Search

We present a numerical scheme for computation of Artificial Neural Networks (ANN) weights, which stems from the Universal Approximation Theorem, avoiding costly iterations. The proposed algorithm adheres to the underlying theory, is highly fast, and results in remarkably low errors when applied to regression and classification problems of complex data sets with x ∈ R n (e.g. Griewank, Gomez-Levy, Shekel, and Polynomial functions) with random noise addition (i.e. Uniform, Normal, Generalized Pareto, Log-Normal, and a mixture of Log-Normal, Exponential, and Frechet), as well as the database for handwritten digits recognition MNIST (Modified National Institute of Standards and Technology) with 7 × 10 4 images. The same mathematical formulation was found capable of approximating highly nonlinear functions in multiple dimensions, with low errors (e.g. 10 - 10 ) for the test set of the unknown functions, their higher-order partial derivatives, as well as numerically solving Partial Differential Equations, such as those appearing in Physics, Engineering, Environmental Sciences, etc. The method is based on the calculation of the weights of each neuron in small neighbourhoods of the data. Accordingly, optimization of hyperparameters is not necessary, as the number of neurons stems directly from the dimensionality of the data, further improving the algorithmic speed. Under this setting, overfitting is inherently avoided, and the results are interpretable and reproducible. The complexity of the proposed algorithm is of class P with O (m N n i cl + N m n 2 + N n 3 + m N 2 + N 3) computing time, with respect to the observations m, features n, and Neurons N, contrary to the NP-Complete class of standard algorithms for ANN training. The performance of the method is high, irrespective of the size of the data set, and the test set errors are similar or smaller than the training errors, indicating the generalization efficiency of the algorithm. A supplementary computer code in Julia and Python Languages is provided, which can be used to reproduce the validation examples, and/or apply the algorithm to other data sets. [ABSTRACT FROM AUTHOR]

Objective: Studies have reported an inverse association between a diet rich in fruits and vegetables and type 2 diabetes (T2D), but data on high-risk ethnic minority groups is limited. We investigated whether serum carotenoids, as biomarkers for fruit and vegetable intake, mediate ethnic differences in the prevalence of T2D.Design: Age-adjusted serum carotenoid concentrations were compared using ANCOVA. A cross-sectional analysis was performed using Cox regression to estimate prevalence ratios (PR) and their 95 % CI of the association between serum carotenoid concentrations and T2D. To study whether serum carotenoids potentially mediate the differences in the prevalence of T2D across ethnic groups, we compared PR of the model including known risk factors and the model additionally adjusted for serum carotenoid concentrations using the Dutch group as reference.Setting: A study among six ethnic groups living in Amsterdam, the Netherlands.Participants: Data on 204 Dutch, 203 South Asian Surinamese, 204 African Surinamese, 203 Turkish and 200 Moroccan-origin participants from the Healthy Life in an Urban Setting (HELIUS) study were used.Results: Serum carotenoid concentrations differed across ethnic groups. After adjusting for confounders, the serum concentrations of total carotenoids (PR 0·67, 95 % CI 0·54, 0·84), α-carotene (PR 0·57, 95 % CI 0·42, 0·77), β-carotene (PR 0·45, 95 % CI 0·32, 0·63) and β-cryptoxanthin (PR 0·73, 95 % CI 0·58, 0·92) were inversely associated with T2D. Despite the associations, serum carotenoids did not mediate the ethnic differences in the prevalence of T2D.Conclusions: The limited contribution of serum carotenoids to ethnic differences in T2D suggests that a focus on increasing fruit and vegetable intake alone will not likely eliminate ethnic differences in T2D prevalence. [ABSTRACT FROM AUTHOR]

Background/objectives: To investigate the association of dietary patterns derived by reduced rank regression (RRR) with depressive symptoms in a multi-ethnic population.Subjects/methods: Cross-sectional data from the HELIUS study were used. In total, 4967 men and women (18-70 years) of Dutch, South-Asian Surinamese, African Surinamese, Turkish and Moroccan origin living in the Netherlands were included. Diet was measured using ethnic-specific food frequency questionnaires. Depressive symptoms were measured with the nine-item patient health questionnaire.Results: By performing RRR in the whole population and per ethnic group, comparable dietary patterns were identified and therefore the dietary pattern for the whole population was used for subsequent analyses. We identified a dietary pattern that was strongly related to eicosapentaenoic acid+docosahexaenoic acid, folate, magnesium and zinc (response variables) and which was characterized by milk products, cheese, whole grains, vegetables, legumes, nuts, potatoes and red meat. After adjustment for confounders, a statistically significant inverse association was observed in the whole population (B: -0.03, 95% CI: -0.06, -0.00, P=0.046) and among Moroccan (B: -0.09, 95% CI: -0.13, -0.04, P=0.027) and South-Asian Surinamese participants (B: -0.05, 95% CI: -0.09, -0.01, P=<0.001), whereas no statistically significant association was found in the remaining ethnic groups. No statistically significant associations were found between the dietary pattern and significant depressed mood in any of the ethnic groups.Conclusions: No consistent evidence was found that consumption of a dietary pattern, high in nutrients that are hypothesized to protect against depression, was associated with lower depressive symptoms across different ethnic groups. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the reliability and validity of the SQUASH physical activity (PA) questionnaire in a multi-ethnic population living in the Netherlands. Methods: We included participants from the HELIUS study, a population-based cohort study. In this study we included Dutch (n = 114), Turkish (n = 88), Moroccan (n = 74), South-Asian Surinamese (n = 98) and African Surinamese (n = 91) adults, aged 18–70 years. The SQUASH was self-administered twice to assess test-re-test reliability (mean interval 6–7 weeks) and participants wore an accelerometer and heart rate monitor (Actiheart) to enable assessment of construct validity. Results: We observed low test-re-test reliability; Intra class correlation coefficients ranged from low (0.05 for moderate/high intensity PA in African Surinamese women) to acceptable (0.78 for light intensity PA in Moroccan women). The discrepancy between self-reported and measured PA differed on the basis of the intensity of activity: self-reported light intensity PA was lower than measured but self-reported moderate/high intensity PA was higher than measured, with wide limits of agreement. The discrepancy between questionnaire and Actiheart measures of moderate intensity PA did not differ between ethnic minority and Dutch participants with correction for relevant confounders. Additionally, the SQUASH overestimated the number of participants meeting the Dutch PA norm; Cohen’s kappas for the agreement were poor, the highest being 0.30 in Dutch women. Conclusion: We found considerable variation in the test-re-test reliability and validity of self-reported PA with no consistency based on ethnic origin. Our findings imply that the SQUASH does not provide a valid basis for comparison of PA between ethnic groups. [ABSTRACT FROM AUTHOR]

This study presents an experimental methodology for the uniaxial stress-strain characterization of urethane and polyvinyl-alcohol (PVA) samples, and compares elicited results with an image-based methodology, simulations, and theory. Elicited results at 40% strain yield error differences between the experimentally measured and the simulated strain of −10 and −20% for the urethane and PVA samples, respectively. The corresponding stress differences were −22 and 11%. Experimental stress-strain responses were fitted using a piecewise linear model (urethane) and using a two-parameter Ogden constitutive model (PVA), based on the over-parameterization criterion. This work directly compares experimental and computational methodologies for the characterization of bio-materials and quantifies the elicited errors. [ABSTRACT FROM AUTHOR]

Objectives:Ethnic minorities are often not included in studies of diet and health because of a lack of validated instruments to assess their habitual diets. Given the increased ethnic diversity in many high-income countries, insight into the diets of ethnic minorities is needed for the development of nutritional policies and interventions. In this paper, we describe the development of ethnic-specific food frequency questionnaires (FFQs) to study the diets of Surinamese (African and South Asian), Turkish, Moroccan and ethnic Dutch residents of The Netherlands.Methods:An existing Dutch FFQ was adapted and formed the basis for three new FFQs. Information on food intake was obtained from single 24 h recalls. Food items were selected according to their percentage contribution to and variance in absolute nutrient intake of the respective ethnic groups. A nutrient database for each FFQ was constructed, consisting of data from the Dutch Food Composition table; data on ethnic foods were based on new chemical analyses and available international data.Results:We developed four ethnic-specific FFQs using a standardised approach that included ~200 food items each and that covered more than 90% of the intake of the main nutrients of interest.Conclusions:The developed FFQs will enable standardised and comparable assessment of the diet of five different ethnic groups and provide insight into the role of diet in differences in health between ethnic groups. The methodology described in this paper and the choices made during the development phase may be useful in developing similar FFQs in other settings. [ABSTRACT FROM AUTHOR]

Background:Ethnic minority groups in Western European countries tend to have higher levels of overweight than the majority populations for reasons that are poorly understood. Investigating relative differences between countries could enable an investigation of the importance of national context in determining these inequalities.Objective:To explore: (1) whether Indian and African origin populations in England and the Netherlands are similarly disadvantaged compared with the White populations in terms of the prevalence of overweight and central obesity; (2) whether the previously known Dutch advantage of relatively low overweight prevalence is also observed in Dutch ethnic minority groups and (3) the contribution of health behaviour and socio-economic position to the differences observed.Methods:Secondary analyses of population-based studies of 16 406 participants from England and the Netherlands. Prevalence ratios were estimated using regression models.Results:Except for African men, ethnic minority groups in both countries had higher rates of overweight and central obesity than their White counterparts. However, the Dutch minority groups were relatively more disadvantaged than English minority groups as compared with the majority populations. The Dutch advantage of the low prevalence of obesity was only seen in White men and women and African men. In contrast, English-Indian (prevalence ratio=0.87, 95% confidence interval (CI): 0.81-0.93) and English-Caribbean (prevalence ratio=0.82, 95% CI: 0.76-0.89) women were less centrally obese than their Dutch equivalents. The Dutch-Indian men were very similar to the English-Indian men. The contribution of health behaviour and socio-economic position to the observed differences were small.Conclusion:Contrary to the patterns in White groups, the Dutch ethnic minority women were more obese than their English equivalents. More work is needed to identify factors that may contribute to these observed differences. [ABSTRACT FROM AUTHOR]

The joint use of opportunistic scheduling and orthogonal frequency division multiple access (OFDMA) provide significant gains in environments of low mobility and scatter for which channel variations are low. The downside of opportunistic scheduling in multicarrier systems such as OFDMA, lies in the substantial uplink overhead required to feed back by the mobile stations (MSs) describing users' instantaneous link conditions. This study presents a novel approach towards multicarrier opportunistic scheduling for a multi-input multi-output configuration that promises major overhead reductions with only minor degradations on downlink throughput performance. The conventional channel quality indicator, in the form of instantaneous signal-to-noise ratio (SNR) is replaced by an alternative metric, in the form of the strongest cluster indices of each MS, which imposes a significantly reduced overhead. This study examines the performance of the proposes metric for random beamforming and examines the benefits in terms of throughput and feedback overhead over existing schemes. The results show that the proposed scheduling approach maintains performance within 1 dB of a full SNR based feedback scheme, while achieving feedback overhead reduction up to a factor of 24 and also providing improved fairness among users experiencing different channel gain levels. [ABSTRACT FROM AUTHOR]

Background: Recreational drug use in common, particularly in those attending nightclubs. Their knowledge about the potential toxicity of drugs and how to manage this is variable. Methods: We therefore established a multidisciplinary local network of key stakeholders interested in the prevention and management of recreational drug toxicity. Through this network we designed a unique outreach educational concept, 'Drug Idle', for recreational drug users and their friends. This was run within nightclub environments in a user-friendly, non-judgemental forum. We describe here the development of this educational concept and how it was evaluated and adapted on the basis of feedback from attendees. Results: 149 attended the three Drug Idle events as part of this study. All of those trialling the finalized concept thought all three components of the concept were useful, 96.0% that it was of appropriate duration and 98.8% that they would recommend future events to a friend. Conclusions: We believe that wider use of this outreach educational concept will help to improve the knowledge of those using recreational drugs, especially concerning management of drug toxicity. Additionally, it will provide them with information that will enable them to make informed decisions about the risk of continuing use of recreational drugs. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To assess early outcomes in the elderly population undergoing coronary revascularisation with and without cardiopulmonary bypass (CPB). METHODS: Meta-analysis of all retrospective, non-randomised studies comparing off-pump coronary artery bypass (OPCAB) versus CPB techniques in the elderly (> 70 years) between 1999 and 2005. Age-related early outcomes of interest were death, stroke, atrial fibrillation (AF), renal failure and length of stay in hospital. The random effects model was used. Sensitivity and heterogeneity were analysed. RESULTS: Analysis of 14 non-randomised studies comprising 4921 patients (OPCAB, 1533 (31.1%) and CPB, 3388 (68.9%)) showed a significantly lower incidence of death in the OPCAB group (odds ratio (OR) 0.48, 95% CI 0.28 to 0.84). This effect was greater in OPCAB octogenarians (OR 0.26, 95% CI 0.12 to 0.57). The pattern of incidence of stroke among the OPCAB octogenarians (OR 0.19, 95% CI 0.07 to 0.56) was similar. The incidence of AF was lower in the OPCAB group (OR 0.77, 95% CI 0.61 to 0.97). The incidence of renal failure did not differ. Length of hospital stay was shorter in the OPCAB group, although with significant heterogeneity. CONCLUSIONS: OPCAB may be associated with lower incidence of death, stroke and AF in the elderly, which may result in shorter length of hospital stay. A large randomised trial would confirm whether the elderly would benefit more from OPCAB surgery. [ABSTRACT FROM AUTHOR]

Objective: To assess early outcomes in the elderly population undergoing coronary revascularisation with and without cardiopulmonary bypass (CPB). Methods: Meta-analysis of all retrospective, non-randomised studies comparing off-pump coronary artery bypass (OPCAB) versus CPB techniques in the elderly (> 70 years) between 1999 and 2005. Age-related early outcomes of interest were death, stroke, atrial fibrillation (AF), renal failure and length of stay in hospital. The random effects model was used. Sensitivity and heterogeneity were analysed. Results: Analysis of 14 non-randomised studies comprising 4921 patients (OPCAB, 1533 (31.1%) and CPB, 3388 (68.9%)) showed a significantly lower incidence of death in the OPCAB group (odds ratio (OR) 0.48, 95% CI 0.28 to 0.84). This effect was greater in OPCAB octogenarians (OR 0.26, 95% CI 0.12 to 0.57). The pattern of incidence of stroke among the OPCAB octogenarians (OR 0.19, 95% CI 0.07 to 0.56) was similar. The incidence of AF was lower in the OPCAB group (OR 0.77, 95% CI 0.61 to 0.97). The incidence of renal failure did not differ. Length of hospital stay was shorter in the OPCAB group, although with significant heterogeneity. Conclusions: OPCAB may be associated with lower incidence of death, stroke and AF in the elderly, which may result in shorter length of hospital stay. A large randomised trial would confirm whether the elderly would benefit more from OPCAB surgery. [ABSTRACT FROM AUTHOR]

Background To consider the changes in overall diet quality following migration we examined the associations of acculturation variables and education level with diet in Surinamese South Asian and Surinamese Afro-Caribbean origin on the one hand, and ethnic Dutch residents of the Netherlands on the other. Surinam is a former Dutch colony in South America. Methods We randomly selected men and women aged 35-60 years: ethnic Dutch, n = 552; South Asian, n = 306; Afro-Caribbean, n = 660. Intakes of fruit, vegetables, red meat, fish, vegetable oils, breakfast and salt were measured using a short questionnaire that formed the basis for a 'diet quality indicator' score. Highest education was measured and acculturation of the Surinamese groups was assessed by age at migration, number of resident years and a scale measure of social contacts with ethnic Dutch. Results Compared with ethnic Dutch, both Surinamese groups scored higher on overall diet quality (P

Background: The role of laparoscopic surgery for patients with ileocecal Crohn's disease is a contentious issue. This metaanalysis aimed to compare open resection with laparoscopically assisted resection for ileocecal Crohn's disease.Methods: A literature search of the Medline, Ovid, Embase, and Cochrane databases was performed to identify comparative studies reporting outcomes for both laparoscopic and open ileocecal resection. Metaanalytical techniques were applied to identify differences in outcomes between the two groups. Sensitivity analysis was undertaken to evaluate the heterogeneity of the study.Results: Of 20 studies identified by literature review, 15 satisfied the criteria for inclusion in the study. These included outcomes for 783 patients, 338 (43.2%) of whom had undergone laparoscopic resection, with an overall conversion rate to open surgery of 6.8%. The operative time was significantly longer in the laparoscopic group, by 29.6 min (p = 0.002), although the blood loss and complications in the two groups were similar. In terms of postoperative recovery, the laparoscopic patients had a significantly shorter time for recovery of their enteric function and a shorter hospital stay, by 2.7 days (p < 0.001).Conclusions: For selected patients with noncomplicated ileocecal Crohn's disease, laparoscopic resection offered substantial advantages in terms of more rapid resolution of postoperative ileus and shortened hospital stay. There was no increase in complications, as compared with open surgery. The contraindications to laparoscopic approaches for Crohn's disease remain undefined. [ABSTRACT FROM AUTHOR]

We have analyzed the 5'-upstream promoter region of the presenilin 2 gene (PSEN2) for regulatory elements and examined Alzheimer disease (AD) patients and non-demented individuals for polymorphisms in the 5' upstream promoter region of the PSEN2 gene. Direct sequencing analysis detected a common single adenine (A) nucleotide deletion polymorphism in the upstream promoter region of the PSEN2 gene. Examination of cohorts of AD patients and agematched control individuals revealed no statistically significant differences in the frequency of this polymorphism when compared with the total sample of AD patients and control individuals. However, subgroup and regression analysis suggested that the relatively rare -A/-A genotype increases risk of AD among subjects lacking apolipoprotein E (APOE) ε4 and among persons ages 65 years and younger. DNA sequence and DNA-protein binding analysis demonstrated that this mutation negates binding with putative repressor transcription factor (TF), interferon regulatory factor 2 (IRF2), in nuclear extracts prepared from the aged human brain neocortex. However this mutation creates a potential regulatory element, C/EBPbeta, that is responsive to pro-inflammatory (PI) induction. The expression activity assay with luciferase reporter gene into normal human neural progenitor ceils in primary culture shows that the mutant PSEN2 regulatory region exhibits a 1.8-fold higher level of basal expression and is sensitive to IL-1β` and Aβ42, but that it is synergistically induced 3.2-fold over the wild-type PSEN2 by [IL-1β+Aβ42]. These results suggest that under PI and oxygen stress conditions relatively minor variations in PSEN2 promoter DNA sequence structure can enhance PSEN2 gene expression and that consequently these may play a role in the induction and/or proliferation of a PI response in AD brain. [ABSTRACT FROM AUTHOR]

Chronic stress increases chronic disease risk and may underlie the association between adverse socioeconomic conditions and adverse health outcomes. The relationship between such conditions and chronic stress is complex due to feedback loops between stressor exposure and psychological processes, encompassing different temporal (acute stress response to repeated exposure over the life course) and spatial (biological/ psychological/social) scales. We examined this relationship from a complexity science perspective. We developed a causal loop diagram to interpret available evidence. Literature evidence was used to confirm/contest the variables and causal links included in the conceptual framework and refine their conceptualisation. Our findings were evaluated by 8 independent researchers. Adverse socioeconomic conditions imply an accumulation of stressors and increase the likelihood of exposure to uncontrollable childhood and life course stressors. Repetition of such stressors may activate mechanisms that can affect coping resources and coping strategies and stimulate appraisal of subsequent stressors as uncontrollable. We identified 5 feedback loops describing these mechanisms: progressive deterioration of access to coping resources because of repeated insolvability of stressors; perception of stressors as uncontrollable due to learned helplessness; tax on cognitive bandwidth caused by stress; stimulation of problem avoidance to provide relief from the stress response and free up cognitive bandwidth; susceptibility to appraising stimuli as stressors against a background of stress. The complexity science perspective revealed that adverse socioeconomic conditions imply recurrent stressor exposure which impacts chronic stress via amplifying feedback loops that together could be conceptualised as one vicious cycle. Therefore, in order for individual-level psychological interventions to be effective, the context of adverse socioeconomic conditions also needs to be addressed. [ABSTRACT FROM AUTHOR]

Objectives: We report a rare case of burns following the use of automated air-fresheners. Methods: We present a case report with a brief overview of the literature relating to burns associated with air-fresheners. The mechanism and treatment of these types of injuries are also described. Results: A 44 year-old female was admitted under the care of the burns team following burns secondary to an exploding air-freshener canister. The patient sustained burns to the face, thorax and arms resulting in a seven-day hospital admission. The burns were treated conservatively. Conclusions: To our knowledge this is one of the few documented cases of burns as a result of air-fresheners. As they become more ubiquitous, we anticipate the incidence of such cases to increase. As such, they pose a potential public health concern on a massive scale. [ABSTRACT FROM AUTHOR]

Neck and anterior chest wall flushing can be a social handicap to the sufferer and current treatment options are often unsatisfactory. We report the case of a 48-year-old woman with severe flushing of the anterior neck and anterior chest wall which resolved after three treatments of intracutaneous botulinum toxin A injections. We believe that this treatment method for skin flushing is simple, effective and free of significant side effects at these sites. Further studies are needed to evaluate the duration of the therapeutic effect. [ABSTRACT FROM AUTHOR]

We report the first case of spontaneous rupture of a true uterine artery aneurysm in a 69-year-old woman presenting with severe abdominal pain, a left iliac fossa mass, anaemia and a retroperitoneal haematoma on CT scanning. In this patient, the aneurysm was successfully embolised using microcoils. The different imaging modalities used for diagnosis and the treatment options are discussed. [ABSTRACT FROM AUTHOR]

The article presents two medical cases involving body packers, who try to smuggle narcotics by an intracorporeal route. A 33-year-old man, just off a flight from the West Indies, was referred to Customs when he started vomiting and complaining of lower abdominal pain. A laparotomy was used to remove the packages of cocaine. A 38-year-old man had a swollen scrotum and a strangulated right inguinal hernia.

Describes a case of facial hyperhidrosis in a 29-year-old man. Effect of thoracoscopic sympathectomy; Starch-iodine preparation prior to the procedure; Iatrogenic variation of the harlequin syndrome.

A small industrial effluent treatment plant has been designed and installed for the treatment of wastewater from a potato chips and snacks factory. The total daily flow rate to the plant was 115 m3/d, while the influent COD mass flux was 838.7 kg/d and the BOD mass flux was 626.7 kg/d. The applied method of treatment is a simple upflow anaerobic reactor with internal settling and gas collection units, followed by aerobic treatment based on the activated sludge process with diffused air system. The quality of the treated water is better than requested and the overall treatment process efficiencies are 99.2% for COD removal and 99.5% for BOD5 removal. The results of the operation of the plant during the first five months are examined and described in this paper. [ABSTRACT FROM AUTHOR]