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At least 217 records · Page 12Linked to original sources
PubMed2006

Using an outcomes-logic-model approach to evaluate a faculty development program for medical educators.

PURPOSE: This study used an outcomes-logic-model approach to examine the impact of participating in a nontraditional professional development program. Building and using a logic model provides a structure for the program to examine the degree that the desired learner outcomes, the program delivery methods, and the measurement approaches are aligned. METHOD: Structured telephone interviews were conducted in 2001 with 16 Harvard Medical School (HMS) participants in the Harvard Macy Program for Physician Educators (HM-PE): five who completed the program in 1998, five in 1999, and six in 2000. Interviews were also conducted with four Faculty Scholars, alumni of the HM-PE program who taught in subsequent programs. In 2004, online questionnaires were sent to the 16 participants and four Faculty Scholars. Immediate outcomes, such as greater use of active learning principles, and intermediate outcomes, such as commitment to medical education, were examined. RESULTS: Of those interviewed in 2001, 80% responded to the 2004 online questionnaire. Thirteen of 16 (81%) HMS respondents reported increased knowledge about and confidence using learner-center teaching methods; 10 of 16 (63%) said they gave fewer lectures and added alternative educational methods. Thirteen of 16 (81%) reported a stronger commitment to the field of medical education: almost one third felt the HM-PE program was a turning point in their careers. CONCLUSIONS: The outcomes logic model provided data to judge how well the program mission and plan were implemented, and whether outcomes had been attained.

Boston↗
PubMed1986

Logical description of bovine herpesvirus type 1 latent infection.

Description of the interactions between bovine herpesvirus type 1 (BHV-1) and cattle was performed by the method known as kinetic logic. This logical formalization uses variables with two possible values, 1 and 0, which tell whether an element is present or not at a significant level. To each variable is associated a function which tells if the element is being produced at a significant rate. The temporal relation between a variable and its associated function is given by specific time delays. The BHV-1 infection system is described by a set of five logical equations which tell in what conditions each function is on or off. The five functions are: V, development of viral multiplication; R, development of reactivation of the latent virus; A, development of an immune response; G, establishment of the viral genome; M, development of a memory of a first immune response. Several examples are detailed in a dynamic analysis, in connection with known experimental data.

Animals↗
PubMed2002

High-fidelity quantum logic operations using linear optical elements.

Knill, Laflamme, and Milburn [Nature (London) 409, 46 ((2001))]] have shown that quantum logic operations can be performed using linear optical elements and additional ancilla photons. Their approach is probabilistic in the sense that the logic devices fail to produce an output with a failure rate that scales as 1/n, where n is the number of ancilla. Here we present an alternative approach in which the logic devices always produce an output with an intrinsic error rate that scales as 1/n(2), which may have several advantages in quantum computing applications.

Journal Article↗
PubMed2005

Utilizing logical relationships in genomic data to decipher cellular processes.

The wealth of available genomic data has spawned a corresponding interest in computational methods that can impart biological meaning and context to these experiments. Traditional computational methods have drawn relationships between pairs of proteins or genes based on notions of equality or similarity between their patterns of occurrence or behavior. For example, two genes displaying similar variation in expression, over a number of experiments, may be predicted to be functionally related. We have introduced a natural extension of these approaches, instead identifying logical relationships involving triplets of proteins. Triplets provide for various discrete kinds of logic relationships, leading to detailed inferences about biological associations. For instance, a protein C might be encoded within an organism if, and only if, two other proteins A and B are also both encoded within the organism, thus suggesting that gene C is functionally related to genes A and B. The method has been applied fruitfully to both phylogenetic and microarray expression data, and has been used to associate logical combinations of protein activity with disease state phenotypes, revealing previously unknown ternary relationships among proteins, and illustrating the inherent complexities that arise in biological data.

Algorithms↗
PubMed1999

RNA processing in evolution. The logic of soft-wired genomes.

Direct read-out of information from DNA into RNA allows the genome to be faithfully reproduced in RNA. This outcome occurs in what may be called "hard-wired" organisms. On the other hand, in what we refer to as "soft-wired" organisms, RNA is processed extensively, allowing a number of different messages to be produced from the same gene. As a consequence, the nucleotide sequences present in RNA (referred to here as the ribotype) differ from those present in DNA (the genotype). In soft-wired organisms, RNA processing can be thought of as a series of steps, one or more of which have two mutually exclusive outcomes: a "default" outcome and an "alternative" outcome. In the presence of appropriate regulatory signals, the RNA is processed using the alternative pathway, while the default pathway is used in their absence. The setup is functionally equivalent to that found in binary "logic gates." In both cases, "logical operations" are implemented by using regulatory signals to establish a conditional relationship between input and output and can be described using the Boolean operators AND, OR, and NOT. In the case of RNA processing events, the outcomes can be used either to directly regulate cellular responses or to control other RNA processing events. In the latter case, "networks" are established that make processing of one RNA contingent on another. Such networks allow cells to respond to their surroundings by changing the connectivity between different RNA processing events, using RNA as a substrate to compute an appropriate response. As such logical operations impact phenotype, they are subject to natural selection. Through reverse transcription, successful outcomes can be incorporated into the genome.

Animals↗
PubMed2001

Logic circuits with carbon nanotube transistors.

We demonstrate logic circuits with field-effect transistors based on single carbon nanotubes. Our device layout features local gates that provide excellent capacitive coupling between the gate and nanotube, enabling strong electrostatic doping of the nanotube from p-doping to n-doping and the study of the nonconventional long-range screening of charge along the one-dimensional nanotubes. The transistors show favorable device characteristics such as high gain (>10), a large on-off ratio (>10(5)), and room-temperature operation. Importantly, the local-gate layout allows for integration of multiple devices on a single chip. Indeed, we demonstrate one-, two-, and three-transistor circuits that exhibit a range of digital logic operations, such as an inverter, a logic NOR, a static random-access memory cell, and an ac ring oscillator.

Journal Article↗
PubMed2005

Spectroscopy using quantum logic.

We present a general technique for precision spectroscopy of atoms that lack suitable transitions for efficient laser cooling, internal state preparation, and detection. In our implementation with trapped atomic ions, an auxiliary "logic" ion provides sympathetic laser cooling, state initialization, and detection for a simultaneously trapped "spectroscopy" ion. Detection is achieved by applying a mapping operation to each ion, which results in a coherent transfer of the spectroscopy ion's internal state onto the logic ion, where it is then measured with high efficiency. Experimental realization, by using 9Be+ as the logic ion and 27Al+ as the spectroscopy ion, indicates the feasibility of applying this technique to make accurate optical clocks based on single ions.

Journal Article↗
PubMed2006

Majority logic gate for magnetic quantum-dot cellular automata.

We describe the operation of, and demonstrate logic functionality in, networks of physically coupled, nanometer-scale magnets designed for digital computation in magnetic quantum-dot cellular automata (MQCA) systems. MQCA offer low power dissipation and high integration density of functional elements and operate at room temperature. The basic MQCA logic gate, that is, the three-input majority logic gate, is demonstrated.

Journal Article↗
PubMed1999

Electronically configurable molecular-based logic gates

Logic gates were fabricated from an array of configurable switches, each consisting of a monolayer of redox-active rotaxanes sandwiched between metal electrodes. The switches were read by monitoring current flow at reducing voltages. In the "closed" state, current flow was dominated by resonant tunneling through the electronic states of the molecules. The switches were irreversibly opened by applying an oxidizing voltage across the device. Several devices were configured together to produce AND and OR logic gates. The high and low current levels of those gates were separated by factors of 15 and 30, respectively, which is a significant enhancement over that expected for wired-logic gates.

Journal Article↗
PubMed1994

Relationship between a fuzzy logic and a steepest descent approach to optimize a feedforward artificial neural network configuration.

The neural network designer must take into consideration many factors when selecting an appropriate network configuration. The performance of a given network configuration is influenced by many different factors such as: accuracy, training time, sensitivity, and the number of neurons used in the implementation. Using a cost function based on the four criteria mentioned previously, the various network paradigms can be evaluated relative to one another. If the mathematical models of the evaluation criteria as functions of the network configuration are known, then traditional techniques (such as the steepest descent method) could be used to determine the optimal network configuration. The difficulty in selecting an appropriate network configuration is due to the difficulty involved in determining the mathematical models of the evaluation criteria. This difficulty can be avoided by using fuzzy logic techniques to perform the network optimization as opposed to the traditional techniques. Fuzzy logic avoids the need of a detailed mathematical description of the relationship between the network performance and the network configuration, by using heuristic reasoning and linguistic variables. A comparison will be made between the fuzzy logic approach and the steepest descent method for the optimization of the cost function. The fuzzy optimization procedure could be applied to other systems where there is a priori information about their characteristics.

Electronic Data Processing↗
PubMed1995

Tackling evaluation: applying a programme logic model to community rehabilitation for adults with brain injury.

Programme evaluation has become an important component of many rehabilitation initiatives in both institutional and community environments. Of key importance is a need for information on developing an evaluation framework to determine and address programme processes and outcomes. This paper presents a programme logic model used to guide the evaluation of a community rehabilitation programme for adults with brain injury. Programme logic models are visual models that provide a framework to organize and integrate information about programme inputs, processes and outcomes. The model is also used in this programme to incorporate the client-centred values of the programme. It was developed through the consensus of the entire team, and was used to plan implementation and outcome evaluations. A similar programme logic model will be useful to occupational therapists and other health care professionals planning programme evaluations of their services.

Adult↗
PubMed2003

Evaluating the California Wellness Foundation's Health Improvement Initiative: a logic model approach.

The difficulties of conducting randomized trials to evaluate community-based initiatives have led some researchers to argue in favor of a case study "logic model" approach to evaluation. This article describes a case study logic approach adopted for the evaluation of one community initiative, the Health Improvement Initiative (HII) funded by the California Wellness Foundation (TCWF). The HII is a comprehensive, community-based initiative designed to improve population health by implementing and sustaining community-level systems changes. Nine communities received funding to create broad-based community coalitions (Health Partnerships) that were charged with developing and implementing action plans around systems change. The HII is being evaluated using a case-study logic-model approach that uses quantitative and qualitative data to construct indicators of coalition functioning, systems changes, and population health. By examining the relationship between these indicators over time, it should be possible to determine if any changes in intermediate or long-term outcomes are associated with Health Partnership activities.

California↗
PubMed2001

Cis-regulatory logic in the endo16 gene: switching from a specification to a differentiation mode of control.

The endo16 gene of Strongylocentrotus purpuratus encodes a secreted protein of the embryonic and larval midgut. The overall functional organization of the spatial and temporal control system of this gene are relatively well known from a series of earlier cis-regulatory studies. Our recent computational model for the logic operations of the proximal region of the endo16 control system (Module A) specifies the function of interactions at each transcription factor target site of Module A. Here, we extend sequence level functional analysis to the adjacent cis-regulatory region, Module B. The computational logic model is broadened to include B/A interactions as well as other Module B functions. Module B drives expression later in development and its major activator is responsible for a sharp, gut-specific increase in transcription after gastrulation. As shown earlier, Module B output undergoes a synergistic amplification that requires interactions within Module A. The interactions within Module B that are required to generate and transmit its output to Module A are identified. Logic considerations predicted an internal cis-regulatory switch by which spatial control of endo16 expression is shifted from Module A (early) to Module B (later). This prediction was confirmed experimentally and a distinct set of interactions in Module B that mediate the switch function was demonstrated. The endo16 computational model now provides a detailed explanation of the information processing functions executed by the cis-regulatory system of this gene throughout embryogenesis. Early in development the gene participates in the specification events that define the endomesoderm; later it functions as a gut-specific differentiation gene. The cis-regulatory switch mediates this functional change.

Animals↗
PubMed2004

Terabit all-optical logic based on ultrafast two-dimensional transmission gating.

Terabit all-optical complementary logic is proposed using two successive time slots to represent a unique logical status. An organic molecular thin film is used as an array of optically controlled optical switches. By utilizing the planar structure of the film and its ultrafast optical response, proof-of-principle fully optical NOT and AND logic operations were demonstrated with 400-fs interval pulses.

Journal Article↗
PubMed2005

Injection-locking laser-diode-based OC-192 optical non-return-to-zero-to-return-to-zero OR logic gate.

An OC-192 optical return-to-zero- (RZ-) formatted OR logic gate is experimentally demonstrated and theoretically interpreted for the first time to our knowledge. It is implemented by using a data format converter based on an optically injection-locked Fabry-Perot laser diode (FPLD) modulated in below-threshold condition. By injecting two non-return-to-zero data streams into the FPLD-based OR gate, a peak-power-equalized RZ-formatted OR logic data stream extinction ratio of >8 dB is obtained from the FPLD with optimized rf-modulating and optical injecting powers of 24.7 and >-4 dBm, respectively. The highest data rate of up to 12.5 Gbits/s with a bit error rate (BER) of 10(-13) at a received optical power of >-16 dBm can be achieved by increasing the dc bias current of the FPLD-based RZ-formatted OR logic gate to 8 mA. The OR-gated RZ data stream exhibits a duty cycle (pulse width) of approximately 27% (27 ps) and a 0.5 dB power penalty at a BER of 10(-9) at a data rate of 9.953 Gbits/s.

Journal Article↗
PubMedDate not supplied

Value innovation: the strategic logic of high growth.

Why are some companies able to sustain high growth in revenues and profits--and others are not? To answer that question, the authors, both of INSEAD, spent five years studying more than 30 companies around the world. They found that the difference between the high-growth companies and their less successful competitors was in each group's assumptions about strategy. Managers of the less successful companies followed conventional strategic logic. Managers of the high-growth companies followed what the authors call the logic of value innovation. Conventional strategic logic and value innovation differ along the basic dimensions of strategy. Many companies take their industry's conditions as given; value innovators don't. Many companies let competitors set the parameters of their strategic thinking; value innovators do not use rivals as benchmarks. Rather than focus on the differences among customers, value innovators look for what customers value in common. Rather than view opportunities through the lens of existing assets and capabilities, value innovators ask, What if we start anew? The authors tell the story of the French hotelier Accor, which discarded the notion of what a hotel is supposed to look like in order to offer what most customers want: a good night's sleep at a low price. And Virgin Atlantic challenged industry conventions by eliminating first-class service and channeling savings into innovations for business-class passengers. Those companies didn't set out to build advantages over the competition, but they ended up achieving the greatest competitive advantages.

Administrative Personnel↗
PubMedDate not supplied

[Use of three-valued logic to enhance the stability of interpretation algorithms in medical diagnostic devices].

The procedure proposed for converting the binary production principles to the three-valued form, the relationship found between the well-known three-valued logic networks, and the particular properties of three-valued logic expressions permit introduction of the mechanisms that are responsible for three-valued production principles and the construction of logic conclusions by the results of this variation. The apparatus designed ensures a higher stability of ECG interpretation without lowering its efficiency and makes it possible to estimate the quality of interpretation by the capacities of the apparatus itself.

Algorithms↗
PubMed2003

Logical ontology for mediating between nursing intervention terminology systems.

OBJECTIVES: Several researchers have proposed the use of logical ontologies as 'reference terminologies'. However, there are a number of unresolved issues. This article describes the development of a logical ontology for nursing interventions and presents the results of evaluation. METHODS: Initially this study involved the development in GRAIL of two separate experimental ontologies: an ontology based on the textual content of informal definitions for nursing interventions drawn from the Nursing Interventions Classification; and an ontology based on labels for the same nursing interventions. Following initial bench-testing, the ontology based on labels was selected for extension (to accommodate also nursing intervention components of the Home Health Care Classification System and the Omaha System), for further testing and for external evaluation. RESULTS: A hierarchy of nursing interventions generated automatically from the experimental ontology based on informal definitions contained only 3 hierarchical relationships, compared to 214 for the initial ontology based on labels. For the final extended ontology based on labels, the generated hierarchy contained the three source terminology systems in entirety - there were a total of 2861 hierarchical relationships. While the results of comparative bench testing of the final ontology were favourable, the results of external evaluation were mixed and showed little agreement between reviewers. CONCLUSION: This study suggests that while a logical ontology based on labels might be a useful tool for mediating between nursing intervention terminology systems, a formative consensus type development methodology might improve the approach by helping to harmonise ideological differences that may exist across the nursing profession.

Humans↗