Data Descriptor : A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins

Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ecosystem resilience, an in-depth understanding of ecological processes is urgently needed. Lakes, as providers of numerous ecosystem services, face multiple stressors that threaten their functioning. Harmful cyanobacterial blooms are a persistent problem resulting from nutrient pollution and climate-change induced stressors, like poor transparency, increased water temperature and enhanced stratification. Consistency in data collection and analysis methods is necessary to achieve fully comparable datasets and for statistical validity, avoiding issues linked to disparate data sources. The European Multi Lake Survey (EMLS) in summer 2015 was an initiative among scientists from 27 countries to collect and analyse lake physical, chemical and biological variables in a fully standardized manner. This database includes in-situ lake variables along with nutrient, pigment and cyanotoxin data of 369 lakes in Europe, which were centrally analysed in dedicated laboratories. Publishing the EMLS methods and dataset might inspire similar initiatives to study across large geographic areas that will contribute to better understanding lake responses in a changing environment.Peer reviewe

Stratification strength and light climate explain variation in chlorophyll a at the continental scale in a European multilake survey in a heatwave summer

To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L−1), and its subsets (2 depth types and 3 climatic zones), show that light climate and stratification strength were the most significant explanatory variables for chlorophyll a (Chl a) variance. TN was a significant predictor for phytoplankton biomass for shallow and continental lakes, while TP never appeared as an explanatory variable, suggesting that under high TP, light, which partially controls stratification strength, becomes limiting for phytoplankton development. Mediterranean lakes were the warmest yet most weakly stratified and had significantly less Chl a than Boreal lakes, where the temperature anomaly from the long-term average, during a summer heatwave was the highest (+4°C) and showed a significant, exponential relationship with stratification strength. This European survey represents a summer snapshot of phytoplankton biomass and its drivers, and lends support that light and stratification metrics, which are both affected by climate change, are better predictors for phytoplankton biomass in nutrient-rich lakes than nutrient concentrations and surface temperature

Evaluation of microdissection testicular sperm extraction results in patients with non-obstructive azoospermia: Independent predictive factors and best cutoff values for sperm retrieval

PubMed: 26706742Purpose: Testicular sperm extraction (TESE) for intracytoplasmic sperm injection (ICSI) was first introduced for the treatment of non-obstructive azoospermia. This study was conducted to detect predictive factors affecting the success of microTESE. Materials and Methods: We retrospectively evaluated the results of 191 cases who underwent microTESE. For each patient, the testicular volume, endocrine profile [follicle stimulating hormone (FSH), luteinizing hormone (LH), free testosterone (FT), total testosterone (TT)], serum inhibin B level, karyotype analysis, and Y chromosome microdeletions were recorded, and all data were analyzed to detect any predictors. The receiver operating characteristic curve, two-sample t-test and regression analysis were used for the statistical analysis. Results: The mean age of the patients was 34.4 ± 5.6 years. Sperm retrieval was successful in 104 (54.5%) patients, and there was no sperm in 87 (45.5%). Seven factors including, testicular size, Johnson score, Y chromosome microdeletion, and serum FSH, LH, FT and TT levels were different between the successful and unsuccessful groups. Six patients had Klinefelter syndrome, and ten patients (5.2%) had a Y chromosome microdeletion (5 AZF-c, 1 AZF-b, 2 AZF-bc, 1 AZF-abc, and 1 AZF-ac). The Johnson score, TT level, family history and Y chromosome microdeletions were determined to be independent predictive factors for sperm found. According to the testicular histology, the sperm-found ratios were 36%, 48.6%, and 95.5% in the sertoli cell only syndrome, maturation arrest, and hypospermatogenesis groups, respectively. Conclusion: According to our results, the Johnson score, TT level, family history-related infertility, and Y chromosome microdeletions were determined to be independent predictive factors for sperm found

Autonomic nervous system dysfunction in lifelong premature ejaculation: Analysis of heart rate variability

PubMed: 23102443Objective: To identify autonomic nervous dysfunction in patients with lifelong premature ejaculation. Methods: The study participants were 25 men with lifelong premature ejaculation and 25 healthy controls. The parameters of 24-hour heart rate variability that are influenced by the autonomic nervous system were compared between the men with lifelong premature ejaculation and the healthy controls. Results: The laboratory results of all patients were within normal limits, and no significant differences were found between the patients and the controls in age, body weight, and body mass index. A low-frequency signal that is influenced by the sympathetic system was increased in the patients (P =.026). Furthermore, a high-frequency signal that is influenced by the parasympathetic system was decreased in the patients (P =.011). Finally, the low frequency-to-high frequency ratio, an indicator of the balance between the two components of the autonomic nervous system, was increased in the patients (P =.002). Conclusion: To our knowledge, no study has investigated the influence of the autonomic nervous system on 24-hour heart rate variability in premature ejaculation. In the present study, sympathetic activity was increased in men with lifelong premature ejaculation; this overactivity might lead to lifelong premature ejaculation. Additional studies are required to reveal the possible alteration of the autonomic nervous system in premature ejaculation. © 2012 Elsevier Inc. All Rights Reserved