Production of Massless Fermions during Inflation

We compute the one loop self energy, in a locally de Sitter background, for a massless fermion which is Yukawa-coupled to a massless, minimally coupled scalar. We then solve the modified Dirac equation resulting from inclusion of the self energy. We find faster-than-exponential growth in the fermion wave function, consistent with the production of fermions through a process in which a scalar and a fermion-anti-fermion pair are ripped out of the vacuum by inflation.Comment: 17 pages, LaTeX 2e, 1 figure. The first 15 pages gives the text of version 1, which matches the published version. The erratum appended on page 15 corrects a crucial sign error which COMPLETELY CHANGES THE PHYSICAL CONCLUSION

Postoperative complications after pancreatoduodenectomy for malignancy: results from the Recurrence After Whipple’s (RAW) study

Background Pancreatoduodenectomy (PD) is associated with significant postoperative morbidity. Surgeons should have a sound understanding of the potential complications for consenting and benchmarking purposes. Furthermore, preoperative identification of high-risk patients can guide patient selection and potentially allow for targeted prehabilitation and/or individualized treatment regimens. Using a large multicentre cohort, this study aimed to calculate the incidence of all PD complications and identify risk factors. Method Data were extracted from the Recurrence After Whipple’s (RAW) study, a retrospective cohort study of PD outcomes (29 centres from 8 countries, 2012–2015). The incidence and severity of all complications was recorded and potential risk factors for morbidity, major morbidity (Clavien–Dindo grade > IIIa), postoperative pancreatic fistula (POPF), post-pancreatectomy haemorrhage (PPH) and 90-day mortality were investigated. Results Among the 1348 included patients, overall morbidity, major morbidity, POPF, PPH and perioperative death affected 53 per cent (n = 720), 17 per cent (n = 228), 8 per cent (n = 108), 6 per cent (n = 84) and 4 per cent (n = 53), respectively. Following multivariable tests, a high BMI (P = 0.007), an ASA grade > II (P II patients were at increased risk of major morbidity (P < 0.0001), and a raised BMI correlated with a greater risk of POPF (P = 0.001). Conclusion In this multicentre study of PD outcomes, an ASA grade > II was a risk factor for major morbidity and a high BMI was a risk factor for POPF. Patients who are preoperatively identified to be high risk may benefit from targeted prehabilitation or individualized treatment regimens

Effect of method of secondary fermentation and type of base wine on physico-chemical and sensory qualities of sparkling plum wine

Plum base wines prepared with potassium metabisulphite or sodium benzoate were converted into sparkling wine, either by `Methode Champenoise' or tank method with artificially carbonated wine serving as a control. In both the secondary fermentation methods ethanol and low temperature acclimatized yeast; Saccharomyces cerevisiae UCD-595 with optimized sugar (1.5%) and di-ammonium hydrogen phosphate (0.2%) were used. Both methods of sparkling wine production and the type of base wine affected the physico-chemical and sensory characteristics of the sparkling wine produced. In the secondary fermented wines, most of the physico-chemical characteristics were altered compared to that of artificially carbonated wines except volatile acidity, methanol, propanol and ethanol. Furthermore, these wines contained lower proteins, minerals and amyl alcohol than the base wine. In general, the sparkling wines produced by either of the secondary fermentation method had lower sugar, more alcohol, higher macro elements but lower Fe and Cu contents than the artificially carbonated wines. An overview of the changes occurring in the sparkling wine in comparison to artificially carbonated wine revealed that most of the changes took place due to secondary fermentation. The bottle fermented wine recorded the highest pressure, low TSS and sugars. The secondary bottle fermented wine was the best in most of the sensory qualities but needed proper acid-sugar blend of the base wine before conducting secondary fermentation. Sparkling wine made from base wine with sodium benzoate was preferred to that prepared with potassium metabisulphite. The studies showed the potential of plum fruits for production of sparkling wine.<br>Os vinhos a base de ameixa preparado com metabisulfito de potássio ou benzoato de sódio foram convertidos em vinhos espumantes pelo método "Champenoise" ou método de tanque, usando vinho carbonatado artificialmente como controle. Em ambos métodos a fermentação secundária do ethanol a baixa temperatura aclimatizou a levedura Saccharomyces cerevisiae UCD-595 utilizando 1.5% de açúcar e 0.2% de fosfato di-amônio de hidrogênio. Não foi verificado nenhum tipo de alteração físico-química ou sensorial em nenhum dos métodos utilizados para a produção do vinho espumante Foram verificadas alterações físico-químicas na fermentação secundária do vinho espumante quando comparado com o vinho carbonatado artificialmente, exceto acidez volátil, metanol, propanol e ethanol. Além do mais, estes vinhos contiveram concentrações inferiores de proteínas, minerais e álcool amílico que o vinho de base. Em geral, os vinhos espumantes produzidos por qualquer método de fermentação secundária apresentaram açúcar residual baixo, concentrações elevadas de álcool, macroelementos elevados e concentrações baixas de Fe e Cu nos vinhos carbonatados artificialmente. Uma visão geral das mudanças que ocorrem no vinho espumante em comparação ao vinho carbonatado artificialmente demonstrou que a maioria das mudanças ocorreu devido a fermentação secundária. A garrafa do vinho fermentado registrou pressão elevada, TSS e açúcares residuais reduzidos. O Vinho espumante produzido utilizando benzoato de sódio foi preferido em relação ao preparado com metabissulfito de potássio. Esses estudos demostraram o potencial do uso de frutas como ameixa na produção de vinho espumante

Tunable diffusive lateral inhibition in chemical cells

The Belousov-Zhabotinsky (BZ) reaction has become the prototype of nonlinear chemical dynamics. Microfluidic techniques provide a convenient method for emulsifying BZ solutions into monodispersed drops with diameters of tens to hundreds of microns, providing a unique system in which reaction-diffusion theory can be quantitatively tested. In this work, we investigate monolayers of microfluidically generated BZ drops confined in close-packed two-dimensional (2D) arrays through experiments and finite element simulations. We describe the transition from oscillatory to stationary chemical states with increasing coupling strength, controlled by independently varying the reaction chemistry within a drop and diffusive flux between drops. For stationary drops, we studied how the ratio of stationary oxidized to stationary reduced drops varies with coupling strength. In addition, using simulation, we quantified the chemical heterogeneity sufficient to induce mixed stationary and oscillatory patterns