Evaluation of ambient and chilled aeration strategies to maintain the quality of stored grain in tropical climates and during summer in temperate climates

Master of ScienceDepartment of Grain Science and IndustryCarlos Campabadal TeranThe use of grain aeration as a tool to minimize post-harvest losses requires lower ambient temperature (≤ 20°C) and relative humidity (≤ 70%) conditions than what is usually available during the summer season in temperate climates and throughout the year in some tropical climate regions. Warm and moist conditions contribute to pest problems and increase dependence on chemical control for pest reduction as part of grain management strategies. The grain chilling technology is a non-chemical alternative to cool grain stored under high risk climatic conditions. For this research project, the grain chilling technology was tested in a 1,350-ton low moisture content wheat silo during the 2015 and 2016 summer harvests in Kansas. The grain temperature was lowered from a maximum of 39°C to a minimum of 17°C in less than 250 hours. The results showed that chilled grain maintained at temperatures under 20°C reduced the development rate of insect pests compared to grain stored at temperatures over 25°C and cooled with ambient aeration. However, the cost of grain chilling was calculated to be between 0.26 and 0.32 $/t higher than using ambient aeration. Through computer simulation it was possible to evaluate the performance of the grain chiller against four different ambient aeration strategies for paddy rice stored under the tropical climatic conditions of the North Pacific coast of Costa Rica. After six months of storage, the minimum grain temperature achieved through ambient aeration was 30.8°C using an aeration strategy based on a grain-ambient temperature differential greater than 10°C. Grain chilling lowered the average grain temperature from 35°C to below 15°C in 117 hours and the maximum average temperature it registered after six months of storage was 15.5°C. The economic evaluation of the simulated ambient aeration and chilling strategy determined that the operational costs of grain chilling were between 2 and 4$/t lower than ambient aeration plus fumigation. However, the initial cost of the grain chiller made the net present cost (NPC) of the chilling strategy between 0.22 and 0.85 $/t higher than the cost of ambient aeration plus fumigation over a 10-year analysis. Several potential financial options were analyzed to make the grain chiller more economically feasible for a rice miller in Costa Rica. It was concluded that the grain chilling technology can reduce grain temperatures below 20°C in a relatively short period of time, which helps control insect populations and maintain grain quality during summer storage in temperate climates and in tropical climates. Utilizing grain chilling reduced operational costs between 78$74,700 for the grain chiller would require a 16% discount or at least 10,641 t to be chilled annually to make this technology viable for the Costa Rican rice milling industry. Leasing the grain chiller (ten equal payments of $10,926) or adding a premium sell price of 1$/t to chilled rice would make this technology feasible compared to the traditional grain management strategies utilized in Costa Rica

Chilling Aeration to Control Pests and Maintain Grain Quality during In-Bin Storage of Wheat in Kansas

Chilling aeration of stored grain is becoming very popular around the world since it offers many advantages in situations where ambient air conditions are not adequate to cool grain. It allows to cool grain, independent of ambient conditions, to “safe” temperatures where insect, fungi, and spoilage development is reduced to the minimum, and at the same time can potentially reduce chemical control use. The objective of this research was to evaluate the effectiveness of chilling aeration to preserve grain quality and control insect-pests. The research trial was developed from August to November 2015 in Central Kansas in two 1,270 metric tons (MT) steel bins with low-moisture wheat from the 2015 summer harvest. One bin was chilled and the other was used as a control (ambient aeration). Variables evaluated were: moisture content (MC), grain and flour quality, insect-pest development and reproduction rate, insect fragments per kg, and fungi presence. Chilling aeration cooled the grain in 135 hours to an average of 17⁰C, with minimum variation through the four months. Ambient aeration in the control bin cooled the grain to an average of 22⁰C after 308 hours, with variation over 16⁰C through the four months. Lower temperatures significantly diminished insect development and reproduction rate. Flour quality was better preserved in the chilled than in the control bin. There was no significant effect on MC, grain quality or fungi presence. The energy cost of running the grain chiller was 0.22 $/MT more than the cost of ambient aeration in the control bin

Chilled aeration to control pests and maintain grain quality during the summer storage of wheat in north central region of Kansas: Presentation

Chilled aeration allows to cool grain, independent of ambient conditions, to "safe" temperatures where insect, fungi, and spoilage is reduced to the minimum. The objective of this research was to evaluate the advantages of using grain chilling to preserve the quality of grain and reduce post-harvest losses, compared to conventional aeration and storage strategies used during the summer storage of wheat in Central Kansas, U.S.A. The research trials were developed in two 1,350 metric ton (t) steel silos in a Farmer’s Cooperative during the summer and fall of 2015 and 2016. One of the silos was chilled and the other was used as a control managed by the Cooperative. Variables evaluated were: grain temperature, moisture content (MC), grain quality, insect development and reproduction rate. The chilling treatment reduced the grain temperature from 28°C- 39°C to a minimum of 17°C- 17.6°C in less than 250 hours. Grain temperatures below 25°C were not possible during the summer using ambient aeration. Minimum variation of MC was observed in the Chilled silo while ambient aeration reduced the MC by 0.5%. Reproduction rates of RFB and LGB were significantly reduced by chilled temperatures lower than 17°C. Lower temperatures also reduced insects discovered in probe traps and insect damaged kernels (IDK). The energy cost of the grain chiller was between 0.26 US $/t- 0.32 US$/t higher than ambient aeration.Chilled aeration allows to cool grain, independent of ambient conditions, to "safe" temperatures where insect, fungi, and spoilage is reduced to the minimum. The objective of this research was to evaluate the advantages of using grain chilling to preserve the quality of grain and reduce post-harvest losses, compared to conventional aeration and storage strategies used during the summer storage of wheat in Central Kansas, U.S.A. The research trials were developed in two 1,350 metric ton (t) steel silos in a Farmer’s Cooperative during the summer and fall of 2015 and 2016. One of the silos was chilled and the other was used as a control managed by the Cooperative. Variables evaluated were: grain temperature, moisture content (MC), grain quality, insect development and reproduction rate. The chilling treatment reduced the grain temperature from 28°C- 39°C to a minimum of 17°C- 17.6°C in less than 250 hours. Grain temperatures below 25°C were not possible during the summer using ambient aeration. Minimum variation of MC was observed in the Chilled silo while ambient aeration reduced the MC by 0.5%. Reproduction rates of RFB and LGB were significantly reduced by chilled temperatures lower than 17°C. Lower temperatures also reduced insects discovered in probe traps and insect damaged kernels (IDK). The energy cost of the grain chiller was between 0.26 US $/t- 0.32 US$/t higher than ambient aeration

Chilled Aeration to Control Pests and Maintain Grain Quality during Summer Storage of Wheat in the North Central Region of Kansas

Chilled aeration allows grain to be cooled, independent of ambient conditions, to “safe” temperatures at which insects, fungi, and spoilage development are reduced to a minimum. The objective of this research was to evaluate the advantages of using grain chilling to preserve the quality of grain and reduce post-harvest losses caused by insects and fungi, compared to the conventional aeration and storage strategies used during summer storage in central Kansas. The research trials were developed at a farmer‘s cooperative in central Kansas in 2015 and 2016 on low-moisture wheat harvested during the summer of 2015 and 2016, respectively, and stored in two 1,350 metric ton (t) steel silos in which one was chilled and the other was used as a control managed by the cooperative. Temperature of the grain inside each silo was monitored with temperature cables. Variables evaluated were: moisture content (MC), grain and flour quality, insect-pest development and reproduction rate, insect fragments per 500 g of grain, and fungi presence. In 2015, the chilling treatment reduced the grain temperature from 28°C to 17°C in approximately 175 h, while in 2016 it took 245 h to reach about the same temperature with an initial grain temperature of 39°C. Grain temperatures below 25°C were not achieved in the control silo during the summer using ambient aeration. Minimum variation of MC was observed in the Chilled silo while ambient aeration reduced the moisture content by 0.5%. Reproduction rates of the red flour beetle and lesser grain borer were significantly reduced by chilling temperatures lower than 17°C. Lower temperatures also reduced insect populations detected in probe traps and insect damaged kernels. Insect fragments and fungi presence had no significant increase throughout the trials in either of the silos. No clear evidence of flour quality being better preserved at lower temperatures was detected. The energy cost of running the grain chiller was between 0.26-0.32 $/t higher than ambient aeration

Management of acute diverticulitis with pericolic free gas (ADIFAS). an international multicenter observational study

Background: There are no specific recommendations regarding the optimal management of this group of patients. The World Society of Emergency Surgery suggested a nonoperative strategy with antibiotic therapy, but this was a weak recommendation. This study aims to identify the optimal management of patients with acute diverticulitis (AD) presenting with pericolic free air with or without pericolic fluid. Methods: A multicenter, prospective, international study of patients diagnosed with AD and pericolic-free air with or without pericolic free fluid at a computed tomography (CT) scan between May 2020 and June 2021 was included. Patients were excluded if they had intra-abdominal distant free air, an abscess, generalized peritonitis, or less than a 1-year follow-up. The primary outcome was the rate of failure of nonoperative management within the index admission. Secondary outcomes included the rate of failure of nonoperative management within the first year and risk factors for failure. Results: A total of 810 patients were recruited across 69 European and South American centers; 744 patients (92%) were treated nonoperatively, and 66 (8%) underwent immediate surgery. Baseline characteristics were similar between groups. Hinchey II-IV on diagnostic imaging was the only independent risk factor for surgical intervention during index admission (odds ratios: 12.5, 95% CI: 2.4-64, P =0.003). Among patients treated nonoperatively, at index admission, 697 (94%) patients were discharged without any complications, 35 (4.7%) required emergency surgery, and 12 (1.6%) percutaneous drainage. Free pericolic fluid on CT scan was associated with a higher risk of failure of nonoperative management (odds ratios: 4.9, 95% CI: 1.2-19.9, P =0.023), with 88% of success compared to 96% without free fluid ( P <0.001). The rate of treatment failure with nonoperative management during the first year of follow-up was 16.5%. Conclusion: Patients with AD presenting with pericolic free gas can be successfully managed nonoperatively in the vast majority of cases. Patients with both free pericolic gas and free pericolic fluid on a CT scan are at a higher risk of failing nonoperative management and require closer observation

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Productive performance of rainbow trout (Oncorhynchus mykiss) in cage culture under different feeding strategies

Slight improvements in the feeding efficiency can be translated in an important diminution of the production costs and feed waste that would alter the water quality. With the objective of determine the optimal daily ration during the season of greater growth and study the effect of ration on the corporal condition and dispersion of weight statures under the conditions of an commercial aqua farm, the growth of 15 000 trouts under 3 treatments was evaluated during 4 weeks: feeding to satiety (J1), growth ration (J2) and maintenance ration (J3). The total length, corporal weight and corporal condition factor differed significantly with the applied treatment, resulting in all cases J1>J2>J3. The J1 group (153.9 ± 4.12 g) demonstrated the greater dispersion of weight statures, with respect to J2 (110.5 ± 2.74 g) and J3 (75.1 ± 1.94 g). An oscillating feeding behavior, with variations from 1 to 3% of a day for another one, has been observed in J1. The relation between the specific growth rate (SGR) and the daily ration (r) fit to a quadratic function, SGR=(-0.26.R2)+(2.64.R)-3.06. On the other hand, the relation between the feed conversion ratio FCA and the SGR fit to the function CA=(0.35.SGR2)-(1.83.SGR)+3.48. The optimal R was 2.9%. However, were not significant differences for global FCA between J1 (1.32 ± 0.08) and J2 (1.13. ± 0.14). Therefore, satiety feeding would be the best option during the summer when the temperature is optimal for the growth.Leves mejoras en la eficiencia alimentaria pueden traducirse en una importante disminución de los costos de producción y de desechos de alimento que alterarían la calidad del agua. Con el objetivo de determinar la ración diaria óptima durante la estación de mayor crecimiento y estudiar el efecto del tamaño de ración sobre la condición corporal (K) de la trucha arco iris bajo las condiciones de un criadero comercial, se evaluó el crecimiento de 15 000 juveniles bajo 3 tratamientos: alimentación a saciedad (J1), ración de crecimiento (J2) y una ración de mantenimiento (J3). La longitud total, el peso corporal y el K difirieron significativamente con el tratamiento aplicado, resultando en todos los casos J1>J2>J3. Al final de la experiencia, J1 alcanzó el mayor peso corporal (153.9 ± 4.12 g) respecto de J2 (110.5 ± 2.74 g) y J3 (75.1 ± 1.94 g). J1 mostró un comportamiento alimentario oscilante, arrojando variaciones de 1 a 3% de un día para otro. La relación entre la tasa de crecimiento específico (SGR) y la ración diaria (R) ajustó a la función SGR=(-0.22.R2)+(2.57.R)-3.12. Por otro lado, la relación entre el factor de conversión del alimento (FCA) y el SGR ajustó a la función FCA=2.02.SGR-0.53. Valores óptimos de FCA se observaron con raciones al 50% de saciedad o mayores. No se encontraron diferencias significativas para FCA global entre J1 (1.32 ± 0.08) y J2 (1.13. ± 0.14). Consecuentemente, alimentar a saciedad sería la mejor opción durante el verano cuando la temperatura es óptima para el crecimiento.Fil: Morales, Gabriel Alejandro. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Producción Animal. Cátedra de Sistemas de Producción Acuatica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; ArgentinaFil: Quiros, Rolando. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Producción Animal. Cátedra de Sistemas de Producción Acuatica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; Argentin

Technical and economic evaluation of ambient and chilled aeration strategies to maintain the quality of paddy rice during storage in a tropical climate: Presentation

Warm and moist conditions of some tropical climate regions make it difficult to use ambient aeration to cool stored grain, which contributes to pest problems and increases dependence on chemical control as part of grain management strategies. Grain chilling is a non-chemical alternative to cool grain stored under high risk climatic conditions. The objective of this research was to use computer simulation to evaluate the technical and economic viability of using grain chilling compared to four ambient aeration strategies developed for paddy rice stored under the tropical climatic conditions of the North Pacific coast of Costa Rica. The minimum grain temperature achieved through ambient aeration at the end of the six-month simulated storage period was 30.8°C, using an aeration strategy based on a grain-ambient temperature differential greater than 10°C. Grain chilling lowered the average grain temperature from 35°C to below 15°C in 117 hours and the maximum average temperature it registered after six months of storage was 15.5°C. The economic evaluation of the ambient aeration and chilling strategies determined that the operational costs of grain chilling were 1.83 US $/t lower than ambient aeration plus chemical control of pests. However, the initial cost of the grain chiller made the net present cost (NPC) of the grain chilling strategy 0.22 US$/t higher than the cost of ambient aeration plus chemical control over a 10-year analysis. Several potential financial options were analyzed to make the grain chiller economically feasible for a rice miller in Costa Rica.Warm and moist conditions of some tropical climate regions make it difficult to use ambient aeration to cool stored grain, which contributes to pest problems and increases dependence on chemical control as part of grain management strategies. Grain chilling is a non-chemical alternative to cool grain stored under high risk climatic conditions. The objective of this research was to use computer simulation to evaluate the technical and economic viability of using grain chilling compared to four ambient aeration strategies developed for paddy rice stored under the tropical climatic conditions of the North Pacific coast of Costa Rica. The minimum grain temperature achieved through ambient aeration at the end of the six-month simulated storage period was 30.8°C, using an aeration strategy based on a grain-ambient temperature differential greater than 10°C. Grain chilling lowered the average grain temperature from 35°C to below 15°C in 117 hours and the maximum average temperature it registered after six months of storage was 15.5°C. The economic evaluation of the ambient aeration and chilling strategies determined that the operational costs of grain chilling were 1.83 US $/t lower than ambient aeration plus chemical control of pests. However, the initial cost of the grain chiller made the net present cost (NPC) of the grain chilling strategy 0.22 US$/t higher than the cost of ambient aeration plus chemical control over a 10-year analysis. Several potential financial options were analyzed to make the grain chiller economically feasible for a rice miller in Costa Rica

Chilled Aeration to Control Pests and Maintain Grain Quality during Summer Storage of Wheat in the North Central Region of Kansas

Chilled aeration allows grain to be cooled, independent of ambient conditions, to “safe” temperatures at which insects, fungi, and spoilage development are reduced to a minimum. The objective of this research was to evaluate the advantages of using grain chilling to preserve the quality of grain and reduce post-harvest losses caused by insects and fungi, compared to the conventional aeration and storage strategies used during summer storage in central Kansas. The research trials were developed at a farmer‘s cooperative in central Kansas in 2015 and 2016 on low-moisture wheat harvested during the summer of 2015 and 2016, respectively, and stored in two 1,350 metric ton (t) steel silos in which one was chilled and the other was used as a control managed by the cooperative. Temperature of the grain inside each silo was monitored with temperature cables. Variables evaluated were: moisture content (MC), grain and flour quality, insect-pest development and reproduction rate, insect fragments per 500 g of grain, and fungi presence. In 2015, the chilling treatment reduced the grain temperature from 28°C to 17°C in approximately 175 h, while in 2016 it took 245 h to reach about the same temperature with an initial grain temperature of 39°C. Grain temperatures below 25°C were not achieved in the control silo during the summer using ambient aeration. Minimum variation of MC was observed in the Chilled silo while ambient aeration reduced the moisture content by 0.5%. Reproduction rates of the red flour beetle and lesser grain borer were significantly reduced by chilling temperatures lower than 17°C. Lower temperatures also reduced insect populations detected in probe traps and insect damaged kernels. Insect fragments and fungi presence had no significant increase throughout the trials in either of the silos. No clear evidence of flour quality being better preserved at lower temperatures was detected. The energy cost of running the grain chiller was between 0.26-0.32 $/t higher than ambient aeration.This article is published as Morales-Quiros, Alejandro, Carlos Campabadal, Dirk E. Maier, Sonia MN Lazzari, Flavio A. Lazzari, and Thomas W. Phillips. "Chilled Aeration to Control Pests and Maintain Grain Quality during Summer Storage of Wheat in the North Central Region of Kansas." Applied Engineering in Agriculture 35, no. 4 (2019): 657-688. DOI: 10.13031/aea.13252. Posted with permission.</p