Using a non-invasive MRI technique for measuring the refractive index distribution through the crystalline lens, refractive index maps were obtained through 20 intact isolated human lenses (7-82years). Focal length measurements, obtained by simulated light ray propagation through each index map were found to be in agreement with direct measurements performed on a scanning laser apparatus. With ...

The localization of genes within the nuclear space is of paramount importance for proper genome functions. However, very little is known on the cis-acting elements determining subnuclear positioning of chromosome segments. We show here that the D4Z4 human subtelomeric repeat localizes a telomere at the nuclear periphery. This perinuclear activity lies within an 80 bp sequence included within a ...

Wind affects adversely the cooling tower thermal performance. A field investigation was carried out to study the thermal performance of Heller cooling towers under wind conditions, involving measurement of wind velocity and its direction around the cooling tower, and obtaining water flow rates and temperatures at the cooling tower inlet and outlet. Results show that air suction at the tower top...

Processes of social opinion formation might be dominated by a set of highly influential agents acting as ‘opinion leaders’. Here we explore whether such a perspective could shed light on the dynamics of a well known economic sentiment index. To this end, we hypothesize that the respondents of the survey under investigation form a core-periphery network, and we identify those agents that define ...

•A histologically low-grade cervical clear cell lesion was observed.•Proliferating cells were seen only at the periphery of this lesion.•Due to its low proliferation index, this may represent a precursor of clear cell carcinoma.•Further definition of such lesions may allow for more minimal management.

Intermediate-scale (or “meso-scale”) structures in networks have received considerable attention, as the algorithmic detection of such structures makes it possible to discover network features that are not apparent either at the local scale of nodes and edges or at the global scale of summary statistics. Numerous types of meso-scale structures can occur in networks, but investigations of such f...

Most studies concerned with empirical social networks are conducted on the level of individuals. The interaction of scientists is an especially popular research area, with the growing importance of international collaboration as a common sense result. To analyze patterns of cooperation across nations, this paper investigates the structure and evolution of cross-country co-authorships for the fi...