Discriminative learning of Bayesian networks via factorized conditional log-likelihood

We propose an efficient and parameter-free scoring criterion, the factorized conditional log-likelihood (ˆfCLL), for learning Bayesian network classifiers. The proposed score is an approximation of the conditional log-likelihood criterion. The approximation is devised in order to guarantee decomposability over the network structure, as well as efficient estimation of the optimal parameters, achieving the same time and space complexity as the traditional log-likelihood scoring criterion. The resulting criterion has an information-theoretic interpretation based on interaction information, which exhibits its discriminative nature. To evaluate the performance of the proposed criterion, we present an empirical comparison with state-of-the-art classifiers. Results on a large suite of benchmark data sets from the UCI repository show that ˆfCLL-trained classifiers achieve at least as good accuracy as the best compared classifiers, using significantly less computational resources.

Strategic Sales Process Adaptation: Relationship Orientation of the Sales Process in a Business-to-Business Context

Although previous research has recognised adaptation as a central aspect in relationships, the adaptation of the sales process to the buying process has not been studied. Furthermore, the linking of relationship orientation as mindset with adaptation as a strategy and forming the means has not been elaborated upon in previous research. Adaptation in the context of relationships has mostly been studied in relationship marketing. In sales and sales management research, adaptation has been studied with reference to personal selling. This study focuses on adaptation of the sales process to strategically match it to the buyer’s mindset and buying process. The purpose of this study is to develop a framework for strategic adaptation of the seller’s sales process to match the buyer’s buying process in a business-to-business context to make sales processes more relationship oriented. In order to arrive at a holistic view of adaptation of the sales process during relationship initiation, both the seller and buyer are included in an extensive case analysed in the study. However, the selected perspective is primarily that of the seller, and the level focused on is that of the sales process. The epistemological perspective adopted is constructivism. The study is a qualitative one applying a retrospective case study, where the main sources of information are in-depth semi-structured interviews with key informants representing the counterparts at the seller and the buyer in the software development and telecommunications industries. The main theoretical contributions of this research involve targeting a new area in the crossroads of relationship marketing, sales and sales management, and buying and purchasing by studying adaptation in a business-to-business context from a new perspective. Primarily, this study contributes to research in sales and sales management with reference to relationship orientation and strategic sales process adaptation. This research fills three research gaps. Firstly, linking the relationship orientation mindset with adaptation as strategy. Secondly, extending adaptation in sales from adaptation in selling to strategic adaptation of the sales process. Thirdly, extending adaptation to include facilitation of adaptation. The approach applied in the study, systematic combining, is characterised by continuously moving back and forth between theory and empirical data. The framework that emerges, in which linking mindset with strategy with mindset and means forms a central aspect, includes three layers: purchasing portfolio, seller-buyer relationship orientation, and strategic sales process adaptation. Linking the three layers enables an analysis of where sales process adaptation can make a contribution. Furthermore, implications for managerial use are demonstrated, for example how sellers can avoid the ‘trap’ of ad-hoc adaptation. This includes involving the company, embracing the buyer’s purchasing portfolio, understanding the current position that the seller has in this portfolio, and possibly educating the buyer about advantages of adopting a relationship-oriented approach.

Conditional linearization in nonlinear random vibration

In this paper, an improved probabilistic linearization approach is developed to study the response of nonlinear single degree of freedom (SDOF) systems under narrow-band inputs. An integral equation for the probability density function (PDF) of the envelope is derived. This equation is solved using an iterative scheme. The technique is applied to study the hardening type Duffing's oscillator under narrow-band excitation. The results compare favorably with those obtained using numerical simulation. In particular, the bimodal nature of the PDF for the response envelope for certain parameter ranges is brought out.

Assessment of conditional moment closure models of turbulent autoignition using DNS data

A systematic assessment of the submodels of conditional moment closure (CMC) formalism for the autoignition problem is carried out using direct numerical simulation (DNS) data. An initially non-premixed, n-heptane/air system, subjected to a three-dimensional, homogeneous, isotropic, and decaying turbulence, is considered. Two kinetic schemes, (1) a one-step and (2) a reduced four-step reaction mechanism, are considered for chemistry An alternative formulation is developed for closure of the mean chemical source term , based on the condition that the instantaneous fluctuation of excess temperature is small. With this model, it is shown that the CMC equations describe the autoignition process all the way up to near the equilibrium limit. The effect of second-order terms (namely, conditional variance of temperature excess sigma(2) and conditional correlations of species q(ij)) in modeling is examined. Comparison with DNS data shows that sigma(2) has little effect on the predicted conditional mean temperature evolution, if the average conditional scalar dissipation rate is properly modeled. Using DNS data, a correction factor is introduced in the modeling of nonlinear terms to include the effect of species fluctuations. Computations including such a correction factor show that the species conditional correlations q(ij) have little effect on model predictions with a one-step reaction, but those q(ij) involving intermediate species are found to be crucial when four-step reduced kinetics is considered. The "most reactive mixture fraction" is found to vary with time when a four-step kinetics is considered. First-order CMC results are found to be qualitatively wrong if the conditional mean scalar dissipation rate is not modeled properly. The autoignition delay time predicted by the CMC model compares excellently with DNS results and shows a trend similar to experimental data over a range of initial temperatures.

Implementation of conditional phase-shift gate for quantum information processing by NMR, using transition-selective pulses

Experimental realization of quantum information processing in the field of nuclear magnetic resonance (NMR) has been well established. Implementation of conditional phase-shift gate has been a significant step, which has lead to realization of important algorithms such as Grover's search algorithm and quantum Fourier transform. This gate has so far been implemented in NMR by using coupling evolution method. We demonstrate here the implementation of the conditional phase-shift gate using transition selective pulses. As an application of the gate, we demonstrate Grover's search algorithm and quantum Fourier transform by simulations and experiments using transition selective pulses. (C) 2002 Elsevier Science (USA). All rights reserved.

An Adaptive Conditional Zero-Forcing Decoder With Full-Diversity, Least Complexity and Essentially-ML Performance for STBCs

A low complexity, essentially-ML decoding technique for the Golden code and the three antenna Perfect code was introduced by Sirianunpiboon, Howard and Calderbank. Though no theoretical analysis of the decoder was given, the simulations showed that this decoding technique has almost maximum-likelihood (ML) performance. Inspired by this technique, in this paper we introduce two new low complexity decoders for Space-Time Block Codes (STBCs)-the Adaptive Conditional Zero-Forcing (ACZF) decoder and the ACZF decoder with successive interference cancellation (ACZF-SIC), which include as a special case the decoding technique of Sirianunpiboon et al. We show that both ACZF and ACZF-SIC decoders are capable of achieving full-diversity, and we give a set of sufficient conditions for an STBC to give full-diversity with these decoders. We then show that the Golden code, the three and four antenna Perfect codes, the three antenna Threaded Algebraic Space-Time code and the four antenna rate 2 code of Srinath and Rajan are all full-diversity ACZF/ACZF-SIC decodable with complexity strictly less than that of their ML decoders. Simulations show that the proposed decoding method performs identical to ML decoding for all these five codes. These STBCs along with the proposed decoding algorithm have the least decoding complexity and best error performance among all known codes for transmit antennas. We further provide a lower bound on the complexity of full-diversity ACZF/ACZF-SIC decoding. All the five codes listed above achieve this lower bound and hence are optimal in terms of minimizing the ACZF/ACZF-SIC decoding complexity. Both ACZF and ACZF-SIC decoders are amenable to sphere decoding implementation.

Conditional silencing of topoisomerase I gene of Mycobacterium tuberculosis validates its essentiality for cell survival

Topoisomerases are an important class of enzymes for regulating the DNA transaction processes. Mycobacterium tuberculosis (Mtb) is one of the most formidable pathogens also posing serious challenges for therapeutic interventions. The organism contains only one type IA topoisomerase (Rv3646c), offering an opportunity to test its potential as a candidate drug target. To validate the essentiality of M.tuberculosis topoisomerase I (TopoI(Mt)) for bacterial growth and survival, we have generated a conditionally regulated strain of topoI in Mtb. The conditional knockdown mutant exhibited delayed growth on agar plate. In liquid culture, the growth was drastically impaired when TopoI expression was suppressed. Additionally, novobiocin and isoniazid showed enhanced inhibitory potential against the conditional mutant. Analysis of the nucleoid revealed its altered architecture upon TopoI depletion. These studies establish the essentiality of TopoI for the M.tuberculosis growth and open up new avenues for targeting the enzyme.

Induccion del celo en vacas en anestro post parto mediante la administracion de sales minerales, vitaminas y masajes ovaricos. Realizada en el municipio de Rio Blanco, departamento de Matagalpa

El presente estudio se realizó con el objetivo de establecer la efectividad del tratamiento de Inducción al celo de vacas en anestro post parto por medio de la administración de sales minerales, vitaminas y masajes ovarios; dicho tratamiento fue llevado a cabo en el municipio de Río Blanco departamento de Matagalpa. Caracterizándose por una buena distribución de las lluvias la mayor parte del año. El dicho municipio se da una predominancia de una cultura de gran alta productividad ganadera, el tamaño requerido de la muestra de este trabajo de 20 hembras en periodo de anestro post parto mayor de 50 días, las cuales fueron seleccionadas al azar y evalua das clínicamente por palpación rectal por un profesional de la medicina veterinaria. Los datos fueron analizados mediante la prueba de chi –cuadrado habiendo obtenido un resultado significativo a un nivel de confianza del 95% entre los tratamientos. Con base en los resultados obtenidos posterior al tratamiento de la administración de sales minerales, vitamina y masaje ovárico se alcan zó una respuesta positiva del 80 % al celo, el 80% en tasa de preñez y en relación a la aparición del celo posteri or al tratamiento se alcanzo una media de 6.13 días que al comparar la efectividad del tratamiento de solo la aplicación de masaje ovárico se observo un buen resultado positivo, superando las expectativas. En comparación con las hembras tratadas con solo masaje ovárico se obtuvo una respuesta positiva al celo de un 60%, con un 30% de tasa de preñez y 7.33 días promedio en anestro posterior al tratamiento, por lo tanto elaboramos la hipótesis basándonos en el estadígrafo de Chi-cuadrado obteniendo un resultado significativo empleando un nivel de significancia del 0.05% por lo que atribuimos las diferencias de ambos tratamientos.

Estudio preliminar de la utilizacion del agua de mar como suplemento nutritivo de sales minerales, como alternativa para la ganancia de peso en terneros al destete en la Finca "Santa Rita", comarca El Castillo, del municipio de Mulukuku, RAAN

El presente trabajo se realizó con el objetivo de evaluar la utilización del Agua de Mar como suplemento nutritivo de sales minerales, como alternativa en la ganancia de peso en terneros al destete en la Finca Sta. Rita, comarca el Castillo, municipio de Mulukukú, Región Autónoma del Atlántico Norte (RAAN), ubicada en las coordenadas: 13° 10 ́08 ́ ́ N y 085° 05 ́ 18 ́ ́ W, elevación sobre el nivel del mar de 137m. Se empleó un diseño completamente al azar (D.C.A), donde fueron utilizados 30 animales distribuidos aleatoriamente en tres grupos de 10 animales. Tratamiento I: 1 000 ml de agua de mar 1 vez al día por 30 días ; Tratamiento II 1 000 ml de agua de mar 2 veces al día por 30 días; Tratamiento III: Tratamiento testigo (no se aplicó ningún suplemento mineral). Los resultados obtenidos en ganancia de peso vivo, demostraron que no hubo diferencia significativa entre tratamientos, a pesar de esto se observó una pequeña diferencia teniendo los mejores resultados el Tratamiento I seguido del Tratamiento II y por último el Tratamiento III. De igual forma no se obtuvieron diferencias significativas en la ganancia media diaria entre tratamientos, obteniendo el Tratamiento I 0.4089 kg/Animal/dia, para el Tratamiento II fue de 0.3717 kg y para el Tratamiento III fue de 0.3585. Al realizar el análisis financiero observamos que el tratamiento que mayor rentabilidad nos proporcionaría es el Tratamiento I, obteniendo una utilidad neta de $894.96 dólares, el que se emplea en la finca es el Tratamiento III y este nos deja una utilidad neta de $751.02 dólares, al comparar estas utilidades encontramos una diferencia de $143.94 dólares.

Estudio de la conservación in vitro a tasas minimas de crecimiento en piña (Ananas comosus L.) mediante el efecto de osmoreguladores y la dilucion de las sales Murashige y Skoog (1962) a temperaturas de 24ºC y 16 ºC

En el presente estudio se necesitó establecer explantes de piña (Ananas comosus L.) del cultivar Cayena lisa, de los cuales se utilizaron yemas apicales y axilares seleccionadas por su buen estado fisiológico y morfológico. Estas se establecieron en condiciones in vitro utilizando el medio de cultivo básico Murashige & Skoog MS (1962), suplementado con 2 mg/1 de 6-Bencil aminopurina (6-BAP) y 0.02 mg/1 de ácido naftalen acético (ANA) en condiciones controladas de temperatura, humedad relativa e intensidad lumínica. Una vez que se logró micropropagar la cantidad de explantes necesarios para la conservación, se procedió a la aplicación de los inhibidores del crecimiento (manito!y sorbitol) en concentraciones de 10, 20 y 30 g/1 y de la dilución de las sales MS al 25, 50 y 75%, interactuando con temperaturas de 24 oc y 16 oc. A los 120 días de haber permanecido las yemas axilares en las diferentes variantes de medios de cultivo sujetas a estudio, se observó mayor deterioro fisiológico y morfológico de las plántulas en los tratamientos con 1O, 20 y 30 g/1 demanitol y sorbitol. En las variables altura, número de hojas y color de las hojas se experimentaron menores incrementos mensuales, sin embargo se registraron mayores daños, especialmente en las hojas, las cuales presentaron un mayor porcentaje con color verde clorótico a temperaturas de 24ºc de 16 °C. La sobrevivencia fue mayor a temperatura de 16ºc, por el contrario en las diluciones de las sales MS el deterioro fisiológico y morfológico de lasplántulas fue menor, observándose mayor sobrevivencia, presentando mayores porcentajes de coloración verde oscuro y un pequeño porcentaje de plántulas atípicas a temperaturas de 24 °C y 16 °C. También fue notoria la presencia deplántulas atípicas en el manito! y sorbitol a temperatura de 24 °C. Únicamente en el tratamiento a 30 g/1 de sorbitol se observó el fenómeno de vitrificación a temperatura de 24ºc en un 15%. Las diluciones de las sales indujeron mejores resultados en altura, número de hojas y color de las hojas en ambas temperaturas, sus características fenotípicas y genotípicas se mantuvieron iguales a pesar de la reducción del crecimiento