150 research outputs found
Understanding the Mechanisms of Biofouling on Nanofiltration Membranes: Effect of the Biofilm Structure on Solute Removal
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Considerações sobre a amêndoa da castanha de caju: aspectos nutricionais e de mercado.
Nesse artigo apresentam-se informações relacionadas à composição da amêndoa de castanha de caju (ACC), à essencialidade dos diferentes tipos de ácidos graxos, às necessidades humanas diárias desses componentes e à contribuição da ACC no seu suprimento. São analisadas a produção, a importação e a exportação mundial nos últimos 20 anos, assim como a participação da ACC no agronegócio brasileiro e sua comercialização. A análise estatística evidencia uma clara desvantagem no mercado internacional para o Brasil, que se mantém como terceiro exportador mundial de ACC, porém com taxas de crescimento bastante abaixo de seus principais competidores. Com relação à produção, também ocorre o mesmo, desvantagem para o Brasil, com um parco crescimento da produção de castanha de caju, quando comparado com seus principais competidores. Com relação ao aspecto nutricional, destacam-se a importância dos ácidos graxos (ômega 6 e 9) que compõem a ACC para a nutrição humana e as recomendações diárias de ácidos graxos nas diferentes fases do crescimento humano
Global compactness results for nonlocal problems
International audienceWe obtain a Struwe type global compactness result for a class of nonlinear nonlocal problems involving the fractional Laplacian operator and nonlinearities at critical growth
Long-term mortality in HIV patients virally suppressed for more than three years with incomplete CD4 recovery: A cohort study
<p>Abstract</p> <p>Background</p> <p>The mortality in patients with persistent low CD4 count despite several years of HAART with sustained viral suppression is poorly documented. We aimed to identify predictors for inadequate CD4 cell recovery and estimate mortality in patients with low CD4 count but otherwise successful HAART.</p> <p>Method</p> <p>In a nationwide cohort of HIV patients we identified all individuals who started HAART before 1 January 2005 with CD4 cell count ≤ 200 cells/μL and experienced three years with sustained viral suppression. Patients were categorized according to CD4 cell count after the three years suppressed period (≤ 200 cells/μL; immunological non-responders (INRs), >200 cells/μL; immunological responders (IRs)). We used logistic regression and Kaplan-Meier analysis to estimated risk factors and mortality for INRs compared to IRs.</p> <p>Results</p> <p>We identified 55 INRs and 236 IRs. In adjusted analysis age > 40 years and > one year from first CD4 cell count ≤ 200 cells/μL to start of the virologically suppressed period were associated with increased risk of INR. INRs had substantially higher mortality compared to IRs. The excess mortality was mainly seen in the INR group with > one year of immunological suppression prior to viral suppression and injection drug users (IDUs).</p> <p>Conclusion</p> <p>Age and prolonged periods of immune deficiency prior to successful HAART are risk factors for incomplete CD4 cell recovery. INRs have substantially increased long-term mortality mainly associated with prolonged immunological suppression prior to viral suppression and IDU.</p
Increased Bone Marrow Interleukin-7 (IL-7)/IL-7R Levels but Reduced IL-7 Responsiveness in HIV-Positive Patients Lacking CD4+ Gain on Antiviral Therapy
Background: The bone marrow (BM) cytokine milieu might substantially affect T-lymphocyte homeostasis in HIV-positive
individuals. Interleukin-7 (IL-7) is a bone marrow-derived cytokine regulating T-cell homeostasis through a CD4+-driven
feedback loop. CD4+ T-lymphopenia is associated with increased free IL-7 levels and reduced IL-7R expression/function,
which are only partially reverted by highly active antiretroviral therapy (HAART). We investigated the BM production,
peripheral expression and signaling (pStat5+ and Bcl-2+ CD4+/CD8+ T cells) of IL-7/IL-7Ra in 30 HAART-treated HIV-positive
patients who did not experience CD4+ recovery (CD4+ #200/ml) and who had different levels of HIV viremia; these patients
included 18 immunological nonresponders (INRs; HIV-RNA#50), 12 complete failures (CFs; HIV-RNA.1000), and 23 HIVseronegative
subjects.
Methods: We studied plasma IL-7 levels, IL-7Ra+CD4+/CD8+ T-cell proportions, IL-7Ra mRNA expression in PBMCs,
spontaneous IL-7 production by BM mononuclear cells (BMMCs), and IL-7 mRNA/IL-7Ra mRNA in BMMC-derived stromal cells
(SCs). We also studied T-cell responsiveness to IL-7 by measuring the proportions of pStat5+ and Bcl-2+ CD4+/CD8+ T cells.
Results: Compared to HIV-seronegative controls, CFs and INRs presented elevated plasma IL-7 levels and lower IL-7Ra
CD4+/CD8+ cell-surface expression and peripheral blood production, confirming the most relevant IL-7/IL-7R disruption.
Interestingly, BM investigation revealed a trend of higher spontaneous IL-7 production in INRs (p = .09 vs. CFs) with a
nonsignificant trend toward higher IL-7-Ra mRNA levels in BMMC-derived stromal cells. However, upon IL-7 stimulation, the
proportion of pStat5+CD4+ T cells did not increase in INRs despite higher constitutive levels (p = .06); INRs also displayed
lower Bcl-2+CD8+ T-cell proportions than controls (p = .04).
Conclusions: Despite severe CD4+ T-lymphopenia and a disrupted IL-7/IL-7R profile in the periphery, INRs display elevated
BM IL-7/IL-7Ra expression but impaired T-cell responsiveness to IL-7, suggesting the activity of a central compensatory
pathway targeted to replenish the CD4+ compartment, which is nevertheless inappropriate to compensate the
dysfunctional signaling through IL-7 receptor
Incident Tuberculosis during Antiretroviral Therapy Contributes to Suboptimal Immune Reconstitution in a Large Urban HIV Clinic in Sub-Saharan Africa
Antiretroviral therapy (ART) effectively decreases tuberculosis (TB) incidence long-term, but is associated with high TB incidence rates in the first 6 months. We sought to determine the incidence and the long-term effects of TB during ART on HIV treatment outcome, and the risk factors for incident TB during ART in a large urban HIV clinic in Uganda.Routinely collected longitudinal clinical data from all patients initiated on first-line ART was retrospectively analysed. 5,982 patients were included with a median baseline CD4+ T cell count (CD4 count) of 117 cells/mm(3) (interquartile range [IQR]; 42, 182). In the first 2 years, there were 336 (5.6%) incident TB events in 10,710 person-years (py) of follow-up (3.14 cases/100 pyar [95% CI 2.82-3.49]); incidence rates at 0-3, 3-6, 6-12 and 12-24 months were 11.25 (9.58-13.21), 6.27 (4.99-7.87), 2.47 (1.87-3.36) and 1.02 (0.80-1.31), respectively. Incident TB during ART was independently associated with baseline CD4 count of <50 cells/mm(3) (hazard ratio [HR] 1.84 [1.25-2.70], P = 0.002) and male gender (HR 1.68 [1.34-2.11], P<0.001). After two years on ART, the patients who had developed TB in the first 12 months had a significantly lower median CD4 count increase (184 cells/mm(3) [IQR; 107, 258, n = 118] vs 209 cells/mm(3) [124, 309, n = 2166], P = 0.01), a larger proportion of suboptimal immune reconstitution according to two definitions (increase in CD4 count <200 cells/mm(3): 57.4% vs 46.9%, P = 0.03, and absolute CD4 count <200 cells/mm(3): 30.4 vs 19.9%, P = 0.006), and a higher percentage of immunological failure according to the WHO criteria (13.6% vs 6.5%, P = 0.003). Incident TB during ART was independently associated with poor CD4 count recovery and fulfilling WHO immunological failure definitions.Incident TB during ART occurs most often within 3 months and in patients with CD4 counts less than 50 cells/mm(3). Incident TB during ART is associated with long-term impairment in immune recovery
On the Imitation of Goal Directed Movements of a Humanoid Robot
Interacting with a social robot should give people a better understanding of the robot’s actions and intentions. In terms of human–human interaction (HHI), people can interpret actions of others in an effortless way. However, it is still unclear whether people can do the same with humanoid robots. Imitation (of the robot’s actions) provides us with an intuitive means for solving this puzzle, because it is closely related to interpreting another’s actions. In the study of human imitation, the theory of goal-directed imitation holds that the imitator tends to imitate the action goals whenever the action goals are salient, otherwise people tend to imitate the action means. We investigated this theory for human robot interaction by manipulating the presence and absence of the goal object when people imitate the robot’s pointing gestures. The results showed that the presence of a goal object reduces people’s goal errors. Moreover, we found that most people tend to match their action means rather than the goals of the robot’s action. To ensure that participants considered the robot as a social agent, we designed a natural interaction task where the turn-taking cue was included: we let the robot look at the human after completing the pointing gesture at varying latencies. As expected, we found that the earlier the robot gazes at people, the shorter the reaction time of people was to start to imitate. Our results show that people are responsive to a robot’s social gaze cues, and that they are responsive to the action goals of robots, although not as much as in HHI
Developmental perspectives on interpersonal affective touch
In the last decade, philosophy, neuroscience and psychology alike have paid increasing attention to the study of interpersonal affective touch, which refers to the emotional and motivational facets of tactile sensation. Some aspects of affective touch have been linked to a neurophysiologically specialised system, namely the C tactile (CT) system. While the role of this sys-tem for affiliation, social bonding and communication of emotions have been widely investigated, only recently researchers have started to focus on the potential role of interpersonal affective touch in acquiring awareness of the body as our own, i.e. as belonging to our psychological ‘self’. We review and discuss recent developmental and adult findings, pointing to the central role of interpersonal affective touch in body awareness and social cognition in health and disorders. We propose that interpersonal affective touch, as an interoceptive modality invested of a social nature, can uniquely contribute to the ongoing debate in philosophy about the primacy of the relational nature of the minimal self
Original Article
The pancreas taken from the frog (Rana nigromaculata) was fixed in 1% OsO_4 and sliced into ultrathin sections for electron microscopic studies. The following observations were made: 1. A great \u27number of minute granules found in the cytoplasm of a pancreatic cell were called the microsomes, which were divided into two types, the C-microsome and S-microsome. 2. Electron microsopic studies of the ergastoplasm showed that it is composed of the microsome granules and A-substance. The microsomes were seen embedded in the A-substance which was either filamentous or membranous. The membranous structure, which was called the Am-membrane, was seen to form a sac, with a cavity of varying sizes, or to form a lamella. 3. The Am-membrane has close similarity to α-cytomembrane of Sjostrand, except that the latter is rough-surfaced. It was deduced that the Am-membrane, which is smooth-surfaced, might turn into the rough-surfaced α-cytomembrane. 4. There was the Golgi apparatus in the supranuclear region of a pancreatic cell. It consisted of the Golgi membrane, Golgi vacuole and. Golgi vesicle. 5. The mitochondria of a pancreatic cell appeared like long filaments, and some of them were seen to ramify. 6. The membrane of mitochondria, i. e. the limiting membrane, consisted of the Ammembrane. The mitochondria contained a lot of A-substances, as well as the C-microsomes and S-microsomes. When the mitochondria came into being, there appeared inside them chains of granules, which appeared like strips of beads, as the outgrowths of the A-substance and the microsome granules attached to the Am-membrane. They are the so-called cristae mitochondriales. 7. The secretory granules originate in the microsomes. They came into being when the microsomes gradually thickened and grew in size as various substances became adhered to them. Some of the secretory granules were covered with a membrane and appeared like what they have called the intracisternal granule of Palade.It seemed that this was a phenomenon attendant upon the dissolution and liqutefaction of the secretory granule. 8. Comparative studies were made of the ergastoplasm of the pancreatic cells from the frogs in hibernation, the frogs artificially hungered, the frogs which were given food after a certain period of fasting, the frogs to which pilocarpine was given subcutaneously, and the very young, immature frogs. The studies revealed that the ergastoplasm of the pancreatic cells greatly varied in form with the difference in nutritive condition and with different developmental stages of the cell. The change in form and structure occured as a result of transformation of the microsomes and A-substance. The ergastoplasm, even after it has come into being, might easily be inactivated if nutrition is defective. The ergastoplasm is concerned in the secretory mechanism, which is different from the secretory phenomenon of the secretory granules. It would seem that structurally the mitochondria have no direct relation to this mechanism
Mycobacterium tuberculosis complex genetic diversity: mining the fourth international spoligotyping database (SpolDB4) for classification, population genetics and epidemiology
BACKGROUND: The Direct Repeat locus of the Mycobacterium tuberculosis complex (MTC) is a member of the CRISPR (Clustered regularly interspaced short palindromic repeats) sequences family. Spoligotyping is the widely used PCR-based reverse-hybridization blotting technique that assays the genetic diversity of this locus and is useful both for clinical laboratory, molecular epidemiology, evolutionary and population genetics. It is easy, robust, cheap, and produces highly diverse portable numerical results, as the result of the combination of (1) Unique Events Polymorphism (UEP) (2) Insertion-Sequence-mediated genetic recombination. Genetic convergence, although rare, was also previously demonstrated. Three previous international spoligotype databases had partly revealed the global and local geographical structures of MTC bacilli populations, however, there was a need for the release of a new, more representative and extended, international spoligotyping database. RESULTS: The fourth international spoligotyping database, SpolDB4, describes 1939 shared-types (STs) representative of a total of 39,295 strains from 122 countries, which are tentatively classified into 62 clades/lineages using a mixed expert-based and bioinformatical approach. The SpolDB4 update adds 26 new potentially phylogeographically-specific MTC genotype families. It provides a clearer picture of the current MTC genomes diversity as well as on the relationships between the genetic attributes investigated (spoligotypes) and the infra-species classification and evolutionary history of the species. Indeed, an independent Naïve-Bayes mixture-model analysis has validated main of the previous supervised SpolDB3 classification results, confirming the usefulness of both supervised and unsupervised models as an approach to understand MTC population structure. Updated results on the epidemiological status of spoligotypes, as well as genetic prevalence maps on six main lineages are also shown. Our results suggests the existence of fine geographical genetic clines within MTC populations, that could mirror the passed and present Homo sapiens sapiens demographical and mycobacterial co-evolutionary history whose structure could be further reconstructed and modelled, thereby providing a large-scale conceptual framework of the global TB Epidemiologic Network. CONCLUSION: Our results broaden the knowledge of the global phylogeography of the MTC complex. SpolDB4 should be a very useful tool to better define the identity of a given MTC clinical isolate, and to better analyze the links between its current spreading and previous evolutionary history. The building and mining of extended MTC polymorphic genetic databases is in progress
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