Mitochondrial Molecular Adaptations and Life History Strategies Coevolve in Plants

Messenger RNA secondary structure prevents mutations at functionally important sites. Mutations at exposed sites would cause micro-adaptations, niche-specialization, and therefore, can be thought to promote K-strategists. Exposing, rather than protecting, conserved sites, is also potentially adaptive because they probably promote macro-adaptive changes. This presumably fits r-strategists: their population dynamics tolerate decreased survival. We found that helix-forming tendencies are greater at evolutionary conserved sites of plant mitochondrial mRNAs than at evolutionary variable sites in a majority (73%) of species–gene combinations. K-strategists preferentially protect conserved sites in short genes, r-strategists protect them most in larger genes. This adaptive scenario resembles our earlier findings in chloroplast genes. Protection levels at various codon positions also display disparity with respect to life history strategies of the plants. Conserved site protection increases overall mRNA folding stabilities for some genes, while decreases it for some others. This contrast exists between homologous genes of r- and K- strategists. Such compensating interactions between variability, mRNA size, codon position, and secondary structure factors within r- and K-strategists are most likely, molecular adaptations of plants belonging to the two extreme life history strategies. Our results suggest coevolution between molecular and ecological adaptive strategies

The pluripotent history of immunology. A review

The historiography of immunology since 1999 is reviewed, in part as a response to claims by historians such as Thomas Söderqvist the field was still immature at the time (Söderqvist & Stillwell 1999). First addressed are the difficulties, past and present, surrounding the disciplinary definition of immunology, which is followed by a commentary on the recent scholarship devoted to the concept of the immune self. The new literature on broad immunological topics is examined and assessed, and specific charges leveled against the paucity of certain types of histories, e.g. biographical and institutional histories, are evaluated. In conclusion, there are compelling indications that the history of immunology has moved past the initial tentative stages identified in the earlier reviews to become a bustling, pluripotent discipline, much like the subject of its scrutiny, and that it continues to develop in many new and exciting directions

Pluripotencjalna historia immunologii. Przegląd

[Przekład] W artykule dokonano przeglądu historiografii immunologii od 1999 roku, co w pewnym stopniu jest odpowiedzią na stanowisko takich historyków jak Thomas Söderqvist, którzy twierdzili, że to pole badawcze nie było wówczas dość rozwinięte (Söderqvist i Stillwell). Najpierw wskazano przeszłe i teraźniejsze problemy, które historiografia ma ze zdefiniowaniem immunologii, a następnie skomentowano ostatnie studia nad pojęciem immunologicznego „ja”. W dalszym toku przeglądu przeanalizowano i oceniono nowe publikacje poświęcone zróżnicowanym zagadnieniom immunologii oraz niektóre charakterystyczne oskarżenia formułowane wobec niedostatku pewnych dziedzin historii, na przykład historii biograficznych i historii instytucji. W podsumowaniu przedstawiono konkurujące ze sobą kierunki, w których rozwinęła się historia immunologii, wychodząc poza wstępne, tymczasowe stadia uchwycone w poprzednim przeglądzie, i stając się wielogłosową, pluripotencjalną dyscypliną, podobną do przedmiotu jej badań. Pokazano też, że historia immunologii nadal rozwija się na wiele nowych i ekscytujących sposobów

Chchd10, A Novel Bi-Organellar Regulator Of Cellular Metabolism: Implications In Neurodegeneration

CHCHD10 (Coiled-coil Helix Coiled-coil Helix Domain containing protein 10) and MNRR1 (Mitochondrial Nuclear Retrograde Regulator 1, also known as CHCHD2), have been shown by us to be stress regulators of mitochondrial function that act both in the mitochondria and in the nucleus. Both are members of the twin CX9C family, but CHCHD10 in particular, has been found in mutant form to be linked to a myriad of neurodegenerative conditions. In mitochondria, both activate cytochrome c oxidase (COX) whereas in the nucleus, both act as transcription regulators of a subset of genes that contain a 13-bp sequence termed as the oxygen responsive element (ORE). We previously modeled events at the ORE to consist of a complex of RBPJk with either the transcriptional repressor CXXC5 or the transcriptional activator MNRR1. We show that CHCHD10 co-purifies with COX and up-regulates its activity by serving as a scaffolding protein required for MNRR1 phosphorylation, mediated by ARG (ABL2 kinase). Surprisingly, in the nucleus CHCHD10 protein down-regulates the expression of ORE-harboring genes by interacting with and augmenting the activity of CXXC5. The CHCHD10 gene is maximally transcribed in cultured cells at 8% oxygen, unlike MNRR1, which is maximally expressed at 4%, suggesting a fine-tuned oxygen-sensing system that adapts to the varying oxygen concentrations in the human body. We also show that cells predominantly harboring two CHCHD10 disease mutants (G66V and P80L) are defective for cellular oxidative phosphorylation, have lower membrane potential and higher reactive oxygen species (ROS) levels as compared to WT-CHCHD10. The mutant proteins are also defective in the nucleus as they fail to interact with CXXC5 and repress transcription at the ORE. Taken together, these effects point to a putative cellular mitochondrial defect as well dysregulation of transcription of ORE-harboring gene leading to the neurodegenerative phenotype observed in patients. We discuss these findings to generate a generalized model for cellular responses to moderate levels of hypoxia and a possible mechanism for the observed phenotype in patients with mutations in this gene

Covariance Realization Problem for Spin Systems

Let (Ω, Α) be a measurable space, F be a family of measurable functions f from Ω to R, and c: F→R be a given function. A generalized moment problem consists of finding all probabilities P on (Ω, Α) such that ∫ f dP = c(f) = cf for all f є F, and in providing conditions on ( c ) f є F for the existence of at least one such probability. Generalized moment problems of this kind have been widely studied, mainly in the theoretical engineering community, for continuous random variables. In this thesis, we consider the special case of the covariance realization problem for spin systems and discuss the necessary and sufficient conditions for the realizability of a correlation matrix of order n ≥ 2. Let Ωn = { -1, 1}ⁿ be the space of length n sequences which are denoted by σ = (σ1, σ 2, …, σn), where σi є { -1, 1 }. Define the spin random variables ξi : Ω →{ -1, 1} for 1 ≤ i ≤ n as ξi (σ ) = σ i . For a probability P on Ωn , we denote by EP the expectation with respect to P . Given a symmetric matrix C = (( c ij)), we ask the following question in this thesis: under what condition does there exist a probability P such that EP (ξi) = 0 and c ij = EP (ξi ξj) for 1 ≤ i ≤ j ≤ n ? In this case, we say that C is a spin correlation matrix. The necessary and sufficient conditions for a symmetric matrix of order n ≤ 4 to be a spin correlation matrix are already known. In this thesis, we obtain a general set of inequalities that are necessary and sufficient for any n . We also give a minimal set of necessary and sufficient conditions for n=5,6. Finally, we discuss methods to explicitly find the measure that realizes the given spin correlations (if they are feasible). We give a deterministic algorithm as well as a stochastic version of the same algorithm to find the measure explicitly. The efficiency of different algorithms is compared and some examples are worked out to illustrate the point

Assessment of Self-Concept among Children with Special Needs

The self is one’s inner world. It results from evolutional interaction with others, becoming the consistent personal perception of “I” and “Me”. The self-concept really is the individual’s anticipation of his general acceptance or rejection in a given situation; as the self concept is formulated, it tends to shape to new experience and to an established pattern. A handicapped child may be defined as one who suffers from any continuing disability of body, intellect or personality which is likely to interfere with his normal growth and development or capacity to learn. Self-concept means the totality of attitudes, judgment and values of an individual relating to his behavior, abilities and qualities. This self-concept is the evaluation of the self and develops in relation to an individual’s creative behavior. During early life the child’s self evaluation is heavily dependent on the ways in which others accept him, specially his parents and other family members. For the purpose of the study a total of 96 children were selected. 32 each from the visually challenged, hearing impaired and Orthopaedically challenged. Within each group of 32 children, 8 boys and 8 girls (16) from 11-12 years age group and 8 boys and 8 girls (16) from 13-14 years age group were selected. Each child’s self-concept was assessed by using the Tennesse self-concept scale modified and cross validated by Vasundhara Devi (1985). This scale consists of 80 items distributed over eight dimensions to measure the overall level of self-concept. Each dimension consists of 10 items. In visually challenged children boys of 11-12 years recorded highest score for “family-self” and “behaviour and self-satisfaction” (mean score = 26.8 each). In girls of 11-12 years the top score was for “physical-self” (mean score=34.6). Hearing impaired boys of both age-groups recorded highest score “physical-self” (28.1). In contrast in hearing impaired girls “social-self” registered the best mean score (27 and 26.9) in the two age-groups. Orthopeadically challenged boys of both age-groups scored highest for ‘social-self’ (24.9). Compared to boys in Orthopaedically challenged girls “Physical-self” and “social-self” shared the top spot in scores (mean score=26.2 each) in 11-12 years group. In 13-14 age-group of girls “Physical- self” scored highest (mean score=24) .Irrespective of type of disability gender or age-groups, compared to other dimensions of self-concept moral-self and ethical-self recorded the least scores