This research was conducted in the state of Campeche, Mexico, between 2017 and 2018. On the one hand, the sorghum yield was explored in plots with Vertisol-type soils, which were supplied with rainwater. This had the ...This research was conducted in the state of Campeche, Mexico, between 2017 and 2018. On the one hand, the sorghum yield was explored in plots with Vertisol-type soils, which were supplied with rainwater. This had the purpose of knowing the results obtained by the producers in the area. On the other hand, an experiment was established with three factors: the genetic material of sorghum, planting density and fertilization. Finally, different varieties of soybeans and sorghum hybrids were also tested in large plots, to identify those that are best adapted to crop rotation. In the farmers’ plots, the grain yield was between 4377 and 5543 kg<span style="white-space:nowrap;">∙</span>ha<sup><span style="white-space:nowrap;">−</span>1</sup>. The planting density was from 142,667 to 197,334 plants per hectare, which indicated that, for each unit that increased the planting density, the yield increased by 37.5 grams. The experiment with three factors indicated that the best planting density was 300 thousand plants per hectare, with a grain yield of 5176 kg<span style="white-space:nowrap;">∙</span>ha<sup><span style="white-space:nowrap;">−</span>1</sup>;and the best hybrids were DKS-32 and SYN5515, with grain yields of 5794 and 3791 kg<span style="white-space:nowrap;">∙</span>ha<sup><span style="white-space:nowrap;">−</span>1</sup>, respectively;likewise, the best dose of fertilizer was between 150 and 200 kg<span style="white-space:nowrap;">∙</span>ha<sup><span style="white-space:nowrap;">−</span>1</sup> of diammonium phosphate, with a grain yield of 4527 - 4562 kg<span style="white-space:nowrap;">∙</span>ha<sup><span style="white-space:nowrap;">−</span>1</sup>. In relation to crop rotation, the varieties that stood out for their yield were Huasteca 300 and Vernal, in the case of soybeans;and the hybrids DKS-32 and SYN5515, in sorghum. Soybeans suffered greatly in their early stages of development from the excessive moisture retained by the soil, while sorghum s展开更多
A survey for Infectious Hypodermal and Haematopoietic Necrosis Virus (IHHNV) and White Spot Syndrome Virus (WSSV) was performed during two catching seasons of native shrimps in the Yucatan Coast in the Gulf of Mexico....A survey for Infectious Hypodermal and Haematopoietic Necrosis Virus (IHHNV) and White Spot Syndrome Virus (WSSV) was performed during two catching seasons of native shrimps in the Yucatan Coast in the Gulf of Mexico. The mtDNA COI barcode identified two endemic species;the southern pink shrimp Penaeus notialis (Pérez Fantante, 1967) and the northern pink shrimp Penaeus brasiliensis (Latreille, 1987) (previously described as Farfantepenaeus brasiliensis). The prevalence of IHHNV was of 18.18% in 2016, and of 8.57% in 2017. All organisms tested negative for WSSV. This is the first identification of wild shrimps in the state of Yucatan Mexico by mtDNA COI barcode as well as the first identification of IHHNV in such species. The presence of IHHNV in wild shrimps populations has a potential of persisting in the coast of Yucatan with putative detrimental effect on local fisheries because once established in natural waters and hosts;such pathogens are almost impossible to eradicate.展开更多
In the present study,an analysis of the heat and mass transfer in a ventilated cavity in a warm climate zone was carried out to analyze,among others,the temperatures and percentage of relative humidity(RH).The governi...In the present study,an analysis of the heat and mass transfer in a ventilated cavity in a warm climate zone was carried out to analyze,among others,the temperatures and percentage of relative humidity(RH).The governing equations of the mathematical model were solved through the finite volume method.We used the k-εturbulence mode to find the results of the variables of interest in seven climate records on a given day.The velocity of the inlet flow of the air-H2O mixture was varied through the Reynolds number(Re)from 500 to 10000.The outdoor weather conditions considered were solar radiation,ambient temperature,and RH.It was found that at low velocities,flow recirculation was formed inside the cavity which increased the temperature and concentration of RH.For Re=5000 the flow is predominantly forced,which tends to set the values of temperature and RH as 20°C and 20%respectively.The values of the RH increase in the afternoon hours when the solar radiation decreases to the value of zero.However,the mass transfer through the values of Sh is maintained with similar values in the seven weather records.It was concluded that when air conditioning supplies air at speeds higher than 0.26 m/s at low temperatures it produces cooling with low RH,this causes discomfort,illness and/or discomfort to the users.展开更多
文摘This research was conducted in the state of Campeche, Mexico, between 2017 and 2018. On the one hand, the sorghum yield was explored in plots with Vertisol-type soils, which were supplied with rainwater. This had the purpose of knowing the results obtained by the producers in the area. On the other hand, an experiment was established with three factors: the genetic material of sorghum, planting density and fertilization. Finally, different varieties of soybeans and sorghum hybrids were also tested in large plots, to identify those that are best adapted to crop rotation. In the farmers’ plots, the grain yield was between 4377 and 5543 kg<span style="white-space:nowrap;">∙</span>ha<sup><span style="white-space:nowrap;">−</span>1</sup>. The planting density was from 142,667 to 197,334 plants per hectare, which indicated that, for each unit that increased the planting density, the yield increased by 37.5 grams. The experiment with three factors indicated that the best planting density was 300 thousand plants per hectare, with a grain yield of 5176 kg<span style="white-space:nowrap;">∙</span>ha<sup><span style="white-space:nowrap;">−</span>1</sup>;and the best hybrids were DKS-32 and SYN5515, with grain yields of 5794 and 3791 kg<span style="white-space:nowrap;">∙</span>ha<sup><span style="white-space:nowrap;">−</span>1</sup>, respectively;likewise, the best dose of fertilizer was between 150 and 200 kg<span style="white-space:nowrap;">∙</span>ha<sup><span style="white-space:nowrap;">−</span>1</sup> of diammonium phosphate, with a grain yield of 4527 - 4562 kg<span style="white-space:nowrap;">∙</span>ha<sup><span style="white-space:nowrap;">−</span>1</sup>. In relation to crop rotation, the varieties that stood out for their yield were Huasteca 300 and Vernal, in the case of soybeans;and the hybrids DKS-32 and SYN5515, in sorghum. Soybeans suffered greatly in their early stages of development from the excessive moisture retained by the soil, while sorghum s
文摘A survey for Infectious Hypodermal and Haematopoietic Necrosis Virus (IHHNV) and White Spot Syndrome Virus (WSSV) was performed during two catching seasons of native shrimps in the Yucatan Coast in the Gulf of Mexico. The mtDNA COI barcode identified two endemic species;the southern pink shrimp Penaeus notialis (Pérez Fantante, 1967) and the northern pink shrimp Penaeus brasiliensis (Latreille, 1987) (previously described as Farfantepenaeus brasiliensis). The prevalence of IHHNV was of 18.18% in 2016, and of 8.57% in 2017. All organisms tested negative for WSSV. This is the first identification of wild shrimps in the state of Yucatan Mexico by mtDNA COI barcode as well as the first identification of IHHNV in such species. The presence of IHHNV in wild shrimps populations has a potential of persisting in the coast of Yucatan with putative detrimental effect on local fisheries because once established in natural waters and hosts;such pathogens are almost impossible to eradicate.
文摘In the present study,an analysis of the heat and mass transfer in a ventilated cavity in a warm climate zone was carried out to analyze,among others,the temperatures and percentage of relative humidity(RH).The governing equations of the mathematical model were solved through the finite volume method.We used the k-εturbulence mode to find the results of the variables of interest in seven climate records on a given day.The velocity of the inlet flow of the air-H2O mixture was varied through the Reynolds number(Re)from 500 to 10000.The outdoor weather conditions considered were solar radiation,ambient temperature,and RH.It was found that at low velocities,flow recirculation was formed inside the cavity which increased the temperature and concentration of RH.For Re=5000 the flow is predominantly forced,which tends to set the values of temperature and RH as 20°C and 20%respectively.The values of the RH increase in the afternoon hours when the solar radiation decreases to the value of zero.However,the mass transfer through the values of Sh is maintained with similar values in the seven weather records.It was concluded that when air conditioning supplies air at speeds higher than 0.26 m/s at low temperatures it produces cooling with low RH,this causes discomfort,illness and/or discomfort to the users.
