Children's questions may reveal a great deal about the characteristics of objects they consider to be conceptually important. Thirty-two preschool children were given opportunities to ask questions about unfamiliar artifacts and animals. The children asked ambiguous questions such as "What is it?" about artifacts and animals alike.
View Article and Find Full Text PDFWe describe a novel algorithm that includes the effect of host lattice flexibility into molecular dynamics simulations that use rigid lattices. It uses a Lowe-Andersen thermostat for interface-fluid collisions to take the most important aspects of flexibility into account. The same diffusivities and other properties of the flexible framework system are reproduced at a small fraction of the computational cost of an explicit simulation.
View Article and Find Full Text PDFMirror neurons, located in the premotor cortex of macaque monkeys, are activated both by the performance and the passive observation of particular goal-directed actions. Although this property would seem to make them the ideal neural substrate for imitation, the puzzling fact is that monkeys simply do not imitate. Indeed, imitation appears to be a uniquely human ability.
View Article and Find Full Text PDFA sequential regimen of chemotherapy, reduced-intensity conditioning (RIC) for allogeneic stem cell transplantation (SCT), and prophylactic donor lymphocyte transfusion (pDLT) was studied in 103 patients with refractory acute myeloid leukemia (AML). According to published criteria, refractoriness was defined by primary induction failure (PIF; n = 37), early (n = 53), refractory (n = 8), or second (n = 5) relapse. Chemotherapy consisted of fludarabine (4 x 30 mg/m(2)), cytarabine (4 x 2 g/m(2)), and amsacrine (4 x 100 mg/m(2)), followed 4 days later by RIC, comprising 4 Gy total body irradiation (TBI), cyclophosphamide, and antithymocyte globulin.
View Article and Find Full Text PDFBackground: Amyloid light-chain (AL) amyloidosis is a disorder of plasma cells in which depositions of immunoglobulin light-chain fragments cause progressive organ failure and death with a median survival of one year, but autologous stem-cell transplantation can induce high response rates, especially in isolated renal involvement.
Methods: Six patients aged between 43 and 59 years were diagnosed with AL-amyloidosis and had stem cells mobilized with either recombinant human granulocyte colony-stimulating factor (rhG-CSF) alone (n = 2) or cyclophosphamide (2-4 g/m(2)) and rhG-CSF (n = 4). All six patients had kidney involvement and nephrotic syndrome, four had cardiac involvement and two involvement of the vascular, nervous and gastrointestinal systems.
A combination of interpolation methods and local saddle-point search algorithms is probably the most efficient way of finding transition states in chemical reactions. Interpolation methods such as the growing-string method and the nudged-elastic band are able to find an approximation to the minimum-energy pathway and thereby provide a good initial guess for a transition state and imaginary mode connecting both reactant and product states. Since interpolation methods employ usually just a small number of configurations and converge slowly close to the minimum-energy pathway, local methods such as partitioned rational function optimization methods using either exact or approximate Hessians or minimum-mode-following methods such as the dimer or the Lanczos method have to be used to converge to the transition state.
View Article and Find Full Text PDFThe study of explanation, while related to intuitive theories, concepts, and mental models, offers important new perspectives on high-level thought. Explanations sort themselves into several distinct types corresponding to patterns of causation, content domains, and explanatory stances, all of which have cognitive consequences. Although explanations are necessarily incomplete--often dramatically so in laypeople--those gaps are difficult to discern.
View Article and Find Full Text PDFTo build an effective barrier against the penetration of extrinsic agents is one of the skin's main functions. The barrier properties of the stratum corneum and the epidermis have been subject to extensive studies in the past while the role of skin appendages as possible pathways of penetration are only rarely described. In order to study the possible penetration barriers in these complex appendages, a careful investigation of their morphology and ultrastructure has to be done.
View Article and Find Full Text PDFThe influence of flexible walls on the self-diffusion of CH4 in an isolated single walled carbon nanotube, as an example, is studied by molecular dynamics simulations. By simulating the carbon nanotube as a flexible framework we demonstrate that the flexibility has a crucial influence on self-diffusion at low loadings. We show how this influence can be incorporated in a simulation of a rigid nanotube by using a Lowe-Andersen thermostat which works on interface-fluid collisions.
View Article and Find Full Text PDFWe retrospectively analyzed the efficacy of non-invasive ventilation in 35 patients with acute hypoxemic respiratory failure after autologous or allogeneic stem cell transplantation (SCT). Non-invasive ventilation was delivered by a standard face mask or helmet. Decisions to intubate were made according to standard criteria.
View Article and Find Full Text PDFTwo studies explored children's understanding of how the presence of conflicting mental states in a single mind can lead people to act so as to subvert their own desires. Study 1 analyzed explanations by children (4--7 years) and adults of behaviors arising from this sort of 'Ulysses conflict' and compared them with their understanding of conflicting desires in different minds, as well as with changes of mind within an individual across time. The data revealed that only the adults were able to adequately explain the Ulysses conflict.
View Article and Find Full Text PDFThe influence of silicalite-1 pores on the reaction equilibria and the selectivity of the propene metathesis reaction system in the temperature range between 300 and 600 K and the pressure range from 0.5 to 7 bars has been investigated with molecular simulations. The reactive Monte Carlo (RxMC) technique was applied for bulk-phase simulations in the isobaric-isothermal ensemble and for two phase systems in the Gibbs ensemble.
View Article and Find Full Text PDFTwo experiments explored the development of cynicism by examining how children evaluate other people who make claims consistent or inconsistent with their self-interests. In Experiment 1, kindergartners, second graders, and fourth graders heard stories with ambiguous conclusions in which characters made statements that were aligned either with or against self-interest. Older children took into account the self-interests of characters in determining how much to believe them: They discounted statements aligned with self-interest, whereas they accepted statements going against self-interest.
View Article and Find Full Text PDFRecent data suggest that STI571 (Imatinib) induces complete cytogenetic responses in patients with chronic myeloid leukemia (CML) who relapse after allogeneic stem cell transplantation (SCT). However, little is known about molecular responses to STI571 and the duration of leukemia-free survival in these patients. We report on a 43 year old female patient who presented with a relapse from Ph+ CML in December 2000.
View Article and Find Full Text PDFRecent studies have addressed the prevalence and prognostic impact of thrombocytosis in various gynecologic and non-gynecologic malignancies. Thrombocytosis appears to be of prognostic value in certain patients with gynecologic malignancies. In this survey we review the published data and attempt to analyze the prognostic implications of thrombocytosis in patients with gynecologic malignancies.
View Article and Find Full Text PDFIndividuals can infer what others are likely to know by clustering knowledge according to common goals, common topics, or common underlying principles. Although young children are sensitive to underlying principles, that manner of clustering might not prevail when other viable means are presented. Two studies examined how a sample of 256 children at ages 5, 7, 9, and 11 decide how to generalize another person's knowledge when goals, topics, and principles are put in conflict.
View Article and Find Full Text PDFObjectives: Allogeneic transplantation may offer a curative approach to multiple myeloma (MM). We retrospectively analyzed the outcome of patients with multiple myeloma undergoing allogeneic stem cell transplantation in the context of beta(2) microglobulin and chromosome 13q.
Methods: All 13 patients with MM, who were referred to our center for allogeneic stem cell transplantation, were evaluated.
Adults overestimate the detail and depth of their explanatory knowledge, but through providing explanations they recognize their initial illusion of understanding. By contrast, they are much more accurate in making self-assessments for other kinds of knowledge, such as for procedures, narratives, and facts. Two studies examined this illusion of explanatory depth with 48 children each in grades K, 2, and 4, and also explored adults' ratings of the children's explanations.
View Article and Find Full Text PDFUpper and lower gastrointestinal symptoms are major and serious complications after stem cell transplantation. Their main causes are gastrointestinal graft-versus-host disease (GVHD), infections, toxicity, or preexisting gastrointestinal diseases. The clinical presentation of each disease is nonspecific.
View Article and Find Full Text PDFDelayed donor red cell engraftment and prolonged red cell aplasia (PRCA) are well-recognized complications of major ABO-incompatible myeloablative and non-myeloablative hematopoietic stem cell transplantation (HSCT). There is an intense debate about the impact on outcome, severity of hemolysis, association with graft-versus-host disease and survival after blood group-incompatible stem cell transplantation. Therefore, therapeutic strategies should be considered to avoid these possible complications.
View Article and Find Full Text PDFObjectives: To assess efficacy and tolerability of a newly developed helmet for the delivery of non-invasive ventilation in patients with acute respiratory failure.
Patients And Methods: Ten consecutive immunocompromised patients with acute respiratory failure admitted to our intensive care unit were included in the study. The patients were equipped with the helmet and non-invasive ventilation (NIV) was performed.
The rise of appeals to intuitive theories in many areas of cognitive science must cope with a powerful fact. People understand the workings of the world around them in far less detail than they think. This illusion of knowledge depth has been uncovered in a series of recent studies and is caused by several distinctive properties of explanatory understanding not found in other forms of knowledge.
View Article and Find Full Text PDFBackground: ABO mismatch has not been thought to affect the outcome of patients undergoing myeloablative conditioning and allogeneic HPC transplantation. Data on transplant-related complications after ABO-mismatched transplantation after nonmyeloablative conditioning are limited.
Study Design And Methods: Therefore, 40 patients were analyzed after nonmyeloablative conditioning with regard to ABO compatibility.
Background: Nonmyeloablative allogeneic hematopoietic stem-cell transplantation (NST) allows establishment of donor hematopoiesis without eradication of recipient stem cells by chemoradiotherapy. Quantification of donor chimerism may predict graft failure and relapse.
Methods: We quantified donor long-term culture-initiating cells (LTC-IC) in nine patients during the early phase after NST and lineage-specific donor cells of myeloid (CD33+, CD34+, granulocytes) and lymphoid lineage (CD3+, CD4+, CD8+, CD56+) in 38 patients with a median follow-up of 40 weeks after NST.
A single causal agent can often give rise to a cascade of consequences that can be envisioned as a branching pathway in which symptoms are the terminal nodes. In three studies, we investigated whether reasoning about root causes on the basis of such symptoms would conform to a diversity effect analogous to that found in inductive reasoning about properties of hierarchically organized categories. A strong diversity effect was found both for reasoning about medical diseases that drew on existing background knowledge and for reasoning that did not.
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