Plasticity in dendroclimatic response across the distribution range of Aleppo pine (Pinus halepensis)

We investigated the variability of the climate-growth relationship of Aleppo pine across its distribution range in the Mediterranean Basin. We constructed a network of tree-ring index chronologies from 63 sites across the region. Correlation function analysis identified the relationships of tree-ring index to climate factors for each site. We also estimated the dominant climatic gradients of the region using principal component analysis of monthly, seasonal, and annual mean temperature and total precipitation from 1,068 climatic gridpoints. Variation in ring width index was primarily related to precipitation and secondarily to temperature. However, we found that the dendroclimatic relationship depended on the position of the site along the climatic gradient. In the southern part of the distribution range, where temperature was generally higher and precipitation lower than the regional average, reduced growth was also associated with warm and dry conditions. In the northern part, where the average temperature was lower and the precipitation more abundant than the regional average, reduced growth was associated with cool conditions. Thus, our study highlights the substantial plasticity of Aleppo pine in response to different climatic conditions. These results do not resolve the source of response variability as being due to either genetic variation in provenance, to phenotypic plasticity, or a combination of factors. However, as current growth responses to inter-annual climate variability vary spatially across existing climate gradients, future climate-growth relationships will also likely be determined by differential adaptation and/or acclimation responses to spatial climatic variation. The contribution of local adaptation and/or phenotypic plasticity across populations to the persistence of species under global warming could be decisive for prediction of climate change impacts across populations. In this sense, a more complex forest dynamics modeling approach that includes the contribution of genetic variation and phenotypic plasticity can improve the reliability of the ecological inferences derived from the climate-growth relationships.This work was partially supported by Spanish Ministry of Education and Science co-funded by FEDER program (CGL2012-31668), the European Union and the National Ministry of Education and Religion of Greece (EPEAEK- Environment – Archimedes), the Slovenian Research Agency (program P4-0015), and the USDA Forest Service. The cooperation among international partners was supported by the COST Action FP1106, STREeSS

Dyslipidemia and cardiovascular risk assessment in HIV-positive patients [HIV pozitif hastalarda dislipidemi ve kardiyovasküler risk degerlendirilmesi]

PubMed ID: 28424436Objective: Dyslipidemia is a major complication of antiretroviral treatment. Aim of the present study was to screen baseline lipid levels and cardiovascular disease risk in HIV-positive patients and analyze change in those parameters after initiation of antiretroviral treatment (ART). Methods: HIV-positive patients who presented at our clinic between April 2011 and August 2012 were included. Study included 19 female (22.1%) and 67 male (77.9%) patients (mean age 39.5±10.3 years). Blood pressure, smoking habit, alcohol consumption, serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), glucose level, and antiretroviral treatment status data were reviewed retrospectively. Changes in lipid profile and lifetime risk for atherosclerotic cardiovascular disease (ASCVD) according to the American College of Cardiology guidelines were compared with baseline data and analyzed. Results: At baseline, 13 (15.1%) patients were already receiving ART and 73 (84.9%) patients were treatment-naive or had stopped therapy ?3 months prior to enrollment. At last visit, 73 (84.9%) patients were taking ART. Results of baseline and final visit TC levels were 175.5 mg/dL (range: 90-346 mg/dL) and 196.5 mg/dL (range: 104-317 mg/dL), respectively (p=0.001). HDL levels were 40 mg/dL (range: 21-81 mg/dL) and 35 mg/dL (range: 10-75 mg/dL; p=0.001), and LDL levels were 101.5 mg/dL (range: 32-191 mg/dL) and 120.5 mg/dL (range: 32-250 mg/dL; p<0.001). TG levels were 145.5 mg/dL (range: 43-2580 mg/dL and 152.5 mg/dL (range: 67-884 mg/dL; p=0.102). Baseline ASCVD risk score was 46% (range: 5-69%) while last visit ASCVD risk score was 50% (range: 5-69%; p<0.001). Conclusion: HIV infection has adverse effects on lipid profiles and cardiovascular risk of HIV-positive patients. Therefore, patients should be closely monitored for lifestyle interventions and lipid-lowering agents. © 2017 Türk Kardiyoloji Dernegi