Consumption of solutions containing sodium chloride is enhanced in female oxytocin-deficient mice.

Intact and ovariectomized oxytocin (OT)-deficient (OT-/-) and wild-type (OT+/+) mice were tested for consumption of 0.5 M NaCl solution or tap water in a 2-bottle choice test. During 3 days of acclimation, voluntary ingestion of NaCl was equal between genotypes. After overnight fluid deprivation, intact OT-/- mice ingested 2 times more NaCl solution than OT+/+ mice in the 6th hr, but not the 1 st hr, after reintroduction of fluid. Ovariectomized mice consumed less than intact mice after overnight fluid deprivation. When a 0.2 M NaCl solution was administered for 6 days in ovariectomized mice, OT-/- mice voluntarily consumed greater amounts than OT+/+ mice. After overnight fluid deprivation, consumption by OT-/- mice was 3 times that of OT+/+ mice at 1 hr and 2-fold greater after 6 hr. Enhanced intake of NaCl-containing solutions in female OT-/- mice suggests that central OT may be an important inhibitor of sodium consumption. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of hydraulic excavator Human–Machine Interface concepts using NASA TLX

This study evaluated newly proposed Human–Machine Interface (HMI) design concepts for improving the ergonomics of hydraulic excavators. The design concepts were based on an augmented interaction technique which involved the use of heads-up display (HUD) and coordinated control as HMI elements. Two alternative HMI designs were elaborated in order to separately evaluate the ergonomic impacts of the head-up display and the coordinated control by comparing them to the standard HMI design. The effectiveness of these three HMI designs in terms of the reduction of the operators' mental and physical workload were assessed by conducting experiments utilizing human subjects, ages 23–35 years. The National Aeronautics and Space Administration's Task Load Index (NASA TLX) method was used for collecting subjective workload scores based on a weighted average of ratings of six factors: Mental Demand, Physical Demand, Temporal Demand, Own Performance, Effort, and Frustration Level. The results showed that the type of HMI design affects different aspects of the operator's workload. Indeed, it showed how the proposed augmented interaction is an effective solution for reducing the ergonomic gaps in terms of mental workload, and to a lesser extent the physical workload, subjected by the standard HMI design.     

Enhancing thermal and dynamic-mechanical properties of epoxy reinforced by amino-functionalized microcrystalline cellulose

In this study, microcrystalline cellulose (MCC) was chemically modified with 3-(aminopropyl)triethoxysilane and added to epoxy to improve chemical, thermal and dynamic-mechanical characteristics of the composites. The composites were manufactured aided by sonication with 1.0%, 2.5%, or 5.0% wt/wt of untreated MCC or amino-functionalized MCC (MCC-Si). The epoxy/MCC-Si composites showed a decrease in the ─OH band by Fourier-transform infrared spectroscopy, and X-ray diffraction analysis indicated better dispersion. The incorporation of MCC-Si in epoxy resin decreased the heat of reaction, increased activation energy values (E_a) and pre-exponential factor (A), and did not affect thermal degradation. All conversion degree (α) versus temperature curves for the composites showed a sigmoidal shape. MCC-Si composites showed better dynamic-mechanical properties than the MCC counterparts, and the functionalization effect was evidenced in storage modulus (E') and loss modulus (E"). At 2.5% wt/wt of MCC-Si content an increase of 119% in E' at the glassy region, 127% in E' at the rubbery region and 173% in E" was observed compared to the neat resin, whereas the T_g barely changed among samples. Good adhesion between the amino-functionalized MCC and the epoxy matrix was observed at the fracture surface, evidencing that surface modification of MCC improves their chemical interaction.     

Aramid pulp treated with imidazolium ionic liquids as a filler in rigid polyurethane bio-foams

This article reports an aramid pulp (AP) treated with two ionic liquids (IL), namely 1-n-butyl-3-methylimidazolium chloride (C₄.Cl) and 1-carboxymethyl-3-methylimidazolium chloride (HO₂C), and its use as a filler in reinforced rigid polyurethane foams (RPUF). The RPUF were incorporated with the treated AP at three weight fractions (c.a. 0.1, 0.5, and 1.0 wt%) and were produced by the free rising method. The results showed that the studied IL promoted a better interaction between the AP and the RPUF system, which increased the overall reactivity, imparting a higher cell anisotropy. This also yielded a positive effect in mechanical properties and thermal stability of the RPUF. Compared to the neat RPUF, outstanding increases of approximately 50 and 20% were achieved in compressive modulus and strength, respectively. In all, the use of IL promoted increased compatibility between matrix and reinforcement, especially that HO₂C IL.     

Discrete Time Non-Homogeneous Semi-Markov Reliability Transition Credit Risk Models and the Default Distribution Functions

This paper shows how to apply discrete time non-homogeneous semi-Markov processes (DTNHSMP) with an age index to credit risk. The idea is to consider the credit risk problem as a reliability model indexed by the age and in this way, many semi-Markov results could be adapted to describe credit risk problem. The default state is seen as a “non working state”. As the semi-Markov process is a generalization of Markov process, the presented model can be seen as a more general migration model. In fact, in semi-Markov environment the distribution function (d.f.) of the waiting time before a transition can be of any type and without the strong constraints of the Markov model. Furthermore, some results on the asymptotic behavior of the presented model are given. This permits the construction of the d.f. of the default random variable for each “working state”. An example, constructed manipulating some Standard & Poor’s (S&P) data, is presented.     

Electronic nose and GC–MS analysis of volatile compounds in Tuber magnatum Pico: Evaluation of different storage conditions

The characteristic aromatic composition of white truffles (Tuber magnatum Pico) determines its culinary and commercial value. However modifications of truffle organoleptic proprieties occur during preservation. A study of headspace of white truffles by using Electronic nose (E-nose), gas chromatography–mass spectrometry (GC–MS) and sensory analyses was performed. Truffles were stored at different conditions for 7 days: +4 and +8 °C wrapped in blotting paper or covered by rice or none of the above. Headspace E-nose measurements and sensory analyses were performed each day. Statistical multivariate analysis of the data showed the capability of E-nose to predict sensorial analysis scores and to monitor aroma profile changes during storage. Truffle’s volatile molecules were also extracted by headspace solid phase microextraction technique and separated and identified by GC–MS. Partial Components Analysis of data was performed. E-nose and GC–MS results were in agreement and showed that truffle storage in paper at +8 °C seemed to be the best storage condition.     

Investigation of cure kinetics in epoxy/multiwalled carbon nanotube nanocomposites

With the increased interest in thermoset resin nanocomposites, it is important to understand the effects of the material on nanoscale characteristics. In this study, a curing reaction of an epoxy resin, which contained 0.25, 0.50, or 1.00 wt % of multiwalled carbon nanotubes (MWCNTs), at different heating rates was monitored by differential scanning calorimetry; cure kinetics were also evaluated to establish a relationship between crosslinking (network formation) and mechanical properties. MWCNT concentrations above 0.25 wt % favored crosslinking formation and decreased the activation energy (E_a) in the curing reaction. Examination of the kinetic mechanism suggests that the MWCNT locally restricted the spatial volume and favored the formation of nodular morphology in the resin, especially for high MWCNT concentrations. The MWCNT exhibited some entanglement in the matrix, which hindered a more pronounced effect on the mechanical properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39857.     

Potent,Metabolically Stable 2‐Alkyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐adenines as Adenosine A2A Receptor Ligands

Inhibition of adenosine A_2A receptors has been shown to elicit a therapeutic response in preclinical animal models of Parkinson’s disease (PD). We previously identified the triazolo‐9H‐purine, ST1535, as a potent A_2AR antagonist. Studies revealed that ST1535 is extensively hydroxylated at the ω‐1 position of the butyl side chain. Here, we describe the synthesis and evaluation of derivatives in which the ω‐1 position has been substituted (F, Me, OH) in order to block metabolism. The stability of the compounds was evaluated in human liver microsomes (HLM), and the affinity for A_2AR was determined. Two compounds, (2‐(3,3‐dimethylbutyl)‐9‐methyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐purin‐6‐amine ( 3 b ) and 4‐(6‐amino‐9‐methyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐purin‐2‐yl)‐2‐methylbutan‐2‐ol ( 3 c ), exhibited good affinity against A_2AR (K_i=0.4 nM and 2 nM , respectively) and high in vitro metabolic stability (89.5 % and 95.3 % recovery, respectively, after incubation with HLM for two hours).