1,644 research outputs found
Spatial variation in biodiversity, soil degradation and productivity in agricultural landscapes in the highlands of Tigray, northern Ethiopia
There is a growing concern about food security and sustainability of agricultural production in developing countries. However, there are limited attempts to quantify agro-biodiversity losses and relate these losses to soil degradation and crop productivity, particularly in Tigray, Ethiopia. In this study, spatial variation in agro-biodiversity and soil degradation was assessed in 2000 and 2005 at 151 farms in relation to farm, productivity, wealth, social, developmental and topographic characteristics in Tigray, northern Ethiopia. A significant decrease in agro-biodiversity was documented between 2000 and 2005, mainly associated with inorganic fertilizer use, number of credit sources and proximity to towns and major roads. Agro-biodiversity was higher at farms with higher soil fertility (available P and total N) and higher productivity (total caloric crop yield). Low soil organic matter, few crop selection criteria and steep slopes contributed to soil erosion. Sparsely and intensively cultivated land use types, as determined from satellite images, were associated with high and low agro-biodiversity classes, respectively, as determined during on-farm surveys in 2005. This study gives insight into the recent changes in and current status of agro-biodiversity and soil degradation at different spatial scales, which can help to improve food security through the maintenance of agro-biodiversity resource
A prospective cohort study in patients with type 2 diabetes mellitus for validation of biomarkers (PROVALID) –study design and baseline characteristics
Background/Aims: The prevalence of diabetes mellitus type 2 and kidney disease in these
patients varies widely between European countries. Methods: In addition to store biosamples
the “Prospective cohort study in patients with type 2 diabetes mellitus for validation
of biomarkers” collects information on history, physical status, laboratory measurements
and medication in 4000 patients with diabetes mellitus type 2, being taken care of at the
primary level of healthcare in 5 European countries (Austria, Hungary, Netherlands, Poland
and Scotland). Next to comparing the rate of loss of eGFR between the countries, a further
objective of the PROVALID study is to determine the 5-year cumulative incidence of renal and
cardiovascular outcomes. Results: The mean age of the population recruited is 62.9±10 years,
54.6% are male and the mean BMI is 30.9±5.4 kg/m2
. Metabolic control (median HBA1c 6.8
% (6.2;7.5)) is achieved via administration of metformin in 67.4% of the patients and insulin in 30.3%. Median systolic and diastolic blood pressure at recruitment is 135 (125;146) and 80
(72;85) mmHg, 65.4% of subjects received RAAS blocking agents. Mean eGFR is 80.7±29.2
ml/min/1.73m2
and median baseline albumin/creatinine ratio 8.3 mg (IQR: 3.8 and 25.1).
Conclusion: PROVALID will provide information on incidence and progression of renal and
cardiovascular disease and therapy in patients with type 2 diabetes mellitus in different
European countries. Thus, in contrast to many other cohort studies we will be able to associate
national clinical practise pattern with outcome in this highly vulnerable patient population
Multicentric validation of proteomic biomarkers in urine specific for diabetic nephropathy
Background: Urine proteome analysis is rapidly emerging as a tool for diagnosis and prognosis in disease states. For diagnosis of diabetic nephropathy (DN), urinary proteome analysis was successfully applied in a pilot study. The validity of the previously established proteomic biomarkers with respect to the diagnostic and prognostic potential was assessed on a separate set of patients recruited at three different European centers. In this case-control study of 148 Caucasian patients with diabetes mellitus type 2 and duration >= 5 years, cases of DN were defined as albuminuria >300 mg/d and diabetic retinopathy (n = 66). Controls were matched for gender and diabetes duration (n = 82).
Methodology/Principal Findings: Proteome analysis was performed blinded using high-resolution capillary electrophoresis coupled with mass spectrometry (CE-MS). Data were evaluated employing the previously developed model for DN. Upon unblinding, the model for DN showed 93.8% sensitivity and 91.4% specificity, with an AUC of 0.948 (95% CI 0.898-0.978). Of 65 previously identified peptides, 60 were significantly different between cases and controls of this study. In <10% of cases and controls classification by proteome analysis not entirely resulted in the expected clinical outcome. Analysis of patient's subsequent clinical course revealed later progression to DN in some of the false positive classified DN control patients.
Conclusions: These data provide the first independent confirmation that profiling of the urinary proteome by CE-MS can adequately identify subjects with DN, supporting the generalizability of this approach. The data further establish urinary collagen fragments as biomarkers for diabetes-induced renal damage that may serve as earlier and more specific biomarkers than the currently used urinary albumin
Biharmonic pattern selection
A new model to describe fractal growth is discussed which includes effects
due to long-range coupling between displacements . The model is based on the
biharmonic equation in two-dimensional isotropic defect-free
media as follows from the Kuramoto-Sivashinsky equation for pattern formation
-or, alternatively, from the theory of elasticity. As a difference with
Laplacian and Poisson growth models, in the new model the Laplacian of is
neither zero nor proportional to . Its discretization allows to reproduce a
transition from dense to multibranched growth at a point in which the growth
velocity exhibits a minimum similarly to what occurs within Poisson growth in
planar geometry. Furthermore, in circular geometry the transition point is
estimated for the simplest case from the relation
such that the trajectories become stable at the growing surfaces in a
continuous limit. Hence, within the biharmonic growth model, this transition
depends only on the system size and occurs approximately at a distance far from a central seed particle. The influence of biharmonic patterns on
the growth probability for each lattice site is also analysed.Comment: To appear in Phys. Rev. E. Copies upon request to
[email protected]
The Physicist's Guide to the Orchestra
An experimental study of strings, woodwinds (organ pipe, flute, clarinet,
saxophone and recorder), and the voice was undertaken to illustrate the basic
principles of sound production in music instruments. The setup used is simple
and consists of common laboratory equipment. Although the canonical examples
(standing wave on a string, in an open and closed pipe) are easily reproduced,
they fail to explain the majority of the measurements. The reasons for these
deviations are outlined and discussed.Comment: 11 pages, 10 figures (jpg files). Submitted to European Journal of
Physic
Circulating matrix metalloproteinases are associated with arterial stiffness in patients with type 1 diabetes: pooled analysis of three cohort studies
BACKGROUND: Altered regulation of extracellular matrix (ECM) composition by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) may contribute to arterial stiffening. We investigated associations between circulating MMP-1, -2, -3, -9, -10 and TIMP-1, and carotid-femoral pulse wave velocity (cfPWV) and pulse pressure (PP), as markers of arterial stiffness in type 1 diabetic patients.
METHODS: Individuals with type 1 diabetes from three different cohorts were included in this study: EURODIAB Prospective Complications study (n = 509), LEACE (n = 370) and PROFIL (n = 638). Linear regression analyses were used to investigate cross-sectional associations between circulating levels of MMP-1, -2, -3, -9, -10, and TIMP-1 and cfPWV (n = 614) as well as office PP (n = 1517). Data on 24-h brachial and 24-h central PP were available in 638 individuals from PROFIL. Analyses were adjusted for age, sex, duration of diabetes, HbA1c, mean arterial pressure (MAP), and eGFR, and additionally for other cardiovascular risk factors and presence of vascular complications.
RESULTS: After adjustment for potential confounders and presence of vascular complications, circulating MMP-3 was associated with cfPWV [β per 1 SD higher lnMMP3 0.29 m/s (0.02; 0.55)]. In addition, brachial and central 24-h PP measurements in PROFIL were significantly associated with MMP-2 [(1.40 (0.47:2.33) and 1.43 (0.63:2.23)]. Pooled data analysis showed significant associations of circulating levels of MMP-1 and MMP-2 with office PP [β per 1 SD higher lnMMP-1 and lnMMP-2 = − 0.83 mmHg (95% CI − 1.50; − 0.16) and = 1.33 mmHg (0.55; 2.10), respectively].
CONCLUSIONS: MMPs-1, -2, and -3 are independently associated with markers of arterial stiffening in patients with type 1 diabetes and may become therapeutic targets
Efficacy and Safety of Liraglutide Versus Placebo as Add-on to Glucose-Lowering Therapy in Patients With Type 2 Diabetes and Moderate Renal Impairment (LIRA-RENAL): A Randomized Clinical Trial
Objective Renal impairment in type 2 diabetes limits available glucose-lowering treatment options. This trial was conducted to establish the efficacy and safety of liraglutide as an add-on to existing glucose-lowering medications in patients with inadequately controlled type 2 diabetes and moderate renal impairment. Research Design and Methods In this 26-week, double-blind trial, 279 patients with HbA1c 7-10%, BMI 20-45 kg/m2, and moderate renal impairment (estimated glomerular filtration rate [eGFR] 30-59 mL/min/1.73 m2; MDRD) were randomized (1:1) to once-daily liraglutide 1.8 mg (n = 140) or placebo (n = 139). Results The estimated treatment difference in HbA1c from baseline to week 26 was 20.66% (27.25 mmol/mol) (95% CI 20.90 to 20.43 [29.82 to 24.69]), P < 0.0001). Fasting plasma glucose decreased more with liraglutide (21.22 mmol/L [222.0 mg/dL]) than with placebo (20.57mmol/L [210.3mg/dL], P = 0.036). Therewas a greater reduction in body weight with liraglutide (22.41 kg) thanwith placebo (21.09 kg, P = 0.0052).No changes in renal function were observed (eGFR relative ratio to baseline:21% liraglutide, +1% placebo; estimated treatment ratio [ETR] 0.98, P = 0.36). The most common adverse events were gastrointestinal (GI) adverse effects (liraglutide, 35.7%; placebo, 17.5%). No difference in hypoglycemic episodes was observed between treatment groups (event rate/100 patient-years of exposure: liraglutide, 30.47; placebo, 40.08; P = 0.54). The estimated ratio to baseline for lipase was 1.33 for liraglutide and 0.97 for placebo (ETR 1.37, P < 0.0001). Conclusions Liraglutide did not affect renal function and demonstrated better glycemic control, with no increase in hypoglycemia risk but with higher withdrawals due to GI adverse events than placebo in patients with type 2 diabetes and moderate renal impairment.</p
BRCA2 polymorphic stop codon K3326X and the risk of breast, prostate, and ovarian cancers
Background: The K3326X variant in BRCA2 (BRCA2*c.9976A>T; p.Lys3326*; rs11571833) has been found to be associated with small increased risks of breast cancer. However, it is not clear to what extent linkage disequilibrium with fully pathogenic mutations might account for this association. There is scant information about the effect of K3326X in other hormone-related cancers.
Methods: Using weighted logistic regression, we analyzed data from the large iCOGS study including 76 637 cancer case patients and 83 796 control patients to estimate odds ratios (ORw) and 95% confidence intervals (CIs) for K3326X variant carriers in relation to breast, ovarian, and prostate cancer risks, with weights defined as probability of not having a pathogenic BRCA2 variant. Using Cox proportional hazards modeling, we also examined the associations of K3326X with breast and ovarian cancer risks among 7183 BRCA1 variant carriers. All statistical tests were two-sided.
Results: The K3326X variant was associated with breast (ORw = 1.28, 95% CI = 1.17 to 1.40, P = 5.9x10- 6) and invasive ovarian cancer (ORw = 1.26, 95% CI = 1.10 to 1.43, P = 3.8x10-3). These associations were stronger for serous ovarian cancer and for estrogen receptor–negative breast cancer (ORw = 1.46, 95% CI = 1.2 to 1.70, P = 3.4x10-5 and ORw = 1.50, 95% CI = 1.28 to 1.76, P = 4.1x10-5, respectively). For BRCA1 mutation carriers, there was a statistically significant inverse association of the K3326X variant with risk of ovarian cancer (HR = 0.43, 95% CI = 0.22 to 0.84, P = .013) but no association with breast cancer. No association with prostate cancer was observed.
Conclusions: Our study provides evidence that the K3326X variant is associated with risk of developing breast and ovarian cancers independent of other pathogenic variants in BRCA2. Further studies are needed to determine the biological mechanism of action responsible for these associations
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