164 research outputs found
A utilização de sémen fresco na fertilização in vitro de embriões ovinos melhora a qualidade dos blastocistos na raça portuguesa Merino
A produção de embriões em ovinos é uma tarefa difícil, exigindo experiência e condições onerosas, principalmente na
produção de embriões in vivo. A recolha sistemática de oócitos em animais de matadouro ou em animais vivos por ovum
pick-up, permite a produção in vitro de embriões (IVP), em larga escala e menos dispendiosa, nos pequenos ruminantes.
Esta possibilidade é importante não só como fonte de embriões mas também de oócitos e zigotos para fins comerciais ou de
investigação, facilitando a sua disponibilidade em tecnologias emergentes tais como a clonagem ou a transgénese. Para IVP
foram desenvolvidos vários protocolos de maturação, utilizando fertilização in vitro (IVF) com sémen fresco ou congelado.
Em Portugal, a produção de embriões in vitro foi somente realizada com sémen congelado dada a sua disponibilidade em
condições de rotina. Contudo, o sémen fresco poderá melhorar a produção de embriões frescos ou criopreservados.
Este trabalho teve como objectivo comparar a eficiência da IVP em ovinos usando diferentes protocolos de maturação de
oócitos e IVF com sémen fresco ou congelado. Oócitos (n=1768) recolhidos em matadouro foram maturados em meio
TCM199 com 100 μM cisteamine, 10 ng mL-1 EGF, 10 μg mL-1 E2 e gentamicina (mat A, n=692) ou suplementada com
10 μg mL-1 FSH e 0,3 mM piruvato de sódio (mat B, n=707) a 39 ºC e 5% CO2 durante 22h. O sémen fresco (FS) e
congelado/descongelado (TS) de carneiros de raça Merino Branco (n=3) foi lavado ou submetido a swim-up,
respectivamente. Após a fertilização (18h p.i.), os presumíveis zigotos foram cultivados em meio de fluido sintético do
oviducto (SOF) enriquecido com aminoácidos e BSA a 38,5 ºC, em atmosfera humidificada com 5% O2, 5% CO2 e 90% N2
até ao estadio de 2-4-8 células. Após clivagem, o desenvolvimento embrionário prosseguiu até ao estadio de blastocisto em
meio SOF, BSA e 10% FCS. A qualidade foi avaliada no dia 6-7, classificando-se como bons, médios e maus, baseado nos
parâmetros IETS. Os dados das taxas de produção embrionária foram analisados utilizando ANOVA. Foi utilizado o teste
de Mann-Whitney U para avaliação da qualidade dos embriões.
Os diferentes protocolos de maturação não interferiram (p>0,05) quer com as taxas de maturação quer com as taxas de
produção de embriões. A qualidade embrionária foi superior (p=0,004) na fertilização com sémen fresco (bom:
FS=40,1±8,0% vs TS=32,9±5,6%; média: FS=20,1±4,7% vs TS=35,7±5,8%; má: FS=39,8±9,8% vs TS=31,4±7,6%).
Em conclusão, estes resultados preliminares mostram que o sémen fresco de carneiro pode ser facilmente utilizado
para fertilização in vitro e melhora a qualidade dos embriões produzidos.#Embryo production in sheep is a difficult task demanding experience and expensive facilities, particularly when dealing
with in vivo embryo production. Easy ways to obtain ovine embryos consist of collecting oocytes at slaughterhouses or
systematically pick them up from live animals, allowing a large scale and cheaper in vitro embryo production (IVP) for
small ruminants. Those are important sources of embryos, oocytes and zygotes for commercial, laboratorial and research
proposes, making easier the availability of resources for emerging techniques like cloning or transgenesis. For IVP, several
oocyte maturation protocols have been developed using fertilization (IVF) either with fresh or frozen-thawed semen. In
Portugal, IVP has been done through IVF using cryopreserved semen because it is easily available for routine use.
However, the use of fresh semen could improve embryo production and cryopreservation results.
The aim of this work was to compare the efficiency of in vitro embryo production in ovine using different oocyte
maturation protocols and fresh or frozen semen for IVF.
Abattoir-derived oocytes (n=1768) were matured in TCM199, 10 μM cysteamine, 10 ng mL-1 EGF, 10 μg mL-1 E2 and
gentamicin (mat A, n=692) or plus 10 μg mL-1 FSH and 0.3 mM sodium piruvate (mat B, n=707) at 39 ºC and 5% CO2 for
22h. Prior to fertilization, either fresh (FS) or frozen/thawed (TS) semen from Merino rams (n=3) was washed or submitted
to swim-up respectively. Presumptive zygotes (18h p.i.) were cultured in synthetic oviductal fluid (SOF) enriched with
aminoacids and 6 mg mL-1 BSA at 38.5 ºC, under 5% O2, 5% CO2 and 90% N2 in an humidified atmosphere until the stage
of 2-4-8 cell embryos. After assessing cleavage, embryo development proceeded until the blastocyst stage in SOF+BSA and
10% FCS. Quality was evaluated on D6-7 by scoring embryos as good, fair and bad based on IETS guidelines. Data from
embryo production rates were analysed using ANOVA. Mann-Whitney U test was used for embryo quality evaluation.
Different maturation protocols did not interfere (P>0.05) either on maturation or on embryo quality or production rates.
Embryo quality was higher (P=0.004) when fertilization was accomplished with fresh semen (good: FS=40.1±8.0% vs
TS=32.9±5.6%; fair: FS=20.1±4.7% vs TS=35.7±5.8%; bad: FS=39.8±9.8% vs TS=31.4±7.6%).
Preliminar results show that ram fresh semen can be easily used for in vitro fertilization and improves the quality of
produced embryos
Mobile Communication Signatures of Unemployment
The mapping of populations socio-economic well-being is highly constrained by
the logistics of censuses and surveys. Consequently, spatially detailed changes
across scales of days, weeks, or months, or even year to year, are difficult to
assess; thus the speed of which policies can be designed and evaluated is
limited. However, recent studies have shown the value of mobile phone data as
an enabling methodology for demographic modeling and measurement. In this work,
we investigate whether indicators extracted from mobile phone usage can reveal
information about the socio-economical status of microregions such as districts
(i.e., average spatial resolution < 2.7km). For this we examine anonymized
mobile phone metadata combined with beneficiaries records from unemployment
benefit program. We find that aggregated activity, social, and mobility
patterns strongly correlate with unemployment. Furthermore, we construct a
simple model to produce accurate reconstruction of district level unemployment
from their mobile communication patterns alone. Our results suggest that
reliable and cost-effective economical indicators could be built based on
passively collected and anonymized mobile phone data. With similar data being
collected every day by telecommunication services across the world,
survey-based methods of measuring community socioeconomic status could
potentially be augmented or replaced by such passive sensing methods in the
future
Identification and antimicrobial resistance profile of bacteria isolated from the
The main cause of infertility in mares is endometritis, characterized by acute or chronic inflammation of the endometrium. One of the main causes of the occurrence of inflammation in the endometrium is the response to bacterial infection. When the infection overcomes the defense capacity of the host it leads to the development of bacterial endometritis, often caused by Streptococcus equi subsp. zooepidemicus, an opportunistic pathogen. The present study aimed to evaluate the presence of bacteria in the uterus of mares before insemination. For this purpose, uterine washings were performed with sterile saline solution. Samples were centrifuged at 8000 g for 10min at 4oC, and the pellet was streaked onto Blood Agar and MacConkey plates. The obtained isolates were identified using biochemical (VITEK 2 Compac and API, Biomerieux) and molecular identification methodologies (16S rRNA gene sequencing). Moreover, antimicrobial susceptibility tests (AST) were performed with VITEK 2 Compac, for fast growing bacteria and disc diffusion method, for fastidious bacteria. A total of 62 uterine washings were analyzed. A positive culture was obtained in 66% of the specimens, resulting in 57 isolates, with 57% of Gram-positive bacteria isolated. Regarding prevalence, the most frequently isolated genera were Streptococcus (33%), Escherichia (25%) and Staphylococcus (18%), while the most frequent species was Escherichia coli, followed by S. equi subsp. zooepidemicus. Most Gram-positive bacteria were sensitive to the following three antimicrobials, namely tetracycline, ceftiofur, and enrofloxacin. Regarding Gram-negative bacteria, over 90% of the isolates were sensitive to ceftiofur and gentamycin, while over 60% of the isolates were sensitive to enrofloxacin
A universal model for mobility and migration patterns
Introduced in its contemporary form by George Kingsley Zipf in 1946, but with
roots that go back to the work of Gaspard Monge in the 18th century, the
gravity law is the prevailing framework to predict population movement, cargo
shipping volume, inter-city phone calls, as well as bilateral trade flows
between nations. Despite its widespread use, it relies on adjustable parameters
that vary from region to region and suffers from known analytic
inconsistencies. Here we introduce a stochastic process capturing local
mobility decisions that helps us analytically derive commuting and mobility
fluxes that require as input only information on the population distribution.
The resulting radiation model predicts mobility patterns in good agreement with
mobility and transport patterns observed in a wide range of phenomena, from
long-term migration patterns to communication volume between different regions.
Given its parameter-free nature, the model can be applied in areas where we
lack previous mobility measurements, significantly improving the predictive
accuracy of most of phenomena affected by mobility and transport processes.Comment: Main text and supplementary informatio
A loss-of-function homozygous mutation in DDX59 implicates a conserved DEAD-box RNA helicase in nervous system development and function.
We report on a homozygous frameshift deletion in DDX59 (c.185del: p.Phe62fs*13) in a family presenting with orofaciodigital syndrome phenotype associated with a broad neurological involvement characterized by microcephaly, intellectual disability, epilepsy, and white matter signal abnormalities associated with cortical and subcortical ischemic events. DDX59 encodes a DEAD-box RNA helicase and its role in brain function and neurological diseases is unclear. We showed a reduction of mutant cDNA and perturbation of SHH signaling from patient-derived cell lines; furthermore, analysis of human brain gene expression provides evidence that DDX59 is enriched in oligodendrocytes and might act within pathways of leukoencephalopathies-associated genes. We also characterized the neuronal phenotype of the Drosophila model using mutant mahe, the homolog of human DDX59, and showed that mahe loss-of-function mutant embryos exhibit impaired development of peripheral and central nervous system. Taken together, our results support a conserved role of this DEAD-box RNA helicase in neurological function
The Collaborative Image of The City: Mapping the Inequality of Urban Perception
A traveler visiting Rio, Manila or Caracas does not need a report to learn that these cities are unequal; she can see it directly from the taxicab window. This is because in most cities inequality is conspicuous, but also, because cities express different forms of inequality that are evident to casual observers. Cities are highly heterogeneous and often unequal with respect to the income of their residents, but also with respect to the cleanliness of their neighborhoods, the beauty of their architecture, and the liveliness of their streets, among many other evaluative dimensions. Until now, however, our ability to understand the effect of a city's built environment on social and economic outcomes has been limited by the lack of quantitative data on urban perception. Here, we build on the intuition that inequality is partly conspicuous to create quantitative measure of a city's contrasts. Using thousands of geo-tagged images, we measure the perception of safety, class and uniqueness; in the cities of Boston and New York in the United States, and Linz and Salzburg in Austria, finding that the range of perceptions elicited by the images of New York and Boston is larger than the range of perceptions elicited by images from Linz and Salzburg. We interpret this as evidence that the cityscapes of Boston and New York are more contrasting, or unequal, than those of Linz and Salzburg. Finally, we validate our measures by exploring the connection between them and homicides, finding a significant correlation between the perceptions of safety and class and the number of homicides in a NYC zip code, after controlling for the effects of income, population, area and age. Our results show that online images can be used to create reproducible quantitative measures of urban perception and characterize the inequality of different cities.MIT Media Lab Consortiu
A Tale of Many Cities: Universal Patterns in Human Urban Mobility
The advent of geographic online social networks such as Foursquare, where users voluntarily signal their current location, opens the door to powerful studies on human movement. In particular the fine granularity of the location data, with GPS accuracy down to 10 meters, and the worldwide scale of Foursquare adoption are unprecedented. In this paper we study urban mobility patterns of people in several metropolitan cities around the globe by analyzing a large set of Foursquare users. Surprisingly, while there are variations in human movement in different cities, our analysis shows that those are predominantly due to different distributions of places across different urban environments. Moreover, a universal law for human mobility is identified, which isolates as a key component the rank-distance, factoring in the number of places between origin and destination, rather than pure physical distance, as considered in some previous works. Building on our findings, we also show how a rank-based movement model accurately captures real human movements in different cities
Population genetics of wild-type CAG repeats in the Machado-Joseph disease gene in Portugal
To gain insights on the molecular mechanisms
of mutation that led to the emergence of expanded alleles in the MJD gene, by studying the behavior of wild-type alleles and testing the association of its distribution
with the representation of the disease. Methods:
The number of CAG motifs in the MJD gene was determined in a representative sample of 1000 unrelated individuals.
Associations between the repeat size and the
epidemiological representation of MJD were tested. Results:
The allelic profi le of the total sample was in the normal range (13–41 repeats), with mode (CAG) 23 . No intermediate alleles were present. Allelic size distribution showed a negative skew. The correlation between
the epidemiological representation of MJD in each district and the frequency of small, medium and large normal alleles was not signifi cant. Further correlations performed
grouping the districts also failed to produce
signifi cant results. Conclusions: The absence of association between the size of the repeats and the representation of MJD demonstrates that prevalence is not an indirect refl ection of the frequency of large normal alleles.
Globally the results obtained are in accordance with a model that postulates the occurrence of a few mutations on the basis of most of the MJD cases worldwide
Cement leakage causes potential thermal injury in vertebroplasty
<p>Abstract</p> <p>Background</p> <p>Percutaneous vertebroplasty by injecting PMMA bone cement into the fractured vertebrae has been widely accepted in treatment of spinal compression fracture. However, the exothermic polymerization of bone cement may cause osseous or neural tissue injury. This study is thus designed to evaluate the potential risk of thermal damage in percutaneous vertebroplasty.</p> <p>Method</p> <p>Twelve porcine vertebrae were immersed in 37°C saline for the experiment. In the first stage of the study, vertebroplasty without cement leakage (control group, n = 6) was simulated. The anterior cortex, foramen, posterior cortex and the center of the vertebral body were selected for temperature measurement. Parameters including peak temperature and duration above 45°C were recorded. In the second stage, a model (n = 6) simulating bone cement leaking into the spinal canal was designed. The methods for temperature measurement were identical to those used in the first stage.</p> <p>Results</p> <p>In Stage 1 of the study (vertebroplasty of the porcine vertebral body in the absence of cement leakage), the average maximal temperature at the anterior cortex was 42.4 ± 2.2°C; at the neural foramen 39.5 ± 2.1°C; at the posterior cortex 40.0 ± 2.5°C and at the vertebral center, 68.1 ± 3.4°C. The average time interval above 45°C was 0 seconds at the anterior cortex; at the neural foramen, 0 seconds; at the posterior cortex, 0 seconds and at the vertebral center, 223 seconds. Thus, except at the core of the bone cement, temperatures around the vertebral body did not exceed 45°C. In Stage 2 of the study (cement leakage model), the average maximal temperature at the anterior cortex was 42.7 ± 2.4°C; at the neural foramen, 41.1 ± 0.4°C; at the posterior cortex, 59.1 ± 7.6°C and at the vertebral center, 77.3 ± 5.7°C. The average time interval above 45°C at the anterior cortex was 0 seconds; at the neural foramen, 0 seconds; at the posterior cortex, 329.3 seconds and at the vertebral center, 393.2 seconds. Based on these results, temperatures exceeded 45°C at the posterior cortex and at the vertebral center.</p> <p>Conclusions</p> <p>The results indicated that, for bone cement confined within the vertebra, curing temperatures do not directly cause thermal injury to the nearby soft tissue. If bone cement leaks into the spinal canal, the exothermic reaction at the posterior cortex might result in thermal injury to the neural tissue.</p
Human Mobility in a Continuum Approach
Human mobility is investigated using a continuum approach that allows to
calculate the probability to observe a trip to anyarbitrary region, and the
fluxes between any two regions. The considered description offers a general and
unified framework, in which previously proposed mobility models like the
gravity model, the intervening opportunities model, and the recently introduced
radiation model are naturally resulting as special cases. A new form of
radiation model is derived and its validity is investigated using observational
data offered by commuting trips obtained from the United States census data
set, and the mobility fluxesextracted from mobile phone data collected in a
western European country. The new modeling paradigm offered by this description
suggests that the complex topological features observed in large mobility and
transportation networks may be the result of a simple stochastic process taking
place on an inhomogeneous landscape.Comment: 13 pages, 3 figure
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