Reasoning about discontinuance of information system use

While many studies have explored conditions and consequences of information systems adoption and use, few have focused on the final stages of the information system lifecycle. In this paper, I develop a theoretical and an initial empirical contribution to understanding individuals’ intentions to discontinue the use of an information system. This understanding is important because it yields implications about maintenance, retirement, and users’ switching decisions, which ultimately can affect work performance, system effectiveness, and return on technology investments. In this paper, I offer a new conceptualization of factors determining users’ intentions to discontinue the use of information systems. I then report on a preliminary empirical test of the model using data from a field study of information system users in a promotional planning routine in a large retail organization. Results from the empirical analysis provide first empirical support for the theoretical model. I discuss the work’s implications for theory on information systems continuance and dual-factor logic in information system use. I also provide suggestions for managers dealing with cessation of information systems and broader work routine change in organizations due to information system end-of-life decisions.

Using a botanic garden collection to test a bioclimatic vegetation scheme

Vegetation maps and bioclimatic zone classifications communicate the vegetation of an area and are used to explain how the environment regulates the occurrence of plants on large scales. Many practises and methods for dividing the world’s vegetation into smaller entities have been presented. Climatic parameters, floristic characteristics, or edaphic features have been relied upon as decisive factors, and plant species have been used as indicators for vegetation types or zones. Systems depicting vegetation patterns that mainly reflect climatic variation are termed ‘bioclimatic’ vegetation maps. Based on these it has been judged logical to deduce that plants moved between corresponding bioclimatic areas should thrive in the target location, whereas plants moved from a different zone should languish. This principle is routinely applied in forestry and horticulture but actual tests of the validity of bioclimatic maps in this sense seem scanty. In this study I tested the Finnish bioclimatic vegetation zone system (BZS). Relying on the plant collection of Helsinki University Botanic Garden’s Kumpula collection, which according to the BZS is situated at the northern limit of the hemiboreal zone, I aimed to test how the plants’ survival depends on their provenance. My expectation was that plants from the hemiboreal or southern boreal zones should do best in Kumpula, whereas plants from more southern and more northern zones should show progressively lower survival probabilities. I estimated probability of survival using collection database information of plant accessions of known wild origin grown in Kumpula since the mid 1990s, and logistic regression models. The total number of accessions I included in the analyses was 494. Because of problems with some accessions I chose to separately analyse a subset of the complete data, which included 379 accessions. I also analysed different growth forms separately in order to identify differences in probability of survival due to different life strategies. In most analyses accessions of temperate and hemiarctic origin showed lower survival probability than those originating from any of the boreal subzones, which among them exhibited rather evenly high probabilities. Exceptionally mild and wet winters during the study period may have killed off hemiarctic plants. Some winters may have been too harsh for temperate accessions. Trees behaved differently: they showed an almost steadily increasing survival probability from temperate to northern boreal origins. Various factors that could not be controlled for may have affected the results, some of which were difficult to interpret. This was the case in particular with herbs, for which the reliability of the analysis suffered because of difficulties in managing their curatorial data. In all, the results gave some support to the BZS, and especially its hierarchical zonation. However, I question the validity of the formulation of the hypothesis I tested since it may not be entirely justified by the BZS, which was designed for intercontinental comparison of vegetation zones, but not specifically for transcontinental provenance trials. I conclude that botanic gardens should pay due attention to information management and curational practices to ensure the widest possible applicability of their plant collections.

Information Technology Development Needs in Community Pharmacies : A Strategic Approach

In the context of health care, information technology (IT) has an important role in the operational infrastructure, ranging from business management to patient care. An essential part of the system is medication management in inpatient and outpatient care. Community pharmacists strategy has been to extend practice responsibilities beyond dispensing towards patient care services. Few studies have evaluated the strategic development of IT systems to support this vision. The objectives of this study were to assess and compare independent Finnish community pharmacy owners and staff pharmacists priorities concerning the content and structure of the next generation of community pharmacy IT systems, to explore international experts visions and strategic views on IT development needs in relation to services provided in community pharmacies, to identify IT innovations facilitating patient care services and to evaluate their development and implementation processes, and to assess community pharmacists readiness to adopt innovations. This study applied both qualitative and quantitative methods. A qualitative personal interview of 14 experts in community pharmacy services and related IT from eight countries and a national survey of Finnish community pharmacy owners (mail survey, response rate 53%, n=308), and of a representative sample of staff pharmacists (online survey, response rate 22%, n=373) were conducted. Finnish independent community pharmacy owners gave priority to logistical functions but also to those related to medication information and patient care. The managers and staff pharmacists have different views of the importance of IT features, reflecting their different professional duties in the community pharmacy. This indicates the need for involving different occupation groups in planning the new IT systems for community pharmacies. A majority of the international experts shared the vision of community pharmacy adopting a patient care orientation; supported by IT-based documentation, new technological solutions, access to information, and shared patient data. Community pharmacy IT innovations were rare, which is paradoxical because owners and staff pharmacists perception of their innovativeness was seen as being high. Community pharmacy IT systems development processes usually had not undergone systematic needs assessment research beforehand or evaluation after the implementation and were most often coordinated by national governments without subsequent commercialization. Specifically, community pharmacy IT developments lack research, organization, leadership and user involvement in the process. Those responsible for IT development in the community pharmacy sector should create long-term IT development strategies that are in line with community pharmacy service development strategies. This could provide systematic guidance for future projects to ensure that potential innovations are based on a sufficient understanding of pharmacy practice problems that they are intended to solve, and to encourage strong leadership in research, development of innovations so that community pharmacists potential innovativeness is used, and that professional needs and strategic priorities will be considered even if the development process is led by those outside the profession.

Compression of Weighted Graphs

We propose to compress weighted graphs (networks), motivated by the observation that large networks of social, biological, or other relations can be complex to handle and visualize. In the process also known as graph simplication, nodes and (unweighted) edges are grouped to supernodes and superedges, respectively, to obtain a smaller graph. We propose models and algorithms for weighted graphs. The interpretation (i.e. decompression) of a compressed, weighted graph is that a pair of original nodes is connected by an edge if their supernodes are connected by one, and that the weight of an edge is approximated to be the weight of the superedge. The compression problem now consists of choosing supernodes, superedges, and superedge weights so that the approximation error is minimized while the amount of compression is maximized. In this paper, we formulate this task as the 'simple weighted graph compression problem'. We then propose a much wider class of tasks under the name of 'generalized weighted graph compression problem'. The generalized task extends the optimization to preserve longer-range connectivities between nodes, not just individual edge weights. We study the properties of these problems and propose a range of algorithms to solve them, with dierent balances between complexity and quality of the result. We evaluate the problems and algorithms experimentally on real networks. The results indicate that weighted graphs can be compressed efficiently with relatively little compression error.

Role of feedback in mammalian vision: a new hypothesis and a computational model

This paper presents a novel hypothesis on the function of massive feedback pathways in mammalian visual systems. We propose that the cortical feature detectors compete not for the right to represent the output at a point, but for exclusive rights to abstract and represent part of the underlying input. Feedback can do this very naturally. A computational model that implements the above idea for the problem of line detection is presented and based on that we suggest a functional role for the thalamo-cortical loop during perception of lines. We show that the model successfully tackles the so called Cross problem. Based on some recent experimental results, we discuss the biological plausibility of our model. We also comment on the relevance of our hypothesis (on the role of feedback) to general sensory information processing and recognition. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.

Scalable Context-Sensitive Points-To Analysis Using Multi-Dimensional Bloom Filters

Context-sensitive points-to analysis is critical for several program optimizations. However, as the number of contexts grows exponentially, storage requirements for the analysis increase tremendously for large programs, making the analysis non-scalable. We propose a scalable flow-insensitive context-sensitive inclusion-based points-to analysis that uses a specially designed multi-dimensional bloom filter to store the points-to information. Two key observations motivate our proposal: (i) points-to information (between pointer-object and between pointer-pointer) is sparse, and (ii) moving from an exact to an approximate representation of points-to information only leads to reduced precision without affecting correctness of the (may-points-to) analysis. By using an approximate representation a multi-dimensional bloom filter can significantly reduce the memory requirements with a probabilistic bound on loss in precision. Experimental evaluation on SPEC 2000 benchmarks and two large open source programs reveals that with an average storage requirement of 4MB, our approach achieves almost the same precision (98.6%) as the exact implementation. By increasing the average memory to 27MB, it achieves precision upto 99.7% for these benchmarks. Using Mod/Ref analysis as the client, we find that the client analysis is not affected that often even when there is some loss of precision in the points-to representation. We find that the NoModRef percentage is within 2% of the exact analysis while requiring 4MB (maximum 15MB) memory and less than 4 minutes on average for the points-to analysis. Another major advantage of our technique is that it allows to trade off precision for memory usage of the analysis.

Exploiting the Structure of the Constraint Graph for Efficient Points-to Analysis

Points-to analysis is a key compiler analysis. Several memory related optimizations use points-to information to improve their effectiveness. Points-to analysis is performed by building a constraint graph of pointer variables and dynamically updating it to propagate more and more points-to information across its subset edges. So far, the structure of the constraint graph has been only trivially exploited for efficient propagation of information, e.g., in identifying cyclic components or to propagate information in topological order. We perform a careful study of its structure and propose a new inclusion-based flow-insensitive context-sensitive points-to analysis algorithm based on the notion of dominant pointers. We also propose a new kind of pointer-equivalence based on dominant pointers which provides significantly more opportunities for reducing the number of pointers tracked during the analysis. Based on this hitherto unexplored form of pointer-equivalence, we develop a new context-sensitive flow-insensitive points-to analysis algorithm which uses incremental dominator update to efficiently compute points-to information. Using a large suite of programs consisting of SPEC 2000 benchmarks and five large open source programs we show that our points-to analysis is 88% faster than BDD-based Lazy Cycle Detection and 2x faster than Deep Propagation. We argue that our approach of detecting dominator-based pointer-equivalence is a key to improve points-to analysis efficiency.

Prioritizing constraint evaluation for efficient points-to analysis

Pervasive use of pointers in large-scale real-world applications continues to make points-to analysis an important optimization-enabler. Rapid growth of software systems demands a scalable pointer analysis algorithm. A typical inclusion-based points-to analysis iteratively evaluates constraints and computes a points-to solution until a fixpoint. In each iteration, (i) points-to information is propagated across directed edges in a constraint graph G and (ii) more edges are added by processing the points-to constraints. We observe that prioritizing the order in which the information is processed within each of the above two steps can lead to efficient execution of the points-to analysis. While earlier work in the literature focuses only on the propagation order, we argue that the other dimension, that is, prioritizing the constraint processing, can lead to even higher improvements on how fast the fixpoint of the points-to algorithm is reached. This becomes especially important as we prove that finding an optimal sequence for processing the points-to constraints is NP-Complete. The prioritization scheme proposed in this paper is general enough to be applied to any of the existing points-to analyses. Using the prioritization framework developed in this paper, we implement prioritized versions of Andersen's analysis, Deep Propagation, Hardekopf and Lin's Lazy Cycle Detection and Bloom Filter based points-to analysis. In each case, we report significant improvements in the analysis times (33%, 47%, 44%, 20% respectively) as well as the memory requirements for a large suite of programs, including SPEC 2000 benchmarks and five large open source programs.

The effect of cell size and channel density on neuronal information encoding and energy efficiency

Identifying the determinants of neuronal energy consumption and their relationship to information coding is critical to understanding neuronal function and evolution. Three of the main determinants are cell size, ion channel density, and stimulus statistics. Here we investigate their impact on neuronal energy consumption and information coding by comparing single-compartment spiking neuron models of different sizes with different densities of stochastic voltage-gated Na+ and K+ channels and different statistics of synaptic inputs. The largest compartments have the highest information rates but the lowest energy efficiency for a given voltage-gated ion channel density, and the highest signaling efficiency (bits spike(-1)) for a given firing rate. For a given cell size, our models revealed that the ion channel density that maximizes energy efficiency is lower than that maximizing information rate. Low rates of small synaptic inputs improve energy efficiency but the highest information rates occur with higher rates and larger inputs. These relationships produce a Law of Diminishing Returns that penalizes costly excess information coding capacity, promoting the reduction of cell size, channel density, and input stimuli to the minimum possible, suggesting that the trade-off between energy and information has influenced all aspects of neuronal anatomy and physiology.

Functional analysis of ultra high information rates conveyed by rat vibrissal primary afferents

Sensory receptors determine the type and the quantity of information available for perception. Here, we quantified and characterized the information transferred by primary afferents in the rat whisker system using neural system identification. Quantification of ``how much'' information is conveyed by primary afferents, using the direct method (DM), a classical information theoretic tool, revealed that primary afferents transfer huge amounts of information (up to 529 bits/s). Information theoretic analysis of instantaneous spike-triggered kinematic stimulus features was used to gain functional insight on ``what'' is coded by primary afferents. Amongst the kinematic variables tested-position, velocity, and acceleration-primary afferent spikes encoded velocity best. The other two variables contributed to information transfer, but only if combined with velocity. We further revealed three additional characteristics that play a role in information transfer by primary afferents. Firstly, primary afferent spikes show preference for well separated multiple stimuli (i.e., well separated sets of combinations of the three instantaneous kinematic variables). Secondly, neurons are sensitive to short strips of the stimulus trajectory (up to 10 ms pre-spike time), and thirdly, they show spike patterns (precise doublet and triplet spiking). In order to deal with these complexities, we used a flexible probabilistic neuron model fitting mixtures of Gaussians to the spike triggered stimulus distributions, which quantitatively captured the contribution of the mentioned features and allowed us to achieve a full functional analysis of the total information rate indicated by the DM. We found that instantaneous position, velocity, and acceleration explained about 50% of the total information rate. Adding a 10 ms pre-spike interval of stimulus trajectory achieved 80-90%. The final 10-20% were found to be due to non-linear coding by spike bursts.

O sigilo bancário no inquérito parlamentar na Câmara dos Deputados

A tensão existente entre o direito à investigação do Poder Legislativo e as garantias constitucionais dos investigados, durante o processo de produção de provas concernentes à quebra de sigilo bancário, reclamava a realização de pesquisa que identificasse a origem dessa prerrogativa das CPIs e que descrevesse as suas principais características, bem como os usos que se fazem das informações sobre as movimentações bancárias dos investigados. Assim, analisaram-se os requerimentos de quebra de sigilo e os relatórios da CPI do Narcotráfico e daquelas comissões constituídas durante a 52ª legislatura. Constatou-se, com isso, que a referida prerrogativa foi concebida no âmbito da Câmara dos Deputados, em 1964, e que o principal uso dessas informações se referiu à fundamentação dos indiciamentos sugeridos ao Ministério Público. Em alguns deles, a quebra de sigilo ocorreu de forma indireta e incidental, na medida em que as informações bancárias de um outro investigado revelaram o envolvimento daqueles. Porém, determinados indiciamentos prescindiram da análise das informações bancárias dos investigados. Constatou-se, ainda, que o relatório final manteve-se silente no que se refere ao uso das informações bancárias de determinados investigados, não fazendo sobre eles qualquer menção.

Information access survey: Western Visayas, Philippines

The aim of this report is to provide brief profiles of the main stakeholders within the aquatic resources and fisheries sectors in Western Visayas, to describe their access to information, and the communication between and within stakeholder groups, organizations and institutions within the sector. The report goes on to identify current needs and key action points which might maximize efficient communication. (PDF contains 68 pages)

Do encontro ao sentido: o cuidado aos sujeitos adoecidos de câncer

Esta pesquisa objetivou compreender como se dão as práticas de cuidado dirigidas ao sujeito adoecido de câncer no cotidiano dos serviços de saúde. Para tanto, partimos do entendimento que o processo de adoecer traz repercussões nos modos de andar a vida dos sujeitos, especialmente no que diz respeito ao câncer, patologia que traz consigo metáforas ligadas à morte, sofrimento e dor. Ao dar início à busca pelos serviços de saúde, os sujeitos se deparam com uma série de entraves que podem não proporcionar alívio, não suprindo as necessidades que essa nova condição impõe. Encontramos, em muitos momentos, práticas que negam o caráter subjetivo da experiência da doença, não valorizando a narrativa dos sujeitos. Como trajetória metodológica, escolhemos desenvolver um estudo de natureza qualitativa, utilizando como instrumento privilegiado a entrevista semi aberta. Iniciamos as entrevistas com a consigna: conte como se deu o tratamento de sua doença desde a descoberta até o momento em que se encontra. Os dados coletados a partir do encontro com os sujeitos adoecidos foram complementados por informações contidas nos prontuários médicos, bem como por observações obtidas no momento da interação. O local de realização da pesquisa foi um hospital estadual de grande porte localizado na cidade de Fortaleza, estado do Ceará. As entrevistas foram realizadas no serviço de oncologia clínica do referido hospital. Ao todo foram entrevistados doze sujeitos que estavam em tratamento ambulatorial no serviço. Dos doze sujeitos, cinco eram mulheres e sete eram homens. As idades variaram de 29 a 65 anos. A análise dos dados se deu após imersão no material empírico, posteriormente materializado nas transcrições das entrevistas. Procuramos deixar que os sentidos aflorassem, confrontando com o material que já tínhamos disponível, surgindo daí as categorias empíricas. Dividimos as categorias em duas dimensões, a do sujeito e a da rede de serviços de saúde. Ao final da análise, constatamos alguns pontos que consideramos importantes no sentido de se tornarem dispositivos de mudança. Foi possível confirmar que os sujeitos sabem de si, e realizam um processo de construção do sentido sobre sua doença e das práticas terapêuticas. A doença produz mudanças no sujeito, e os força a ressignificarem sua rotina e hábitos de vida. Foi possível observar que o encontro com os serviços de saúde tem se dado de forma truncada. A luta pelo direito a saúde é árdua: pela demora na confirmação do diagnóstico, pela demora em conseguir marcar exames e receber seus resultados, pela falta de especialistas que saibam o que estão fazendo. Os sujeitos têm descoberto a doença quando esta se encontra avançada. A importância do diálogo, da escuta, da percepção do que o outro necessita é importante, por isso, valorizar os relatos dos sujeitos adoecidos de câncer se faz urgente.

Os efeitos da cidade digital: o direito à privacidade e à liberdade de informação

O presente trabalho analisa a formação da cidade digital nas relações sociais, ressaltando os efeitos da garantia do direito à privacidade no ambiente dos navegantes de sites e redes sociais, em função das repercussões jurídicas do vazamento de informações da vida pessoal dos usuários da rede, e do tratamento dos dados coletados pelos prestadores de serviço. Através do ciberespaço formam-se comunidades virtuais que ultrapassam a necessidade de localidade e sociabilidade, criando um isolamento social e abandonando as interações face a face em ambientes reais, originando uma sociabilidade baseada no individualismo. Avaliamos os novos padrões de interação que se originam nesta nova formatação de coletividade informacional e suas repercussões no âmbito do direito. Em uma perspectiva mais detalhada, esse estudo indica quais as hipóteses de responsabilidade civil dos provedores na Internet em decorrência de atos ilícitos cometidos por terceiros e as alternativas de um sistema de tutela da privacidade à proteção de dados, face à lesão no ambiente informacional. O levantamento das possíveis situações de responsabilização civil foi efetuado através da análise da jurisprudência e da doutrina dominante, ressaltando os aspectos fáticos que caracterizam sua formatação. Esse modelo se impõe, através de uma relação hierárquica a uma multiplicidade de indivíduos, criando um encarceramento perfeito através do exercício do biopoder. Tais papéis são reforçados por uma cultura consumista e a sociedade do espetáculo, que transforma o indivíduo em mercadoria levantando perfis de usuários conectados em rede, propiciando uma categorização dos consumidores. Nesse contexto, apresentamos os riscos de uma sociedade de vigilância que se apresenta factível como um produto das relações de mercado, que possibilita dispor livremente de um conjunto crescente de informações. Esta constante vigilância invade todos os espaços, custodiando nosso comportamento independente do tempo, com uma implacável memória no âmbito das comunicações eletrônicas, tornando nosso passado eternamente visível e fazendo surgir situações constrangedoras a nos assombrar.

Promoção de Segurança Alimentar e Nutricional na Estratégia Saúde da Família: uma aproximação a partir da escuta de diferentes atores sociais

A garantia de Segurança Alimentar e Nutricional (SAN) remete à necessidade de ações intersetoriais que articulem as dimensões alimentar e nutricional, além da questão contemporânea da sustentabilidade e da perspectiva do direito humano à alimentação adequada. O setor saúde tem funções específicas e importantes que contribuem para o conjunto das políticas de governo voltadas para a garantia da SAN a população. Desta forma, ações promotoras de SAN devem ser desenvolvidas em todos os níveis de atenção do Sistema Único de Saúde, sendo a Atenção Básica à Saúde, por meio da Estratégia Saúde da Família (ESF), um campo privilegiado de implementação dessas ações, uma vez que está configurada como a porta preferencial de entrada dos usuários no sistema de saúde e como o centro norteador da rede de assistência. Este é um estudo exploratório e descritivo de abordagem qualitativa que teve como objetivo conhecer o que profissionais de equipes de saúde da Família, gestores dos âmbitos federal e municipal ligados à ESF, além de representantes de organizações da sociedade civil atuantes no campo da SAN entendem sobre SAN e sobre práticas promotoras de SAN na ESF. A construção das informações ocorreu por meio de entrevistas semi-estruturadas e grupos focais. Os profissionais referiram-se a SAN como a garantia de uma alimentação que atenda às necessidades nutricionais e que seja segura para o consumo, enquanto que entre os representantes da sociedade civil organizada e gestores predominou uma compreensão mais ampla da SAN. Os diferentes atores identificaram a ESF com um espaço promotor de SAN a partir do levantamento de ações já desenvolvidas ou que possam vir a ser desenvolvidas, porém as ações citadas encontram-se majoritariamente ligadas à dimensão nutricional da SAN. Os atores referiram um conjunto de problemas estruturais que desencadeiam dificuldades no cotidiano da organização dos serviços e das práticas dos profissionais e consequentemente na execução de ações promotoras de SAN nessa estratégia. Este trabalho levantou a necessidade de difundir a interdependência entre saúde e SAN entre gestores e profissionais ligados à ESF para que estes possam identificar melhor nas ações dos serviços de saúde elementos promotores da SAN, e desta forma compreender seu papel de agentes promotores de saúde e SAN.