4,799 research outputs found
Longest Common Extensions in Sublinear Space
The longest common extension problem (LCE problem) is to construct a data
structure for an input string of length that supports LCE
queries. Such a query returns the length of the longest common prefix of the
suffixes starting at positions and in . This classic problem has a
well-known solution that uses space and query time. In this paper
we show that for any trade-off parameter , the problem can
be solved in space and query time. This
significantly improves the previously best known time-space trade-offs, and
almost matches the best known time-space product lower bound.Comment: An extended abstract of this paper has been accepted to CPM 201
Structure-Based Identification and Characterization of Inhibitors of the Epilepsy-Associated KNa1.1 (KCNT1) Potassium Channel
Drug-resistant epileptic encephalopathies of infancy have been associated with KCNT1 gainof-function mutations, which increase the activity of KNa1.1 sodium-activated potassium channels. Pharmacological inhibition of hyperactive KNa1.1 channels by quinidine has been proposed as a stratified treatment, but mostly this has not been successful, being linked to the low potency and lack of specificity of the drug. Here we describe the use of a previously determined cryo-electron microscopy-derived KNa1.1 structure and mutational analysis to identify how quinidine binds to the channel pore and, using computational methods, screened for compounds predicated to bind to this site. We describe six compounds that inhibited KNa1.1 channels with low- and sub-micromolar potencies, likely also through binding in the intracellular pore vestibule. In hERG inhibition and cytotoxicity assays, two compounds were ineffective. These may provide starting points for the development of new pharmacophores and could become tool compounds to study this channel further
Subregional hippocampal morphology and psychiatric outcome in adolescents who were born very preterm and at term
Background: The hippocampus has been reported to be structurally and functionally altered as a sequel of very preterm birth ( < 33 weeks gestation), possibly due its vulnerability to hypoxic-ischemic damage in the neonatal period. We examined hippocampal volumes and subregional morphology in very preterm born individuals in mid- and late adolescence and their association with psychiatric outcome. Methods: Structural brain magnetic resonance images were acquired at two time points (baseline and follow-up) from 65 ex-preterm adolescents (mean age = 15.5 and 19.6 years) and 36 termborn controls (mean age=15.0 and 19.0 years). Hippocampal volumes and subregional morphometric differences were measured from manual tracings and with three-dimensional shape analysis. Psychiatric outcome was assessed with the Rutter Parents' Scale at baseline, the General Health Questionnaire at follow-up and the Peters Delusional Inventory at both time points. Results: In contrast to previous studies we did not find significant difference in the cross-sectional or longitudinal hippocampal volumes between individuals born preterm and controls, despite preterm individual having significantly smaller whole brain volumes. Shape analysis at baseline revealed subregional deformations in 28% of total bilateral hippocampal surface, reflecting atrophy, in ex-preterm individuals compared to controls, and in 22% at follow-up. In ex-preterm individuals, longitudinal changes in hippocampal shape accounted for 11% of the total surface, while in controls they reached 20%. In the whole sample (both groups) larger right hippocampal volume and bilateral anterior surface deformations at baseline were associated with delusional ideation scores at follow-up. Conclusions: This study suggests a dynamic association between cross-sectional hippocampal volumes, longitudinal changes and surface deformations and psychosis proneness. Copyright
Short-term outcomes of pubertal suppression in a selected cohort of 12 to 15 year old young people with persistent gender dysphoria in the UK
BACKGROUND: In adolescents with severe and persistent gender dysphoria (GD), gonadotropin releasing hormone analogues (GnRHa) are used from early/middle puberty with the aim of delaying irreversible and unwanted pubertal body changes. Evidence of outcomes of pubertal suppression in GD is limited. METHODS: We undertook an uncontrolled prospective observational study of GnRHa as monotherapy in 44 12-15 year olds with persistent and severe GD. Prespecified analyses were limited to key outcomes: bone mineral content (BMC) and bone mineral density (BMD); Child Behaviour CheckList (CBCL) total t-score; Youth Self-Report (YSR) total t-score; CBCL and YSR self-harm indices; at 12, 24 and 36 months. Semistructured interviews were conducted on GnRHa. RESULTS: 44 patients had data at 12 months follow-up, 24 at 24 months and 14 at 36 months. All had normal karyotype and endocrinology consistent with birth-registered sex. All achieved suppression of gonadotropins by 6 months. At the end of the study one ceased GnRHa and 43 (98%) elected to start cross-sex hormones. There was no change from baseline in spine BMD at 12 months nor in hip BMD at 24 and 36 months, but at 24 months lumbar spine BMC and BMD were higher than at baseline (BMC +6.0 (95% CI: 4.0, 7.9); BMD +0.05 (0.03, 0.07)). There were no changes from baseline to 12 or 24 months in CBCL or YSR total t-scores or for CBCL or YSR self-harm indices, nor for CBCL total t-score or self-harm index at 36 months. Most participants reported positive or a mixture of positive and negative life changes on GnRHa. Anticipated adverse events were common. CONCLUSIONS: Overall patient experience of changes on GnRHa treatment was positive. We identified no changes in psychological function. Changes in BMD were consistent with suppression of growth. Larger and longer-term prospective studies using a range of designs are needed to more fully quantify the benefits and harms of pubertal suppression in GD
A new purple sulfur bacterium from saline littoral sediments, Thiorhodotvibrio winogradskyi gen. nov. and sp. nov.
Two strains of a new purple sulfur bacterium were isolated in pure culture from the littoral sediment of a saline lake (Mahoney Lake, Canada) and a marine microbial mat from the North Sea island of Mellum, respectively. Single cells were vibrioid-to spirilloid-shaped and motile by means of single polar flagella. Intracellular photosynthetic membranes were of the vesicular type. As photosynthetic pigments, bacteriochlorophyll a and the carotenoids lycopene, rhodopin, anhydrorhodovibrin, rhodovibrin and spirilloxanthin were present.
Hydrogen sulfide and elemental sulfur were used under anoxic conditions for phototrophic growth. In addition one strain (06511) used thiosulfate. Carbon dioxide, acetate and pyruvate were utilized by both strains as carbon sources. Depending on the strain propionate, succinate, fumarate, malate, tartrate, malonate, glycerol or peptone may additionally serve as carbon sources in the light. Optimum growth rates were obtained at pH 7.2, 33 °C, 50 mol m-2 s-1 intensity of daylight fluorescent tubes and a salinity of 2.2–3.2% NaCl. During growth on sulfide, up to ten small sulfur globules were formed inside the cells. The strains grew microaerophilic in the dark and exhibited high specific respiration rates. No vitamins were required for growth. The DNA base composition was 61.0–62.4 mol% G+C.
The newly isolated bacterium belongs to the family chromatiaceae and is described as a member of a new genus and species, Thiorhodovibrio winogradskyi gen. nov. and sp. nov. with the type strain SSP1, DSM No. 6702
Lead Exposure Is Associated with Decreased Serum Paraoxonase 1 (PON1) Activity and Genotypes
Lead exposure causes cardiac and vascular damage in experimental animals. However, there is considerable debate regarding the causal relationship between lead exposure and cardiovascular dysfunction in humans. Paraoxonase 1 (PON1), a high-density lipoprotein-associated antioxidant enzyme, is capable of hydrolyzing oxidized lipids and thus protects against atherosclerosis. Previous studies have shown that lead and several other metal ions are able to inhibit PON1 activity in vitro. To investigate whether lead exposure has influence on serum PON1 activity, we conducted a cross-sectional study of workers from a lead battery manufactory and lead recycling plant. Blood samples were analyzed for whole-blood lead levels, serum PON1 activity, and three common PON1 polymorphisms (Q192R, L55M, −108C/T). The mean blood lead level (± SD) of this cohort was 27.1 ± 15 μg/dL. Multiple linear regression analysis showed that blood lead levels were significantly associated with decreased serum PON1 activity (p < 0.001) in lead workers. This negative correlation was more evident for workers who carry the R192 allele, which has been suggested to be a risk factor for coronary heart disease. Taken together, our results suggest that the decrease in serum PON1 activity due to lead exposure may render individuals more susceptible to atherosclerosis, particularly subjects who are homozygous for the R192 allele
Children grow and horses race: is the adiposity rebound a critical period for later obesity?
BACKGROUND: The adiposity rebound is the second rise in body mass index that occurs between 3 and 7 years. An early age at adiposity rebound is known to be a risk factor for later obesity. The aim here is to clarify the connection between the age at rebound and the corresponding pattern of body mass index change, in centile terms, so as to better understand its ability to predict later fatness. DISCUSSION: Longitudinal changes in body mass index during adiposity rebound, measured both in original (kg/m(2)) and standard deviation (SD) score units, are studied in five hypothetical subjects. Two aspects of the body mass index curve, the body mass index centile and the rate of body mass index centile crossing, determine a child's age at rebound. A high centile and upward centile crossing are both associated separately with an early rebound, while a low centile and/or downward centile crossing correspond to a late rebound. Early adiposity rebound is a risk factor for later fatness because it identifies children whose body mass index centile is high and/or crossing upwards. Such children are likely to have a raised body mass index later in childhood and adulthood. This is an example of Peto's "horse racing effect". The association of centile crossing with later obesity is statistical not physiological, and it applies at all ages not just at rebound, so adiposity rebound cannot be considered a critical period for future obesity. Body mass index centile crossing is a more direct indicator of the underlying drive to fatness. SUMMARY: An early age at adiposity rebound predicts later fatness because it identifies children whose body mass index centile is high and/or crossing upwards. Such children are likely to have a raised body mass index later. Body mass index centile crossing is more direct than the timing of adiposity rebound for predicting later fatness
Envolvimento de "stakeholders" em direcção à construção sustentável
A mudança de paradigma requerida para evoluir na direcção da construção sustentável exige a conjugação efectiva de diferentes condições determinantes, que inclui a percepção, comportamento e envolvimento de partes em todo o processo, em particular os actores que efectam, bem como aqueles que são afectados pela tomada de decisão. Para além das formas convencionais de envolvimento dos stokholders, novas formas de cooperação precisam de ser exploradas. O presente artigo tem por obectivo reflectir sobre a melhor estratégia de gestão a aplicar nos actores-chave num contexto de networking sobre construção sustentável em Portugal. A análise efectuada permitiu verificar que o sucesso de uma plataforma de cooperação está condicionada pela participação dos actores-chave, pelo que há necessidade de fazer o mapeamento, a hierarquização e a definição de uma estratégia de gestão que maximize asua cooperação, isto é, que vá ao encontro das necessidades de cada um deles, para que a plataforma de cooperação se torne um efectivo espaço de partilha, diálogo, aprendizagem e inovação
Effect of disease-modifying agents and their association with mortality in multi-morbid patients with heart failure with reduced ejection fraction
Aims
An increasing proportion of patients with heart failure with reduced ejection fraction (HFrEF) have co‐morbidities. The effect of these co‐morbidities on modes of death and the effect of disease‐modifying agents in multi‐morbid patients is unknown.
Methods and results
We performed a prospective cohort study of ambulatory patients with HFrEF to assess predictors of outcomes. We identified four key co‐morbidities—ischaemic aetiology of heart failure, diabetes mellitus, chronic obstructive pulmonary disease (COPD), and chronic kidney disease (CKD)—that were highly prevalent and associated with an increased risk of all‐cause mortality. We used these data to explore modes of death and the utilization of disease‐modifying agents in patients with and without these co‐morbidities. The cohort included 1789 consecutively recruited patients who had an average age of 69.6 ± 12.5 years, and 1307 (73%) were male. Ischaemic aetiology of heart failure was the most common co‐morbidity, occurring in 1061 (59%) patients; 503 (28%) patients had diabetes mellitus, 283 (16%) had COPD, and 140 (8%) had CKD stage IV/V. During mean follow‐up of 3.8 ± 1.6 years, 737 (41.5%) patients died, classified as progressive heart failure (n = 227, 32%), sudden (n = 112, 16%), and non‐cardiovascular deaths (n = 314, 44%). Multi‐morbid patients were older (P 2.5‐fold and 1.5‐fold increased risk of sudden death, whilst higher doses of beta‐adrenoceptor antagonists were protective (hazard ratio per milligram 0.92, 95% confidence interval 0.86–0.98, P = 0.009). Each milligram of bisoprolol‐equivalent beta‐adrenoceptor antagonist was associated with 9% (P = 0.001) and 11% (P = 0.023) reduction of sudden deaths in patients with <2 and ≥2 co‐morbidities, respectively.
Conclusions
Higher doses of beta‐adrenoceptor antagonist are associated with greater protection from sudden death, most evident in multi‐morbid patients. Patients with COPD who appear to be at the highest risk of sudden death are prescribed the lowest doses and less likely to be implanted with implantable cardioverter defibrillators, which might represent a missed opportunity to optimize safe and proven therapies for these patients
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