Non-local image deconvolution by Cauchy sequence

We present the deconvolution between two smooth function vectors as a Cauchy sequence of weight functions. From this we develop a Taylor series expansion of the convolution problem that leads to a non-local approximation for the deconvolution in terms of continuous function spaces. Optimisation of this form against a given measure of error produces a theoretically more exact algorithm. The discretization of this formulation provides a deconvolution iteration that deconvolves images quicker than the Richardson-Lucy algorithm.Comment: 12 pages, 3 figure

Mode of reproduction is detected by Parth1 and Sex1 SCAR markers in a wide range of facultative

Abstract Gametophytic apomixis in Kentucky bluegrass (Poa pratensis L.) involves the parthenogenetic development of unreduced eggs from aposporic embryo sacs. Marker-assisted selection for the mode of reproduction in P. pratensis would avoid costly and time-consuming phenotypic progeny tests. We developed and tested two SCAR primer pairs that are associated with the mode of reproduction in P. pratensis. The SCAR primers identified the apomictic and sexual genotypes among progenies of sexual x apomictic crosses with very low bias. Furthermore, when tested on a wide range of Italian and exotic P. pratensis germplasm, they were able to unequivocally distinguish sexual from apomictic genotypes. This system should, therefore, allow new selection models to be set up in this species

Structure, target-specificity and expression of PN_LNC_N13, a long non-coding RNA differentially expressed in apomictic and sexual Paspalum notatum

Key message: ncRNA PN_LNC_N13 shows contrasting expression in reproductive organs of sexual and apomictic Paspalum notatum genotypes. Abstract: Apomictic plants set genetically maternal seeds whose embryos derive by parthenogenesis from unreduced egg cells, giving rise to clonal offspring. Several Paspalum notatum apomixis related genes were identified in prior work by comparative transcriptome analyses. Here, one of these candidates (namely N13) was characterized. N13 belongs to a Paspalum gene family including 30–60 members, of which at least eight are expressed at moderate levels in florets. The sequences of these genes show no functional ORFs, but include segments of different protein coding genes. Particularly, N13 shows partial identity to maize gene BT068773 (RESPONSE REGULATOR 6). Secondary structure predictions as well as mature miRNA and target cleavage detection suggested that N13 is not a miRNA precursor. Moreover, N13 family members produce abundant 24-nucleotide small RNAs along extensive parts of their sequences. Surveys in the GREENC and CANTATA databases indicated similarity with plant long non-coding RNAs (lncRNAs) involved in splicing regulation; consequently, N13 was renamed as PN_LNC_N13. The Paspalum BT068773 predicted ortholog (N13TAR) originates floral transcript variants shorter than the canonical maize isoform and with possible structural differences between the apomictic and sexual types. PN_LNC_N13 is expressed only in apomictic plants and displays quantitative representation variation across reproductive developmental stages. However, PN_LNC_N13-like homologs and/or its derived sRNAs showed overall a higher representation in ovules of sexual plants at late premeiosis. Our results suggest the existence of a whole family of N13-like lncRNAs possibly involved in splicing regulation, with some members characterized by differential activity across reproductive types.Fil: Ochogavía, Ana Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Galla, Giulio. Università di Padova; ItaliaFil: Seijo, José Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: González, Ana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Bellucci, Michele. Consiglio Nazionale delle Ricerche; ItaliaFil: Pupilli, Fulvio. Consiglio Nazionale delle Ricerche; ItaliaFil: Barcaccia, Gianni. Università di Padova; ItaliaFil: Albertini, Emidio. Università di Perugia; ItaliaFil: Pessino, Silvina Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentin

Structure, target-specificity and expression of PN_LNC_N13, a long non-coding RNA differentially expressed in apomictic and sexual Paspalum notatum.

The ncRNA PN_LNC_N13 shows contrasting expression in reproductive organs of sexual and apomictic Paspalum notatum genotypes. Apomictic plants set genetically maternal seeds whose embryos derive by parthenogenesis from unreduced egg cells, giving rise to clonal offspring. Several Paspalum notatum apomixis related genes were identified in prior work by comparative transcriptome analyses. Here, one of these candidates (namely N13) was characterized. N13 belongs to a Paspalum gene family including 30-60 members, of which at least eight are expressed at moderate levels in florets. The sequences of these genes show no functional ORFs, but include segments of different protein coding genes. Particularly, N13 shows partial identity to maize gene BT068773 (RESPONSE REGULATOR 6). Secondary structure predictions as well as mature miRNA and target cleavage detection suggested that N13 is not a miRNA precursor. Moreover, N13 family members produce abundant 24-nucleotide small RNAs along extensive parts of their sequences. Surveys in the GREENC and CANTATA databases indicated similarity with plant long non-coding RNAs (lncRNAs) involved in splicing regulation; consequently, N13 was renamed as PN_LNC_N13. The Paspalum BT068773 predicted ortholog (N13TAR) originates floral transcript variants shorter than the canonical maize isoform and with possible structural differences between the apomictic and sexual types. PN_LNC_N13 is expressed only in apomictic plants and displays quantitative representation variation across reproductive developmental stages. However, PN_LNC_N13-like homologs and/or its derived sRNAs showed overall a higher representation in ovules of sexual plants at late premeiosis. Our results suggest the existence of a whole family of N13-like lncRNAs possibly involved in splicing regulation, with some members characterized by differential activity across reproductive types

A review on apomeiosis in Poa pratensis and Medicago sativa mutants.

In contrast to sexual reproduction, apomixis bypasses meiosis and egg cell fertilization. Gametophytic apomixis occurs with the parthenogenetic development of unreduced egg cells from apomeiotic embryo sacs originating from a nucellar somatic cell (apospory) or a megaspore mother cell with no, or modified, meiosis (diplospory). Apomeiosis, along with parthenogenesis, excludes segregation and recombination during meiosis and fertilization. Thus, understanding the genetic control and the molecular mechanisms underlying apomeiosis is critical for the comprehension of apomixis as a whole. In this paper we review the available data on apospory in the facultative apomictic species Kentucky bluegrass (Poa pratensis L.) and on diplospory in reproductive mutants of the sexual species alfalfa (Medicago sativa L.). Our recent acquisitions on candidate genes for apomeiosis are reported and strategies for elucidating the inheritance of this trait by means of genomics and expression studies are presented and discussed. In particular, experimental data focus on PpSERK and MsMob1 genes. We document that PpSERK transcripts are specifically expressed in the megaspore mother cells of sexual genotypes and in the aposporic initials of sexual genotypes, suggesting that PpSERK plays a role in early stages of embryo sac development. Moreover, the altered expression of MsMob1 in ovules of a reproductive mutant producing diplosporic eggs is reported, and the implication of MsMob1 proteins in programmed cell death of meiotic megaspores is also considered

Apomixis in plant reproduction: a novel perspective on an old dilemma.

Seed is one of the key factors of crop productivity. Therefore, a comprehension of the mechanisms underlying seed formation in cultivated plants is crucial for the quantitative and qualitative progress of agricultural production. In angiosperms, two pathways of reproduction through seed exist: sexual or amphimictic, and asexual or apomictic; the former is largely exploited by seed companies for breeding new varieties, whereas the latter is receiving continuously increasing attention from both scientific and industrial sectors in basic research projects. If apomixis is engineered into sexual crops in a controlled manner, its impact on agriculture will be broad and profound. In fact, apomixis will allow clonal seed production and thus enable efficient and consistent yields of high-quality seeds, fruits, and vegetables at lower costs. The development of apomixis technology is expected to have a revolutionary impact on agricultural and food production by reducing cost and breeding time, and avoiding the complications that are typical of sexual reproduction (e.g., incompatibility barriers) and vegetative propagation (e.g., viral transfer). However, the development of apomixis technology in agriculture requires a deeper knowledge of the mechanisms that regulate reproductive development in plants. This knowledge is a necessary prerequisite to understanding the genetic control of the apomictic process and its deviations from the sexual process. Our molecular understanding of apomixis will be greatly advanced when genes that are specifically or differentially expressed during embryo and embryo sac formation are discovered. In our review, we report the main findings on this subject by examining two approaches: i) analysis of the apomictic process in natural apomictic species to search for genes controlling apomixis and ii) analysis of gene mutations resembling apomixis or its components in species that normally reproduce sexually. In fact, our opinion is that a novel perspective on this old dilemma pertaining to the molecular control of apomixis can emerge from a cross-check among candidate genes in natural apomicts and a high-throughput analysis of sexual mutants

Beyond Hydrogen Loading

While experimental and technological attention is focused on the operational methods for hydrogen loading in metals and on the observed anomalies with respect to well-established rules, we aim to remark that these methods and these consequences can be seen as a part of a more general problem. In fact, most of the experiments and deductions of material sciences are based on the assumption that space-time is flat and isotropic (Minkowskian). After discarding this assumption, a theory of Deformed Space Time (DST) was developed in the last decades. Following this theory, experimental results were obtained which are not predicted by the Standard Model. The DST-theory concerns the fundamental interactions and in particular the nuclear ones, that can play the main role in the observed anomalies. In order to consider a nuclear reaction as a DST-reaction, four main phenomenological features were deduced: occurrence of an energy threshold; change of atomic weight; absence of gamma radiation; anisotropic emission of nuclear particles in intense beams having a very short life span. From the experimental point of view, rather than looking for fortuitous events that produce the conditions for DST-reactions, more systematic research can be undertaken by following the above reported four general rules. In particular, the occurrence of a thresholds can correspond to a latency time, necessary to reach the energy density necessary to deform space-time. The absence of gamma radiation cannot be considered as a sign that nuclear reactions are not present; in fact, in absence of detected gamma radiation elements were found which were not present before the reaction. The nuclear emissions, which are anisotropic and impulsive, can be difficult to detect with the traditional methods, thus inducing incertitude on the occurring reactions. Finally, a rapid variation of energy density is an experimental common factor of DST-reactions. Thus, the DST-theory can be the leading theory in the design of the experiment and in the interpretation of its experimental results

Non-local image deconvolution by Cauchy sequence

We present the deconvolution between two smooth function vectors as a Cauchy sequence of weight functions. From this we develop a Taylor series expansion of the convolution problem that leads to a non-local approximation for the deconvolution in terms of continuous function spaces. Optimisation of this form against a given measure of error produces a theoretically more exact algorithm. The discretization of this formulation provides a deconvolution iteration that deconvolves images quicker than the Richardson-Lucy algorithm