Unusual Rhythm Behind a Narrow Complex Tachycardia

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Nesting behaviour influences species-specific gas exchange across avian eggshells

Carefully controlled gas exchange across the eggshell is essential for the development of the avian embryo. Water vapour conductance (GH2O) across the shell, typically measured as mass loss during incubation, has been demonstrated to optimally ensure the healthy development of the embryo while avoiding desiccation. Accordingly, eggs exposed to sub-optimal gas exchange have reduced hatching success. We tested the association between eggshell GH2O and putative life-history correlates of adult birds, ecological nest parameters and physical characteristics of the egg itself to investigate how variation in GH2O has evolved to maintain optimal water loss across a diverse set of nest environments. We measured gas exchange through eggshell fragments in 151 British breeding bird species and fitted phylogenetically controlled, general linear models to test the relationship between GH2O and potential predictor parameters of each species. Of our 17 life-history traits, only two were retained in the final model: wet-incubating parent and nest type. Eggs of species where the parent habitually returned to the nest with wet plumage had significantly higher GH2O than those of parents that returned to the nest with dry plumage. Eggs of species nesting in ground burrows, cliffs and arboreal cups had significantly higher GH2O than those of species nesting on the ground in open nests or cups, in tree cavities and in shallow arboreal nests. Phylogenetic signal (measured as Pagel's λ) was intermediate in magnitude, suggesting that differences observed in the GH2O are dependent upon a combination of shared ancestry and species-specific life history and ecological traits. Although these data are correlational by nature, they are consistent with the hypothesis that parents constrained to return to the nest with wet plumage will increase the humidity of the nest environment, and the eggs of these species have evolved a higher GH2O to overcome this constraint and still achieve optimal water loss during incubation. We also suggest that eggs laid in cup nests and burrows may require a higher GH2O to overcome the increased humidity as a result from the confined nest microclimate lacking air movements through the nest. Taken together, these comparative data imply that species-specific levels of gas exchange across avian eggshells are variable and evolve in response to ecological and physical variation resulting from parental and nesting behaviours

Embrapa's evaluation and awards system: selected papers.

This paper presents basic conceptsw and operational aspects of Performance Evaluation system and Premiums fos outstanding resuilts irnplemented by Embrapa in 1996. This system aims to increase performance of research units, research teams and employess in gerenal, rewarding the more productive members of the institution. This system procedure for research units; e) team and individual empoyee evaluation; and, d) team and individual reward procedure. O presente trabalho apresenta conceitos e aspectos operacionais do Sistema de Avaliação e Premiação por Resultados da Embrapa, implantado em 1996. O sistema objetiva elevar o desempenho das unidades de pesquisa, das equipes e empregados da Empresa e recompensar os mais produtivos. O sistema e constituido por 4 componentes: a) avaliação de unidades; b) premiação de unidades; c) Avaliação de equipes e empregados; e d) premiação de equipes e empregados

Malaria Immunity in Man and Mosquito: Insights Into Unsolved Mysteries of a Deadly Infectious Disease

Malaria is a mosquito-borne disease caused by parasites of the obligate intracellular Apicomplexa family, the most deadly of which, Plasmodium falciparum, prevails in Africa. Malaria imposes a huge health burden on the world’s most vulnerable populations, claiming the lives of nearly a million children and pregnant women each year in Africa alone. Although there is keen interest in eradicating malaria, we do not yet have the necessary tools to meet this challenge, including an effective malaria vaccine and adequate vector control strategies. Here we review what is known about the mechanisms at play in immune resistance to malaria in both the human and mosquito hosts at each step in the parasite’s complex life cycle with a view towards developing the tools that will contribute to the prevention of disease and death and ultimately the goal of malaria eradication. In so doing we hope to inspire immunologists to participate in defeating this devastating disease

Cardiotoxicity in Breast Cancer Treatment: What About Left Ventricular Diastolic Function and Left Atrial Function?

Aims: Cardiotoxicity is a possible complication of cancer treatment, particularly with anthracyclines and anti-HER2 drugs. Systolic dysfunction has already been described. Diastolic dysfunction and left atrial function are less studied. We sought to analyze the impact of cardiotoxic treatments on left ventricular diastolic function and left atrial (LA) function. Methods and results: Retrospective study of 100 patients (all women, with a mean age of 54 ± 12 years) with three exams in the span of 1 year during treatment for breast cancer. Patients with previous cancer treatment, coronary artery disease, significant valvular disease, and atrial arrhythmias were excluded. Diastolic dysfunction was classified according to international guidelines and left atrial strain was analyzed by two-dimensional speckle tracking. In our sample, 74% received anthracyclines, 83% anti-HER2, and 76% radiation treatment. In the follow-up, 20% developed new or worsening diastolic dysfunction. Age was the only independent predictor (OR 1.93, 95% CI 1.04-3.58, P = .037). In left atrial function, only the contractile function was significantly reduced in 20.8% of the patients and age was also the only independent predictor, but with a protective effect (OR 0.51, 95% CI 0.28-0.91, P = .023). Conclusions: During breast cancer treatment, 20% of the patients develop new or worsening diastolic dysfunction, being age the main determinant, suggesting higher impact of chemotherapy in older patients. Contractile left atrial function is also compromised but, in this case, age seems to be protective. Our results support a stricter surveillance in older patients together to eventually adjust chemotherapy regimens.info:eu-repo/semantics/publishedVersio

Amplitude Damping for single-qubit System with single-qubit mixed-state Environment

We study a generalized amplitude damping channel when environment is initially in the single-qubit mixed state. Representing the affine transformation of the generalized amplitude damping by a three-dimensional volume, we plot explicitly the volume occupied by the channels simulatable by a single-qubit mixed-state environment. As expected, this volume is embedded in the total volume by the channels which is simulated by two-qubit enviroment. The volume ratio is approximately 0.08 which is much smaller than 3/8, the volume ratio for generalized depolarizing channels.Comment: 13 pages, 2 figures incluided V2: homepage address is included in reference V3: version to appear in J. Phys. A: Mathematical and Theoretica

Somatically Hypermutated Plasmodium-Specific IgM+ Memory B Cells Are Rapid, Plastic, Early Responders upon Malaria Rechallenge

SummaryHumoral immunity consists of pre-existing antibodies expressed by long-lived plasma cells and rapidly reactive memory B cells (MBC). Recent studies of MBC development and function after protein immunization have uncovered significant MBC heterogeneity. To clarify functional roles for distinct MBC subsets during malaria infection, we generated tetramers that identify Plasmodium-specific MBCs in both humans and mice. Long-lived murine Plasmodium-specific MBCs consisted of three populations: somatically hypermutated immunoglobulin M+ (IgM+) and IgG+ MBC subsets and an unmutated IgD+ MBC population. Rechallenge experiments revealed that high affinity, somatically hypermutated Plasmodium-specific IgM+ MBCs proliferated and gave rise to antibody-secreting cells that dominated the early secondary response to parasite rechallenge. IgM+ MBCs also gave rise to T cell-dependent IgM+ and IgG+B220+CD138+ plasmablasts or T cell-independent B220−CD138+ IgM+ plasma cells. Thus, even in competition with IgG+ MBCs, IgM+ MBCs are rapid, plastic, early responders to a secondary Plasmodium rechallenge and should be targeted by vaccine strategies

Measuring the activity of European and African Countries using Social Accounting Matrices

Economic models at the micro, meso and macro levels presuppose the existence of consistent databases that make it possible to quantify the activity of enterprises, sectors, regions, countries or continents. Such models can also be important aids in the policy decision process, since they permit the construction of scenarios resulting from the adoption of policy measures and the consequent changes that they introduce. When consistent with the United Nations System of National Accounts (SNA), the Social Accounting Matrix (SAM) can include all the nominal flows of the measured part of the economy, at the level of both production and the institutions, and therefore satisfies these requirements. Thus, in its numerical version, a SAM constitutes a database and provides a snapshot of the measured reality at a certain moment, whereas its possible algebraic versions, i.e. models that are based upon it, permit the construction of the above-mentioned scenarios. The possibility and usefulness of constructing SAMs for African countries consistent with the SNA will be examined and experimented. The SAM’s basic structure and consistency within the whole system will be studied, as well as any possible disaggregations, extensions, aggregates, indicators and balances that can be calculated. Other aspects beyond that basic structure will also be examined in order to show to what extent the SAM is capable of covering parts of the economy that are not covered by the SNA.info:eu-repo/semantics/publishedVersio