Environmental Change at Deep-Sea Sponge Habitats Over the Last Half Century: A Model Hindcast Study for the Age of Anthropogenic Climate Change

Deep-sea sponges inhabit multiple areas of the deep North Atlantic at depths below 250 m. Living in the deep ocean, where environmental properties below the permanent thermocline generally change slowly, they may not easily acclimatize to abrupt changes in the environment. Until now consistent monitoring timeseries of the environment at deep sea sponge habitats are missing. Therefore, long-term simulation with coupled bio-physical models can shed light on the changes in environmental conditions sponges are exposed to. To investigate the variability of North Atlantic sponge habitats for the past half century, the deep-sea conditions have been simulated with a 67-year model hindcast from 1948 to 2014. The hindcast was generated using the ocean general circulation model HYCOM, coupled to the biogeochemical model ECOSMO. The model was validated at known sponge habitats with available observations of hydrography and nutrients from the deep ocean to evaluate the biases, errors, and drift in the model. Knowing the biases and uncertainties we proceed to study the longer-term (monthly to multi-decadal) environmental variability at selected sponge habitats in the North Atlantic and Arctic Ocean. On these timescales, these deep sponge habitats generally exhibit small variability in the water-mass properties. Three of the sponge habitats, the Flemish Cap, East Greenland Shelf and North Norwegian Shelf, had fluctuations of temperature and salinity in 4–6 year periods that indicate the dominance of different water masses during these periods. The fourth sponge habitat, the Reykjanes Ridge, showed a gradual warming of about 0.4°C over the simulation period. The flux of organic matter to the sea floor had a large interannual variability, that, compared to the 67-year mean, was larger than the variability of primary production in the surface waters. Lateral circulation is therefore likely an important control mechanism for the influx of organic material to the sponge habitats. Simulated oxygen varies interannually by less than 1.5 ml/l and none of the sponge habitats studied had oxygen concentrations below hypoxic levels. The present study establishes a baseline for the recent past deep conditions that future changes in deep sea conditions from observations and climate models can be evaluated against.publishedVersio

Key physical processes and their model representation for projecting climate impacts on subarctic Atlantic net primary production: A synthesis

Oceanic net primary production forms the foundation of marine ecosystems. Understanding the impact of climate change on primary production is therefore critical and we rely on Earth System Models to project future changes. Stemming from their use of different physical dynamics and biogeochemical processes, these models yield a large spread in long-term projections of change on both the global and regional scale. Here we review the key physical processes and biogeochemical parameterizations that influence the estimation of primary production in Earth System Models and synthesize the available projections of productivity in the subarctic regions of the North Atlantic. The key processes and modelling issues we focus on are mixed layer depth dynamics, model resolution and the complexity and parameterization of biogeochemistry. From the model mean of five CMIP6 models, we found a large increase in PP in areas where the sea ice retreats throughout the 21st century. Stronger stratification and declining MLD in the Nordic Seas, caused by sea ice loss and regional freshening, reduce the vertical flux of nutrients into the photic zone. Following the synthesis of the primary production among the CMIP6 models, we recommend a number of measures: constraining model hindcasts through the assimilation of high-quality long-term observational records to improve physical and biogeochemical parameterizations in models, developing better parameterizations for the sub-grid scale processes, enhancing the model resolution, downscaling and multi-model comparison exercises for improved regional projections of primary production.publishedVersio

Controls on carbon export in the subtropical North Atlantic

We present a lower trophic level pelagic ecosystem model that allows the investigation of the role of hydrography, bacterial remineralization and detritus consumption on the strength of carbon export and its attenuation. We apply the model to investigate the controls on the carbon export at the Bermuda Atlantic Time-Series Study site (BATS) and the European Station for Time series in the Ocean, Canary Islands (ESTOC) in the subtropical North Atlantic. In previous field studies, export ratios at 200 m (the ratio between particulate carbon export below the euphoric zone and primary production) were found to be 300-400% smaller at ESTOC compared to BATS. Our model results show that the magnitude and temporal variability of primary productivity and modeled carbon export are modulated by the intensity and duration of vertical mixing events. BATS, with a more dynamic physical environment, has winter mixed-layer depths on average 80 m deeper than ESTOC and is characterized by pulses of enhanced productivity and export. Our model demonstrates the influence of hydrography on export attenuation through (i) more stable water column dynamics at ESTOC that increase particle remineralization time scales and weaken export strength at ESTOC compared to BATS; and (ii) higher water temperatures at BATS in the mesopelagic between 200 and 500 m that increase remineralization rates compared to ESTOC. This results in reduced differences in export ratios within the mesopelagic between both stations that is confirmed by observations. Strengthening remineralization through (i) adding zooplankton feeding on detritus and (ii) increasing bacterial remineralization rates decrease export at all depths at both stations, and increase the modeled difference in 200 m export ratios between BATS and ESTOC from 7% to 17%, a difference that is still much smaller than observed. While we could demonstrate the skill of our model in testing the mechanisms that could lead to differences in regional carbon export, our results indicate that hydrography-driven residence times, zooplankton feeding on detritus and enhanced bacterial remineralization rates alone are insufficient in driving export ratio differences between BATS and ESTOC. On the other hand, modeled export proved to be highly sensitive to prescribed particle sinking speeds. Thus, community and site dependent processes that lead to variations in particle sinking speed and remineralization, together with potential differences in vertical migration by zooplankton and horizontal transport, may be additional processes explaining the observed differences in export ratios at BATS and ESTOC

The determination of oleic acid contents in sunflower genotypes

High oleic sunflower is new trend both in Turkey and also in the world due to that it present healthy vegetable oil and also higher standing ability for frying. Higher oleic acid also affects from environment especially nigh temperatures during the grain filling period but genetic contribution is also important. High oleic acid content comes from Pervenent mutation in sunflower and it controlling Ol genes. However, because of being a seed trait which is determining after harvest, it is so difficult and unnecessary works (waiting even low oleic ones until seed treshing, etc) to select high oleic sunflower genetic materials. Therefore, selection utilization of molecular markers for determining of higher oleic types help breeders a lot to select accurately high oleic ones and also reduce costs both workers, isolation material, etc… The study covers determining of higher oleic type sunflower genetic materials developed in National Sunflower Hybrid Breeding Project conducted by Trakya Agricultural Research Institute. To screen of high oleic acid genotypes, around 400 sunflower F2 and F3 individuals obtained from crosses between high oleic acid and low oleic acid lines were used in TUBITAK (The Scientific and Technological Research Council of Turkey) Project 1003-114O971. Fatty acids of sunflower genotypes were determined by Agilent 6850 Gas Chromatography in Trakya University Lab. Based on the study results, oleic acid contents of sunflower genotypes were changed between 21.9-91.8 %, linoleic acid contents of them between 1.1-66.5 %, palmitic acid contents of them were between 3.4-8.0 % and stearic acid contents of genotypes were changed between 1.1-9.7 %. The higher oleic types were selected based on the study results for further generations

A model hindcast of bottom environmental conditions in the North Atlantic Ocean 1948 to 2014

This dataset contains a model simulation of the environmental conditions close to the sea-floor from January 1948-April 2015. The simulations relies on the coupled physcial-biogeochemical HYCOM-ECOSMO and has been forced by a Global High Resolution Climate Reconstruction (ECHAM6). The dataset is monthly, it consist of temperature, salinity, currents, oxygen, nitrate, phosphate and silicate all interpolated to 1 meter above the sea floor. Additionally the dataset contains gross primary and secondary production integrated over the water column

Environmental Change at Deep-Sea Sponge Habitats Over the Last Half Century: A Model Hindcast Study for the Age of Anthropogenic Climate Change

Deep-sea sponges inhabit multiple areas of the deep North Atlantic at depths below 250 m. Living in the deep ocean, where environmental properties below the permanent thermocline generally change slowly, they may not easily acclimatize to abrupt changes in the environment. Until now consistent monitoring timeseries of the environment at deep sea sponge habitats are missing. Therefore, long-term simulation with coupled bio-physical models can shed light on the changes in environmental conditions sponges are exposed to. To investigate the variability of North Atlantic sponge habitats for the past half century, the deep-sea conditions have been simulated with a 67-year model hindcast from 1948 to 2014. The hindcast was generated using the ocean general circulation model HYCOM, coupled to the biogeochemical model ECOSMO. The model was validated at known sponge habitats with available observations of hydrography and nutrients from the deep ocean to evaluate the biases, errors, and drift in the model. Knowing the biases and uncertainties we proceed to study the longer-term (monthly to multi-decadal) environmental variability at selected sponge habitats in the North Atlantic and Arctic Ocean. On these timescales, these deep sponge habitats generally exhibit small variability in the water-mass properties. Three of the sponge habitats, the Flemish Cap, East Greenland Shelf and North Norwegian Shelf, had fluctuations of temperature and salinity in 4–6 year periods that indicate the dominance of different water masses during these periods. The fourth sponge habitat, the Reykjanes Ridge, showed a gradual warming of about 0.4°C over the simulation period. The flux of organic matter to the sea floor had a large interannual variability, that, compared to the 67-year mean, was larger than the variability of primary production in the surface waters. Lateral circulation is therefore likely an important control mechanism for the influx of organic material to the sponge habitats. Simulated oxygen varies interannually by less than 1.5 ml/l and none of the sponge habitats studied had oxygen concentrations below hypoxic levels. The present study establishes a baseline for the recent past deep conditions that future changes in deep sea conditions from observations and climate models can be evaluated against

Morphometry, asymmetry and variations of cerebral sulci on superolateral surface of cerebrum in autopsy cases

The cerebral sulci are known as main microanatomical borders that serve as a gateway and surgical passage to reach the ventricles or to the deeper lesions. It is a matter of curiosity that whether there is a convergence between the morphological asymmetry and the functional asymmetry, and also its significance in surgery. The aim of this study is make morphometric measurements and evaluate asymmetry of several sulci on the lateral aspects of the cerebrum in regard to main sulci and related reference key points

Planimetry investigation of the corpus callosum in temporal lobe epilepsy patients

OBJECTIVE: To evaluate the effects of temporal lobe epilepsy (TLE) on corpus callosum (CC) morphometry in patients with TLE. METHODS: This retrospective study was conducted at the Faculty of Medicine, Tekirdag Namik Kemal University, Tekirdag, Turkey between November 2010 and December 2013. The epileptic syndrome diagnosis was based on International League Against Epilepsy criteria, and this study was conducted on the MRIs of 25 epilepsy patients and 25 control subjects. We classified the patients according to their duration of epilepsy <10 and ≥10 years. The projection area length (PAL) of the CC was also estimated. Total brain volumes (TBV) were measured on CT images. RESULTS: The mean values of TBV for patients with TLE and the control group were not statistically different, but the CC PAL values were statistically different. The mean CC PAL values of under and over 25 years of age in patients with TLE were statistically different. The mean values of TBV of under and over 10 years duration of TLE were small statistically, but the CC PAL values were statistically different. CONCLUSION: The results indicate a clear influence of TLE on the structure of the CC rather than TBV

Aerobic and Anaerobic Exercise Capacities in Obstructive Sleep Apnea and Associations with Subcutaneous Fat Distributions

Obesity is a strong risk factor for the development and progression of sleep apnea. Responses to exercise by patients with obstructive sleep apnea syndrome (OSAS) are clinically relevant to reducing body weight and cardiovascular risk factors. This study aimed to clarify the aerobic and anaerobic exercise capacities and their possible relationships with other findings in patients with OSAS. Forty patients (30 males, 10 females) and 40 controls (30 males, 10 females) were enrolled in this study. Questionnaires (excessive daytime sleepiness, daytime tiredness, morning headache, waking unrefreshed, and imbalance), overnight polysomnography, indirect laryngoscopy, and aerobic and anaerobic exercise tests were performed. Triceps, subscapular, abdomen, and thigh skinfold thicknesses were measured. Subcutaneous abdominal fat (abdomen skinfold) was significantly higher in OSAS patients than in controls. Maximal anaerobic power and anaerobic capacity were not different significantly between the patients and controls. We found that aerobic capacity was significantly lower in OSAS patients than in controls. Aerobic capacity was negatively correlated with upper-body subcutaneous fat (triceps and subscapular skinfolds) but not correlated with subcutaneous abdominal fat in OSAS patients. In multivariate analyses using all patients, the apnea-hypopnea index remained a significant independent predictor of aerobic capacity after controlling for a variety of potential confounders including body mass index. Our data confirm that central obesity (subcutaneous abdominal fat) is prominent in patients with OSAS. Our results suggest that lower aerobic exercise capacity in patients with OSAS might be due to daily physical activity that is restricted by OSA itself. This study also suggests that the degree of subcutaneous abdominal fat cannot be used for predicting aerobic capacity level. We think that upper-body subcutaneous fat might be suitable for determining the physical fitness of patients with OSAS