891 research outputs found
Butterflies (Lepidoptera) considered as threatened in Minas Gerais, Brazil
The twenty species of butterflies (diurnal Lepidoptera) considered as threatened in the Minas Gerais (by statute) are described and discussed in relation to distribution, appearance and known records.24125
The butterflies (Lepidoptera, Papilionoidea) of the Distrito Federal, Brazil
An updated list containing 504 species and 506 subspecies of butterflies (Papilionoidea) found in the Distrito Federal (central Brazil) in the last four decades is presented in this study, including data obtained in the literature, our personal collections, and several entomological collections recently visited, but not species with presumed distribution in the region. Some aspects concerning the occurrence of threatened species and the conservation of the butterfly fauna in the Distrito Federal are also discussed.Neste estudo é apresentada uma listagem atualizada com 504 espécies e 506 subespécies de borboletas (Papilionoidea) observadas no Distrito Federal nas últimas quatro décadas, onde foram reunidos dados da bibliografia, de coletas pessoais e de várias coleções entomológicas; espécies com ocorrência apenas presumida não foram incluídas. Alguns aspectos relacionados à ocorrência de espécies ameaçadas e à conservação da fauna de borboletas no Distrito Federal são também discutidos.859
An environmentally benign antimicrobial nanoparticle based on a silver-infused lignin core
Silver nanoparticles have antibacterial properties, but their use has been a cause for concern because they persist in the environment. Here, we show that lignin nanoparticles infused with silver ions and coated with a cationic polyelectrolyte layer form a biodegradable and green alternative to silver nanoparticles. The polyelectrolyte layer promotes the adhesion of the particles to bacterial cell membranes and, together with silver ions, can kill a broad spectrum of bacteria, including Escherichia coli, Pseudomonas aeruginosa and quaternary-amine-resistant Ralstonia sp. Ion depletion studies have shown that the bioactivity of these nanoparticles is time-limited because of the desorption of silver ions. High-throughput bioactivity screening did not reveal increased toxicity of the particles when compared to an equivalent mass of metallic silver nanoparticles or silver nitrate solution. Our results demonstrate that the application of green chemistry principles may allow the synthesis of nanoparticles with biodegradable cores that have higher antimicrobial activity and smaller environmental impact than metallic silver nanoparticles
Dysphoric milk ejection reflex: A case report
Dysphoric Milk Ejection Reflex (D-MER) is an abrupt emotional "drop" that occurs in some women just before milk release and continues for not more than a few minutes. The brief negative feelings range in severity from wistfulness to self-loathing, and appear to have a physiological cause. The authors suggest that an abrupt drop in dopamine may occur when milk release is triggered, resulting in a real or relative brief dopamine deficit for affected women. Clinicians can support women with D-MER in several ways; often, simply knowing that it is a recognized phenomenon makes the condition tolerable. Further study is needed
Gluon-gluon contributions to W+ W- production and Higgs interference effects
In this paper we complete our re-assessment of the production of W boson
pairs at the LHC, by calculating analytic results for the gg -> W+ W- -> (\nu l
l\nu) process including the effect of massive quarks circulating in the loop.
Together with the one-loop amplitudes containing the first two generations of
massless quarks propagating in the loop, these diagrams can give a significant
contribution with a large flux of gluons. One of the component parts of this
calculation is the production of a standard model Higgs boson, gg -> H and its
subsequent decay, H -> W+(-> \nu l) W-(-> l \nu). We will quantify the
importance of the interference between the Higgs boson production process and
the gluon-induced continuum production in the context of searches for the Higgs
boson at the Tevatron and the LHC. For instance, for mH < 140 GeV the effect of
the interference typically results in around a 10% reduction in the expected
number of Higgs signal events. The majority of this interference is due to
non-resonant contributions. Therefore cuts on the transverse mass such as those
currently used by the ATLAS collaboration reduce the destructive interference
to about a 1% effect. We advocate that a cut on the maximum transverse mass be
used in future Higgs searches in this channel
Herpesvirus Telomerase RNA (vTR) with a Mutated Template Sequence Abrogates Herpesvirus-Induced Lymphomagenesis
Telomerase reverse transcriptase (TERT) and telomerase RNA (TR) represent the enzymatically active components of telomerase. In the complex, TR provides the template for the addition of telomeric repeats to telomeres, a protective structure at the end of linear chromosomes. Human TR with a mutation in the template region has been previously shown to inhibit proliferation of cancer cells in vitro. In this report, we examined the effects of a mutation in the template of a virus encoded TR (vTR) on herpesvirus-induced tumorigenesis in vivo. For this purpose, we used the oncogenic avian herpesvirus Marek's disease virus (MDV) as a natural virus-host model for lymphomagenesis. We generated recombinant MDV in which the vTR template sequence was mutated from AATCCCAATC to ATATATATAT (vAU5) by two-step Red-mediated mutagenesis. Recombinant viruses harboring the template mutation replicated with kinetics comparable to parental and revertant viruses in vitro. However, mutation of the vTR template sequence completely abrogated virus-induced tumor formation in vivo, although the virus was able to undergo low-level lytic replication. To confirm that the absence of tumors was dependent on the presence of mutant vTR in the telomerase complex, a second mutation was introduced in vAU5 that targeted the P6.1 stem loop, a conserved region essential for vTR-TERT interaction. Absence of vTR-AU5 from the telomerase complex restored virus-induced lymphoma formation. To test if the attenuated vAU5 could be used as an effective vaccine against MDV, we performed vaccination-challenge studies and determined that vaccination with vAU5 completely protected chickens from lethal challenge with highly virulent MDV. Taken together, our results demonstrate 1) that mutation of the vTR template sequence can completely abrogate virus-induced tumorigenesis, likely by the inhibition of cancer cell proliferation, and 2) that this strategy could be used to generate novel vaccine candidates against virus-induced lymphoma
Reverberation mapping of optical emission lines in five active galaxies
For a video summarizing the main results, see https://www.youtube.com/watch?v=KaC-jPsIY0QWe present the first results from an optical reverberation mapping campaign executed in 2014 targeting the active galactic nuclei (AGNs) MCG+08-11-011, NGC 2617, NGC 4051, 3C 382, and Mrk 374. Our targets have diverse and interesting observational properties, including a "changing look" AGN and a broad-line radio galaxy. Based on continuum-Hβ lags, we measure black hole masses for all five targets. We also obtain Hγ and He ii λ4686 lags for all objects except 3C 382. The He ii λ4686 lags indicate radial stratification of the BLR, and the masses derived from different emission lines are in general agreement. The relative responsivities of these lines are also in qualitative agreement with photoionization models. These spectra have extremely high signal-to-noise ratios (100–300 per pixel) and there are excellent prospects for obtaining velocity-resolved reverberation signatures.Publisher PDFPeer reviewe
SMF-1, SMF-2 and SMF-3 DMT1 Orthologues Regulate and Are Regulated Differentially by Manganese Levels in C. elegans
Manganese (Mn) is an essential metal that can exert toxic effects at high concentrations, eventually leading to Parkinsonism. A major transporter of Mn in mammals is the divalent-metal transporter (DMT1). We characterize here DMT1-like proteins in the nematode C. elegans, which regulate and are regulated by Mn and iron (Fe) content. We identified three new DMT1-like genes in C. elegans: smf-1, smf-2 and smf-3. All three can functionally substitute for loss of their yeast orthologues in S. cerevisiae. In the worm, deletion of smf-1 or smf-3 led to an increased Mn tolerance, while loss of smf-2 led to increased Mn sensitivity. smf mRNA levels measured by QRT-PCR were up-regulated upon low Mn and down-regulated upon high Mn exposures. Translational GFP-fusions revealed that SMF-1 and SMF-3 strongly localize to partially overlapping apical regions of the gut epithelium, suggesting a differential role for SMF-1 and SMF-3 in Mn nutritional intake. Conversely, SMF-2 was detected in the marginal pharyngeal epithelium, possibly involved in metal-sensing. Analysis of metal content upon Mn exposure in smf mutants revealed that SMF-3 is required for normal Mn uptake, while smf-1 was dispensable. Higher smf-2 mRNA levels correlated with higher Fe content, supporting a role for SMF-2 in Fe uptake. In smf-1 and smf-3 but not in smf-2 mutants, increased Mn exposure led to decreased Fe levels, suggesting that both metals compete for transport by SMF-2. Finally, SMF-3 was post-translationally and reversibly down-regulated following Mn-exposure. In sum, we unraveled a complex interplay of transcriptional and post-translational regulations of 3 DMT1-like transporters in two adjacent tissues, which regulate metal-content in C. elegans
RESTORE-IMI 1: A Multicenter, Randomized, Doubleblind Trial Comparing Efficacy and Safety of Imipenem/Relebactam vs Colistin Plus Imipenem in Patients With Imipenem-nonsusceptible Bacterial Infections
Background. The β-lactamase inhibitor relebactam can restore imipenem activity against imipenem-nonsusceptible gram-negative pathogens. We evaluated imipenem/relebactam for treating imipenem-nonsusceptible infections.
Methods. Randomized, controlled, double-blind, phase 3 trial. Hospitalized patients with hospital-acquired/ventilatorassociated pneumonia, complicated intraabdominal infection, or complicated urinary tract infection caused by imipenemnonsusceptible (but colistin- and imipenem/relebactam-susceptible) pathogens were randomized 2:1 to 5–21 days imipenem/
relebactam or colistin+imipenem. Primary endpoint: favorable overall response (defined by relevant endpoints for each infection
type) in the modified microbiologic intent-to-treat (mMITT) population (qualifying baseline pathogen and ≥1 dose study treatment). Secondary endpoints: clinical response, all-cause mortality, and treatment-emergent nephrotoxicity. Safety analyses included
patients with ≥1 dose study treatment.
Results. Thirty-one patients received imipenem/relebactam and 16 colistin+imipenem. Among mITT patients (n = 21
imipenem/relebactam, n = 10 colistin+imipenem), 29% had Acute Physiology and Chronic Health Evaluation II scores >15, 23%
had creatinine clearance <60 mL/min, and 35% were aged ≥65 years. Qualifying baseline pathogens: Pseudomonas aeruginosa (77%),
Klebsiella spp. (16%), other Enterobacteriaceae (6%). Favorable overall response was observed in 71% imipenem/relebactam and
70% colistin+imipenem patients (90% confidence interval [CI] for difference, –27.5, 21.4), day 28 favorable clinical response in 71%
and 40% (90% CI, 1.3, 51.5), and 28-day mortality in 10% and 30% (90% CI, –46.4, 6.7), respectively. Serious adverse events (AEs)
occurred in 10% of imipenem/relebactam and 31% of colistin+imipenem patients, drug-related AEs in 16% and 31% (no drugrelated deaths), and treatment-emergent nephrotoxicity in 10% and 56% (P = .002), respectively.
Conclusions. Imipenem/relebactam is an efficacious and well-tolerated treatment option for carbapenem-nonsusceptible
infection
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