31,418 research outputs found
Speech and language therapy for aphasia following stroke
Background Aphasia is an acquired language impairment following brain damage that affects some or all language modalities: expression and understanding of speech, reading, and writing. Approximately one third of people who have a stroke experience aphasia. Objectives To assess the effects of speech and language therapy (SLT) for aphasia following stroke. Search methods We searched the Cochrane Stroke Group Trials Register (last searched 9 September 2015), CENTRAL (2015, Issue 5) and other Cochrane Library Databases (CDSR, DARE, HTA, to 22 September 2015), MEDLINE (1946 to September 2015), EMBASE (1980 to September 2015), CINAHL (1982 to September 2015), AMED (1985 to September 2015), LLBA (1973 to September 2015), and SpeechBITE (2008 to September 2015). We also searched major trials registers for ongoing trials including ClinicalTrials.gov (to 21 September 2015), the Stroke Trials Registry (to 21 September 2015), Current Controlled Trials (to 22 September 2015), and WHO ICTRP (to 22 September 2015). In an effort to identify further published, unpublished, and ongoing trials we also handsearched theInternational Journal of Language and Communication Disorders(1969 to 2005) and reference lists of relevant articles, and we contacted academic institutions and other researchers. There were no language restrictions. Selection criteria Randomised controlled trials (RCTs) comparing SLT (a formal intervention that aims to improve language and communication abilities, activity and participation) versus no SLT; social support or stimulation (an intervention that provides social support and communication stimulation but does not include targeted therapeutic interventions); or another SLT intervention (differing in duration, intensity, frequency, intervention methodology or theoretical approach). Data collection and analysis We independently extracted the data and assessed the quality of included trials. We sought missing data from investigators. Main results We included 57 RCTs (74 randomised comparisons) involving 3002 participants in this review (some appearing in more than one comparison). Twenty-seven randomised comparisons (1620 participants) assessed SLT versus no SLT; SLT resulted in clinically and statistically significant benefits to patients' functional communication (standardised mean difference (SMD) 0.28, 95% confidence interval (CI) 0.06 to 0.49, P = 0.01), reading, writing, and expressive language, but (based on smaller numbers) benefits were not evident at follow-up. Nine randomised comparisons (447 participants) assessed SLT with social support and stimulation; meta-analyses found no evidence of a difference in functional communication, but more participants withdrew from social support interventions than SLT. Thirty-eight randomised comparisons (1242 participants) assessed two approaches to SLT. Functional communication was significantly better in people with aphasia that received therapy at a high intensity, high dose, or over a long duration compared to those that received therapy at a lower intensity, lower dose, or over a shorter period of time. The benefits of a high intensity or a high dose of SLT were confounded by a significantly higher dropout rate in these intervention groups. Generally, trials randomised small numbers of participants across a range of characteristics (age, time since stroke, and severity profiles), interventions, and outcomes. Authors' conclusions Our review provides evidence of the effectiveness of SLT for people with aphasia following stroke in terms of improved functional communication, reading, writing, and expressive language compared with no therapy. There is some indication that therapy at high intensity, high dose or over a longer period may be beneficial. HIgh-intensity and high dose interventions may not be acceptable to all
Active Sampling for Large-scale Information Retrieval Evaluation
Evaluation is crucial in Information Retrieval. The development of models,
tools and methods has significantly benefited from the availability of reusable
test collections formed through a standardized and thoroughly tested
methodology, known as the Cranfield paradigm. Constructing these collections
requires obtaining relevance judgments for a pool of documents, retrieved by
systems participating in an evaluation task; thus involves immense human labor.
To alleviate this effort different methods for constructing collections have
been proposed in the literature, falling under two broad categories: (a)
sampling, and (b) active selection of documents. The former devises a smart
sampling strategy by choosing only a subset of documents to be assessed and
inferring evaluation measure on the basis of the obtained sample; the sampling
distribution is being fixed at the beginning of the process. The latter
recognizes that systems contributing documents to be judged vary in quality,
and actively selects documents from good systems. The quality of systems is
measured every time a new document is being judged. In this paper we seek to
solve the problem of large-scale retrieval evaluation combining the two
approaches. We devise an active sampling method that avoids the bias of the
active selection methods towards good systems, and at the same time reduces the
variance of the current sampling approaches by placing a distribution over
systems, which varies as judgments become available. We validate the proposed
method using TREC data and demonstrate the advantages of this new method
compared to past approaches
Inventory Signals
How does operational competence translate into market value, when firms cannot credibly communicate their competence to the market? I consider the example of inventory and fill rates. When the market sees a high-inventory firm, it cannot tell whether the inventory is due to incompetence or a strategy to enhance fill rate. Firms might decide to signal their competence to the market by carrying less inventory. I show conditions for separating and pooling perfect Bayesian equilibria. I also provide empirical evidence for this theory that inventory has a signaling role. The theory could potentially provide a framework that describes one way in which a range of operational competences such as purchasing and outsourcing, translate to market value. Practically, it has implications for firms, such as how to strategically communicate to the market, reward managers, or even whether to go public and be subject to market pressures.Inventory; signaling; operations management; asymmetric information
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