Use of molecular markers and major genes in the genetic improvement of livestock

Recent developments in molecular biology and statistics have opened the possibility of identifying and using genomic variation and major genes for the genetic improvement of livestock. Information concerning the basis of these techniques and their applications to the genetic improvement of animals is reviewed. Main marker molecular marker systems in animals (RFPL and microsatellites), genome maps, methods for detecting marker major gene linkages and use of marker assisted selection, genetic fingerprinting and mixture models based on segregation analysis are analyzed. The characteristics where the application of marker assisted selection can be more effective are those that are expressed late in the life of the animal, or controlled by a few pairs of genes. The first example correspond to the longevity and carcass characteristics in meat producing animals, the second, to the resistance to certain diseases or defects of simple inheritance. The detection of major genes using mixture models with segregation analysis can direct the work of identification of DNA marker genotypes towards populations and characteristics with greater probability of detecting a major gene using molecular markers. The present trend indicates that molecular, pedigree and phenotypic information will be integrated in the future through mixture models of segregation analysis that might contain major gene effects through the markers, polygenic inheritance and uses powerful and flexible methods of estimation such as Gibbs Sampling

Acantosis nigricans asociado a malignidad

La Acantosis nigricans se caracteriza por presentar hiperpigmentación, hiperqueratosis y presencia de papilomatosis Múltiple que afectan en forma simétrica principalmente los pliegues cutáneos. Según etiología se clasifica en dos grandes grupos: benigna y Maligna. En el presente artículo describimos el caso de una Mujer de 42 años afectada de un carcinoma pobremente diferenciado tipo difuso en estómago y paralelamente desarrollo Acantosis Nigricans. Se revisa además la fisiopatología y el posible mecanismo patogénico común de estas manifestaciones dermatológicas en relación a la neoplasia interna

Técnicas de indentación: medición de propiedades mecánicas en cerámicas

Las técnicas de indentación poseen una gran versatilidad que permite evaluar propiedades mecánicas en volúmenes inferiores a 0.001 mm3, hasta volúmenes del orden de los mm3, útil tanto en materiales compuestos como en volumen. Este artículo hace una revisión general de los fundamentos de éstas técnicas. También se muestran algunas de las dificultades que surgen cuando éstas son aplicadas a la medición de propiedades mecánicas de materiales cerámicos, tales como su dureza tenacidad a la fractura, módulo de elasticidad y adherencia de capas cerámicas en sustratos metálicos. Para esto se utilizan algunos materiales cerámicos en volumen como alúmina Al2O3, Titanato de Bario BaTiO3 y capas TiN depositadas sobre acero M2

Eight Weeks of Combined Exercise Training Induced Improvements in Insulin Sensitivity is Associated with Improvement in Aerobic Capacity, but not with Improvement in Strength.

A lifestyle compromised of predominantly sedentary behavior is a risk factor that promotes the development of metabolic syndrome. It has been demonstrated that individuals with blunted insulin sensitivity (IS) and metabolic flexibility (MF) tend to be more prone to develop the disease. An increase in physical activity is recommended in order to prevent cardiovascular disease and type 2 diabetes mellitus. PURPOSE: to determine whether healthy, sedentary, normoglycemic, Mexican American men without a family history of type 2 diabetes are able to improve IS and MF after participating in a combined (aerobic/resistance) exercise intervention. METHODS: Subjects (n=6; 21.83±0.8 years; BMI 28.92 ± 1.6 kg/m2), participated in 8 weeks of combined exercise training three times per week (35 minutes of aerobic training & 45 minutes of resistance training/session). Upper body 1 repetition maximum (1RM) was measured using the flat barbell bench press and lower body 1RM was measured using a back leg strength dynamometer. IS was assessed using the hyperinsulinemic euglycemic clamp (clamp). Insulin dose administered to each subject was set 80mU/m2/min. MF was assessed by determining change in RQ (ΔRQ) at the steady state of the clamp compared to RQ measured at baseline/resting. Participants were provided with standard diet 5 days before pre and post intervention testing in order to control for the effects of diet on insulin sensitivity. Body composition was measured using dual x-ray absorptiometry. RESULTS: IS improved significantly after the 8 weeks of combined exercise training (3.18±0.35 to 3.75±0.34 mg/kg EMBS/min, p=0.05). There was no significant improvement in MF (0.06±0.02 to 0.08±0.02 ∆RER, p=0.19). Body weight significantly increased (3.76%; 81.06±5.38 to 84.11±5.67 kg, p=0.01) with no change in fat mass and a trend to increase in fat free mas (2.8%; 55.92±2.77 to 57.5±2.38 kg, p=0.1). Upper body strength significantly increased (168.3±26.57 to 195±26.04 lb., p=0.001). Lower body strength increased (356.7±46.52 to 428.3±34.51 lb., p=0.02).VO2 max improved significantly (3.90±0.14 to 4.19±0.16 L/min, p=0.037). Improvement in IS was associated with an increase in VO2max (r=0.92, p=0.008) but not with the improvement in strength. Improvement in MF was significantly correlated with fasting glucose (r=-0.83, p=0.04), and an increase in lean mass (r=0.82, p=0.04). CONCLUSION: 8 weeks of combined exercise improves insulin sensitivity in healthy, sedentary, normoglycemic Hispanic men. Improvement in insulin sensitivity is associated with improvement in aerobic fitness but not gain in upper and lower body strength

Experimental Assessment of a Forward-Collision Warning System Fusing Deep Learning and Decentralized Radio Sensing

This paper presents the idea of an automatic forward-collision warning system based on a decentralized radio sensing (RS) approach. In this framework, a vehicle in receiving mode employs a continuous waveform (CW) transmitted by a second vehicle as a probe signal to detect oncoming vehicles and warn the driver of a potential forward collision. Such a CW can easily be incorporated as a pilot signal within the data frame of current multicarrier vehicular communication systems. Detection of oncoming vehicles is performed by a deep learning (DL) module that analyzes the features of the Doppler signature imprinted on the CW probe signal by a rapidly approaching vehicle. This decentralized CW RS approach was assessed experimentally using data collected by a series of field trials conducted in a two-lanes high-speed highway. Detection performance was evaluated for two different DL models: a long short-term memory network and a convolutional neural network. The obtained results demonstrate the feasibility of the envisioned forward-collision warning system based on the fusion of DL and decentralized CW RS

Doppler Shift Characterization of Wideband Mobile Radio Channels

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Effect of climate and insemination technique on reproductive performance of gilts and sows in a subtropical zone of Mexico

The objective of this study was to analyse the reproductive performance of hybrid (Yorkshire x Landrace) gilts/sows in relation to temperature-humidity index (THI) at artificial insemination (AI), season of AI, occurrence of estrus >8 d post-weaning, repeated estrus, insemination technique (cervical, CAI or post-cervical, PCAI) and parity. Data included 8851 reproductive records (1771 for gilts and 7080 for sows) from a pig farm in a sub-tropical zone (THI ranged from 72.9 in January to 81.8 in June). A decrease in pregnancy rate (PR, 89.8 vs 93.0%; P<0.01) and a tendency to decline farrowing rate (FR, 87.9 vs 90.3%; P=0.07) following AI during high THI (>82), compared to AI at <74 THI were observed. The spring and summer season were associated with decreased (P<0.01) PR compared with fall and winter (90.0% vs 93.0%). Likewise, FR decreased in spring and summer compared to fall and winter (88.5% vs. 90.9%). FR was higher (P<0.01) in non-repeat breeders compared with that of repeat-breeders (90.3% vs 76.2%). Litter size increased (P<0.01) from 10.8 ± 3.2 to 11.1 ± 3.1 pigs when the interval from weaning to estrus was >8 d. The insemination technique did not affect PR and FR but the litter size decreased (P<0.05) from 11.3 ± 3.0 to 11.1 ± 2.9 pigs when PCAI was used compared to CAI. This study reaffirms the negative effects of the hot season on reproductive performance of gilts/sows, although thermal stress at AI did not cause foetal losses. Also, there is no advantage in using the PCAI as compared to the CAI in gilts/sows with high numbers of sperm cells per AI