Molecular criteria for discriminating adipose fat and milk from different species by NanoESI MS and MS/MS of their triacylglycerols: application to archaeological remains

A new multistep analytical methodology is described in this paper for the precise identification of triacylglycerols, which are biomarkers of dairy products and subcutaneous fats, that may be chemically identified in archaeological pottery. It consists of the analysis of the total lipid extract from different kinds of fats by high-temperature gas chromatography, performed in order to select the ceramic vessels in which animal fats are well preserved, followed by nanoelectrospray QqTOF mass spectrometry that allows for distinguishing the specific origins of the lipids detected (namely, cow, sheep, or goat). The analysis of model samples, cow and goat dairy products and cow and sheep adipose fats, was successfully achieved. The fatty acid composition of each triacylglycerol was identified, which allowed for the discrimination of subcutaneous fats and dairy fats and distinguishing between cow and goat milk. This methodology was then applied to archaeological samples, and the presence of goat milk, cow milk, and possibly sheep subcutaneous fat was assessed based on the discriminating criteria found on modern fats.     

The C-Terminal Domain of LRRK2 with the G2019S Substitution Increases Mutant A53T α-Synuclein Toxicity in Dopaminergic Neurons In Vivo

Alpha-synuclein (α-syn) and leucine-rich repeat kinase 2 (LRRK2) play crucial roles in Parkinson’s disease (PD). They may functionally interact to induce the degeneration of dopaminergic (DA) neurons via mechanisms that are not yet fully understood. We previously showed that the C-terminal portion of LRRK2 (ΔLRRK2) with the G2019S mutation (ΔLRRK2^G2019S) was sufficient to induce neurodegeneration of DA neurons in vivo, suggesting that mutated LRRK2 induces neurotoxicity through mechanisms that are (i) independent of the N-terminal domains and (ii) “cell-autonomous”. Here, we explored whether ΔLRRK2^G2019S could modify α-syn toxicity through these two mechanisms. We used a co-transduction approach in rats with AAV vectors encoding ΔLRRK2^G2019S or its “dead” kinase form, ΔLRRK2^DK, and human α-syn with the A53T mutation (AAV-α-syn^A53T). Behavioral and histological evaluations were performed at 6- and 15-weeks post-injection. Results showed that neither form of ΔLRRK2 alone induced the degeneration of neurons at these post-injection time points. By contrast, injection of AAV-α-syn^A53T alone resulted in motor signs and degeneration of DA neurons. Co-injection of AAV-α-syn^A53T with AAV-ΔLRRK2^G2019S induced DA neuron degeneration that was significantly higher than that induced by AAV-α-syn^A53T alone or with AAV-ΔLRRK2^DK. Thus, mutated α-syn neurotoxicity can be enhanced by the C-terminal domain of LRRK2^G2019 alone^, through cell-autonomous mechanisms.     

Prevalence and distribution of Listeria monocytogenes serotypes and pulsotypes in sows and fattening pigs in farrow-to-finish farms (France, 2008)

This study was undertaken to acquire new data on the prevalence of Listeria monocytogenes in sows and fattening pigs in farrow-to-finish pig farms, and to analyze distribution of serotypes and genotypes of the bacterium within farms. Detection of L. monocytogenes was carried out on 730 pooled feces samples from sows in 73 pig farms and on 172 pooled feces samples from fattening pigs in 43 of these farms. Isolates were serotyped and typed by pulsed-field gel electrophoresis. For sows, 46% of the farms and 11% of the samples were positive for L. monocytogenes. A total of 124 isolates were collected and distributed in four serotypes: 1/2a (41%), 1/2b (36%), 4b (21%), and 1/2c (2%). Positive farms harbored one to three serotypes. The genetic diversity was high; 51 genetic profiles were obtained with 25, 16, 9, and 1 for the serotypes 1/2a, 1/2b, 4b, and 1/2c, respectively. Positive farms harbored 1 to 6 genetic profiles. Isolates showing similar genotypes occurred in several farms. For fattening pigs, 25% of the farms and 14.5% of the samples were positive for L. monocytogenes. The 34 isolates belonged to four serotypes: 1/2a (32%), 1/2b (41%), 4b (24%), and 1/2c (3%). They were distributed in 20 genotypes: 6 for 1/2a; 8 for 1/2b, 5 for 4b, and 1 for 1/2c. Similar serotypes and pulsotypes were recovered in sows and fattening pigs from the same farms, suggesting common sources of contamination.     

Arteriovenous fistula for the 80 years and older patients on hemodialysis: Is it worth it?

Over the last years, the proportion of patients older than 80 years with end‐stage renal disease has been constantly growing. Arteriovenous fistula (AVF) is known as the best vascular access for hemodialysis, but evidence for its added value is lacking for elderly. We retrospectively identified new vascular access (AVF and central venous catheter) created or installed between June 2005 and June 2008 in patients 80 years and older and in patients between 50 and 60 years. For every new AVF, we calculated primary failure, primary and secondary patency durations. Fifty‐five and 57 patients had a new vascular access in the >80 years old and 50 to 60 years old groups. Among these, 25 and 41 were new AVF in the older and younger groups. Primary failure was more frequent in elderly than in the younger (40% vs. 17%, P = 0.04). Primary patency was not significantly different in both groups (P = 0.06). Secondary patency was shorter in elderly (P = 0.005). Among the older group, the presence of an AVF was not associated with a difference in mortality (46% vs. 60%, P = 0.28), whereas there was a lower mortality in the younger group with AVF (12% vs. 43% P = 0.008). These results indicate lower patency duration in very elderly patients compared to middle‐aged patients. Without leading to the exclusion of patients over 80 years old for AVF creation, it might reinforce the need of a careful selection and evaluation in this population prior to referral.     

Hybrid Dual-Mode Frequency Synthesis for Cognitive Multi-radio Front-Ends

This paper investigates a novel approach to reconfigurable frequency synthesis for flexible radio transceivers in future cognitive multi-radios. The frequency range covered by the proposed multi-radio synthesizer corresponds to the frequency bands of the most diffused wireless communication standards operating in the radio band ranging from 800 MHz to 6 GHz. A hybrid phase locked loop (PLL) based frequency synthesizer is proposed here and a novel switching protocol is presented and validated on an experimental evaluation board. The proposed architecture combines fractional and integer PLL modes of operation along with a switched loop filter topology. Compared to standard PLL techniques, the proposed configuration provides great flexibility options and moreover, it offers relatively low circuit complexity and low power consumption. The proposed architecture provides reconfigurability of the loop bandwidth, frequency resolution, phase noise and settling time performance and hence, it can adapt itself to diverse requirements given by the concerned wireless communication standards.     

Joint channel and phase noise estimation in OFDM systems at very high speeds

In this paper, the problem of joint phase noise and channel estimation for OFDM systems over a fast time-varying frequency-selective channel is explored. Each channel tap time-variation within one OFDM symbol is approximated by a Basis Expansion Model (BEM). Joint estimation is performed on multiple OFDM symbols via the Extended Kalman Filtering in order to exploit the time-correlation of the parameters. The data symbols are estimated by means of an iterative pilot-based algorithm. It is shown that, with only 2 iterations, our algorithm outperforms the conventional one, and the performance approaches that of the ideal case for which the channel response and phase noise are known.     

Marine diatom Navicula jeffreyi from biochemical composition and physico-chemical surface properties to understanding the first step of benthic biofilm formation

To understand the first step of marine benthic microbial mat formation and biofouling phenomena, caused by diatoms in the marine environment, the surface properties of the epipelic diatom Navicula jeffreyi were studied and the composition of its bound Extracellular Polymeric Substances (EPS) was determined. These parameters are determining factors for the initial adhesion step of diatoms to other constituents that start marine fouling. Surface energy of a diatom cell layer was determined using the sessile drop technique and highlights that diatoms show a moderate hydrophobic character (contact angle with water >68°), no Lewis acid character (γ⁺?<1?mJ/m²), and a low Lewis basic character (γ^??=?16.1?mJ/m²). An extraction procedure using a cationic resin subtracted only the bound EPS. Biochemical assays showed that there were 2.5 times more proteins than sugars. The propensity of Navicula jeffreyi diatom to adhere to five different solid surfaces, showing a gradient in their hydrophobic and hydrophilic character, was measured. The attachment densities were high on hydrophobic surfaces such as polytetrafluoroethylene and very low on substrata with surface free energy over 40–50?mJ/m². Using a thermodynamic approach, the free energy of adhesion of the diatom to the five substrata was determined, and led to a very strong correlation with attachment densities for polytetrafluoroethylene, polyamide, polyethylene, and stainless steel.     

Approach of phase transformations and densification in nanostructured and (Bi2O3, ZnO,TiO2) doped silica ceramics

The low temperature sintering of silica is studied under the influence of sintering aids and nanosized powders using X-Ray Diffractometry (XRD) and high-temperature environmental scanning electron microscopy analyses (HT-ESEM). Two particular aids were chosen to conduct this study, [Bi₂O₃–ZnO]_eutectic and titania. We report a lowering of the crystallization temperature when the former compound is introduced in the silica while a raise is observed when the latter is used. Moreover, the amorphous silica crystallization into cristobalite inhibits drastically the kinetics of densification of silica-based materials.     

Atmospheric Effects on the Performance of CdZnTe Single-Crystal Detectors

The production of high-quality ternary single-crystal materials for radiation detectors has progressed over the past 15 years. One of the more common materials being studied is CdZnTe (CZT), which can be grown using several methods to produce detector-grade materials. The work presented herein examines the effects of environmental conditions including temperature and humidity on detector performance [full-width at half-maximum (FWHM)] using the single pixel with guard detector configuration. The effects of electrical probe placement, reproducibility, and aging are also presented.     

Towards maximal heat transfer rate densities for small-scale high effectiveness parallel-plate heat exchangers

This paper addresses the question to what extent parallel-plate heat exchangers can be downsized without loss of thermal-hydraulic performance. It is shown that when the characteristic length scales of the channels are reduced at a constant pressure drop, the effectiveness exhibits a maximum due to axial heat conduction. The point of maximal effectiveness is found to correspond to a maximal thermal power density and thus to the minimal volume required for obtaining that effectiveness. Based on asymptotic relations for the effectiveness in the small and large channel limit, closed-form expressions are derived for the optimum geometric parameters that maximize power density in the limit of design effectiveness approaching unity. These relations are extended to a broader effectiveness range by means of dimensionless correction functions that are calculated numerically. The resulting expressions define optimal elemental units that can be used to construct parallel-plate counter-flow heat exchangers with the lowest possible core volume for effectiveness values between 0.53 and 1.