In the Service of Citizenship: A Study of Student Involvement in Community Service

I learn more through my volunteer work than I ever do in any of my classes at school. Talking to people from diverse backgrounds provides so much insight that people just can\u27t imagine. I study all these different theories in political science and sociology, but until you get a chance to see how the social world influences people\u27s everyday lives, it just doesn\u27t have that much meaning. I have been involved in volunteer work ever since I was in high school, and I\u27ll probably continue to do stuff like Habitat [for Humanity] until I\u27m old and gray. I get a lot out of working to serve others, and it\u27s a good feeling to know that I have helped someone even if it\u27s in some small way. It helps me to cherish people more and understand what life is all about

The Dynamic Tensions of Service Learning in Higher Education: A Philosophical Perspective

Senior faculty in a peace and justice program at a small liberal arts college reject the efforts of a student affairs professional to help the faculty connect their teaching to practice through service activities in the local community. One faculty member openly wonders how out-of-class activities such as community service have anything to do with interdisciplinary theories of social justice. A director of an office of community service is upset because the provost has decided to develop a Center for Community Service Learning. The director sees this as an attempt to usurp the good work of student affairs and feels that attempts to engage faculty will be difficult, if not futile. A department chair in an American Thought and Language program at a large research university asks an associate professor being considered for promotion to full professor to explain in writing to the promotion and tenure committee the relevance of his research on service learning. Both the chair and the committee are apprehensive about service learning as a legitimate area of scholarly inquiry. And finally, a local social service agency in a university town has had its till of student volunteers after repeatedly receiving complaints from clients about patronizing attitudes expressed by the students

Hybrid Vector and Method Resulting in Protein Overproduction by Eukaryotic Cells

A hybrid vector carrying a first and second DNA segments operationally linked thereto, the first DNA segment encoding a protein capable of cross-linking to the cap structure of mRNA and mediating ribosome-binding, and the second DNA segment encoding a polypeptide or protein, the vector being capable of replication, transcription and translation to express the factor and the polypeptide or protein upon transformation of a eukaryotic host, and the polypeptide or protein being expressed at a level higher than the level of expression thereof in the absence of the first DNA segment. A eukaryotic host is transformed with this hybrid vector. Also disclosed is a method of increasing the synthesis of a polypeptide or protein in a eukaryotic host cell

A Physical Model of Lyman Alpha Emitters

We present a simple physical model for populating dark matter halos with Lyman Alpha Emiiters(LAEs) and predict the physical properties of LAEs at z~3-7. The central tenet of this model is that the Ly-alpha luminosity is proportional to the star formation rate (SFR) which is directly related to the halo mass accretion rate. The only free parameter in our model is then the star-formation efficiency (SFE). An efficiency of 2.5% provides the best-fit to the Ly-alpha luminosity function (LF) at redshift z=3.1, and we use this SFE to construct Ly-alpha LFs at other redshifts. Our model reproduce the Ly-alpha LFs, stellar ages, SFR ~1-10; Msun/yr, stellar masses ~ 10^7-10^8 Msun and the clustering properties of LAEs at z~3-7. We find the spatial correlation lengths ro ~ 3-6 Mpc/h, in agreement with the observations. Finally, we estimate the field-to-field variation ~ 30% for current volume and flux limited surveys, again consistent with observations. Our results suggest that the star formation, and hence Ly-alpha emission in LAEs is powered by the accretion of new material, and that the physical properties of LAEs do not evolve significantly over a wide range of redshifts. Relating the accreted mass, rather than the total mass of halos, to the Ly-alpha luminosity of LAEs naturally gives rise to the duty cycle of LAEs.Comment: Published in Ap

Growth and predation activity at deep-sea hydrothermal vents along the Galápagos Rift

Growth rates of unclassified mussels collected from hydrothermal vents on the Pacific Ocean (2500 m) are among the highest recorded for deep-sea species. Mature mussels have mean growth rates of about 1 cm yr-1 which are comparable to growth rates of shallow water mussels...

Metallicities of Emission-Line Galaxies from HST ACS PEARS and HST WFC3 ERS Grism Spectroscopy at 0.6 < z < 2.4

Galaxies selected on the basis of their emission line strength show low metallicities, regardless of their redshifts. We conclude this from a sample of faint galaxies at redshifts between 0.6 < z < 2.4, selected by their prominent emission lines in low-resolution grism spectra in the optical with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST) and in the near-infrared using Wide-Field Camera 3 (WFC3). Using a sample of 11 emission line galaxies (ELGs) at 0.6 < z < 2.4 with luminosities of -22 < M_B < -19, which have [OII], H\beta, and [OIII] line flux measurements from the combination of two grism spectral surveys, we use the R23 method to derive the gas-phase oxygen abundances: 7.5 < 12+log(O/H) < 8.5. The galaxy stellar masses are derived using Bayesian based Markov Chain Monte Carlo (\piMC^2) fitting of their Spectral Energy Distribution (SED), and span the mass range 8.1 < log(M_*/M_\sun) < 10.1. These galaxies show a mass-metallicity (M-L) and Luminosity-Metallicity (L-Z) relation, which is offset by --0.6 dex in metallicity at given absolute magnitude and stellar mass relative to the local SDSS galaxies, as well as continuum selected DEEP2 samples at similar redshifts. The emission-line selected galaxies most resemble the local "green peas" galaxies and Lyman-alpha galaxies at z~0.3 and z~2.3 in the M-Z and L-Z relations and their morphologies. The G-M_{20} morphology analysis shows that 10 out of 11 show disturbed morphology, even as the star-forming regions are compact. These galaxies may be intrinsically metal poor, being at early stages of formation, or the low metallicities may be due to gas infall and accretion due to mergers.Comment: 24 pages with 7 figure

Metabolic and hormonal acclimation to heat stress in domesticated ruminants

Environmentally induced periods of heat stress decrease productivity with devastating economic consequences to global animal agriculture. Acclimatization is a process by which animals adapt to environmental conditions and engage behavioral, hormonal and metabolic changes that are characteristics of either acclimatory homeostasis or homeorhetic mechanisms used by the animals to survive in a new ‘physiological state’. These physiological modifications alter nutrient partitioning and may prevent heat-stressed lactating cows from recruiting glucose-sparing mechanisms. How these metabolic changes are initiated and regulated is not known. A better understanding of the adaptations enlisted by ruminants during heat stress is necessary to enhance the likelihood of developing strategies to simultaneously improve heat tolerance and increase productivity. Periodo prolungati di stress da caldo severo inducono effetti negative sulla produzione con conseguenze devastanti sulla economia del comparto agro-zootecnico. L’acclimatamento è un processo attraverso cui gli animali si adattano alla variazione delle condizioni ambientali modificando il loro comportamento e variano l’equilibrio ormonale e metabolico con meccanismi di tipo sia omeostatico sia omeoretico con lo scopo di sopravvivere alle nuove condizioni raggiungendo un nuovo stato fisiologico. Queste modificazioni fisiologiche alterano la ripartizione dei nutrienti e possono essere responsabili di una maggiore e diverso utilizzo del glucosio. Come queste variazioni e adattamenti metabolici hanno inizio non è ancora ben noto. Una migliore comprensione dei meccanismi di adattamento dei ruminanti alle condizioni di stress da caldo, permetterà di sviluppare strategie per contemporaneamente migliorare la termo tolleranza e la produttività di soggetti esposti a condizioni stressanti