7,547 research outputs found

    Highly-functionalised difluorinated cyclohexane polyols via the Diels–Alder reaction : regiochemical control via the phenylsulfonyl group

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    A difluorinated dienophile underwent cycloaddition reactions with a range of furans to afford cycloadducts whichcould be processed regio- and stereoselectively via episulfonium ions, generated by the reaction between their alkenyl groups and phenylsulfenyl chloride. The oxabicyclic products were oxidised to the phenylsulfonyl level and ring opened via E1CB or reductive desulfonative pathways to afford, ultimately, difluorinated cyclohexene or cyclohexane polyols

    Attractiveness is positively related to World Cup performance in male, but not female, biathletes

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    This is the author accepted manuscript. The final version is available from Oxford University Press via the DOI in this record.Whole-organism performance capacity is thought to play a key role in sexual selection,through its impacts on both intrasexual competition and intersexual mate choice. Based on data from elite sports, several studies have reported a positive association between facial attractiveness and athletic performance in humans, leading to claims that facial correlates of sporting prowess in men reveal heritable or non-heritable mate quality. However, for most of the sports studied (soccer, ice hockey, American football and cycling) it is not possible to separate individual performance from team performance. Here, using photographs of athletes who compete annually in a multi-event World Cup,we examine the relationship between facial attractiveness and individual career-best performance metrics in the biathlon, a multidisciplinary sport that combines target shooting and cross-country skiing. Unlike all previous studies, which considered only male athletes, we report relationships for both sportsmen and sportswomen. As predicted by evolutionary arguments, we found that male biathletes were judged more attractive if (unknown to the raters) they had achieved a higher peak performance (World Cup points score) in their career, whereas there was no significant relationship for female biathletes. Our findings show that elite male athletes display visible, attractive cues that reliably reflect their athletic performance

    Anisotropic random resistor networks: a model for piezoresistive response of thick-film resistors

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    A number of evidences suggests that thick-film resistors are close to a metal-insulator transition and that tunneling processes between metallic grains are the main source of resistance. We consider as a minimal model for description of transport properties in thick-film resistors a percolative resistor network, with conducting elements governed by tunneling. For both oriented and randomly oriented networks, we show that the piezoresistive response to an applied strain is model dependent when the system is far away from the percolation thresold, while in the critical region it acquires universal properties. In particular close to the metal-insulator transition, the piezoresistive anisotropy show a power law behavior. Within this region, there exists a simple and universal relation between the conductance and the piezoresistive anisotropy, which could be experimentally tested by common cantilever bar measurements of thick-film resistors.Comment: 7 pages, 2 eps figure

    Quantifying and Maximising the Benefits of Crops After Rice

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    At the time this project was conceived, rising watertables and subsequent salinisation were considered to be the major threats to the sustainability of irrigated agriculture in the rice growing areas of southern NSW. The biggest threat to sustainability at present is the reduced availability and higher cost of water as a result of the water reforms, and more recently prolonged drought. The hypothesis of this project was that growing crops immediately after rice would increase water use efficiency and profitability of rice-based cropping systems while reducing net recharge. Field experiments were conducted from 1998 to 2000 on two soil types to evaluate the effect of non-irrigated wheat after rice on watertables and net recharge. Rainfall during the wheat season was reasonably similar in all 3 years (270-318 mm) and higher than average (220 mm). Yield and biomass production of early sown (24 April) wheat were higher than yield of late wheat (29 June) (grain yield 4.7 vs 3.8 t/ha at 12% moisture). In the absence of irrigation, the soil profile remained wet in fallow areas, whereas there was considerable drying in areas planted to wheat. The drying created capacity in the soil profile to capture and use winter rainfall. There was a general increase in depth to the watertable during the first half of the season where non-irrigated wheat was grown after rice, but not in the fallow areas. However, in all situations, the watertable rose around the time of rice sowing each year due to a rise in the regional groundwater level. The lumped water balance studies suggested net discharge of about 1 ML/ha between the time of sowing and harvesting wheat after rice in each of the three years, mostly due to higher upflow due to crop water use. In the fallow, net discharge/recharge was close to zero. The CERES Wheat and SWAGMANÂź Destiny models performed very well in simulating a wide range of crop and soil water parameters, although the validation data sets were limited in that the yield range was smaller than desirable. Consistent with the field studies, yield of nonirrigated early sown wheat (median 3.8 t/ha) was usually much higher than yield of late sown wheat (median 1.8 t/ha). With one or two irrigations yields of both early and late sown wheat almost always increased, by around 1 t/ha with one irrigation at heading, and an additional 0.5 t/ha with a second irrigation during grain filling. It was only with frequent irrigation (whenever cumulative ETo-rain since the previous irrigation reached 60 mm) that yields of late sown wheat matched (or surpassed) yields of early sown wheat. However, the irrigation requirement for late wheat irrigated at ETo-rain 60 mm was almost always much higher than for early wheat with the same irrigation management (by >100 mm in most years). While irrigation increased yield, it also increased net recharge, with final watertables generally higher by 0.5 to 0.8 m for wheat after rice (wet initial soil) with irrigation at ETo-rain 60 mm compared with no irrigation. The model simulations showed that with wheat after rice, there was net discharge in almost all years, regardless of initial watertable depth (0.5-1.5 m). In comparison, net recharge occurred in 18 to 48% of years with fallow after rice, the amount of recharge increase as initial depth to the watertable increased. For non-irrigated wheat after rice, salinity of the watertable was 2 important where the watertable was shallow (0.5 m), with yield reductions in excess of 1 t/ha in most years. However for deeper watertables, there was no effect of watertable salinity for non-irrigated wheat. With irrigation, watertable salinity had no impact on yields. Growing wheat immediately after rice was financially beneficial, with an increase in Net Present Value (NPV) ranging from 31 to 126 /ha/yrdependingontherotation.Assumingthattherateofadoptionisdoubledover20yearsasaresultoftheproject,theNPVofbenefitswasestimatedtobe/ha/yr depending on the rotation. Assuming that the rate of adoption is doubled over 20 years as a result of the project, the NPV of benefits was estimated to be 5.6 million compared with costs of $1.1 million, resulting in a benefit cost ratio of 5.3

    Quantifying and Maximising the Benefits of Crops After Rice

    Get PDF
    At the time this project was conceived, rising watertables and subsequent salinisation were considered to be the major threats to the sustainability of irrigated agriculture in the rice growing areas of southern NSW. The biggest threat to sustainability at present is the reduced availability and higher cost of water as a result of the water reforms, and more recently prolonged drought. The hypothesis of this project was that growing crops immediately after rice would increase water use efficiency and profitability of rice-based cropping systems while reducing net recharge. Field experiments were conducted from 1998 to 2000 on two soil types to evaluate the effect of non-irrigated wheat after rice on watertables and net recharge. Rainfall during the wheat season was reasonably similar in all 3 years (270-318 mm) and higher than average (220 mm). Yield and biomass production of early sown (24 April) wheat were higher than yield of late wheat (29 June) (grain yield 4.7 vs 3.8 t/ha at 12% moisture). In the absence of irrigation, the soil profile remained wet in fallow areas, whereas there was considerable drying in areas planted to wheat. The drying created capacity in the soil profile to capture and use winter rainfall. There was a general increase in depth to the watertable during the first half of the season where non-irrigated wheat was grown after rice, but not in the fallow areas. However, in all situations, the watertable rose around the time of rice sowing each year due to a rise in the regional groundwater level. The lumped water balance studies suggested net discharge of about 1 ML/ha between the time of sowing and harvesting wheat after rice in each of the three years, mostly due to higher upflow due to crop water use. In the fallow, net discharge/recharge was close to zero. The CERES Wheat and SWAGMANÂź Destiny models performed very well in simulating a wide range of crop and soil water parameters, although the validation data sets were limited in that the yield range was smaller than desirable. Consistent with the field studies, yield of nonirrigated early sown wheat (median 3.8 t/ha) was usually much higher than yield of late sown wheat (median 1.8 t/ha). With one or two irrigations yields of both early and late sown wheat almost always increased, by around 1 t/ha with one irrigation at heading, and an additional 0.5 t/ha with a second irrigation during grain filling. It was only with frequent irrigation (whenever cumulative ETo-rain since the previous irrigation reached 60 mm) that yields of late sown wheat matched (or surpassed) yields of early sown wheat. However, the irrigation requirement for late wheat irrigated at ETo-rain 60 mm was almost always much higher than for early wheat with the same irrigation management (by >100 mm in most years). While irrigation increased yield, it also increased net recharge, with final watertables generally higher by 0.5 to 0.8 m for wheat after rice (wet initial soil) with irrigation at ETo-rain 60 mm compared with no irrigation. The model simulations showed that with wheat after rice, there was net discharge in almost all years, regardless of initial watertable depth (0.5-1.5 m). In comparison, net recharge occurred in 18 to 48% of years with fallow after rice, the amount of recharge increase as initial depth to the watertable increased. For non-irrigated wheat after rice, salinity of the watertable was 2 important where the watertable was shallow (0.5 m), with yield reductions in excess of 1 t/ha in most years. However for deeper watertables, there was no effect of watertable salinity for non-irrigated wheat. With irrigation, watertable salinity had no impact on yields. Growing wheat immediately after rice was financially beneficial, with an increase in Net Present Value (NPV) ranging from 31 to 126 /ha/yrdependingontherotation.Assumingthattherateofadoptionisdoubledover20yearsasaresultoftheproject,theNPVofbenefitswasestimatedtobe/ha/yr depending on the rotation. Assuming that the rate of adoption is doubled over 20 years as a result of the project, the NPV of benefits was estimated to be 5.6 million compared with costs of $1.1 million, resulting in a benefit cost ratio of 5.3

    Changes in dietary patterns and body composition within 12 months of liver transplantation

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    Background: Cardiometabolic risk factors are increasing in liver transplant recipients (LTR). Influencing dietary factors have not been assessed. The aim of this observational study was to assess changes in weight, metabolic function, dietary intake and eating behaviours in the first year after orthotopic liver transplantation (OLT). Methods: Consecutive recruitment of 17 patients (14 males) awaiting OLT at a single tertiary hospital. Dietary intake, food behaviours and anthropometry were recorded at baseline, and 6 and 12 months posttransplant. Results: By 12 months, patients had gained on average 7.3% of body weight. The prevalence of overweight or obesity increased from baseline 53% to 77% (P=0.001). By 6 months, 65% (n=11/17) of patients had altered glucose metabolism. Dietary intake was consistent with a Western-style dietary pattern with high saturated fat. Over half of the patients (69%, n=11/16) reported low to no depressive feelings and rated their self-esteem as good (53%, n=9/16). The Power of Food Scale increased between pre and post-transplant, indicating a stronger appetitive drive. Conclusions: Weight gain occurs early post-transplant, with significant metabolic dysfunction present within 6 months, however is not associated with significant psychological distress. Early dietary intervention designed to limit weight gain and target cardiometabolic health is recommended for this unique patient population

    Magnetic phase diagram of the Hubbard model

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    The competition between commensurate and incommensurate spin-density-wave phases in the infinite-dimensional single-band Hubbard model is examined with quantum Monte Carlo simulation and strong and weak coupling approximations. Quantum fluctuations modify the weak-coupling phase diagram by factors of order unity and produce remarkable agreement with the quantum Monte Carlo data, but strong-coupling theories (that map onto effective Falicov-Kimball models) display pathological behavior. The single-band model can be used to describe much of the experimental data in Cr and its dilute alloys with V and Mn.Comment: 12 pages plus 3 uuencoded postscript figures, ReVTe

    Spin and charge excitations in incommensurate spin density waves

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    Collective excitations both for spin- and charge-channels are investigated in incommensurate spin density wave (or stripe) states on two-dimensional Hubbard model. By random phase approximation, the dynamical susceptibility \chi(q,\omega) is calculated for full range of (q,\omega) with including all higher harmonics components. An intricate landscape of the spectra in \chi(q,\omega) is obtained. We discuss the anisotropy of the dispersion cones for spin wave excitations, and for the phason excitation related to the motion of the stripe line. Inelastic neutron experiments on Cr and its alloys and stripe states of underdoped cuprates are proposed

    How Are Red and Blue Quasars Different? The Radio Properties

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    A non-negligible fraction of quasars are red at optical wavelengths, indicating (in the majority of cases) that the accretion disc is obscured by a column of dust which extinguishes the shorter-wavelength blue emission. In this paper, we summarize recent work by our group, where we find fundamental differences in the radio properties of SDSS optically-selected red quasars. We also present new analyses, using a consistent color-selected quasar parent sample matched to four radio surveys (FIRST, VLA Stripe 82, VLA COSMOS 3 GHz, and LoTSS DR1) across a frequency range 144 MHz–3 GHz and four orders of magnitude in radio flux. We show that red quasars have enhanced small-scale radio emission (∌kpc) that peaks around the radio-quiet threshold (defined as the ratio of 1.4 GHz luminosity to 6 ÎŒm luminosity) across the four radio samples. Exploring the potential mechanisms behind this enhancement, we rule out star-formation and propose either small-scale synchrotron jets, frustrated jets, or dusty winds interacting with the interstellar medium; the latter two scenarios would provide a more direct connection between opacity (dust; gas) and the production of the radio emission. In our future study, using new multi-band uGMRT data, we aim to robustly distinguish between these scenarios
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