyramidal neurons are important for memory formation and pattern completion in the hippocampal network. It is generally thought that proximal synapses from the mossy fibers activate these neurons most efficiently, whereas distal inputs from the perforant path have a weaker modulatory influence. We used confocally targeted patch-clamp recording from dendrites and axons to map the activation of rat CA3 pyramidal neurons at the subcellular level. Our results reveal two distinct dendritic domains. In the proximal domain, action potentials initiated in the axon backpropagate actively with large amplitude and fast time course. In the distal domain, Na(+) channel-mediated dendritic spikes are efficiently initiated by waveforms mimicking synaptic events. CA3 pyramidal neuron dendrites showed a high Na(+)-to-K(+) conductance density ratio, providing ideal conditions for active backpropagation and dendritic spike initiation. Dendritic spikes may enhance the computational power of CA3 pyramidal neurons in the hippocampal network.