406 research outputs found
An in vivo control map for the eukaryotic mRNA translation machinery
Rate control analysis defines the in vivo control map governing yeast protein synthesis and generates an extensively parameterized digital model of the translation pathway. Among other non-intuitive outcomes, translation demonstrates a high degree of functional modularity and comprises a non-stoichiometric combination of proteins manifesting functional convergence on a shared maximal translation rate. In exponentially growing cells, polypeptide elongation (eEF1A, eEF2, and eEF3) exerts the strongest control. The two other strong control points are recruitment of mRNA and tRNAi to the 40S ribosomal subunit (eIF4F and eIF2) and termination (eRF1; Dbp5). In contrast, factors that are found to promote mRNA scanning efficiency on a longer than-average 5′untranslated region (eIF1, eIF1A, Ded1, eIF2B, eIF3, and eIF5) exceed the levels required for maximal control. This is expected to allow the cell to minimize scanning transition times, particularly for longer 5′UTRs. The analysis reveals these and other collective adaptations of control shared across the factors, as well as features that reflect functional modularity and system robustness. Remarkably, gene duplication is implicated in the fine control of cellular protein synthesis
Psychometric analysis of the scale for the predisposition to the occurrence of adverse events in nursing care provided in ICUS
OBJECTIVE: to present the result of the validity and reliability studies concerning the Scale for the Predisposition to the Occurrence of Adverse Events (EPEA).
METHOD: construct validity was based on Principal Components Analysis.
RESULTS: reliability verified through Cronbach's alpha indicated good reliability (structure α=0.80; process α=0.92).
CONCLUSION: based on its psychometric indicators, the EPEA can be considered a valid measure to assess the attitudes of nurses in relation to factors that potentially lead to the occurrence of adverse events in ICUs
Advancing Tests of Relativistic Gravity via Laser Ranging to Phobos
Phobos Laser Ranging (PLR) is a concept for a space mission designed to
advance tests of relativistic gravity in the solar system. PLR's primary
objective is to measure the curvature of space around the Sun, represented by
the Eddington parameter , with an accuracy of two parts in ,
thereby improving today's best result by two orders of magnitude. Other mission
goals include measurements of the time-rate-of-change of the gravitational
constant, and of the gravitational inverse square law at 1.5 AU
distances--with up to two orders-of-magnitude improvement for each. The science
parameters will be estimated using laser ranging measurements of the distance
between an Earth station and an active laser transponder on Phobos capable of
reaching mm-level range resolution. A transponder on Phobos sending 0.25 mJ, 10
ps pulses at 1 kHz, and receiving asynchronous 1 kHz pulses from earth via a 12
cm aperture will permit links that even at maximum range will exceed a photon
per second. A total measurement precision of 50 ps demands a few hundred
photons to average to 1 mm (3.3 ps) range precision. Existing satellite laser
ranging (SLR) facilities--with appropriate augmentation--may be able to
participate in PLR. Since Phobos' orbital period is about 8 hours, each
observatory is guaranteed visibility of the Phobos instrument every Earth day.
Given the current technology readiness level, PLR could be started in 2011 for
launch in 2016 for 3 years of science operations. We discuss the PLR's science
objectives, instrument, and mission design. We also present the details of
science simulations performed to support the mission's primary objectives.Comment: 25 pages, 10 figures, 9 table
SEROLOGIC SURVEY ON HANTAVIRUS IN BLOOD DONORS FROM THE STATE OF SANTA CATARINA, BRAZIL
The Pioneer Anomaly
Radio-metric Doppler tracking data received from the Pioneer 10 and 11
spacecraft from heliocentric distances of 20-70 AU has consistently indicated
the presence of a small, anomalous, blue-shifted frequency drift uniformly
changing with a rate of ~6 x 10^{-9} Hz/s. Ultimately, the drift was
interpreted as a constant sunward deceleration of each particular spacecraft at
the level of a_P = (8.74 +/- 1.33) x 10^{-10} m/s^2. This apparent violation of
the Newton's gravitational inverse-square law has become known as the Pioneer
anomaly; the nature of this anomaly remains unexplained. In this review, we
summarize the current knowledge of the physical properties of the anomaly and
the conditions that led to its detection and characterization. We review
various mechanisms proposed to explain the anomaly and discuss the current
state of efforts to determine its nature. A comprehensive new investigation of
the anomalous behavior of the two Pioneers has begun recently. The new efforts
rely on the much-extended set of radio-metric Doppler data for both spacecraft
in conjunction with the newly available complete record of their telemetry
files and a large archive of original project documentation. As the new study
is yet to report its findings, this review provides the necessary background
for the new results to appear in the near future. In particular, we provide a
significant amount of information on the design, operations and behavior of the
two Pioneers during their entire missions, including descriptions of various
data formats and techniques used for their navigation and radio-science data
analysis. As most of this information was recovered relatively recently, it was
not used in the previous studies of the Pioneer anomaly, but it is critical for
the new investigation.Comment: 165 pages, 40 figures, 16 tables; accepted for publication in Living
Reviews in Relativit
Cytogenetic divergence in two sympatric fish species of the genus Astyanax Baird and Girard, 1854 (Characiformes, Characidae) from northeastern Brazil
Relationship between functional fitness, medication costs and mood in elderly people
Objective: to verify if functional fitness (FF) is associated with the annual cost of medication consumption and mood states (MSt) in elderly people. Methods: a cross-sectional study with 229 elderly people aged 65 years or more at Santa Casa de Misericórdia de Coimbra, Portugal. Seniors with physical and psychological limitations were excluded, as well as those using medication that limits performance on the tests. The Senior Fitness Test was used to evaluate FF, and the Profile of Mood States - Short Form to evaluate the MSt. The statistical analysis was based on Mancova, with adjustment for age, for comparison between men and women, and adjustment for sex, for comparison between cardiorespiratory fitness quintiles. The association between the variables under study was made with partial correlation, controlling for the effects of age, sex and body mass index. Results: an inverse correlation between cardiorespiratory fitness and the annual cost of medication consumption was found (p < 0.01). FF is also inversely associated with MSt (p < 0.05). Comparisons between cardiorespiratory fitness quintiles showed higher medication consumption costs in seniors with lower aerobic endurance, as well as higher deterioration in MSt (p < 0.01). Conclusion: elderly people with better FF and, specifically, better cardiorespiratory fitness present lower medication consumption costs and a more positive MSt
Management of congestive heart failure: a gender gap may still exist. Observations from a contemporary cohort
BACKGROUND: Unlike other cardiovascular diseases the incidence and prevalence of congestive heart failure (CHF) continues to increase. While gender differences in coronary artery disease have been well described, to date, there has been a relative paucity of similar data in patients with CHF. We conducted a pilot study to evaluate the profile and management of patients with CHF at a tertiary care centre to determine if a gender difference exists. METHODS: A chart review was performed at a tertiary care centre on consecutive patients admitted with a primary diagnosis of CHF between June 1997 and 1998. Co-morbidity, diagnostic investigations, and management of CHF were recorded. Comparisons between male and female patients were conducted. RESULTS: One hundred and forty five patients were reviewed. There were 80 male (M) and 65 female (F) patients of similar age [71.6 vs. 71.3 (M vs. F), p = NS]. Male patients were more likely to have had a previous myocardial infarction (66% vs. 35%, p < 0.01) and revascularization (41% vs. 20%, p < 0.05), and had worse left ventricular ejection fraction (LVEF) than women, [median LVEF 3 vs. 2 (M vs. F), p < 0.01]. Male patients were more likely to have a non-invasive assessment of left ventricular (LV) function [85% vs. 69%, (M vs. F), p < 0.05]. A logistic regression analysis suggests that amongst those without coronary disease, males were more likely to receive non-invasive testing. There were no differences in the use of prescribed medications, in this cohort. CONCLUSIONS: This pilot study demonstrated that there seem to be important gender differences in the profile and management of patients with CHF. Importantly women were less likely to have an evaluation of LV function. As assessment of LV function has significant implications on patient management, this data justifies the need for larger studies to assess gender differences in CHF profile and treatment
Cytogenetic analysis of Astylus antis (Perty, 1830) (Coleoptera, Melyridae): Karyotype, heterochromatin and location of ribosomal genes
Cytogenetic analysis of Astylus antis using mitotic and meiotic cells was performed to characterize the haploid and diploid numbers, sex determination system, chromosome morphology, constitutive heterochromatin distribution pattern and chromosomes carrying nucleolus organizer regions (NORs). Analysis of spermatogonial metaphase cells revealed the diploid number 2n = 18, with mostly metacentric chromosomes. Metaphase I cells exhibited 2n = 8II+Xyp and a parachute configuration of the sex chromosomes. Spermatogonial metaphase cells submitted to C-banding showed the presence of small dots of constitutive heterochromatin in the centromeric regions of nearly all the autosomes and on the short arm of the X chromosome (Xp), as well as an additional band on one of the arms of pair 1. Mitotic cells submitted to double staining with base-specific fluorochromes (DAPI-CMA3 ) revealed no regions rich in A+T or G+C sequences. Analysis of spermatogonial mitotic cells after sequential Giemsa/AgNO 3 staining did not reveal any specific mark on the chromosomes. Meiotic metaphase I cells stained with silver nitrate revealed a strong impregnation associated to the sex chromosomes, and in situ hybridization with an 18S rDNA probe showed ribosomal cistrons in an autosomal bivalent
Etiopathogenesis of type 1 diabetes mellitus: prognostic factors for the evolution of residual β cell function
Type 1A diabetes mellitus (T1ADM) is a progressive autoimmune disease mediated by T lymphocytes with destruction of beta cells. Up to now, we do not have precise methods to assess the beta cell mass, "in vivo" or "ex-vivo". The studies about its genetic susceptibility show strong association with class II antigens of the HLA system (particularly DQ). Others genetics associations are weaker and depend on the population studied. A combination of precipitating events may occur at the beginning of the disease. There is a silent loss of immune-mediated beta cells mass which velocity has an inverse relation with the age, but it is influenced by genetic and metabolic factors. We can predict the development of the disease primarily through the determination of four biochemically islet auto antibodies against antigens like insulin, GAD65, IA2 and Znt8. Beta cell destruction is chronically progressive but at clinical diagnosis of the disease a reserve of these cells still functioning. The goal of secondary disease prevention is halt the autoimmune attack on beta cells by redirecting or dampening the immune system. It is remains one of the foremost therapeutic goals in the T1ADM. Glycemic intensive control and immunotherapeutic agents may preserve beta-cell function in newly diagnosed patients with T1ADM. It may be assessed through C-peptide values, which are important for glycemic stability and for the prevention of chronic complications of this disease. This article will summarize the etiopathogenesis mechanisms of this disease and the factors can influence on residual C-peptide and the strategies to it preservation
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