Integrin αvβ6 has emerged as a potential novel target for anticancer and plays a major role in promoting malignant tumor progression. Recent studies indicate that integrin αvβ6 occurs in many cancers. However, whether and how αvβ6 is regulated by genetic and epigenetic mechanisms in breast cancer remain unknown. In the present study, two different short hairpin RNAs (shRNAs) targeting the β6 gene were designed and constructed into pSUPER, respectively, which were transfected into the MCF-7 human breast adenocarcinoma cell line. The β6-shRNA stably transfected cells were successfully established, and significant lower levels of αvβ6 mRNA and protein expression were confirmed. Furthermore, inhibition of integrin αvβ6 markedly downregulated the expression of matrix metalloproteinase-9 (MMP-9), matrix metalloproteinase-3 (MMP-3) and urokinase plasminogen activator (uPA) in tumor conditioned medium. Furthermore, β6-shRNA-mediated silencing of the αvβ6 gene obviously decreased the expression of ERK1/2. In particular, supression of integrin αvβ6 caused significant downregulation of the degradation of basement membrane type IV collagen secretion via modulation of the plasminogen activation cascade. Our results thus indicate that αvβ6 plays a fundamental role in promoting invasion and growth of breast adenocarcinoma cells. Taken together, this study revealed that targeting of the β6 gene by RNA interference (RNAi) could efficiently downregulate αvβ6 expression and suppress the ERK1/2-dependent extracellular matrix degradation in vitro, which is dependent upon inactivation of the mitogen-Activated protein kinase (MAPK) pathway. These findings may offer a useful therapeutic approach to block invasion and migration of breast cancer cells.

The ecological dynamics of co-flowering communities are largely mediated by pollinators. However, current understanding of pollinator-mediated interactions primarily relies on how co-flowering plants influence attraction of shared pollinators, and much less is known about plant–plant interactions that occur via heterospecific pollen (HP) transfer. Invaded communities in particular can be highly affected by the transfer of alien pollen, but the strength, drivers and fitness consequences of these interactions at a community scale are not well understood. Here we analyse HP transfer networks in nine coastal communities in the Yucatan Mexico that vary in the relative abundance of invasive flowers to evaluate how HP donation and receipt varies between native and alien plants. We further evaluate whether HP donation and receipt are mediated by floral traits (e.g. display, flower size) or pollinator visitation rate. Finally, we evaluated whether post-pollination success (proportion of pollen tubes produced) was affected by alien HP receipt and whether the effect varied between native and alien recipients. HP transfer networks exhibit relatively high connectance (c. 15%), suggesting high HP transfer within the studied communities. Significant network nestedness further suggests the existence of species that predominantly act as HP donors or recipients in the community. Species-level analyses showed that natives receive 80% more HP compared to alien species, and that alien plants donate 40% more HP than natives. HP receipt and donation were mediated by different floral traits and such effects were independent of plant origin (native or alien). The proportion of alien HP received significantly affected conspecific pollen tube success in natives, but not that of alien species. Synthesis. Our results suggest that HP transfer in invaded communities is widespread, and that native and alien species play different roles within HP transfer networks, which are mediated by a different suite of floral traits. Alien species, in particular, play a central role as HP donors and are more tolerant to HP receipt than natives—a finding that points to two overlooked mechanisms facilitating alien plant invasion and success within native co-flowering communities.

© 2019 The Authors. New Phytologist © 2019 New Phytologist Trust The role of pollination in the success of invasive plants needs to be understood because invasives have substantial effects on species interactions and ecosystem functions. Previous research has shown both that reproduction of invasive plants is often pollen limited and that invasive plants can have high seed production, motivating the questions: How do invasive populations maintain reproductive success in spite of pollen limitation? What species traits moderate pollen limitation for invaders? We conducted a phylogenetic meta-analysis with 68 invasive, 50 introduced noninvasive and 1931 native plant populations, across 1249 species. We found that invasive populations with generalist pollination or pollinator dependence were less pollen limited than natives, but invasives and introduced noninvasives did not differ. Invasive species produced 3× fewer ovules/flower and >250× more flowers per plant, compared with their native relatives. While these traits were negatively correlated, consistent with a tradeoff, this did not differ with invasion status. Invasive plants that produce many flowers and have floral generalisation are able to compensate for or avoid pollen limitation, potentially helping to explain the invaders’ reproductive successes.

Syftet med föreliggande uppsats är att bidra till en ökad förståelse för hur technostress yttrar sig hos projekt- och produktionsledare inom olika områden i mediebranschen. Detta genom att undersöka vilka technostress creators (techno-overload, techno-invasion, techno-complexity, techno-insecurity och techno-uncertainty) som påverkar denna yrkesgrupp, samt hur anställda hantera dessa. I genomförandet av studien har två kvalitativa- och en kvantitativ metod tillämpats. Den kvalitativa datainsamlingen utgjordes av en fokusgruppsdiskussion samt enskilda intervjuer med projekt- och produktionsledare verksamma i Malmö. Den kvantitativa undersökningen gjordes i form av en enkät som skickades både till projekt- ochproduktionsledare inom mediebranschen i Malmö, samt till Nätverket Pirayas medlemmar.Studien visar att projekt- och produktionsledare inom mediebranschen framförallt upplevertechno-overload samt techno-invasion. Insamlade data tyder också på att den medieteknik som främst ligger till grund för detta är e-post och mobiltelefoner. Tillsammans möjliggör de en hög arbetsbelastning som informanterna och respondenterna upplever som svår att hinna med under kontorstid. Därtill innebär medieteknikens mobilitet – och därmed arbetets tillgänglighet utanför kontoret – att informanterna och respondenterna tidvis har svårt att hålla isär arbetsliv och privatliv. Utlåtande från informanterna och respondenterna tyder emellertid på att förekomsten av techno-complexity, techno-insecurity och techno-uncertainty är låg hos projekt- och produktionsledare inom mediebranschen. / This study aims to examine whether project- and production managers within different areas of the media industry experience technostress due to any of the five technostress creators:techno-overload, techno-invasion, techno-complexity, techno-insecurity and techno-uncertainty. Furthermore, the study examines how employees handle the effects of these. In the study, both qualitative and quantitative methods have been applied. The qualitative data collection includes a focus group discussion as well as individual interviews with project- and production managers operating in Malmö. The quantitative data collection was conducted in the form of a survey sent to both project- and production managers in the media industry in Malmö and to Nätverket Piraya’s members. The results show that project- and production managers in the media industry mostly experience techno-overload and techno-invasion. The collected data indicate that information communication technologies (ICT) such as email and mobile phones are the main reason for this. Together, they enable a workload that is difficult for the respondents to keep up with and finish during office hours. The mobility of these ICT’s also allows the respondents to work outside the office, making it difficult for many to separate work and personal life. The study also shows that the presence of techno-complexity, techno-insecurity och techno-uncertainty is low among the respondents.

Lionfish (Pterois spp.), an invasive species native to the Indo-Pacific, have permanently established themselves throughout the greater Caribbean, Gulf of Mexico, and regions of the Western Atlantic ranging from as far north as North Carolina to central Brazil. As their fundamental range expands, lionfish threaten to migrate into estuarine environments as they have been found to tolerate low salinities and an eclectic range of temperatures. The physiological capacity of invasion was assessed by quantifying the visual ecology of lionfish utilizing corneal electroretinography (ERG) as well as their metabolic scope and hypoxia tolerances under various temperature-oxygen-regimes utilizing intermittent-flow respirometry. Seasonal changes in temperature-dissolved oxygen levels consistent with Atlantic/Gulf of Mexico inshore estuaries not only exceed the physiological tolerances of lionfish, but also constrain metabolic scope at sub-lethal levels by significantly limiting maximum metabolic rate across all temperatures. Median Scrit values were 33%, 39%, 46%, and 54% at 15, 20, 25, and 30℃ respectively. Luminous sensitivities, temporal resolutions (Flicker fusion frequency), and spectral sensitivities scaled similarly with other estuarine piscivores indicating lionfish possess a visual system that can function effectively within estuarine photic conditions. Overall, visual characteristics of estuaries will not pose as a significant barrier to lionfish, but minimum winter temperatures and hypoxia will pose controlling and limiting factors substantially preventing further inshore invasion. However, caution should still be advised as lionfish may capitalize on specific temporal and spatial scales that provide suitable habitat quality and abundance of prey items. Further insight is needed to forecast the effects of temperature-dissolved oxygen on lionfish metabolic-scope.

The spread of invasive species poses a major ecological and economical threat. Consequently there are ongoing efforts to develop a generalizable mechanism to predict establishment success of non-native species. One proposed mechanism to predict establishment success is propagule pressure, which is defined as the number of individuals introduced at a given time. Although some studies have demonstrated a positive correlation between propagule pressure and establishment success, others have not, and the effect of propagule pressure on establishment success remains unclear. To address this challenge, a strain of bacteria engineered with an Allee effect, a growth dynamic that is often associated with establishing species, was used. The timing between successive introduction events that resulted in establishment success was measured. It was observed that if the time between two introduction events was sufficiently long, growth did not occur. By manipulating the growth rate of the bacteria, it was shown that that the minimal time between the two introduction events that resulted in growth was constrained as growth rate decreased. Moreover, it was concluded that asymmetry in the density of bacteria introduced in the introduction events increased the maximum time between introduction events that resulted in growth. These results help to remedy conflicting data in the literature by identifying conditions where propagule pressure has, and does not have, a positive impact on establishment success. These findings can have major implications in understanding and predicting the unique population dynamics of invasive species.

No description available.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19529号 / 理博第4189号 / 新制||理||1601(附属図書館) / 32565 / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 大串 隆之, 教授 中野 伸一, 教授 曽田 貞滋 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第13029号 / 論医博第2111号 / 新制||医||1016(附属図書館) / 32987 / (主査)教授 大森 孝一, 教授 別所 和久, 教授 坂井 義治 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20230号 / 医博第4189号 / 新制||医||1019(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 野田 亮, 教授 武田 俊一, 教授 杉田 昌彦 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM