741 research outputs found
Genomic and molecular characterization of a novel quorum sensing molecule in Bacillus licheniformis
Quorum sensing molecules (QSMs) are involved in the regulation of complicated processes helping bacterial populations respond to changes in their cell-density. Although the QS gene cluster (comQXPA) has been identified in the genome sequence of some bacilli, the QS system B. licheniformis has not been investigated in detail, and its QSM (ComX pheromone) has not been identified. Given the importance of this antagonistic bacterium as an industrial workhorse, this study was aimed to elucidate B. licheniformis NCIMB-8874 QS. The results obtained from bioinformatics studies on the whole genome sequence of this strain confirmed the presence of essential quorum sensing-related genes. Although polymorphism was verified in three proteins of this cluster, ComQ, precursor-ComX and ComP, the transcription factor ComA was confirmed as the most conserved protein. The cell–cell communication of B. licheniformis NCIMB-8874 was investigated through further elucidation of the ComX pheromone as 13-amino acid peptide. The peptide sequence of the pheromone has been described through biochemical characterisation
Retinal ganglion cell survival and axon regeneration in WldS transgenic rats after optic nerve crush and lens injury.
BACKGROUND: We have previously shown that the slow Wallerian degeneration mutation, whilst delaying axonal degeneration after optic nerve crush, does not protect retinal ganglion cell (RGC) bodies in adult rats. To test the effects of a combination approach protecting both axons and cell bodies we performed combined optic nerve crush and lens injury, which results in both enhanced RGC survival as well as axon regeneration past the lesion site in wildtype animals. RESULTS: As previously reported we found that the Wld(S) mutation does not protect RGC bodies after optic nerve crush alone. Surprisingly, we found that Wld(S) transgenic rats did not exhibit the enhanced RGC survival response after combined optic nerve crush and lens injury that was observed in wildtype rats. RGC axon regeneration past the optic nerve lesion site was, however, similar in Wld(S) and wildtypes. Furthermore, activation of retinal glia, previously shown to be associated with enhanced RGC survival and axon regeneration after optic nerve crush and lens injury, was unaffected in Wld(S) transgenic rats. CONCLUSIONS: RGC axon regeneration is similar between Wld(S) transgenic and wildtype rats, but Wld(S) transgenic rats do not exhibit enhanced RGC survival after combined optic nerve crush and lens injury suggesting that the neuroprotective effects of lens injury on RGC survival may be limited by the Wld(S) protein.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Towards Practical Fabrication Stage Attacks Using Interrupt-Resilient Hardware Trojans
We introduce a new class of hardware trojans called interrupt-resilient
trojans (IRTs). Our work is motivated by the observation that hardware trojan
attacks on CPUs, even under favorable attack scenarios (e.g., an attacker with
local system access), are affected by unpredictability due to non-deterministic
context switching events. As we confirm experimentally, these events can lead
to race conditions between trigger signals and the CPU events targeted by the
trojan payloads (e.g., a CPU memory access), thus affecting the reliability of
the attacks. Our work shows that interrupt-resilient trojans can successfully
address the problem of non-deterministic triggering in CPUs, thereby providing
high reliability guarantees in the implementation of sophisticated hardware
trojan attacks. Specifically, we successfully utilize IRTs in different attack
scenarios against a Linux-capable CPU design and showcase its resilience
against context-switching events. More importantly, we show that our design
allows for seamless integration during fabrication stage attacks.We evaluate
different strategies for the implementation of our attacks on a tape-out ready
high-speed RISC-V microarchitecture in a 28nm commercial technology process and
successfully implement them with an average overhead delay of only 20
picoseconds, while leaving the sign-off characteristics of the layout intact.
In doing so, we challenge the common wisdom regarding the low flexibility of
late supply chain stages (e.g., fabrication) for the insertion of powerful
trojans. To promote further research on microprocessor trojans, we open-source
our designs and provide the accompanying supporting software logic
MicroRNAs in pulmonary arterial remodeling
Pulmonary arterial remodeling is a presently irreversible pathologic hallmark of pulmonary arterial hypertension (PAH). This complex disease involves pathogenic dysregulation of all cell types within the small pulmonary arteries contributing to vascular remodeling leading to intimal lesions, resulting in elevated pulmonary vascular resistance and right heart dysfunction. Mutations within the bone morphogenetic protein receptor 2 gene, leading to dysregulated proliferation of pulmonary artery smooth muscle cells, have been identified as being responsible for heritable PAH. Indeed, the disease is characterized by excessive cellular proliferation and resistance to apoptosis of smooth muscle and endothelial cells. Significant gene dysregulation at the transcriptional and signaling level has been identified. MicroRNAs are small non-coding RNA molecules that negatively regulate gene expression and have the ability to target numerous genes, therefore potentially controlling a host of gene regulatory and signaling pathways. The major role of miRNAs in pulmonary arterial remodeling is still relatively unknown although research data is emerging apace. Modulation of miRNAs represents a possible therapeutic target for altering the remodeling phenotype in the pulmonary vasculature. This review will focus on the role of miRNAs in regulating smooth muscle and endothelial cell phenotypes and their influence on pulmonary remodeling in the setting of PAH
Eye and Periocular Skin Involvement in Herpes Zoster Infection
Herpes zoster ophthalmicus (HZO) is a clinical manifestation of the reactivation of latent varicella zoster virus (VZV) infection and is more common in people with diminished cell-mediated immunity. Lesions and pain correspond to the affected dermatomes, mostly in first or second trigeminal branch and progress from maculae, papules to vesicles and form pustules, and crusts. Complications are cutaneous, visceral, neurological, ocular, but the most debilitating is post-herpetic neuralgia. Herpes zoster ophthalmicus may affect all the ophthalmic structures, but most severe eye-threatening complications are panuveitis, acute retinal necrosis (ARN) and progressive outer retinal necrosis (PORN) as well. Antiviral medications remain the primary therapy, mainly useful in preventing ocular involvement when begun within 72 hours after the onset of the rash. Timely diagnosis and management of HZO are critical in limiting visual morbidity. Vaccine in adults over 60 was found to be highly effective to boost waning immunity what reduces both the burden of herpes zoster (HZ) disease and the incidence of post-herpetic neuralgia (PHN)
Eye and Periocular Skin Involvement in Herpes Zoster Infection
Herpes zoster ophthalmicus (HZO) is a clinical manifestation of the reactivation of latent varicella zoster virus (VZV) infection and is more common in people with diminished cell-mediated immunity. Lesions and pain correspond to the affected dermatomes, mostly in first or second trigeminal branch and progress from maculae, papules to vesicles and form pustules, and crusts. Complications are cutaneous, visceral, neurological, ocular, but the most debilitating is post-herpetic neuralgia. Herpes zoster ophthalmicus may affect all the ophthalmic structures, but most severe eye-threatening complications are panuveitis, acute retinal necrosis (ARN) and progressive outer retinal necrosis (PORN) as well. Antiviral medications remain the primary therapy, mainly useful in preventing ocular involvement when begun within 72 hours after the onset of the rash. Timely diagnosis and management of HZO are critical in limiting visual morbidity. Vaccine in adults over 60 was found to be highly effective to boost waning immunity what reduces both the burden of herpes zoster (HZ) disease and the incidence of post-herpetic neuralgia (PHN)
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