Contribution Of Different Forms Research Articles

Environment or behavior: Which childhood nature experiences predict nature relatedness in early adulthood?

Childhood nature experiences have been identified as critical factors of Nature Relatedness (NR) at the individual level. This exploratory study delved into the distinct contribution of different forms of childhood experiences to NR in early adulthood, focusing on the living environment and actual contact with nature, along with nature education and the influence of people around. NR scores and self-reported experiences of Chinese college students (n = 431) were collected using a questionnaire survey. Objective environmental indicators (normalized difference vegetation index, land cover, and nighttime light) in 13 buffers of different sizes were adopted to precisely depict their historical living environments. Based on the results of bivariate correlations and hierarchical linear regressions, the quantity of natural components in the childhood living environment did not predict long-term NR. Nighttime light and impervious surface at large geographic scales had significant but weak negative correlations with NR. Experiences of actual contact with nature, especially the experiences of interactive behaviors rather than merely visiting natural spaces, are better predictors than the objective environment. The interactive behaviors of observing natural processes and cultivating plants had significantly independent contributions to NR, even when other factors were included in the regression models. Nature education could not replace the role of actual contact with nature. This study implies that an urbanized living environment will not necessarily reduce the level of NR of future generations. Rather than simply increasing the quantity of natural components in urban areas, it is more important to support children’s interactive behaviors with nature.

Teacher collaboration, school innovativeness and innovative teaching in Taiwan: Evidence from TALIS

The significance of teacher collaboration in driving school changes has been widely acknowledged. However, previous studies have rarely delved into the relative contributions of different forms of teacher collaboration. In this study, we aimed to address this gap by identifying two forms of collaboration and examining their effects on school innovativeness and innovative teaching practice using structural equation modeling. Our sample comprised 3,835 teachers of lower secondary schools in Taiwan, drawn from the TALIS 2018 dataset. The findings of our study suggested the differential effects of the two forms of collaboration. "Professional collaboration," characterized by deeper-level engagement, was found to have a more substantial association with both school innovativeness and innovative teaching compared to "exchange and coordination for teaching." Furthermore, our analysis revealed mediation effects in the pathways examined. Specifically, school innovativeness partially mediated the effect of "professional collaboration" and fully mediated the effect of "exchange and coordination for teaching" on innovative teaching.

Isolated But Not Necessarily Lonely

Abstract: Previous research points to social/affiliative needs as playing an important role in orienting people towards conspiratorial thinking. Yet no research to date has compared the relative contribution of different forms of subjective interpersonal isolation to general conspiracist ideation (CI). Four studies ( N = 2,452) compare the associations between three forms of subjective isolation (loneliness, existential isolation, alienation/anomie) and CI. Results from Studies 1–3 indicate that existential isolation and alienation, but not loneliness, independently predict higher CI over and above other relevant predictors. Study 4 found that after controlling for relevant covariates, only anomie predicted CI. Exploratory analyses revealed that unique effects of existential isolation on CI emerged when the breakdown of the leadership subdimension of anomie was excluded from the model. Implications of the four studies are discussed.

Effect of Long-Term Application of Inorganic Fertilizers, Organic Manure, and Lime on Different Forms of Potassium in Soil under Maize-Wheat Cropping System

The field study was undertaken with the major emphasis on potassium fractionation and its contribution in acid alfisol soils as affected by adoption of continuous cropping, fertilization, and manuring under maize-wheat cropping system in same field over 62 years of crop cycles. The experiment consisted of fourteen treatments, replicated thrice times in a randomized block design, out of which nine treatments were selected for the present study. The selected treatments were as follows - control, T2-100% N, T3- FYM, T4-100% NP, T5-100% NPK, T6- 1/2(N+FYM) + P(A-X/2) + K(B-Y/2) (INM), T7-100% NPK + Lime where the lime application in LR once in 4 years, T8-Lime+ FYM+ P(A-X) + K(B-Y), T9-Lime+N. Surface soil (0-15cm) and subsurface soil (16-30 cm) samples were collected after the harvest of wheat in 2017-18 to observe the initial Physico-chemical properties. Different fractions of potassium, viz., water-soluble K, exchangeable K, available K, 1NHNO3K, non-exchangeable K, Lattice K, and Total K were analyzed for the study. There was a significant difference among the different treatments with respect to potassium fractions in 0-15 cm, and 16-30 cm layers. Moreover, K fractions were significantly decreased with increasing depth of soil. Results showed that the percentage contribution of different forms of K with regard to the total K in surface soil and subsurface soil followed as: Lattice K (68.75-78.11%) > Non – Exchangeable K (19.15-25.49%) > Exchangeable K (1.65-2.45%) >Water soluble K (0.18-0.62%). Application of N and P without K caused depletion of soil, water-soluble K, available K, exchangeable K, non-exchangeable K, and lattice K because of continuous omission of potassium content during the all crop growing stages or the simultaneous leaching nature of residual potassium under same field of the experiment. Therefore, the present investigation stresses the vital importance of the inclusion of organic manure and lime in the fertilizer schedule to maintain soil K dynamics over the long run under the maize-wheat cropping system.

Gaze-dependent evidence accumulation predicts multi-alternative risky choice behaviour.

Choices are influenced by gaze allocation during deliberation, so that fixating an alternative longer leads to increased probability of choosing it. Gaze-dependent evidence accumulation provides a parsimonious account of choices, response times and gaze-behaviour in many simple decision scenarios. Here, we test whether this framework can also predict more complex context-dependent patterns of choice in a three-alternative risky choice task, where choices and eye movements were subject to attraction and compromise effects. Choices were best described by a gaze-dependent evidence accumulation model, where subjective values of alternatives are discounted while not fixated. Finally, we performed a systematic search over a large model space, allowing us to evaluate the relative contribution of different forms of gaze-dependence and additional mechanisms previously not considered by gaze-dependent accumulation models. Gaze-dependence remained the most important mechanism, but participants with strong attraction effects employed an additional similarity-dependent inhibition mechanism found in other models of multi-alternative multi-attribute choice.

Fractions of Soil Potassium and their Depthwise Distribution under Long-Term Nutrient Management Practices in Semiarid Alfisols in India

A field experiment was conducted on a long-term experimental plot during two consecutive rabi seasons of 2016-17 and 2017-18 at the college farm, College of Agriculture, Rajendranagar, Hyderabad, PJTSAU. The experimental soil was non-saline, neutral in reaction with sandy loam texture. Different forms of soil potassium were studied with six different nutrient management practices in randomized block design with four replications. The results of pooled data of two years study revealed that significantly higher contents of water soluble potassium (17.77 mg kg-1), exchangeable potassium (568 mg kg-1), nonexchangeable potassium (999 mg kg-1) and Total potassium (1.80%) in surface layer (0-15 cm) at flowering were recorded with integrated application of 50% N through FYM and 50% N through chemical fertilizers and it was on par with treatment applied 100% RDF through chemical fertilisers and significantly superior over other organic nutrient management treatments. A similar trend was observed at all soil depths (15-30, 30-45, 45-60 cm) and all the contents were decreased from flowering to harvest. All potassium forms decreased with increasing the depth except non exchangeable K. All the fractions were found to be significant in surface layer (0-15 cm). The contribution of different forms of soil K to Total K was in the order of non-exchangeable K> exchangeable K> water soluble K and similar trend was observed in all soil layers.

Using stable isotope probing and fluorescence spectroscopy to examine the roles of substrate and soluble microbial products in extracellular polymeric substance formation in activated sludge process

In this study, we used stable isotope-labeled soluble microbial products (SMP) and substrates to explore their assimilation into the formation of new biological products (i.e., extracellular polymeric substances and biomass) in two adjacent sequencing batch reactors. The isotope labeling approach along with fluorescence spectroscopy allowed us to distinguish between refractory and labile portions of SMP constituents as well as their roles in the formation of extracellular polymeric substances (EPS). Comparison of SMP fluorescence and the specific UV absorbance values between the two reactors revealed the presence of humic-like aromatic substances in the non-consumable part of SMP, which can be ultimately released as effluent organic matter. Parallel factor analysis modeling of fluorescence spectra showed that the hydrolysis of EPS contents mostly resulted in humic-like components in SMP rather than protein-like components, which were initially abundant in EPS (>80%). From variations in carbon and nitrogen isotopic contents in EPS and biomass, it was found that carbon-containing substrates were enriched faster than their nitrogenous counterparts. The contributions to new EPS formation reached 87.5% for carbon and 60.5% for nitrogen. Meanwhile, the isotopic tracking of the labeled SMP revealed that only 11.0% and 11.9% of carbon and 13.3% and 11.6% of nitrogen from the influent SMP were finally assimilated into EPS and biomass, respectively. In contrast, the isotopic enrichment in SMP was higher (~50%) than that of EPS and biomass, indicating the low bioavailability and refractory nature of the feed SMP. This study proposed a promising approach for estimating the relative contributions of different forms of labile substrate and SMP to the formation of EPS in activated sludge processes. This approach could be suggested as a versatile method for establishing the kinetics, substrate element flow, mass balance on organic substrates and nutrients, as well as for tracking the consumption and uptake pathways of hazardous materials.

Release characteristics of inorganic nitrogen in different water layers and its impact on overlying water from Liaohe River, China.

Migration and release of sediment pollutants has become one of the important causes of water pollution, but the contribution of different forms of nitrogen in different water layers to the water quality of the overlying water is unclear. In this study, the main stream of Liaohe River with heavy nitrogen pollution was taken as an example. The static simulation method and related analysis techniques were used to explore the release characteristics of different forms of inorganic nitrogen and its effect on TN and Chla in overlying water from the different water layers. The results showed that the release rates of TN, NH4+-N and NO3--N from upstream, midstream and downstream sections were different, but the release characteristics of them in different water layers were the same basically. Generally, the inorganic nitrogen in the pore water of the sediment was released to the water body rapidly in the early 0-8 days. The contribution rate of NH4+-N and NO3--N to the change of TNo was 76.85% for the upstream section, and the contribution rate of NO3--N to the change of TNo was 65.02% for the midstream section. NH4+-N and NO3--N in the different water layers from downstream did not showed a significant correlation with TN of overlying water. NO3--N in sediments was the main contributor of TN and Chla changes in the overlying water and its content can reflect the nitrogen pollution trend of the water body to a certain extent. When the water retention time was 4-16 days, the TLI in the water body was relatively high. After effective control of exogenous pollution, the release of endogenous nutrients in Liaohe River should be paid more attention.

Free Choline, but Not Phosphatidylcholine, Elevates Circulating Trimethylamine-N-oxide and This Response Is Modified by the Gut Microbiota Composition in Healthy Men

Abstract Objectives Trimethylamine-N-oxide (TMAO), a choline-derived gut microbiota-dependent metabolite, is a newly recognized risk marker for cardiovascular disease. However, the contributions of different forms of choline and gut microbiota composition on TMAO production are largely unknown. The objectives of this study were to: 1) compare acute TMAO response to meals containing free choline (choline bitartrate) versus fat-soluble choline (phosphatidylcholine) and 2) to determine the effects of gut microbiota composition on TMAO response. Methods In a controlled, double-blinded, cross-over study, healthy men (n = 37) were provided meals containing (i) 600 mg choline as choline bitartrate (free choline); (ii) 600 mg choline as phosphatidylcholine; or (iii) no choline control in a random order. Blood and urine samples were collected at baseline and throughout the 6-h study period; a one-time stool sample was collected at baseline. Results Compared to no choline and phosphatidylcholine, free choline yielded 295% higher plasma TMAO (P = 0.002) and 250% higher urinary TMAO (P = 0.01), with no difference in TMAO response between phosphatidylcholine and no choline. High-TMAO producers (those with ≥40% increase in urinary TMAO response to free choline) had significantly different beta-diversity measures (unweighted UniFrac; PERMANOVA P = 0.01) compared to low-TMAO producers (those with <40% increase in TMAO response) but showed no difference in alpha-diversity. Analysis of Composition of Microbiomes (ANCOM) revealed that high-TMAO producers had more abundant lineages of Clostridium from Ruminococcaceae and Lachnospiraceae (in phylum Firmicutes) compared to low-TMAO producers (P < 0.05 with the strength of the ANCOM test W = 11 and W = 8, respectively). Conclusions Given that the majority of choline in food is in the form of phosphatidylcholine, the absence of TMAO elevation with phosphatidylcholine counters arguments that dietary choline should be avoided for TMAO-producing characteristics. Further, development of individualized dietary recommendations based on the gut microbiota composition may be a more appropriate strategy to reduce risk of cardiovascular disease. Funding Sources This research was supported by the Utah Agricultural Experiment Station Seed Grants Program.

Between Apprenticeship and Skill: Acquiring Knowledge outside the Academy in Early Modern England

ArgumentApprenticeship was probably the largest mode of organized learning in early modern European societies, and artisan practitioners commonly began as apprentices. Yet little is known about how youths actually gained skills. I develop a model of vocational pedagogy that accounts for the characteristics of apprenticeship and use a range of legal and autobiographical sources to examine the contribution of different forms of training in England. Apprenticeship emerges as a relatively narrow channel, in which the master’s contribution to training was weakly defined and executed conservatively. The creation of complementary channels of formal instruction was constrained by cost and coordination problems. When we consider a range of British youths who obtained advanced skills as artisan practitioners (and engaged in invention or pursued natural philosophical interests), we see the importance of individual agency over institutional structures. For these youths, training could involve rejecting apprenticeship, engaging in periods of advanced study, including time in multiple workshops after the end of apprenticeship, and parallel campaigns to access scarce books and communities of scholarship.

A mid-century ecological forecast with partitioned uncertainty predicts increases in loblolly pine forest productivity.

Ecological forecasting of forest productivity involves integrating observations into a process-based model and propagating the dominant components of uncertainty to generate probability distributions for future states and fluxes. Here, we develop a forecast for the biomass change in loblolly pine (Pinus taeda) forests of the southeastern United States and evaluate the relative contribution of different forms of uncertainty to the total forecast uncertainty. Specifically, we assimilated observations of carbon and flux stocks and fluxes from sites across the region, including global change experiments, into a forest ecosystem model to calibrate the parameter distributions and estimate the process uncertainty (i.e., model structure uncertainty revealed in the residuals of the calibration). Using this calibration, we forecasted the change in biomass within each 12-digit Hydrologic (H12) unit across the native range of loblolly pine between 2010 and 2055 under the Representative Concentration Pathway 8.5 scenario. Averaged across the region, productivity is predicted to increase by a mean of 31% between 2010 and 2055 with an average forecast 95% quantile interval of ±15 percentage units. The largest increases were predicted in cooler locations, corresponding to the largest projected changes in temperature. The forecasted mean change varied considerably among the H12 units (3-80% productivity increase), but only units in the warmest and driest extents of the loblolly pine range had forecast distributions with probabilities of a decline in productivity that exceeded 5%. By isolating the individual components of the forecast uncertainty, we found that ecosystem model process uncertainty made the largest individual contribution. Ecosystem model parameter and climate model uncertainty had similar contributions to the overall forecast uncertainty, but with differing spatial patterns across the study region. The probabilistic framework developed here could be modified to include additional sources of uncertainty, including changes due to fire, insects, and pests: processes that would result in lower productivity changes than forecasted here. Overall, this study presents an ecological forecast at the ecosystem management scale so that land managers can explicitly account for uncertainty in decision analysis. Furthermore, it highlights that future work should focus on quantifying, propagating, and reducing ecosystem model process uncertainty.

Master role conversion between diffusion and seepage on coalbed methane production: Implications for adjusting suction pressure on extraction borehole

Diffusion and seepage control coalbed methane (CBM) production jointly, and their controlling roles differ significantly in different stages of extraction. Although many CBM models have well been established, but these models cannot better quantify the controlling degree of diffusion and seepage on CBM production at a certain moment and determine when the master role between them happens to convert. In this paper, the conversion between different forms of methane and the underlying controlling mechanisms were analyzed firstly. According to contributions of different forms of methane to total production, a theoretical master role conversion model between diffusion and seepage on CBM production was established. And the theoretical model can better distribute the contribution degree of in-situ adsorbed methane to the total CBM production. The model was employed to analyze the time nodes when master role conversion occurs with different initial permeabilities and diffusion coefficients. Results show that higher coal permeability/diffusion coefficient results in earlier the conversion time node. The same conclusion also applies to the time node when the diffusion effect almost completely controls the CBM production. Besides, the change curves of daily methane production indicate that the production is primarily controlled by seepage in early stage of extraction, while controlled by diffusion in later stage. Methane extraction efficiency and concentration are closely related to drainage pressure. For ensuring underground mining safety, constant low-pressure extraction strategy is employed frequently to insure the extraction efficiency, which, however, leads to low methane concentration and utilization rate. This paper proposes a new extraction pressure regulating method, namely, time-based pressure regulating method that selected time node in accordance with the master role conversion theory. The simulation results prove that the new method can not only ensure extraction efficiency, but also guarantee extraction concentration as well as utilization, thus reducing the natural emissions of methane and amount of greenhouse gas.

Different silicon forms sinalize an input of urbanized river and indicate the presence of phytoplankton with silicon structures in the tropical coastal area of Recife (PE-Brazil)

Abstract The urbanized areas mark its presence in the hydrological systems with some biogeochemical signs including silicon inputs. Natural influence of leaching and erosion is done by silicate contribution and sometimes, the agriculturally soil contains microphytoliths and contributes with biogenic silica. Once in the hydrological system, the silicon can integrate the biogeochemical cycles showing a balance or not between inorganic and biological forms that reveals a tendency of processes that occur in each sector of the estuarine-marine interface. This study aims to evaluate the impact of a heavily polluted/urbanized river, whose input can be evidenced by the contribution of different forms of silicon that can evidence the terrestrial contribution, erosion process, the presence of phytoplankton species with siliceous structures, mainly associated to diatoms and also, to study the river plume spreading on the coastal area by undertaking silicon profiles in the region adjacent to the river mouth. The coastal region of Recife is under influence of fluvial inputs from Capibaribe and Beberibe rivers verified by observed low salinity (min. 33.93). The distribution of silicon forms showed sectorial variation, and the maximum values were dissimilar. Dissolved silicate reached 14.40 µmol L-1, lithogenic silicon (LSi) maximum of 25.76 µmol L-1 and biogenic silica (BSi) reaching 7.39 µmol L-1 near the river mouth toward the sea, evidencing the river influence coming from the west, achieving the port barrier at the end and propagating in the sea toward northeast. Due to higher nutrient availability in the stations nearest to the coast, primary production was encouraged with evidencing by high values of chlorophyll-a associated to silicate (r=0.71) and to BSi (r=0.44). In the stations more distant to the coast, the forms of silicon showed very low concentrations and BSi/Chlorophyll-a showed negative correlation associated with chlorophyll-a concentrations evidencing the participation of non-silicon actors in the primary production in medium depth in oligotrophic tropical waters.

The importance of pKa in an analysis of the interaction of compounds with DNA

pKa of a compound is crucial for determining the contributions of different forms of it towards overall binding with DNA. Hence it is important to use correct pKa values in DNA interaction studies. This study takes a look at the importance of pKa values to realize binding of compounds with DNA. Since pKa of a compound determined in the presence of DNA is quite different from that determined in its absence hence, presence of different forms of a compound during interaction with DNA is different from that realized if the determination of pKa is done in normal aqueous solution in absence of DNA. Hence, calculations determining contributions of different forms of a compound interacting with DNA are affected accordingly. Two simple analogues of anthracyclines, alizarin and purpurin, were used to investigate the influence DNA has on pKa values. Indeed, they were different in presence of DNA than when determined in normal aqueous solution. pKa1 for alizarin and purpurin determined in the absence and presence of calf thymus DNA were used in equations that determine contributions of two forms (neutral and anionic) towards overall binding with DNA. The study concludes that correct pKa values, determined correctly i.e. under appropriate conditions, must be used for DNA binding experiments to evaluate contributions of individual forms.

Influence of military sexual assault and other military stressors on substance use disorder and PTS symptomology in female military veterans

Servicewomen exposed to traumatic stressors over the course of their military service are at increased risk of developing symptoms of substance use disorder (SUD) and posttraumatic stress (PTS). They are also at risk for exposure to military sexual assault (MSA), which is also associated with SUD and PTS symptomology. Research is unclear about the incremental contributions of different forms of traumatic stressors on co-occurring SUD and PTS symptomology. In this study we examined the independent and combined effects of MSA and other military stressors on SUD and PTS symptomology in a sample of female veterans (N=407). Results indicate that MSA and other military stressors exhibit incremental effects on SUD and PTS symptomology. Results further suggest that women exposed to both MSA and other military stressors are at increased risk for developing co-occurring SUD and PTSD. These findings extend previous research on comorbid SUD and PTSD, highlighting the cumulative effects of traumatic stressors on posttraumatic psychopathology, and have implications for future research and clinical practice with female veterans.

Carbon, nitrogen and phosphorus stoichiometry of rivers in the light of Redfield ratio

Abstract. A. Redfield entered the history of hydroecology due to the discovery of a unique stoichiometric ratio of Carbon, Nitrogen and Phosphorus – 106: 16: 1 – in the marine plankton, which it was later named after the author – the Redfield Ratio. Furthermore, A. Redfield established, that the stoichiometric ratio of Carbon, Nitrogen and Phosphorus in seawater is supported on the average level and it is 1017 : 15 : 1. On the basis of established stoichiometric ratios A. Redfield came to the conclusion that exactly Nitrogen is a limiting factor in the marine environment, because the ratio of its average statistical stoichiometric availability in seawater turned out lower than the average stoichiometric utilization of plankton. Also the merit of A. Redfield is the was established by him the carbon and nitrogen forms, which make the greatest contribution to the pool of these elements are available for plankton. After Redfield the studies by the CNP-stoichiometry of water and plankton in marine and ocean ecosystems were carried out by a number of researchers. However, the CNP-stoichiometry of rivers water fell out of the field of view of hydroecologists. The authors of this publication tried to fill this gap. The purpose of the studies was to establish the peculiarities of CNP-stoichiometry of river ecosystems in comparison with marine ecosystems and it determine the contribution of different forms of carbon and nitrogen to the pool of these elements which available for plankton in river water. The research was conducted during the summer low water period (2014) at the at monitoring stations of watershed of the three rivers of the Carpathian region within the Chernivtsi region. It is Dniester, Prut and Siret. Water samples were taken by a bathometer at 16 sites (near 8 forest and 8 meadow floodplains) of each of the 15 monitoring stations. Under laboratory conditions, the nitrate content was determined by the nitrate meter (H-401). Carbonates and hydrogen carbonates was determined by titrimetrically method. Phosphates, ammonia and nitrites was determined by photocolorimetrically method. Like Redfield, the stoichiometric availability of Сarbon and Nitrogen in river water was estimated as the ratio of the molar concentrations of the corresponding elements to the molar Phosphorus concentration. For the first time the features of CNP stoichiometry of the rivers were installed in comparison with the marine stoichiometry. The stoichiometric ratio of total carbon, nitrogen and phosphorus in river water of the Carpathian region is 938C: 59N: 1P and the ratios of their stoichiometric availability to stoichiometric utilization by plankton is 8,9C : 3,7N : 1P. It was shown that stoichiometric availability of energetically favorable for the assimilation by plankton by forms of carbon and nitrogen – СО2 и NH4+ – in the rivers water is greatly reduced, and do not cover the necessary level of stoichiometric utilization of these elements by plankton. It is proved that the greatest contribution in the river water to the pool of stoichiometric available of carbon and nitrogen contributes HCO3-, а азота – NО3- in accordance. It was found that the main limiting factor of growth of and development of plankton in rivers of the Carpathian region appears phosphorus whose balanced share in CNP ratio is an order of magnitude lower than that it need for the utilization by plankton.

L’émergence de dynamiques coopératives : l’exemple d’un réseau d’entreprises créatives co-localisées. Une approche par l’économie des proximités

L’objectif de cet article est d’analyser les conditions de l’emergence des collaborations entre un ensemble de firmes co-localisees appartenant aux industries culturelles et creatives. En nous appuyant sur l’economie des proximites, nous confirmons, a partir d’une analyse exhaustive des cooperations developpees entre 50 entreprises creatives regroupees au sein d’un meme bâtiment, que la proximite geographique ne se convertit en cooperation qu’a la condition qu’elle s’accompagne d’autres formes de proximite dites socio-economiques. Trois resultats principaux se degagent de notre travail : (1) la necessite de personnalites Gatekeeper chargees de faire le lien entre les acteurs, (2) le role des dispositifs specifiques de mise en connexion des acteurs (configuration des lieux, routines, protocoles…) dans le developpement des collaborations et (3) l’interet d’identifier plus formellement une proximite de valeurs au sein des categories existantes de proximites socio-economiques.

Habitat preference and flowering-time variation contribute to reproductive isolation between diploid and autotetraploid Anacamptis pyramidalis.

Tetraploid lineages are typically reproductively isolated from their diploid ancestors by post-zygotic isolation via triploid sterility. Nevertheless, polyploids often also exhibit ecological divergence that could contribute to reproductive isolation from diploid ancestors. In this study, we disentangled the contribution of different forms of reproductive isolation between sympatric diploid and autotetraploid individuals of the food-deceptive orchid Anacamptis pyramidalis by quantifying the strength of seven reproductive barriers: three prepollination, one post-pollination prezygotic and three post-zygotic. The overall reproductive isolation between the two cytotypes was found very high, with a preponderant contribution of two prepollination barriers, that is phenological and microhabitat differences. Although the contribution of post-zygotic isolation (triploid sterility) is confirmed in our study, these results highlight that prepollination isolation, not necessarily involving pollinator preference, can represent a strong component of reproductive isolation between different cytotypes. Thus, in the context of polyploidy as quantum speciation, that generates reproductive isolation via triploid sterility, ecological divergence can strengthen the reproductive isolation between cytotypes, reducing the waste of gametes in low fitness interploidy crosses and thus favouring the initial establishment of the polyploid lineage. Under this light, speciation by polyploidy involves ecological processes and should not be strictly considered as a nonecological form of speciation.

Abstract B48: The effects of different types of hypoxia on tumor progression in breast cancer

Abstract Hypoxia, the state of low oxygen conditions, occurs frequently in solid tumors and is a poor prognostic factor. The expression of Hif-1α,the main mediator of the hypoxic response pathway, and the subsequent up-regulation of its target genes have been implicated in tumor growth, invasion, angiogenesis, therapy resistance and metastasis. There are two forms of hypoxia present in a growing tumor: chronic hypoxia (caused by limitations in oxygen diffusion from abnormal tumor vasculature) and intermittent hypoxia (caused by the aberrant, repeated and temporary closing and re-opening of blood vessels, leading to fluctuations in oxygen supply). This study investigates the phenotypes endowed by different forms of hypoxia that mediate metastatic potential in a syngeneic mouse model of breast cancer. By exposing murine breast cancer cells to 9 days of 20% O2 (normoxia), 1% O2 (chronic hypoxia) or alternating 24 hour cycles in 20% O2 and 1% O2 (intermittent hypoxia), we observe that intermittent hypoxia produces tumor cells with greater metastatic potential. These treatments produce no difference in primary tumor growth when orthotopically injected into the mammary fat pad of female C57Bl/6 mice. However, intermittent hypoxia-treated cells give rise to a greater number of and larger lung metastases when injected intravenously via the tail-vein of female C57Bl/6 mice. Intermittent hypoxia, but not chronic hypoxia, up-regulated the expression of genes that predict lung metastasis in breast cancer, endowed cells with an enhanced ability for anchorage-independent growth and produced greater clonal diversity. Furthermore, intermittent hypoxia also caused a switch to glycolysis in cells and induced a pro-tumorigenic, immunosuppressive secretory profile in vitro. Finally, intermittent hypoxia up-regulated the expression of mammary stem cell genes, increased expression of stem cell marker Sca-1 as well as CD14, and generated tumor-initiating cells at a higher frequency as evidenced by in vivo limiting dilution assays. This work demonstrates that intermittent hypoxia enhances metastatic seeding and outgrowth by priming cells intrinsically to metastasize, while activating co-operating factors that act extrinsically to form a permissive, immunosuppressive microenvironment. By delineating the contributions of different forms of hypoxia to metastasis, critical molecular mediators can be identified in aid of the development of efficacious therapies that could inhibit, prevent or cure metastatic disease. Citation Format: Anna Chen, Jaclyn Sceneay, Nathan Gödde, Erik Thompson, Patrick Humbert, Andreas Möller. The effects of different types of hypoxia on tumor progression in breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Metastasis; 2015 Nov 30-Dec 3; Austin, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(7 Suppl):Abstract nr B48.

Temporal and spatial variations of phosphorus loading and the forms, compositions and contributions in inlet river of Lake Dianchi

研究了2013年滇池主要入湖河流总磷（TP）及各形态磷浓度的时空变化与入湖负荷特征，并探讨了不同形态磷的入湖负荷贡献.结果表明：（1）滇池河流入湖TP浓度在0.11～1.93 mg/L之间，以溶解性无机磷（DIP）和颗粒态磷（PP）为主，溶解性有机磷（DOP）浓度较低；（2）滇池河流入湖磷负荷总量为280.51 t/a，绝大多数河流主要以DIP形态入湖，平均贡献率为43.48%；PP形态入湖负荷次之，平均贡献率为31.64%；DOP入湖负荷较低，平均贡献率为24.88%；（3） DIP入湖负荷贡献率较高值出现在3、4和11月的枯水期，平均入湖负荷贡献率达到55.30%；PP入湖负荷贡献率较高值出现在1和7月，平均入湖负荷贡献率为56.14%；DOP入湖负荷贡献率月变化差异较小，最高值出现在12月，贡献率为21.85%；（4）研究滇池入湖河流污染负荷不仅要考虑溶解态无机磷的贡献，而且需要重视PP和DOP负荷，控制滇池入湖河流污染负荷需要考虑不同河流不同形态磷负荷组成及月变化差异特征，有针对性地采取相应措施.;The temporal and spatial changes of total phosphorus(TP) and various forms of phosphorus concentration, and the inlet load characteristics were studied in major inlet river of Lake Dianchi. At the same time, the contribution of different forms of phosphorus from the inlet load was discussed. The results showed:(1) The TP concentrations of the inlet river into Lake Dianchi were between 0.11-1.93 mg/L, and the particulate phosphorus(PP) and dissolved inorganic phosphorus(DIP) forms were the main part. (2) The TP loading of the inlet rivers of Lake Dianchi was 280.51 t/a, and DIP was the main form in most rivers into the lake with an average contribution of 43.48%. PP form into the lake load followed with an average contribution of 31.64%. DOP form into the lake load was relatively low with an average contribution of 24.88%. (3) DIP load into the lake with the higher contribution value appeared in dry season (March, April and November), which the average contribution rate reached to 55.30%. Higher values of PP forms into the lake load occurred in January and July, with the average contribution of 56.14%. Change of the DOP load into the lake was relatively low, with the highest value appeared in December and its contribution was 21.85%. (4) The river pollution load into Lake Dianchi not only needs to be considered the contribution of the dissolved inorganic phosphorus into the lake, but also to be paid an attention on the dissolved organic phosphorus and particulate phosphorus loading. During the process of comprehensive improvement of the inlet river loading into the lake, we should take corresponding measures according to different forms of phosphorus loading in different rivers and in different months in order to attempt getting a better effect.