Molecular detection and sensitivity to antibiotics and bacteriocins of pathogens isolated from bovine mastitis in family dairy herds of central Mexico.

Thirty-two farms (n = 535 cows) located in the state of Guanajuato, Mexico, were sampled. Pathogens from bovine subclinical mastitis (SCM) and clinical mastitis (CLM) were identified by 16S rDNA and the sensitivity to both antibiotics and bacteriocins of Bacillus thuringiensis was tested. Forty-six milk samples were selected for their positive California Mastitis Test (CMT) (≥3) and any abnormality in the udder or milk. The frequency of SCM and CLM was 39.1% and 9.3%, respectively. Averages for test day milk yield (MY), lactation number (LN), herd size (HS), and number of days in milk (DM) were 20.6 kg, 2.8 lactations, 16.7 animals, and 164.1 days, respectively. MY was dependent on dairy herd (DH), LN, HS, and DM (P < 0.01), and correlations between udder quarters from the CMT were around 0.49 (P < 0.01). Coagulase-negative staphylococci were mainly identified, as well as Staphylococcus aureus, Streptococcus uberis, Brevibacterium stationis, B. conglomeratum, and Staphylococcus agnetis. Bacterial isolates were resistant to penicillin, clindamycin, ampicillin, and cefotaxime. Bacteriocins synthesized by Bacillus thuringiensis inhibited the growth of multiantibiotic resistance bacteria such as S. agnetis, S. equorum, Streptococcus uberis, Brevibacterium stationis, and Brachybacterium conglomeratum, but they were not active against S. sciuri, a microorganism that showed an 84% resistance to antibiotics tested in this study.

Comparison on different insects' wing displacements using high speed digital holographic interferometry.

In-flight insect wing motion behavior depends on a wide variety of conditions. They have a complex structural system and what seems to be a rather complicated motion. Researchers in many fields have endeavoured to study and reproduce these wing movements with the aim to apply the gained knowledge in their fields and for the benefit of avionic technological improvements and insect migration studies, among many other themes. The study of in-flight insect wing motion and its measurement is a relevant issue to understand and reproduce its functionality. Being capable of measuring the wing flapping using optical noninvasive methods adds scientific and technological value to the fundamental research in the area. Four different types of butterflies found widely in Mexico's forests are used to compare their wing flapping mechanisms. An out-of-plane digital holographic interferometry system is used to detect and measure its wingmicro deformations. Displacement changes from in vivo flapping wings are registered with a CMOS high speed camera yielding full field of view images depicting these insects' wing motion. The results have a resolution in the scale of hundreds of nanometers over the entire wing surface.

Insect wing deformation measurements using high speed digital holographic interferometry.

An out-of-plane digital holographic interferometry system is used to detect and measure insect's wing micro deformations. The in-vivo phenomenon of the flapping is registered using a high power cw laser and a high speed camera. A series of digital holograms with the deformation encoded are obtained. Full field deformation maps are presented for an eastern tiger swallowtail butterfly (Pterourus multicaudata). Results show no uniform or symmetrical deformations between wings. These deformations are in the order of hundreds of nanometers over the entire surface. Out-of-plane deformation maps are presented using the unwrapped phase maps.