Surviving in isolation: genetic variation, bottlenecks and reproductive strategies in the Canarian endemic Limonium macrophyllum (Plumbaginaceae)

Oceanic archipelagos are typically rich in endemic taxa, because they offer ideal conditions for diversification and speciation in isolation. One of the most remarkable evolutionary radiations on the Canary Islands comprises the 16 species included in Limonium subsection Nobiles, all of which are subject to diverse threats, and legally protected. Since many of them are single-island endemics limited to one or a few populations, there exists a risk that a loss of genetic variation might limit their longterm survival. In this study, we used eight newly developed microsatellite markers to characterize the levels of genetic variation and inbreeding in L. macrophyllum, a species endemic to the North-east of Tenerife that belongs to Limonium subsection Nobiles. We detected generally low levels of genetic variation over all populations (HT = 0.363), and substantial differentiation among populations (FST = 0.188;RST = 0.186) coupled with a negligible degree of inbreeding (F = 0.042). Obligate outcrossing may have maintained L. macrophyllum relatively unaffected by inbreeding despite the species’ limited dispersal ability and the genetic bottlenecks likely caused by a prolonged history of grazing. Although several factors still constitute a risk for the conservation of L. macrophyllum, the lack of inbreeding and the recent positive demographic trends observed in the populations of this species are factors that favour its future persistence

Pre-weaning traits of Brahman calves under a dual-purpose management system in the tropics

El objetivo de éste estudio fue analizar factores asociados a características del crecimiento pre-destete y debilidad neonatal (NW) en becerros puros por cruce Brahman Rojos (RB, n=86) y Blancos (GB, n=33). Los parámetros observados fueron peso al nacer (BW), y a 210-d (W210), ganancia diaria de peso a 210-d (ADG), y varias medidas lineales. Al nacer, los machos pesaron más que las hembras (31,6 ± 0,9 vs 28,5 ± 0,8 kg; P<0,002), hubo diferencias debidas al toro padre (P<0,001), y los becerros con NW tendieron a ser más livianos que los normales (29 ± 1,1 vs 31,2 ± 0,6 kg; P<0,06). A los 210-d, los machos pesaron más que las hembras (124,7 ± 3,2 vs 111 ± 3,4 kg; P<0,007) y las vacas de segundo y cuarto parto tuvieron los becerros más pesados (P<0,001). Becerros nacidos durante la época seca tuvieron mayores W210-d (122,5 ± 3,4 vs 113 ± 3,1kg; P<0,01) y ADG (0,451 ± 0,01 vs 0,388 ± 0,01 kg/d; P<0,001) que los nacidos durante la época lluviosa. Becerros hijos de vacas en su segundo y cuarto parto tuvieron mayores ADG (P<0,01). Al nacer como a los 210-d, todas las medidas lineales y el peso corporal se hallaron correlacionados (P<0,001). A los 210-d, los becerros con NW fueron más livianos (113 ± 4 vs 122 ± 2,6 kg; P<0,05) y de menor talla en todas las mediciones (P<0,001) que los normales. La ocurrencia de NW fue mayor en RB que en GB (P<0,005) y se halló asociada a 3 toros (P<0,005).344 - [email protected] objective of this study was to analyze factors associated with pre-weaning growth traits (e.g., weight and linear body measurements) and neonatal weakness in graded Red (RB, n=86) and Grey Brahman (GB, n=33) calves. Observed parameters included birth weight (BW), weight at 210-d (W210), average daily gain from birth to 210-d (ADG), and multiple linear body measurements. At birth, males were heavier (31.6 ± 0.9 kg 28.5 ± 0.8 kg; P<0.002) than females, differences due to sire (P<0.001) were observed, and calves experiencing NW tended to be lighter than normal calves (29 ± 1.1 vs 31.2 ± 0.6 kg; P<0.06). At 210-d, males were heavier than females (124.7 ± 3.2 vs 111 ± 3.4 kg; P<0.007), cows in their second and fourth parities had the heaviest (P<0.001) calves. Heavier W210 (122.5 ± 3.4 vs 113 ± 3.1kg; P<0.01) and greater ADG (0.451 + 0.01 vs 0.388 + 0.01 kg/d; P<0.001) were found in calves born during dry season compared to those born during rainy season. Calves from second and fourth parity dams had greatest (P<0.01) ADG. Both at birth and 210-d., all linear body traits and body weight were highly correlated (P<0.001). Calves experiencing NW had reduced W210 (113 ± 4 vs 122 ± 2.6 kg; P<0.05) thorax circumference, hip height and dorsal length (P<0.001) compared to normals. Occurrence of NW was greater in RB than GB (P<0.005). Three sires were found to be associated with NW (P<0.005)

Efficient improvement of energy detection technique in cognitive radio networks using K-nearest neighbour (KNN) algorithm

Abstract With the birth of the IoT era, it is evident that the existing number of devices is going to rise exponentially. Any two devices will communicate with each other using the same frequency band with limited availability. Therefore, it is of vital importance that this frequency band used for communication be used efficiently to accommodate the maximum number of devices with the available radio resources. Cognitive radio (CR) technology serves this exact purpose. The stated one is an intelligent radio that is made to automatically identify the optimal wireless channel in the available wireless spectrum at a given instant. An important functionality of CR is spectrum sensing. Energy detection is a very popular algorithm used for spectrum sensing in CR technology for efficient allocation of radio resources to the devices intended to communicate with each other. Energy detection detects the presence of a primary user (PU) signal by continuously monitoring a selected frequency bandwidth. The conventional energy detection technique is known to perform poorly in lower SNR ranges. This paper works towards the improvement of the energy detection algorithm with the help of machine learning (ML). The ML model uses the general properties of the signal as training data and classifies between a PU signal and noise at very low SNR ranges (− 25 to − 10 dB). In this research, a K-nearest neighbours (KNN) model is selected for its versatility and simplicity. Upon testing the model with an out-of-sample dataset, the KNN model produced a detection accuracy of 94.5%

A histological study of the effect of saline and povidone-iodine infusions on the equine endometrium

A study was conducted to assess the reaction of the endometrium of the mare to both saline and povidone-iodine infusions. In the control group (Group 1), uterine biopsies were taken at 0, 3, 5, 7, 10, 15, 20 and 30 days from the beginning of the experimental period. The treatment groups had intrauterine infusions of saline (Group 2) or 1% povidone iodine in saline (Group 3) on Days 0 and 2, and had endometrial biopsies taken on the same days as the control group. The concentration of inflammatory cells in the endometria of the Group-2 mares paralleled that of the Group-1 mares but was at a slightly higher level. Group-3 mares demonstrated significant increases in the numbers of inflammatory cells. An acute reaction was observed in Group-3 mares until Days 7 to 10. Thereafter, the inflammatory reaction changed in nature from an acute to a more chronic reaction. By Days 15 to 30, Group 3 still demonstrated increased signs of inflammation, including infiltration with eosinophils. The results of this study indicate that intrauterine infusion of 1% povidone-iodine solution in mares can cause chronic inflammatory changes in the endometrium. © 1992