Giant viruses continue to invade the world of virology, in gigantic genome sizes and various particles shapes. Strains discoveries and metagenomic studies make it possible to reveal the complexity of ...these microorganisms, their origins, ecosystems and putative roles. We isolated from a rat stool sample a new giant virus "Orpheovirus IHUMI-LCC2," using
as host cell. In this paper, we describe the main genomic features and replicative cycle of Orpheovirus IHUMI-LCC2. It possesses a circular genome exceeding 1.4 Megabases with 25% G+C content and ovoidal-shaped particles ranging from 900 to 1300 nm. Particles are closed by at least one thick membrane in a single ostiole-like shape in their apex. Phylogenetic analysis and the reciprocal best hit for Orpheovirus show a connection to the proposed
family. However, some genomic characteristics bear witness to a completely divergent evolution for Orpheovirus IHUMI-LCC2 when compared to Cedratviruses or Pithoviruses.
Cyclodipeptide synthases (CDPSs) use as substrates two amino acids activated as aminoacyl-tRNAs to synthesize cyclodipeptides in secondary metabolites biosynthetic pathways. Since the first ...description of a CDPS in 2002, the number of putative CDPSs in databases has increased exponentially, reaching around 800 in June 2017. They are likely to be involved in numerous biosynthetic pathways but the diversity of their products is still under-explored. Here, we describe the activity of 32 new CDPSs, bringing the number of experimentally characterized CDPSs to about 100. We detect 16 new cyclodipeptides, one of which containing an arginine which has never been observed previously. This brings to 75 the number of cyclodipeptides formed by CDPSs out of the possible 210 natural ones. We also identify several consensus sequences related to the synthesis of a specific cyclodipeptide, improving the predictive model of CDPS specificity. The improved prediction method enables to propose the main product synthesized for about 80% of the CDPS sequences available in databases and opens the way for the deciphering of CDPS-dependent pathways. Analysis of phylum distribution and predicted activity for all CDPSs identified in databases shows that the experimentally characterized set is representative of the whole family. Our work also demonstrates that some cyclodipeptides, precursors of diketopiperazines with interesting pharmacological properties and previously described as being synthesized by fungal non-ribosomal peptide synthetases, can also be produced by CDPSs in bacteria.
Autonomous vehicles use sensors and artificial intelligence to drive themselves. Surveys indicate that people are fascinated by the idea of autonomous driving, but are hesitant to relinquish control ...of the vehicle. Lack of trust seems to be the core reason for these concerns. In order to address this, an intelligent agent approach was implemented, as it has been argued that human traits increase trust in interfaces. Where other approaches mainly use anthropomorphism to shape appearances, the current approach uses anthropomorphism to shape the interaction, applying Gricean maxims (i.e., guidelines for effective conversation). The contribution of this approach was tested in a simulator that employed both a graphical and a conversational user interface, which were rated on likability, perceived intelligence, trust, and anthropomorphism. Results show that the conversational interface was trusted, liked, and anthropomorphized more, and was perceived as more intelligent, than the graphical user interface. Additionally, an interface that was portrayed as more confident in making decisions scored higher on all four constructs than one that was portrayed as having low confidence. These results together indicate that equipping autonomous vehicles with interfaces that mimic human behavior may help increasing people’s trust in, and, consequently, their acceptance of them.
The mechanisms that control cell proliferation and cell differentiation during morphogenesis of the endochondral skeleton of vertebrates are poorly understood. Indian hedgehog (Ihh) signaling from ...prehypertrophic chondrocytes has been implicated in the control of chondrocyte maturation by way of feedback control of a second secreted factor parathyroid hormone-related peptide (PTHrP) at the articular surfaces. Analysis of an Ihh null mutant suggests a more extensive role for Ihh in skeletal development. Mutants display markedly reduced chondrocyte proliferation, maturation of chondrocytes at inappropriate position, and a failure of osteoblast development in endochondral bones. Together, the results suggest a model in which Ihh coordinates diverse aspects of skeletal morphogenesis through PTHrP-dependent and independent processes.
The 52 mg hormonal-IUD who were at menopausal transition reported worries that the use of the IUD can affect menopausal symptoms. It is important that health professionals can routinely guide these ...women.
To assess perimenopausal users of 52 mg levonorgestrel intrauterine devices (LNG-IUD) regarding the IUD impact after menopause.
a cross-sectional study with users aged 40 and 49 years old, without cognitive impairment that answered a questionnaire regarding worries and benefits after the menopause due to LNG-IUD use.
Almost half of 221 users (52.9%) have concerns that LNG-IUD use could influence aspects after menopause, 111 (50.3%) that the post-menopause symptoms get worse and 92 (41.6%) that interfere with recognition of menopausal symptoms.
Half of perimenopausal LNG-IUD users expressed concerns about how device use could affect post-menopause symptoms.
Understanding the impact of pollutant ozone (O
3) is a concern for agricultural production. This work was undertaken as the first comparative study of the effects of O
3 on the photosynthetic ...processes and yield of three snap bean (
Phaseolus vulgaris L.) genotypes with known differences in sensitivity to O
3 (S156, R123 and R331). Previous information showed R123 and R331 to be tolerant and S156 sensitive. The purpose was to identify physiological subsystems that may mediate those differences in sensitivity. Plants were grown in environmentally controlled field chambers with four levels of O
3 (0, 15, 30 and 60
nmol
mol
−1). Net assimilation (
A) and fluorescence were measured throughout the growing season and yield data were collected at physiological maturity. All genotypes were tolerant of low O
3 (<30
nmol
mol
−1) but the highest O
3 significantly reduced the yield in all three, with R331 and S156 being equally sensitive on a unit exposure basis. Yield reductions were correlated with A, especially during pod filling. No genotype showed any significant response of stomatal conductance (
g
s) indicating equal O
3 fluxes into the leaves in all genotypes. Mesophyll conductance (
g
m) was affected in S156 only, where it was reduced by 55% at 60
nmol
mol
−1 O
3. There was an upward trend in
F
0, and a downward trend in the variable fluorescence ratio (
F
v/
F
m) with increasing O
3 for S156 but not for the other genotypes. S156 was the only genotype to show significant decreases in photochemical quenching (
q
p) and R123 the only one to show significant decreases in non-photochemical quenching (
q
n). The sequence of loss of Rubisco content and/or activity and changes in
g
m,
F
0, and
F
v/
F
m could not be resolved in time and may all have been the result of generalized tissue destruction rather than sequential attack on individual subsystems. S156 had the highest photosynthetic rate in clean air but appeared to have no significant capacity to protect Rubisco from attack or to up-regulate Rubisco activity at high O
3, thus there was no reserve capacity, while R123 was able to maintain both Rubisco activity and
A within narrow ranges. These data suggest that S156 has comparatively little anti-oxidant capacity and/or is deficient in its ability to regulate Rubisco activity. For future studies the best contrasts for resolving questions of physiological sensitivity to O
3 would be obtained from R123 and S156.
Pancreas organogenesis is regulated by the interaction of distinct signaling pathways that promote or restrict morphogenesis and cell differentiation. Previous work has shown that activin, a ...TGF(beta+) signaling molecule, permits pancreas development by repressing expression of Sonic hedgehog (Shh), a member of the hedgehog family of signaling molecules that antagonize pancreas development. Here we show that Indian hedgehog (Ihh), another hedgehog family member, and Patched 1 (Ptc1), a receptor and negative regulator of hedgehog activity, are expressed in pancreatic tissue. Targeted inactivation of Ihh in mice allows ectopic branching of ventral pancreatic tissue resulting in an annulus that encircles the duodenum, a phenotype frequently observed in humans suffering from a rare disorder known as annular pancreas. Shh(-)(/)(-) and Shh(-)(/)(-) Ihh(+/)(-) mutants have a threefold increase in pancreas mass, and a fourfold increase in pancreatic endocrine cell numbers. In contrast, mutations in Ptc1 reduce pancreas gene expression and impair glucose homeostasis. Thus, islet cell, pancreatic mass and pancreatic morphogenesis are regulated by hedgehog signaling molecules expressed within and adjacent to the embryonic pancreas. Defects in hedgehog signaling may lead to congenital pancreatic malformations and glucose intolerance.
The Megavirales are a newly described order capable of infecting different types of eukaryotic hosts. For the most part, the natural host is unknown. Several methods have been used to detect these ...viruses, with large discrepancies between molecular methods and co-cultures. To isolate giant viruses, we propose the use of different species of amoeba as a cellular support. The aim of this work was to isolate new Brazilian giant viruses by comparing the protozoa Acanthamoeba castellanii, A. polyphaga, A. griffini, and Vermamoeba vermiformis (VV) as a platform for cellular isolation using environmental samples. One hundred samples were collected from 3 different areas in September 2014 in the Pampulha lagoon of Belo Horizonte city, Minas Gerais, Brazil. PCR was used to identify the isolated viruses, along with hemacolor staining, labelling fluorescence and electron microscopy. A total of 69 viruses were isolated. The highest ratio of isolation was found in A. polyphaga (46.38%) and the lowest in VV (0%). Mimiviruses were the most frequently isolated. One Marseillevirus and one Pandoravirus were also isolated. With Brazilian environmental samples, we demonstrated the high rate of lineage A mimiviruses. This work demonstrates how these viruses survive and circulate in nature as well the differences between protozoa as a platform for cellular isolation.
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