Ring graphs and complete intersection toric ideals

We study the family of graphs whose number of primitive cycles equals its cycle rank. It is shown that this family is precisely the family of ring graphs. Then we study the complete intersection property of toric ideals of bipartite graphs and oriented graphs. An interesting application is that complete intersection toric ideals of bipartite graphs correspond to ring graphs and that these ideals are minimally generated by Groebner bases. We prove that any graph can be oriented such that its toric ideal is a complete intersection with a universal Groebner basis determined by the cycles. It turns out that bipartite ring graphs are exactly the bipartite graphs that have complete intersection toric ideals for any orientation.Comment: Discrete Math., to appea

SOCIAL WORKERS FOSTERING HIGHER EDUCATION WITHIN FOSTER YOUTH

The following research study examines foster youth and higher education, specifically focusing on the roles social workers do or might play in helping foster youth pursue higher education. The literature suggests that child welfare agencies have implemented programs for foster youth to be able pursue a higher education and for social workers to assist with the process, to improve foster youths’ educational outcomes. However, there continues to be a gap between foster youths’ aspirations and achievements. This study uses a qualitative design, using in-depth interviews with social workers in Southern California. A snowball sampling method was used to recruit participants, including using personal connections of the researchers to identify potential social worker participants and then asking each participant to nominate an additional social worker participant. This study interviewed 10 social workers who have previously worked or are working for the child welfare system. During the interviews the researchers were asked about their assistance in providing youth with information regarding college and university programs that support foster youth, as well as their knowledge of resources to give to the foster youth students. The researchers also asked about the preparation process social workers use with youth applying for admission, financial aid, grants, and scholarships. Upon analyzing the data, three common themes emerged from the interviews of the participants. The three common themes included barriers that foster youth experience in their lives, such as emotional trauma that remains unresolved and finding stability in a placement home and in the relationships they form. The second theme found was the complexity of the child welfare social worker’s role. The final theme that emerged from the analysis of the data is that the focus is not on education for foster youth, this involved obstacles such as a lack of mentorship for the foster youth and a knowledge of resources that is limited in social workers. This research study examines social workers’ perceptions of their roles in supporting foster youth pursue higher education. The major implications of this study are that there is not enough training to better prepare social workers to working with foster youth in helping them achieve a higher education. Another implication is that social workers defined their role in child welfare as being too impacted by the high number of cases that they carry, that they cannot take time to mentor foster youth the way they would like to. It is recommended that the state of California reanalyze their long term outcomes of foster youth if they were to have better mentoring from social workers. This could be made possible if, potentially, social workers were assigned a lower number of cases to take more time and produce a higher quality of work with each individual foster youth student. This study is significant because it may help identify improvements in social work training, education, programs, and policies in order to assist foster youth in achieving higher education

La reforma electoral...un fraude

Después de diez arduos meses de debate y de intentos de alianza entre los partidos, se aprueba la reforma electoral, en donde los puntos debatidos fueron: el sistema electoral, la conformación de la Cámara de Diputados y la Asamblea de Representantes del Distrito Federal

A note on affine toric varieties

AbstractLet k be an arbitrary field and Γ a toric set in the affine space Akn given parametrically by monomials. Using linear algebra we give necessary and sufficient conditions for Γ to be an affine toric variety, and show some applications

Spatial dispersion in Casimir forces: A brief review

We present the basic principles of non-local optics in connection with the calculation of the Casimir force between half-spaces and thin films. At currently accessible distances $L$, non-local corrections amount to about half a percent, but they increase roughly as 1/L at smaller separations. Self consistent models lead to corrections with the opposite sign as models with abrupt surfaces.Comment: Proceedings of QFEXT05, Barcelona, Sept. 5-9, 200

La crisis de la deuda

El trabajo reseña la evolución del endeudamiento externo mexicano durante el periodo de 1970 a 1988, centrándose en las negociaciones efectuadas por el gobierno durante la década de la llamada "crisis de la deuda". En 1970 la deuda total a largo plazo, pública y privada, ascendía a 5.9 mdd, para 1975 ésta sumaba 18.4 mdd y para 1988 la deuda externa llegaba a rebasar los 100.0 mdd correspondiente a más de 80.0 mdd al sector publico y 7.0 mdd al sector privado