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1.
Insects ; 13(10)2022 Sep 25.
Article in English | MEDLINE | ID: mdl-36292819

ABSTRACT

The sterile insect technique (SIT) application, as an alternative tool for conventional mosquito control methods, has recently gained prominence. Nevertheless, some SIT components require further development, such as protocols under large-scale conditions, focusing on packing and shipping mosquitoes, and considering transporting time. Immobilization of Aedes aegypti males was tested at temperatures 4, 7, 10, and 14 °C, and each temperature was assessed for 60, 90, and 120 min. The recovery after 24 h was also studied. Chilled and control-reared males had comparable survival rates for all conditions, although 4 °C for 120 min impacted male survival. The male escape rate was affected after 60 min of exposure at 4 °C; this difference was not significant, with 24 h of recovery. First, we defined the successful immobilization at 4 °C for 60 min, thus enabling the evaluation of two transportation intervals: 6 and 24 h, with the assessment of different compaction densities of 100 and 150 mosquitoes/cm3 at 10 °C to optimize the shipment. Compaction during simulated mosquito shipments reduced survival rates significantly after 6 and 24 h. In the mating propensity and insemination experiments, the sterile males managed to inseminate 40 to 66% for all treatments in laboratory conditions. The male insemination propensity was affected only by the highest compaction condition concerning the control. The analysis of the densities (100 and 150 males/cm3) showed that a higher density combined with an extended shipment period (24 h) negatively impacted the percentage of inseminated females. The results are very helpful in developing and improving the SIT packing and shipment protocols. Further studies are required to evaluate all combined parameters' synergetic effects that can combine irradiation to assess sexual competitiveness when sterile males are released into the field.

3.
Plants (Basel) ; 6(3)2017 Sep 15.
Article in English | MEDLINE | ID: mdl-28914770

ABSTRACT

The effects of 2 mM silicon (Si) and 10 mM KNO3 (N)-prime signals for plant resistance to pathogens-were analyzed in healthy and Cowpea chlorotic mottle virus (CCMV) or Cowpea mild mottle virus (CMMV)-infected Bradyrhizobium-nodulated cowpea, yardlong bean and mung bean plants. In healthy plants of the three Vigna taxa, nodulation and growth were promoted in the order of Si + N > N > Si > controls. In the case of healthy cowpea and yardlong bean, the addition of Si and N decreased ureide and α-amino acids (AA) contents in the nodules and leaves in the order of Si + N> N > Si > controls. On the other hand, the addition of N arrested the deleterious effects of CCMV or CMMV infections on growth and nodulation in the three Vigna taxa. However, the addition of Si or Si + N hindered growth and nodulation in the CCMV- or CMMV-infected cowpea and yardlong bean, causing a massive accumulation of ureides in the leaves and nodules. Nevertheless, the AA content in leaves and nodules of CCMV- or CMMV-infected cowpea and yardlong bean was promoted by Si but reduced to minimum by Si + N. These results contrasted to the counteracting effects of Si or Si + N in the CCMV- and CMMV-infected mung bean via enhanced growth, nodulation and levels of ureide and AA in the leaves and nodules. Together, these observations suggest the fertilization with Si + N exclusively in virus-free cowpea and yardlong bean crops. However, Si + N fertilization must be encouraged in virus-endangered mung bean crops to enhance growth, nodulation and N-metabolism. It is noteworthy to see the enhanced nodulation of the three Vigna taxa in the presence of 10 mM KNO3.

4.
Viruses ; 4(12): 3804-11, 2012 Dec 14.
Article in English | MEDLINE | ID: mdl-23242372

ABSTRACT

Yardlong bean (Vigna unguiculata subsp. sesquipedalis) plants with virus-like systemic mottling and leaf distortion were observed in both experimental and commercial fields in Aragua State, Venezuela. Symptomatic leaves were shown to contain carlavirus-like particles. RT-PCR analysis with carlavirus-specific primers was positive in all tested samples. Nucleotide sequences of the obtained amplicons showed 84%-74% similarity to corresponding sequences of Cowpea mild mottle virus (CPMMV) isolates deposited in the GenBank database. This is the first report of CPMMV in Venezuela and is thought to be the first report of CPMMV infecting yardlong bean.


Subject(s)
Carlavirus/classification , Carlavirus/isolation & purification , Fabaceae/virology , Plant Diseases/virology , Carlavirus/genetics , Cluster Analysis , Molecular Sequence Data , Phylogeny , Plant Leaves/virology , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, DNA , Sequence Homology, Nucleic Acid , Venezuela
5.
Rev Invest Clin ; 63(4): 399-406, 2011.
Article in Spanish | MEDLINE | ID: mdl-22364040

ABSTRACT

INTRODUCTION: Animal models have been developed for the study of the intimal hyperplasia, a common cause of venous graft stenosis. OBJECTIVE: To establish a venous graft animal model for the study of the morphologic adaptative response to the arterial circulation. MATERIAL AND METHODS: A venous graft was placed in the arterial circulation of the caudal extremity from Wistar rats. In order to develop the model, it was carried out a morphologic study of the caudal extremity blood vessels. Three possible sites were evaluated for the obtaining of the venous graft. RESULTS: Graft permeability and viability were observed only in one segment, between the muscular branches and the origin of the saphenous vein. The portion of vein that was obtained from one extremity, was placed in the arterial circulation of the opposite extremity. CONCLUSIONS: A venous graft animal model was established, using a femoral vein segment, between the muscular branches and the origin of the saphenous vein, placing it in the homonyme artery of the opposite extremity.


Subject(s)
Blood Vessel Prosthesis Implantation/methods , Microsurgery/methods , Models, Animal , Veins/surgery , Animals , Femoral Artery/pathology , Femoral Artery/surgery , Femoral Vein/transplantation , Graft Occlusion, Vascular/etiology , Hindlimb/blood supply , Hyperplasia , Rats , Rats, Wistar , Saphenous Vein/surgery , Tunica Intima/pathology , Vascular Patency
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