815 research outputs found
Characteristics of enzymatic induction provoked by chlordane
The effects of various stresses, such as restraint and lowering or raising of environmental temperature, in mice pretreated with chlordane were investigated. (Chlordane is an inhibitor of protein synthesis.) It was found that restraint or exposure to a cold environment for three hours mobilized the chlordane stored in the adipose tissue of mice
Histological study of the sex-change in the skunk clownfish <i>Amphiprion akallopisos</i>
Sex change in the protandrous fish Amphiprion akallopisos Bleeker, 1853 (F.Pomacentridae) has been analysed. Experiments consisted of placing males together after being separated from their mates, and observe changes in gonad histology at different periods, in order to identify signs of the sex change process. The presence of a first invagination on the male gonad wall, and the observation of the first cortical alveoli oocytes as an indication of the beginning of the vitellogenesis process, was the first symptom of the sex change, which has been detected after 18 days in one of the males. Period needed for the sex changing process was size independent. The process by which wall invagination is converted into ovarian lumen in the future mature ovary is also described
Histological study of the sex-change in the skunk clownfish Amphiprion akallopisos
peer reviewedSex change in the protandrous fish Amphiprion akallopisos Bleeker, 1853 (F.Pomacentridae) has been analysed. Experiments consisted of placing males together after being separated from their mates, and observe changes in gonad histology at different periods, in order to identify signs of the sex change process. The presence of a first invagination on the male gonad wall, and the observation of the first cortical alveoli oocytes as an indication of the beginning of the vitellogenesis process, was the first symptom of the sex change, which has been detected after 18 days in one of the males. Period needed for the sex changing process was size independent. The process by which wall invagination is converted into ovarian lumen in the future mature ovary is also described
Women\u27s Leadership Aspirations
Although it is quite easy to identify women leaders, men continue to occupy the vast majority of leadership roles in the world. It has been argued that one of the reasons for this differential is women\u27s aspirations for leadership are less than men\u27s. Women\u27s leadership aspirations are defined in this chapter as girls\u27 and women\u27s longing for and intentional seeking after a future that catalyze their visions, goals, or calling for themselves into reality, whether or not they use the term leadership to describe their aspirations
Development of the Fetal Vermis: New Biometry Reference Data and Comparison of 3 Diagnostic Modalities-3D Ultrasound, 2D Ultrasound, and MR Imaging
Normal biometry of the fetal posterior fossa rules out most major anomalies of the cerebellum and vermis. Our aim was to provide new reference data of the fetal vermis in 4 biometric parameters by using 3 imaging modalities, 2D ultrasound, 3D ultrasound, and MR imaging, and to assess the relation among these modalities. A retrospective study was conducted between June 2011 and June 2013. Three different imaging modalities were used to measure vermis biometry: 2D ultrasound, 3D ultrasound, and MR imaging. The vermian parameters evaluated were the maximum superoinferior diameter, maximum anteroposterior diameter, the perimeter, and the surface area. Statistical analysis was performed to calculate centiles for gestational age and to assess the agreement among the 3 imaging modalities. The number of fetuses in the study group was 193, 172, and 151 for 2D ultrasound, 3D ultrasound, and MR imaging, respectively. The mean and median gestational ages were 29.1 weeks, 29.5 weeks (range, 21-35 weeks); 28.2 weeks, 29.05 weeks (range, 21-35 weeks); and 32.1 weeks, 32.6 weeks (range, 27-35 weeks) for 2D ultrasound, 3D ultrasound, and MR imaging, respectively. In all 3 modalities, the biometric measurements of the vermis have shown a linear growth with gestational age. For all 4 biometric parameters, the lowest results were those measured by MR imaging, while the highest results were measured by 3D ultrasound. The inter- and intraobserver agreement was excellent for all measures and all imaging modalities. Limits of agreement were considered acceptable for clinical purposes for all parameters, with excellent or substantial agreement defined by the intraclass correlation coefficient. Imaging technique-specific reference data should be used for the assessment of the fetal vermis in pregnanc
Learning from our Multi-Stage Collaborative Autoethnography
This article is a reflection on eight, then seven, now five women’s collaborative efforts to explore the development of our own leader identities. While each of us conducts research on women and leadership, we are a diverse group of women: we were born in three different countries (United States, Paraguay, and New Zealand) and currently live in three different countries (United States, Canada, and New Zealand). We are of diverse races, sexual orientations, and generations; we have leadership experiences in a variety of disciplines and industries; and we vary in the priority we place on this study. In this paper, we review our experiences conducting research during the first three plus years of our collaborative autoethnographic study and share what we learned from those experiences. We address previously published considerations for developing collaborative autoethnographies including: the number of participants involved; the extent of involvement of the participants and the level of collaboration during the study; the collaborative approaches used in the study; and the approaches to writing. We add a reflection on our leadership practices throughout the study and on the confidentiality challenges that emerged. We also discuss how our division of the study into multiple life stages and multiple projects within the life stages has influenced our experiences and how the challenges resulting from the long duration of our study have influenced our productivity and are expected to influence our future plans. Our lessons learned should prove useful as other autoethnographic research groups begin their own research processes
The Sunyaev-Zeldovich effect in superclusters of galaxies using gasdynamical simulations: the case of Corona Borealis
[Abridged] We study the thermal and kinetic Sunyaev-Zel'dovich (SZ) effect
associated with superclusters of galaxies using the MareNostrum Universe SPH
simulation. We consider superclusters similar to the Corona Borealis
Supercluster (CrB-SC). This paper is motivated by the detection at 33GHz of a
strong temperature decrement in the CMB towards the core of this supercluster.
Multifrequency observations with VSA and MITO suggest the existence of a
thermal SZ effect component in the spectrum of this cold spot, which would
account for roughly 25% of the total observed decrement. We identify nine
regions containing superclusters similar to CrB-SC, obtain the associated SZ
maps and calculate the probability of finding such SZ signals arising from hot
gas within the supercluster. Our results show that WHIM produces a thermal SZ
effect much smaller than the observed value. Neither can summing the
contribution of small clusters and galaxy groups in the region explain the
amplitude of the SZ signal. When we take into account the actual posterior
distribution from the observations, the probability that WHIM can cause a
thermal SZ signal like the one observed is <1%, rising up to a 3.2% when the
contribution of small clusters and galaxy groups is included. If the
simulations provide a suitable description of the gas physics, then we conclude
that the thermal SZ component of the CrB spot most probably arises from an
unknown galaxy cluster along the line of sight. The simulations also show that
the kinetic SZ signal associated with the supercluster cannot provide an
explanation for the remaining 75% of the observed cold spot in CrB.Comment: Accepted for publication in MNRAS. 14 pages, 9 figure
Petrophysics of Chicxulub Impact Crater's Peak Ring
A new set of physical property measurements was undertaken on 29 peak-ring samples from the IODP-ICDP Expedition 364. Among the studied lithologies, the dominant one recovered in the peak ring consists of shocked granitoid rocks (19 samples). Porosity measurements with two independent methods (triple weight and C-14-PMMA porosity mapping) concur and bring new observations on the intensity and distribution of fracturing and porosity in these shocked target rocks. Characterization of the porous network is taken a step further with two other independent methods (electrical and permeability measurements). Electrical properties such as the cementation exponent (1.59 m < 1.87) and the formation factor (21 F < 103) do not compare with other granites from the published literature; they point at a type of porosity closer to clastic sedimentary rocks than to crystalline rocks. Permeabilities of the granitoid rocks range from 0.1 to 7.1 mD under an effective pressure of similar to 10 MPa. Unlike other fresh to deformed and altered granitoid rocks from the literature compared in this study, this permeability appears to be relatively insensitive to increasing stress (up to similar to 40 MPa), with implications for the nature of the porous network, again, behaving more like cemented clastic rocks than fractured crystalline rocks. Other analyzed lithologies include suevite and impact melt rocks. Relatively low permeability (10(-3) mD) measured in melt-rich facies suggest that, at the matrix scale, these lithologies cutting through more permeable peak-ring granitoid rocks may have been a barrier to fluid flow, with implications for hydrothermal systems.Peer reviewe
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