Medium-term follow-up of Crohn's disease in Cape Town

The 82 cases of Crohn's disease diagnosed in Greater Cape Town between 1970 and 1979 were followed up after a median time. of 9,6 years from diagnosis. Sixty patients were contacted; 6 had died and 16 were not available for followup. Only 1 death was disease-related. Mortality in Crohn's disease was not increased. There were no cases of carcinoma of the colon. At diagnosis most patients had had moderately severe disease, and 10 years later, 80% had mild-to-moderate symptoms. The 5-year resection rate was 46% and the 10-year rate 68%; 23% of patients required a second resection within 5 years of the first, and 42% within 10 years. Surgery occurred earlier in those with ileitis. Ten patients were over the age of 60 years at diagnosis; there was no apparent difference between the extent of their disease and that in the group as a whole. However, the elderly patients appeared to have a better prognosis - 59% having been symptom-free for more than 1 year, and none having required a second resection.S Afr Med J 1989; 76: 139-14

Medium-term follow-up of ulcerative colitis in Cape Town

The 114 patients with ulcerative colitis diagnosed in Greater Cape Town between 1970 and 1979 were followed up 11 years later. Ninety per cent of those contacted were in remission or had mild symptoms only. Eleven patients had died; 3 deaths (in total colitis patients) were disease-related but the overall mortality rate in ulcerative colitis was not increased. There was only 1 case of carcinoma of the colon. The 5-year surgical rate was 5% increasing to 23% 10 years after diagnosis. Six patients (35%) had had a Park's pouch, 3 (18%) ileorectal anastomosis, and a (47%) panproctocolectomy or colectomy with an ileostomy. The incidence of surgery was higher in those with total colitis. In those patients who did not have the rectum removed, there was a 100% recurrence of proctitis. Park's pouch patients remained well and incontinence was not a problem. Thirty-one per cent of patients with proctitis at diagnosis had evidence of extension of disease to the colon at follow-up. Ulcerative colitis may be a more benign disease than often believed, with mortality from the disease and need for surgery being associated almost exclusively with extensive disease.S Afr Med J 1989; 76: 142·14

Effectiveness of laxatives in elderly - a cross sectional study in nursing homes

<p>Abstract</p> <p>Background</p> <p>Laxatives are efficient drugs, but the effectiveness has been questioned. In nursing homes, the prevalence of constipation is high and laxatives are commonly used drugs. The aims of the study were to assess the effectiveness of laxative therapy in an everyday setting in Norwegian nursing homes, study differences between treatment regimens and factors associated with normal bowel function.</p> <p>Methods</p> <p>A cross-sectional study. After giving informed consent, residents above 60 years of age using laxatives for functional constipation were included, and their characteristics, medical history, use of drugs and bowel functions were recorded. Normal bowel function was defined as bowel movements from 3 times/week to 3 times/day and stool consistency 3-5 on Bristol Stool Form Scale.</p> <p>Results</p> <p>Out of 647 residents in the nursing homes, 197 were included and 116 (59%) had normal bowel function. The treatment effect did not differ significantly between the laxatives, treatment regimens or expected efficacy of the regimens. The treatment was unsatisfactorily adapted to individual needs. In subjects with normal bowel function, 113 (97%) had persistent complaints; 68 (59.5%), 10 (8.0%), 34 (28.6%) and 26 (22.5%) reported straining, manual manoeuvre to facilitate bowel movements, feeling of incomplete bowel movements, and feeling of anorectal obstruction respectively. Good nutritional status, previous or present cancer disease and anxiety/depression were predictors of normal bowel function.</p> <p>Conclusions</p> <p>Treatment of constipation in nursing homes was unsatisfactory. Nearly all patients with normal stool frequency and consistence had some persistent complaints. Improved nutrition and individualization of the treatment could improve the outcome.</p

Grid Cells, Place Cells, and Geodesic Generalization for Spatial Reinforcement Learning

Reinforcement learning (RL) provides an influential characterization of the brain's mechanisms for learning to make advantageous choices. An important problem, though, is how complex tasks can be represented in a way that enables efficient learning. We consider this problem through the lens of spatial navigation, examining how two of the brain's location representations—hippocampal place cells and entorhinal grid cells—are adapted to serve as basis functions for approximating value over space for RL. Although much previous work has focused on these systems' roles in combining upstream sensory cues to track location, revisiting these representations with a focus on how they support this downstream decision function offers complementary insights into their characteristics. Rather than localization, the key problem in learning is generalization between past and present situations, which may not match perfectly. Accordingly, although neural populations collectively offer a precise representation of position, our simulations of navigational tasks verify the suggestion that RL gains efficiency from the more diffuse tuning of individual neurons, which allows learning about rewards to generalize over longer distances given fewer training experiences. However, work on generalization in RL suggests the underlying representation should respect the environment's layout. In particular, although it is often assumed that neurons track location in Euclidean coordinates (that a place cell's activity declines “as the crow flies” away from its peak), the relevant metric for value is geodesic: the distance along a path, around any obstacles. We formalize this intuition and present simulations showing how Euclidean, but not geodesic, representations can interfere with RL by generalizing inappropriately across barriers. Our proposal that place and grid responses should be modulated by geodesic distances suggests novel predictions about how obstacles should affect spatial firing fields, which provides a new viewpoint on data concerning both spatial codes

Tracking Down Abstract Linguistic Meaning: Neural Correlates of Spatial Frame of Reference Ambiguities in Language

This functional magnetic resonance imaging (fMRI) study investigates a crucial parameter in spatial description, namely variants in the frame of reference chosen. Two frames of reference are available in European languages for the description of small-scale assemblages, namely the intrinsic (or object-oriented) frame and the relative (or egocentric) frame. We showed participants a sentence such as “the ball is in front of the man”, ambiguous between the two frames, and then a picture of a scene with a ball and a man – participants had to respond by indicating whether the picture did or did not match the sentence. There were two blocks, in which we induced each frame of reference by feedback. Thus for the crucial test items, participants saw exactly the same sentence and the same picture but now from one perspective, now the other. Using this method, we were able to precisely pinpoint the pattern of neural activation associated with each linguistic interpretation of the ambiguity, while holding the perceptual stimuli constant. Increased brain activity in bilateral parahippocampal gyrus was associated with the intrinsic frame of reference whereas increased activity in the right superior frontal gyrus and in the parietal lobe was observed for the relative frame of reference. The study is among the few to show a distinctive pattern of neural activation for an abstract yet specific semantic parameter in language. It shows with special clarity the nature of the neural substrate supporting each frame of spatial reference

Health-related quality of life in young adults with symptoms of constipation continuing from childhood into adulthood

<p>Abstract</p> <p>Background</p> <p>Children with functional constipation report impaired Health-related Quality of Life (HRQoL) in relation to physical complaints and long duration of symptoms. In about one third of children with constipation, symptoms continue into adulthood. Knowledge on HRQoL in adults with constipation persisting from childhood is lacking.</p> <p>Objectives</p> <p>To assess HRQoL in adults with constipation from early childhood in comparison to that of their peers. Furthermore to gain insight into the specific social consequences related to continuing symptoms of constipation and/or fecal incontinence at adult age.</p> <p>Methods</p> <p>One HRQoL questionnaire and one self-developed questionnaire focusing on specific consequences of symptoms of constipation continuing into adulthood were administrated to 182 adults with a history of childhood constipation. Successful clinical outcome was defined as a defecation frequency three or more times per week with less than two episodes of fecal incontinence per month, irrespective of laxative use. HRQoL of both adults with unsuccessful and successful clinical outcome were compared to a control group of 361 peers from the general Dutch population.</p> <p>Results</p> <p>No differences in HRQoL were found between the whole study population and healthy peers, nor between adults with successful clinical outcome (n = 139) and the control group. Adults with an unsuccessful clinical outcome (n = 43) reported significantly lower HRQoL compared to the control group with respect to scores on bodily pain (mean ± SD 77.4 ± 19.6 versus 85.7 ± 19.5, p = 0.01) and general health (67.6 ± 18.8 versus 74.0 ± 18.1, p = 0.04). Adults with an unsuccessful clinical outcome reported difficulties with social contact and intimacy (20% and 12.5%, respectively), related to their current symptoms. Current therapy in these adults was more often self-administered treatment (e.g. diet modifications) (60.4%) than laxatives (20.9%).</p> <p>Conclusion</p> <p>Overall, young adults with constipation in childhood report a good quality of life, as HRQoL of adults with successful clinical outcome was comparable to that of their peers. However, when childhood constipation continues into adulthood, it influences HRQoL negatively with social consequences in 20% of these adults.</p

Predation success by a plant-ant indirectly favours the growth and fitness of its host myrmecophyte

Mutualisms, or interactions between species that lead to net fitness benefits for each species involved, are stable and ubiquitous in nature mostly due to "byproduct benefits" stemming from the intrinsic traits of one partner that generate an indirect and positive outcome for the other. Here we verify if myrmecotrophy (where plants obtain nutrients from the refuse of their associated ants) can explain the stability of the tripartite association between the myrmecophyte Hirtella physophora, the ant Allomerus decemarticulatus and an Ascomycota fungus. The plant shelters and provides the ants with extrafloral nectar. The ants protect the plant from herbivores and integrate the fungus into the construction of a trap that they use to capture prey; they also provide the fungus and their host plant with nutrients. During a 9-month field study, we over-provisioned experimental ant colonies with insects, enhancing colony fitness (i.e., more winged females were produced). The rate of partial castration of the host plant, previously demonstrated, was not influenced by the experiment. Experimental plants showed higher δ¹⁵N values (confirming myrmecotrophy), plus enhanced vegetative growth (e.g., more leaves produced increased the possibility of lodging ants in leaf pouches) and fitness (i.e., more fruits produced and more flowers that matured into fruit). This study highlights the importance of myrmecotrophy on host plant fitness and the stability of ant-myrmecophyte mutualisms

Lessons learnt from comprehensive evaluation of community-based education in Uganda: a proposal for an ideal model community-based education for health professional training institutions

<p>Abstract</p> <p>Background</p> <p>Community-based education (CBE) can provide contextual learning that addresses manpower scarcity by enabling trainees acquire requisite experiences, competence, confidence and values. In Uganda, many health professional training institutions conduct some form of community-based education (CBE). However, there is scanty information on the nature of the training: whether a curriculum exists (objectives, intended outcomes, content, implementation strategy), administration and constraints faced. The objective was to make a comprehensive assessment of CBE as implemented by Ugandan health professional training institutions to document the nature of CBE conducted and propose an ideal model with minimum requirements for health professional training institutions in Uganda.</p> <p>Methods</p> <p>We employed several methods: documentary review of curricula of 22 institutions, so as to assess the nature, purpose, outcomes, and methods of instruction and assessment; s<it>ite visits </it>to these institutions and their CBE sites, to assess the learning environment (infrastructure and resources); in-depth interviews with key people involved in running CBE at the institutions and community, to evaluate CBE implementation, challenges experienced and perceived solutions.</p> <p>Results</p> <p>CBE was perceived differently ranging from a subject, a course, a program or a project. Despite having similar curricula, institutions differ in the administration, implementation and assessment of CBE. Objectives of CBE, the curricula content and implementation strategies differ in similar institutions. On collaborative and social learning, most trainees do not reside in the community, though they work on group projects and write group reports. Lectures and skills demonstrations were the main instruction methods. Assessment involved mainly continuous assessment, oral or written reports and summative examination.</p> <p>Conclusion</p> <p>This assessment identified deficiencies in the design and implementation of CBE at several health professional training institutions, with major flaws identified in curriculum content, supervision of trainees, inappropriate assessment, trainee welfare, and underutilization of opportunities for contextual and collaborative learning. Since CBE showed potential to benefit the trainees, community and institutions, we propose a model that delivers a minimum package of CBE and overcomes the wide variation in the concept, conduct and implementation of CBE.</p

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente