Days Of Confrontations Research Articles

Diversity and functional assessment of indigenous culturable bacteria inhabiting fine-flavor cacao rhizosphere: Uncovering antagonistic potential against Moniliophthora roreri

The Peruvian Amazonian native cacao faces ongoing challenges that significantly undermine its productivity. Among them, frosty pod rot disease and cadmium accumulation result in losses that need for effective and environmentally safe strategies, such as those based on bacteria. To explore the biological resources in the cacao soil, a descriptive study was conducted to assess the diversity of culturable bacteria across three production districts in the Amazonas region: La Peca, Imaza, and Cajaruro. The study also focused on the functional properties of these bacteria, particularly those related to the major issues limiting cacao cultivation. For this purpose, 90 native bacterial isolates were obtained from the cacao rhizosphere. According to diversity analysis, the community was composed of 19 bacterial genera, with a dominance of the Bacillaceae family and variable distribution among the districts. This variability was statistically supported by the PCoA plots and is related to the pH of the soil environment. The functional assessment revealed that 56.8% of the isolates showed an antagonism index greater than 75% after 7 days of confrontation. After 15 days of confrontation with Moniliophthora roreri, 68.2% of the bacterial population demonstrated this attribute. This capability was primarily exhibited by Bacillus strains. On the other hand, only 4.5% were capable of removing cadmium, highlighting the biocontrol potential of the bacterial community. In addition, some isolates produced siderophores (13.63%), solubilized phosphate (20.45%), and solubilized zinc (4.5%). Interestingly, these traits showed an uneven distribution, which correlated with the divergence found by the beta diversity.Our results revealed a diverse bacterial community inhabiting the Amazonian cacao rhizosphere, showcasing crucial functional properties related to the biocontrol of M. roreri. The information generated serves as a significant resource for the development of further biotechnological tools that can be applied to native Amazonian cacao.

In vitro inhibition of bacteria against Fusarium oxysporum f. sp. cubense race 2

There are three races of Fusarium oxysporum f. sp. cubense (Foc) that affect bananas and plantains, though the Cavendish group banana cultivars are resistant to Foc race 1 (FocR1) and Foc race 2 (FocR2). However, there are no effective control methods for the Tropical Race 4 (R4T). The foregoing makes it necessary to generate biological control strategies for FocR2 fungal model that is present in Mexico, forecasting the potential introduction of FocR4T into our country. In vitro inhibition was evaluated of bacterial strains Bacillus subtilis (BASU), B. velezensis (BAVE), and B. sonorensis (BASO) against three isolates of FocR2 (MIC17188, MIC17191 and MIC17192), obtained from plant samples collected in three banana production sites in the states of Puebla, Michoacán and Oaxaca. At 14 days, the strain BASU had in average high inhibition (55.1%) in comparison to BAVE and BASO strains (45.8 and 21.7%, respectively) against the three fungal strains mentioned before. In addition, the in vitro inhibition of Paenibacillus sp. (BSP 1.1) and Serratia sp. (AC35) was also evaluated by considering three pre-inoculation timings; the strain BSP1.1 showed high inhibition (80.1%) when pre-inoculated individually seven days before the fungus and at seven days of confrontation.

Two Novel Bacillus Strains (subtilis and simplex Species) with Promising Potential for the Biocontrol of Zymoseptoria tritici, the Causal Agent of Septoria Tritici Blotch of Wheat.

Two novel Algerian field-collected isolates were selected for their antifungal activity against Zymoseptoria tritici (teleomorph Mycosphaerella graminicola). The novel strains, termed Alg.24B1 and Alg.24B2, were identified as Bacillus subtilis and Bacillus simplex since their respective nucleotide sequences of the 16S rRNA gene were 100% and 99.93% identical to those of B. subtilis and B. simplex, respectively. The antifungal activities of Alg.24B1 and Alg.24B2 were evaluated by the well diffusion method and compared to those of other Bacillus species. The maximum activity was obtained after two days of confrontation of the bacterial strain supernatants with the fungus for Alg.24B1 and three days for Alg.24B2. Furthermore, the metabolites responsible for the antifungal activity of both strains were detected by the investigation of either gene presence (PCR) or molecule production (activity detection of lytic enzymes and HPLC detection of lipopeptides). Overall, this study showed that in addition to their ability to produce lytic enzymes (protease and β-glucanase), both strains coproduce three types of lipopeptides viz. surfactin, iturin, and fengycin. Thus, the biofungicide activity of both strains may be a result of a combination of different mechanisms. Therefore, they had a great potential to be used as biocontrol agents to effectively manage septoria tritici blotch of wheat (STB).

Cytokine Production by Splenic Cells in C57BL/6J Mice with Depression-Like Behavior Depends on the Duration of Social Stress.

We studied the influence of depression-like behavior developed in C57BL/6J mice under conditions of social stress of different duration on cytokine production by splenic cells. Imbalance of the pro- and anti-inflammatory cytokines was detected at the early stage of depression-like behavior (10-day experience of defeats): increased production of proinflammatory IL-2 and IL-6 cytokines along with a decrease in anti-inflammatory IL-10 level; the levels of IL-1β, TNFα, IFNγ, and IL-4 remained unaffected. At later terms (20 days of confrontations), we revealed more pronounced changes in spontaneous production of proinflammatory cytokines that were not detected after shorter social stress. These findings suggest that cytokine profile depends on duration of social stress. Possible mechanisms of cytokine production during formation of depression-like state are discussed.

Greece and FYROM: the dynamics of economic relations

Economic relations between Greece and the Former Yugoslav Republic of Macedonia (FYROM) have come a long way since the challenging early days of confrontation and non‐recognition. This article analyzes the three main components of this dynamic and mutually beneficial relationship: the official government policy regarding FYROM (the Greek Plan for the Economic Reconstruction of the Balkans); commercial/trade relations; and Greek investment in FYROM. Finding a lasting solution to the question of FYROM’s name has taken on a new urgency in light of NATO’s enlargement and FYROM’s desire to join the organization; it remains to be seen whether the momentum built over the past decade can be maintained or whether economic relations will suffer as a result of renewed political tension and diplomatic roadblocks.

Decrease of κ-opioid receptor mRNA level in ventral tegmental area of male mice after repeated experience of aggression

Brain opioid systems have been implicated in the regulation of social interaction, including agonistic behaviour. κ-Opioid receptor B and C mRNA levels were decreased in the ventral tegmental area but not in the nucleus accumbens in male mice with repeated experience of social victories (winners), but not in mice after social defeats (losers) after 10 but not 20 days of confrontations. μ-Opioid receptor mRNA levels were not changed.

Nature of the distribution of serotonin and a serotonin metabolite in brain structures and the development of immunosuppression in submissive mice.

Studies of C57BL/6J mice with acquired submissive behavior in a sensory contact model demonstrated increases in serotonin (5-HT) levels in the amygdaloid complex, hippocampus, the dopaminergic nuclei A11, A10, and A9, and in the caudate nucleus and hypothalamus, compared with controls, after 10 and 20 days of confrontations. Levels of the 5-HT metabolite 5-hydroxyindoleacetic acid (5-HIAA) in most structures were significantly higher after 20 days of confrontations than after 10 days. Increases in the 5-HIAA/5-HT ratio in the cervical nuclei of the midbrain, nucleus accumbens, A9, and hypothalamus as compared with controls were seen in mice with 10 and 20 days of confrontations. Immunization of mice on days 10 and 20 of confrontations showed suppression of immune responses as compared with controls, while immune measures reached control values by 40 days of experience of defeat. Thus, experience of 10 days of defeat led to immunosuppression on a background of activation of the 5-HT system in a series of brain structures: the cervical nuclei of the midbrain, the nucleus accumbens, and A9. As confrontations continued, there were decreases in the 5-HIAA/5-HT ratio on these structures, along with a tendency for immune responses to increase.

The effect of different psychological profiles and timings of stress exposure on humoral immune response

The aim of this study was to analyse the effects of different timings of stress exposure on humoral immune response in mice previously distinguished by their own psychological profile. The Swiss mice were submitted to two different protocols of social confrontation, based on the timing of stress exposure in relation to an immune challenge: animals socially confronted daily for 2 weeks (SINT) and another group confronted daily for 3 weeks (LINT). Control groups were individually housed in a different room. All groups were intraperitoneally injected with sheep red blood cells (SRBC). The SINT group was challenged on the 1st and 7th days of confrontation, whereas the LINT group was challenged on the 7th and 14th days. Two days prior to the period of social conflict, the animals were tested in the elevated plus-maze (PM). The SINT protocol caused a more depressed primary immune response in the submissive mice than that observed in the dominants. The LINT protocol induced a marked increase in the primary immune response, which was more evident in the dominant mice, whilst no changes were observed in the secondary immune response. In the control and dominant groups, the correlation analysis attributed a higher anti-SRBC titre to the more anxious animals; by contrast, higher anti-SRBC titres were found in the less anxious submissive mice. These studies show that different physiological and behavioural adaptations to environmental demands over time, as well as different psychological profiles, constitute important factors to a better understanding of neuro-immune interactions.

Brain content of 5-hydroxytryptamine and 5-hydroxyindoleacetic acid and immune response in aggressive C57Bl/6J mice

Catabolism of 5-hydroxytryptamine in the midbrain raphe nuclei of aggressive C57Bl/6J mice increased after 10 and 20 days of confrontations. Both catabolism and concentration of 5-hydroxytryptamine increased in the dopaminergic nuclei A11, A10, A9, and in the amygdala. The level of 5-hydroxyindoleacetic acid in the A9 and raphe nuclei decreased after 20 days of confrontations, which coincided with manifestation of the immune response.

Effects of DFMO on glioma cell proliferation, migration and invasion in vitro.

The polyamine inhibitor DL-alpha-difluoromethylornithine (DFMO) is a specific irreversible inhibitor of ornithine decarboxylase which is a rate-limiting enzyme in the polyamine bio-synthesis pathway. The present study describes the effects of DFMO on glioma cell proliferation, migration and invasion using multicellular spheroids from three glioma cell lines (GaMg, U-251 Mg and U-87 Mg). 10 mM DFMO reduced cell migration in the three cell lines by about 30-50%. 1 mM putrescine, added together with DFMO inhibited the DFMO effect. A stronger effect was observed in the growth assay where 10 mM DFMO reduced the spheroid growth, for all cell lines, by 90%. This effect was also reversed by adding 1 mM of putrescine. In vitro tumor cell invasion experiments indicated after 3 days of confrontation, an extensive invasion also after 10 mM DFMO treatment. The brain aggregate volumes were reduced to about the same extent as in the absence of drug, suggesting essentially no effects of DFMO on the invasive process. It is concluded that the tumor spheroids retained their ability to invade normal brain tissue even after DFMO exposure. However, DFMO inhibited spheroid growth and cell migration which supports the notion that cell growth, migration and invasion are biological properties that are not necessarily related to each other.

The politics of space: a history of U.S.-Soviet/Russian competition and cooperation in space

Introduction: International Space PolicyA Paradigm for Intergovernmental Relations The Origins of Space Policy: A Reflection and an Instrument of Foreign and Domestic Interests Early Days of Confrontation and Attempts at Cooperation The Context of Competition and Cooperation in Space: Overall U.S.-Soviet Relations and the American and Soviet Space PrograMs. Cooperation Come and Gone: The 1975 Apollo-Soyuz Test Project and the Subsequent Souring of Superpower Relations A Confluence of U.S. and Soviet/Russian Interests in Space: Cooperation as the Cold War Ends Obstacles to Cooperation in Space, PostCold War: A Nation in Disarray Obstacles to Cooperation in Space, PostCold War: International Barriers, New and Old The Market Bridges the Gap: Commercial Space Cooperation Conclusion: The Space Age Outlives the Cold War