Collocating Interface Objects: Zooming into Maps

May, Dean and Barnard [10] used a theoretically based model to argue that objects in a wide range of interfaces should be collocated following screen changes such as a zoom-in to detail. Many existing online maps do not follow this principle, but move a clicked point to the centre of the subsequent display, leaving the user looking at an unrelated location. This paper presents three experiments showing that collocating the point clicked on a map so that the detailed location appears in the place previously occupied by the overview location makes the map easier to use, reducing eye movements and interaction duration. We discuss the benefit of basing design principles on theoretical models so that they can be applied to novel situations, and so designers can infer when to use and not use them

Paying attention to meaning

Several paradigms show that responses to one event compromise responses to a second event for around 500 ms. Such effects are generally attributed to attentional capacity limitations associated with processing information in the first event. In a task in which targets could be distinguished only by their meaning, we varied the semantic relationship between distractors and targets following at different lags. Semantic relatedness alone produced a classic attentional blink. We conclude by discussing how attention theory might best accommodate these new effects

Mitral valve replacement at Tygerberg Hospital: a 5 year follow-up

This study provides 5-year follow-up data of isolated mitral valve replacements with mechanical prosthesis at a large South African tertiary hospital. It also assessed the significance of pre-operative parameters to predict mortality. This is a retrospective study of 187 patients that underwent isolated mitral valve replacement at Tygerberg Hospital from Jan 1998-Dec 2002. Twenty seven patient’s data was incomplete and they were excluded from the study. All patients had rheumatic mitral valve disease and the valve lesions included mitral incompetence, mitral stenosis and mixed mitral valve disease. All patients had a mechanical prosthesis implanted (St Jude medical or Orbis bileaflet valves). The mean follow-up time was 5.41-years. The 30 day mortality was 5.62% and the 5-year survival was 80%. Pre-operative risk factors that significantly increased mortality were pulmonary hypertension and mitral stenosis. Valve-related complications were more common in this series compared to other First World populations but our results compare well with other Third World population groups. Valve thrombosis 4.32% (0.8%/yr), thromboembolism 8.71% (1.61%/yr), anticoagulant related haemorrhage 6.87% (1.27%/yr), prosthetic valve endocarditis 3.08% (0.57%/yr) and re-operation 8.12% (1.5%/yr).Conclusion: Mechanical valve replacement for mitral valve disease that requires valve replacement is still a good treatment option even in third world population groups. In our series, severe pulmonary hypertension, mitral stenosis and reoperation was statistically significantly more common in the “non-survivors” group

The effect of heterosexual contact on libido and mating dexterity in Karakul rams

No Abstrac

Systems, interactions and macrotheory

A significant proportion of early HCI research was guided by one very clear vision: that the existing theory base in psychology and cognitive science could be developed to yield engineering tools for use in the interdisciplinary context of HCI design. While interface technologies and heuristic methods for behavioral evaluation have rapidly advanced in both capability and breadth of application, progress toward deeper theory has been modest, and some now believe it to be unnecessary. A case is presented for developing new forms of theory, based around generic “systems of interactors.” An overlapping, layered structure of macro- and microtheories could then serve an explanatory role, and could also bind together contributions from the different disciplines. Novel routes to formalizing and applying such theories provide a host of interesting and tractable problems for future basic research in HCI

Epidemiological reference ranges for low-density lipoprotein cholesterol and apolipoprotein B for identification of increased risk of ischaemic heart disease

Although there is widespread acceptance that total cholesterol (TC) value reference ranges should be based on epidemiological rather than statistical considerations, the epidemiological action limits for Iow-density lipoprotein cholesterol (LDL-C) are still incomplete and only statistical reference ranges for apolipoprotein B (Apo-B) levels are available. The combined use of epidemiological reference ranges for TC and incomplete or statistical reference ranges for LDL-C and Apo-B is illogical, since these parameters may fall into discordant risk categories that will hamper and complicate the management of hypercholesterolaemia. Based on a study of Iipograms obtained from ± 3 000 inhabitants of two industrialised Transvaal towns, the agerelated epidemiological reference ranges for LDL-C and ApoB were established. A comparison with published observational studies of other populations, in which comparable lipid, lipoprotein and apolipoprotein methodologies were used, reflected the severity of these lipid-related abnormalities in white South Africans, especially after the age of 30 years. In addition, the serum TC values found in this survey were not significantly different from those obtained 10 years ago

The changing face of human-computer interaction in the age of ubiquitous computing

HCI is reinventing itself. No longer only about being user centered, it has set its sights on pastures new, embracing a much broader and far-reaching set of interests. From emotional, eco-friendly, embodied experiences to context, constructivism and culture, HCI research is changing apace: from what it looks at, the lenses it uses and what it has to offer. Part of this is as a reaction to what is happening in the world; ubiquitous technologies are proliferating and transforming how we live our lives. We are becoming more connected and more dependent on technology. The home, the crèche, outdoors, public places and even the human body are now being experimented with as potential places to embed computational devices, even to the extent of invading previously private and taboo aspects of our lives. In this paper, I examine the diversity of lifestyle and technological transformations in our midst and outline some 'difficult' questions these raise together with alternative directions for HCI research and practice

‘O sibling, where art thou?’ – a review of avian sibling recognition with respect to the mammalian literature

Avian literature on sibling recognition is rare compared to that developed by mammalian researchers. We compare avian and mammalian research on sibling recognition to identify why avian work is rare, how approaches differ and what avian and mammalian researchers can learn from each other. Three factors: (1) biological differences between birds and mammals, (2) conceptual biases and (3) practical constraints, appear to influence our current understanding. Avian research focuses on colonial species because sibling recognition is considered adaptive where ‘mixing potential’ of dependent young is high; research on a wider range of species, breeding systems and ecological conditions is now needed. Studies of acoustic recognition cues dominate avian literature; other types of cues (e.g. visual, olfactory) deserve further attention. The effect of gender on avian sibling recognition has yet to be investigated; mammalian work shows that gender can have important influences. Most importantly, many researchers assume that birds recognise siblings through ‘direct familiarisation’ (commonly known as associative learning or familiarity); future experiments should also incorporate tests for ‘indirect familiarisation’ (commonly known as phenotype matching). If direct familiarisation proves crucial, avian research should investigate how periods of separation influence sibling discrimination. Mammalian researchers typically interpret sibling recognition in broad functional terms (nepotism, optimal outbreeding); some avian researchers more successfully identify specific and testable adaptive explanations, with greater relevance to natural contexts. We end by reporting exciting discoveries from recent studies of avian sibling recognition that inspire further interest in this topic

Reduced specificity of autobiographical memory and depression: The role of executive control

It has been widely established that depressed mood states and clinical depression, as well as a range of other psychiatric disorders, are associated with a relative difficulty in accessing specific autobiographical information in response to emotion-related cue words on an Autobiographical Memory Test (AMT; J. M. G. Williams & K. Broadbent, 1986). In 8 studies the authors examined the extent to which this relationship is a function of impaired executive control associated with these mood states and clinical disorders. Studies 1-4 demonstrated that performance on the AMT is associated with performance on measures of executive control, independent of depressed mood. Furthermore, Study 1 showed that executive control (as measured by verbal fluency) mediated the relationship between both depressed mood and a clinical diagnosis of eating disorder and AMT performance. Using a stratified sample in Study 5, the authors confirmed the positive association between depressed mood and impaired performance on the AMT. Studies 6-8 involved experimental manipulations of the parameters of the AMT designed to further indicate that reduced executive control is to a significant extent driving the relationship between depressed mood and AMT performance. The potential role of executive control in accounting for other aspects of the AMT literature is discussed. (PsycINFO Database Record (c) 2007 APA, all rights reserved)

The Opportunity Cost of the Conservation Reserve Program: A Kansas Land Example

The effects of the Conservation Reserve Program (CRP) on farmland values is investigated using a set of parcel-level data for land sales in Kansas over the period 1998 to 2014. The sales data are used to estimate a hedonic model of land values that allows for the opportunity cost of CRP enrollment to vary across space and time. Factors impacting the opportunity costs include the relative productivity of land, returns to farming, and the time remaining under the CRP contracts. We find that the discount associated with having land under CRP contract averages 7%