Asymmetric interactions between plants and seed-harvesting ants in a Mediterranean pasture

A four-year study on the interactions between plants and seed-harvesting ants in a Mediterranean pasture is reviewed in this paper. As previously reported in many studies on plant–herbivore interactions, ant–plant relationships are also asymmetric; plants had a larger impact on herbivore dynamics than vice versa. However, the asymmetry did not refer to population dynamics but rather to animal foraging strategies. Ants did not exert a significant influence on vegetation dynamics in terms of plant abundance. The main constraints underlying vegetation change were self-regulation and rainfall. In contrast, the structural characteristics and abundance of vegetation had a significant impact on several important features of food harvesting by ants. This influence was not only associated with their feeding requirements but also with their foraging activities.     

Glial-secreted Netrins regulate Robo1/Rac1-Cdc42 signaling threshold levels during Drosophila asymmetric neural stem/progenitor cell division

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Crucial markers showing the risk of coronary artery disease in obesity: ADMA and neopterin

BackgroundObesity is responsible for high morbidity and mortality, both in developed and developing countries. It is associated with many chronic and metabolic diseases. Asymmetric dimethylarginine (ADMA) has been demonstrated to be a biomarker of endothelial dysfunction in humans and increased ADMA associated with cardiovascular disease (CVD) risk has been reported in many states. Neopterin (NP) produced by monocytes/macrophages in response to stimulation by interferon-gamma (IFN-γ) is emphasized in recent findings. The current study aims to investigate ADMA and NP levels which may assume a role in guiding the early diagnosis of coronary artery disease in obesity.MethodsThis is an original research study in which ADMA and NP levels of 50 patients (25 male/25 female) diagnosed with obesity were compared with those of 30 healthy individuals (15 male/15 female) as control. The high-performance liquid chromatography (HPLC) method was used while determining parameters.ResultsADMA and NP levels in obese individuals were found to be significantly higher than in those enrolled in the control. ADMA values were found to be higher in obese subjects (0.71±0.24 μmol/L) as compared with levels found in healthy subjects (0.58±0.16 μmol/L) (p<0.05). A significant increase of serum neopterin levels was found in obese subjects (8.8±3.5 μmol/L) as compared with controls (4.9±1.69 μmol/L) (p<0.05). Also, there was a strong positive correlation between NP and ADMA values in obese individuals (r=0.954).ConclusionsOur study revealed that obese subjects have higher ADMA and neopterin levels. These results demonstrated that both ADMA and NP levels may be potential risk factors for coronary heart disease in obesity.     

Structural changes in chromosomes driven by multiple condensin motors during mitosis

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Compromising asymmetric stem cell division in Drosophila central brain: Revisiting the connections with tumorigenesis

Asymmetric cell division (ACD) is an essential process during development for generating cell diversity. In addition, a more recent connection between ACD, cancer and stem cell biology has opened novel and highly intriguing venues in the field. This connection between compromised ACD and tumorigenesis was first demonstrated using Drosophila neural stem cells (neuroblasts, NBs) more than a decade ago and, over the past years, it has also been established in vertebrate stem cells. Here, focusing on Drosophila larval brain NBs, and in light of results recently obtained in our lab, we revisit this connection emphasizing two main aspects: 1) the differences in tumor suppressor activity of different ACD regulators and 2) the potential relevance of environment and temporal window frame for compromised ACD-dependent induction of tumor-like overgrowth.     

Helix-sense-selective polymerization of diphenyl-2-pyridylmethyl methacrylate with chiral anionic initiators

Polymerization of diphenyl-2-pyridylmethyl methacrylate was carried out with the complexes of organolithium compounds with 22 chiral ligands. Helix-sense-selectivity of the polymerization was largely affected by a slight structural difference of chiral ligands. (+)-(S)-2-(1-Pyrrolidinylmethyl)pyrrolidine was the most effective ligand in producing a one-handed helical polymer with narrow molecular weight distribution.     

Asymmetric synthesis of N-protected chiral 1-aminoalkylphosphonic acids and synthesis of side chain-functionalized depsiphosphonopeptides.

Optically active 1-aminoalkylphosphonic acid derivatives were synthesized in moderate yields and optical purities via Mannich-type reactions of benzyl carbamate, aldehydes, and optically pure chlorophosphites. Side chain-functionalized depsiphosphonopeptides were also prepared in satisfactory yields directly from one-pot reactions of benzyl carbamate, aldehydes, and diethyl (R,R)-2-chloro-1,3,2-dioxaphospholane-4,5-dicarboxylate.     

The prevention of an anomalous chromatographic behavior and the resulting successful removal of viruses from monoclonal antibody with an asymmetric charge distribution by using a membrane adsorber in highly efficient,anion-exchange chromatography in flow-through mode

Anion exchange (AEX) chromatography in the flow-through mode is a widely employed purification process for removal of process/product-related impurities and exogenous/endogenous viruses from monoclonal antibodies (mAbs). The pH of the mobile phase for AEX chromatography is typically set at half a unit below the isoelectric point (pI) of each mAb (i.e., pI − 0.5) or lower and, in combination with a low ionic strength, these conditions are usually satisfactory for both the recovery of the mAb and removal of impurities. However, we have recently encountered a tight binding of mAb1 to AEX resins under these standard chromatographic conditions. This anomalous adsorption behavior appears to be an effect of the asymmetric charge distribution on the surface of the mAb1. We found that mAb1 did not bind to the AEX resins if the mobile phase has a much lower pH and higher ionic strength, but those conditions would not allow adequate virus removal. We predicted that the use of membrane adsorbers might provide effective mAb1 purification, since the supporting matrix has a network structure that would be less susceptible to interactions with the asymmetric charge distribution on the protein surface. We tested the Natriflo HD-Q AEX membrane adsorber under standard chromatographic conditions and found that mAb1 flowed through the membrane adsorber, resulting in successful separation from murine leukemia virus. This AEX membrane adsorber is expected to be useful for process development because mAbs can be purified under similar standard chromatographic conditions regardless of their charge distributions.     

Asymmetric cell division from a cell to cells: Shape,length, and location of polarity domain

Asymmetric cell division is one of the most elegant biological systems by which cells create daughter cells with different functions and increase cell diversity. In particular, PAR polarity in the cell membrane plays a critical role in regulating the whole process of asymmetric cell division. Numerous studies have been conducted to determine the underlying mechanism of PAR polarity formation using both experimental and theoretical approaches in the last 10 years. However, they have mostly focused on answering the fundamental question of how this exclusive polarity is established but the precise dynamics of polarity domain have been little notified. In this review, I focused on studies on the shape, length, and location of PAR polarity from a theoretical perspective that may be important for an integrated understanding of the entire process of asymmetric cell division.