Division Block Research Articles

CADC-FPRLE: Content-aware deduplication clustering analysis using file partitioning and a running length encoder for cloud storage optimization

To address this storage issue, we propose a Content-Aware Deduplication Clustering Analysis for Cloud Storage Optimization (CADC-FPRLE) based on a file partitioning running length encoder. At first, preprocessing was done by indexing, counting terms, cleansing, and tokenizing. Further multi-objective clustering points are analysed based on the bisecting divisible partition block, which divides a set of documents. The count terms are filtered from the divisible blocks and make up the count terms content block. Using Content-Aware Multi-Hash Ensemble Clustering (CAMH-EC) to group the similar blocks into clusters. This creates a high-dimensional Euclidean interval to create the number of clusters, and points are performed randomly to set the initial collection. Then, the Magnitude Vector Space Rate (MVSR) estimates the similarity distance between the groups to select the highest scatter value content for indexing. Finally, the Running Block Parity Encoder (RBPE) generates similarity parity in order to reduce the content to a redundant, singularized file in order to optimise storage. This implementation proves a higher level of storage optimization compared to the previous system than other methods.

JCAD deficiency delayed liver regenerative repair through the Hippo-YAP signalling pathway.

Liver regeneration retardation post partial hepatectomy (PH) is a common clinical problem after liver transplantation. Identification of key regulators in liver regeneration post PH may be beneficial for clinically improving the prognosis of patients after liver transplantation. This study aimed to clarify the function of junctional protein-associated with coronary artery disease (JCAD) in liver regeneration post PH and to reveal the underlying mechanisms. JCAD knockout (JCAD-KO), liver-specific JCAD-KO (Jcad△Hep) mice and their control group were subjected to 70% PH. RNA sequencing was conducted to unravel the related signalling pathways. Primary hepatocytes from KO mice were treated with epidermal growth factor (EGF) to evaluate DNA replication. Fluorescent ubiquitination-based cell cycle indicator (FUCCI) live-imaging system was used to visualise the phases of cell cycle. Both global and liver-specific JCAD deficiency postponed liver regeneration after PH as indicated by reduced gene expression of cell cycle transition and DNA replication. Prolonged retention in G1 phase and failure to transition over the cell cycle checkpoint in JCAD-KO cell line was indicated by a FUCCI live-imaging system as well as pharmacologic blockage. JCAD replenishment by adenovirus reversed the impaired DNA synthesis in JCAD-KO primary hepatocyte in exposure to EGF, which was abrogated by a Yes-associated protein (YAP) inhibitor, verteporfin. Mechanistically, JCAD competed with large tumour suppressor 2 (LATS2) for WWC1 interaction, leading to LATS2 inhibition and thereafter YAP activation, and enhanced expression of cell cycle-associated genes. JCAD deficiency led to delayed regeneration after PH as a result of blockage in cell cycle progression through the Hippo-YAP signalling pathway. These findings uncovered novel functions of JCAD and suggested a potential strategy for improving graft growth and function post liver transplantation. JCAD deficiency leads to an impaired liver growth after PH due to cell division blockage. JCAD competes with LATS2 for WWC1 interaction, resulting in LATS2 inhibition, YAP activation and enhanced expression of cell cycle-associated genes. Delineation of JCADHippoYAP signalling pathway would facilitate to improve prognosis of acute liver failure and graft growth in living-donor liver transplantation.

During heat stress in Myxococcus xanthus, the CdbS PilZ domain protein, in concert with two PilZ-DnaK chaperones, perturbs chromosome organization and accelerates cell death.

C-di-GMP is a bacterial second messenger that regulates diverse processes in response to environmental or cellular cues. The nucleoid-associated protein (NAP) CdbA in Myxococcus xanthus binds c-di-GMP and DNA in a mutually exclusive manner in vitro. CdbA is essential for viability, and CdbA depletion causes defects in chromosome organization, leading to a block in cell division and, ultimately, cell death. Most NAPs are not essential; therefore, to explore the paradoxical cdbA essentiality, we isolated suppressor mutations that restored cell viability without CdbA. Most mutations mapped to cdbS, which encodes a stand-alone c-di-GMP binding PilZ domain protein, and caused loss-of-function of cdbS. Cells lacking CdbA and CdbS or only CdbS were fully viable and had no defects in chromosome organization. CdbA depletion caused post-transcriptional upregulation of CdbS accumulation, and this CdbS over-accumulation was sufficient to disrupt chromosome organization and cause cell death. CdbA depletion also caused increased accumulation of CsdK1 and CsdK2, two unusual PilZ-DnaK chaperones. During CdbA depletion, CsdK1 and CsdK2, in turn, enabled the increased accumulation and toxicity of CdbS, likely by stabilizing CdbS. Moreover, we demonstrate that heat stress, possibly involving an increased cellular c-di-GMP concentration, induced the CdbA/CsdK1/CsdK2/CdbS system, causing a CsdK1- and CsdK2-dependent increase in CdbS accumulation. Thereby this system accelerates heat stress-induced chromosome mis-organization and cell death. Collectively, this work describes a unique system that contributes to regulated cell death in M. xanthus and suggests a link between c-di-GMP signaling and regulated cell death in bacteria.

Dibenzylideneacetone Induces Apoptosis in Cervical Cancer Cells through Ros-Mediated Mitochondrial Damage

Cervical cancer is a health problem among women worldwide. Considering the limitations of prevention and antineoplastic chemotherapy against cervical cancer, research is needed to discover new, more effective, and safe antitumor agents. In the present study, we investigated the in vitro cytotoxicity of a new synthetic dibenzylideneacetone derived from 1,5-diaryl-3-oxo-1,4-pentadienyl (A3K2A3) against cervical cancer cells immortalized by HPV 16 (SiHa), and 18 (HeLa) by MTT assay. Furthermore, we performed spectrofluorimetry, flow cytometry, and Western blot analyzes to explore the inhibitory mechanism of A3K2A3 in cervical cancer cells. A3K2A3 showed cytotoxic activity against both cell lines. Mitochondrial depolarization and reduction in intracellular ATP levels were observed, which may be dependent on the redox imbalance between increased ROS and reduced levels of the antioxidant defense. In addition, damage to the cell membrane and DNA, and effective blocking of cell division in the G2/M phase were detected, which possibly led to the induction of apoptosis. This result was further confirmed by the upregulation of apoptosis-related proteins Bax, cytochrome C, and caspases 9 and 3. Our results provided the first evidence that A3K2A3 contributes to the suppression of cervical cancer in vitro, showing promise as a possible alternative for the treatment of this cancer.

Tryptophan Availability during Persistence of Chlamydia trachomatis Directly Impacts Expression of Chlamydial Cell Division Proteins.

Chlamydia is an obligate intracellular pathogen with a highly reduced genome devoid of major stress response genes like relA and spoT, which mediate the stringent response. Interestingly, as an intracellular bacterium dependent on its host for nutrients and as a tryptophan (Trp) auxotroph, Chlamydia is very sensitive to Trp starvation, which is induced in vivo by the host cytokine interferon-γ. In response to Trp starvation, Chlamydia enters a viable but nonreplicating state called persistence. A major characteristic of chlamydial persistence is a block in cell division. We hypothesized that cell division is blocked during persistence by the inability to translate Trp-rich cell division proteins. To test this, we first investigated the translation of various cell division proteins under Trp starvation conditions using inducible expression strains. We observed that the Trp-poor protein MurG and the Trp-neutral protein FtsL were still expressed during persistence, while the expression of the Trp-rich proteins Pbp2, RodA, FtsI/Pbp3, and MraY was significantly reduced. As proof of concept for our hypothesis, we compared expression of a wild-type and mutant isoform of RodZ in which its four Trp codons were mutated. These experiments demonstrated that decreased expression of RodZ during persistence was reversed when no Trp was present in the protein, thus directly linking its expression to its Trp content. Together, these experiments indicate that specific cell division proteins are not produced during persistence. For the first time, our data provide a mechanism that explains the inhibition of cell division during chlamydial persistence mediated by Trp starvation.

Design and exploration of neural network microsystem based on SiP

In recent years, microelectronics technology has entered the era of nanoelectronics/integrated microsystems. System in package (SiP) and system on chip (SoC) are two important technical approaches for the realization of microsystems. Deep learning technology based on neural networks is used in graphics and images. Computer vision and target recognition are widely used. The deep learning technology of convolutional neural network is an important research field in the miniaturization and miniaturization of embedded platforms. How to combine the lightweight neural network with the microsystem to achieve the optimal balance of performance, size, and power consumption is a difficult point. This article introduces a micro-system implementation scheme that combines SiP technology and FPGA-based convolutional neural network. It uses Zynq SoC and FLASH and DDR3 memory as the main components, and uses SiP high-density system packaging technology to integrate. PL end (FPGA) design Convolutional Neural Network, convolutional neural network accelerator, adopt the method of convolution multi-dimensional division and cyclic block to design the accelerator structure, design multiple multiplication and addition parallel computing units to provide the computing power of the system. Improving and accelerating perform on the YOLOv2_Tiny model. The test uses the COCO data set as the training and test samples. The microsystem can accurately identify the target. The volume is only 30 × 30 × 1.2 mm. The performance reaches 22.09GOPs and the power consumption is only 0.81 W under the working frequency of 150 MHz. Multi-objective balance (performance, size and power consumption) of lightweight neural network Microsystems has realized.

The life in a gradient: calcium, the lncRNA SPRR2C and mir542/mir196a meet in the epidermis to regulate the aging process.

The turnover of the epidermis beginning with the progenitor cells in the basal layer to the fully differentiated corneocytes is tightly regulated by calcium. Calcium more than anything else promotes the differentiation of keratinocytes which implies the need for a calcium gradient with low concentrations in the stratum basale and high concentrations in the stratum granulosum. One of the hallmarks of skin aging is a collapse of this gradient that has a direct impact on the epidermal fitness. The rise of calcium in the stratum basale reduces cell proliferation, whereas the drop of calcium in the stratum granulosum leads to a changed composition of the cornified envelope. We showed that keratinocytes respond to the calcium induced block of cell division by a large increase of the expression of several miRNAs (hsa-mir542-5p, hsa-mir125a, hsa-mir135a-5p, hsa-mir196a-5p, hsa-mir491-5p and hsa-mir552-5p). The pitfall of this rescue mechanism is a dramatic change in gene expression which causes a further impairment of the epidermal barrier. This effect is attenuated by a pseudogene (SPRR2C) that gives rise to a lncRNA. SPRR2C specifically resides in the stratum granulosum/corneum thus acting as a sponge for miRNAs.

The Chaperonin GroESL Facilitates Caulobacter crescentus Cell Division by Supporting the Functions of the Z-Ring Regulators FtsA and FzlA.

ABSTRACTThe highly conserved chaperonin GroESL performs a crucial role in protein folding; however, the essential cellular pathways that rely on this chaperone are underexplored. Loss of GroESL leads to severe septation defects in diverse bacteria, suggesting the folding function of GroESL may be integrated with the bacterial cell cycle at the point of cell division. Here, we describe new connections between GroESL and the bacterial cell cycle using the model organism Caulobacter crescentus. Using a proteomics approach, we identify candidate GroESL client proteins that become insoluble or are degraded specifically when GroESL folding is insufficient, revealing several essential proteins that participate in cell division and peptidoglycan biosynthesis. We demonstrate that other cell cycle events, such as DNA replication and chromosome segregation, are able to continue when GroESL folding is insufficient. We further find that deficiency of two FtsZ-interacting proteins, the bacterial actin homologue FtsA and the constriction regulator FzlA, mediate the GroESL-dependent block in cell division. Our data show that sufficient GroESL is required to maintain normal dynamics of the FtsZ scaffold and divisome functionality in C. crescentus. In addition to supporting divisome function, we show that GroESL is required to maintain the flow of peptidoglycan precursors into the growing cell wall. Linking a chaperone to cell division may be a conserved way to coordinate environmental and internal cues that signal when it is safe to divide.

Starch Production in Chlamydomonas reinhardtii through Supraoptimal Temperature in a Pilot-Scale Photobioreactor.

An increase in temperature can have a profound effect on the cell cycle and cell division in green algae, whereas growth and the synthesis of energy storage compounds are less influenced. In Chlamydomonas reinhardtii, laboratory experiments have shown that exposure to a supraoptimal temperature (39 °C) causes a complete block of nuclear and cellular division accompanied by an increased accumulation of starch. In this work we explore the potential of supraoptimal temperature as a method to promote starch production in C. reinhardtii in a pilot-scale photobioreactor. The method was successfully applied and resulted in an almost 3-fold increase in the starch content of C. reinhardtii dry matter. Moreover, a maximum starch content at the supraoptimal temperature was reached within 1–2 days, compared with 5 days for the control culture at the optimal temperature (30 °C). Therefore, supraoptimal temperature treatment promotes rapid starch accumulation and suggests a viable alternative to other starch-inducing methods, such as nutrient depletion. Nevertheless, technical challenges, such as bioreactor design and light availability within the culture, still need to be dealt with.

Review of Basic Classes of Dividers Based on Division Algorithm

The electronics world is very well described in two distinct but dependent interdisciplinary areas, namely hardware and software. Arithmetic operations are very vital building blocks of an electronic system. An algorithm is a systematic arrangement that helps develop a sophisticated electronic system, including hardware and software aspects. Addition, subtraction, multiplication, and division are critical elements of arithmetic implementation in the electronic system, but fewer efforts have been made to implement division than other arithmetic operations, even though the number of transistors on a chip is increasing beyond the Moore's law prediction. It is quite complicated to implement arithmetical operations; here, a sophisticated algorithm is essential to successful implementation. Technological upgrades are leading to a new paradigm of applications, where the performance of a division circuit or block is a vital and critical feature of a successful system. The lexicon of algorithms used in the implementation of the division operation in electronics systems is discussed in detail in the present article, which indicates the mathematical formulation, criticality, conversion pattern, hardware requirements, and logic used for conversion. The current report describes the broad classification of dividers into basic classes named digit recurrence, high radix, functional iteration, estimation, a look-up table, and variable latency. It also illustrates that, in practical implementation, many algorithms have been developed that combine one or many classes and are implemented with different hardware architectures. The study indicated the possibility of improving the presently available algorithms or creating a new algorithm to enhance practical implementation.

Modernism in the Case of Cultural Architecture in Yugoslavia

As a result of very strong and organised antifascist resistance on domestic territory during the World War II and historical conditions in the rest of Europe, new established socialist country Yugoslavia on geostrategic games was planned to stay part of the eastern block in the new division of post-war Europe. But just three years after the war Yugoslavian political establishment led by charismatic president Tito, despite the serious threats from USSR and Stalin, he decided to start with their own way of socialism based on self-management with reduced influence of the state into the economy, society and culture. The result was an atypical socialist system for that time, which was very open to the world, but especially to Western Europe and the USA. During the whole history, architecture was always the best representation of historical developments and social circumstances in different civilisations through different periods. Yugoslavian modernist architecture developed by domestic architects, influenced by modernist ideas from Central and Western Europe and with phenomenological support of the state can be considered as an indicator of social and cultural movements during the existence of that avant-garde socialist country from 1945-1990. Through the research of different study cases and examples of architecture from socialist Yugoslavia and studies of relevant scientists from the field of architecture and sociology, as a predominant methodology for this study, relations between architecture and socio-economic and cultural conditions will be investigated. In accordance with the declared ideas for general modernisation of the entire society, modernist architecture in Yugoslavia was widely accepted as a tool for the realisation of proclaimed ideals for open, human oriented and contemporary society. The architecture of cultural buildings was some of the best examples for the mentioned direction in the content, but even more in conceptual and visual expression. The Yugoslavian architecture of the representative cultural centres, museums, libraries and concert halls are some of the most successful realizations of modernism in the region of south east Europe, but even much wider. At the same time, these buildings were witnessing well organized, state supported institutional work that was able to arrange some of the most prominent cultural activities on the highest world level.

Yield of SCN5A sequencing in patients with related phenotypes studied in an inherited cardiovascular diseases unit

Abstract Mutations in SCN5A gene have been associated with different cardiac manifestations, so it is frequently tested in familial cardiovascular diseases. Our objective was to analyze the prevalence of pathogenic mutations (PM) in SCN5A in hereditary cardiovascular diseases and to describe the clinical characteristics of genetic carriers. SCN5A gene (NM_198056.2) was sequenced by NGS in panels of genes directed to each cardiac phenotype. We studied 219 index cases with theses phenotypes: 144 dilated/arrhythmogenic cardiomyopathy (DCM), 34 Brugada syndrome (BS), 19 idiopathic ventricular fibrillation (IVF), 10 long QT syndrome (LQTS), 9 sudden death with nondiagnostic necropsy and 3 advanced conduction system abnormalities. We identified 8 PM in 9 families, two of them have not been previously described: deletion of exons 1–16 of SCN5A and 15_27 in SCN10A and c.2665C>G. The prevalence of PM according to phenotypes was: 3 DCM (2%), 1 IVF (5%), 4 BS (12%) and 1 advanced conduction system abnormalities (33%). Additionally, we identified 4 variants of uncertain pathogenicity, two of them in the same patient with LQTS (compound heterozygosis). The index cases description is developed in Table 1. In our cohort the prevalence of PM in SCN5A is similar to those described in literature. The majority are associated with a combined phenotype (overlap syndrome of cardiac sodium channelopathy) which is characterized by supraventricular and ventricular arrhythmias and conduction system abnormalities, and some of them with DCM. Patients with BS had no additional manifestations, apart from ventricular arrhythmias in follow up. Table 1 Family number SCN5A Mutation Other mutations Sex/Age at diagnosis of index case (years) Phenotype of index case Devices (Age, years) Number of studied relatives (+ Genotype) Phenotypes in the family (Age, years) Family history 1 Deletion in exons 1_16 of SCN5A, y 15_27 of SCN10A SCN5A:c.3068G>T (VUS) Female/38 SCD due to nocturnal VF, Brugada syndrome Secondary prevention ICD (38) 2 (0) – SCD at paternal line 2 c.2254G>A LMNA:c.986G>A (VUS) Female/64 DCM Primary prevention ICD (69) 3 (1) Daughter PM (39) and atrial flutter SCD in first degree family members 3 c.2665C>G – Male/46 AF (27), AVB (36), VF (46) PM (36), secondary prevention ICD (46) 6 (3) Father PM (47) and atrial flutter Paternal grandfather SCD (53), cousin SCD (26) 4 c.2665C>G SCN5A:c.4057G>A (VUS) Male/ 64 DCM, VT, AF, atrial flutter (64) Secondary prevention (64), cardiac resynchronization therapy (68) 15 (7) Sister PM (26) None 5 c.3823G>A – Male/48 BS Primary prevention ICD (48) 0 (0) – SCD. Cousin with BS and ICD. Maternal grandmother with pacemaker. 6 c.4297G>T – Male/42 BS NO 4 (2) Sister Type 2 BS None 7 c.4783G>A – Male/14 Bifascicular heart block (right bundle branch block and left anterior division block), VT, atrial flutter. Primary prevention ICD (15) 3 (0) – None (de novo mutation) 8 c.4876C>T MYH7:c.4763G>A (VUS) Male/38 DCM, AVB, VF Secondary prevention ICD (38) 0 (0) – SCD in sibling (39 years) 9 c.4981G>A – Female/23 BS Primary prevention ICD (25), appropriate therapy in follow up 3 (0) – None (de novo mutation) AF: atrial fibrillation; AVB: atrioventricular block; BS: Brugada syndrome; DCM: dilated cardiomyopathy; ICD: implantable cardioverter defibrillator; PM: pacemaker; SCD: sudden cardiac death; VF: ventricular fibrillation; VT: ventricular tachycardia; VUS: Variant of uncertain significance. Funding Acknowledgement Type of funding source: None

Influence of nutrient status on the biohydrogen and lipid productivity in Parachlorella kessleri: a biorefinery approach.

The commercial reality of microalgal biotechnology for the production of individual bioactives is constrained by the high cost of production and requires a biorefinery approach. In this investigation, we examined the influence of different nutrient deprivation (nitrogen (N), phosphorus (P), sulphur (S) and manganese (Mn)) on growth, chlorophyll a (Chl a), biohydrogen (H2) and fatty acid profiles in Parachlorella kessleri EMCCN 3073 under both aerobic and anaerobic conditions. Anaerobic conditions combined with the nutrient deprivation resulted in cell division blockage, reduction in Chl a and remarkable changes in pH, whereas a significant increase in the H2 production was observed after 24h. The highest cumulative H2 productivity was observed in N-deficient medium (300μL/L, day 9) followed by Mn-deficient medium (250μL/L, day 7). The highest H2 production rate (3.37μL/L/h) was achieved by Mn-deficient medium after 24h. In terms of fatty acid composition, P. kessleri exhibited a differential response to different nutrient stresses. Under aerobic conditions, N-deficient media resulted in the highest lipid content (119% compared to control, day 7), whereas earlier lipid induction at (1-3days) was observed with Mn- and S-deficient media with 18-91% and 25-34% increase, respectively, compared with the replete control. Meanwhile, higher lipid content was observed under anaerobic conditions combined with Mn-, N-, P- and S-deprived media (day 1) with 20%, 13%, 8% and 7% increases respectively compared with the control. This investigation, for the first time clearly, highlights the potential of P. kessleri as a sustainable biorefinery platform, for H2 and fatty acid bio-production under anaerobic conditions. KEY POINTS: • Parachlorella kessleri could provide a future sustainable biorefinery platform. • Nutrient-deprived anaerobic conditions blocked cell growth but differentially induced H2 production. • Nutrient status, under both aerobic/anaerobic conditions, alters lipids and fatty acids profile of P. kessleri. • Nutrient-deprived (N- and Mn-) anaerobic conditions: future biorefinery platform.

CdbA is a DNA-binding protein and c-di-GMP receptor important for nucleoid organization and segregation in Myxococcus xanthus

Cyclic di-GMP (c-di-GMP) is a second messenger that modulates multiple responses to environmental and cellular signals in bacteria. Here we identify CdbA, a DNA-binding protein of the ribbon-helix-helix family that binds c-di-GMP in Myxococcus xanthus. CdbA is essential for viability, and its depletion causes defects in chromosome organization and segregation leading to a block in cell division. The protein binds to the M. xanthus genome at multiple sites, with moderate sequence specificity; however, its depletion causes only modest changes in transcription. The interactions of CdbA with c-di-GMP and DNA appear to be mutually exclusive and residue substitutions in CdbA regions important for c-di-GMP binding abolish binding to both c-di-GMP and DNA, rendering these protein variants non-functional in vivo. We propose that CdbA acts as a nucleoid-associated protein that contributes to chromosome organization and is modulated by c-di-GMP, thus revealing a link between c-di-GMP signaling and chromosome biology.

Morphological Features of the Anther Development in Tomato Plants with Non-Specific Male Sterility.

The study was devoted to morphological and cytoembryological analysis of disorders in the anther and pollen development of transgenic tomato plants with a normal and abnormal phenotype, which is characterized by the impaired development of generative organs. Various abnormalities in the structural organization of anthers and microspores were revealed. Such abnormalities in microspores lead to the blocking of asymmetric cell division and, accordingly, the male gametophyte formation. Some of the non-degenerated microspores accumulate a large number of storage inclusions, forming sterile mononuclear pseudo-pollen, which is similar in size and appearance to fertile pollen grain (looks like pollen grain). It was discussed that the growth of tapetal cells in abnormal anthers by increasing the size and ploidy level of nuclei contributes to this process. It has been shown that in transgenic plants with a normal phenotype, individual disturbances are also observed in the development of both male and female gametophytes. The reason for the developmental arrest of some ovules was the death of endosperm at different stages of the globular embryo. At the same time, noticeable hypertrophy of endothelial cells performing a secretory function was observed. In the ovules of transgenic plants with abnormalities, the endothelium forms a pseudo-embryo instead of the embryo sac, stimulating the development of parthenocarpic fruits. The data obtained in this study can be useful for a better understanding of the genetic and molecular mechanisms of cytoplasmic male sterility and parthenocarpic fruit development in tomatoes.

Molecular Basis and Ecological Relevance of Caulobacter Cell Filamentation in Freshwater Habitats.

All living cells are characterized by certain cell shapes and sizes. Many bacteria can change these properties depending on the growth conditions. The underlying mechanisms and the ecological relevance of changing cell shape and size remain unclear in most cases. One bacterium that undergoes extensive shape-shifting in response to changing growth conditions is the freshwater bacterium Caulobacter crescentus When incubated for an extended time in stationary phase, a subpopulation of C. crescentus forms viable filamentous cells with a helical shape. Here, we demonstrated that this stationary-phase-induced filamentation results from downregulation of most critical cell cycle regulators and a consequent block of DNA replication and cell division while cell growth and metabolism continue. Our data indicate that this response is triggered by a combination of three stresses caused by prolonged growth in complex medium, namely, the depletion of phosphate, alkaline pH, and an excess of ammonium. We found that these conditions are experienced in the summer months during algal blooms near the surface in freshwater lakes, a natural habitat of C. crescentus, suggesting that filamentous growth is a common response of C. crescentus to its environment. Finally, we demonstrate that when grown in a biofilm, the filamentous cells can reach beyond the surface of the biofilm and potentially access nutrients or release progeny. Altogether, our work highlights the ability of bacteria to alter their morphology and suggests how this behavior might enable adaptation to changing environments.IMPORTANCE Many bacteria drastically change their cell size and morphology in response to changing environmental conditions. Here, we demonstrate that the freshwater bacterium Caulobacter crescentus and related species transform into filamentous cells in response to conditions that commonly occur in their natural habitat as a result of algal blooms during the warm summer months. These filamentous cells may be better able to scavenge nutrients when they grow in biofilms and to escape from protist predation during planktonic growth. Our findings suggest that seasonal changes and variations in the microbial composition of the natural habitat can have profound impact on the cell biology of individual organisms. Furthermore, our work highlights that bacteria exist in morphological and physiological states in nature that can strongly differ from those commonly studied in the laboratory.

A code division multiplexing and block classification-based real-time reversible data-hiding algorithm for medical images

This paper proposes a novel reversible data hiding (RDH) scheme for medical image based on block classification and code division multiplexing (CDM) in frequency domain. In this scheme, the original medical image is divided into non-overlapping blocks and classified into texture and smooth groups by calculating the mean square error of each block. The texture blocks are then transformed into the frequency domain with integer-to-integer discrete wavelet transform method, and the secret data are embedded into the detail sub-bands of the chosen texture blocks with CDM-based RDH algorithm. Consequently, the detail information of medical image is clarified and the data-embedding capacity is enlarged. Simultaneously, as the spreading sequences employed for data embedding are orthogonal to each other, when the secret message is repeatedly embedded into the cover image, most of the elements of spreading sequences are mutually canceled, which enables the proposed scheme to obtain high visual quality even at large data-embedding capacities. Moreover, on the receiver side, only the receiver with the correct data-embedding and block classification parameters can reconstruct the secret message and the cover image completely; thus, the security of RDH is guaranteed. Experimental results have demonstrated that the proposed scheme can yield better overall performance than other state-of-the-art RDH schemes on medical images.

Joint Spatial Division and Diversity for Massive MIMO Systems

We propose a downlink beamforming scheme that combines spatial division and orthogonal space-time block coding (OSTBC) in multi-user massive MIMO systems. The beamformer is divided into two parts: a pre-beamforming matrix to separate the users into different beams with no interference between each other, which is designed based on the low rank covariance matrix of the downlink channel, and a linear precoding matrix using partial or even no channel state information (CSI) concatenated by an OSTBC. To construct the pre-beamforming matrix, a simple method that selects columns from DFT matrix is presented. To design the linear precoding matrix with partial CSI of the effective channel after the pre-beamforming, we solve an optimization problem to minimize the pairwise error probability (PEP) of the users under an individual power or sum power constraint, respectively. For the individual power constraint, a semi-definite relaxing (SDR) method with a sufficient condition achieving the globally optimal solution is proposed to provide a performance benchmark. In addition, an efficient iterative successive convex approximation (SCA) method is provided to achieve a suboptimal solution. Furthermore, closed form solutions are derived under some special cases. For the sum power constraint, we consider two different designs, i.e., minimizing the average PEP and minimizing the maximum PEP of all users. We find that both non-convex problems have a similar structure, and proposed a unified SCA-Alternating Direction Method of Multipliers (ADMM) algorithm to handle them. The SCA-ADMM method can be implemented in a parallel manner, and thus is with great efficiency. Simulation results show the efficiency of our proposed JSDD scheme and the optimization method.

Selection of Non-Magnetic Fraction from the Slime Wastes of Metal Production in the Electromagnetic Field

It is proved that the use of a variable inhomogeneous magnetic field, created by the superposition of constant and variable, strongly inhomogeneous fields, is considered to be very promising for the separation of non-magnetic fraction from powders of magnetic materials. This article introduces the effective technology of separation of non-magnetic fraction from the sludge wastes of metal production in the electromagnetic field, which allows to destroy the aggregates, to separate the abrasive and to get products of high purity. A complex on processing of grinding sludge includes the following blocks: the loading block with dispenser; block of preliminary squeezing and washing of DRC; the block of drying; the block of a refinement; the block of division of sludge fractions. Experimental approbation of the proposed technological scheme of sludge separation, which had been carried out on iron ore concentrate of class 63 microns with silica content of 4.57% of the mass, showed that with the field parameters close to the calculated, the magnetic vibrating layer of iron powder PZh-4M has the maximum development; increasing the separation time leads to more efficient separation in the interval of field induction gradient from 550 mT/ m to 610 mT/m.

Expression of a Peptidoglycan Hydrolase from Lytic Bacteriophages Atu_ph02 and Atu_ph03 Triggers Lysis of Agrobacterium tumefaciens.

To provide food security, innovative approaches to preventing plant disease are currently being explored. Here, we demonstrate that lytic bacteriophages and phage lysis proteins are effective at triggering lysis of the phytopathogen Agrobacterium tumefaciens Phages Atu_ph02 and Atu_ph03 were isolated from wastewater and induced lysis of C58-derived strains of A. tumefaciens The coinoculation of A. tumefaciens with phages on potato discs limited tumor formation. The genomes of Atu_ph02 and Atu_ph03 are nearly identical and are ∼42% identical to those of T7 supercluster phages. In silico attempts to find a canonical lysis cassette were unsuccessful; however, we found a putative phage peptidoglycan hydrolase (PPH), which contains a C-terminal transmembrane domain. Remarkably, the endogenous expression of pph in the absence of additional phage genes causes a block in cell division and subsequent lysis of A. tumefaciens cells. When the presumed active site of the N-acetylmuramidase domain carries an inactivating mutation, PPH expression causes extensive cell branching due to a block in cell division but does not trigger rapid cell lysis. In contrast, the mutation of positively charged residues at the extreme C terminus of PPH causes more rapid cell lysis. Together, these results suggest that PPH causes a block in cell division and triggers cell lysis through two distinct activities. Finally, the potent killing activity of this single lysis protein can be modulated, suggesting that it could be engineered to be an effective enzybiotic.IMPORTANCE The characterization of bacteriophages such as Atu_ph02 and Atu_ph03, which infect plant pathogens such as Agrobacterium tumefaciens, may be the basis of new biocontrol strategies. First, cocktails of diverse bacteriophages could be used as a preventative measure to limit plant diseases caused by bacteria; a bacterial pathogen is unlikely to simultaneously develop resistances to multiple bacteriophage species. The specificity of bacteriophage treatment for the host is an asset in complex communities, such as in orchards where it would be detrimental to harm the symbiotic bacteria in the environment. Second, bacteriophages are potential sources of enzymes that efficiently lyse bacterial cells. These phage proteins may have a broad specificity, but since proteins do not replicate as phages do, their effect is highly localized, providing an alternative to traditional antibiotic treatments. Thus, studies of lytic bacteriophages that infect A. tumefaciens may provide insights for designing preventative strategies against bacterial pathogens.