7,131 research outputs found
An ecological framework for the development of a national MPA network
Isolated marine protected areas (MPAs) may not be enough to sustain viable populations of marine species, particularly the many small coastal MPAs which resulted due to social, economic and political constraints. Properly designed MPA networks can circumvent such limitations due to their potential synergistic positive effects, but this crucial step is frequently obstructed by lack of baseline ecological information. In this paper, we use systematic conservation planning on European Nature Information System coastal habitat information available for Portugal to demonstrate how an ecologically coherent nation-wide MPA network can be designed. We used the software Marxan to obtain near optimal solutions for each of three pre-determined conservation targets (10%, 30% and 50% protection) while maintaining the cost of including conservation units as low as possible. Marxan solutions were subsequently optimized with MinPatch by keeping each MPA above a minimum size that reflects the existing information on habitat use by some key marine fishes. Results show that 10% protection for all habitats would only require a relativelly small increase in the number (from 6 to 10) and area (from 479 km(2) to 509 km(2)) of already existing MPAs in mainland Portugal whereas substantial increases would be required to achieve the 50% target. This rather simple approach offers the added benefit of allowing design improvement as more relevant ecological information becomes available, including deeper habitat mapping across the whole continental shelf, allowing a coherent, adaptive and inclusive optimal MPA network to be designed.info:eu-repo/semantics/publishedVersio
Accidental Father-to-Son HIV-1 Transmission During the Seroconversion Period
A 4-year-old child born to an HIV-1 seronegative mother was diagnosed with HIV-1, the main risk factor being transmission from the child's father who was seroconverting at the time of the child's birth. In the context of a forensic investigation, we aimed to identify the source of infection of the child and date of the transmission event. Samples were collected from the father and child at two time points about 4 years after the child's birth. Partial segments of three HIV-1 genes (gag, pol, and env) were sequenced and maximum likelihood (ML) and Bayesian methods were used to determine direction and estimate date of transmission. Neutralizing antibodies were determined using a single cycle assay. Bayesian trees displayed a paraphyletic-monophyletic topology in all three genomic regions, with the father's host label at the root, which is consistent with father-to-son transmission. ML trees found similar topologies in gag and pol and a monophyletic-monophyletic topology in env. Analysis of the time of the most recent common ancestor of each HIV-1 gene population indicated that the child was infected shortly after the father. Consistent with the infection history, both father and son developed broad and potent HIV-specific neutralizing antibody responses. In conclusion, the direction of transmission implicated the father as the source of transmission. Transmission occurred during the seroconversion period when the father was unaware of the infection and was likely accidental. This case shows how genetic, phylogenetic, and serological data can contribute for the forensic investigation of HIV transmission.info:eu-repo/semantics/publishedVersio
Recombination confounds the early evolutionary history of human immunodeficiency virus type 1: Subtype G is a circulating recombinant form
Human immunodeficiency virus type I (HIV-1) is classified in nine subtypes (A to D, F, G, H, J, and K), a number of subsubtypes, and several circulating recombinant forms (CRFs). Due to the high level of genetic diversity within HIV-1 and to its worldwide distribution, this classification system is widely used in fields as diverse as vaccine development, evolution, epidemiology, viral fitness, and drug resistance. Here, we demonstrate how the high recombination rates of HIV-1 may confound the study of its evolutionary history and classification. Our data show that subtype G, currently classified as a pure subtype, has in fact a recombinant history, having evolved following recombination between subtypes A and J and a putative subtype G parent. In addition, we find no evidence for recombination within one of the lineages currently classified as a CRF, CRF02 -AG. Our analysis indicates that CRF02_AG was the parent of the recombinant subtype G, rather than the two having the opposite evolutionary relationship, as is currently proposed. Our results imply that the current classification of HIV-1 subtypes and CRFs is an artifact of sampling history, rather than reflecting the evolutionary history of the virus. We suggest a reanalysis of all pure subtypes and CRFs in order to better understand how high rates of recombination have influenced HIV-1 evolutionary history.</p
A novel haemoglobin variant mimicking cyanotic congenital heart disease
Screening for critical congenital heart defects in newborn babies can aid in early recognition, with the prospect of improved outcome. However, as this universal newborn screening is implemented, there will be an increasing number of false-positive results. In order to avoid multiple investigations and uncertainty, an haemoglobin (Hb) variant must be included in the differential diagnosis in otherwise well newborns with low oxygen saturation by pulse oximetry. We describe a novel fetal Hb variant (heterozygous γ-globin gene (HBG1) mutation in exon 2 c.202G>A (p.Val68Met)) identified in a newborn with positive pulse oximetry screening for congenital heart disease.info:eu-repo/semantics/publishedVersio
Combined association and linkage analysis applied to the APOE locus.
Combined association and linkage analysis is a powerful tool for pinpointing functional quantitative traits (QTLs) responsible for regions of significant linkage identified in genome-wide scans. We applied this technique to apoE plasma levels and the APOEε2/ε3/ε4 polymorphism in two Dutch twin cohorts of different age ranges. Across chromosome 19, short tandem repeats and the APOEε2/ε3/ε4 polymorphism were genotyped in adolescent (aged 13-22 years) and adult (aged 34-62 years) Dutch twins. In both samples, evidence for indicative linkage with plasma apoE levels was found (maximum LOD score (MLS)=0.8, MLS=2.5, respectively) at 19q13.32. These linkage regions included the APOE locus. As expected, the APOEε2/ε3/ε4 polymorphism was strongly associated with apoE plasma levels in both samples. An extension of the between/within families association test developed by Fulker et al. ([1999] Am. J. Hum. Genet. 64:259-267) showed that these associations were not due to population stratification. The combined association and linkage analyses revealed that the association of the APOEε2/ε3/ε4 polymorphism with apoE plasma levels completely explained the linkage in the adolescent twins and partly in the adult twins. © 2004 Wiley-Liss, Inc
Orthopantomography contribution to prevent isquemic stroke
Objectives: The ortopantomography (OPG) can be a valuable way for an early detection of calcified atheroma plaques, thus contributing for a preliminary stroke risk evaluation. The study looks for the existence of calcified atheroma plates through the use of OPG, comparing the results with the stenosis percentage found through eco-doppler. It has been analyzed the correlation of the number of years as a smoker, arterial hypertension and body mass index, against the risk of having calcified atheroma plaques. Study Design: Observational, transversal and prospective study with 84 patients from the Dental Center of Hospital Particular de Lisboa. First the patients answered to an inquiry and them they were submitted to an OPG and an eco-doppler. Results and Conclusions: It is possible to detect calcified atheroma plaques in the carotid artery through an OPG and patients who have them have got a fifteen fold greater risk of suffering from carotid stenosis. In this study, it has been confirmed the increase in carotid stenosis for long term smokers (OR = 1,033, n=18, 42,9%). The study results show that hypertension patients have a probability 5,426 greater than normal of developing atheroma plaques (with sig=0,049). Amid analyzed patients, the correlation between obesity and the existence of carotid atheroma plaques was significant, although negative (sig=0,047). OPG can help find patients with higher risk of isquemic strok
A fine-tuned global distribution dataset of marine forests
Species distribution records are a prerequisite to follow climate-induced range shifts across space and time. However, synthesizing information from various sources such as peer-reviewed literature, herbaria, digital repositories and citizen science initiatives is not only costly and time consuming, but also challenging, as data may contain thematic and taxonomic errors and generally lack standardized formats. We address this gap for important marine ecosystem-structuring species of large brown algae and seagrasses. We gathered distribution records from various sources and provide a fine-tuned dataset with ~2.8 million dereplicated records, taxonomically standardized for 682 species, and considering important physiological and biogeographical traits. Specifically, a flagging system was implemented to signal potentially incorrect records reported on land, in regions with limiting light conditions for photosynthesis, and outside the known distribution of species, as inferred from the most recent published literature. We document the procedure and provide a dataset in tabular format based on Darwin Core Standard (DwC), alongside with a set of functions in R language for data management and visualization.FCT: (SFRH/BPD/111003/2015) / (SFRH/BSAB/150485/2019) / (SFRH/BD/144878/2019)(PTDC/MAREST/6053/2014) / MARFOR (BIODIVERSA/004/2015) / UIDB/04326/2020info:eu-repo/semantics/publishedVersio
Can Orthopantomography be used as a tool for screening of carotid atheromatous pathology and thus be used to help reduce the prevalence of ischemic stroke within the population?
Objective: To assess the possibility of Dentists being able to screen patients with higher risk of vascular diseases.
Materials: Kodak 8000C Orthopantomographer, eco-Doppler Logiq-500 General Electric at the Lisbon Hospital
Particular.
Methods: Assessment of orthopantomographies made to 142 patients aged 50 or more, as well as the existing risk
factors. Conduction of carotid eco-Doppler to patients who appear to have calcified plaques of the atheroma.
Results: Strong dependence between dichotomised age and having the pathology (p = 0.02).Smokers are twice
more likely to present plaques (OR= 2). Being hypertensive increases in about 1.4 the likelihood of having a stroke
(OR= 1.4).
Of the 27 individuals who presented calcifications in the Orthopantomography, they were all submitted to an
eco-Doppler and 21 had the pathology confirmed. 27 individuals, who did not show any plaques in the Orthopantomography,
were randomly selected to be the control group. They were submitted to an eco-Doppler. And 23
confirmed the non-existence of plaques.
Conclusions: Orthopantomography used for assessing the oral cavity reveals more information which should be
the object of the Dentist's attentio
Effects of Pairing in the Pseudo-SU(3) Model
An extended version of the pseudo-SU(3) model which includes both spin and
proton-neutron degrees of freedom is used to study the influence of the pairing
interaction on K-band mixing, B(E2) values and quadrupole moments. Using the
asymmetric rotor model as a backdrop, specific consequences of a many-particle
shell-model based description of these collective properties are demonstrated
and fundamental limits of the collective model's approach are investigated.
Finally, the pseudo-SU(3) model, including representation mixing induced by
pairing, is used to calculate the energies of 140Ce and the results are
compared to experimental data and other theories.Comment: 21 pages, Latex, 11 figures available on request via mail or fax,
accepted by Nucl. Phys.
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