22,424 research outputs found
Genetic and Environmental Contributions to Body Mass Index: Comparative Analysis of Monozygotic Twins, Dizygotic Twins and Same-Age Unrelated Siblings
Background—Earlier studies have established that a substantial percentage of variance in obesity-related phenotypes is explained by genetic components. However, only one study has used both virtual twins (VTs) and biological twins and was able to simultaneously estimate additive genetic, non-additive genetic, shared environmental and unshared environmental components in body mass index (BMI). Our current goal was to re-estimate four components of variance in BMI, applying a more rigorous model to biological and virtual multiples with additional data. Virtual multiples share the same family environment, offering unique opportunities to estimate common environmental influence on phenotypes that cannot be separated from the non-additive genetic component using only biological multiples.
Methods—Data included 929 individuals from 164 monozygotic twin pairs, 156 dizygotic twin pairs, five triplet sets, one quadruplet set, 128 VT pairs, two virtual triplet sets and two virtual quadruplet sets. Virtual multiples consist of one biological child (or twins or triplets) plus one same-aged adoptee who are all raised together since infancy. We estimated the additive genetic, non-additive genetic, shared environmental and unshared random components in BMI using a linear mixed model. The analysis was adjusted for age, age2, age3, height, height2, height3, gender and race.
Results—Both non-additive genetic and common environmental contributions were significant in our model (P-values \u3c 0.0001). No significant additive genetic contribution was found. In all, 63.6% (95% confidence interval (CI) 51.8–75.3%) of the total variance of BMI was explained by a non-additive genetic component, 25.7% (95% CI 13.8–37.5%) by a common environmental component and the remaining 10.7% by an unshared component.
Conclusion—Our results suggest that genetic components play an essential role in BMI and that common environmental factors such as diet or exercise also affect BMI. This conclusion is consistent with our earlier study using a smaller sample and shows the utility of virtual multiples for separating non-additive genetic variance from common environmental variance
Surgical Video Motion Magnification with Suppression of Instrument Artefacts
Video motion magnification can make blood vessels in surgical video more apparent by exaggerating their pulsatile motion and could prevent inadvertent damage and bleeding due to their increased prominence. It could also indicate the success of restricting blood supply to an organ when using a vessel clamp. However, the direct application to surgical video could result in aberration artefacts caused by its sensitivity to residual motion from the surgical instruments and would impede its practical usage in the operating theatre. By storing the previously obtained jerk filter response of each spatial component of each image frame - both prior to surgical instrument introduction and adhering to a Eulerian frame of reference - it is possible to prevent such aberrations from occurring. The comparison of the current readings to the prior readings of a single cardiac cycle at the corresponding cycle point, are used to determine if motion magnification should be active for each spatial component of the surgical video at that given point in time. In this paper, we demonstrate this technique and incorporate a scaling variable to loosen the effect which accounts for variabilities and misalignments in the temporal domain. We present promising results on endoscopic transnasal transsphenoidal pituitary surgery with a quantitative comparison to recent methods using Structural Similarity (SSIM), as well as qualitative analysis by comparing spatio-temporal cross sections of the videos and individual frames
REDD+ on the rocks? Conflict over forest and politics of justice in Vietnam
In Vietnam, villagers involved in a REDD+ (reduced emissions from deforestation and forest degradation) pilot protect areas with rocks which have barely a tree on them. The apparent paradox indicates how actual practices differ from general ideas about REDD+ due to ongoing conflict over forest, and how contestations over the meaning of justice are a core element in negotiations over REDD+. We explore these politics of justice by examining how the actors involved in the REDD+ pilot negotiate the particular subjects, dimensions, and authority of justice considered relevant, and show how politics of justice are implicit to practical decisions in project implementation. Contestations over the meaning of justice are an important element in the practices and processes constituting REDD+ at global, national and local levels, challenging uniform definitions of forest justice and how forests ought to be managed
Embodiment in a Child-Like Talking Virtual Body Influences Object Size Perception, Self-Identification, and Subsequent Real Speaking
People’s mental representations of their own body are malleable and continuously updated through sensory cues. Altering one’s body-representation can lead to changes in object perception and implicit attitudes. Virtual reality has been used to embody adults in the body of a 4-year-old child or a scaled-down adult body. Child embodiment was found to cause an overestimation of object sizes, approximately double that during adult embodiment, and identification of the self with child-like attributes. Here we tested the contribution of auditory cues related to one’s own voice to these visually-driven effects. In a 2 × 2 factorial design, visual and auditory feedback on one’s own body were varied across conditions, which included embodiment in a child or scaled-down adult body, and real (undistorted) or child-like voice feedback. The results replicated, in an older population, previous findings regarding size estimations and implicit attitudes. Further, although auditory cues were not found to enhance these effects, we show that the strength of the embodiment illusion depends on the child-like voice feedback being congruent or incongruent with the age of the virtual body. Results also showed the positive emotional impact of the illusion of owning a child’s body, opening up possibilities for health applications
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On the road to eliminate malaria in Sri Lanka: lessons from history, challenges, gaps in knowledge and research needs
Malaria is one of the most important tropical diseases that has caused devastation throughout the history of mankind. Malaria eradication programmes in the past have had many positive effects but failed to wipe out malaria from most tropical countries, including Sri Lanka. Encouraged by the impressive levels of reduction in malaria case numbers during the past decade, Sri Lanka has launched a programme to eliminate malaria by year 2014. This article reviews the historical milestones associated with the malaria eradication programme that failed subsequently and the events that led to the launch of the ongoing malaria elimination plans at national-level and its strategies that are operational across the entire country. The existing gaps in knowledge are also discussed together with the priority areas for research to fill in these gaps that are posing as challenges to the envisaged goal of wiping out malaria from this island nation
Paraganglioma in a young female. Are we missing a possible inherited aetiology? A case report
Proline biosynthesis regulates proline transport in Staphylococcus aureus.
Staphylococcus aureus is metabolically diverse with the ability to rapidly adapt to a vast array of nutrient sources. This allows the pathogen to colonize a variety of niches in the host. For instance, S. aureus is the leading cause of skin and soft tissue infections, a niche that has been shown to become glucose-depleted over the course of an infection. Previous studies have shown that in niches where glucose is deficient, S. aureus utilizes peptides and free amino acids as nutrient sources. Primarily, these amino acids include glutamate and amino acids that can serve as substrates for glutamate synthesis. While arginine and histidine serve as substrates in glutamate synthesis, proline is the primary source of glutamate. Indeed, S. aureus utilizes proline as a secondary carbon source only when glucose is absent, and it can be synthesized from arginine or acquired via proline transporters from its environment. Although S. aureus encodes two putative pathways for proline biosynthesis, it has been shown that pyrroline-5-carboxylate reductase (encoded by proC) is the sole proline biosynthetic pathway in S. aureus. Studies from our laboratory have revealed that despite encoding five putative proline transporters (B7H15_03660, opuC, opuD, proP, putP), only two of the transporters, PutP and B7H15_03660 are responsible for a majority of proline transport under the laboratory conditions tested. Surprisingly, when we introduced the proC mutation into the B7H15_03660 putP double mutant, we observed proline-dependent growth, even though the primary proline transporters and proline biosynthetic pathway were knocked-out. In contrast, a transporter null ΔproC strain was unable to grow. These data suggest that inhibiting proline biosynthesis alters proline transport, and therefore one or more of the additional transporters, OpuC, OpuD, and/or ProP, are activated under these conditions. After introducing opuC, opuD, and/or proP mutations into the Δ03660 ΔputP ΔproC strain, we found that both OpuC and ProP are important for proline transport. Additionally, we observed proline-dependent growth in a proline transporter null ΔproC strain when high amounts of exogenous proline are added to the media. This growth appears to be due to an acquired mutation and will be studied more in the future. Overall these studies have revealed that proline transport is tightly linked to proline biosynthesis.https://digitalcommons.unmc.edu/surp2021/1021/thumbnail.jp
Is My Exercise Partner Similar Enough? Partner Characteristics as a Moderator of the Köhler Effect in Exergames
Objective: Recent research has shown the Köhler motivation gain effect (working at a task with a more capable partner where one's performance is indispensable to the group) leads to greater effort in partnered exercise videogame play. The purpose of this article was to examine potential moderators of the Köhler effect by exploring dissimilarities in one's partner's appearance, namely, having an older partner (compared with a same-age partner) and having a heavier-weight partner (compared with a same-weight partner).
Subjects and Methods: One hundred fifty-three male and female college students completed a series of plank exercises using the “EyeToy: Kinetic™” for the PlayStation® 2 (Sony, Tokyo, Japan). Participants first completed the exercises individually and, after a rest, completed the same exercises with a virtually present partner. Exercise persistence, subjective effort, self-efficacy beliefs, enjoyment, and intentions to exercise were recorded and analyzed.
Results: A significant Köhler motivation gain was observed in all partner conditions (compared with individual controls) such that participants with a partner held the plank exercises longer (P<0.001) and reported higher subjective effort (P<0.01). These results were unmoderated by partner's age and weight, with one exception: Males tended to persist longer when paired with an obese partner (P=0.08).
Conclusions: These results suggest that differences in age and weight do not attenuate the Köhler effect in exergames and may even strengthen it
Differentiation of human fetal mesenchymal stem cells into cells with an oligodendrocyte phenotype
This article is available open access through the publisher’s website at the link below. Copyright @ 2009 Landes Bioscience.The potential of mesenchymal stem cells (MSC) to differentiate into neural lineages has raised the possibility of autologous cell transplantation as a therapy for neurodegenerative diseases. We have identified a population of circulating human fetal mesenchymal stem cells (hfMSC) that are highly proliferative and can readily differentiate into mesodermal lineages such as bone, cartilage, fat and muscle. Here, we demonstrate for the first time that primary hfMSC can differentiate into cells with an oligodendrocyte phenotype both in vitro and in vivo. By exposing hfMSC to neuronal conditioned medium or by introducing the pro-oligodendrocyte gene, Olig-2, hfMSC adopted an oligodendrocyte-like morphology, expressed oligodendrocyte markers and appeared to mature appropriately in culture. Importantly we also demonstrate the differentiation of a clonal population of hfMSC into both mesodermal (bone) and ectodermal (oligodendrocyte) lineages. In the developing murine brain transplanted hfMSC integrated into the parenchyma but oligodendrocyte differentiation of these naïve hfMSC was very low. However, the proportion of cells expressing oligodendrocyte markers increased significantly (from 0.2% to 4%) by pre-exposing the cells to differentiation medium in vitro prior to transplantation. Importantly, the process of in vivo differentiation occurred without cell fusion. These findings suggest that hfMSC may provide a potential source of oligodendrocytes for study and potential therapy
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