Differential expression of fibulin family proteins in the para-cervical weak zone and other areas of human fetal membranes.

OBJECTIVE: Human fetal membranes (FM) at term have been shown to contain a weak zone in the region overlying the cervix which exhibits characteristics of increased collagen remodeling and apoptosis. It has been hypothesized that the FM rupture initiation site is within this weak zone. Although the FM weak zone has been partially characterized, it is unclear what structural differences in the extracellular matrix result in its decreased rupture strength. A screen for differentially expressed proteins in the amnion of the weak zone versus other FM areas demonstrated that fibulin 1 was decreased. We investigated potential regional differences in all fibulin protein family members. METHODS: FM fibulins were localized by immunohistochemistry. Detected fibulins were screened by Western blot for differences in abundance in the amnion of the weak zone versus non-weak zone FM regions. Amnion epithelial and mesenchymal cells were also screened for fibulin production. RESULTS: Fibulins 1 and 5 were detected in the cytoplasm of and in a pericellular pattern surrounding all FM cells, and in a dense extracellular pattern in the amniotic compact zone. Fibulin 3 was detected within the cytoplasm of amnion epithelial and chorion trophoblast cells. Fibulins 2 and 4 were not detected. Fibulins 1, 3 and 5 demonstrated decreased abundance of 33%, 63% and 58% (all P<0.01) in amnion of the weak zone relative to other FM regions. Amnion cells produced all three detected fibulins. Furthermore, TNF inhibited amnion cell fibulin production in a dose dependent manner. CONCLUSION: Fibulins 1, 3 and 5 were localized coincident with major microfibrillar networks in amnion. Each showed decreased abundance in the amnion component of the FM weak zone. Amnion epithelial and mesenchymal cells produced all three fibulins and their abundance was inhibited by TNF. We speculate that the amnion microfibrillar layer undergoes significant remodeling with the development of the FM weak zone.

Human engineering and habitability: the critical challenges for the International Space Station.

As the duration of spaceflight increases, the impact of habitability on mission success becomes significant. Habitability is based on the qualities and capabilities of an environment that enable people to work and live. Poor habitability can impact productivity, safety, well-being, and performance. The International Space Station (ISS) Operational Habitability Project has been established to address the increased role of habitability for ISS. The primary objective of the project is to establish a pool of data from which opinions and decisions for judging and improving habitability on ISS will be generated. The main activities of the project are to: 1) collect and interpret data related to habitability on ISS; 2) identify Operational Habitability Lessons Learned; and 3) provide data summaries, judgments, and recommendations for the improvement of habitability. As an example, the ISS Operational Habitability Project has provided significant inputs to a current ISS issue regarding stowage. In this situation, a lack of prioritization on habitability resulted in a less than ideal situation. Operational Habitability data from previous missions was identified and summarized to provide inputs to assist in working the issues toward a resolution that supports habitability on ISS.

Summary of current issues regarding space flight habitability.

One of the implicit, yet often under-emphasized qualities of human tended spaceflight is the habitability of the spacecraft and mission. This document summarizes some of the points that characterize the current status of this topic. In addition, the summary concludes with goals for future development for this issue.

Judgments of relative time-to-contact of more than two approaching objects: toward a method.

Observers reported which of as many as eight computer-generated approaching objects would "hit" them first. Accuracy was above chance probability except when two-object displays contained pictorial relative size information that contradicted relative time-to-contact (TTC) information. Mean d' and response time was greater, but mean efficiency (Barlow, 1978) was smaller with eight objects than with two. Performance was less effective when global expansion contradicted TTC information than when local expansion contradicted TTC. Results suggest that observers can judge relative TTC with as many as eight objects when certain sources of information are consistent with TTC and that observers rely on information other than, or in conjunction with, optical TTC. Also, the sources of visual information that affect performance may vary with set size, and identification (but not detection) judgments may be constrained by limited-capacity processing.