In three experiments, pigeons were trained to discriminate between uniform arrays of two elements that differed in color, form, or size. They were then tested with arrays that contained different proportions ofthe two elements on these dimensions. In all cases, orderly discrimination gradients reflected these proportions. The discrimination readily transferred to new arrays with similar stimuli, but with different total numbers of elements. In Experiment 4, the pigeons were taught to discriminate between two groups of categorical stimuli: pictures of birds and pictures of flowers. A test with different proportions of each again produced a gradient based on relative numerosity. Experiment 5 demonstrated transfer of stimulus control on the numerosity dimension when pigeons were trained with one set of instances from two categories, and then were tested with new instances from the same categories.In a thoughtful and thorough review of research on counting in animals, Davis and Memmott (1982) distinguished between number discrimination and counting.Counting involves a precise tagging of each item in a display or a sequence of events, and a partitioning of items to distinguish between those already counted and those that remain to be counted. Convincing evidence for these processes in animals is sparse, and even when it can be found, the number of items or events that animals can count reliably does not extend much beyond three or four. Most species do not seem to possess the symbolic capacity required to enumerate the individual items in an array. Number discrimination, on the other hand, does not involve the rigorous criteria of true counting: this process refers to an organism's ability to make broad relative judgments such as many versus few. Such judgments are occasionally referred to as "numerosity judgments" or "magnitude estimations." The important point is that number discrimination is an essentially imprecise ability that is not as advanced as counting. (Davis & Memmott, 1982, pp. 548-549) Although this is a useful and important distinction, Davis and Memmott did not further discuss the topic of number discrimination. They devoted the rest of their review to counting. This suggests that there has been little research on the discrimination of numerosity, as distinguished from counting.The imprecise nature of numerosity discriminations (as we will call them) may discourage psychologists from analyzing them experimentally. However, the apparent numerosity of objects in a spatial array is no doubt important for many animals and birds. It is useful to be able to discriminate the size of a group or a flock of other animals, the density of trees in a particular area, or the relative numbers of ripe and unripe berries on a branch. As shown by recent research on concept attainment, pigeons readily classify items within several different categories

BackgroundIn response to increased global public health funding initiatives to HIV/AIDS care in Africa, this study aimed to describe practice models, strategies and challenges to delivering end-of-life care in sub-Saharan Africa.MethodsA survey end-of-life care programs was conducted, addressing the domains of service aims and configuration, barriers to pain control, governmental endorsement and strategies, funding, monitoring and evaluation, and research. Both closed and qualitative responses were sought.ResultsDespite great structural challenges, data from 48 programs in 14 countries with a mean annual funding of US $374,884 demonstrated integrated care delivery across diverse settings. Care was commonly integrated with all advanced disease care (67%) and disease stages (65% offering care from diagnosis). The majority (98%) provided home-based care for a mean of 301 patients. Ninety-four percent reported challenges in pain control (including availability, lack of trained providers, stigma and legal restrictions), and 77% addressed the effects of poverty on disease progression and management. Although 85% of programs reported Government endorsement, end-of-life and palliative care National strategies were largely absent.ConclusionsThe interdependent tasks of expanding pain control, balancing quality and coverage of care, providing technical assistance in monitoring and evaluation, collaborating between donor agencies and governments, and educating policy makers and program directors of end-of-life care are all necessary if resources are to reach their goals.

Background & Aims Weight management is a cornerstone of treatment for overweight/obese persons with non-alcoholic fatty liver disease (NAFLD). This exploratory study sought to: (i) evaluate readiness to change weight-related behaviours; (ii) assess psychosocial characteristics that may interfere with weight loss; and (iii) evaluate how baseline psychosocial features associate with 6-month change in weight in persons with NAFLD receiving standard medical care. The purpose of this investigation was to develop hypotheses regarding relationships between psychosocial factors and weight for use in future fully powered studies and clinical interventions Methods Fifty-eight overweight/obese participants with NAFLD completed baseline measures of personality, psychiatric symptoms and readiness for behaviour change and were followed up for 6 months in standard care. Results One-third of participants (31.0%) were not interested in making weight-related behaviour changes; 58.6% were considering making a change, and 10.4% of individuals were actively working on or preparing to change. Six-month change in weight was non-significant and was not associated with baseline readiness for change. Depression, low conscientiousness and high neuroticism were associated with higher weight at 6-month follow-up with small to large effect sizes. Conclusions Although participants received nutritional education and guidance, very few individuals presented in the active stage of change. Although readiness for change did not predict subsequent change in weight, personality factors and psychiatric symptoms were associated with weight outcomes. Integrated multidisciplinary approaches that address psychiatric needs and provide behavioural support for weight loss may help patients with NAFLD implement sustained lifestyle changes.

Cognitive difficulties manifested by the growing elderly population with cirrhosis could be amnestic (memory-related) or non-amnestic (memory-unrelated). The underlying neuro-biological and gut-brain changes are unclear in this population. We aimed to define gut-brain axis alterations in elderly cirrhotics compared to non-cirrhotic individuals based on presence of cirrhosis and on neuropsychological performance. Age-matched outpatients with/without cirrhosis underwent cognitive testing (amnestic/non-amnestic domains), quality of life (HRQOL), multi-modal MRI (fMRI go/no-go task, volumetry and MR spectroscopy), blood (inflammatory cytokines) and stool collection (for microbiota). Groups were studied based on cirrhosis/not and also based on neuropsychological performance (amnestic-type, amnestic/non-amnestic-type and unimpaired). Cirrhotics were impaired on non-amnestic and selected amnestic tests, HRQOL and systemic inflammation compared to non-cirrhotics. Cirrhotics demonstrated significant changes on MR spectroscopy but not on fMRI or volumetry. Correlation networks showed that Lactobacillales members were positively while Enterobacteriaceae and Porphyromonadaceae were negatively linked with cognition. Using the neuropsychological classification amnestic/non-amnestic-type individuals were majority cirrhosis and had worse HRQOL, higher inflammation and decreased autochthonous taxa relative abundance compared to the rest. This classification also predicted fMRI, MR spectroscopy and volumetry changes between groups. We conclude that gut-brain axis alterations may be associated with the type of neurobehavioral decline or inflamm-aging in elderly cirrhotic subjects.