Siva Ganesh

Rumen microbial community composition varies with diet and host, but a core microbiome is found across a wide geographical range.

Ruminant livestock are important sources of human food and global greenhouse gas emissions. Feed degradation and methane formation by ruminants rely on metabolic interactions between rumen microbes and affect ruminant productivity. Rumen and camelid foregut microbial community composition was determined in 742 samples from 32 animal species and 35 countries, to estimate if this was influenced by diet, host species, or geography. Similar bacteria and archaea dominated in nearly all samples, while protozoal communities were more variable. The dominant bacteria are poorly characterised, but the methanogenic archaea are better known and highly conserved across the world. This universality and limited diversity could make it possible to mitigate methane emissions by developing strategies that target the few dominant methanogens. Differences in microbial community compositions were predominantly attributable to diet, with the host being less influential. There were few strong co-occurrence patterns between microbes, suggesting that major metabolic interactions are non-selective rather than specific.

Two different bacterial community types are linked with the low-methane emission trait in sheep.

The potent greenhouse gas methane (CH4) is produced in the rumens of ruminant animals from hydrogen produced during microbial degradation of ingested feed. The natural animal-to-animal variation in the amount of CH4 emitted and the heritability of this trait offer a means for reducing CH4 emissions by selecting low-CH4 emitting animals for breeding. We demonstrate that differences in rumen microbial community structure are linked to high and low CH4 emissions in sheep. Bacterial community structures in 236 rumen samples from 118 high- and low-CH4 emitting sheep formed gradual transitions between three ruminotypes. Two of these (Q and S) were linked to significantly lower CH4 yields (14.4 and 13.6 g CH4/kg dry matter intake [DMI], respectively) than the third type (H; 15.9 g CH4/kg DMI; p<0.001). Low-CH4 ruminotype Q was associated with a significantly lower ruminal acetate to propionate ratio (3.7±0.4) than S (4.4±0.7; p<0.001) and H (4.3±0.5; p<0.001), and harbored high relative abundances of the propionate-producing Quinella ovalis. Low-CH4 ruminotype S was characterized by lactate- and succinate-producing Fibrobacter spp., Kandleria vitulina, Olsenella spp., Prevotella bryantii, and Sharpea azabuensis. High-CH4 ruminotype H had higher relative abundances of species belonging to Ruminococcus, other Ruminococcaceae, Lachnospiraceae, Catabacteriaceae, Coprococcus, other Clostridiales, Prevotella, other Bacteroidales, and Alphaproteobacteria, many of which are known to form significant amounts of hydrogen. We hypothesize that lower CH4 yields are the result of bacterial communities that ferment ingested feed to relatively less hydrogen, which results in less CH4 being formed.

Accounting Practice Harmony, Accounting Regulation and Firm Characteristics

Harmonization of accounting standards has been the subject of many initiatives taken at international, regional and national levels in recent years. Policy makers advancing this idea believe that accounting regulation harmony will lead to practice harmony. The literature in the area of accounting harmonization also generally relies on a similar belief. Comparing accounting regulations and accounting practices of two countries that are pursuing a program of harmonization, Australia and New Zealand, revealed some association between the levels of regulation harmony and practice harmony. Although this indicates that regulatory harmony can improve practice harmony, the association is ‘noisy’, suggesting that there are also other factors affecting practice harmony. Evidence adduced here shows that accounting practice harmony is also associated with firm‐specific characteristics.

Relationship between character of skin cover of coated pears and permeance to water vapour and gases

Abstract Pear fruit (Pyrus communis L.) with different skin characteristics (non-lignified: ‘Bartlett’, ‘Doyenne du Comice’ and ‘Packhams Triumph’; or with lignified cells in the skin: ‘Beurre Bosc’) were treated at harvest with a carnauba-based wax emulsion at concentrations of 0, 5, 10, 20, 40, and 100% (v/v) of the commercial formulation to achieve different coating deposits on the skin and assessed for skin permeance at 20°C and 60–70% RH. ‘Bartlett’ had the highest natural skin permeance to water vapour and gases, followed by ‘Bosc’, ‘Comice’ and ‘Packhams’. Small increases in coating deposit on the skin substantially reduced permeance to H2O (P′H2O), O2 (P′O2) and CO2 (P′CO2) in cultivars with non-lignified skin, by improving coverage of cracks in the cuticle and blockage of lenticels. These cultivars also underwent a larger reduction in P′O2 than P′CO2 with increasing coating deposits. While ‘Bartlett’ and ‘Comice’ showed a more variable reduction in P′O2 than in P′CO2 with increases in coating deposit, the inverse was observed for ‘Packhams’. ‘Bosc’, with lignified cells in the skin, had only small changes in P′H2O with waxing. In addition, P′O2 and P′CO2 decreased similarly and more gradually with increasing coating deposits in ‘Bosc’ than in the other cultivars. The epidermis of ‘Bosc’, comprising an irregular layer of lignified cells, seemed to have high P′H2O and low P′O2 and P′CO2. Improving the coating deposit on the skin blocked the lenticels, providing a more variable reduction in P′CO2 than in P′O2. However, this did not effectively cover the lignified cells in the epidermis, providing variable and small changes in P′H2O. These results show that optimisation of surface coatings for pears must take into account differences in the nature of the skin.

Determination of lower oxygen limits for apple fruit

Abstract Knowledge of the lower oxygen limit ( LOL ) is critical for optimising the gaseous storage environment for fruits. The optimum storage atmosphere occurs just above the LOL at which aerobic respiration is at the lowest level which can be achieved without development of anaerobic metabolism. Measures of LOL based on a fruits internal atmosphere, rather than external or package atmospheres, estimate the true LOL as these account more directly for differences in respiration rate and skin permeance of individual fruit. Two measures of LOL were considered: the anaerobic compensation point ( ACP ) and the fermentation threshold ( FT ). The ACP was described in terms of plots of the internal partial pressure of CO 2 versus internal O 2 ( p O 2 i ) and external O 2 ( p O 2 e ) partial pressures. The FT was described in terms of plots of both the respiratory quotient ( RQ ) and ethanol concentration versus p O 2 i and p O 2 e , and occurred at higher p O 2 than the ACP . Mathematical solutions for estimating the ACP and the FT based on the RQ ( FT RQ ) are described. A statistical ‘bootstrap’ procedure is described for estimating the FT based on ethanol concentration ( FT EtOH ) and was also suitable for estimating all other LOLs and their confidence intervals. LOL s were estimated for ‘Coxs Orange Pippin’ apples ( Malus domestica , Borkh) at 24 °C using controlled atmospheres (CA). The steady-state internal partial pressures of O 2 , CO 2 and concentrations of acetaldehyde, ethyl acetate and ethanol were estimated non-invasively by sampling the headspace of 1000 mm 3 glass surface chambers sealed to the equatorial surface of the apples. LOLs estimated on a p O 2 i basis were on average 1.69 kPa, 1.94 kPa and 2.10 kPa p O 2 lower for ACP , FT RQ and FT EtOH respectively than those estimated relative to p O 2 e . The bootstrap 95% confidence limits for internal ACP ( ACP i ) were 0.70 to 0.78 kPa p O 2 i whilst for internal FT RQ ( FT RQ ) the interval was 1.04 to 1.20 kPa p O 2 i and for internal FT EtOH ( FT EtOH ) 0.68 to 0.87 kPa P O 2 i . Bootstrap estimates were similar, though typically higher, than mathematically fitted estimates. Determining LOL s on a steady-state internal atmosphere basis estimates the true LOL more accurately than those estimated from external or package atmospheres, and provides a more mechanistic basis for models used to predict fruit responses to CA. As the FT RQ represents the critical point at which fermentation occurs it was considered the safest estimate of the true LOL for optimising storage atmospheres.

Effects of coating concentration, ripening stage, water status and fruit temperature on pear susceptibility to friction discolouration

Abstract Pear fruit ( Pyrus communis L.) cv. ‘Duyenne du Comice’ were treated at harvest with different concentrations of a carnauba-based wax emulsion and assessed for susceptibility to friction discolouration (FD) after different periods in cold storage. Susceptibility to FD was low at harvest but increased with storage, especially between 1 and 2 months storage. Concomitantly, higher coating concentrations were required to reduced FD with prolonged storage; coating concentrations of 20 and 40% were necessary to reduce FD for fruit damaged after 1 and 2 months storage, respectively. Increasing coating concentration reduced internal O 2 partial pressure and reduced water loss. The lower internal O 2 level in coated fruit was associated with delayed ripening and reduced fruit susceptibility to FD. Reduced water loss preserved the integrity of skin and reduced susceptibility to FD. Higher levels of FD were observed at temperatures lower or higher than 10–20°C. The physical protection provided by skin coatings in combination with their effects on fruit physiology, presents a useful opportunity to reduce FD after cold storage, if adopted in conjunction with adequate temperature and humidity control during storage and post-storage handling of the fruit.

Financial Distress Prediction in China

We use four alternative prediction models to examine the usefulness of financial ratios in predicting business failure in China. China has unique legislation regarding business failure so it is an interesting laboratory for such a study. Earnings Before Interest and Tax to Total Assets (EBITTA), Earning Per Share (EPS), Total Debt to Total Assets (TDTA), Price to Book (PB), and the Current Ratio (CR), are shown to be significant predictors. Prediction accuracy achieves a range from 78% to 93%. Logit and Neural Network models are shown to be the optimal prediction models.

The combined effect of delayed application of yeast biocontrol agents and fruit curing for the inhibition of the postharvest pathogen Botrytis cinerea in kiwifruit

Abstract Application of biocontrol agents (BCAs) and use of induced host resistance for the inhibition of pathogen infection have often been examined separately. The present study focused on application of yeast BCAs alone and the interaction between kiwifruit curing and BCA application for inhibition of infection by the pathogen Botrytis cinerea. Kiwifruit pedicels were removed at the natural abscission layer and the pedicel wound was used to evaluate efficacy of up to five yeast candidates, applied at increasing delay intervals after B. cinerea challenge. Other fruit were treated with combinations and various sequences of fruit curing (incubation at 10°C) and topical yeast application. All yeast candidates conferred a significant level of biocontrol following applications made simultaneously with, or up to 96 h after B. cinerea inoculation. Biocontrol activity was further increased with an additive effect of BCA and fruit curing combined but only when BCA application was made after 96 h of fruit curing. These results suggest that a degree of protection of the kiwifruit could be achieved with the application of the yeast to the pedicel wound. If kiwifruit curing is initiated, host resistance mechanisms may not be specific to the pathogen, B. cinerea, since the effect of epiphytic microbes used for biocontrol appear to be similarly reduced by factors induced in the first 24–48 h of curing.

Temperature effects on the internal lower oxygen limits of apple fruit

Abstract Exposure of packaged fresh produce in modified atmospheres (MA) to elevated temperatures can cause the partial pressure of oxygen inside the produce ( P O 2 i ) to fall below internal lower O 2 limits ( LOL i s), resulting in fermentation and loss of quality. In this study, two types of LOL i were estimated from steady-state external chamber atmospheres: the anaerobic compensation point ( ACP i ), and the fermentation threshold based on the respiratory quotient ( FT RQ i ) and on ethanol (EtOH) accumulation ( FT EtOH i ). Mean estimates of LOL i s of apple cultivars ‘Coxs Orange Pippin’ and ‘Braeburn’ ranged between 0.5 and 1.0 kPa internal partial pressure of O 2 ( p O 2 i for ACP i ; 0.8 and 1.7 kPa p O 2 i for FT RQ i , and 0.5 and 2.0 kPa p O 2 i for FT EtOH i , for fruit temperatures between 0 ° and 28 °C. Values for ACP i estimated at 32 °C were higher than those between 0 ° and 28 °C. In general, estimates of dissolved O 2 concentration at ACP i and FT RQ i tended to decrease with increasing temperature for ‘Braeburn’ apples, changed little for ‘Coxs Orange Pippin’ apples, but increased again for ACP i at 32 °C. On average, estimates of LOL i s were higher for ‘Braeburn’ than ‘Coxs Orange Pippin’ apples. The effect of temperature on diffusion coefficients and solubility were considered unlikely to contribute significantly to variation in LOL i s except for solubility at higher temperatures, but differences in tissue porosity may have influenced differences in LOL i s between cultivars. Results of the current study indicate temperature effects on LOL i s would not be significant except for MA packages destined for markets with ambient temperatures in excess of 28 °C. On the other hand it seems that to assume that ACP i is independent of temperature may be too simplistic, particularly if fruit are exposed to a very wide range of temperatures. LOL i s were relatively constant compared with lower O 2 limits based on package atmospheres, and can be used to estimate optimum MA package atmospheres that account for fruit within a population with the highest respiration rates and lowest permeance to O 2 .

Characterising ripening behaviour of coated pears in relation to fruit internal atmosphere

Abstract Pear ( Pyrus communis L.) cultivars ‘Bartlett’, ‘Beurre Bosc’, ‘Doyenne du Comice’, and ‘Packhams Triumph’ were treated at harvest or after cold storage with concentrations of 0, 5, 10, 20, 40, and 100% (v/v) of a commercial carnauba-based wax emulsion. Fruit were assessed for ripening and internal atmosphere composition at 0°C/90–95% RH (only for ‘Comice’) and at 20°C/60–70% RH (for all cultivars, after they achieved the chilling requirement to ripen). For all cultivars coated at harvest and ripening at 20°C, respiration rates, softening and colour change followed a Michaelis–Menten model when plotted against internal partial pressure of O 2 p O 2 i , while internal partial pressure of CO 2 ( p CO 2 i ) had virtually no explanatory power for these variables. This supports the notion that modification of p O 2 i rather than p CO 2 i is the principal means by which coating achieves its effects on ripening behaviour of pears during shelf life. Michaelis–Menten constant values ( K m ) for respiration and softening were lower than those for colour change for all cultivars at 20°C. This resulted in colour change being retarded by any level of depression in p O 2 i created by coating, while firmness was substantially reduced only at much lower p O 2 i during shelf life. Plots of p CO 2 i and respiration versus p O 2 i for fruit coated either pre-climacteric (at harvest) or entering the climacteric (after cold storage), indicated that ‘Comice’ and ‘Packhams’ were tolerant to hypoxia whereas, with ‘Bartlett’ and ‘Bosc’, tolerance reduced with advancing ripening, and the latter cultivar was the least tolerant of all four cultivars. During storage at 0°C of ‘Comice’, coatings had a more substantial effect in delaying softening than colour change; firmness retention seemed to be related to increase of p CO 2 i , while the limited suppression of colour change seemed to be related to small reductions of p O 2 i . Therefore, optimisation of surface coatings for pears must account for differences between cultivars and ripening stage at which fruit are coated, as well as the temperature at which the fruit are going to be held.