626 research outputs found
Pattern matching through Chaos Game Representation: bridging numerical and discrete data structures for biological sequence analysis
BACKGROUND: Chaos Game Representation (CGR) is an iterated function that bijectively maps discrete sequences into a continuous domain. As a result, discrete sequences can be object of statistical and topological analyses otherwise reserved to numerical systems. Characteristically, CGR coordinates of substrings sharing an L-long suffix will be located within 2(-L )distance of each other. In the two decades since its original proposal, CGR has been generalized beyond its original focus on genomic sequences and has been successfully applied to a wide range of problems in bioinformatics. This report explores the possibility that it can be further extended to approach algorithms that rely on discrete, graph-based representations. RESULTS: The exploratory analysis described here consisted of selecting foundational string problems and refactoring them using CGR-based algorithms. We found that CGR can take the role of suffix trees and emulate sophisticated string algorithms, efficiently solving exact and approximate string matching problems such as finding all palindromes and tandem repeats, and matching with mismatches. The common feature of these problems is that they use longest common extension (LCE) queries as subtasks of their procedures, which we show to have a constant time solution with CGR. Additionally, we show that CGR can be used as a rolling hash function within the Rabin-Karp algorithm. CONCLUSIONS: The analysis of biological sequences relies on algorithmic foundations facing mounting challenges, both logistic (performance) and analytical (lack of unifying mathematical framework). CGR is found to provide the latter and to promise the former: graph-based data structures for sequence analysis operations are entailed by numerical-based data structures produced by CGR maps, providing a unifying analytical framework for a diversity of pattern matching problems
Tissue-specific calibration of extracellular matrix material properties by transforming growth factor-beta and Runx2 in bone is required for hearing
Publisher version: http://www.nature.com/embor/journal/v11/n10/full/embor2010135.htmlDA - 20100917 IS - 1469-3178 (Electronic) IS - 1469-221X (Linking) LA - ENG PT - JOURNAL ARTICLEDA - 20100917 IS - 1469-3178 (Electronic) IS - 1469-221X (Linking) LA - ENG PT - JOURNAL ARTICLEDA - 20100917 IS - 1469-3178 (Electronic) IS - 1469-221X (Linking) LA - ENG PT - JOURNAL ARTICLEPhysical cues, such as extracellular matrix stiffness, direct cell differentiation and support tissue-specific function. Perturbation of these cues underlies diverse pathologies, including osteoarthritis, cardiovascular disease and cancer. However, the molecular mechanisms that establish tissue-specific material properties and link them to healthy tissue function are unknown. We show that Runx2, a key lineage-specific transcription factor, regulates the material properties of bone matrix through the same transforming growth factor-beta (TGFbeta)-responsive pathway that controls osteoblast differentiation. Deregulated TGFbeta or Runx2 function compromises the distinctly hard cochlear bone matrix and causes hearing loss, as seen in human cleidocranial dysplasia. In Runx2(+/-) mice, inhibition of TGFbeta signalling rescues both the material properties of the defective matrix, and hearing. This study elucidates the unknown cause of hearing loss in cleidocranial dysplasia, and demonstrates that a molecular pathway controlling cell differentiation also defines material properties of extracellular matrix. Furthermore, our results suggest that the careful regulation of these properties is essential for healthy tissue functio
An Anti-Human ICAM-1 Antibody Inhibits Rhinovirus-Induced Exacerbations of Lung Inflammation
Human rhinoviruses (HRV) cause the majority of common colds and acute exacerbations of asthma and chronic obstructive pulmonary disease (COPD). Effective therapies are urgently needed, but no licensed treatments or vaccines currently exist. Of the 100 identified serotypes, ∼90% bind domain 1 of human intercellular adhesion molecule-1 (ICAM-1) as their cellular receptor, making this an attractive target for development of therapies; however, ICAM-1 domain 1 is also required for host defence and regulation of cell trafficking, principally via its major ligand LFA-1. Using a mouse anti-human ICAM-1 antibody (14C11) that specifically binds domain 1 of human ICAM-1, we show that 14C11 administered topically or systemically prevented entry of two major groups of rhinoviruses, HRV16 and HRV14, and reduced cellular inflammation, pro-inflammatory cytokine induction and virus load in vivo. 14C11 also reduced cellular inflammation and Th2 cytokine/chemokine production in a model of major group HRV-induced asthma exacerbation. Interestingly, 14C11 did not prevent cell adhesion via human ICAM-1/LFA-1 interactions in vitro, suggesting the epitope targeted by 14C11 was specific for viral entry. Thus a human ICAM-1 domain-1-specific antibody can prevent major group HRV entry and induction of airway inflammation in vivo
Midgut microbiota of the malaria mosquito vector Anopheles gambiae and Interactions with plasmodium falciparum Infection
The susceptibility of Anopheles mosquitoes to Plasmodium infections relies on complex interactions between the insect vector and the malaria parasite. A number of studies have shown that the mosquito innate immune responses play an important role in controlling the malaria infection and that the strength of parasite clearance is under genetic control, but little is known about the influence of environmental factors on the transmission success. We present here evidence that the composition of the vector gut microbiota is one of the major components that determine the outcome of mosquito infections. A. gambiae mosquitoes collected in natural breeding sites from Cameroon were experimentally challenged with a wild P. falciparum isolate, and their gut bacterial content was submitted for pyrosequencing analysis. The meta-taxogenomic approach revealed a broader richness of the midgut bacterial flora than previously described. Unexpectedly, the majority of bacterial species were found in only a small proportion of mosquitoes, and only 20 genera were shared by 80% of individuals. We show that observed differences in gut bacterial flora of adult mosquitoes is a result of breeding in distinct sites, suggesting that the native aquatic source where larvae were grown determines the composition of the midgut microbiota. Importantly, the abundance of Enterobacteriaceae in the mosquito midgut correlates significantly with the Plasmodium infection status. This striking relationship highlights the role of natural gut environment in parasite transmission. Deciphering microbe-pathogen interactions offers new perspectives to control disease transmission.Institut de Recherche pour le Developpement (IRD); French Agence Nationale pour la Recherche [ANR-11-BSV7-009-01]; European Community [242095, 223601]info:eu-repo/semantics/publishedVersio
Antenatal breast expression in women with diabetes: outcomes from a retrospective cohort study
Background: Women with diabetes are sometimes advised to express breast milk antenatally to prepare for
breastfeeding and to store colostrum for infant feeding in preventing or treating hypoglycaemia after the birth. The
acceptability, risks and benefits of this practice have not been evaluated. This was aimed to investigate the pattern
of antenatal breast expression uptake and its relationship with birth outcomes in women with diabetes.
Methods: This was part of a two year retrospective cohort study of pregnant women with diabetes (type 1, 2 and
gestational diabetes) who gave birth during 2001–2003 in Derby Hospitals NHS Foundation Trust (n = 94). The
information on the practice of antenatal breastfeeding expression and birth outcomes was collected via
self-administered questionnaires and by examining maternity records.
Results: Thirty-seven percent of women (35/94) recalled that they were advised to express antenatally and 17% did
(16/94). The mean gestational age at birth for women who hand-expressed was lower than that for those who did
not (mean difference (MD) (95% confidence intervals (CI)): -1.2 (−2.4 to 0.04), p = 0.06). A higher proportion of
babies from the antenatal expression group were admitted to special care baby units (SCBU) (MD (95% CI): 21%
(−3.9 to 46.3).
Conclusions: Less than half the women who stated that they were advised to express, did so. There seems to be
an indication that antenatal breast milk expression and lower gestational age at birth are associated. The trend of a higher rate of SCBU admission for babies from the breast milk expression group compared to those who did not
express antenatally is of concern. An appropriately-powered randomised controlled trial is needed to determine the
safety of this practice and its acceptability to women and health professionals before it can be recommended for
implementation in practice.
Keywords: Diabetes, Antenatal, Breast milk expression, Retrospective, Gestational age, Cohort, Gestation</p
Syntaxin 16 is a master recruitment factor for cytokinesis
Recently it was shown that both recycling endosome and endosomal sorting complex required for transport (ESCRT) components are required for cytokinesis, in which they are believed to act in a sequential manner to bring about secondary ingression and abscission, respectively. However, it is not clear how either of these complexes is targeted to the midbody and whether their delivery is coordinated. The trafficking of membrane vesicles between different intracellular organelles involves the formation of soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE) complexes. Although membrane traffic is known to play an important role in cytokinesis, the contribution and identity of intracellular SNAREs to cytokinesis remain unclear. Here we demonstrate that syntaxin 16 is a key regulator of cytokinesis, as it is required for recruitment of both recycling endosome–associated Exocyst and ESCRT machinery during late telophase, and therefore that these two distinct facets of cytokinesis are inextricably linked
Reframing as Reclamation: Trauma Theory, African Spiritualism, and Ecocriticism in Jesmyn Ward’s Sing, Unburied, Sing
This thesis explores how ecocriticism and trauma theory intersect within Jesmyn Ward’s novel Sing, Unburied, Sing (2017) to tackle the complex act of collective healing. Trauma, and its subset transgenerational trauma, have often been a focal point for critical analysis of other African American texts that engage with ghosts and hauntings, such as Toni Morrison’s Beloved (1987). Often, these ghosts are symbolic of transgenerational trauma in fictional works. While this association is apparent in Ward’s novel, this thesis applies the aforementioned modes of scholarship alongside African-based spiritualism to investigate further the inclusion of ghosts. To accomplish this approach, this thesis separates the analysis into two distinctly gendered sections: the first section unpacks the relationship between African-based spiritualism and female-centric conjure work in the family line, whereas the second section analyzes how trauma shapes black masculinity and how repression perpetuates transgenerational trauma. These two sections work together to prove how Ward’s novel engages with the transfer of trauma across generational lines and how she then offers a way to mend it at both an individual and collective level. As part of the discussion, I will be including critical work from scholars such as Kathleen Brogan, who clarifies between traumatic memory and narrative memory, as well as Gabriele Schwab, who observes transgenerational effects in both survivors and perpetrators of trauma. In the concluding section, I identify the way Ward navigates these interwoven parts in a world that continues to blend and create intersectional cultural identities
Effect of adding the novel fiber, PGX®, to commonly consumed foods on glycemic response, glycemic index and GRIP: a simple and effective strategy for reducing post prandial blood glucose levels - a randomized, controlled trial
<p>Abstract</p> <p>Background</p> <p>Reductions in postprandial glycemia have been demonstrated previously with the addition of the novel viscous polysaccharide (NVP), PolyGlycopleX<sup>® </sup>(PGX<sup>®</sup>), to an OGTT or white bread. This study explores whether these reductions are sustained when NVP is added to a range of commonly consumed foods or incorporated into a breakfast cereal.</p> <p>Methods</p> <p>Ten healthy subjects (4M, 6F; age 37.3 ± 3.6 y; BMI 23.8 ± 1.3 kg/m<sup>2</sup>), participated in an acute, randomized controlled trial. The glycemic response to cornflakes, rice, yogurt, and a frozen dinner with and without 5 g of NVP sprinkled onto the food was determined. In addition, 3 granolas with different levels of NVP and 3 control white breads and one white bread and milk were also consumed. All meals contained 50 g of available carbohydrate. Capillary blood samples were taken fasting and at 15, 30, 45, 60, 90 and 120 min after the start of the meal. The glycemic index (GI) and the glycemic reduction index potential (GRIP) were calculated. The blood glucose concentrations at each time and the iAUC values were subjected to repeated-measures analysis of variance (ANOVA) examining for the effect of test meal. After demonstration of significant heterogeneity, differences between individual means was assessed using GLM ANOVA with Tukey test to adjust for multiple comparisons.</p> <p>Results</p> <p>Addition of NVP reduced blood glucose response irrespective of food or dose (p < 0.01). The GI of cornflakes, cornflakes+NVP, rice, rice+NVP, yogurt, yogurt+NVP, turkey dinner, and turkey dinner+NVP were 83 ± 8, 58 ± 7, 82 ± 8, 45 ± 4, 44 ± 4, 38 ± 3, 55 ± 5 and 41 ± 4, respectively. The GI of the control granola, and granolas with 2.5 and 5 g of NVP were 64 ± 6, 33 ± 5, and 22 ± 3 respectively. GRIP was 6.8 ± 0.9 units per/g of NVP.</p> <p>Conclusion</p> <p>Sprinkling or incorporation of NVP into a variety of different foods is highly effective in reducing postprandial glycemia and lowering the GI of a food.</p> <p>Clinical Trial registration</p> <p>NCT00935350.</p
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