The eigenspectra of Indian musical drums

In a family of drums used in the Indian subcontinent, the circular drum head is made of material of non-uniform density. Remarkably, and in contrast to a circular membrane of uniform density, the low eigenmodes of the non-uniform membrane are harmonic. In this work we model the drum head by a non-uniform membrane whose density varies smoothly between two prescribed values. Using a Fourier-Chebyshev spectral collocation method we obtain the eigenmodes and eigenvalues of the drum head. For a suitable choice of parameters, which we find by optimising a cost function, the eigenspectra obtained from our model are in excellent agreement with experimental values. Our model and the numerical method should find application in numerical sound synthesis

Synchronization of Sound Sources

Sound generation and -interaction is highly complex, nonlinear and self-organized. Already 150 years ago Lord Rayleigh raised the following problem: Two nearby organ pipes of different fundamental frequencies sound together almost inaudibly with identical pitch. This effect is now understood qualitatively by modern synchronization theory (M. Abel et al., J. Acoust. Soc. Am., 119(4), 2006). For a detailed, quantitative investigation, we substituted one pipe by an electric speaker. We observe that even minute driving signals force the pipe to synchronization, thus yielding three decades of synchronization -- the largest range ever measured to our knowledge. Furthermore, a mutual silencing of the pipe is found, which can be explained by self-organized oscillations, of use for novel methods of noise abatement. Finally, we develop a specific nonlinear reconstruction method which yields a perfect quantitative match of experiment and theory.Comment: 5 pages, 4 figure

YKL-40, a Marker of Inflammation and Endothelial Dysfunction, Is Elevated in Patients With Type 1 Diabetes and Increases With Levels of Albuminuria

OBJECTIVE—The inflammation marker YKL-40 is elevated in patients with type 2 diabetes and is associated with atherosclerosis and increased cardiovascular mortality. In the present study, YKL-40 levels were examined in patients with type 1 diabetes with increasing levels of albuminuria, known to be associated with an increased risk of cardiovascular disease

Zicht op de plantaardige biologische keten

This study forms part of the project entitled 'Visions of organic farming: a system analysis'. This project is being financed by Wageningen University and Research Centre, from Strategic Expertise Development funds. This project distinguishes categories of people in order to crystallise the visions. This report comprises a description of the vegetable-based organic chain. This chain is described from the consumer stage right through to the suppliers. The description concludes with a SWOT analysis for the four categories of people and a quantification of the technical parameters for those categories. De studie vormt een onderdeel van het project 'Visies op biologische landbouw: een systeem analyse'. Dit project is gefinancierd door Wageningen Universiteit en Researchcentrum uit middelen voor Strategische Expertise Ontwikkeling. In dit project worden mensbeelden on-derscheiden om de visies te concretiseren. Dit rapport bevat een beschrijving van de plantaardige biologische keten. Deze keten wordt vanaf de consument tot de toeleverende be-drijven beschreven. De beschrijving eindigt met een SWOT-analyse voor de vier mensbeelden en kwantificering van de technische parameters voor die mensbeelden.Crop Production/Industries,

Renal Effects of Aliskiren Compared With and in Combination With Irbesartan in Patients With Type 2 Diabetes, Hypertension, and Albuminuria

Objective: We investigated if the antiproteinuric effect of the direct renin inhibitor aliskiren is comparable to irbesartan, and the effect of the combination. Research Design and Methods: Double-blind, randomized, cross-over trial. After a one-month washout period 26 patients with type 2 diabetes, hypertension and albuminuria (>100mg/day) were randomized to four 2-month treatment periods in random order with placebo, aliskiren 300 mg once daily, irbesartan 300 mg once daily or the combination using identical doses. Patients received furosemide in a stable dose throughout the study. Primary endpoint was change in albuminuria. Secondary measures included change in 24h blood pressure (24h BP) and glomerular filtration rate (GFR). Results: Placebo geometric mean albuminuria was 258 mg/day (range 84-2361), mean 24h BP was 140/73 (SD 15/8) mmHg, GFR was 89 (SD 27) ml/min/1.73 m(2). Aliskiren treatment reduced albuminuria by 48% (95% confidence interval 27-62) compared to placebo (p<0.001), not significantly different from irbesartan treatment (58% (42-70) (p<0.001 vs. placebo)). Combination treatment reduced albuminuria by 71% (59-79), more than either monotherapy (p<0.001 and p=0.028). Fractional clearances of albumin were significantly reduced (46, 56 and 67% reduction vs. placebo). 24h BP was reduced 3/4 mmHg by aliskiren (NS/p=0.009), 12/5 mmHg by irbesartan (p<0.001/p=0.002) and 10/6 mmHg by the combination (p=0.001/p<0.001). GFR was significantly reduced 4.6 (0.3, 8.8) ml/min/1.73m(2) by aliskiren, 8.0 (3.6, 12.3) ml/min/1.73m(2) by irbesartan and 11.7 (7.4, 15.9) ml/min/1.73m(2) by the combination. Conclusions: Combining aliskiren and irbesartan is more antiproteinuric in type 2 diabetic patients with albuminuria as compared to monotherapy

Effect of semaglutide on major adverse cardiovascular events by baseline kidney parameters in participants with type 2 diabetes and at high risk of cardiovascular disease:SUSTAIN 6 and PIONEER 6 post hoc pooled analysis

Background: Semaglutide is a glucose-lowering treatment for type 2 diabetes (T2D) with demonstrated cardiovascular benefits; semaglutide may also have kidney-protective effects. This post hoc analysis investigated the association between major adverse cardiovascular events (MACE) and baseline kidney parameters and whether the effect of semaglutide on MACE risk was impacted by baseline kidney parameters in people with T2D at high cardiovascular risk.Methods: Participants from the SUSTAIN 6 and PIONEER 6 trials, receiving semaglutide or placebo, were categorised according to baseline kidney function (estimated glomerular filtration rate [eGFR] &lt; 45 and ≥ 45–&lt;60 versus ≥ 60 mL/min/1.73 m2) or damage (urine albumin:creatinine ratio [UACR] ≥ 30–≤300 and &gt; 300 versus &lt; 30 mg/g). Relative risk of first MACE by baseline kidney parameters was evaluated using a Cox proportional hazards model. The same model, adjusted with inverse probability weighting, and a quadratic spline regression were applied to evaluate the effect of semaglutide on risk and event rate of first MACE across subgroups. The semaglutide effects on glycated haemoglobin (HbA1c), body weight (BW) and serious adverse events (SAEs) across subgroups were also evaluated.Results: Independently of treatment, participants with reduced kidney function (eGFR ≥ 45–&lt;60 and &lt; 45 mL/min/1.73 m2: hazard ratio [95% confidence interval]; 1.36 [1.04;1.76] and 1.52 [1.15;1.99]) and increased albuminuria (UACR ≥ 30–≤300 and &gt; 300 mg/g: 1.53 [1.14;2.04] and 2.52 [1.84;3.42]) had an increased MACE risk versus those without. Semaglutide consistently reduced MACE risk versus placebo across all eGFR and UACR subgroups (interaction p value [pINT] &gt; 0.05). Semaglutide reduced HbA1c regardless of baseline eGFR and UACR (pINT&gt;0.05); reductions in BW were affected by baseline eGFR (pINT&lt;0.001) but not UACR (pINT&gt;0.05). More participants in the lower eGFR or higher UACR subgroups experienced SAEs versus participants in reference groups; the number of SAEs was similar between semaglutide and placebo arms in each subgroup.Conclusions: MACE risk was greater for participants with kidney impairment or damage than for those without. Semaglutide consistently reduced MACE risk across eGFR and UACR subgroups, indicating that semaglutide provides cardiovascular benefits in people with T2D and at high cardiovascular risk across a broad spectrum of kidney function and damage.Trial registrations: NCT01720446; NCT02692716.</p

Effect of mineralocorticoid receptor antagonists on proteinuria and progression of chronic kidney disease: a systematic review and meta-analysis

Background: Hypertension and proteinuria are critically involved in the progression of chronic kidney disease. Despite treatment with renin angiotensin system inhibition, kidney function declines in many patients. Aldosterone excess is a risk factor for progression of kidney disease. Hyperkalaemia is a concern with the use of mineralocorticoid receptor antagonists. We aimed to determine whether the renal protective benefits of mineralocorticoid antagonists outweigh the risk of hyperkalaemia associated with this treatment in patients with chronic kidney disease. Methods: We conducted a meta-analysis investigating renoprotective effects and risk of hyperkalaemia in trials of mineralocorticoid receptor antagonists in chronic kidney disease. Trials were identified from MEDLINE (1966–2014), EMBASE (1947–2014) and the Cochrane Clinical Trials Database. Unpublished summary data were obtained from investigators. We included randomised controlled trials, and the first period of randomised cross over trials lasting ≥4 weeks in adults. Results: Nineteen trials (21 study groups, 1 646 patients) were included. In random effects meta-analysis, addition of mineralocorticoid receptor antagonists to renin angiotensin system inhibition resulted in a reduction from baseline in systolic blood pressure (−5.7 [−9.0, −2.3] mmHg), diastolic blood pressure (−1.7 [−3.4, −0.1] mmHg) and glomerular filtration rate (−3.2 [−5.4, −1.0] mL/min/1.73 m2). Mineralocorticoid receptor antagonism reduced weighted mean protein/albumin excretion by 38.7 % but with a threefold higher relative risk of withdrawing from the trial due to hyperkalaemia (3.21, [1.19, 8.71]). Death, cardiovascular events and hard renal end points were not reported in sufficient numbers to analyse. Conclusions: Mineralocorticoid receptor antagonism reduces blood pressure and urinary protein/albumin excretion with a quantifiable risk of hyperkalaemia above predefined study upper limit