132 research outputs found
Temporal visitation patterns of points of interest in cities on a planetary scale: a network science and machine learning approach
We aim to study the temporal patterns of activity in points of interest of
cities around the world. In order to do so, we use the data provided by the
online location-based social network Foursquare, where users make check-ins
that indicate points of interest in the city. The data set comprises more than
90 million check-ins in 632 cities of 87 countries in 5 continents. We analyzed
more than 11 million points of interest including all sorts of places:
airports, restaurants, parks, hospitals, and many others. With this
information, we obtained spatial and temporal patterns of activities for each
city. We quantify similarities and differences of these patterns for all the
cities involved and construct a network connecting pairs of cities. The links
of this network indicate the similarity of temporal visitation patterns of
points of interest between cities and is quantified with the Kullback-Leibler
divergence between two distributions. Then, we obtained the community structure
of this network and the geographic distribution of these communities worldwide.
For comparison, we also use a Machine Learning algorithm - unsupervised
agglomerative clustering - to obtain clusters or communities of cities with
similar patterns. The main result is that both approaches give the same
classification of five communities belonging to five different continents
worldwide. This suggests that temporal patterns of activity can be universal,
with some geographical, historical, and cultural variations, on a planetary
scale.Comment: 18 pages, 7 figure
Condition monitoring system for characterization of electric motor ball bearings with distributed fault using fuzzy inference tools
The present work shows a condition monitoring
system applied to electric motors ball bearings. Unlike most of the previous work on this area, which is mainly focused on the
location of single-point defects in bearing components – inner and outer races, cage or ball faults -, this research covers wide
range irregularities which are very often more difficult to analyse. In addition to traditional techniques like vibration and
current signals, high frequency current bearing pulses and acoustic emissions are also analysed. High frequency bearings
current pulses are acquired using motors especially modified. This modification isolates ball bearings from the motor stator
frame, except for a bearing housing single point connected to ground through a proper cable where the pulses signal is measured. A multivariable fuzzy inference analysis approach is presented to get around the diagnosis difficulty.Peer ReviewedPostprint (published version
Factores que influyen en la duración de la vida reproductiva útil en rebaños bovinos de la provincia de Camagüey, Cuba
218 cows from five different races or crosses were sampled to characterize female bovine reproductive span. Animals were dis- tributed into seven herds out of three livestock centers in Camagüey province. Interval from reproduction cycle beginning to pregnancy by insemination to reproductive span (period between the beginning and the end of the reproduction cycle) was esti- mated. The analysis was carried out through a general lineal pattern, which showed lower values for total number of deliveries, age at the end of the reproduction cycle, interval from reproduction cycle beginning to pregnancy, and age at first calving. Aver- age reproductive span was too short (6,50 ± 0,26 years) due to cattle herd (P<0,05), race or cross (P<0,001), age at the beginning of the reproduction cycle (P<0,001), total number of deliveries (P<0,001), and age at first calving (P<0,001). Holstein x Zebu crossbreeding improved reproductive span compared to purebred cattle and ¾ Zebu x ¼ Charolaise crossing. According to these results, herd handling must be improved and genotype for each place must be properly selected to make possible a decrease in age at the beginning of the reproduction cycle and at first calving, and therefore an increase in the total number of calvings.Con el objetivo de contribuir a caracterizar la duración de la vida reproductiva de la hembra bovina y sus implicaciones, fueron seleccionadas 218 vacas de 5 razas o cruces distribuidas en 7 rebaños pertenecientes a 3 empresas pecuarias de la provincia de Camagüey. Se calcularon el intervalo entre la incorporación a la reproducción y la inseminación fecundante (intervalo incorpora- ción-gestación) y la vida reproductiva útil (perÃodo comprendido entre la incorporación a la reproducción y el desecho). Se utilizó el modelo general lineal (G.M.L.) que reflejó valores deficientes para el total de partos, la edad de desecho, el intervalo incorpora- ción-gestación y la edad al primer parto. La vida reproductiva promedio de la muestra fue sumamente corta (6,50 ± 0,26 años) y estuvo influida por el rebaño (P<0,05), la raza o cruce (P<0,001), la edad a la incorporación (P<0,001), el total de partos (P<0,001) y la edad al primer parto (P<0,001). El mestizaje del ganado Holstein con el Cebú mejoró la duración de la vida reproductiva al compararlo con las razas puras y el cruce ¾ Cebú x ¼ Charolaise. De acuerdo con los resultados obtenidos se requiere mejorar el manejo en los rebaños, lo que conjugado con la selección del genotipo adecuado a cada lugar pudiera permitir la reducción de las edades a la incorporación y al primer parto e incrementar el total de partos
Fluctuación poblacional de ototylomys phyllotis merriam, 1901 (rodentia: muridae) en una selva mediana subcaducifolia del Sur de Yucatán, México
Population dinamics of the big-eared climbing rat (Ototylomys phyllotis) was studied in a subdeciduous tropical rainforest located at Rancho Hobonil, Tzucacab, Yucatan using a mark-recapturetechnique, from April 1996 to April 1998 during five nights per 24 months. The minimum-numberknown-alive technique (MNKA) was used to estimate population size. We captured 123 rats, 52% werefemales and 48% males. The sex ratio was 1:1 during this study. Density ranged from 10 to 46 ind./ha. And was not significantly correlated with precipitation (p>0.05). Presence of reproductive individuals from both sexes during the majorities of the studied months and the reproductive activity from females suggest a continuous poliestric pattern for this species.Se estudió la dinámica poblacional de la rata arborÃcola Ototylomys phyllotis en la selva mediana subcaducifolia del Rancho Hobonil, Tzucacab, Yucatán. Se trabajó de abril de 1996 a abril de 1998, usando el método de captura recaptura y trampeando por cinco noches consecutivas cada mes. La densidad se estimó mediante el método de Número MÃnimo de Individuos Vivos (NMIV). Se capturaron un total de 123 individuos, de los cuales el 49% fueron hembras y el 51% machos. La proporción de sexos se mantuvo 1:1. La densidad poblacional fluctuó entre 10 y 46 individuos/ha. No se presentó correlación significativa entre la densidad y la precipitación pluvial anual (p<0.05). Los adultosconstituyeron el principal componente de la población. La presencia de reproductores de ambos sexos, asà como la actividad reproductiva de las hembras durante la mayorÃa de los meses de estudio, sugiereque esta especie presenta un patrón reproductivo poliéstrico continuo
Molecular Evolution in Nonrecombining Regions of the Drosophila melanogaster Genome
We study the evolutionary effects of reduced recombination on the Drosophila melanogaster genome, analyzing more than 200 new genes that lack crossing-over and employing a novel orthology search among species of the melanogaster subgroup. These genes are located in the heterochromatin of chromosomes other than the dot (fourth) chromosome. Noncrossover regions of the genome all exhibited an elevated level of evolutionary divergence from D. yakuba at nonsynonymous sites, lower codon usage bias, lower GC content in coding and noncoding regions, and longer introns. Levels of gene expression are similar for genes in regions with and without crossing-over, which rules out the possibility that the reduced level of adaptation that we detect is caused by relaxed selection due to lower levels of gene expression in the heterochromatin. The patterns observed are consistent with a reduction in the efficacy of selection in all regions of the genome of D. melanogaster that lack crossing-over, as a result of the effects of enhanced Hill–Robertson interference. However, we also detected differences among nonrecombining locations: The X chromosome seems to exhibit the weakest effects, whereas the fourth chromosome and the heterochromatic genes on the autosomes located most proximal to the centromere showed the largest effects. However, signatures of selection on both nonsynonymous mutations and on codon usage persist in all heterochromatic regions
Extra-uterine (abdominal) full term foetus in a 15-day pregnant rabbit
[EN] Background: While ectopic pregnancies account for 1-2% of all pregnancies, abdominal pregnancy is extremely rare, accounting for approximately 1% of ectopic pregnancies. Extrauterine abdominal pregnancy is defined as the implantation and development of an embryo in the peritoneal cavity. The present report is the first of an incidental case of abdominal pregnancy within four full-term foetus simultaneously with 2 weeks of physiological gestation in a healthy doe rabbit.
Case presentation: The doe was born on November 3, 2014 and the first partum took place on May 18, 2015. The doe had previously delivered and weaned an average of 12.0 +/- 1.41 live kits at birth (no stillbirths were recorded) during 5 consecutive pregnancies. The last mating was on December 18, 2015 and the detection of pregnancy failure post breeding (by abdominal palpation) on December 31, 2015. Then, the doe was artificially inseminated on January 27, 2016, diagnosed pregnant on February 11, 2016 and subsequently euthanized to recover the foetus. A ventral midline incision revealed a reproductive tract with 12 implantation sites with 15 days old foetus and 4 term foetus in abdominal cavity. There were two foetus floating on either side of the abdominal cavity and two suspended near the greater curvature of the stomach. They were attached to internal organs by means of one or 2 thread-like blood vessels that linked them to the abdominal surfaces.
Conclusions: In our opinion a systematic monitoring of rabbit breeding should be included to fully understand and enhance current knowledge of this phenomenon of abdominal pregnancy.This work was supported by Spanish Research Project AGL2014-53405-C2-1-P (Interministerial Commission on Science and Technology).Marco-Jiménez, F.; Garcia-Dominguez, X.; Valdes-Hernández, J.; Vicente Antón, JS. (2017). Extra-uterine (abdominal) full term foetus in a 15-day pregnant rabbit. BMC Veterinary Research. 13:1-4. https://doi.org/10.1186/s12917-017-1229-7S1413Petracci M, Bianchi M, Cavani C. Development of rabbit meat products fortified with n-3 polyunsaturated fatty acids. Nutrients. 2009;1:111–8.FAOSTAT (Food and Agriculture Organization of the United Nations, authors). Available online: http://faostat.fao.org/site/569/DesktopDefault.aspx?PageID=569#ancor . Accessed Sept 2012.Segura Gil P, Peris Palau B, MartÃnez MartÃnez J, Ortega Porcel J, Corpa Arenas JM. Abdominal pregnancies in farm rabbits. Theriogenology. 2004;62:642–51.Rosell JM, de la Fuente LF. Culling and mortality in breeding rabbits. Prev Vet Med. 2009;88:120–7.Tena-Betancourt E, Tena-Betancourt CA, Zúniga-Muñoz AM, Hernández-GodÃnez B, Ibáñez-Contreras A, Graullera-Rivera V. Multiple extrauterine pregnancy with early and near full-term mummified foetuses in a New Zealand white rabbit (Oryctolagus Cuniculus). J Am Assoc Lab Anim Sci. 2014;53:204–7.Sánchez JP, Theilgaard P, MÃnguez C, Baselga M. Constitution and evaluation of a long-lived productive rabbit line. J Anim Sci. 2008;86:515–25.Savietto D, Friggens NC, Pascual JJ. Reproductive robustness differs between generalist and specialist maternal rabbit lines: the role of acquisition and allocation of resources. Genet Sel Evol. 2015;47:2.Viudes-de-Castro MP, Vicente JS. Effect of sperm count on the fertility and prolificity rates of meat rabbits. Anim Reprod Sci. 1997;46:313–9.Marco-Jiménez F, Garcia-Dominguez X, Jimenez-Trigos E, Vera-Donoso CD, Vicente JS. Vitrification of kidney precursors as a new source for organ transplantation. Cryobiology. 2015;70:278–82.Garcia-Dominguez X, Vera-Donoso CD, Jimenez-Trigos E, Vicente JS, Marco-Jimenez. First steps towards organ banks: vitrification of renal primordial. Cryo Letters. 2016;37:47–52.Arvidsson A. Extra-uterine pregnancy in a rabbit. Vet Rec. 1998;142:176.GliÅ¡ić A, Radunović N, Atanacković J. Methotrexate and fallopian tubes in ectopic pregnancy. Acta veterinaria. 2006;56:375–82.Nwobodo EI. Abdominal pregnancy. A case report. Ann Afr Med. 2004;3:195–6.Nassali MN, Benti TM, Bandani-Ntsabele M, Musinguzi E. A case report of an asymptomatic late term abdominal pregnancy with a live birth at 41 weeks of gestation. BMC Res Notes. 2016;9:31.Baffoe P, Fofie C, Gandau BN. Term abdominal pregnancy with healthy new-born: a case report. Ghana Med J. 2011;45:81–3.Eleje GU, Adewae O, Osuagwu IK, Obianika CE. Post-date extra-uterine abdominal pregnancy in a rhesus negative Nullipara with successful outcome: a case report. J Women's Health. 2013;6:2.Hong CC, Armstrong ML. Ectopic pregnancy in 2 guinea-pigs. Lab Anim. 1978;12:243–4.Peters LJ. Abdominal pregnancy in a golden hamster (Mesocricetus Auratus). Lab Anim Sci. 1982;32:392–3.Xiccato G, Trocino A, Boiti C, Brecchia G. Reproductive rhythm and litter weaning age as they affect rabbit doe performance and body energy balance. Anim Sci. 2005;81:289–96.Fortun-Lamothe L, De Rochambeau H, Lebas F, Tudela F. Influence of the number of suckling young on reproductive performance in intensively reared rabbits does. In: Blasco A, editor. Proceedings of the 7th world rabbit congress; 2002. p. 125–32
One Is Enough: In Vivo Effective Population Size Is Dose-Dependent for a Plant RNA Virus
Effective population size (Ne) determines the strength of genetic drift and the frequency of co-infection by multiple genotypes, making it a key factor in viral evolution. Experimental estimates of Ne for different plant viruses have, however, rendered diverging results. The independent action hypothesis (IAH) states that each virion has a probability of infection, and that virions act independent of one another during the infection process. A corollary of IAH is that Ne must be dose dependent. A test of IAH for a plant virus has not been reported yet. Here we perform a test of an IAH infection model using a plant RNA virus, Tobacco etch virus (TEV) variants carrying GFP or mCherry fluorescent markers, in Nicotiana tabacum and Capsicum annuum plants. The number of primary infection foci increased linearly with dose, and was similar to a Poisson distribution. At high doses, primary infection foci containing both genotypes were found at a low frequency (<2%). The probability that a genotype that infected the inoculated leaf would systemically infect that plant was near 1, although in a few rare cases genotypes could be trapped in the inoculated leaf by being physically surrounded by the other genotype. The frequency of mixed-genotype infection could be predicted from the mean number of primary infection foci using the independent-action model. Independent action appears to hold for TEV, and Ne is therefore dose-dependent for this plant RNA virus. The mean number of virions causing systemic infection can be very small, and approaches 1 at low doses. Dose-dependency in TEV suggests that comparison of Ne estimates for different viruses are not very meaningful unless dose effects are taken into consideration
Traditional knowledge of wild edible plants used in the northwest of the Iberian Peninsula (Spain and Portugal): a comparative study
<p>Abstract</p> <p>Background</p> <p>We compare traditional knowledge and use of wild edible plants in six rural regions of the northwest of the Iberian Peninsula as follows: Campoo, Picos de Europa, Piloña, Sanabria and Caurel in Spain and Parque Natural de Montesinho in Portugal.</p> <p>Methods</p> <p>Data on the use of 97 species were collected through informed consent semi-structured interviews with local informants. A semi-quantitative approach was used to document the relative importance of each species and to indicate differences in selection criteria for consuming wild food species in the regions studied.</p> <p>Results and discussion</p> <p>The most significant species include many wild berries and nuts (e.g. <it>Castanea sativa, Rubus ulmifolius, Fragaria vesca</it>) and the most popular species in each food-category (e.g. fruits or herbs used to prepare liqueurs such as <it>Prunus spinosa</it>, vegetables such as <it>Rumex acetosa</it>, condiments such as <it>Origanum vulgare</it>, or plants used to prepare herbal teas such as <it>Chamaemelum nobile</it>). The most important species in the study area as a whole are consumed at five or all six of the survey sites.</p> <p>Conclusion</p> <p>Social, economic and cultural factors, such as poor communications, fads and direct contact with nature in everyday life should be taken into account in determining why some wild foods and traditional vegetables have been consumed, but others not. They may be even more important than biological factors such as richness and abundance of wild edible flora. Although most are no longer consumed, demand is growing for those regarded as local specialties that reflect regional identity.</p
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