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The outer membrane of gram-negative bacteria is a barrier to chemical and physical stress. Phospholipid transport between the inner and outer membranes has been an area of intense investigation and, in E. coli K-12, it has recently been shown to be mediated by YhdP, TamB, and YdbH, which are suggested to provide hydrophobic channels for phospholipid diffusion, with YhdP and TamB playing the major roles. However, YhdP and TamB have different phenotypes suggesting distinct functions. It remains unclear whether these functions are related to phospholipid metabolism. We investigated a synthetic cold sensitivity caused by deletion of fadR, a transcriptional regulator controlling fatty acid degradation and unsaturated fatty acid production, and yhdP, but not by ΔtamB ΔfadR or ΔydbH ΔfadR. Deletion of tamB recuses the ΔyhdP ΔfadR cold sensitivity further demonstrating the phenotype is related to functional diversification between these genes. The ΔyhdP ΔfadR strain shows a greater increase in cardiolipin upon transfer to the non-permissive temperature and genetically lowering cardiolipin levels can suppress cold sensitivity. These data also reveal a qualitative difference between cardiolipin synthases in E. coli, as deletion of clsA and clsC suppresses cold sensitivity but deletion of clsB does not. Moreover, increased fatty acid saturation is necessary for cold sensitivity and lowering this level genetically or through supplementation of oleic acid suppresses the cold sensitivity of the ΔyhdP ΔfadR strain. Together, our data clearly demonstrate that the diversification of function between YhdP and TamB is related to phospholipid metabolism. Although indirect regulatory effects are possible, we favor the parsimonious hypothesis that YhdP and TamB have differential phospholipid-substrate transport preferences. Thus, our data provide a potential mechanism for independent control of the phospholipid composition of the inner and outer membranes in response to changing conditions based on regulation of abundance or activity of YhdP and TamB. Author summary: Gram-negative bacteria possess a highly impermeable outer membrane, which protects against environmental stress and antibiotics. Outer membrane phospholipid transport remained mysterious until YhdP, TamB, and YdbH were recently implicated in phospholipid transport between the inner and outer membranes of E. coli. Similar roles for YhdP and/or TamB have been suggested in both closely and distantly related gram-negative bacteria. Here, given the transporters' apparent partial redundancy, we investigated functional differentiation between YhdP and TamB and its potential link to phospholipid metabolism. Our data demonstrate YhdP and TamB have differential involvement with fatty acid and phospholipid metabolism. Transport of increased levels of cardiolipin and saturated phospholipids in the absence of YhdP and presence of TamB at a non-permissive temperature is lethal. These data clearly demonstrate that the diversification of function between YhdP and TamB is related to phospholipid metabolism. One possible mechanism for this differentiation would be differential phospholipid transport preference between YhdP and TamB. Diversification of function between YhdP and TamB roles in phospholipid metabolism provides a potential mechanism for regulation of phospholipid composition, and possibly the mechanical strength and permeability of the outer membrane, and so the cell's intrinsic antibiotic resistance, in changing environmental conditions. [ABSTRACT FROM AUTHOR]

To understand life-long neurogenesis in the dentate gyrus (DG), characterizing dentate neural stem cells and the signals controlling their development are crucial. In the present study, we show that bone morphogenic protein (Bmp) signaling is a critical regulator of embryonic dentate development, required for initiating neurogenesis in embryonic DG progenitors and required for the establishment of dentate neural stem cells postnatally. We tested the hypothesis that Bmp signaling regulates dentate development in part by controlling the expression of Lef1, a Wnt responsive transcription factor expressed in dentate stem cells and absolutely required for dentate granule cell production. Bmp activation through the Acvr1 receptor induced Lef1 expression and neurogenesis in the embryonic DG. Ectopic expression of Bmp7 in the embryonic midline increased DG neurogenesis and inhibition of local Bmp signaling decreased embryonic DG neurogenesis. Mice with selective loss of Bmp expression due to defective meningeal development or with selective conditional deletion of meningeal Bmp7 also have dentate developmental defects. Conditional deletion of Activin receptor type I (Acvr1) or Smad4 (a downstream target nuclear effector of Bmp signaling) in DG neural stem cells resulted in defects in the postnatal subgranular zone and reduced neurogenesis. These results suggest that Acvr1-mediated meningeal Bmp signaling regulates Lef1 expression in the dentate, regulating embryonic DG neurogenesis, DG neural stem cell niche formation, and maintenance.

Natural disasters and warfare lead to the destruction of city buildings and infrastructure, leaving large numbers of people homeless. The rebuilding of destroyed cities needs to be carried out promptly while maintaining a balance between construction quality and duration. Rework due to defects and the lengthy approval of non-conformances significantly increases the duration of construction. This study aimed to develop a decision support system to fix or negotiate strategies to address construction defects, depending on their level of risk. The paper addresses the following objectives: classifying defects by the quality of construction that they affect; building a tree of construction defect risks; and developing an artificial neural network (ANN) to assess the defect risk. The weights of the links are represented by posterior probabilities of damage calculated using the Bayes' theorem in the pre-training stage. The ANN has been adapted to cast-in-place reinforced concrete structures. When training the resulting ANN on a sample of precedents, the test sample demonstrated convergence and low errors. The resulting model will accelerate construction by automating assessments of defect severity and reducing the time spent on reworking defects with low quality risk. [ABSTRACT FROM AUTHOR]

Forensic examination is one of the most reliable means of proof in civil, criminal, administrative and arbitration proceedings. There are many different examinations that can be divided into groups. One of such types is the forensic land expertise. Forensic land expertise is an analysis, a study conducted by specialists in the field of geodesy and cadastre of real estate objects (cadastral engineers), land management materials and title documents for a land plot with actual land use. The article considers an example from the real practice of conducting a forensic land expertise. For the expertise, the expert independently conducted a geodetic survey. The importance of land management expertise, as well as knowledge of an expert in the field of land and civil law, is noted. The problem of the lack of a developed methodology for conducting a land surveying is revealed. To solve this problem, stages of work were identified, and a version of methodological recommendations was proposed.

To understand life-long neurogenesis in the dentate gyrus (DG), characterizing dentate neural stem cells and the signals controlling their development are crucial. In the present study, we show that bone morphogenic protein (Bmp) signaling is a critical regulator of embry-onic dentate development, required for initiating neurogenesis in embryonic DG progenitors and required for the establishment of dentate neural stem cells postnatally. We tested the hypothesis that Bmp signaling regulates dentate development in part by controlling the expression of Lefl, a Wnt responsive transcription factor expressed in dentate stem cells and absolutely required for dentate granule cell production. Bmp activation through the Acvrl receptor induced Lefl expression and neurogenesis in the embryonic DG. Ectopic expression of Bmp7 in the embryonic midline increased DG neurogenesis and inhibition of local Bmp signaling decreased embryonic DG neurogenesis. Mice with selective loss of Bmp expression due to defective meningeal development or with selective conditional deletion of meningeal Bmp7 also have dentate developmental defects. Conditional deletion of Activin receptor type I (Acvrl) or Smad4 (a downstream target nuclear effector of Bmp signaling) in DG neural stem cells resulted in defects in the postnatal subgranular zone and reduced neurogenesis. These results suggest that Acvrl-mediated meningeal Bmp signaling regulates Lefl expression in the dentate, regulating embryonic DG neurogenesis, DG neural stem cell niche formation, and maintenance. [ABSTRACT FROM AUTHOR]

Magnetic contrast agents are widely used in magnetic resonance imaging in order to significantly change the signals from the regions of interest in comparison with the surrounding tissue. Despite a high variety of single-mode T1 or T2 contrast agents, there is a need for dual-mode contrast from the one agent. Here, we report on the synthesis of magnetic submicron carriers, containing Fe3O4 nanoparticles in their structure. We show the ability to control magnetic resonance contrast by changing not only the number of magnetite nanoparticles in one carrier or the concentration of magnetite in the suspension but also the structure of the core–shell itself. The obtained data open up the prospects for dual-mode T1/T2 magnetic contrast formation, as well as provides the basis for future investigations in this direction. [ABSTRACT FROM AUTHOR]

The outer membrane of Gram-negative bacteria is a barrier to chemical and physical stress. Phospholipid transport between the inner and outer membranes has been an area of intense investigation and, in E. coli K-12, it has recently been shown to be mediated by YhdP, TamB, and YdbH, which are suggested to provide hydrophobic channels for phospholipid diffusion, with YhdP and TamB playing the major roles. However, YhdP and TamB have different phenotypes suggesting distinct functions. We investigated these functions using synthetic cold sensitivity (at 30 °C) caused by deletion of yhdP and fadR , a transcriptional regulator controlling fatty acid degradation and unsaturated fatty acid production, but not by Δ tamB Δ fadR or Δ ydbH Δ fadR ,. Deletion of tamB suppresses the Δ yhdP Δ fadR cold sensitivity suggesting this phenotype is related to phospholipid transport. The Δ yhdP Δ fadR strain shows a greater increase in cardiolipin upon transfer to the non-permissive temperature and genetically lowering cardiolipin levels can suppress cold sensitivity. These data also reveal a qualitative difference between cardiolipin synthases in E. coli , as deletion of clsA and clsC suppresses cold sensitivity but deletion of clsB does not despite lower cardiolipin levels. In addition to increased cardiolipin, increased fatty acid saturation is necessary for cold sensitivity and lowering this level genetically or through supplementation of oleic acid suppresses the cold sensitivity of the Δ yhdP Δ fadR strain. Although indirect effects are possible, we favor the parsimonious hypothesis that YhdP and TamB have differential substrate transport preferences, most likely with YhdP preferentially transporting more saturated phospholipids and TamB preferentially transporting more unsaturated phospholipids. We envision cardiolipin contributing to this transport preference by sterically clogging TamB-mediated transport of saturated phospholipids. Thus, our data provide a potential mechanism for independent control of the phospholipid composition of the inner and outer membranes in response to changing conditions.