| 1. |
- Fu, Hong, et al.
(författare)
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Energetic Asymmetry Connected with Energy Flow Changes in Response to Eutrophication : A Study of Multiple Fish Species in Subtropical Shallow Lakes
- 2019
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Ingår i: Polish Journal of Ecology. - 1505-2249. ; 67:4, s. 305-315
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Tidskriftsartikel (refereegranskat)abstract
- Energy flow is a central characteristic in all ecosystems, and it has attracted considerable scientific attention due to its significant effects on the stability of food webs. Lake ecosystems that undergo regime shifts (clear water phase, phytoplankton dominated changed into turbid water, macrophytes dominated or vice versa) are characterized by a series of transformation in trophic structure. Although previous studies have mainly focused on the causes and consequences of regime shifts in shallow lakes, studies about responses of energy flow changes to regime shifts is far from complete. In this paper, we estimated trophic position and benthivory (i.e. degree of benthivory) of seventeen fish species from seven shallow lakes. Our data show that the trophic position and benthivory of fish species in clear water phase are significantly higher than in turbid water. This finding might help spark some ideas for subtropical lake eutrophication treatment.
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| 2. |
- Sampson, Joshua N., et al.
(författare)
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Analysis of Heritability and Shared Heritability Based on Genome-Wide Association Studies for 13 Cancer Types
- 2015
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 0027-8874 .- 1460-2105. ; 107:12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites. Methods: Between 2007 and 2014, the US National Cancer Institute has generated data from genome-wide association studies (GWAS) for 49 492 cancer case patients and 34 131 control patients. We apply novel mixed model methodology (GCTA) to this GWAS data to estimate the heritability of individual cancers, as well as the proportion of heritability attributable to cigarette smoking in smoking-related cancers, and the genetic correlation between pairs of cancers. Results: GWAS heritability was statistically significant at nearly all sites, with the estimates of array-based heritability, h(l)(2), on the liability threshold (LT) scale ranging from 0.05 to 0.38. Estimating the combined heritability of multiple smoking characteristics, we calculate that at least 24% (95% confidence interval [CI] = 14% to 37%) and 7% (95% CI = 4% to 11%) of the heritability for lung and bladder cancer, respectively, can be attributed to genetic determinants of smoking. Most pairs of cancers studied did not show evidence of strong genetic correlation. We found only four pairs of cancers with marginally statistically significant correlations, specifically kidney and testes (rho = 0.73, SE = 0.28), diffuse large B-cell lymphoma (DLBCL) and pediatric osteosarcoma (rho = 0.53, SE = 0.21), DLBCL and chronic lymphocytic leukemia (CLL) (rho = 0.51, SE = 0.18), and bladder and lung (rho = 0.35, SE = 0.14). Correlation analysis also indicates that the genetic architecture of lung cancer differs between a smoking population of European ancestry and a nonsmoking Asian population, allowing for the possibility that the genetic etiology for the same disease can vary by population and environmental exposures. Conclusion: Our results provide important insights into the genetic architecture of cancers and suggest new avenues for investigation.
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| 3. |
- He, Huan
(författare)
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A multi-omics approach to uncover estrogen receptor (ER) and activator protein 1 (AP-1) signaling networks in breast cancer
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Estrogen receptor (ER) binds to DNA indirectly through other transcription factors (e.g. AP-1) to modulate gene expression, which is a tethering mechanism. The ER/AP-1 crosstalk plays an important role in tamoxifen therapy resistance. However, the overlap in DNA binding profiles of ER and AP-1 transcription factors at genome-wide level has not been described. Moreover, AP-1 plays a pivotal role in various cellular processes in breast cancer. The transcriptional activity of AP-1 is controlled by coregulators, thereby regulating the expression of specific genes. Understanding protein-protein interactions is fundamental to the mechanism of AP-1 signaling. In addition, ERα is one of the key biomarkers for diagnosis and endocrine therapy of breast cancer. However, ERα status is not considered to be a perfect marker for responsiveness to anti-estrogens. It has been shown that ERβ may act as a tumor suppressor and could be a therapeutic target for breast cancer, however the functions of ERβ in this setting remain to be further explored. The use of multi-functional genomic technologies to identify cistrome, transcriptome and proteome of ER or AP-1 has resulted in comprehensive deciphering of the role of the ER and AP-1 in breast cancer, which also provides information for developing novel therapeutic strategies for breast cancer. In Paper I, we investigated the genome-wide assessment of c-Jun, a potent member of AP-1 family, and ERα cistrome and transcriptome in ERα-positive breast cancer cells. Our findings demonstrate the genome-wide co-localization of ERα and c-Jun binding regions and suggest that ERα tethering to AP-1 is a global mechanism for gene transcription regulated by ERα. In addition, the results confirm that the sensitivity of ERα-positive breast cancer cells to tamoxifen therapy is reduced by c-Jun overexpression. Moreover, it is shown that expression of transforming growth factor β induced (TGFBI) protein is associated with poor outcomes of ERα-positive breast cancer patients receiving endocrine therapy and thus as a candidate gene that may cause tamoxifen resistance through ERα and AP-1 crosstalk. In Paper II, we elucidated the first Fra-1 associated interactome in triple-negative breast cancer (TNBC) cells using Rapid Immunoprecipitation Mass Spectrometry of Endogenous proteins (RIME) approach, showing that the most enriched Fra-1 interacting protein was DDX5. The cistrome and transcriptome of DDX5 extensively overlapped with that of Fra-1, which is highly associated with the TNBC cell growth. Furthermore, we found that DDX5 acts as a transcriptional coactivator for Fra-1, enhancing Fra-1-dependent TNBC cell proliferation through increasing the transcriptional activity of Fra-1. We also showed that higher expression level of DDX5 protein was detected in triple-negative basal-like tumors compared with that in non-basal-like ones. In addition, the direct target gene set of DDX5 can predict poor clinical outcome of breast cancer patients. In Paper III, we generated a novel breast cancer cell model with overexpression of ERβ in the absence of ERα. We used CRISPR/Cas9 system to knock out ERα in MCF7 breast cancer cells with stable Tet-Off-inducible ERβ expression. We found that only ERβ-expressing MCF7 cells displayed a significant reduction in cell proliferation in response to E2 compared with vehicle, conversely, only ERα-expressing MCF7 cells displayed an increased cell proliferation upon E2 treatment. The RNA-seq results indicated that ERβ could modulate specific gene expression profile different from that of ERα. Furthermore, functional enrichment analysis showed that the two ER isoforms regulate cell proliferation in opposite direction; ERβ is significantly involved in the biological process “negative regulation of cell proliferation”. In conclusion, the studies presented in the thesis contribute to comprehensive understanding of the mechanism of ER and AP-1 signaling in breast cancer. We characterized two molecules, TGFBI and DDX5, in breast cancer, suggesting that they could be the candidates of therapeutic targets. We also provided evidences that ERα and ERβ have opposite effects on E2-dependent breast cancer cell proliferation by regulating distinct gene sets.
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| 4. |
- Huang, Yajun, et al.
(författare)
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Flame-retardant polyvinyl alcohol/cellulose nanofibers hybrid carbon aerogel by freeze drying with ultra-low phosphorus
- 2019
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Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332. ; 497
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Tidskriftsartikel (refereegranskat)abstract
- Polyvinyl alcohol/cellulose nanofibers hybrid aerogel was prepared under freeze drying method. To improve the aerogels' anti-combustion performance, 0.8 wt% microencapsulated ammonium polyphosphate (MCAPP) was loaded as the flame retardant. Aerogels with extremely low density (~0.06 g/cm3) and excellent mechanical performance (Young's modulus: 1.045 MPa) can be obtained. The resulted aerogel also exhibit considerable thermal insulation ability (thermal conductivity: ~0.04 W/m·K). Experimental results indicate that the value of limiting oxygen index increases from 19.5% to 37.5% when loading 0.8 wt% MCAPP. Accordingly, the aerogels' peak heat release rate decreased significantly from 222.44 to 107.84 kW/m2. The char residue rises when introducing MCAPP and the char's integrity improves a lot after combustion. The fire performance index and fire growth index increases and falls respectively, indicating improved anti-combustion performance. X-ray photoelectron spectroscopy results show C[dbnd]O bonds would be increased for the esterification of phosphoric acid from MCAPP. In addition, the production of carbonate can be prohibited while combustion when loading MCAPP.
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| 5. |
- Li, Fang, et al.
(författare)
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Lie Detection Using fNIRS Monitoring of Inhibition-Related Brain Regions Discriminates Infrequent but not Frequent Liars
- 2018
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Ingår i: Frontiers in Human Neuroscience. - : Frontiers Media S.A.. - 1662-5161. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Functional near-infrared spectroscopy (fNIRS) was used to test whether monitoring inhibition-related brain regions is a feasible method for detecting both infrequent liars and frequent liars. Thirty-two participants were divided into two groups: the deceptive group (liars) and the non-deceptive group (ND group, innocents). All the participants were required to undergo a simulated interrogation by a computer. The participants from the deceptive group were instructed to tell a mix of lies and truths and those of the ND group were instructed always to tell the truth. Based on the number of deceptions, the participants of the deceptive group were further divided into a infrequently deceptive group (IFD group, infrequent liars) and a frequently deceptive group (FD group, frequent liars). The infrequent liars exhibited greater neural activities than the frequent liars and the innocents in the left middle frontal gyrus (MFG) when performing the deception detection tasks. While performing deception detection tasks, infrequent liars showed significantly greater neural activation in the left MFG than the baseline, but frequent liars and innocents did not exhibit this pattern of neural activation in any area of inhibition-related brain regions. The results of individual analysis showed an acceptable accuracy of detecting infrequent liars, but an unacceptable accuracy of detecting frequent liars. These results suggest that using fNIRS monitoring of inhibition-related brain regions is feasible for detecting infrequent liars, for whom deception may be more effortful and therefore more physiologically marked, but not frequent liars.
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| 6. |
- Li, Zhongqiang, et al.
(författare)
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Climate warming and heat waves affect reproductive strategies and interactions between submerged macrophytes
- 2017
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013. ; 23:1, s. 108-116
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Tidskriftsartikel (refereegranskat)abstract
- Extreme climatic events, such as heat waves, are predicted to increase in frequency and intensity during the next hundred years, which may accelerate shifts in hydrological regimes and submerged macrophyte composition in freshwater ecosystems. Since macrophytes are profound components of aquatic systems, predicting their response to extreme climatic events is crucial for implementation of climate change adaptation strategies. We therefore performed an experiment in 24 outdoor enclosures (400 L) separating the impact of a 4 °C increase in mean temperature with the same increase, that is the same total amount of energy input, but resembling a climate scenario with extreme variability, oscillating between 0 °C and 8 °C above present conditions. We show that at the moderate nutrient conditions provided in our study, neither an increase in mean temperature nor heat waves lead to a shift from a plant-dominated to an algal-dominated system. Instead, we show that species-specific responses to climate change among submerged macrophytes may critically influence species composition and thereby ecosystem functioning. Our results also imply that more fluctuating temperatures affect the number of flowers produced per plant leading to less sexual reproduction. Our findings therefore suggest that predicted alterations in climate regimes may influence both plant interactions and reproductive strategies, which have the potential to inflict changes in biodiversity, community structure and ecosystem functioning.
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| 7. |
- Zhang, Huan, et al.
(författare)
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Life-history traits buffer against heat wave effects on predator-prey dynamics in zooplankton
- 2018
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Ingår i: Global Change Biology. - : WILEY. - 1354-1013 .- 1365-2486. ; 24:10, s. 4747-4757
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Tidskriftsartikel (refereegranskat)abstract
- In addition to an increase in mean temperature, extreme climatic events, such as heat waves, are predicted to increase in frequency and intensity with climate change, which are likely to affect organism interactions, seasonal succession, and resting stage recruitment patterns in terrestrial as well as in aquatic ecosystems. For example, freshwater zooplankton with different life-history strategies, such as sexual or parthenogenetic reproduction, may respond differently to increased mean temperatures and rapid temperature fluctuations. Therefore, we conducted a long-term (18months) mesocosm experiment where we evaluated the effects of increased mean temperature (4 degrees C) and an identical energy input but delivered through temperature fluctuations, i.e., as heat waves. We show that different rotifer prey species have specific temperature requirements and use limited and species-specific temperature windows for recruiting from the sediment. On the contrary, co-occurring predatory cyclopoid copepods recruit from adult or subadult resting stages and are therefore able to respond to short-term temperature fluctuations. Hence, these different life-history strategies affect the interactions between cyclopoid copepods and rotifers by reducing the risk of a temporal mismatch in predator-prey dynamics in a climate change scenario. Thus, we conclude that predatory cyclopoid copepods with long generation time are likely to benefit from heat waves since they rapidly wake up even at short temperature elevations and thereby suppress fast reproducing prey populations, such as rotifers. In a broader perspective, our findings suggest that differences in life-history traits will affect predator-prey interactions, and thereby alter community dynamics, in a future climate change scenario.
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