The nucleus acts as a ruler tailoring cell responses to spatial constraints.

The microscopic environment inside a metazoan organism is highly crowded. Whether individual cells can tailor their behavior to the limited space remains unclear. In this study, we found that cells measure the degree of spatial confinement by using their largest and stiffest organelle, the nucleus. Cell confinement below a resting nucleus size deforms the nucleus, which expands and stretches its envelope. This activates signaling to the actomyosin cortex via nuclear envelope stretch-sensitive proteins, up-regulating cell contractility. We established that the tailored contractile response constitutes a nuclear ruler-based signaling pathway involved in migratory cell behaviors. Cells rely on the nuclear ruler to modulate the motive force that enables their passage through restrictive pores in complex three-dimensional environments, a process relevant to cancer cell invasion, immune responses, and embryonic development.

Rafting behaviour of seabirds as a proxy to describe surface ocean currents in the Balearic Sea.

Spatio-temporal variability of surface geostrophic mesoscale currents in the Balearic Sea (western Mediterranean) is characterized from satellite altimetry in combination with in-situ velocity measurements collected, among others, by drifting buoys, gliders and high-frequency radar. Here, we explore the use of tracking data from living organisms in the Balearic Sea as an alternative way to acquire in-situ velocity measurements. Specifically, we use GPS-tracks of resting Scopoli's shearwaters Calonectris diomedea, that act as passive drifters, and compare them with satellite-derived velocity patterns. Results suggest that animal-borne GPS data can be used to identify rafting behaviour outside of the breeding colonies and, furthermore, as a proxy to describe local sea surface currents. Four rafting patterns were identified according to the prevailing driving forces responsible for the observed trajectories. We find that 76% of the bird trajectories are associated with the combined effects of slippage and Ekman drift and/or surface drag; 59% are directly driven by the sea surface currents. Shearwaters are therefore likely to be passively transported by these driving forces while resting. The tracks are generally consistent with the mesoscale features observed in satellite data and identified with eddy-tracking software.

Compensation by the CIEMAT/NIST-method of long-term effects in LSC measurements of beta emitters.

A systematic evaluation of activity concentrations of 3H, 63Ni and 14C by using the CIEMAT/NIST method has been carried out over time intervals of 4, 2.4 and 2.3 years, respectively. It proves that the CIEMAT/NIST method can compensate, with no need for additional checking sources or procedures, for count losses and quench parameter reduction in long-term measurements with LSC spectrometers and allows one to obtain very accurate activity concentration values by using a quench curve close to the nuclide measurements. If this requirement of the method is not fulfilled, significant discrepancies, up to 5.6% for 3H, 1.5% for 63Ni and 0.35% for 14C, can be obtained in only 1-year time difference.

A method for the comparison of performance of gamma-ray spectrometry calibration cocktails.

In order to make quantitative assessments about the usefulness of different gamma-ray emitting radionuclide cocktails to carry out efficiency calibrations of gamma-ray spectrometers, a method has been developed that allows the comparison of their different performances and to optimize the choice of gamma energy lines for the radionuclides within a specific cocktail. The method has been applied to compare different cocktail configurations obtained from measurements made in the laboratory with monoenergetic radionuclides, and their relative performances are presented and discussed.

Standardization of 32P/33P and 204Tl by liquid scintillation counting.

Two solutions, one of 32P with a significant contribution of 33P, and another one of 204Tl were standardized by liquid scintillation counting in the frame of two intercomparison exercises organized by the BIPM in 2002. For the 32P solution, the counting efficiencies for 32P and 33P were obtained by the CIEMAT/NIST method. The individual contributions of 32P and 33P were determined by fitting a set of measurements to a function of the half-lives and counting efficiencies of both component nuclides. 204Tl was also standardized by the CIEMAT/NIST method using two counters, three scintillators, HiSafe 3, Insta-Gel Plus and Ultima-Gold, and two different kinds of samples. A total of 480 samples were measured over 45 days with results in full agreement within the uncertainties considered. The efficiency values are also compared to those used in the previous 204Tl intercomparison (1997).

Vibrio navarrensis sp. nov., a species from sewage.

A group of 11 strains, mostly isolated from sewage water in the Province of Navarra, Spain, were found to constitute a DNA relatedness group which is 2 to 39% related to 23 species of the genus Vibrio and 2 to 3% related to two Aeromonas species. Phenotypically, these strains have all of the properties that define the genus Vibrio. However, they differ from the previously described species by three or more properties. The strains are negative for arginine, ornithine, and lysine decarboxylase activities and the Voges-Proskauer test and are unable to utilize putrescine, gluconate, glucuronate, and histidine. They utilize and produce acid from sucrose and grow at 40 degrees C. All strains grow in the presence of 0.5% (wt/vol) NaCl, and seven strains grow weakly in peptone water lacking NaCl. The group of strains which we studied can also be differentiated from other Vibrio species by fatty acid content. The G+C ratio of the DNA is 45 to 47 mol%. The name Vibrio navarrensis sp. nov. is proposed for these strains; strain 1397-6 (= CIP 103381) is the type strain.