Distribution of α7 Nicotinic Acetylcholine Receptor Subunit mRNA in the Developing Mouse.

Homomeric α7 nicotinic acetylcholine receptors (nAChRs) are abundantly expressed in the central and peripheral nervous system (CNS and PNS, respectively), and spinal cord. In addition, expression and functional responses have been reported in non-neuronal tissue. In the nervous system, α7 nAChR subunit expression appears early during embryonic development and is often transiently upregulated, but little is known about their prenatal expression outside of the nervous system. For understanding potential short-term and long-term effects of gestational nicotine exposure, it is important to know the temporal and spatial expression of α7 nAChRs throughout the body. To that end, we studied the expression of α7 nAChR subunit mRNA using highly sensitive isotopic in situ hybridization in embryonic and neonatal whole-body mouse sections starting at gestational day 13. The results revealed expression of α7 mRNA as early as embryonic day 13 in the PNS, including dorsal root ganglia, parasympathetic and sympathetic ganglia, with the strongest expression in the superior cervical ganglion, and low to moderate levels were detected in brain and spinal cord, respectively, which rapidly increased in intensity with embryonic age. In addition, robust α7 mRNA expression was detected in the adrenal medulla, and low to moderate expression in selected peripheral tissues during embryonic development, potentially related to cells derived from the neural crest. Little or no mRNA expression was detected in thymus or spleen, sites of immune cell maturation. The results suggest that prenatal nicotine exposure could potentially affect the nervous system with limited effects in non-neural tissues

Factors Influencing Career Choice for Women in Science, Mathematics, and Technology: The Importance of a Transforming Experience

Organizations in the business sector, as well as government and academia, continue to demand intelligent professionals trained in science, mathematics, and technology. This paper explores factors that may influence women's initial choices to pursue careers in these fields. In addition to the many well-established factors that guide an individual's career choice, we propose that women who choose careers in science and technology have a subset of common early experiences that encourage them to pursue a career path still regarded as contrary to traditional gender roles for women. For many women, this common background is a transforming experience that supports their career choice in science, mathematics, and technology. This transforming experience is composed of personal contact with a role model and often an intimate involvement with the process that serves as an invitation into the world of scientific inquiry. The researchers outline a model for women's career selection in these nontraditional fields, and our results suggest some recommendations for increasing the numbers of women in these careers

Trajectory attractors for the Sun-Liu model for nematic liquid crystals in 3D

In this paper we prove the existence of a trajectory attractor (in the sense of V.V. Chepyzhov and M.I. Vishik) for a nonlinear PDE system coming from a 3D liquid crystal model accounting for stretching effects. The system couples a nonlinear evolution equation for the director d (introduced in order to describe the preferred orientation of the molecules) with an incompressible Navier-Stokes equation for the evolution of the velocity field u. The technique is based on the introduction of a suitable trajectory space and of a metric accounting for the double-well type nonlinearity contained in the director equation. Finally, a dissipative estimate is obtained by using a proper integrated energy inequality. Both the cases of (homogeneous) Neumann and (non-homogeneous) Dirichlet boundary conditions for d are considered.Comment: 32 page

A Technique to Measure Strain Distributions in Single Wood Pulp Fibers

Environmental scanning electron microscopy (ESEM) and digital image correlation (DIC) were used to measure microstrain distributions on the surface of wood pulp fibers. A loading stage incorporating a fiber gripping system was designed and built by the authors. Fitted to the tensile substage of an ESEM or a Polymer Laboratories MINIMAT tester, it provided a reliable fiber straining mechanism. Black spruce latewood fibers (Picea mariana (Mill) B.S.P.) of a near-zero microfibril angle displayed a characteristically linear load elongation form. ESEM was able to provide real-time, high magnification images of straining fibers, crack growth, and complex single fiber failure mechanisms. Digital images of single fibers were also captured and used for subsequent DIC-based strain analysis. Surface displacement and strain maps revealed nonuniform strain distributions in seemingly defect-free fiber regions. Applied tensile displacements resulted in a strain band phenomenon. Peak strain (concentration) values within the bands ranged from 0.9% to 8.8%. It is hypothesized that this common pattern is due to a combination of factors including the action of microcompressive defects and straining of amorphous cell-wall polymeric components. Strain concentrations also corresponded well to locations of obvious strain risers such as visible cell-wall defects. Results suggest that the ESEM-based DIC system is a useful and accurate method to assess and, for the first time, measure fiber micro-mechanical properties

Using the Internet as a Pleasure Travel Planning Tool: An Examination of the Sociodemographic and Behavioral Characteristics among Internet Users and Nonusers

A critical prerequisite for the formulation of effective travel marketing strategies in the next decade must include an understanding of the influence exerted through the Internet. The increasing presence of the Internet as an instrument for advertising travel destinations and travel-related services highlights its importance as a factor in travelers’ decision-making processes. This exploratory investigation examined travelers who requested on-line information about a potential vacation destination using the Internet. Results of this investigation suggest that Internet “users, when compared with “nonusers,” are more educated, have higher household incomes, use commercial lodging accommodations while traveling, tend to travel by air, and spend more money on travel-related expenses on a per diem basis. Implications for target marketing strategies designed for travel destination areas, services, and facilities are discussed

Predicting a Behavioral Profile for Pleasure Travelers on the Basis of Internet Use Segmentation

In an attempt to create a behavioral profile of pleasure travelers segmented based on Internet use, 5,319 pleasure travelers were interviewed. Initially, the respondents were classified as an Internet user or Internet nonuser based on whether or not they would use the Internet to seek travel related information. Using discriminant analysis, chi square, and analysis of variance statistical techniques, a profile of demographic and behavioral characteristics was created. The results of this study suggest that people who use the Internet to search for travel-related information are likely to be people who are (a) college-educated owners of computers, (b) less than 45 years of age, (c) stay more often in commercial lodging establishments, and (d) spend more money each day while traveling. Implications for marketing managers and future research are discussed

Muon-Spin Rotation Measurements of an Unusual Vortex-Glass Phase in the Layered Superconductor Bi2.15Sr1.85CaCu2O8+δ

Muon-spin rotation measurements, performed on the mixed state of the classic anisotropic superconductor Bi2.15Sr1.85CaCu2O8+δ, obtain quantities directly related to two- and three-body correlations of vortices in space. A novel phase diagram emerges from such local probe measurements of the bulk, revealing an unusual glassy state at intermediate fields which appears to freeze continuously from the equilibrium vortex liquid but differs both from the lattice and the conventional high-field vortex glass state in its structure.Publisher PDFPeer reviewe

Sociology and Social Work: Science and Art

Excerpt from the full-text article: We live in an age of specialization and usually find it beneficial, perhaps even essential. However, we have been aware since Marx\u27s time at least that the division of labor has its cost. And though we may be a long way from the unconpartmentalized utopia where an individual might do four different kinds of work in a single day, we cannot afford to let the assumptions which underlie the separation of important jobs and functions go without periodic reexamination. The separation of the work of the sociologist (or, indeed, any social scientist) and the social worker is one area where reconsideration is overdue. In examining the taken-for-granted bases of this division of labor, we may find they obscure more than they clarify

The Civic Functionality of Campaigns: Voter Competence, Mobilization, and Salience

Leading to an election, television screens are consumed by the faces of candidates; radio shows are teeming with voices of campaign professionals; analysts and voters are being endlessly presented with new information, policy standpoints, and poll numbers. In this busy day and age it can be difficult, inconvenient, and time consuming for voters to seek out political knowledge for themselves. Campaigns can be seemingly interminable and it is far easier for a voter to take their information from these ongoing campaigns than to pursue the information from various sources on their own. Campaigns supply voters with data, analyses, and platforms that can aid them in mobilizing and casting an informed vote. Our question is do campaigns really matter and do they actually affect the amount of knowledge that a voter. We also look to see if campaigns encourage voter mobilization through various forms of media like social media and news or if they have no effect on voter turnout at the polls