Tufts University

About: Tufts University is a education organization based out in Medford, Massachusetts, United States. It is known for research contribution in the topics: Population & Medicine. The organization has 32800 authors who have published 66881 publications receiving 3451152 citations. The organization is also known as: Tufts College & Universitatis Tuftensis.

Environmental causes of cancer: endocrine disruptors as carcinogens

Abstract: Environmental endocrine disrupting chemicals (EDCs), including pesticides and industrial chemicals, have been and are released into the environment producing deleterious effects on wildlife and humans. The effects observed in animal models after exposure during organogenesis correlate positively with an increased incidence of malformations of the male genital tract and of neoplasms and with the decreased sperm quality observed in European and US populations. Exposure to EDCs generates additional effects, such as alterations in male and female reproduction and changes in neuroendocrinology, behavior, metabolism and obesity, prostate cancer and thyroid and cardiovascular endocrinology. This Review highlights the carcinogenic properties of EDCs, with a special focus on bisphenol A. However, humans and wildlife are exposed to a mixture of EDCs that act contextually. To explain this mindboggling complexity will require the design of novel experimental approaches that integrate the effects of different doses of structurally different chemicals that act at different ages on different target tissues. The key to this complex problem lies in the adoption of mathematical modeling and computer simulations afforded by system biology approaches. Regardless, the data already amassed highlight the need for a public policy to reduce exposure to EDCs.

Influenza seasonality: underlying causes and modeling theories.

Abstract: Influenza (or “flu”) leads to the hospitalization of more than 200,000 people yearly and results in 36,000 deaths from flu or flu-related complications in the United States ([15][1]), striking both the elderly and infant populations particularly hard ([24][2]). Two members of the

The Development of Close Relationships in Japan and the United States: Paths of Symbiotic Harmony and Generative Tension

Abstract: Findings from research on parent-child and adult mate relationships suggest that there are different paths of development in Japan and the United States. In Japan, the path is one of symbiotic harmony, as seen in the emphasis on union in infancy, others' expectations in childhood, the stability of relationships with parents and peers in adolescence, and assurance about the mate relationship in adulthood. In the United States, the path is one of generative tension, as seen in the tug between separation and reunion in infancy, the emphasis on personal preferences in childhood, the transfer of closeness from parents to peers in adolescence, and the emphasis on trust-a faith and hope in new relationships-in adulthood. The notion that there are different paths of development challenges Western investigators' presumption that certain processes-separation-individuation, use of the relational partner as a secure base for exploration, and conflict between partners-are central in all relationships. The notion of different paths also challenges the assumption of many cross-cultural investigators that relationships in the United States are less valued or weaker than those in Japan; this article highlights cultural differences in the meaning and dynamics, as opposed to the importance and strength, of relationships. The model suggests a need to investigate the processes underlying, and the adaptive consequences of, these two alternative paths.

Haploid Genetic Screens in Human Cells Identify Host Factors Used by Pathogens

Abstract: Loss-of-function genetic screens in model organisms have elucidated numerous biological processes, but the diploid genome of mammalian cells has precluded large-scale gene disruption. We used insertional mutagenesis to develop a screening method to generate null alleles in a human cell line haploid for all chromosomes except chromosome 8. Using this approach, we identified host factors essential for infection with influenza and genes encoding important elements of the biosynthetic pathway of diphthamide, which are required for the cytotoxic effects of diphtheria toxin and exotoxin A. We also identified genes needed for the action of cytolethal distending toxin, including a cell-surface protein that interacts with the toxin. This approach has both conceptual and practical parallels with genetic approaches in haploid yeast.

Synchronization in networks of excitatory and inhibitory Neurons with sparse, random connectivity

Abstract: In model networks of E-cells and I-cells (excitatory and inhibitory neurons, respectively), synchronous rhythmic spiking often comes about from the interplay between the two cell groups: the E-cells synchronize the I-cells and vice versa. Under ideal conditions--homogeneity in relevant network parameters and all-to-all connectivity, for instance--this mechanism can yield perfect synchronization. We find that approximate, imperfect synchronization is possible even with very sparse, random connectivity. The crucial quantity is the expected number of inputs per cell. As long as it is large enough (more precisely, as long as the variance of the total number of synaptic inputs per cell is small enough), tight synchronization is possible. The desynchronizing effect of random connectivity can be reduced by strengthening the E → I synapses. More surprising, it cannot be reduced by strengthening the I → E synapses. However, the decay time constant of inhibition plays an important role. Faster decay yields tighter synchrony. In particular, in models in which the inhibitory synapses are assumed to be instantaneous, the effects of sparse, random connectivity cannot be seen.