Host-Pathogen Interaction and Human Disease: Part 2: Helicobacter pylori and Gastric Cancer (48:57)

submitted by: video_collector
Helicobacter pylori lives in the human stomach. It causes gastritis, ulcer disease and even gastric cancer. Some H. pylori can inject a protein, CagA, into gastric epithelial cells. CagA interacts with the tight junctions that bind cells together and with signaling molecules affecting motility and proliferation. CagA is associated with ulcer disease and cancer but we don't understand how it works to favor malignancy. Not long ago in history most humans carried H. pylori ; the incidence of...

Cell Organization & Cell Motility: Part 3: Principles of Cellular Organization: The Universal Cytoskeleton (29:17)

submitted by: scivee-team
In the third part, I discuss how the complex shapes of cells are created by the cytoskeleton, and I compare and contrast prokaryotes (which have actin-, tubulin-, and intermediate filament -like proteins) and eukaryotes in this regard. In particular, I speculate that cytoskeletal dynamics were necessary to evolve simple bacterial shapes and cell division, but that additional layers of complexity (namely regulated nucleation and molecular motors) allowed eukaryotes to evolve more complex...

Cell Organization & Cell Motility: Part 2: Force Generation by Actin Assembly: Theories and Experiments (46:16)

submitted by: scivee-team

The second part is devoted to understanding how the polymerization of actin can produce, which is a current area of research in our laboratory. Here, I cover theories for how polymerization might be used to produce forces, and our efforts to test these models using optical traps, atomic force microscopes, and nanofabricated devices.

Dynamic Mechanism Design

submitted by: dougramsey
I will consider the design of efficient and profit-maximizing Bayesian incentive-compatible mechanisms for general dynamic environments with private information. In the environment, agents observe a sequence of private signals over a number of periods. In each period, the agents report their private signals and choose public (contractible) and private actions based on the reports. The probability distribution over future signals may depend on both past signals and past decisions. The general...

Wellness and Diseases: Implications of Important Microbiota

submitted by: dougramsey
The microbiota in personalized preventative medicine: how do we get from here to there and what role does metagenomics play? Synopsis—In this session we will (i) identify major questions and hurdles we face in under standing the integration between the human microbiota and human biology (in health and disease) and (ii) determine how these major questions may be addressed and what tools/technologies are required to overcome cur rent obstacles. We will attempt to identify immediate and...

Polyketide Biosynthesis: The Erythromycin Example - Part 1: Overview of Polyketides and Polyketide Biosynthesis (34:10)

submitted by: video_collector

In the first part, an overview of polyketides and polyketide biosynthesis is presented. A rationale for investigating polyketide biosynthesis is also presented.

For further informaton see: http://www.ascb.org/ibioseminars/Khosla/Khosla1.cfm

The Dynamic Bacterial Cell: Part 1: Dynamics of Bacterial Chromosome Organization, Segregation, and Cytokinesis (34:32)

submitted by: video_collector
Most bacterial cells have their genes arranged in a single circle of DNA. The circle of DNA plus some attached proteins is referred to as the bacterial chromosome. Up until quite recently, it was thought that the chromosome in the tiny bacteria cell resembled a tangled ball of yarn. It is now known that multiple factors cooperate to condense DNA into a highly dynamic assembly of supercoiled loops. Although there is variability in the lower levels of chromosome structure, the global...

Host-Pathogen Interaction and Human Disease: Part 1: What is a Pathogen? Trying to Understand Human Biology by the Study of Pathogenic Bacteria (37:48)

submitted by: video_collector
Ninety percent of the cells humans carry are microbes. Only a few of the bacteria we encounter are pathogenic and can cause disease. Pathogens possess the inherent ability to cross anatomic barriers or breach other host defenses that limit the microbes that make up our normal flora. A significant part of human evolution has gone into developing ways to thwart microbial intrusion. In turn, microbes have come up with clever ways to avoid and circumvent host defenses but human — microbe...