1,294 research outputs found

    A utilização de sémen fresco na fertilização in vitro de embriões ovinos melhora a qualidade dos blastocistos na raça portuguesa Merino

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    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

    The statistical neuroanatomy of frontal networks in the macaque

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    We were interested in gaining insight into the functional properties of frontal networks based upon their anatomical inputs. We took a neuroinformatics approach, carrying out maximum likelihood hierarchical cluster analysis on 25 frontal cortical areas based upon their anatomical connections, with 68 input areas representing exterosensory, chemosensory, motor, limbic, and other frontal inputs. The analysis revealed a set of statistically robust clusters. We used these clusters to divide the frontal areas into 5 groups, including ventral-lateral, ventral-medial, dorsal-medial, dorsal-lateral, and caudal-orbital groups. Each of these groups was defined by a unique set of inputs. This organization provides insight into the differential roles of each group of areas and suggests a gradient by which orbital and ventral-medial areas may be responsible for decision-making processes based on emotion and primary reinforcers, and lateral frontal areas are more involved in integrating affective and rational information into a common framework

    Subjective memory complaints in Portuguese young adults: contributions from the adaptation of the prospective and retrospective memory questionnaire

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    Self-report instruments that allow to characterize the frequency of daily memory failures are essential for a comprehensive assessment of memory functioning. In this context, we aimed to provide preliminary evidence of validity and reliability for the European Portuguese adaptation of the Prospective and Retrospective Memory Questionnaire (PRMQ). A total of 1052 healthy participants completed an online survey with the PRMQ. The exploration of the construct validity suggested the tripartite model with a general memory, a prospective memory, and a retrospective memory factors to have the best adjustment to the data. Measurement invariance across age and sex groups was also verified. The questionnaire revealed good convergent validity with a general self-report measure of memory (0.778 < r < 0.853), and satisfactory values of internal consistency (0.779 < Cronbach's alpha < 0.887) and of test-retest reliability (0.815 < r < 0.852). There were no prominent effects of sex and age in the PRMQ scores. Although the sample encompassed mainly younger and highly educated adults, this study presented the first evidence of validity and reliability for the European Portuguese version of the questionnaire.- This work was funded by the Portuguese Foundation for Science and Technology (FCT) under a Doctoral grant (PD/BD/105964/2014) of the FCT PhD Programmes with the support of the Operational Programme for Human Capital (POCH). It was partially conducted at Psychology Research Centre (UID/PSI/01662/2013), University of Minho, supported by the FCT and the Portuguese Ministry of Education and Science through national funds and co-financed by FEDER through COMPETE2020 under the Portugal2020 Partnership Agreement (POCI-01-0145-FEDER-007653). The authors would like to thank particularly the original authors of the questionnaire, and the institutions that responsively helped to spread the word regarding the study, namely University of Porto and University of Beira Anterior. We would like to acknowledge Joana Coutinho, Alberto Crego, and Ana Seara-Cardoso for aiding with the translation procedures. Special thanks are also due to the members of the Neuropsychophysiology Laboratory and the Human Memory Research Group of the University of Minho for the feedback in the early stages of the questionnaire adaptation. The authors would like to acknowledge all the participants that collaborated in this work, and the reviewers whose comments helped to improve the manuscript

    A Smart Wireless Car Ignition System for Vehicle Security

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    Copyright: © 2017 Haider A, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.The paper proposes a novel car ignition system to replace the traditional wired technology and enhance vehicle security. This new system uses wireless transmissions to start the engine and hence eliminates the ignition wire behind the dashboard. It also allows the user to set a password of his/her choice to keep the system protected. A theft alarm that goes ‘’ON’’ when an unusual activity is sensed and/or when the wrong password is attempted to unlock the system is integrated in the system. Moreover, important factors such as economic feasibility, adaptability to the new vehicle technologies and customers’ preferences have been taken into consideration in the design of the proposed vehicle security system.Peer reviewedFinal Published versio

    Activation of ERK1/2 MAP kinases in familial amyloidotic polyneuropathy

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    J Neurochem. 2006 Apr;97(1):151-61. Epub 2006 Mar 3. Activation of ERK1/2 MAP kinases in familial amyloidotic polyneuropathy. Monteiro FA, Sousa MM, Cardoso I, do Amaral JB, Guimarães A, Saraiva MJ. Molecular Neurobiology, Instituto de Biologia Celular e Molecular, ICBAS, University of Porto, and Estomatology, Maxillofacial Surgery, Hospital Geral de Santo António, Portugal. Abstract Familial amyloidotic polyneuropathy (FAP) is a neurodegenerative disorder characterized by the extracellular deposition of transthyretin (TTR), especially in the PNS. Given the invasiveness of nerve biopsy, salivary glands (SG) from FAP patients were used previously in microarray analysis; mitogen-activated protein (MAP) kinase phosphatase 1 (MKP-1) was down-regulated in FAP. Results were validated by RT-PCR and immunohistochemistry both in SG and in nerve biopsies of different stages of disease progression. MKP-3 was also down-regulated in FAP SG biopsies. Given the relationship between MKPs and MAPKs, the latter were investigated. Only extracellular signal-regulated kinases 1/2 (ERK1/2) displayed increased activation in FAP SG and nerves. ERK1/2 kinase (MEK1/2) activation was also up-regulated in FAP nerves. In addition, an FAP transgenic mouse model revealed increased ERK1/2 activation in peripheral nerve affected with TTR deposition when compared to control animals. Cultured rat Schwannoma cell line treatment with TTR aggregates stimulated ERK1/2 activation, which was partially mediated by the receptor for advanced glycation end-products (RAGE). Moreover, caspase-3 activation triggered by TTR aggregates was abrogated by U0126, a MEK1/2 inhibitor, indicating that ERK1/2 activation is essential for TTR aggregates-induced cytotoxicity. Taken together, these data suggest that abnormally sustained activation of ERK in FAP may represent an early signaling cascade leading to neurodegeneration. PMID: 16515552 [PubMed - indexed for MEDLINE

    Contrasting prefrontal cortex contributions to episodic memory dysfunction in behavioural variant frontotemporal dementia and alzheimer's disease

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    Recent evidence has questioned the integrity of episodic memory in behavioural variant frontotemporal dementia (bvFTD), where recall performance is impaired to the same extent as in Alzheimer's disease (AD). While these deficits appear to be mediated by divergent patterns of brain atrophy, there is evidence to suggest that certain prefrontal regions are implicated across both patient groups. In this study we sought to further elucidate the dorsolateral (DLPFC) and ventromedial (VMPFC) prefrontal contributions to episodic memory impairment in bvFTD and AD. Performance on episodic memory tasks and neuropsychological measures typically tapping into either DLPFC or VMPFC functions was assessed in 22 bvFTD, 32 AD patients and 35 age- and education-matched controls. Behaviourally, patient groups did not differ on measures of episodic memory recall or DLPFC-mediated executive functions. BvFTD patients were significantly more impaired on measures of VMPFC-mediated executive functions. Composite measures of the recall, DLPFC and VMPFC task scores were covaried against the T1 MRI scans of all participants to identify regions of atrophy correlating with performance on these tasks. Imaging analysis showed that impaired recall performance is associated with divergent patterns of PFC atrophy in bvFTD and AD. Whereas in bvFTD, PFC atrophy covariates for recall encompassed both DLPFC and VMPFC regions, only the DLPFC was implicated in AD. Our results suggest that episodic memory deficits in bvFTD and AD are underpinned by divergent prefrontal mechanisms. Moreover, we argue that these differences are not adequately captured by existing neuropsychological measures

    The origin of large molecules in primordial autocatalytic reaction networks

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    Large molecules such as proteins and nucleic acids are crucial for life, yet their primordial origin remains a major puzzle. The production of large molecules, as we know it today, requires good catalysts, and the only good catalysts we know that can accomplish this task consist of large molecules. Thus the origin of large molecules is a chicken and egg problem in chemistry. Here we present a mechanism, based on autocatalytic sets (ACSs), that is a possible solution to this problem. We discuss a mathematical model describing the population dynamics of molecules in a stylized but prebiotically plausible chemistry. Large molecules can be produced in this chemistry by the coalescing of smaller ones, with the smallest molecules, the `food set', being buffered. Some of the reactions can be catalyzed by molecules within the chemistry with varying catalytic strengths. Normally the concentrations of large molecules in such a scenario are very small, diminishing exponentially with their size. ACSs, if present in the catalytic network, can focus the resources of the system into a sparse set of molecules. ACSs can produce a bistability in the population dynamics and, in particular, steady states wherein the ACS molecules dominate the population. However to reach these steady states from initial conditions that contain only the food set typically requires very large catalytic strengths, growing exponentially with the size of the catalyst molecule. We present a solution to this problem by studying `nested ACSs', a structure in which a small ACS is connected to a larger one and reinforces it. We show that when the network contains a cascade of nested ACSs with the catalytic strengths of molecules increasing gradually with their size (e.g., as a power law), a sparse subset of molecules including some very large molecules can come to dominate the system.Comment: 49 pages, 17 figures including supporting informatio

    Norfloxacin sesquihydrate

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    In the crystal structure of the title compound [systematic name: 1-ethyl-6-fluoro-4-oxo-7-(piperazin-4-ium-1-yl)-1,4-dihydro­quinoline-3-carboxyl­ate sesquihydrate], C16H18FN3O3·1.42H2O, N—H⋯O and O—H⋯O hydrogen bonds assemble the mol­ecules in a two-dimensional layered corrugated sheet structure parallel to the b axis. The water mol­ecules are disordered [occupancies 0.741 (11) and 0.259 (11)]

    A proposal for a coordinated effort for the determination of brainwide neuroanatomical connectivity in model organisms at a mesoscopic scale

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    In this era of complete genomes, our knowledge of neuroanatomical circuitry remains surprisingly sparse. Such knowledge is however critical both for basic and clinical research into brain function. Here we advocate for a concerted effort to fill this gap, through systematic, experimental mapping of neural circuits at a mesoscopic scale of resolution suitable for comprehensive, brain-wide coverage, using injections of tracers or viral vectors. We detail the scientific and medical rationale and briefly review existing knowledge and experimental techniques. We define a set of desiderata, including brain-wide coverage; validated and extensible experimental techniques suitable for standardization and automation; centralized, open access data repository; compatibility with existing resources, and tractability with current informatics technology. We discuss a hypothetical but tractable plan for mouse, additional efforts for the macaque, and technique development for human. We estimate that the mouse connectivity project could be completed within five years with a comparatively modest budget.Comment: 41 page

    How does performing demanding activities influence prospective memory? A systematic review

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    This paper is the first systematic review on the role of ongoing task load in prospective remembering, which was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Forty articles published between 1995 and 2020 were included. They evaluated prospective memory (PM) performance (i.e., the ability to remember to execute a delayed intention) in adult samples aged between 19 and 50 years old when the PM cue appeared under cognitively demanding conditions.The results revealed that people are more likely to fail to remember to perform a delayed intention at the appropriate circumstances or time in the future when their cognitive resources are taxed by demanding ongoing activities. We conclude the review by highlighting that the degree of working memory and executive resources seems to account for some of the discrepant findings and by proposing directions for future research.- This project was founded by the Portuguese Foundation for Science and Technology (FCT, Portugal) with the grant BD/123421/2016 awarded to Patricia Matos and with thegrant PD/BD/105964/2014 awarded to Diana R. Pereira. This study was conducted at the Psychology Research Centre (UID/PSI/01662/2019), University of Minho, and supported by the Portuguese Ministry of Science, Technology and Higher Education, through the State Budget (UID/PSI/01662/2019). Correspondence concerning this article should be addressed to Patricia Fernanda Ferreira Matos, School of Psychology, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
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