Measurement of anisotropies of the kinetic energy and anharmonicity in pyrolytic graphite by neutron Compton scattering

Neutron Compton scattering (NCS) measurements of the anisotropy of the momentum distribution and the mean Laplacian of the interatomic potential ∇2V have been performed using electron volt neutrons, with wave vector transfers between 24 Å−1 and 98 Å−1. The measured momentum distribution of the atoms displays significantly more anisotropy than a calculation using a model density of states. We have observed anisotropies in ∇2V for the first time. The results suggest that the atomic potential is harmonic within the graphite planes, but anharmonic for vibrations perpendicular to the planes.

Standardising corneal nerve fibre length for nerve tortuosity increases its association with measures of diabetic neuropathy

AIMS: Recent studies on corneal markers have advocated corneal nerve fibre length as the most important measure of diabetic peripheral neuropathy. The aim of this study was to determine if standardizing corneal nerve fibre length for tortuosity increases its association with other measures of diabetic peripheral neuropathy. METHODS: Two hundred and thirty-one individuals with diabetes with either predominantly mild or absent neuropathic changes and 61 control subjects underwent evaluation of diabetic neuropathy symptom score, neuropathy disability score, testing with 10-g monofilament, quantitative sensory testing (warm, cold, vibration detection) and nerve conduction studies. Corneal nerve fibre length and corneal nerve fibre tortuosity were measured using corneal confocal microscopy. A tortuosity-standardised corneal nerve fibre length variable was generated by dividing corneal nerve fibre length by corneal nerve fibre tortuosity. Differences in corneal nerve morphology between individuals with and without diabetic peripheral neuropathy and control subjects were determined and associations were estimated between corneal morphology and established tests of, and risk factors for, diabetic peripheral neuropathy. RESULTS: The tortuosity-standardised corneal nerve fibre length variable was better than corneal nerve fibre length in demonstrating differences between individuals with diabetes, with and without neuropathy (tortuosity-standardised corneal nerve fibre length variable: 70.5 ± 27.3 vs. 84.9 ± 28.7, P < 0.001, receiver operating characteristic area under the curve = 0.67; corneal nerve fibre length: 15.9 ± 6.9 vs. 18.4 ± 6.2 mm/mm(2) , P = 0.004, receiver operating characteristic area under the curve = 0.64). Furthermore, the tortuosity-standardised corneal nerve fibre length variable demonstrated a significant difference between the control subjects and individuals with diabetes, without neuropathy, while corneal nerve fibre length did not (tortuosity-standardised corneal nerve fibre length variable: 94.3 ± 27.1 vs. 84.9 ± 28.7, P = 0.028; corneal nerve fibre length: 20.1 ± 6.3 vs. 18.4 ± 6.2 mm/mm(2) , P = 0.084). Correlations between corneal nerve fibre length and established measures of neuropathy and risk factors for neuropathy were higher when a correction was made for the nerve tortuosity. CONCLUSIONS: Standardizing corneal nerve fibre length for tortuosity enhances the ability to differentiate individuals with diabetes, with and without neuropathy.

Characterization of a DC-driven microplasma between a capillary tube and water surface

A microplasma generated between a stainless-steel capillary and water surface in ambient air with flowing argon as working gas appears as a bright spot at the tube orifice and expands to form a larger footprint on the water surface, and the dimensions of the bell-shaped microplasma are all below 1 mm. The electron density of the microplasma is estimated to be ranging from 5.32 × 109 cm−3 to 2.02 × 1014 cm−3 for the different operating conditions, which is desirable for generating abundant amounts of reactive species. A computational technique is adopted to fit the experimental emission from the N2 second positive system with simulation results. It is concluded that the vibrational temperature (more than 2000 K) is more than twice the gas temperature (more than 800 K), which indicates the non-equilibrium state of the microplasma. Both temperatures showed dependence on the discharge parameters (i.e., gas flow and discharge current). Such a plasma device could be arranged in arrays for applications utilizing plasmainduced liquid chemistry.

Measurement and Interpretation of Salinity Tolerance in Four Perennial Grasses

Whilst the topic of soil salinity has received a substantive research effort over the years, the accurate measurement and interpretation of salinity tolerance data remain problematic. The tolerance of four perennial grass species (non-halophytes) to sodium chloride (NaCl) dominated salinity was determined in a free-flowing sand culture system. Although the salinity tolerance of non-halophytes is often represented by the threshold salinity model (bent-stick model), none of the species in the current study displayed any observable salinity threshold. Further, the observed yield decrease was not linear as suggested by the model. On re-examination of earlier datasets, we conclude that the threshold salinity model does not adequately describe the physiological processes limiting growth of non-halophytes in saline soils. Therefore, the use of the threshold salinity model is not recommended for non-halophytes, but rather, a model which more accurately reflects the physiological response observed in these saline soils, such as an exponential regression curve.

Using automated supplementation systems to meet growth targets for grazing sheep

Remote drafting technology now available for sheep allows targeted supplementation of individuals within a grazing flock. This paper reports results of three experiments. Experiment 1 examined the weight change of Merino wethers allowed access to either lupin grain or whole cottonseed 0, 1, 2 or 7 days/week for 6 weeks. Experiment 2 examined the weight change of Merino wethers allowed access to either lupins or a sorghum + cottonseed meal (CSM) supplement 0, 2, 4 or 7 days/week for 8 weeks. Experiment 3 investigated the relationship between five allocations of trough space at the supplement self-feeders (5–50 cm/sheep) and the weight change of Merino wethers allowed access to lupins 1 day/week for 8 weeks. In all experiments, the Merino wethers had free access as a single group to drinking water and low quality hay in a large group pen and were allowed access to supplement once per day on their scheduled days of access. No water was available in the areas containing supplement, but one-way flow gates allowed animals to return to the group pen in their own time. There was a linear response in growth rate to increased frequency of access to lupins in Experiments 1 and 2, with each additional day of access increasing liveweight gain by 26 and 21 g/day, respectively. Similarly, the response to the sorghum + CSM supplement was linear, although significantly lower (P < 0.05), at 12 g/day. Providing access to whole cottonseed resulted in no significant change in growth rate compared with the control animals. In Experiment 3, decreasing trough space from 50 to 5 cm/sheep had no effect on sheep liveweight change. It was concluded that the relationships developed here, for growth response to increased frequency of access to lupins or a sorghum + CSM supplement, could be used to indicate the most appropriate frequency of access to supplement, through a remote drafting unit, to achieve sheep weight change targets. Also, that a trough space of 5 cm/sheep appears adequate in this supplementation system.

Resistance to the root-lesion nematode Pratylenchus thornei in wheat landraces and cultivars from the West Asia and North Africa (WANA) region.

Resistance to the root-lesion nematode Pratylenchus thornei was sought in wheat from the West Asia and North Africa (WANA) region in the Watkins Collection (148 bread and 139 durum wheat accessions) and the McIntosh Collection (59 bread and 43 durum wheat accessions). It was considered that landraces from this region, encompassing the centres of origin of wheat and where P. thornei also occurs, could be valuable sources of resistance for use in wheat breeding. Resistance was determined by number of P. thornei/kg soil after the growth of the plants in replicated glasshouse experiments. On average, durum accessions produced significantly lower numbers of P. thornei than bread wheat accessions in both the Watkins and McIntosh Collections. Selected accessions with low P. thornei numbers were re-tested and 13 bread wheat and 10 durum accessions were identified with nematode numbers not significantly different from GS50a, a partially resistant bread wheat line used as a reference standard. These resistant accessions, which originated in Iran, Iraq, Syria, Egypt, Sudan, Morocco, and Tunisia, represent a resource of resistance genes in the primary wheat gene pool, which could be used in Australian wheat breeding programs to reduce the economic loss from P. thornei.

Polypharmacy among inpatients aged 70 years or older in Australia

Objectives To investigate medication changes for older patients admitted to hospital and to explore associations between patient characteristics and polypharmacy. Design Prospective cohort study. Participants and setting Patients aged 70 years or older admitted to general medical units of 11 acute care hospitals in two Australian states between July 2005 and May 2010. All patients were assessed using the interRAI assessment system for acute care. Main outcome measures Measures of physical, cognitive and psychosocial functioning; and number of regular prescribed medications categorised into three groups: non-polypharmacy (0–4 drugs), polypharmacy (5–9 drugs) and hyperpolypharmacy (≥ 10 drugs). Results Of 1220 patients who were recruited for the study, medication records at admission were available for 1216. Mean age was 81.3 years (SD, 6.8 years), and 659 patients (54.2%) were women. For the 1187 patients with complete medication records on admission and discharge, there was a small but statistically significant increase in mean number of regular medications per day between admission and discharge (7.1 v 7.6), while the prevalence of medications such as statins (459 [38.7%] v 457 [38.5%] patients), opioid analgesics (155 [13.1%] v 166 [14.0%] patients), antipsychotics (59 [5.0%] v 65 [5.5%] patients) and benzodiazepines (122 [10.3%] v 135 [11.4%] patients) did not change significantly. Being in a higher polypharmacy category was significantly associated with increase in comorbidities (odds ratio [OR], 1.27; 95% CI, 1.20–1.34), presence of pain (OR, 1.31; 1.05–1.64), dyspnoea (OR, 1.64; 1.30–2.07) and dependence in terms of instrumental activities of daily living (OR, 1.70; 1.20–2.41). Hyperpolypharmacy was observed in 290/1216 patients (23.8%) at admission and 336/1187 patients (28.3%) on discharge, and the proportion of preventive medication in the hyperpolypharmacy category at both points in time remained high (1209/3371 [35.9%] at admission v 1508/4117 [36.6%] at discharge). Conclusions Polypharmacy is common among older people admitted to general medical units of Australian hospitals, with no clinically meaningful change to the number or classification (symptom control, prevention or both) of drugs made by treating physicians.

The UPAL process: a direct method of preparing cast aluminium alloy-graphite particle composites

A direct method of preparing cast aluminium alloy-graphite particle composites using uncoated graphite particles is reported. The method consists of introducing and dispersing uncoated but suitably pretreated graphite particles in aluminium alloy melts, and casting the resulting composite melts in suitable permanent moulds. The optical pretreatment required for the dispersion of the uncoated graphite particles in aluminium alloy melts consists of heating the graphite particles to 400° C in air for 1 h just prior to their dispersion in the melts. The effects of alloying elements such as Si, Cu and Mg on the dispersability of pretreated graphite in molten aluminium have also been reported. It was found that additions of about 0.5% Mg or 5% Si significantly improve the dispersability of graphite particles in aluminium alloy melts as indicated by the high recoveries of graphite in the castings of these composites. It was also possible to disperse upto 3% graphite in LM 13 alloy melts and retain the graphite particles in a well distributed fashion in the castings using the pre-heat-treated graphite particles. The observations in this study have been related to the information presently available on wetting between graphite and molten aluminium in the presence of different elements and our own thermogravimetric analysis studies on graphite particles. Physical and mechanical properties of LM 13-3% graphite composite made using pre-heat-treated graphite powder, were found to be adequate for many applications, including pistons which have been successfully used in internal combustion engines.

A Fair Contract for Managing Water Scarcity

In public utilities, under supply constraints, fairness considerations lead to a market failure. This paper characterizes a two-period principal-agent contract for demand management, that mitigates this market failure in urban water systems. The contract is designed as an extensive form mechanism using subgame perfect Nash equilibrium (SPNE) as the solution concept. The contract is fair; and is shown to be economically efficient if, in case of deviation by the agent, the gain to the agent and the loss to the principal are small. It is shown that the assumption can be avoided in an infinite horizon contract.

Synthesis of Isoquinolines from Indanones-Total Synthesis of Illudinine

Schmidt reaction of 5-methoxy or 7-methoxyindan-1-ones or their derivatives results exclusively in isocarbostyrils which are converted into 6-methoxy or 8-methoxyisoquinolines in good yields. This strategy has been extended to the total synthesis of illudinine methyl ester (1b) starting from methyl 8-methoxy-2,2-dimethyl-7-oxo-1,2,3,5,6,7-hexahydro-s-indacene-4-carboxylate (4).

Interactions of L-serine at the active site of serine hydroxymethyltransferases: induction of thermal stability

Serine hydroxymethyltransferase (SHMT), EC 2.1.2.1, exhibits broad substrate and reaction specificity. In addition to cleaving many 3-hydroxyamino acids to glycine and an aldehyde, the enzyme also catalyzed the decarboxylation, transamination and racemization of several substrate analogues of amino acids. To elucidate the mechanism of interaction of substrates, especially L-serine with the enzyme, a comparative study of interaction of L-serine with the enzyme from sheep liver and Escherichia coli, was carried out. The heat stability of both the enzymes was enhanced in the presence of serine, although to different extents. Thermal denaturation monitored by spectral changes indicated an alteration in the apparent T, of sheep liver and E. coli SHMTs from 55 +/- 1 degrees C to 72 +/- 3 degrees C at 40 mM serine and from 67 +/- 1 degrees C to 72 +/- 1 degrees C at 20 mM serine, respectively. Using stopped flow spectrophotometry k values of (49 +/- 5)(.)10(-3) s(-1) and (69 +/- 7).10(-3) s(-1) for sheep liver and E. coli enzymes were determined at 50 mM serine. The binding of serine monitored by intrinsic fluorescence and sedimentation velocity measurements indicated that there was no generalized change in the structure of both proteins. However, visible CD measurements indicated a change in the asymmetric environment of pyridoxal 5'-phosphate at the active site upon binding of serine to both the enzymes. The formation of an external aldimine was accompanied by a change in the secondary structure of the enzymes monitored by far UV-CD spectra. Titration microcalorimetric studies in the presence of serine (8 mM) also demonstrated a single class of binding and the conformational changes accompanying the binding of serine to the enzyme resulted in a more compact structure leading to increased thermal stability of the enzyme.

Conversion between electromagnetically induced transparency and absorption in a three-level lambda system

We show that it is possible to change from a subnatural electromagnetically induced transparency (EIT) feature to a subnatural electromagnetically induced absorption (EIA) feature in a (degenerate) three-level. system. The change is effected by turning on a second control beam counter-propagating with respect to the first beam. We observe this change in the D-2 line of Rb in a room temperature vapor cell. The observations are supported by density-matrix analysis of the complete sublevel structure including the effect of Doppler averaging, but can be understood qualitatively as arising due to the formation of N-type systems with the two control beams. Since many of the applications of EIT and EIA rely on the anomalous dispersion near the resonances, this introduces a new ability to control the sign of the dispersion. Copyright (C) EPLA, 2012

Quantum heat engines: A thermodynamic analysis of power and efficiency

We show that the operation and the output power of a quantum heat engine that converts incoherent thermal energy into coherent cavity photons can be optimized by manipulating quantum coherences. The gain or loss in the efficiency at maximum power depends on the details of the output power optimization. Quantum effects tend to enhance the output power and the efficiency as the photon occupation in the cavity is decreased.

Electrical properties of buckled multiwalled carbon nanotube arrays in the diffusive regime

We report the geometrical effect of graded buckled multiwalled carbon nanotube arrays on the electrical transport properties in the diffusive regime, via successive breakdown caused by the Joule heating. This breakdown occurs in the straighter region. Empirical relations involving the current-carrying ability, resistance, breakdown power, threshold voltage, diameter and length of carbon nanotube arrays are discussed on the basis of an extensive set of experimental data along with justification. The experimental results are corroborated by the density functional tight-binding calculations of electronic band structure. The band gap decreases as buckleness increases leading to the enhancement in the current-carrying ability and elucidating the role of buckleness in carbon nanotubes. Copyright (c) EPLA, 2012