25 research outputs found
The neurogenic effects of exogenous neuropeptide Y: early molecular events and long-lasting effects in the hippocampus of trimethyltin-treated rats.
Modulation of endogenous neurogenesis is regarded as a promising challenge in neuroprotection. In the rat model of hippocampal neurodegeneration obtained by Trimethyltin (TMT) administration (8 mg/kg), characterised by selective pyramidal cell loss, enhanced neurogenesis, seizures and cognitive impairment, we previously demonstrated a proliferative role of exogenous neuropeptide Y (NPY), on dentate progenitors in the early phases of neurodegeneration. To investigate the functional integration of newly-born neurons, here we studied in adult rats the long-term effects of intracerebroventricular administration of NPY (2 \ub5g/2 \ub5l, 4 days after TMT-treatment), which plays an adjuvant role in neurodegeneration and epilepsy. Our results indicate that 30 days after NPY administration the number of new neurons was still higher in TMT+NPY-treated rats than in control+saline group. As a functional correlate of the integration of new neurons into the hippocampal network, long-term potentiation recorded in Dentate Gyrus (DG) in the absence of GABAA receptor blockade was higher in the TMT+NPY-treated group than in all other groups. Furthermore, qPCR analysis of Kruppel-like factor 9, a transcription factor essential for late-phase maturation of neurons in the DG, and of the cyclin-dependent kinase 5, critically involved in the maturation and dendrite extension of newly-born neurons, revealed a significant up-regulation of both genes in TMT+NPY-treated rats compared with all other groups. To explore the early molecular events activated by NPY administration, the Sonic Hedgehog (Shh) signalling pathway, which participates in the maintenance of the neurogenic hippocampal niche, was evaluated by qPCR 1, 3 and 5 days after NPY-treatment. An early significant up-regulation of Shh expression was detected in TMT+NPY-treated rats compared with all other groups, associated with a modulation of downstream genes. Our data indicate that the neurogenic effect of NPY administration during TMT-induced neurodegeneration involves early Shh pathway activation and results in a functional integration of newly-generated neurons into the local circuit
False data injection attacks against low voltage distribution systems
The transformation of the conventional electrical grid into a digital ecosystem brings significant benefits, such as two-way communication between energy consumers and utilities, self-monitoring and pervasive controls. However, the advent of the smart electrical grid raises severe cybersecurity and privacy concerns, given the presence of legacy systems and communications protocols. This paper focuses on False Data Injection (FDI) cyberattacks against a low-voltage distribution system, taking full advantage of Man In The Middle (MITM) actions. The first cyberattack targets the communication between a smart meter and an Active Distribution Management System (ADMS), while the second FDI cyberattack targets the communication between a smart inverter and ADMS. In both cases, the cyberattacks affect the operation of the distribution transformer, thus resulting in devastating consequences. Moreover, this paper provides an Artificial Intelligence (AI)-based Intrusion Detection System (IDS), detecting and mitigating the above cyberattacks in a timely manner. The evaluation results demonstrate the efficiency of the proposed IDS
Effect of Aliskiren on Circulating Endothelial Progenitor Cells and Vascular Function in Patients With Type 2 Diabetes and Essential Hypertension
BACKGROUND
The aim of this study was to investigate the effects of aliskiren on
vascular function and endothelial progenitor cells (EPCs) in patients
with type 2 diabetes and essential hypertension.
METHODS
The study enrolled type 2 diabetic patients aged > 50 years under stable
glycemic control and first diagnosed mild essential hypertension. In
phase A (n = 20), patients received aliskiren 150-300mg daily for 3
months. In phase B (n = 12), hydrochlorothiazide (HCTZ) 12.5-25mg daily
substituted for aliskiren for 3 more months. At baseline and at the end
of each phase, we assessed (i) brachial blood pressure (BBP); (ii)
central aortic systolic pressure (CSP), aortic augmentation index (Aix),
and pulse wave velocity (PWV) as markers of arterial stiffness; (iii)
brachial artery flow-mediated dilatation (FMD) as a marker of
endothelial function; (iv) left ventricular (LV) twisting and untwisting
as markers of LV function and (v) EPC numbers in culture of peripheral
blood mononuclear cells.
RESULTS
Aliskiren similarly reduced BBP and CSP, increased FMD (P < 0.001) and
EPC numbers (P < 0.001), decreased PWV and Aix (P < 0.05), and improved
LV twisting and untwisting (P < 0.05). Although substitution of HCTZ
sustained BBP at similar levels, CSP and echocardiographic indices
nearly returned at baseline levels, and the improvement of FMD, PWV,
Aix, and EPC numbers was abolished.
CONCLUSIONS
Aliskiren had a favorable effect on endothelial function and EPCs,
reduced arterial stiffness, and improved LV twisting and untwisting.
These effects were independent of BBP lowering, as they were not
observed after the achievement of similar values of BBP with HCTZ
Implication of lipoprotein associated phospholipase A2 activity in oxLDL uptake by macrophages
Recognition and uptake of oxidized LDL (oxLDL) by scavenger receptors of macrophages and foam cell formation are mediated by the oxidatively modified apolipoprotein B (ApoB) and lipid moiety of oxLDL. A great amount of oxidized phosphatidylcholine (oxPC) of oxLDL is hydrolyzed at the sn-2 position by lipoprotein associated phospholipase A2 (Lp-PLA2) to lysophosphatidylcholine and small oxidation products. This study examines the involvement of Lp-PLA2 in the uptake of oxLDL by mouse peritoneal macrophages. LDL with intact Lp-PLA2 activity [LDL (+)] and LDL with completely inhibited Lp-PLA2 activity [LDL (-)] were subjected to oxidation with 5 μM CuSO4 for 6 h [moderately oxLDL (MoxLDL)], or 24 h [heavily oxLDL (HoxLDL)] and peritoneal macrophages were incubated with these preparations. The uptake of MoxLDL(-) was about 30% increased compared with that of MoxLDL(+), and HoxLDL(-) uptake was about 20% increased compared with that of HoxLDL(+). Inhibition of Lp-PLA2 activity had no effect on the uptake of ApoB-liposomes conjugates with ApoB isolated from MoxLDL(-), MoxLDL(+), HoxLDL(-), and HoxLDL(+). Liposomes prepared from the lipid extract of MoxLDL(-), MoxLDL(+), HoxLDL(-), and HoxLDL(+) exhibited a similar pattern to that observed in the uptake of the corresponding intact lipoproteins. This study suggests that the progressive inactivation of Lp-PLA2 during LDL oxidation leads to an increased uptake of oxLDL by macrophages, which could be primarily attributed to the increased uptake of the oxidized phospholipids enriched lipid moiety of oxLDL
Waveform Modelling for the Laser Interferometer Space Antenna
International audienceLISA, the Laser Interferometer Space Antenna, will usher in a new era in gravitational-wave astronomy. As the first anticipated space-based gravitational-wave detector, it will expand our view to the millihertz gravitational-wave sky, where a spectacular variety of interesting new sources abound: from millions of ultra-compact binaries in our Galaxy, to mergers of massive black holes at cosmological distances; from the beginnings of inspirals that will venture into the ground-based detectors' view to the death spiral of compact objects into massive black holes, and many sources in between. Central to realising LISA's discovery potential are waveform models, the theoretical and phenomenological predictions of the pattern of gravitational waves that these sources emit. This white paper is presented on behalf of the Waveform Working Group for the LISA Consortium. It provides a review of the current state of waveform models for LISA sources, and describes the significant challenges that must yet be overcome