•Automatic extraction of users’ groups based on hierarchical clustering.•Can be applied prior to any recommender algorithm.•Targets sparsity and high dimensionality in recommender systems.•Ensures a ...minimum number of users in each cluster for better accuracy.•Techniques don’t require critical parameters.
Recommender Systems (RS) support users to find relevant contents, such as movies, books, songs, and other products based on their preferences. Such preferences are gathered by analyzing past users’ interactions, however, data collected for this purpose are typically prone to sparsity and high dimensionality. Clustering-based techniques have been proposed to handle those problems effectively and efficiently by segmenting the data into a number of similar groups based on predefined characteristics. Although such techniques have gained increasing attention in the recommender systems community, they are usually bound to a particular recommender system and/or require critical parameters, such as the number of clusters. In this paper, we present three variants of a general-purpose method to optimally extract users’ groups from a hierarchical clustering algorithm, specifically targeting RS problems. The proposed extraction methods do not require critical parameters and enable any recommender algorithm to be used at the recommendation step. Our experiments have shown promising recommendation results in the context of nine well-known public datasets from different domains.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Body mass index (BMI) and mortality in old adults from the general population have been related in a U‐shaped or J‐shaped curve. However, limited information is available for elderly nursing home ...populations, particularly about specific cause of death. A systematic PubMed/EMBASE/CINAHL/SCOPUS search until 31 May 2014 without language restrictions was conducted. As no published study reported mortality in standard BMI groups (<18.5, 18.5–24.9, 25–29.9, ≥30 kg/m²), the most adjusted hazard ratios (HRs) according to a pre‐defined list of covariates were obtained from authors and pooled by random‐effect model across each BMI category. Out of 342 hits, 20 studies including 19,538 older nursing home residents with 5,223 deaths during a median of 2 years of follow‐up were meta‐analysed. Compared with normal weight, all‐cause mortality HRs were 1.41 (95% CI = 1.26–1.58) for underweight, 0.85 (95% CI = 0.73–0.99) for overweight and 0.74 (95% CI = 0.57–0.96) for obesity. Underweight was a risk factor for higher mortality caused by infections (HR = 1.65 95% CI = 1.13–2.40). RR results corroborated primary HR results, with additionally lower infection‐related mortality in overweight and obese than in normal‐weight individuals. Like in the general population, underweight is a risk factor for mortality in old nursing home residents. However, uniquely, not only overweight but also obesity is protective, which has relevant nutritional goal implications in this population/setting.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Stent infection is extremely rare, especially in stents placed in the internal carotid artery (ICA). Treatment in these cases remains controversial and no consensus has been reached, resulting in ...high mortality in all cases. We report the case of a 78-year-old man undergoing stent placement in the left ICA who, 20 days later, presented with infection at the stent site and a large pseudoaneurysm. The primary infectious focus was the teeth. The patient was treated with antibiotics and placement of a Casper stent, a dual layer braided metal stent with micro-mesh, intended to determine flow diversion and arterial wall reconstruction. Although the procedure was able to reduce the pseudoaneurysm, the patient eventually died of sepsis. We believe that the use of dual layer stents, with a flow-diverting effect, may be a treatment option in selected cases. However, further studies are needed to confirm this hypothesis.
Aldosterone promotes non-genomic effects in endothelial and vascular smooth muscle cells via activation of mineralocorticoid receptors (MR) and G protein-coupled estrogen receptors (GPER). GPER ...activation is associated with beneficial/protective effects in the vasculature. Considering that vascular dysfunction plays a major role in diabetes-associated complications, we hypothesized that the beneficial effects mediated by vascular GPER activation, in response to aldosterone, are decreased in diabetes. Mesenteric resistance arteries from female, 14-16 weeks-old, control and diabetic (db/db) mice were used. Phenylephrine (PhE)-induced contractions were greater in arteries from db/db vs. control mice. Aldosterone (10 nM) increased maximal contractile responses to PhE in arteries from control mice, an effect elicited via activation of GPER. Although aldosterone did not increase PhE responses in arteries from db/db mice, blockade of GPER, and MR decreased PhE-induced contractile responses in db/db mesenteric arteries. Aldosterone also reduced the potency of acetylcholine (ACh)-induced relaxation in arteries from both control and db/db mice via MR-dependent mechanisms. GPER antagonism further decreased ACh-induced relaxation in the control group, but did not affect ACh responses in the diabetic group. Aldosterone increased extracellular signal-regulated kinase 1/2 phosphorylation in arteries from control and db/db mice by a GPER-dependent mechanism. GPER, but not MR, gene, and protein expression, determined by RT-PCR and immunoblotting/immunofluorescence assays, respectively, were increased in arteries from db/db mice vs. control arteries. These findings indicate that aldosterone activates both vascular MR and GPER and that the beneficial effects of GPER activation are decreased in arteries from diabetic animals. Our results further elucidate the mechanisms by which aldosterone influences vascular function and contributes to vascular dysfunction in diabetes. Financial Support: FAPESP, CNPq, and CAPES, Brazil.
Performing Multiple-Input Multiple-Output (MIMO) tests to reproduce the vibration environment in a user-defined number of control points of a unit under test is necessary in applications where a ...realistic environment replication has to be achieved. MIMO tests require vibration control strategies to calculate the required drive signal vector that gives an acceptable replication of the target. This target is a (complex) vector with magnitude and phase information at the control points for MIMO Sine Control tests while in MIMO Random Control tests, in the most general case, the target is a complete spectral density matrix. The idea behind this work is to tailor a MIMO random vibration control approach that can be generalized to other MIMO tests, e.g. MIMO Sine and MIMO Time Waveform Replication. In this work the approach is to use gradient-based procedures over the complex space, applying the so called CR-Calculus and the adaptive array theory. With this approach it is possible to better control the process performances allowing the step-by-step Jacobian Matrix update. The theoretical bases behind the work are followed by an application of the developed method to a two-exciter two-axis system and by performance comparisons with standard methods.
The aim of this paper is to investigate whether bioelectrical impedance vector analysis (BIVA) can be a suitable technique for the assessment of sarcopenia. We also investigate the potential use of ...specific BIVA as an indicator of sarcopenic obesity.
The sample comprised 207 free-living elderly individuals of both sexes, aged 65 to 93 years. Anthropometric and bioelectrical measurements were taken according to standard criteria. The "classic" and "specific" BIVA procedures, which respectively correct bioelectrical values for body height and body geometry, were used. Dual energy X-ray absorptiometry (DXA) was used as the reference method for identifying sarcopenic and obese sarcopenic individuals. Bioelectrical and DXA values were compared using Student's t-test and Hotelling's T(2) test, as well as Pearson's correlation coefficient.
According to classic BIVA, sarcopenic individuals of both sexes showed higher values of resistance/height (R/H; p < 0.01) and impedance/height (Z/H; p < 0.01), and a lower phase angle (p < 0.01). Similarly, specific BIVA showed significant differences between sarcopenic and nonsarcopenic individuals (men: T(2) = 15.7, p < 0.01; women: T(2) = 10.7, p < 0.01), with the sarcopenic groups showing a lower specific reactance and phase angle. Phase angle was positively correlated with the skeletal muscle mass index (men: r = 0.52, p < 0.01; women: r = 0.31, p < 0.01). Specific BIVA also recognized bioelectrical differences between sarcopenic and sarcopenic obese men (T(2) = 13.4, p < 0.01), mainly due to the higher values of specific R in sarcopenic obese individuals.
BIVA detected muscle-mass variations in sarcopenic individuals, and specific BIVA was able to discriminate sarcopenic individuals from sarcopenic obese individuals. These procedures are promising tools for screening for presarcopenia, sarcopenia, and sarcopenic obesity in routine practice.
Modern wind turbine blades are being tested for certification purposes in accordance to the IEC-64100 standard. Part 23 of the norm details the requirements for the full scale structural testing of ...rotor blades. As a minimum, it requires measurement of the first and second flap wise and first edge wise natural frequencies. It lists damping and mode shapes as other blade properties which may be of interest and optionally measured. The paper presents the modal model parameters estimation based on the experimental modal analysis. In two tests performed, the input force has been introduced through impact hammer and two electrodynamic shakers excitation. Several first modes had been identified for both excitation methods, including first torsional mode of the investigated blade. Results of the modal tests can be used to (a) provide more detailed information about the structural dynamics characteristics of the blade and (b) improve the design by adjusting the dynamic properties of the blade to some desired condition.
OBJECTIVES: This study aimed to ascertain the efficacy of bioelectrical impedance vector analysis (BIVA) in assessing body composition in the elderly by comparing findings with the results of ...dual-energy X-ray absorptiometry (DXA), and to test an analytical variant of the method (specific BIVA). DESIGN: Cross-sectional study. PARTICIPANTS: The sample comprised 207 free-living elderly individuals (75 men and 132 women) aged 65 to 93 years. MEASUREMENTS: Anthropometric and bioelectrical measurements were taken according to standard criteria. BIVA was applied using the ‘classic’ procedure and correcting bioelectrical values for body geometry to obtain an estimate of the whole-body impedivity. DXA was used as a reference body composition assessment method. BIVA (classic and specific values) and DXA findings were compared using Student’s t and Hotelling’s T2 tests, and Pearson’s correlation coefficient. RESULTS: In both sexes, BIVA distinguished between individuals with different amounts of fat and fat-free mass (lean mass including bone mineral content), according to DXA, but not between those with different proportions of fat mass (FM%). Specific bioelectrical values detected changes in body composition. CONCLUSION: BIVA should be used with caution for evaluating body composition in the elderly. Specific bioelectrical values proved effective, showing promise as a methodological variant of BIVA, suitable for identifying age-related changes in body fatness.
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EMUNI, GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UL, UM, UPCLJ, UPUK, VSZLJ, ZAGLJ, ZRSKP
Nonalcoholic fatty liver disease (NAFLD) is associated with all the components of metabolic syndrome (MS) and might to be considered an additional component of MS itself. The Italian Society for the ...Study of Atherosclerosis (SISA) in 2005 started a research project aimed to study the NAFLD, using ultrasound (US), in nondiabetic MS subjects matching at least one of the ATP III criteria for HDL-C or triglycerides TG. Prevalence of US-NAFLD and its associated risk factors and prevalence of hypertransaminasemia and its possible determinants were evaluated. NAFLD prevalence was 0.78. Men with steatosis compared to men without steatosis were younger (
P
< 0.05) with higher TG (
P
< 0.03), homeostasis model assessment insulin resistance (HOMA-R) (
P
< 0.003), and visceral fat thickness (VFT) (
P
< 0.0001). Women with steatosis showed higher TG (
P
< 0.05), HOMA-R (
P
< 0.04), VFT (
P
< 0.0001), and lower age (
P
< 0.05). At multivariate analyses, VFT (
P
< 0.0001), HOMA-R (
P
< 0.02), and TG/HDL (
P
< 0.05) were associated with severity of NAFLD. Age (
P
< 0.05), LogTG (
P
< 0.005), and VFT (
P
< 0.01) were associated with higher ALT. The US prevalence of steatosis in this study (0.78) is the highest reported in patients with MS. Considering the exclusion of severe obese and diabetic patients and the recruitment criteria, this finding highlights the prominent role played by the alterations of lipid metabolism in the pathogenesis of NAFLD.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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