Successful Defense Research Articles

Biological effects of oomycetes elicitins

Successful plant defence responses to pathogen challenges are based on fast and specific pathogen recognition and plant reaction mechanisms. Elicitins, proteinaceous elicitors secreted by the Phytophthora and Pythium species, were first described in Phytophthora culture filtrates as proteins able to induce a hypersensitive response (HR) and resistance in tobacco at low concentrations. Later, they were classified as microbial-associated molecular patterns (MAMPs) able to induce defences in a variety of plant species. In this review, we present a comprehensive summary of the actual knowledge on the representative elicitins and their structure, perception and activation of plant signalling pathways. The current research of elicitins has been focused on a detailed understanding of the molecular mechanisms of the elicitin recognition by plant cells. Moreover, the possibility of elicitin involvement in the establishment and enhancement of plant host resistance to a broad spectrum of pathogens has been intensively studied.

Prey density affects predator foraging strategy in an Antarctic ecosystem.

Studying the effects of prey distribution on predator behavior is complex in systems where there are multiple prey species. The role of prey density in predator behavior is rarely studied in closed ecosystems of one predator species and one prey species, despite these being an ideal opportunity to test these hypotheses. In this study, we investigate the effect of prey density on the foraging behavior of a predatory species in an isolated Antarctic ecosystem of effectively a single predatory species and a single prey species. We use resource selection models to compare prey density in areas utilized by predators (obtained from fine‐scale GPS telemetry data) to prey density at randomly generated points (pseudoabsences) throughout the available area. We demonstrate that prey density of breeding Antarctic petrels (Thalassoica antarctica) is negatively associated with the probability of habitat use in its only predator, the south polar skua (Catharacta maccormicki). Skuas are less likely to utilize habitats with higher petrel densities, reducing predation in these areas, but these effects are present during chick rearing only and not during incubation. We suggest that this might be caused by successful group defense strategies employed by petrel chicks, primarily spitting oil at predators.

Monetary Policy in a Fixed Exchange Rate Regime: Structural Vector Autoregressions with Jumps

This paper evaluates monetary policy effects in a fixed exchange rate regime. A fixed exchange rate regime sometimes suffers from turbulence, owing to speculative attacks or other factors that significantly change the expectations of maintaining such a regime. We, therefore, develop a vector autoregression model with a jump processes to evaluate monetary policy in both tranquil and turbulent states. We find that a contractionary monetary policy shock in the tranquil period only affects the exchange rate in the very short run. Nonetheless, the shock significantly reduces the price level and industrial production, especially for a credible peg with a wider band. During the turbulent period, the exchange rate is kept stable for one quarter when facing the same shock—while industrial production drops significantly. The findings, also shed light on the cost of successful defense of speculative attacks.

Underlying structure in the dynamics of chase and escape interactions

Chase and escape behaviors are important skills in many sports. Previous studies have described the behaviors of the attacker (escaper) and defender (chaser) by focusing on their positional relationship and have presented several key parameters that affect the outcome (successful attack or defense). However, it remains unclear how each individual agent moves, and how the outcome is determined in this type of interaction. To address these questions, we constructed a chase and escape task in a virtual space that allowed us to manipulate agents’ kinematic parameters. We identified the basic strategies of each agent and their robustness to changes in their parameters. Moreover, we identified the determinants of the outcome and a geometrical explanation of their importance. Our results revealed the underlying structure of a simplified human chase and escape interaction and provided the insight that, although each agent apparently moves freely, their strategies in two-agent interactions are in fact rather constrained.

The multifaceted immune regulation of bladder cancer.

Bladder cancer is an important public health concern owing to its prevalence, high recurrence risk and treatment failures. Maintaining the equilibrium between prompt and effective immunity and an excessive and protracted immune response is critical for successful immune defence. This delicate balance is ensured by intrinsic or extrinsic immunoregulatory mechanisms. Intrinsic control of immune cell activation is mediated by stimulatory and inhibitory receptors expressed on the effector cell itself, whereas extrinsic control is mediated via other immune cells by cell-cell contact and/or secretion of inhibitory factors. Tumours can exacerbate these immunosuppressive pathways, fostering a tolerant microenvironment. These mechanisms have previously been poorly described in urothelial carcinoma, but a growing body of evidence highlights the key role of immune regulation in bladder cancer. This process includes immune checkpoints (mostly programmed cell death 1 (PD-1) and programmed cell death 1 ligand 1 (PD-L1)), as well as regulatory T cells, myeloid-derived suppressor cells, tumour-associated macrophages and type 2 innate and adaptive lymphocytes. For each component, quantitative and qualitative alterations, clinical relevance and potential targeting strategies are currently being explored. An improved understanding of immune regulation pathways in bladder cancer development, recurrence and progression will help in the design of novel diagnostic and prognostic tools as well as treatments.

Aggression towards shared enemies by heterospecific and conspecific cichlid fish neighbours

Successful territory defence is a prerequisite for reproduction across many taxa, and often highly sensitive to the actions of territorial neighbours. Nevertheless, to date, assessments of the significance of the behaviour of heterospecific neighbours have been infrequent and taxonomically restricted. In this field study, I examined the importance of both heterospecific and conspecific neighbours in a biparental fish, the convict cichlid, Amatitlania siquia. This was done by assessing the colonisation rates of vacant territories, the rates of aggression by the territory holders, and the overall rates of aggression towards intruders, in treatments that controlled the proximity of both neighbour types. Convict cichlid pairs colonised vacant nesting resources (territory locations) at similar rates independent of the proximity of heterospecific (moga, Hypsophrys nicaraguensis) or conspecific neighbours. However, a model of sympatric cichlid intruder was subjected to considerably higher overall levels of aggression when mogas were nearby. In contrast, the proximity of conspecifics did not have a significant effect on the overall aggression towards the intruder. These results suggest that previously demonstrated higher survival of convict cichlid broods in close proximity of mogas may be driven by aggression towards shared enemies. No conclusive evidence was found regarding whether mogas also influence convict cichlids’ investment into anti-intruder aggression: the results show a marginally non-significant trend, and a moderately large effect size, to the direction of a lower investment in mogas’, but not conspecifics’, proximity. More generally, heterospecific neighbours may provide protective benefits in a wider range of ecological settings than commonly considered.

Executive Prerogatives in the Legislative Process and Democratic Stability: Evidence from Non-Presidential Systems

In their seminal Presidents and Assemblies, Shugart and Carey regard executive prerogatives over legislation as a potential threat to democratic stability. This article asks whether this claim is also valid beyond presidential systems. A long-term analysis of four cases (Britain, France, Sweden and Germany) over the 1866–2015 period leads to three preliminarily conclusions. First, executive prerogatives – the veto, privileges in the introduction of certain pieces of legislation and decree powers – can also be found in (emerging) parliamentary and semi-presidential systems. Second, even legislatures in non-presidential systems are able to balance the representativeness and efficiency of legislation. Third, there is evidence that the origins of this ability lie in the occurrence of and successful defences against vital threats to legislative democracy. Taken together, these findings suggest that executive prerogatives over legislation are not a problem (as envisaged by Shugart and Carey) but a potential solution with respect to democratic stability.

З ВІДДАНІСТЮ СВОЇЙ СПРАВІ, З ЛЮБОВ’Ю ДО ЛЮДЕЙ ТА З ІСКРОЮ ДОБРА У СЕРЦІ

З ВІДДАНІСТЮ СВОЇЙ СПРАВІ, З ЛЮБОВ’Ю ДО ЛЮДЕЙ ТА З ІСКРОЮ ДОБРА У СЕРЦІ

La defensa de Santiago de Cuba al ataque de Vernon de 1741: Principios de fortificación para la guerra en el Caribe

En julio de 1741, el vicealmirante Edward Vernon, poco después del desastre de Cartagena, dirigirá sus fuerzas hacia Santiago de Cuba, gobernada entonces por el coronel Francisco Cagigal de la Vega, quien con anterioridad al estallido de la guerra dispuso los preparativos para su fortificación y defensa. En este estudio nos proponemos documentar la labor que en este ámbito desarrolló el ingeniero francés Francisco de Langle, a fin de analizar y poner en valor su concepto de fortificación para la guerra en el Caribe, que resultará clave para el éxito de esta empresa.

Donald Trump’s Administration Confronting Missile Defence: Key Challenges and Probabilistic Overview

The text describes main US missile defence efforts in the first years of D. Trump’s administration. The analysis of current aspects of BMD (Ballistic Missile Defence) deployments is enhanced by probability analysis examining missile defence reliability. Donald Trump took office in the time of increased military competition between the West and Russia and a dangerous regional crisis related to North Korean nuclear arsenal and its ballistic tests. BMD appeared to bring additional chances to US deterrence options in regional scale, allowing more successful first strike or active defence posture. Notably, D. Trump’s administration managed to raise defence expenditures including BMD spending.

Novel Vaccine Adjuvants: Exploring the Potential of Rexinoids to Influence Effector T Cell Homing to Mucosal Sites

Abstract Vaccines are the most successful defense against infectious diseases. Effective vaccines must target induced immune responses to areas of pathogen entry, a primary site being mucosal surfaces. Certain vitamins can directly impact immune cell migration, indicating potential to function as an adjuvant. We previously showed that all-trans retinoic acid (ATRA), the biologically active form of vitamin A, modifies gut-homing receptor expression on effector T cells upon binding to the retinoic acid receptor (RAR), which joins with the retinoid X receptor (RXR) to function. Giving ATRA during vaccination also resulted in enhanced mucosal protection following viral challenge in murine models. While promising, certain factors limit adding ATRA to a vaccine, including its instability and poor solubility. Rexinoids, synthetic ligands for the RXR, could mimic or better ATRA immune effects by enhancing RAR-mediated transcription. Their improved stability and solubility also allows a greater potential for clinical use. Here we explored the ability of different rexinoids to program effector T cell expression of gut-homing receptors CCR9, α4β7, and CD103. Naïve T cells from transgenic mice were activated with peptide and set concentration of each rexinoid. Flow cytometry showed increased expression of gut-homing receptors in the presence of select rexinoids, indicating their ability to act as an ATRA mimic. A cooperative relationship was also seen between other rexinoids and ATRA as co-culturing with suboptimal doses of each showed enhanced receptor expression, suggesting these rexinoids could potentially act with ATRA normally found in serum. Overall, our findings support the prospective use of rexinoids as adjuvants during vaccination.

A type III-A CRISPR-Cas system employs degradosome nucleases to ensure robust immunity.

CRISPR-Cas systems provide sequence-specific immunity against phages and mobile genetic elements using CRISPR-associated nucleases guided by short CRISPR RNAs (crRNAs). Type III systems exhibit a robust immune response that can lead to the extinction of a phage population, a feat coordinated by a multi-subunit effector complex that destroys invading DNA and RNA. Here, we demonstrate that a model type III system in Staphylococcus epidermidis relies upon the activities of two degradosome-associated nucleases, PNPase and RNase J2, to mount a successful defense. Genetic, molecular, and biochemical analyses reveal that PNPase promotes crRNA maturation, and both nucleases are required for efficient clearance of phage-derived nucleic acids. Furthermore, functional assays show that RNase J2 is essential for immunity against diverse mobile genetic elements originating from plasmid and phage. Altogether, our observations reveal the evolution of a critical collaboration between two nucleic acid degrading machines which ensures cell survival when faced with phage attack.

Informing sustainable building design

PurposeIn recent decades there has been a focus on reducing the overall emissions from the built environment, which increases the complexity of the building design process. More specialized knowledge, a greater common understanding and more cooperation between the stakeholders are required. Interdisciplinary design teams need simple and intuitive means of communication. Architects and engineers are starting to increase their focus on improving interdisciplinary communication, but it is often unclear how to do so. The purpose of this paper is to define the impact of visually communicating engineering knowledge to architects in an interdisciplinary design team and to define how quantifying architectural design decisions have an impact during the early phases of sustainable building design.Design/methodology/approachThis work is based on a study of extensive project materials consisting of presentations, reports, simulation results and case studies. The material is made available by one of the largest European Engineering Consultancies and by a large architectural office in the field of sustainable architecture in Denmark. The project material is used for mapping communication concepts from practice.FindingsIt is demonstrated that visual communication by engineers increases the level of technical knowledge in the design decisions made by architects. This is essential in order to reach the goal of designing buildings with low environmental impact. Conversely, quantification of architectural quality improved the engineer’s acceptance of the architects’ proposals.Originality/valueThis paper produces new knowledge through the case study processes performed. The main points are presented as clearly as possible; however, it should be stressed that it is only the top of the iceberg. In all, 17 extensive case studies design processes were performed with various design teams by the 3 authors of the paper Mathilde, Birthe and Signe. The companies that provided the framework for the cases are leading in Europe within sustainability in the built environment, and in the case of Sweco also in regards to size (number of employees). Data are thus first hand and developed by the researchers and authors of this paper, with explicit consent from the industry partners involved as well as assoc. Professor Lotte B. Jensen Technical University of Denmark (DTU). This material is in the DTU servers and is in the PhD dissertation by Mathilde Landgren (successful defence was in January 2019). The observations and reflection is presented in selected significant case examples. The methods are descriped in detail, and if further information on method is required a more in depth description is found in Mathilde Landgrens PhD Dissertation. There is a lack in existing literature of the effect of visualisation in interdisciplinary design teams and though the literature (e.g. guidelines) of integrated design is extensive, there is not much published on this essential part of an integrated design process.

Tasmanian devils with contagious cancer exhibit a constricted T-cell repertoire diversity

The Tasmanian devil (Sarcophilus harrisii) is threatened by a contagious cancer, known as Devil Facial Tumour Disease (DFTD). A highly diverse T-cell receptor (TCR) repertoire is crucial for successful host defence against cancers. By investigating TCR beta chain diversity in devils of different ages, we show that the T-cell repertoire in devils constricts in their second year of life, which may explain the higher DFTD prevalence in older devils. Unexpectedly, we also observed a pronounced decline in TCR diversity and T cell clonal expansion in devils after DFTD infection. These findings overturned the previous assumption that DFTD did not directly impact host immunity.

Lwowskie studia Stanisława Kota – droga do doktoratu

Stanisław Kot, one of the creators of the history of education as a scientific discipline, studied at the University of Lvov between 1904 and 1909. His special line was classical philology, Polish philology and, for two terms, legal studies. The hitherto written relevant historical and educational literature does not address these issues in detail – Kot’s professional life in Cracow is far better known and elaborated. However, on the basis of the analysis of the Lvov archival material from the State District Archive in Lvov (primarily student catalogues and examination protocols for doctoral examinations), it is possible to reconstruct the course of studies of this well-known historian of education until the very last stage of his doctoral achievements, i.e. his successful defense of his dissertation in 1909. The scope of this study was fairly wide. The comprehensive and extensive knowledge in the history of literature, both Polish and general, history, pedagogy, philosophy and psychology that he gained in Lvov, as well as the excellent knowledge of the Polish language and classical languages, formed a firm base for Kot to pursue professional career on his own. It was the Lvov scholarly environment that shaped him as a researcher and scholar and made it possible for him to not only debut as a scholar but also to encounter and come into contact with scholars from the academic centers of Cracow. Thanks to his brilliantly-written doctoral dissertation, supervised by Wilhelm Bruchnalski and Józef Kallenbach from Lvov, and to his first publications in the periodical “Muzeum” (which he presented at a pedagogical seminar prepared by Bolesław Mańkowski), S. Kot quickly gained a reputation as a precise scholar among the university circles of the town. Also in the later period of his professional career he remained in close contact with his former university lecturers and cooperated with them, for example, on the work on the successive volumes of the publication of book series Biblioteka Narodowa (National Library).

Using Existing Research Instruments: Copyright, Permission, and Fair Use

Using Existing Research Instruments: Copyright, Permission, and Fair Use

New insights into Dutch Elm Disease: cell wall compositional, ecophysiological, vascular and nanomechanical assessments

Comprehensive assessments were made of the chemical profiles of woody cell wall components, and also leaf growth, ecophysiological, vascular and nanomechanical traits for two Dutch elm hybrids 'Groeneveld' and 'Dodoens' which possess contrasting tolerances toward Dutch elm disease. Upon infection with Ophiostoma novo-ulmi ssp. americana × novo-ulmi, medium-molecular weight macromolecules of cellulose were degraded in both hybrids. A loss of crystalline and non-crystalline cellulose regions occurred in parallel. In 'Groeneveld' plants, syringyl-rich lignin provided a far greater degree of protection from cellulose degradation, but only guaiacyl-rich lignin in 'Dodoens' plants was involved in a successful defence against the fungus. Unexpectedly, we found a very high proportion of non-significant differences between the infected and non-infected plants of 'Dodoens', including similarities in leaf growth, leaf gas exchange and leaf midrib vascular traits, as well as in the nanomechanical properties of the cell walls of tracheary elements such as modulus of elasticity, adhesion and energy dissipation. Three years after initial inoculations, except for a few traits such as leaf slenderness, relative chlorophyll content, transpiration rate and sap flow density in branches, we found no evidence of a decrease in leaf trait performances among the infected plants of 'Dodoens', despite the occasional persistence of fungal hyphae in the lumens of leaf midrib tracheary elements.

Resistant and susceptible cacao genotypes exhibit defense gene polymorphism and unique early responses to Phytophthora megakarya inoculation

Key genes potentially involved in cacao disease resistance were identified by transcriptomic analysis of important cacao cultivars. Defense gene polymorphisms were identified which could contribute to pathogen recognition capacity. Cacao suffers significant annual losses to the water mold Phytophthora spp. (Oomycetes). In West Africa, P. megakarya poses a major threat to farmer livelihood and the stability of cocoa production. As part of a long-term goal to define key disease resistance genes in cacao, here we use a transcriptomic analysis of the disease-resistant cacao clone SCA6 and the susceptible clone NA32 to characterize basal differences in gene expression, early responses to infection, and polymorphisms in defense genes. Gene expression measurements by RNA-seq along a time course revealed the strongest transcriptomic response 24h after inoculation in the resistant genotype. We observed strong regulation of several pathogenesis-related genes, pattern recognition receptors, and resistance genes, which could be critical for the ability of SCA6 to combat infection. These classes of genes also showed differences in basal expression between the two genotypes prior to infection, suggesting that prophylactic expression of defense-associated genes could contribute to SCA6's broad-spectrum disease resistance. Finally, we analyzed polymorphism in a set of defense-associated receptors, identifying coding variants between SCA6 and NA32 which could contribute to unique capacities for pathogen recognition. This work is an important step toward characterizing genetic differences underlying a successful defense response in cacao.

Jan Gösta Waldenström and rheumatology

On 2 September 1943, Jan Waldenstrom (1906–1996) successfully submitted a paper to Acta Medica Scandinavica describing two patients with a new disease. The discovery was to make him world famous.1...

The anatomy of antagonistic coregulation: Emergent coordination, path dependency, and the interplay of biomechanic parameters in Aikido

Using a video-supported cognitive ethnographic and phenomenological approach, we address the interactively generated dynamic of bouts in Aikido. This “soft” martial art enables a defender to blend with and then redirect an attacker’s aggressive energy so as to break his balance, while preserving an ethos of non-violence, mutuality, and respect. Our analysis explores the skills used to minutely adapt to the opponent, the causal-temporal structure of Aikido, notably the cumulative effect build-up and main decision points in a bout, as well as the perceptual cues from inter-body geometry, timing, and force dynamics that inform decisions. We then contrast different interaction scenarios by focusing on micro-events that shape defensive preferences. For a successful defense, technical modulations or even the preferred technique itself can be selected as the interaction unfolds (“decision-making-in-action”). For a closer look, we analyze the interplay of multiple parameters: flexibility of intention (i.e. early deciding vs. keeping options openlonger), technique (i.e. type of lever or throw), initial body symmetry, step combinations, spacing and timing relative to the attacker, degree of force, as well as possible skill differentials. We describe complex interdependencies between these parameters, which can be balanced in various ways as agents respond to the interaction dynamic.