pinecone/core-2020-05-10-deduplication huggingface dataset:
Completion lymphadenectomy for sentinel node positive cutaneous head & neck melanoma

The application and utility of melanoma sentinel lymph node biopsy (SLNB) has evolved significantly since its inception over two decades ago. The current focus has shifted from a staging modality to potentially a therapeutic intervention. Recent research to include large multi-institutional randomized trials have attempted to answer the question: is a completion lymph node dissection (CLND) required following a positive SLNB? This review provides an evidence-based, contemporary review of the utility of CLND for SLNB positive head and neck cutaneous melanoma patients
Perineural invasion in squamous cell carcinoma of the oral cavity: histology, tumor stage and outcome

Objectives/Hypothesis: To analyze the impact of different types of perineural invasion (PNI) in squamous cell carcinoma (SCC) of the oral cavity on overall survival and recurrence rate, with a special focus on histologic subtypes and tumor stage.\ud
Study Design: Retrospective case-control study with clinicopathological analysis.\ud
Methods: Seventeen patients who received primary surgical treatment for SCC of the oral cavity with PNI were matched to a control group. In a histologic review, PNI was classified into subtypes according to an adapted Liebig classification. The term type A was used to describe tumor invasion into the nerve, whereas type B was used to describe circumferential growth around the nerve. Clinical charts were reviewed, and a Kaplan-Meier survival analysis was performed.\ud
Results: The recurrence-free survival rates were 47.1% versus 80.4% (PNI vs. matched control group, P < 0.05), 60.0% versus 94.1% (PNI in stage I and II disease vs. matched control group, P < 0.05) and 41.7% versus 73.5% (PNI in stage III and IV disease vs. matched control group, P < 0.05). In most cases (n = 9) of PNI, both histologic subtypes (type A and type B) were present. Five cases exclusively showed type A, and three cases exclusively showed type B.\ud
Conclusions: Perineural invasion in early disease oral carcinoma has a particularly high impact on survival. Both histologic subtypes showed a significantly worse recurrence-free survival rate when compared to the control group.\ud
Level of Evidence: 3
Microbial production of conjugated fatty acids

Conjugated fatty acids have attracted much attention as a novel type of biologically beneficial functional lipid. Some isomers of conjugated linoleic acid (CLA) reduce carcinogenesis, atherosclerosis and body fat. Considering the use of CLA for medicinal and nutraceutical purposes, a safe isomer-selective process of production is required. The introduction of biological reactions for CLA production could be an answer. We screened microbial reactions useful for CLA production and found several unique reactions in microorganisms. Lactic acid bacteria produced CLA from linoleic acid. The CLA, which was obtained as the free fatty acid form, comprised a mixture of cis-9, trans-11- octadecadienoic acid (18:2) and trans-9, trans-11-18:2. Furthermore, lactic acid bacteria transformed ricinoleic acid [12-hydroxy-cis-9- octadecenoic acid (18:1)] to CLA (a mixture of cis-9, trans-11-18:2 and trans-9, trans-11-18:2). Castor oil, rich in the triacylglycerol form of ricinoleic acid, was also found to act as a substrate for CLA production by lactic acid bacteria with the aid of lipase-catalyzed triacylglycerol hydrolysis. Filamentous fungi transformed trans-vaccenic acid (trans-11-18:1) to cis-9, trans-11-18:2 by Δ9 desaturation.This CLA was obtained as a triacylglycerol.In addition, lactic acid bacteria produced conjugated trienoic fatty acids from α- and γ-linolenic acid. The trienoic fatty acids produced from α-linolenic acid were cis-9, trans-11, cis-15-octadecatrienoic acid (18:3) and trans-9, trans-11, cis-15-18:3. Those produced from γ-clinolenic acid were cis-6, cis-9, trans-11-18:3 and cis-6, trans-9, trans-11-18:3
Lipidomic analysis of fats and oils – a lot more than just omega-3

TKS research is supported in part by the Wellcome Trust, SUSLA, BBSRC and the European Community’s Seventh Framework Programme under grant agreement No. 602773 (Project KINDReD)Edible oils and fats are among the most abundant cooking ingredients in the world, and are an important part of a healthy balanced diet, especially if they are high in omega-6 and omega-3 polyunsaturated fatty acids. Rather than just the total fatty acid compositions, the analysis of individual lipid species within these oils and fats has become increasingly important. Within the past decade several mass spectrometric lipidomics methods have been adapted and applied to the analysis of edible oils and fats. These methodologies are vital for the analysis of a plethora of lipid species that will be important for numerous health and sustainability issues in the future.PostprintPeer reviewe
Elevating the predatory effect: Sensory‐scanning foraging strategy by the lobate ctenophore Mnemiopsis leidyi

The influential predatory role of the lobate comb jellyfish Mnemiopsis leidyi has largely been attributed to the generation of a hydrodynamically silent feeding current to entrain and initiate high encounter rates with prey. However, for high encounter rates to translate to high ingestion rates, M. leidyi must effectively capture the entrained prey. To investigate the capture mechanisms, we recorded and quantified, using three-dimensional videography, the outcome of encounter events with slow swimming Artemia prey. The auricles, which produce the feeding current of M. leidyi, were the primary encounter structures, first contacting 59% of the prey in the feeding current. Upon detection, the auricles manipulated the Artemia to initiate captures on the tentillae, which are coated with sticky cells (colloblasts). Using this mechanism of sensory-scanning to capture prey entrained in the feeding current, M. leidyi uses a similar foraging strategy to that of feeding-current foraging copepods. As such, M. leidyi has a higher capture efficiency than do medusae, contributing to the greater predatory effect of M. leidyi in both its endemic and invasive ecosystems
Absence of a priming effect on dissolved organic carbon degradation in lake water

The idea that small amounts of labile organic carbon might trigger the degradation of previously unreactive organic matter has attracted increasing scientific interest across multiple disciplines. Although this phenomenon, referred to as priming, has been widely reported in soils, evidence in freshwater systems is scarce and inconclusive. Here, we use a multifactorial microcosm experiment to test the conditions under which priming may be observed in freshwater ecosystems. We assessed the effect of pulse additions of three labile carbon sources (acetate, glucose, and cellobiose) on dissolved organic carbon (DOC) consumption using water from lakes with different trophic states (eutrophic to oligotrophic and clear to brownwater lakes). We further analyzed the effect of nutrient availability and the role of attachment of cells to surfaces. Despite the range of conditions tested, we found no clear evidence of a priming effect on DOC degradation, indicating that priming in freshwater systems may be of limited importance
Combined effects of CO2 and temperature on carbon uptake and partitioning by the marine diatoms Thalassiosira weissflogii and Dactyliosolen fragilissimus

Carbon uptake and partitioning of two globally abundant diatom species, Thalassiosira weissflogii and Dactyliosolen fragilissimus, was investigated in batch culture experiments under four conditions: ambient (15 degrees C, 400 atm), high CO2 (15 degrees C, 1000 atm), high temperature (20 degrees C, 400 atm), and combined (20 degrees C, 1000 atm). The experiments were run from exponential growth into the stationary phase (six days after nitrogen depletion), allowing us to track biogeochemical dynamics analogous to bloom situations in the ocean. Elevated CO2 had a fertilizing effect and enhanced uptake of dissolved inorganic carbon (DIC) by about 8% for T. weissflogii and by up to 39% for D. fragilissimus. This was also reflected in higher cell numbers, build-up of particulate and dissolved organic matter, and transparent exopolymer particles. The CO2 effects were most prominent in the stationary phase when nitrogen was depleted and CO2(aq) concentrations were low. This indicates that diatoms in the high CO2 treatments could take up more DIC until CO2 concentrations in seawater became so low that carbon limitation occurs. These results suggest that, contrary to common assumptions, diatoms could be highly sensitive to ongoing changes in oceanic carbonate chemistry, particularly under nutrient limitation. Warming from 15 to 20 degrees C had a stimulating effect on one species but acted as a stressor on the other species, highlighting the importance of species-specific physiological optima and temperature ranges in the response to ocean warming. Overall, these sensitivities to CO2 and temperature could have profound impacts on diatoms blooms and the biological pump
Turbulence effects on phytoplankton morpho-functional traits selection

International audienceTurbulence can regulate phytoplankton community structure in aquatic ecosystems by affecting sedimentation and nutrient acquisition. In rivers, nutrient concentrations are often high enough to sustain phytoplankton growth without limitation. Hence, turbulence mainly acts on phytoplankton by controlling its vertical position in such ecosystems. We conducted a laboratory experiment to see if the response of phytoplankton to turbulence could be predicted from morphofunctional traits related to sinking velocity and maximum growth rate. Turbulence was generated by horizontally oscillating grid systems in three 5 L chambers, which also constituted three chemostats. Two turbulence levels typical of lowland rivers (E57.931025m2 s23 and E57.831023m2 s23) were tested on an experimental community composed of six species from different taxonomic lineages. The species selected displayed different values for five morphofunctional traits related to sinking velocity and maximum growth rate (S : V ratio, algal unit size, density, shape, and motility). We showed that community structure could be partly predicted from morphofunctional traits. Under low turbulence (LT) (E57.931025m2 s23), species displaying traits leading to high sinking velocity (i.e., large size and high density) were unable to sustain stable populations, whereas species which displayed the opposite traits (i.e., small size, flattened shape, or low density) dominated the community. Furthermore, one of the six species exhibited phenotypic plasticity in size and could adapt to both high and LT conditions
Early development of Calanus glacialis and C. finmarchicus

Egg and nauplii development of coexisting populations of Calanus glacialis and C. finmarchicus from Disko Bay, western Greenland, were measured in the laboratory with, and without addition of food. Egg hatching rate was measured at five temperatures from 0°C to 10°C and the fit to a Belěhrádek equation was highly significant (r2 > 0.99). There was little difference between hatching and development rates of the two species; however, the egg hatching rate at low temperatures was faster than predicted from measurements made in other areas. Also, nauplii development times at 0°C were similar, with C. glacialis and C. finmarchicus reaching nauplii stage N6 after 44 d and 48 d, respectively. The laboratory-reared nauplii could be separated accurately to species by stage and length alone. However, separation by size was not possible for the in situ community of nauplii where the influence of food, temperature, and size-dependent predation mortality, made the size distribution more variable and overlapping
Multiple environmental changes induce interactive effects on bacterial degradation activity in the Arctic Ocean

The Arctic Ocean faces multiple environmental changes induced by climate change on both global and regional scale. In addition to global changes in seawater temperature and pH, Arctic waters receive organic matter enrichment due to increasing pelagic primary production, enhanced sea ice melting and increasing terrestrial carbon loads. We experimentally tested individual and combined effects of warming, acidification and organic matter amendment on growth, biomass production and extracellular enzyme activities of bacterioplankton in Fram Strait during early summer. Results reveal pH optima of 6.7–7.6 for extracellular leucine-aminopeptidase and below pH 6.0 for beta-glucosidase in the West Spitsbergen Current. These optima well below the current seawater pH imply increasing hydrolytic activity with ongoing ocean acidification. However, the new synthesis of extracellular enzymes during 4-d incubations obscured the biochemical pH effects. Elevated temperature and carbohydrate supply had strongly interactive effects on bacterial biomass production in both Atlantic Water of the West Spitsbergen Current and Polar Water of the East Greenland Current. Activation energies ranged from 45 kJ mol−1 to 52 kJ mol−1 at in situ substrate concentration, while substantially higher values of 122–174 kJ mol−1 could be estimated from incubations with carbohydrate addition. The net loss of total amino acids in carbohydrate-amended incubations was significantly reduced at elevated temperature in all experiments, suggesting enhanced de novo synthesis. Our findings show that the complexity of combined effects must be considered to better assess the potential of climate change to alter biogenic carbon and energy fluxes in marine systems
Resource allocation by the marine cyanobacterium Synechococcus WH8102 in response to different nutrient supply ratios

Differences in relative availability of nitrate vs. phosphate may contribute to regional variations in plankton elemental stoichiometry. As a representative of the globally abundant marine Synechococcus, strain WH8102 was grown in 16 chemostats up to 52  d at a fixed growth rate with nitrogen–phosphorus ratios (N : Psupply) of 1–50. Initially, the phosphate and nitrate concentrations in the vessel decreased when the respective nutrient was limiting. Cell growth generally stabilized, although several chemostats had apparent oscillations in biomass. We observed extensive plasticity in the elemental content and ratios. N : Pcell matched the supply values between N : Psupply 5 and 20. The C : Pcell followed a similar trend. In contrast, the mean C : Ncell was 6.8 and did not vary as a function of supply ratios. We also observed that induction of alkaline phosphatase, the fraction of P allocated to nucleic acids, and the lipid sulfoquinovosyldiacylglycerol : phosphatidyglycerol ratio inversely correlated with P availability. Our results suggest that this extensive plasticity in the elemental content and ratios depends both on the external nutrient availability as well as past growth history. Thus, our study provides a quantitative understanding of the regulation of the elemental stoichiometry of an abundant ocean phytoplankton lineage
Dissolved silicon isotopic compositions in the East China Sea: Water mass mixing vs. biological fractionation

We present the first set of dissolved silicon isotope data in seawater (delta Si-30(Si(OH)4)) from the East China Sea, a large and productive marginal sea significantly influenced by the Kuroshio Current and freshwater inputs from the Changjiang (Yangtze River). In summer (August 2009), the lowest surface delta Si-30(Si(OH)4) signatures of +2.1 parts per thousand corresponding to the highest Si(OH)(4) concentrations (similar to 30.0 mu mol L-1) were observed nearshore in Changjiang Diluted Water. During advection on the East China Sea inner shelf, surface delta Si-30(Si(OH)4) increased rapidly to +3.2 parts per thousand while Si(OH)(4) became depleted, indicating increasing biological utilization of the Si(OH)(4) originating from the Changjiang Diluted Water. This is also reflected in the water column profiles characterized by a general decrease of delta Si-30(Si(OH)4) and an increase of Si(OH)(4) with depth on the East China Sea mid-shelf and slope. In winter (December 2009-January 2010), however, the delta Si-30(Si(OH)4) was nearly constant at +1.9 parts per thousand throughout the water column on the East China Sea shelf beyond the nearshore, which was a consequence of enhanced vertical mixing of the Kuroshio subsurface water. Horizontal admixture of Kuroshio surface water, which is highly fractionated in Si isotopes, was observed only beyond the shelf break. Significant seasonal differences in delta Si-30(Si(OH)4) were detected in the surface waters beyond the Changjiang Diluted Water-influenced region on the East China Sea shelf, where the winter values were similar to 1.0 parts per thousand lower than those in summer, despite the same primary Si(OH)(4) supply from the Kuroshio subsurface water during both seasons. This demonstrates significantly higher biological consumption and utilization of Si(OH)(4) in summer than in winter
The modulating effect of light intensity on the response of the coccolithophore Gephyrocapsa oceanicato ocean acidification

Global change leads to a multitude of simultaneous modifications in the marine realm among which shoaling of the upper mixed layer, leading to enhanced surface layer light intensities, as well as increased carbon dioxide (CO2) concentration are some of the most critical environmental alterations for phytoplankton. In this study, we investigated the responses of growth, photosynthetic carbon fixation and calcification of the coccolithophore Gephyrocapsa oceanica to elevated inline image (51 Pa, 105 Pa, and 152 Pa) (1 Pa ≈ 10 μatm) at a variety of light intensities (50–800 μmol photons m−2 s−1). By fitting the light response curve, our results showed that rising inline image reduced the maximum rates for growth, photosynthetic carbon fixation and calcification. Increasing light intensity enhanced the sensitivity of these rate responses to inline image, and shifted the inline image optima toward lower levels. Combining the results of this and a previous study (Sett et al. 2014) on the same strain indicates that both limiting low inline image and inhibiting high inline image levels (this study) induce similar responses, reducing growth, carbon fixation and calcification rates of G. oceanica. At limiting low light intensities the inline image optima for maximum growth, carbon fixation and calcification are shifted toward higher levels. Interacting effects of simultaneously occurring environmental changes, such as increasing light intensity and ocean acidification, need to be considered when trying to assess metabolic rates of marine phytoplankton under future ocean scenarios
Effects of calcium and phosphorus limitation on the nutritional ecophysiology of Daphnia

This is the peer reviewed version of the following article: PRATER, C., WAGNER, N.D. and FROST, P.C., 2016. Effects of calcium and phosphorus limitation on the nutritional ecophysiology of D aphnia. Limnology and Oceanography, 61(1), pp. 268-278., which has been published in final form at https://doi.org/10.1002/lno.10208. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-ArchivingDeclines in environmental calcium (Ca) and phosphorus (P) concentrations have occurred over the past 30 yrs in lakes across the Canadian Shield in southern Ontario, and these reductions appear to be placing strong constraints on populations of Daphnia in this region. Here, we report results from a factorial manipulation of Ca concentrations and food P content under controlled laboratory conditions where we measured resulting changes in daphnid elemental content, individual growth and survival, and life history traits related\ud
to population growth. We found significant effects of Ca- and P-limitation on all variables measured; however, dietary P explained a majority of the variation in daphnid nutrient content and growth. Dietary effects of low P [high food carbon (C): P ratios] on individual Daphnia life-history traits also translated into significant population level effects. Dietary P also explained relatively more experimental variation in population level responses than Ca concentrations. Experimental Ca concentrations most strongly altered daphnid survival\ud
partly due to the use of a lethally low Ca concentration in our experiment. Although recent work examining shifts in zooplankton communities in this region mainly focuses on the effects of Ca-limitation, we show that Ca concentrations and food nutrient content, at levels commonly found on the Canadian Shield,\ud
are both likely to strongly alter Daphnia life-history and populations dynamics. Our results underscore the need to more fully examine how multielemental limitation (e.g., Ca, N, P) affects consumer physiology and life-history given the plausible translation of these effects on the community structure of lake  zooplankton
Macrophyte landscape modulates lake ecosystem-level nitrogen losses through tightly coupled plant-microbe interactions

11 páginas, 3 tablas, 5 figurasRoot functional diversity of submerged vegetation exerts a major effect on nitrogen (N) cycling in lake\ud
sediments. This fact, however, is neglected in current N-balance models because the links between the engineering\ud
role of plants and in situ microbial N cycling are poorly understood. We hypothesized that macrophyte\ud
species with high root oxygen loss (ROL) capacity promote the highest denitrification because of a\ud
higher abundance of ammonia oxidizers and tighter coupling between nitrifiers and denitrifier communities.\ud
We sampled five small ultraoligotrophic shallow lakes with abundant macrophyte cover including sediments\ud
dominated either by Isoetes spp. (high ROL), mixed communities of natopotamids (low ROL), and unvegetated\ud
sandy sediments. At each site, we quantified denitrification (DNT) rates and proxies for the abundance\ud
of denitrifiers (nirS and nirK genes), and both ammonia oxidizing archaea (AOA) and ammonia oxidizing bacteria\ud
(AOB) and the diversity of nirS-harboring bacteria. Vegetated sediments showed significantly higher\ud
abundances of N-cycling genes than bare sediments. Plant communities dominated by Isoetes generated sediments\ud
with higher redox and NO2\ud
3 concentrations and significantly higher DNT rates than natopotamidsdominated\ud
landscapes. Accordingly, increasing DNT rates were observed along the gradient from low ROL\ud
plants-bare sediments-high ROL plants. Significantly higher abundance of the archaeal amoA gene was\ud
recorded in sediments colonized by high ROL plants unveiling a key biogeochemical role for AOA in coupling\ud
macrophyte landscape and ecosystem denitrification.MVC was supported by a Juan de\ud
la Cierva fellowship from the Spanish Office for Research (MINECO) and\ud
a Beatriu de Pin os from the Catalan Government. This research was\ud
granted by projects DARKNESS CGL2012-32747 (MINECO) to EOC and\ud
AQUAREST (OAPN 212/2010) to EG. EC, EOC and EG are members of\ud
the Environmental Changes Ecology Group (GECA), an Excellence\ud
Research Group (SGRDGR), of the Generalitat de Catalunya (Ref. 2014\ud
SGR 1249. 2014–2017).Peer reviewe