Search Results (9)

Suicidality is among the most controversial concepts in multi-disciplinary studies worldwide, regardless of the form and approach. The etiopathological variability in suicidal ideation correlates with the heterogeneity of the clinical and behavioural patterns of self-harm attempts, which significantly impact the prognosis and quality of life of patients. The main objective of the present study was to identify and outline the spectrum of factors predisposing to suicide, with the whole suite of consequences and manifestations in ideation and behaviour. In this regard, the research literature of the last decade contains numerous articles dealing with the theoretical premises pertaining to both the statistical and the profoundly psychological and philosophical dimensions of suicide. The micro-environment favouring the clinical evolution of self-harm/self-destructive thoughts and attempts to the terminal, final act integrates individual medical-biological and psychological factors into the overall social reality. Knowledge of the whole etiopathogenic amalgam with clinical-evolutionary implications allows for the development of methods and tools for the early assessment and prevention of suicidal risk. At the same time, the present study aims to qualitatively focus on the subjective motivation declared by patients regarding the internal, individual catalyst of suicidal ideation and attempts on a predominantly psycho-social coordination. Full article

Severe acne has high psychological impacts recorded worldwide, from depression to suicide. To control acne infection, bacteriophage could be used in synergy or combination with antibiotics/antimicrobials. Bacteriophages are specific to their hosts without interfering with the normal skin microbes and have the ability to lyse bacterial cells. In this current study, the bacteriophage PAP 1-1 was isolated, characterized, and tested against the pathogenic acne-causing bacterium Cutibacterium acnes. Examination under transmission electron microscopy (TEM) revealed that the newly isolated phage has a morphology typical of siphoviruses. Phylogenetic analysis, utilizing the maximum likelihood (ML) algorithm based on complete genome sequences, revealed that PAP 1-1 clustered together with bacteriophages active to Propionibacterium acnes (now known as C. acnes), forming a distinct evolutionary lineage. The genomic analysis further identified the presence of an endolysin gene in PAP 1-1, suggesting its potential to regulate the growth of C. acnes. Subsequent experiments conducted in RCM broth confirmed the ability of PAP 1-1 to effectively control the proliferation of C. acnes. In combination with bacteriocin from Lactococcus lactis CJNU 3001 and nisin, PAP 1-1 greatly decreased the viable cell counts of C. acnes in the broth. Full article

The problem of evil seems to have been the patent of theism for a long time. However, some philosophers notice that this is not necessarily the case and raise arguments from evil against atheism. In this paper, I follow this insight and raise the evidential argument from evil against naturalism. I argue that some human behaviors that cause evil and suffering contradict the principles of evolution and should not exist in a naturalistic world. Nevertheless, they do exist, and they accordingly disconfirm naturalism. To attain this conclusion, I first establish that psychological mechanisms as evolutionary causes are the ultimate causes of human behaviors if naturalism is true. Then, I argue that cases of rape with murder and suicide have contravened their relevant psychological mechanisms’ adaptive functions and should not exist. Therefore, cases of these behaviors make it reasonable to believe that naturalism is not true. Both naturalists and theists now have to raise plausible explanations for various evils in the world. It is possible for theism to outcompete naturalism with respect to evil as a result. Full article

The mammalian cytochrome P450 monooxygenase CYP4B1 can bioactivate a wide range of xenobiotics, such as its defining/hallmark substrate 4-ipomeanol leading to tissue-specific toxicities. Similar to other members of the CYP4 family, CYP4B1 has the ability to hydroxylate fatty acids and fatty alcohols. Structural insights into the enigmatic role of CYP4B1 with functions in both, xenobiotic and endobiotic metabolism, as well as its unusual heme-binding characteristics are now possible by the recently solved crystal structures of native rabbit CYP4B1 and the p.E310A variant. Importantly, CYP4B1 does not play a major role in hepatic P450-catalyzed phase I drug metabolism due to its predominant extra-hepatic expression, mainly in the lung. In addition, no catalytic activity of human CYP4B1 has been observed owing to a unique substitution of an evolutionary strongly conserved proline 427 to serine. Nevertheless, association of CYP4B1 expression patterns with various cancers and potential roles in cancer development have been reported for the human enzyme. This review will summarize the current status of CYP4B1 research with a spotlight on its roles in the metabolism of endogenous and exogenous compounds, structural properties, and cancer association, as well as its potential application in suicide gene approaches for targeted cancer therapy. Full article

Systems with multiple time scales, often referred to as `slow–fast systems’, have been a focus of research for about three decades. Such systems show a variety of interesting, sometimes counter-intuitive dynamical behaviors and are believed to, in many cases, provide a more realistic description of ecological dynamics. In particular, the presence of slow–fast time scales is known to be one of the main mechanisms resulting in long transients—dynamical behavior that mimics a system’s asymptotic regime but only lasts for a finite (albeit very long) time. A prey–predator system where the prey growth rate is much larger than that of the predator is a paradigmatic example of slow–fast systems. In this paper, we provide detailed investigation of a more advanced variant of prey–predator system that has been overlooked in previous studies, that is, where the predator response is ratio-dependent and the predator mortality is nonlinear. We perform a comprehensive analytical study of this system to reveal a sequence of bifurcations that are responsible for the change in the system dynamics from a simple steady state and/or a limit cycle to canards and relaxation oscillations. We then consider how those changes in the system dynamics affect the properties of long transient dynamics. We conclude with a discussion of the ecological implications of our findings, in particular to argue that the changes in the system dynamics in response to an increase of the time scale ratio are counter-intuitive or even paradoxical. Full article

Toxin-antitoxin (TA) systems are small genetic modules that encode a toxin (that targets an essential cellular process) and an antitoxin that neutralises or suppresses the deleterious effect of the toxin. Based on the molecular nature of the toxin and antitoxin components, TA systems are categorised into different types. Type III TA systems, the focus of this review, are composed of a toxic endoribonuclease neutralised by a non-coding RNA antitoxin in a pseudoknotted configuration. Bioinformatic analysis shows that the Type III systems can be classified into subtypes. These TA systems were originally discovered through a phage resistance phenotype arising due to a process akin to an altruistic suicide; the phenomenon of abortive infection. Some Type III TA systems are bifunctional and can stabilise plasmids during vegetative growth and sporulation. Features particular to Type III systems are explored here, emphasising some of the characteristics of the RNA antitoxin and how these may affect the co-evolutionary relationship between toxins and cognate antitoxins in their quaternary structures. Finally, an updated analysis of the distribution and diversity of these systems are presented and discussed. Full article

Mechanisms of self-destruction are difficult to reconcile with evolution’s first rule of thumb: survive and reproduce. However, evolutionary success ultimately depends on inclusive fitness. The altruistic suicide hypothesis posits that the presence of low reproductive potential and burdensomeness toward kin can increase the inclusive fitness payoff of self-removal. The bargaining hypothesis assumes that suicide attempts could function as an honest signal of need. The payoff may be positive if the suicidal person has a low reproductive potential. The parasite manipulation hypothesis is founded on the rodent—Toxoplasma gondii host-parasite model, in which the parasite induces a “suicidal” feline attraction that allows the parasite to complete its life cycle. Interestingly, latent infection by T. gondii has been shown to cause behavioral alterations in humans, including increased suicide attempts. Finally, we discuss how suicide risk factors can be understood as nonadaptive byproducts of evolved mechanisms that malfunction. Although most of the mechanisms proposed in this article are largely speculative, the hypotheses that we raise accept self-destructive behavior within the framework of evolutionary theory. Full article

We analyze a model in which individuals have hereditary reproductive types. The reproductive value of an individual is determined by her reproductive type and the amount of resources she can access. We introduce the possibility of suicide and assume it is also a genetic trait that interacts with the reproductive type of an individual. The main result of the paper is that populations where suicide is possible grow faster than other populations. Full article