Physiological and molecular responses of invasive cyanobacterium Raphidiopsis raciborskii to ambient phosphorus deficiency

Raphidiopsis raciborskii can cause harmful cyanobacterial blooms when concentrations of environme ntal pho sphorus(P)are very low,thus the physiological and molecular mechanisms involved in the acclimation to P need to be characterized better.The growth,chlorophyll fluorescence,alkaline phosphatase,and expression of genes directly involved in P assimilation were compared in the R.raciborskii FACHB1496 strain grown with and without inorganic P.The specific growth rate(μ),Chl a,and six fluorescence parameters(minimal fluorescence(F),maximal fluorescence(F),maximal variable fluorescence(F),electron transport flux(further than QA)per RC(ET/RC),quantum yield of the electron transport in PSⅡ(?),and the probability that an electron from a trapped exciton is moved into the electron transport chain beyond Q~-(Ψ))markedly decreased in R.raciborskii in response to experimental P-deficiency.In contrast,the relative variable fluorescence at the J-step(V),trapped energy flux(leading to QA reduction)per RC(TR/RC),and alkaline phosphatase activity significantly increased.In addition,gene expressions involved in the alkaline phosphatase(phoAl and phoA2),high-affinity inorganic P transporter(pstSl),phosphonate transporter and metabolism(phnD and phnM),and nucleotidase(nucH)were significantly upregulated under P deficiency.However,physiological and molecular responses were resumed rapidly after P re-supplementation following P-deficient conditions.Our results highlight that R.raciborskii can perform coordinated and complex cellular and physiological responses to cope with P deficiency,reflecting R.raciborskii’s multi-faceted machinery to respond to environmental P fluctuations.

Fuzzy-based indoor scene modeling with differentiated examples

Well-designed indoor scenes incorporate interior design knowledge,which has been an essential prior for most indoor scene modeling methods.However,the layout qualities of indoor scene datasets are often uneven,and most existing data-driven methods do not differentiate indoor scene examples in terms of quality.In this work,we aim to explore an approach that leverages datasets with differentiated indoor scene examples for indoor scene modeling.Our solution conducts subjective evaluations on lightweight datasets having various room configurations and furniture layouts,via pairwise comparisons based on fuzzy set theory.We also develop a system to use such examples to guide indoor scene modeling using user-specified objects.Specifically,we focus on object groups associated with certain human activities,and define room features to encode the relations between the position and direction of an object group and the room configuration.To perform indoor scene modeling,given an empty room,our system first assesses it in terms of the user-specified object groups,and then places associated objects in the room guided by the assessment results.A series of experimental results and comparisons to state-of-the-art indoor scene synthesis methods are presented to validate the usefulness and effectiveness of our approach.

A Differential Privacy Budget Allocation Method Combining Privacy Security Level

Trajectory privacy protection schemes based on suppression strategies rarely take geospatial constraints into account,which is made more likely for an attacker to determine the user’s true sensitive location and trajectory.To solve this problem,this paper presents a privacy budget allocation method based on privacy security level(PSL).Firstly,in a custom map,the idea of P-series is contributed to allocate a given total privacy budget reasonably to the initially sensitive locations.Then,the size of privacy security level for sensitive locations is dynamically adjusted by comparing it with the customized initial level threshold parameterµ.Finally,the privacy budget of the initial sensitive location is allocated to its neighbors based on the relationship between distance and degree between nodes.By comparing the PSL algorithm with the traditional allocation methods,the results show that it is more flexible to allocate a privacy budget without compromising location privacy under the same preset conditions.