Cultural Competence Development, Critical Service Learning, and Latino/a Youth Empowerment: A Qualitative Case Study

As universities create service-learning programs, educators are experimenting with pedagogical approaches that enhance learning outcomes while benefiting communities. We present a qualitative case study of a radio-based, service-learning program, grounded in a Freirean foundation and aimed at developing the cultural competence and sense of citizenship of undergraduate students while empowering working-class high school Latino/a students. Undergraduate students benefited the most from the program; they enhanced their cultural competence skills, awareness of social issues, and sense of civic responsibility. Latino/a high school students who stayed in the program for at least a year developed self-confidence, self-esteem, and a sense of self-efficacy

Mid-Cretaceous paleoenvironmental changes in the western Tethys

We present a continuous record of surface water temperature and fertility variations through the latest Barremian-Cenomanian interval (ca. 27 Myr) based on calcareous nannofossil abundances from the western Tethys. The nannofossil temperature index, calibrated with TEX86 sea surface temperatures, suggests that warmest (34-36 \ub0C) conditions were reached during oceanic anoxic event (OAE) 1a onset, the Aptian-Albian boundary interval hyperthermals (113, Kilian level and Urbino level OAE 1b) and during a ca. 4 Myr long phase in the middle Albian. Coolest temperatures (29 \ub0C) correspond instead to the late Aptian. Generally warm conditions characterized the Albian followed by a progressive cooling trend that started in the latest Albian (at the Marne a Fucoidi-Scaglia Bianca Formation transition). Temperate conditions occurred in the Cenomanian with frequent short-term variations highlighted by abundance peaks of the cold-water nannofossil species E. floralis and R. parvidentatum. Mid-Cretaceous surface water fertility was rather fluctuating and mostly independent from climatic conditions as well as from black shales intervals. Intense warming and fertility spikes were systematically associated only with black shales of OAE 1a and of the Aptian-Albian boundary hyperthermals. The Albian-Cenomanian rhythmic black shales are, in fact, associated with varying long-term climatic and fertility conditions. The similarity of western Tethys climatic and fertility fluctuations during OAE 1a, OAE 1b, the middle Albian and OAE 1d with nannofossil-based records from other basins indicated that these paleoenvironmental conditions were affecting the oceans at supra-regional to global scale

Localization of hepatocyte growth factor and Its receptor met in endocrine cells and related tumors of the gut and pancreas: an immunohistochemical study

Hepatocyte growth factor (HGF), a stimulator of angiogenesis and cell migration, regulates the growth of a wide variety of cells by binding to its high-affinity receptor met and is involved in the growth and aggressiveness of several tumors. In this study we investigated the expression of HGF and met in normal endocrine cells and related neoplasms of the gut and pancreas to verify their possible role in tumor pathogenesis, growth, and aggressiveness. Normal tissues and 60 different endocrine tumors were immunostained using specific antibodies directed against HGF, met, and various hormones. HGF immunoreactivity (IR) was found in antroduodenal G cells, rectal enterochromaffin (EC) cells, and pancreatic A and B cells, whereas met IR was detected in antral EC and C cells, and in pancreatic B cells; 46 of 60 tumors examined were positive for HGF, and they were mainly represented by ECL-, EC-, and L-cell neoplasms. met IR was identified in 50/60 tumors of various phenotypes. HGF and met coexpression was found in 42/60 cases, most of which were represented by EC-cell tumors. HGF/met coexpression was significantly more frequent in ileocolonic EC-cell tumors, which in the majority of cases were malignant, than in appendiceal EC-cell tumors, which were all benign. Our results demonstrated, for the first time, that HGF and met are specifically distributed in normal gut and pancreatic endocrine cells and, in addition, suggest that HGF and met may be implicated as autocrine/paracrine factors regulating the growth of gastroenteropancreatic endocrine tumors, mainly of ileocolonic EC-cell carcinoid

Virtually Abelian Quantum Walks

We introduce quantum walks on Cayley graphs of non-Abelian groups. We focus on the easiest case of virtually Abelian groups, and introduce a technique to reduce the quantum walk to an equivalent one on an Abelian group with coin system having larger dimension. We apply the technique in the case of two quantum walks on virtually Abelian groups with planar Cayley graphs, finding the exact solution.Comment: 10 pages, 3 figure

Calcareous nannofossils as tracers of paleoCO2

The Cretaceous has been characterized by intervals of super-greenhouse climate and profound environmental perturbations, including the early Aptian Oceanic Anoxic Event (OAE 1) a and the latest Cenomanian OAE 2 being episodes of widespread organic matter burial in oxygen-depleted oceans. The OAE 1a and OAE 2 are thought to be related to the emplacement of the Ontong Java Plateau and the Caribbean Plateau, respectively. The volcanic acrivity of these Large Igneous Provinces (LIPs) introduced in the atmosphere a large amount of CO2 with consequent impact on biota, climate and ocean chemistry. The perturbations of the C cycle are traced in the C isotopic record which shows a negative shift at the beginning of OAE 1a followed by a positive excursion, and a large positive anomaly marking the OAE 2. In this study, we intended to detected if and how these changes in pCO2 affected the biogenic carbonate production of calcareous nannoplankton. Coccolithophore algae are in fact extremely sensitive to changes in physical and chemical conditions of the oceans and laboratory experiments on living forms indicate that coccolith type, abundance and degree of mineralization depend on chemical-physical-trophic conditions of water as well as on pCO2. Our data revealed the presence of dwarf/malformed coccoliths during OAE 1a and OAE 2 interpreted to be the response of some coccolithophore species to increased surface-water acidification, thus providing indication of intervals of excess CO2. Following these observations, that suggest that past calcareous nannoplankton probably responded similarly to extant coccolithophores under fluctuating CO2, we reconstructed nannofossil calcite paleofluxes during the Aptian and used them to calculate paleoCO2. Calcite production resulted to be severly affected during OAE 1a, when the highest CO2 concetrations of the Aptian were reached under the most intense phase of Ontong Java. During the middle-late Aptian, paleofluxes were then characterized by fluctuations, suggestive for variable paleoCO2 depending on the interplay between CO2 emissions and uptake