Partition Structure Research Articles

Important Practical Conditions for Getting the High-Quality Foam Concretes

Introduction. The most important reasons justifying the relevance of the research on the practical methods of reducing the consumption of materials in construction industry have been distinguished. The priorities of the Russian Federation referring to the foam concrete technology have been outlined. The level of reliability of the Internet resources describing properties of the dispersedly reinforced foam concretes has been briefly evaluated. The aim of the study is to establish the relationships between the individual properties of fiber, its quantity to the mass of cement ratio, and the most important operational properties of foam concrete manufactured using a single-stage technology.Materials and methods. The types and properties of raw materials used in the experimental research, the methods for controlling the properties of mixes and hardened foam concretes have been defined.Results. The relationship between the speed of phase transition of the viscoplastic properties of the foam concrete mixes into the elastic ones and the possibility of getting a high-quality structure of the hardened foam concrete have been briefly theoretically justified. The physical reasons influencing the direction and speed of forming the raw material dispersed particle clusters in the structure of the interpore partitions of foam concrete mixes have been revealed, which are the important factors to be considered in practice to get the high-strength foam concretes. Depending on the fiber concentration in the concrete mixture composition, the specifics of the fiber physical nature influence on the speed of phase transition from viscoplastic to elastic state have been established. It has been proved that the synergetic effect of dispersed reinforcement is achieved when fiber concentration is enough to provide the significant acceleration of the phase transition. New experimental data on the influence of the individual properties of fiber on the rheological and physico-mechanical properties of D500 foam concrete has been obtained.Discussion and Conclusion. The scientific explanation of the reasons for emergence of the electret effect on the surface of synthetic fiber has been given. It has been revealed that the discovered effect is induced by the specifics of the foam concrete mixture preparation using a single-stage technology. The most important practical conditions due to be met to get the high-strength foam concrete have been determined.

Fast CU decision method based on texture characteristics and decision tree for depth map intra-coding

As the demand for higher quality 3D videos continues to grow, the 3D extensions of the Efficient Video Coding (3D-HEVC) standard are gradually unable to meet the needs of users. Versatile Video Coding Standard (H. 266/VVC), as an advanced video coding standard, adopts the nested Multi-Type Tree quadtree (QTMT) partitioning structure that current fast depth map coding unit (CU) partitioning methods cannot apply. Therefore, we have designed a fast intra-frame CU partitioning algorithm for VVC 3D video depth maps. Our proposed algorithm in this article consists of two steps, including two sub-algorithms. First, by analyzing the relationship between image entropy and variance and depth map CU division, we establish a bi-criterion decision algorithm to determine whether the texture complexity of the current CU is low enough to terminate its partitioning process. Then, for CUs that have been determined by the first algorithm to need further partitioning, we use a decision tree model based on Light Gradient Boosting Machine (LGBM) to predict which direction of Rate-Distortion Optimization (RDO) calculation can be skipped, which can avoid some unnecessary RDO calculations in a certain direction. The final experiment demonstrated the effect of the proposed algorithm, which can reduce 47.65% complexity of VVC 3D video intra-coding with negligible 0.23% Bjøntegaard Delta Bitrate (BDBR) increase, superior to other advanced methods.

Оперативное диспетчерское управление водораспределением в оросительных системах по расчетному приращению объемов

Goal: to improve the methodological approach to developing an algorithm for operational dis-patch control of water distribution based on the calculated increment of water volumes in irri-gation canals. Materials and methods: the dispatch control methodology is described, which is based on the typification of flow conditions between two partitioning structures in technical and functional directions, as well as on the development of systems for unifying channels and their modes using similarity theory methods, which are widely used in hydromechanics and hydraulics. The basis for the implementation of the similarity theory is the principle of using similarity numbers, that is, combinations of dimensionless parameters that determine the char-acteristics of the unsteady motion of a heavy, incompressible, viscous fluid in channels. Re-sults: the general tasks of the dispatcher were determined to re-regulate the hydraulic regime of sections of the irrigation system, without tying them to specific types of hydraulic struc-tures. The main provisions of the method of dispatch control of water distribution based on the calculated increment of volumes, determination of the time of re-regulation between the main and compensating processes of re-regulation are substantiated. Four types of situations are identified when solving dispatch problems of water distribution, which are determined by comparing the volumes and flow rates installed on the site, for each of which the inherent re-regulation order is determined. Conclusion: the article outlines a new methodological ap-proach that ensures the joint use of the method of similarity theory and a simulation experi-ment with the Saint-Venant equations for steady and unsteady water flow in the canals of ir-rigation systems, to solve problems of operational dispatch control of water distribution ac-cording to the calculated increment of volumes.

Combinatory effect of ALA-PDT and itraconazole in the treatment of cutaneous protothecosis

BackgroundAs a rare subcutaneous infection, protothecosis is easily misdiagnosed. Similar to other subcutaneous infection, there is no unified standard for treatment, for cases not suitable for surgery, clinicians often use antifungal drugs based on their experience, and the course of treatment varies from several months to several years. Based on the fact that there are few relevant materials and researches on photodynamic therapy (PDT), we conducted a study based on a clinical case that used oral itraconazole combined with 5-aminolevylinic acid photodynamic therapy (ALA-PDT) to treat a patient with cutaneous protothecosis caused by Prototheca wicherhamii. MethodsDifferent concentrations of ALA and different light doses were used to investigate the effects of ALA-PDT on the growth inhibition of P. wickerhamii in vitro with Colony-counting Methods. And we used transmission electron microscopy (TEM) to visualize the structural changes and the effects of ALA-PDT treating on cellular structures of the P. wickerhamii. Futher, we performed the susceptibility test of P. wickerhamii to itraconazole before and after ALA-PDT in vitro. ResultsWe have successfully treated a patient with cutaneous protothecosis caused by P. wickerhamii by using combination therapy in a total of 9-week course of treatment. In vitro, ALA-PDT can inhibit the growth of P. wickerhamii when the ALA concentration was 5 mg/mL (P < 0.01), and this effect became stronger as the concentration of ALA or light dose is increased. Using TEM, we confirmed that ALA-PDT can disrupt the cell wall structure and partition structure of P. wickerhamii, which may contribute to its inhibitory effect. Further studies showed that the MIC of itraconazole for P. wickerhamii was decreased after ALA-PDT. ConclusionsALA-PDT combined with oral itraconazole can be used to treat cutaneous protothecosis. Accordingly, ALA-PDT can destroy the cell wall and partition structure of P. wickerhamii leading to an inhibitory effect on it in vitro, and the effect is enhanced with the increase of ALA concentration and light dose. Also, the sensitivity of P. wickerhamii to itraconazole is observed increased after ALA-PDT. So our study provides a theoretical basis for the promising treatment against cutaneus protothecosis.

Stable partitions for proportional generalized claims problems

We consider a set of agents who have claims on an endowment that is not large enough to cover all claims. Agents can form coalitions but a minimal coalition size θ is required to have positive coalitional funding that is proportional to the sum of the claims of its members. We analyze the structure of stable partitions when coalition members use well-behaved rules to allocate coalitional endowments, e.g., the well-known constrained equal awards rule (CEA) or the constrained equal losses rule (CEL). For continuous, (strictly) resource monotonic, and consistent rules, stable partitions with (mostly) θ-size coalitions emerge. For CEA and CEL we provide algorithms to construct such a stable partition formed by (mostly) θ-size coalitions.

Dual-aeolotropic electrically conductive flexible composite membrane with enhanced red fluorescence

New-typed dual-aeolotropic conductive flexible composite membrane (DCFCM), was devised and fabricated by parallel electrospinning. DCFCM consists of two layers that are strongly coupled to form a top-to-bottom structure. Janus nanoribbon (JN), possessing two distinct sides (respectively conducting and insulating-fluorescent side), is highly oriented in each layer of DCFCM. The top-to-bottom structure of DCFCM effectuates the macro-level zoning, and the JN as a conductive and constitutive function in DCFCM realizes the micro-level zoning, which achieves the combination of microstructure and macroscopic structure in DCFCM. Thus, DCFCM simultaneously performs dual-aeolotropic electrical conduction and enhanced red luminescence due to the partitioning structures which aid in minimizing adverse interactions between the conductive and luminescent materials. The conducting anisotropy of each layer in the DCFCM can be adjusted by varying the PANI content. The conductance ratio can reach 108 when the PANI content is 60–70 %. Additionally, DCFCM exhibits strong red emission, originating from the allowed 5D0→7F2 (593 nm), 5D0→7F2 (616 nm) energy levels transitions of Eu3+ ions. This work provides a simple and effective method to fabricate aeolotropic conductive membranes with novel multifunctional properties.

Research on day-ahead and intraday scheduling strategy of distribution network based on dynamic partitioning

With the massive participation of new energy in the operation of distribution network (DN), the uncertainties arising from both load and renewable generation have brought challenges to its secure and reliable operation. In this paper, a model of day-ahead and intraday optimal scheduling based on dynamic partitioning (DP) of DN is constructed to realize the refinement of operation in both temporal and spatial dimensions, as well as to improve the reliability of system operation. For the strong fluctuation characteristics of the source-load in DN, the DP is achieved under the premise that the partition structure in each period is tight and the internal power supply has the ability to balance the power fluctuations. In order to improve the regional autonomy of DN, a day-ahead multi-objective optimal scheduling model is constructed based on the DP with the optimization objectives of weak inter-partition power coupling, lowest deficiency rate of flexibility, and lowest operating cost. And a scheme for articulation is proposed to ensure the effective guidance of day-ahead for intraday. Then the intraday dispatch model is constructed by shifting the focus to the incorporate characteristics of DP and quickly smooth the net load fluctuations. Finally, the performance and reliability of the proposed models are verified via case studies.

An SEIHR model with age group and social contact for analysis of Fuzhou COVID-19 large wave

BackgroundThe structure of age groups and social contacts of the total population influenced infection scales and hospital-bed requirements, especially influenced severe infections and deaths during the global prevalence of COVID-19. Before the end of the year 2022, Chinese government implemented the national vaccination and had built the herd immunity cross the country, and announced Twenty Measures (November 11) and Ten New Measures (December 7) for further modifications of dynamic zero-COVID polity on the Chinese mainland. With the nation-wide vaccination and modified measures background, Fuzhou COVID-19 large wave (November 19, 2022–February 9, 2023) led by Omicron BA.5.2 variant was recorded and prevailed for three months in Fujian Province. MethodsA multi-age groups susceptible-exposed-infected-hospitalized-recovered (SEIHR) COVID-19 model with social contacts was proposed in this study. The main object was to evaluate the impacts of age groups and social contacts of the total population. The idea of Least Squares method was governed to perform the data fittings of four age groups against the surveillance data from Fujian Provincial Center for Disease Control and Prevention (Fujian CDC). The next generation matrix method was used to compute basic reproduction number for the total population and for the specific age group. The tendencies of effective reproduction number of four age groups were plotted by using the Epiestim R package and the SEIHR model for in-depth discussions. The sensitivity analysis by using sensitivity index and partial rank correlation coefficients values (PRCC values) were operated to reveal the differences of age groups against the main parameters. ResultsThe main epidemiological features such as basic reproduction number, effective reproduction number and sensitivity analysis were extensively discussed for multi-age groups SEIHR model in this study. Firstly, by using of the next generation matrix method, basic reproduction number R0 of the total population was estimated as 1.57 using parameter values of four age groups of Fuzhou COVID-19 large wave. Given age group k, the values of R0k (age group k to age group k), the values of R0k (an infected of age group k to the total population) and the values of R^0k (an infected of the total population to age group k) were also estimated, in which the explorations of the impacts of age groups revealed that the relationship R0k>R0k>R^0k was valid. Then, the fluctuating tendencies of effective reproduction number Rt were demonstrated by using two approaches (the surveillance data and the SEIHR model) for Fuzhou COVID-19 large wave, during which high-risk group (G4 group) mainly contributed the infection scale due to high susceptibility to infection and high risks to basic diseases. Further, the sensitivity analysis using two approaches (the sensitivity index and the PRCC values) revealed that susceptibility to infection of age groups played the vital roles, while the numerical simulation showed that infection scale varied with the changes of social contacts of age groups. The results of this study claimed that the high-risk group out of the total population was concerned by the local government with the highest susceptibility to infection against COVID-19. ConclusionsThis study verified that the partition structure of age groups of the total population, the susceptibility to infection of age groups, the social contacts among age groups were the important contributors of infection scale. The less social contacts and adequate hospital beds for high-risk group were profitable to control the spread of COVID-19. To avoid the emergence of medical runs against new variant in the future, the policymakers from local government were suggested to decline social contacts when hospital beds were limited.

Fast Decision-Tree-Based Series Partitioning and Mode Prediction Termination Algorithm for H.266/VVC

With the advancement of network technology, multimedia videos have emerged as a crucial channel for individuals to access external information, owing to their realistic and intuitive effects. In the presence of high frame rate and high dynamic range videos, the coding efficiency of high-efficiency video coding (HEVC) falls short of meeting the storage and transmission demands of the video content. Therefore, versatile video coding (VVC) introduces a nested quadtree plus multi-type tree (QTMT) segmentation structure based on the HEVC standard, while also expanding the intra-prediction modes from 35 to 67. While the new technology introduced by VVC has enhanced compression performance, it concurrently introduces a higher level of computational complexity. To enhance coding efficiency and diminish computational complexity, this paper explores two key aspects: coding unit (CU) partition decision-making and intra-frame mode selection. Firstly, to address the flexible partitioning structure of QTMT, we propose a decision-tree-based series partitioning decision algorithm for partitioning decisions. Through concatenating the quadtree (QT) partition division decision with the multi-type tree (MT) division decision, a strategy is implemented to determine whether to skip the MT division decision based on texture characteristics. If the MT partition decision is used, four decision tree classifiers are used to judge different partition types. Secondly, for intra-frame mode selection, this paper proposes an ensemble-learning-based algorithm for mode prediction termination. Through the reordering of complete candidate modes and the assessment of prediction accuracy, the termination of redundant candidate modes is accomplished. Experimental results show that compared with the VVC test model (VTM), the algorithm proposed in this paper achieves an average time saving of 54.74%, while the BDBR only increases by 1.61%.

Divide and conquer: Spatial and temporal resource partitioning structures benthic cyanobacterial mats.

Benthic cyanobacterial mats are increasing in abundance worldwide with the potential to degrade ecosystem structure and function. Understanding mat community dynamics is thus critical for predicting mat growth and proliferation and for mitigating any associated negative effects. Carbon, nitrogen, and sulfur cycling are the predominant forms of nutrient cycling discussed within the literature, while metabolic cooperation and viral interactions are understudied. Although many forms of nutrient cycling in mats have been assessed, the links between niche dynamics, microbial interactions, and nutrient cycling are not well described. Here, we present an updated review on how nutrient cycling and microbial community interactions in mats are structured by resource partitioning via spatial and temporal heterogeneity and succession. We assess community interactions and nutrient cycling at both intramat and metacommunity scales. Additionally, we present ideas and recommendations for research in this area, highlighting top-down control, boundary layers, and metabolic cooperation as important future directions.

Structured invariant subspace and decomposition of systems with time delays and uncertainties

AbstractThis article discusses invariant subspaces of a matrix with a given partition structure. The existence of a nontrivial structured invariant subspace is equivalent to the possibility of decomposing the associated system with multiple feedback blocks such that the feedback operators are subject to a given constraint. The formulation is especially useful in the stability analysis of time‐delay systems using the Lyapunov–Krasovskii functional approach where computational efficiency is essential in order to achieve accuracy for large scale systems. The set of all structured invariant subspaces are obtained (thus all possible decompositions are obtained as a result) for the coupled differential‐difference equations (DDE) associated with the DDE of retarded and neutral types, as well as systems with a time‐varying delay. It was shown that the known ad hoc methods of reducing the dimensions of delay channels can be considered as special cases of decomposition where one subsystem has trivial dynamics. The reduction of computational cost is demonstrated by a numerical example. For the general case, a recursive procedure is developed to obtain the set of all structured invariant subspaces. Based on this procedure, a method is presented to obtain a nontrivial structured invariant subspace that considers computational efficiency and increased possibility of terminating in a finite number of steps.

Fast HEVC inter-frame coding based on LSTM neural network technology

High Efficiency Video Coding (HEVC) is the most commonly used video coding standard. However, its high coding complexity is a heavy burden for real-time video applications. But, coding tools designed based on traditional coding frameworks have reached limits. Furthermore, existing low-complexity video coding methods have not thoroughly analyzed the characteristics of compressed video, making it impossible to develop targeted models to reduce coding complexity. Therefore, in this research, a fast HEVC inter-frame coding technique is proposed. Firstly, we perform a characteristics analysis of HEVC inter-frame coding to explore the correlation between video frames. Secondly, we develop an Inter-Frame Feature Transfer-Long Short-Term Memory (IFFT-LSTM) model to obtain the optimal coding tree unit (CTU) partition structure. Thirdly, we embed the IFFT-LSTM model into the HEVC test platform. The experimental results show that suggested method can effectively reduce the HEVC inter-frame coding complexity with a small amount of rate-distortion (RD) performance loss while maintaining acceptable subjective video quality.

New Evolutionary Algorithms for Determining Consensus of Ordered Partition Collectives

The ordered partition structure is helpful when an expert has to classify elements of a set into given classes. Finding consensus for an ordered partition collective is very important in making decisions. A 2-Optimality (O2) consensus best represents a collective, and distances between it and collective elements are uniform. However, finding such consensus has yet to be widely examined for ordered partition collectives. The best algorithm for this task in the literature is the HG3 algorithm. This study proposed three evolutionary algorithms to solve this problem. The algorithm (μ, λ)-IES is developed based on (μ, λ)-ES. The IHG2 algorithm is developed by fuzing the local search, elitism strategy, duplicate elimination, dynamic crossover rate, and dynamic mutation rate. The IHG3 algorithm is increasing the balance of exploration and exploitation. This algorithm is developed by fuzing the longest-distance strategy (KLD), elitism strategy (IEBL), local search, duplicate elimination, dynamic crossover rate, and dynamic mutation rate. The simulation results show that these algorithms generate high consensus quality. The IHG3 algorithm provides consensus with the best quality in an acceptable running time.

Fast intra coding in AVS3 based on direct non-first pre-coding skip

The third generation of Audio Video Coding Standard (AVS3) adopts sophisticated block partitioning structure with a multi-type tree, which includes Quad-Tree (QT), Binary-Tree (BT), and Extend Quad-Tree (EQT). During multi-type tree recursive block partitioning and pre-coding process of encoding, each Coding Unit (CU) of each Size at each Location (CUeSeL) of the picture is repeatedly pre-coded many times when visiting each branch of each tree. Although there are early termination mechanism, the number of visits for each CUeSeL is still very high and up to more than fifty. This process brings very high coding complexity. In order to reduce the coding complexity of AVS3, this paper proposes a method named Direct Non-First Pre-coding Skip (DNFPS) for a CUeSeL to directly and completely skip all non-first pre-coding under specific conditions. The conditions include, but are not limited to, those related to the first pre-coding. The contributions of the paper are as follows. In I pictures, for a CUeSeL with top-left location (x, y), if both x and y are multiples of 64 or if a set of conditions related to first pre-coding is satisfied, then each non-first pre-coding is skipped, and the coding result of the first pre-coding is reused for each non-first pre-coding skipped. In non-I pictures, each non-first pre-coding is skipped, and the coding result of the first pre-coding is reused for each non-first pre-coding skipped, provided a set of conditions related to first pre-coding is satisfied. The experimental results demonstrate that DNFPS has a negligible impact on coding efficiency under All Intra (AI) configurations, and coding runtime is reduced by 16 %.

Synergy of Stag2-Cohesin Loss Results in Expansion of Npm1c-Mutant Hematopoietic Stem and Progenitor Cells

STAG2 is a member of cohesin complex that is recurrently mutated in &amp;gt;10 cancers and is essential in maintaining the integrity of the 3D genome partitioning structure known as topologically structural domains (TADs). Our previous work has demonstrated that depletion of various cohesin factors, including Stag2, leads to increased hematopoietic stem and progenitor population (HSPC) self-renewal and myeloid-biased differentiation. Loss of Stag2 leads to impaired sub-TADs and affects key hematopoietic transcription factors, such as PU.1, to access and engage their target genes. Yet, the extent and cooperative transformational role of Stag2-cohesin with leukemia driver mutations, such as Npm1c, remains unexplored. To determine whether Stag2-cohesin regulates leukemic 3D chromatin organization, we generated dual Stag2 Δ Npm1 c/+ murine models with tamoxifen inducible UbcCreER T2. After 4 weeks, HSPCs (LSK cells; Lin-Sca1+Kit+) are increased in Stag2 Δ Npm1 c/+ double mutant mice ( Figure 1A). Within LSK, Stag2 Δ Npm1 c/+ but not Npm1 c/+ has marked expansion of the myeloid bias MPP2 (LSK+Flk2-Cd150+Cd48+) and MPP3 (LSK+Flk2-Cd150-Cd48+) compartment. Interestingly, Stag2 Δ single mutant exhibit LSK and MPP3 expansion at 16 weeks, suggesting the early expansion of HSPC compartment is the result of Stag2 ΔNpm1 c/+ synergistic acceleration. No difference in serial replating of LSK and GMP (LSK-Cd34+FcyRII+) cells were observed between Npm1 c/+ and Stag2 Δ Npm1 c/+. However, Stag2 Δ Npm1 c/+ LSK cells had impaired reconstitution capacity and myeloid biased output in primary and secondary transplantation. To determine if the blockage is specific to Stag2-cohesin loss, we generated the Smc3/Npm1c double mutant mice, where both Stag1-cohesin and Stag2-cohesin complexes were partially depleted upon heterozygous deletion of Smc3. Interestingly, there were no changes in LSK or MPP3 population in Smc3 +/- Npm1 c/+ mice, suggesting it is specific to Stag2-cohesin loss which obstructs differentiation in Npm1 c/+ HSPC. Mechanistically, we performed bulk ATAC-seq on sorted HSC LT (LSK+Flk2-Cd150+Cd48-) and MPP3 population, as poor long-term reconstitution suggests functional alteration in HSC LT. Comparing to WT, both Stag2 Δ and Stag2 Δ Npm1 c/+ HSC LT have increased chromatin accessibility, while only Stag2 Δ Npm1 c/+ MPP3 have persistent opening of chromatin. Motif analysis of increased accessible peaks identified RUNX2, GATA3 and MEIS1 are among the increased accessible region in Stag2 Δ Npm1 c/+ MPP3, which reflects the increased myeloid output in the transplantation. Recently, various group have suggested that Npm1c directly binds to chromatin and drives the overexpression of genes, especially at HOX clusters and MEIS1. This suggests a possible synergistic mechanism which Stag2-cohesin regulates chromatin accessibility of key TF loci, which influences normal and leukemic stem and progenitor differentiation. To comprehensively profile the LSK population, we performed scRNAseq at 4 weeks post mutation activation, results showed a marked immune pathway activation in Stag2 Δ Npm1 c/+ LSK cells. To inter cell fate transition, we employed CellDancer, an RNA velocity based algorithm and found that Stag2 Δ Npm1 c/+ MPP cells have altered differentiation trajectory and delayed kinetics at MPP3 stages, suggesting a differentiation block ( Figure 1B). In conjunction with our results, we postulate that Stag2-cohesin regulates TF interactions with regulatory elements during cell fate transitions. We are currently investigating the direct interaction of Stag2-cohesin with regulatory elements in Npm1 c/+ cells and compare to WT and Stag2 Δ Npm1 c/+ cells. We will investigate the 3D genome organization of Npm1 c/+ and Stag2 Δ Npm1 c/+ cells to determine whether Stag2 loss induces the phenotypic changes via Ctcf-dependent or independent manner.

Stag2-Cohesin Loss Attenuates Flt3 ITD Myeloid Blast Expansion Yet Preserves Mutant HSC

FLT3 is mutated through an internal tandem duplication (ITD) in 20-25% of acute myeloid leukemia (AML), driving aberrant STAT5/AKT signaling and leukemogenesis. Murine modelling of ITD showed marked myeloid progenitor expansion and hematopoietic stem cell (HSC) exhaustion in various co-mutant settings. Here we present a Stag2 Δ Flt3 ITD model with stark reversal of these two aforementioned features. STAG2, a cohesin complex member, maintains the integrity of the 3D genome partitioning structure known as topologically structural domains. Loss of Stag2 impairs the access and engagement of key hematopoietic transcription factors such as PU.1 to their target genes. sAML is diagnosed when patients present leukemia with known history of hematological malignancies or chemotherapy/radiotherapy treatment. Comparing to de novo AML, sAML often arises in older patients and harbors a poor prognosis with a 5-year overall survival rate of &amp;lt;30%. Advances in genomic studies found various epigenetic mutations, such as STAG2, are often associated with sAML and AML-myelodysplastic related changes (MRC) subtype. STAG2 mutations are found in 14-20% of sAML cases and is suggested to reside within a dominant clone during the pre-leukemia phase, MDS to sAML transformation, such as with FLT3 ITD acquisition and persists during remission. To understand the mechanistic contribution of STAG2-cohesin loss with FLT3 ITD, we generated sequential mutagenesis murine models where the order of Stag2 and Flt3 ITD mutation is set as either ITD 1st Stag2 2nd ( de novo like) or Stag2 1stITD 2nd (sAML like) using tamoxifen-inducible Cre/Flpo recombinase or pIpC-inducible Mx1Cre. In the de novo like model, ITD is constitutively active then Stag2 is deleted when mice reach 6-8 weeks of age. Surprisingly, loss of Stag2 attenuates LSK to MP transition at 4 weeks post deletion, while MPP3 remains elevated, suggesting aberrant remodeling of myeloid differentiation. In the sAML like model, Stag2 is deleted via Mx1Cre and waited for 4 months to mimic the MDS phase, which is then followed by activation of ITD mutation via Flpo, which represents the MDS to sAML transformation. After activating both mutations, mice were followed for another 4 months before analyzing the hematopoietic stem and progenitor compartment. In contrast to the de novo like model, sequential Stag2 1stITD 2nd preserves the HSC population defined by either immunophenotyping or transcriptome via scRNAseq ( Figure 1). The mutant HSC is more quiescent but retains the capacity to reconstitute lethally irradiated recipients in the short term. Similar to the de novo like model, sequential Stag2 1stITD 2nd mice also exhibits a blocked myeloid differentiation. Comparing to ITD mutant, Stag2 1stITD 2nd LSK cells have decreased expression of Socs2 and Cish. While functionally determining the role of mutant HSC, we are performing RNA-seq during at early timepoints post ITD activation to determine how preceding Stag2 mutation could have altered the stem cell fate decision. Targeted therapy with inhibitors of FLT3 have had an overall survival benefit in FLT3-mutant AML, though the magnitude of effect has been modest. STAG2 mutations are more likely to be identified in poor responders to FLT3 inhibition as both reported by us with Pexidartinib treatment, as well as in the setting of Crenolanib treatment where expansion of the STAG2-mutant clone was observed during treatment. Thus, remodeling of the chromatin landscape though altered CTCF binding or cohesin function might impact leukemia identity in FLT3-mutant AML. Our data highlights an important regulatory role of Stag2-cohesin in Flt3 ITD mediated leukemogenesis, while generating a model that mimics the genetic evolution of sAML. This model will not only shed light on the sAML pathogenesis but also with creates a pre-clinical testing platform with potential therapeutic relevance.

Behavioral dominance interactions between two species of burying beetles (Nicrophorus orbicollis and Nicrophorus pustulatus).

Closely related species with ecological similarity often aggressively compete for a common, limited resource. This competition is usually asymmetric and results in one species being behaviorally dominant over the other. Trade-offs between traits for behavioral dominance and alternative strategies can result in different methods of resource acquisition between the dominant and subordinate species, with important consequences for resource partitioning and community structure. Body size is a key trait thought to commonly determine behavioral dominance. Priority effects (i.e., which species arrives at the resource first), however, can also determine the outcome of interactions, as can species-specific traits besides size that give an advantage in aggressive contests (e.g., weapons). Here, we test among these three alternative hypotheses of body size, priority effects, and species identity for what determines the outcome of competitive interactions among two species of burying beetles, Nicrophorus orbicollis and N. pustulatus. Both overlap in habitat and seasonality and exhibit aggressive competition over a shared breeding resource of small vertebrate carrion. In trials, we simulated what would happen upon the beetles' discovery of a carcass in nature by placing a carcass and one beetle of each species in a container and observing interactions over 13 h trials (n = 17 trials). We recorded and categorized interactions between beetles and the duration each individual spent in contact with the carcass (the key resource) to determine which hypothesis predicted trial outcomes. Body size was our only significant predictor; the largest species won most aggressive interactions and spent more time in contact with the carcass. Our results offer insight into the ecology and patterns of resource partitioning of N. orbicollis and N. pustulatus, the latter of which is unique among local Nicrophorus for being a canopy specialist. N. pustulatus is also unique among all Nicrophorus in using snake eggs, in addition to other carrion, as a breeding resource. Our results highlight the importance of body size and related trade-offs in ecology and suggest parallels with other coexisting species and communities.

HTF: Homogeneous Tree Framework for Differentially-Private Release of Large Geospatial Datasets with Self-Tuning Structure Height.

Mobile apps that use location data are pervasive, spanning domains such as transportation, urban planning and healthcare. Important use cases for location data rely on statistical queries, e.g., identifying hotspots where users work and travel. Such queries can be answered efficiently by building histograms. However, precise histograms can expose sensitive details about individual users. Differential privacy (DP) is a mature and widely-adopted protection model, but most approaches for DP-compliant histograms work in a data-independent fashion, leading to poor accuracy. The few proposed data-dependent techniques attempt to adjust histogram partitions based on dataset characteristics, but they do not perform well due to the addition of noise required to achieve DP. In addition, they use ad-hoc criteria to decide the depth of the partitioning. We identify density homogeneity as a main factor driving the accuracy of DP-compliant histograms, and we build a data structure that splits the space such that data density is homogeneous within each resulting partition. We propose a self-tuning approach to decide the depth of the partitioning structure that optimizes the use of privacy budget. Furthermore, we provide an optimization that scales the proposed split approach to large datasets while maintaining accuracy. We show through extensive experiments on large-scale real-world data that the proposed approach achieves superior accuracy compared to existing approaches.

On the number of regions of piecewise linear neural networks

Many feedforward neural networks (NNs) generate continuous and piecewise-linear (CPWL) mappings. Specifically, they partition the input domain into regions on which the mapping is affine. The number of these so-called linear regions offers a natural metric to characterize the expressiveness of CPWL NNs. The precise determination of this quantity is often out of reach in practice, and bounds have been proposed for specific architectures, including for ReLU and Maxout NNs. In this work, we generalize these bounds to NNs with arbitrary and possibly multivariate CPWL activation functions. We first provide upper and lower bounds on the maximal number of linear regions of a CPWL NN given its depth, width, and the number of linear regions of its activation functions. Our results rely on the combinatorial structure of convex partitions and confirm the distinctive role of depth which, on its own, is able to exponentially increase the number of regions. We then introduce a complementary stochastic framework to estimate the average number of linear regions produced by a CPWL NN. Under reasonable assumptions, the expected density of linear regions along any 1D path is bounded by the product of depth, width, and a measure of activation complexity (up to a scaling factor). This yields an identical role to the three sources of expressiveness: no exponential growth with depth is observed anymore.

Multi-area state estimation for active distribution networks under multiple uncertainties: An affine approach

An enormous challenge for the state estimation (SE) process in large-scale distribution networks lies in how to deal with multiple uncertainties and the increasing computational tasks simultaneously. This paper aims to address the issue and propose a multi-area architecture for perceiving system status with uncertain inputs. The first step involves the introduction of a novel Louvain-flow-based partition structure, which effectively divides large-scale unbalanced distribution networks into several sub-areas. Subsequently, an affine state estimation (ASE) model, employing the Neumann series method, is formulated for each sub-area, taking into account uncertainties in system measurements and line parameters. Finally, the interior-point filter line-search algorithm combined with consensus theory is utilized to solve all local ASE models, and the interaction of boundary state between adjacent sub-areas is focused and completed, to output the global state results of the distribution network precisely. Case studies are presented to verify that the proposed distributed ASE model yields obvious advantages in tracking system uncertainties by contrast with the existing SE model.