Parallel Loss Research Articles

Intensity Specific Repetitive Mild Traumatic Brain Injury Evokes an Exacerbated Burden of Neocortical Axonal Injury.

Mild traumatic brain injury (mTBI) has been linked to enduring neurological damage following repetitive injury. Previously, we reported that intensity-specific, repetitive mTBI exacerbated microvascular and axonal damage in brainstem. For a more rigorous and global assessment, we assessed the burden of neocortical diffuse axonal injury (DAI) evoked by repetitive mTBI. Mice were subjected to mild central fluid percussion injuries at 1.4 and 1.6 atm with or without repetitive insult at a 3-hour interval and killed at 24 hours postinjury. Neocortical DAI within layer V was quantitatively assessed by double-labeling p-c-Jun and NeuN to identify both the axotomized and total neuronal population. Both confocal and electron microscopic findings revealed no apparent evidence of neuronal death. Repetitive mTBI of 1.6 atm group, but not of 1.4 atm group, demonstrated a significantly higher proportion of axotomized neurons. These results demonstrate that different intensities of mTBI induced different burdens of DAI after repetitive insult. Interestingly, the parallel loss of the righting reflex reflected differences in injury intensity, yet the duration of this reflex was not elongated by the repetitive insult. These data highlight some of the complex issues surrounding repetitive mTBI and its associated morbidity, mandating the need for continued exploration.

Photosynthesis and calcification of charophytes

Charophytes of the genus Chara can form a bottom-dwelling calcified vegetation of high density in nutrient-poor hardwater lakes and ponds, whereas they are rare compared to tall canopy-forming vascular plants (elodeids) in nutrient-rich waters. Based on the preferred habitat and appearance, we hypothesized that Chara species may use bicarbonate efficiently for photosynthesis accompanied by calcification. We measured photosynthesis and calcification in incubation experiments of 3–18 h duration with seven species of Chara by quantifying changes in dissolved inorganic carbon (DIC), oxygen, alkalinity and calcium. All Chara-species used bicarbonate efficiently according to: 1) an unaltered photosynthetic rate between pH 7.5 and 8.5 and a modest decline at pH 9.5, and 2) their ability to drive pH above 10 and deplete CO2 below 0.1 μM. Calcification measured by the parallel loss of bicarbonate and dissolved calcium to precipitated calcium carbonate increased markedly with rising pH, resulting in additional consumption of DIC and a falling molar quotient of oxygen release to DIC consumption from 1.61 at pH 7.5 to 0.68 at pH 9.5. The stoichiometry of alkalinity and calcium loss relative to oxygen production at pH 9.5 was in accordance with simultaneous calcification and photosynthetic assimilation, which buffers pH rise. Our findings support that Chara species are efficient bicarbonate users and calcifying organisms. Through calcification, Chara species maintain photosynthesis at high pH and can form dense stands in oligotrophic hardwater lakes and ponds.

Comparative genomics of the nonlegume Parasponia reveals insights into evolution of nitrogen-fixing rhizobium symbioses

Nodules harboring nitrogen-fixing rhizobia are a well-known trait of legumes, but nodules also occur in other plant lineages, with rhizobia or the actinomycete Frankia as microsymbiont. It is generally assumed that nodulation evolved independently multiple times. However, molecular-genetic support for this hypothesis is lacking, as the genetic changes underlying nodule evolution remain elusive. We conducted genetic and comparative genomics studies by using Parasponia species (Cannabaceae), the only nonlegumes that can establish nitrogen-fixing nodules with rhizobium. Intergeneric crosses between Parasponia andersonii and its nonnodulating relative Trema tomentosa demonstrated that nodule organogenesis, but not intracellular infection, is a dominant genetic trait. Comparative transcriptomics of P. andersonii and the legume Medicago truncatula revealed utilization of at least 290 orthologous symbiosis genes in nodules. Among these are key genes that, in legumes, are essential for nodulation, including NODULE INCEPTION (NIN) and RHIZOBIUM-DIRECTED POLAR GROWTH (RPG). Comparative analysis of genomes from three Parasponia species and related nonnodulating plant species show evidence of parallel loss in nonnodulating species of putative orthologs of NIN, RPG, and NOD FACTOR PERCEPTION Parallel loss of these symbiosis genes indicates that these nonnodulating lineages lost the potential to nodulate. Taken together, our results challenge the view that nodulation evolved in parallel and raises the possibility that nodulation originated ∼100 Mya in a common ancestor of all nodulating plant species, but was subsequently lost in many descendant lineages. This will have profound implications for translational approaches aimed at engineering nitrogen-fixing nodules in crop plants.

Dependence of magnetic and microwave loss on evolving microstructure in yttrium iron garnet

The parallel magnetic and microwave loss dependence on microstructural evolutions in several polycrystalline yttrium iron garnet samples were studied in detail, focusing on the attendant occurrence of their relationships. In this study, polycrystalline YIG samples were synthesized by employing the mechanical alloying technique and sintering toroidal compacts at temperatures from 600 to 1400 °C. The samples were characterized for their evolution in crystalline phases, structure, microstructure, magnetic hysteresis parameters, microwave losses and electrical resistivity. The results showed an increasing tendency of the saturation magnetization with grain size, which is attributed to crystallinity increase in the grains. The M–H hysteresis loop results showed a transition from disordered-to-ordered magnetism which belongs to different magnetically dominant stages of formation. The starting appearance of room temperature ferromagnetic order suggested by the sigmoid-shaped loops seems to be dependent on crystallinity, phase purity and a sufficient number of large enough magnetic domain-containing grains having been formed in the microstructure. An increasing trend of transmission loss with grain size may be attributed to increment of loss contribution from hysteresis and domain wall resonance of the samples. The changes in crystallinity and microstructure, and the associated processes of microwave resonance and relaxation due to domain wall movements and damping of spin rotation contributes to the variations in transmission loss and ferromagnetic linewidth of the samples. The increased electrical resistivity while the microstructure was evolving is believed to strongly indicates improved phase purity and compositional stoichiometry.

Pisiform malalignment associated with distal radius fractures.

The association of scaphoid or other carpal bone fractures with distal radius fractures is frequently reported, whereas few studies have described pisiform malalignment associated with distal radius fractures. The purpose of this study was to investigate the frequency and characteristics of pisiform malalignment associated with distal radius fractures. We performed a retrospective study by reviewing the data of 152 consecutive patients with a mean age of 63 years who were treated surgically for distal radius fractures during a five-year period. We evaluated the pisotriquetral joint via preoperative sagittal computed tomography (CT) and assessed pisiform malalignment. Pisiform malalignment was defined as follows: (1) wide type, joint space ≥4.0mm; (2) non-parallel type, loss of parallelism of the joint surface of ≥20°; or (3) overriding type, proximal or distal overriding of the pisotriquetral joint ≥2.0mm. We investigated the relationship between pisiform malalignment and the patterns of distal radius fractures. Pisiform malalignment was assessed using postoperative CT to determine whether it had been reduced. Pisiform malalignment was observed in 48 cases involving 44 patients with a mean age of 58 (17-81) years. The patients included 16, 17, and 15 cases of the wide type, non-parallel type, and overriding type, respectively. Distal radius fractures with dorsal displacement exhibited pisiform malalignment significantly more frequently than those with volar displacement. No significant difference was noted between intra- and extra-articular fractures or between patients with and without distal ulnar fractures. Among the 22 pisiform malalignment cases assessed via postoperative CT, 15 cases were reduced, and 7 cases remained malaligned. The non-parallel type exhibited the lowest reduction rate among the 3 types. Among distal radius fractures, 29% were complicated by pisiform malalignment. Distal radius fractures with dorsal displacement exhibited a significantly increased frequency of pisiform malalignment compared to those with volar displacement.

Phylogenomic inference in extremis: A case study with mycoheterotroph plastomes.

Phylogenomic studies employing large numbers of genes, including those based on plastid genomes (plastomes), are becoming common. Nonphotosynthetic plants such as mycoheterotrophs (which rely on root-associated fungi for essential nutrients, including carbon) tend to have highly elevated rates of plastome evolution, substantial genome reduction, or both. Mycoheterotroph plastomes therefore provide excellent test cases for investigating how extreme conditions impact phylogenomic inference. We used parsimony and likelihood analysis of protein-coding gene sets from published and newly completed plastomes to infer the phylogenetic placement of taxa from the 10 angiosperm families in which mycoheterotrophy evolved. Despite multiple very long branches that reflect elevated substitution rates, and frequently patchy gene recovery due to genome reduction, inferred phylogenetic placements of most mycoheterotrophic lineages in DNA-based likelihood analyses are both well supported and congruent with other studies. Amino-acid-based likelihood placements are broadly consistent with DNA-based inferences, but extremely rate-elevated taxa can have unexpected placements-albeit with weak support. In contrast, parsimony analysis is strongly misled by long-branch attraction among many distantly related mycoheterotrophic monocots. Mycoheterotrophic plastomes provide challenging cases for phylogenomic inference, as substitutional rates can be elevated and genome reduction can lead to sparse gene recovery. Nonetheless, diverse likelihood frameworks provide generally well-supported and mutually concordant phylogenetic placements of mycoheterotrophs, consistent with recent phylogenetic studies and angiosperm-wide classifications. Previous predictions of parallel photosynthesis loss within families are supported for Burmanniaceae, Ericaceae, Gentianaceae, and Orchidaceae. Burmanniaceae and Thismiaceae should not be combined as a single family in Dioscoreales.

Evolution of the Phosphatidylcholine Biosynthesis Pathways in Green Algae: Combinatorial Diversity of Methyltransferases.

Phosphatidylcholine (PC) is one of the most common phospholipids in eukaryotes, although some green algae such as Chlamydomonas reinhardtii are known to lack PC. Recently, we detected PC in four species in the genus Chlamydomonas: C. applanata NIES-2202, C. asymmetrica NIES-2207, C. debaryana NIES-2212, and C. sphaeroides NIES-2242. To reveal the PC biosynthesis pathways in green algae and the evolutionary scenario involved in their diversity, we analyzed the PC biosynthesis genes in these four algae using draft genome sequences. Homology searches suggested that PC in these species is synthesized by phosphoethanolamine-N-methyltransferase (PEAMT) and/or phosphatidylethanolamine-N-methyltransferase (PEMT), both of which are absent in C. reinhardtii. Recombinant PEAMTs from these algae showed methyltransferase activity for phosphoethanolamine but not for monomethyl phosphoethanolamine in vitro, in contrast to land plant PEAMT, which catalyzes the three methylations from phosphoethanolamine to phosphocholine. This suggested an involvement of other methyltransferases in PC biosynthesis. Here, we characterized the putative phospholipid-N-methyltransferase (PLMT) genes of these species by genetic and phylogenetic analysis. Complementation assays using a PC biosynthesis-deficient yeast suggested that the PLMTs of these algae can synthesize PC from phosphatidylethanolamine. These results indicated that the PC biosynthesis pathways in green algae differ from those of land plants, although the enzymes involved are homologous. Phylogenetic analysis suggested that the PEAMTs and PLMTs in these algae were inherited from the common ancestor of green algae. The absence of PC biosynthesis in many Chlamydomonas species is likely a result of parallel losses of PEAMT and PLMT in this genus.

Parallel loss of introns in the ABCB1 gene in angiosperms

BackgroundThe presence of non-coding introns is a characteristic feature of most eukaryotic genes. While the size of the introns, number of introns per gene and the number of intron-containing genes can vary greatly between sequenced eukaryotic genomes, the structure of a gene with reference to intron presence and positions is typically conserved in closely related species. Unexpectedly, the ABCB1 (ATP-Binding Cassette Subfamily B Member 1) gene which encodes a P-glycoprotein and underlies dwarfing traits in maize (br2), sorghum (dw3) and pearl millet (d2) displayed considerable variation in intron composition.ResultsAn analysis of the ABCB1 gene structure in 80 angiosperms revealed that the number of introns ranged from one to nine. All introns in ABCB1 underwent either a one-time loss (single loss in one lineage/species) or multiple independent losses (parallel loss in two or more lineages/species) with the majority of losses occurring within the grass family. In contrast, the structure of the closest homolog to ABCB1, ABCB19, remained constant in the majority of angiosperms analyzed. Using known phylogenetic relationships within the grasses, we determined the ancestral branch-points where the losses occurred. Intron 7, the longest intron, was lost in only a single species, Mimulus guttatus, following duplication of ABCB1. Semiquantitative PCR showed that the M. guttatus ABCB1 gene copy without intron 7 had significantly lower transcript levels than the gene copy with intron 7. We further demonstrated that intron 7 carried two motifs that were highly conserved across the monocot-dicot divide.ConclusionsThe ABCB1 gene structure is highly dynamic, while the structure of ABCB19 remained largely conserved through evolution. Precise removal of introns, preferential removal of smaller introns and presence of at least 2 bp of microhomology flanking most introns indicated that intron loss may have predominantly occurred through non-homologous end-joining (NHEJ) repair of double strand breaks. Lack of microhomology in the exon upstream of lost phase I introns was likely due to release of the selective constraint on the penultimate base (3rd base in codon) of the terminal codon by the splicing machinery. In addition to size, the presence of regulatory motifs will make introns recalcitrant to loss.

Translational opportunities for broad-spectrum natural phytochemicals and targeted agent combinations in breast cancer.

Breast cancer (BC) prevention and therapy in the context of life-style risk factors and biological drivers is a major focus of developmental therapeutics in oncology. Obesity, alcohol, chronic estrogen signaling and smoking have distinct BC precipitating and facilitating effects that may act alone or in combination. A spectrum of signaling events including enhanced oxidative stress and changes in estrogen-receptor (ER)-dependent and -independent signaling drive the progression of BC. Breast tumors modulate ERα/ERβ ratio, upregulate proliferative pathways driven by ERα and HER2 with a parallel loss and/or downregulation of tumor suppressors such as TP53 and PTEN which together impact the efficacy of therapeutic strategies and frequently lead to emergence of drug resistance. Natural phytochemicals modulate oxidative stress, leptin, integrin, HER2, MAPK, ERK, Wnt/β-catenin and NFκB signaling along with regulating ERα and ERβ, thereby presenting unique opportunities for both primary and combinatorial interventions in BC. In this regard, this article focuses on critical analyses of the evidence from multiple studies on the efficacy of natural phytochemicals in BC. In addition, areas in which the combinations of such effective natural phytochemicals with approved and/or developing anticancer agents can be translationally beneficial are discussed to derive evidence-based inference for addressing challenges in BC control and therapy.

Limit cycle bifurcations in resonant LC power inverters under zero current switching strategy

The dynamics of a DC-AC self-oscillating LC resonant inverter with a zero current switching strategy is considered in this paper. A model that includes both the series and the parallel topologies and accounts for parasitic resistances in the energy storage components is used. It is found that only two reduced parameters are needed to unfold the bifurcation set of this extended system: one is related to the quality factor of the LC resonant tank, and the other accounts for the balance between serial and parallel losses. Through a rigorous mathematical study, a complete description of the bifurcation set is obtained and the parameter regions where the inverter can work properly is emphasized.

52 - Oxidizing Nano Particles (Smog) Induce Protective Levels of Proteasome via the Nrf2 Signal Transduction Pathway in Young but Not Old Female Mice

Environmental toxicants can act as accelerators of protein damage, with excess accumulation of protein aggregates promoting the aging process. Fortunately, organisms rely upon the adaptive homeostatic response to mitigate damage accumulation. The leading transcriptional activator associated with adaptation to oxidative stress is Nrf2, which upon nuclear translocation, can upregulate a plethora of stress responsive proteins, including the 20S proteasome. To understand the impact of environmental toxicants upon the adaptive homeostatic response in a mammalian mouse model, young (6 month) and middle-aged (21 month) female mice were exposed to either filtered air or reaerosolized vehicular-derived nanoparticulate (nPM) matter. Our findings suggest age and nPM exposure to impact the inducibility of the adaptive homeostatic response. Exposure to nPM in young tissue caused an adaptive increase in Nrf2 and its target genes. Conversely, nPM exposure in middle age, resulted in the lack of Nrf2-induction and increase in Nrf2 transcriptional inhibitors, Bach1 and c-Myc, accompanied with a parallel loss in adaptability of Nrf2-responsive genes, including the proteasome. These findings match a similar age-associated trend found in nPM-exposed male mice. More importantly, these results demonstrate the conserved trend of the age-dependent loss of the adaptive response , first demonstrated in the nematode worm and fruit fly, and now, in a mammalian mouse model.

Uncertainty propagation by using spectral methods: A practical application to a two-dimensional turbulence fluid model

To reduce the computational cost of the uncertainty propagation analysis, which is used to study the impact of input parameter variations on the results of a simulation, a general and simple to apply methodology based on decomposing the solution to the model equations in terms of Chebyshev polynomials is discussed. This methodology, based on the work by Scheffel [Am. J. Comput. Math. 2, 173–193 (2012)], approximates the model equation solution with a semi-analytic expression that depends explicitly on time, spatial coordinates, and input parameters. By employing a weighted residual method, a set of nonlinear algebraic equations for the coefficients appearing in the Chebyshev decomposition is then obtained. The methodology is applied to a two-dimensional Braginskii model used to simulate plasma turbulence in basic plasma physics experiments and in the scrape-off layer of tokamaks, in order to study the impact on the simulation results of the input parameter that describes the parallel losses. The uncertainty that characterizes the time-averaged density gradient lengths, time-averaged densities, and fluctuation density level are evaluated. A reasonable estimate of the uncertainty of these distributions can be obtained with a single reduced-cost simulation.

The emergence of Brazilian Portuguese: earlier evidence for the development of a partial null subject Grammar

Brazilian Portuguese (henceforth, BP) is currently analyzed as a partial null subject language (NSL). This work shows the earliest attested changes in the properties of null subjects in the Goias dialect of BP. We analyze original data from colonial period manuscripts written in Goias, a state located in Brazil's center-west region, and provide empirical evidence of the loss of null subjects in BP grammars in historical data between the 18th and 19th century, preceding the period for which these changes have been reported regarding other dialects of BP. The analysis of our 18th and 19th century corpus shows an early signifcant rise in the realization of overt subjects. In addition, the loss of verbsubject (VS) free inversion, a property common to NSLs, drops from 57% in the 18th century to only 22.5% in the 19th century. On the other hand, a potential impoverishment of the verbal paradigm did not play a signifcant role in this early rise of overt subjects: only 15% of the clauses with a plural external argument in the 19th century data did not show overt agreement between the verb and the external argument, and all of them occur strictly with unaccusative or existential verbs. We take this as evidence that the loss of null subjects in BP was primarily linked to the loss of free VS-inversion, and not to the loss of clausal agreement. We propose that D-feature in T (an EPP-feature) was valued by V-movement to T in the 18th century, yielding a consistent NSL. We argue that the loss of the requirement of the D-feature in T(tense) was a primary trigger for the partial loss of null subjects and parallel loss of free inversion from the 18th to the 19th century in Goias BP, giving then rise to a partial NSL (without a D-feature in T). --- DOI: http://dx.doi.org/10.31513/linguistica.2017.v13n2a14033

Discerning the Origins of the Negritos, First Sundaland People: Deep Divergence and Archaic Admixture.

Human presence in Southeast Asia dates back to at least 40,000 years ago, when the current islands formed a continental shelf called Sundaland. In the Philippine Islands, Peninsular Malaysia, and Andaman Islands, there exist indigenous groups collectively called Negritos whose ancestry can be traced to the “First Sundaland People.” To understand the relationship between these Negrito groups and their demographic histories, we generated genome-wide single nucleotide polymorphism data in the Philippine Negritos and compared them with existing data from other populations. Phylogenetic tree analyses show that Negritos are basal to other East and Southeast Asians, and that they diverged from West Eurasians at least 38,000 years ago. We also found relatively high traces of Denisovan admixture in the Philippine Negritos, but not in the Malaysian and Andamanese groups, suggesting independent introgression and/or parallel losses involving Denisovan introgressed regions. Shared genetic loci between all three Negrito groups could be related to skin pigmentation, height, facial morphology and malarial resistance. These results show the unique status of Negrito groups as descended from the First Sundaland People.

Effect of 3D magnetic perturbations on divertor conditions and detachment in tokamak and stellarator

Enhanced perpendicular heat and momentum transport induces parallel pressure loss leading to divertor detachment, which can be produced by the increase of density in 2D tokamaks. However, in the 3D configurations such as tokamaks with 3D fields and stellarators, the fraction of perpendicular transport can be higher even in a lower density regime, which could lead to the early transition to detachment without passing through the high-recycling regime. 3D fields applied to the limiter tokamak plasmas produce edge stochastic layers close to the last closed flux surface (LCFS), which can allow for enhanced perpendicular transport and indeed the absence of high recycling regime and early detachment have been observed in TEXTOR and Tore Supra. However, in the X-point divertor tokamaks with the applied 3D fields, the parallel transport is still dominant and the detachment facilitation has not been observed yet. Rather, 3D fields affected detachment adversely under certain conditions, either by preventing detachment onset as seen in DIII-D or by re-attaching the existing detached plasma as shown in NSTX. The possible way for strong 3D effects to induce access to the early detachment in divertor tokamaks appears to be via significant perpendicular loss of parallel momentum by frictional force for the counter-streaming flows between neighboring flow channels in the divertor. In principle, the adjacent lobes in the 3D divertor tokamak may generate the counter-streaming flow channels. However, an EMC3-EIRENE simulation for ITER H-mode plasmas demonstrated that screened RMP leads to significantly reduced counter-flows near the divertor target, therefore the momentum loss effect leading to detachment facilitation is expected to be small. This is consistent with the observation in LHD, which showed screening (amplification) of RMP fields in the attachment (stable detachment) case. Work for optimal parameter window for best divertor operation scenario is needed particularly for the 3D divertor tokamak configuration.

The emergence of Brazilian Portuguese: Earlier evidence for the development of a partial null subject grammar

Brazilian Portuguese (henceforth, BP) is currently analyzed as a partial null subject language (NSL). This work shows the earliest attested changes in the properties of null subjects in the Goiás dialect of Brazilian Portuguese. We analyze original data from colonial period manuscripts written in Goiás, a state located in Brazil’s center-west region, and provide empirical evidence of the loss of null subjects in BP grammars in historical data between the 18th and 19th century, preceding the period for which these changes have been reported regarding other dialects of BP. The analysis of our 18th and 19th century corpus shows an early significant rise in the realization of overt subjects. In addition, the loss of verb-subject (VS) free inversion, a property common to NSLs, drops from 57% in the 18th century to only 22.5% in the 19th century. On the other hand, a potential impoverishment of theverbal paradigm did not play a significant role in this early rise of overt subjects: only 15% of the clauses with a plural external argument in the 19th century data did not show overt agreement between the verb and the external argument, and all of them occur strictly with unaccusative or existential verbs. We take this as evidence that the loss of null subjects in BP was primarily linked to the loss of free VS-inversion, and not to the loss of clausal agreement. We propose that D-feature in T (an EPP-feature) was valued by V-movement to T in the 18th century, yielding a consistent NSL (Holmberg 2010). We argue that the loss of the requirement of the D-feature in T(tense) was a primary trigger for the partial loss of null subjects and parallel loss of free inversion from the 18th to the 19th century in Goiás BP, giving then rise to a partial NSL (without a D-feature in T).

Gyrokinetic continuum simulation of turbulence in a straight open-field-line plasma

Five-dimensional gyrokinetic continuum simulations of electrostatic plasma turbulence in a straight, open-field-line geometry have been performed using a full-$f$discontinuous-Galerkin approach implemented in the Gkeyll code. While various simplifications have been used for now, such as long-wavelength approximations in the gyrokinetic Poisson equation and the Hamiltonian, these simulations include the basic elements of a fusion-device scrape-off layer: localised sources to model plasma outflow from the core, cross-field turbulent transport, parallel flow along magnetic field lines, and parallel losses at the limiter or divertor with sheath-model boundary conditions. The set of sheath-model boundary conditions used in the model allows currents to flow through the walls. In addition to details of the numerical approach, results from numerical simulations of turbulence in the Large Plasma Device, a linear device featuring straight magnetic field lines, are presented.

Between a Pod and a Hard Test: The Deep Evolution of Amoebae.

Amoebozoa is the eukaryotic supergroup sister to Obazoa, the lineage that contains the animals and Fungi, as well as their protistan relatives, and the breviate and apusomonad flagellates. Amoebozoa is extraordinarily diverse, encompassing important model organisms and significant pathogens. Although amoebozoans are integral to global nutrient cycles and present in nearly all environments, they remain vastly understudied. We present a robust phylogeny of Amoebozoa based on broad representative set of taxa in a phylogenomic framework (325 genes). By sampling 61 taxa using culture-based and single-cell transcriptomics, our analyses show two major clades of Amoebozoa, Discosea, and Tevosa. This phylogeny refutes previous studies in major respects. Our results support the hypothesis that the last common ancestor of Amoebozoa was sexual and flagellated, it also may have had the ability to disperse propagules from a sporocarp-type fruiting body. Overall, the main macroevolutionary patterns in Amoebozoa appear to result from the parallel losses of homologous characters of a multiphase life cycle that included flagella, sex, and sporocarps rather than independent acquisition of convergent features.

Diverse genome organization following 13 independent mesopolyploid events in Brassicaceae contrasts with convergent patterns of gene retention.

Hybridization and polyploidy followed by genome-wide diploidization had a significant impact on the diversification of land plants. The ancient At-α whole-genome duplication (WGD) preceded the diversification of crucifers (Brassicaceae). Some genera and tribes also experienced younger, mesopolyploid WGDs concealed by subsequent genome diploidization. Here we tested if multiple base chromosome numbers originated due to genome diploidization after independent mesopolyploid WGDs and how diploidization affected post-polyploid gene retention. Sixteen species representing 10 Brassicaceae tribes were analyzed by comparative chromosome painting and/or whole-transcriptome analysis of gene age distributions and phylogenetic analyses of gene duplications. Overall, we found evidence for at least 13 independent mesopolyploidies followed by different degrees of diploidization across the Brassicaceae. New mesotetraploid events were uncovered for the tribes Anastaticeae, Iberideae and Schizopetaleae, and mesohexaploid WGDs for Cochlearieae and Physarieae. In contrast, we found convergent patterns of gene retention and loss among these independent WGDs. Our combined analyses of genomic data for Brassicaceae indicate that extant chromosome number variation in many plant groups, and especially monophyletic taxa with multiple base chromosome numbers, can result from clade-specific genome duplications followed by diploidization. Our observation of parallel gene retention and loss across multiple independent WGDs provides one of the first multi-species tests of the predictability of patterns of post-polyploid genome evolution.

Plasma pressure and particle loss studies in the Pilot-PSI high flux linear plasma generator

Plasma detachment in tokamak divertors reduces the particle and power fluxes to the plasma facing components and is essential for successful operation of ITER. The linear plasma generator Pilot-PSI can produce a high density (∼1021 m−3), low temperature (∼1eV) plasma which is similar to that expected at the ITER divertor strike-points during the partially detached regime [1]. Given the simple geometry of the device, Pilot-PSI allows to diagnose the plasma beam at multiple axial positions. In this study, the incoherent Thomson scattering (TS) diagnostic [2] is exploited to measure the radial plasma Te and ne profiles at two locations of the hydrogen plasma beam: near the plasma source (upstream) and 2cm from the target plate. At the target, the TS measurements are supported by an embedded Langmuir probe. These measurements prove the existence of parallel plasma pressure loss as well as particle loss, confirming that physical processes believed to cause detachment in tokamak divertors also hold in Pilot-PSI (ion-neutral friction, volume recombination). It is found that the fractional reduction of the plasma pressure varies between ∼4 and ∼5000, depending strongly on the pressure of the background neutrals. The importance of individual loss channels is discussed.