Predictive models to measure the impact of fiber-optic broadband speeds on local towns and communities

Internet availability and speed can impact a local community’s education, healthcare, safety, and economic development. Currently, there are few, if any, formal analyses to help communities make informed decisions on investments in internet and bandwidth expansion. This is in spite of the longstanding view posited by economic policy researchers that certain public infrastructure investments must be analyzed on a local government basis. Here, we adopt the local community focus and combine data from local, state and federal sources to develop models that predict the impacts of fiber-optic bandwidth expansion on economic factors for individual towns and communities. Our predictive analysis also demonstrates differing impacts related to town size and yields interesting outcomes related to local geographies. The rankings and comparisons derived from our predictive methodology can be used by town and state planners to holistically plan internet infrastructure development across localities. Our modeling approach can be applied to develop models specific to other towns and communities facing similar decisions regarding investments in internet speed.     

Determination of ionized magnesium in platelets and correlation with selected variables

We describe a method for determining the intracellular ionized magnesium concentration ([Mg2+]i) in platelets by using the fluorescent probe FURAPTRA. We determined the dissociation constant (KD) of FURAPTRA for Mg2+ (2.26 +/- 0.29 mmol/L), within-day assay variability (CV = 6.8%), among-day intraindividual variability (CV = 11.0%), variability after a 4-h delay in processing the blood specimen (t = 1.2, P >0.2; F = 6.2, P <0.02), and the reference interval (0.23-0.59 mmol/L) for this assay. We also evaluated the correlation between platelet [Mg2+]i and concentrations of selected serum electrolytes, proteins, and total cholesterol; age; body mass index; and gender. Only the inverse correlation between platelet [Mg2+]i and serum total cholesterol concentration in men was significant (r=-0.66, P <0.005).     

Synthesis of diamond from the carbon in the detonation products of explosives

Chelyabinsk. Translated from Fizika Goreniya i Vzryva, Vol. 26, No. 3, pp. 123–125, May–June, 1990.     

Vessel routing and scheduling under uncertainty in the liquefied natural gas business

Liquefied natural gas (LNG) is natural gas transformed into liquid state for the purpose of transportation mainly by specially built LNG vessels. This paper considers a real-life LNG ship routing and scheduling problem where a producer is responsible for transportation from production site to customers all over the world. The aim is to create routes and schedules for the vessel fleet that are more robust with respect to uncertainty such as in sailing times due to changing weather conditions. A solution method and several robustness strategies are proposed and tested on instances with time horizons of 3–12 months. The resulting solutions are evaluated using a simulation model with a recourse optimization procedure. The results show that there is a significant improvement potential by adding the proposed robustness approaches.     

Unravelling the Elusive Antiferromagnetic Order in Wurtzite and Zinc Blende CoO Polymorph Nanoparticles

Although cubic rock salt‐CoO has been extensively studied, the magnetic properties of the main nanoscale CoO polymorphs (hexagonal wurtzite and cubic zinc blende structures) are rather poorly understood. Here, a detailed magnetic and neutron diffraction study on zinc blende and wurtzite CoO nanoparticles is presented. The zinc blende‐CoO phase is antiferromagnetic with a 3rd type structure in a face‐centered cubic lattice and a Néel temperature of T_N (zinc‐blende) ≈225 K. Wurtzite‐CoO also presents an antiferromagnetic order, T_N (wurtzite) ≈109 K, although much more complex, with a 2nd type order along the c‐axis but an incommensurate order along the y‐axis. Importantly, the overall magnetic properties are overwhelmed by the uncompensated spins, which confer the system a ferromagnetic‐like behavior even at room temperature.     

Halloysite nanotubes immobilized by chitosan/tannic acid complex as a green flame retardant for bamboo fiber/poly(lactic acid) composites

In order to develop an environmentally benign flame retardant for bamboo/PLA composites (BPC), chitosan (CS) and tannic acid (TA) were used as cationic and anionic polyelectrolyte respectively to stabilize halloysite nanotubes (HNT) on the surface of bamboo fiber (BF) and poly(lactic acid) (PLA). Mechanical performance tests showed that the flexural properties of BPC were moderately enhanced with the addition of HNT, while the incorporation of CS/TA complex (FR) exhibited a slight increase. The results of thermogravimetric analysis demonstrated that CS/TA complex and HNT improved the thermal stability of the BPC synergistically, which increased the char residue. Limiting oxygen index and cone calorimetry tests were used to study the flammability of BPC and the results showed that the addition of CS/TA complex and HNT had a synergistic effect on the flame retardant performance of BPC materials. The macroscopic and microscopic morphological studies confirmed the formation of HNT layer in the matrix of BPC/5FR@5HNT samples, which facilitated more stabile char residue with the best flame retardant performance.     

Inter-residual Hydrogen Bonding in Carbohydrates Unraveled by NMR Spectroscopy and Molecular Dynamics Simulations

Carbohydrates, also known as glycans in biological systems, are omnipresent in nature where they as glycoconjugates occur as oligo- and polysaccharides linked to lipids and proteins. Their three-dimensional structure is defined by two or three torsion angles at each glycosidic linkage. In addition, transglycosidic hydrogen bonding between sugar residues may be important. Herein we investigate the presence of these inter-residue interactions by NMR spectroscopy in D₂O/[D₆]DMSO (70:30) or D₂O and by molecular dynamics (MD) simulations with explicit water as solvent for disaccharides with structural elements α-d -Manp-(1→2)-d -Manp, β-d -GlcpNAc-(1→2)-d -Manp, and α-d -Glcp-(1→4)-β-d -Glcp, all of which have been suggested to exhibit inter-residue hydrogen bonding. For the disaccharide β-d -GlcpNAc-(1→2)-β-d -Manp-OMe, the large extent of O5′ ⋅⋅⋅ HO3 hydrogen bonding as seen from the MD simulation is implicitly supported by the ¹H NMR chemical shift and ³J_HO3,H3 value of the hydroxy proton. In the case of α-d -Glcp-(1→4)-β-d -Glcp-OMe, the existence of a transglycosidic hydrogen bond O2′⋅⋅⋅HO3 was proven by the presence of a cross-peak in ¹H,¹³C HSQC-TOCSY experiments as a result of direct TOCSY transfer between HO3 of the reducing end residue and H2′ (detected at C2′) of the terminal residue. The occurrence of inter-residue hydrogen bonding, albeit transient, is judged important for the stabilization of three-dimensional structures, which may be essential in maintaining a conformational state for carbohydrate–protein interactions of glycans to take place in biologically important environments.     

A study of the ice crystals in vacuum-packed salmon fillets (Salmon salar) during superchilling process and following storage

The aim of this work was to study the microstructure of vacuum-packed salmon fillets superchilled in an impingement freezer at −30 °C (air temperature) and 227 W/m² K (surface heat transfer coefficient, SHTC) for 2.1 min prior to storage at a superchilling storage temperature of −1.7 ± 0.3 °C for 28 days. The microstructure of vacuum-packed salmon fillets were analysed at the surface, mid-centre and centre layers. Significant differences were observed between the ice crystals formed at the surface, mid-centre and centre layers. The size of ice crystals at the centre of the superchilled fillets was 3 times larger than those at the surface layer. Significant differences were observed between the size of ice crystals formed during the superchilling process and following storage. The results further indicated that, after temperature equalisation (1 day of storage) the growth of the intracellular ice crystal was not significant at (P < 0.05) at any storage time.     

Chemoenzymatic synthesis of structured triacylglycerols containing eicosapentaenoic and docosahexaenoic acids

There are indications in the recent literature that the location of polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in triacylglycerols (TAG) may influence their oxidative stability. To address that question, two types of structured lipids were designed and synthesized: firstly, a TAG molecule possessing pure EPA or DHA at the mid-position with stearic acid at the outer positions; and secondly, a TAG molecule possessing pure EPA or DHA located at one of the outer positions with stearic acid at the mid-position and the remaining end position. The former adduct was synthesized in two steps by a chemoenzymatic approach. In the first step 1,3-distearolyglycerol was afforded in good yield (74%) by esterifying glycerol with two equivalents of stearic acid in ether in the presence of silica gel using Lipozyme^TM as a biocatalyst. This was followed by a subsequent chemical esterification with pure EPA or DHA using 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide as a coupling agent in the presence of 4-dimethylaminopyridine in dichloromethane in excellent yields (94 and 91, respectively). The latter adduct was synthesized in two enzymatic steps. In the first step tristearoylglycerol was prepared in very high yield (88%) by esterifying glycerol with a stoichiometric amount of stearic acid under vacuum at 70–75°C using an immobilized Candida antarctica lipase without a solvent. That adduct was subsequently treated in an acidolysis reaction with two equivalents of EPA or DHA without solvent at 70–75°C or in toluene at 40°C in the presence of Lipozyme to afford the desired product in moderate yields (44 and 29%, respectively). This work was presented at the Biocatalysis Symposium in April 2000, held at the 91st Annual Meeting and Expo of the American Oil Chemists’ Society, San Diego, CA.     

Endosperm and whole grain rye breads are characterized by low post-prandial insulin response and a beneficial blood glucose profile

Background  

Rye products have previously been shown to induce comparatively low post-prandial insulin responses; irrespectively of their glycaemic indices (GI). However, the mechanism behind this lowered insulin demand remains unknown. An improved insulin economy might contribute to the benefits seen in epidemiological studies with whole grain diets on metabolic risk factors and weight regulation. The objective of this study was to explore the mechanism for a reduced post-prandial insulin demand with rye products.