MARIA SOLEDAD PEREZ DIAZ - Academia.edu (original) (raw)
Papers by MARIA SOLEDAD PEREZ DIAZ
Language and Literacy, 2012
This case study examines new literacy opportunities and practices of 28 Latino/a children from gr... more This case study examines new literacy opportunities and practices of 28 Latino/a children from grades one to seven in a South Texas colonia, or unincorporated area. Data sources were 24-hour literacy logs, two rounds of interviews, and participant observations. The children reported limited school work related to digital literacies; the technology they accessed outside of school focused on entertainment, communication with friends, and mostly non-challenging video games. We discuss participants’ ingenious ways of circumventing any lack of access, their underlying social practices of community sharing, and Thirdspace possibilities of the tutorial center that respondents attended.
Tlatemoani, 2012
Los contaminantes actúan negativamente sobre los seres vivos. Así, la ecotoxicología se ha encarg... more Los contaminantes actúan negativamente sobre los seres vivos. Así, la ecotoxicología se ha encargado del estudio de la contaminación, su origen, destino y efecto sobre los seres vivos y ecosistemas. Los métodos ecotoxicológicos son útiles para determinar el efecto de los contaminantes en la salud del suelo y para evaluar la eficiencia de las medidas de remediación emprendidas para sanearlo. Entre los contaminantes cuyos efectos pueden ser evaluados con las pruebas ecotoxicológicas se encuentran los metales pesados, plaguicidas e hidrocarburos del petróleo, compuestos altamente tóxicos que pueden provocar cáncer en el ser humano. Los efectos de los
This case study reveals a Spanish language marginalization in a South Texas community of mostly L... more This case study reveals a Spanish language marginalization in a South Texas community of mostly Latinos, who are the fastest growing group in the U.S. (Colombi & Roca, 2003); furthermore, approximately 77% of English language learners (ELLs) have Spanish as their heritage language (Hopstock & Stephenson, 2003). Nevertheless, ELLs do not receive much academic literacy support in their first language in many schools (Zehler et al., 2003). Thus, out-of-school social practices play an important role on maintaining a native language (e.g., Burrows-Goodwill, 2009; Reyes, 2006). However, researchers have not explored this phenomenon in Texas border colonias, or unincorporated areas where city services are non-existent (U.S. Department of Housing and Urban Development, 2005) and where almost half of residents live below the poverty line (U.S. Census Bureau, 2000). This case study examined Spanish language use in the Texas border colonia of El Palmar (pseudonym). I utilized U.S. Census data, linguistic landscape analysis of the neighborhood, participant observations, language use surveys, language logs, and viii interviews to determine the extent that bilingualism and biliteracy have developed in El Palmar and the factors leading to language maintenance or shift in this colonia. I used the
Lecture Notes in Computer Science, 1999
ABSTRACT Quantification of regularity of cell sizes and the spatial arrangement of cells in corne... more ABSTRACT Quantification of regularity of cell sizes and the spatial arrangement of cells in corneal endotheliums becomes of a great importance associated to stress situations such as cataract surgery, corneal transplantation or implantation of intra-ocular lenses. A new index of regularity of the spatial distribution of cell sizes in corneal endotheliums is proposed. The corneal endothelium is described by means of a spatial marked point pattern (the cell centroids marked with the cell areas). The hypothesis of no dependency between mark and locations is tested by a Monte Carlo test. The new index is the p-value of the test validating the hypothesis. Pairs of endotheliums from different eyes of the same person are compared in terms of the traditional measures (density, hexagonality and coefficient of variation) and the new index. Results show how the index proposed can discriminate subtle morphological changes that cannot be detected by the commonly used indices.
Journal of Latinos and Education, 2013
This qualitative study examines the literacy and language beliefs and practices of 28 Latino/a ch... more This qualitative study examines the literacy and language beliefs and practices of 28 Latino/a children from Grades 1-7 in a South Texas colonia, or unincorporated area. Instruments included staff surveys and participating children's 24-hr reading logs, interviews, and participant observations. The children had limited access to books, mostly during the summer, and most reported having negative attitudes toward reading. They also showed a preference to read in English rather than in Spanish. Implications of access to printed literacy and the language shift of colonia children to English are also discussed.
2009 11th International Conference on Transparent Optical Networks, 2009
This paper introduces a new strategy to provide QoS in IP/OBS networks, using Routing with Priori... more This paper introduces a new strategy to provide QoS in IP/OBS networks, using Routing with Prioritization Based on Statistics (RPBS). This proposal uses the feedback scheme in optical networks to provide statistical knowledge with the objective of finding a suitable route for reach each destination from a specific source node, with more chance of success. This yields a twofold outcome. First, the losses can be reduced due to the statistics. Second, the delays are also reduced compare with other methods based on feedback scheme. These two improvements allow better QoS provision, supporting class differentiation and more efficient resources utilization. The benefits of this proposal are compared against existent alternatives by simulation.
International Journal of Computer Vision, 1999
The subject of this paper is to propose and test a set of numerical descriptors of 2D binary plan... more The subject of this paper is to propose and test a set of numerical descriptors of 2D binary planar shapes. Given a shape, A, the transformations of A with a given mathematical morphological operation and different structuring elements are considered. The measures of this family of transformed sets provide a numerical description of the original set A. These descriptors are very robust against noise and maintain a reasonable discriminatory power. The robustness against different levels of contour degradation is tested by simulation. Starting with a clean (without noise) set, , it is assumed that the observed set, A, is a noisy version (with contour degradation) of. The performance of the descriptors, when they are used to compare different shapes or shapes from a scene with models, is studied and compared with related descriptors based on the granulometric analysis of the original set, which are the closest previous alternative to our approach in the literature.
2007 4th Ieee International Symposium on Biomedical Imaging : Macro to Nano, Vols 1-3, 2007
Total internal reflection fluorescence microscopy (TIRPM) allows to image endocytosis in-vivo wit... more Total internal reflection fluorescence microscopy (TIRPM) allows to image endocytosis in-vivo with exquisite spatial-temporal resolution. Regions covered by endocytic fluorescent-tagged proteins overlap forming random clumps of different sizes, shapes and durations. We model the areas associated with endocytic events by means of temporal random sets and estimate the duration distribution of endocytic events from the covariance function. A simulation study
Tetrahedron, 2002
ÐA comparison of the more active polyether toxins which are selective activators of voltage-sensi... more ÐA comparison of the more active polyether toxins which are selective activators of voltage-sensitive sodium channels (VSSC), indicate that these molecules are mostly¯at, with a hinge part around the middle of the molecules and a large curvature at one of the ends. Assuming that the receptor is topographically complementary to the active molecules, from the result reported here we could conclude, that the speci®c requirements of the receptor region can be achieved by synthetic polyether models based on exclusive participation of oxane/ oxepane moieties. A new convergent approach to give oxepene rings via double reduction of methyl diacetals is explored. In searching for biological models to further characterize Na 1 channels, our studies show that different voltage-dependent Na 1 channels are expressed in the rat uterus and activated by brevetoxin-B. However, selected compound models synthesized in this work, failed to inhibit or activate Na 1 channel function.
International Journal of Pattern Recognition and Artificial Intelligence, 2002
This paper presents a method for detecting abnormalities in spatial arrangements of cells within ... more This paper presents a method for detecting abnormalities in spatial arrangements of cells within any tissue that can be described by different sets of relevant points. The method has been applied to the detection of subtle abnormalities in corneal endothelia. Images of this type of tissue can be characterized by two types of points: cell centroids and triple points associated with the apical intersections as it was proposed by Díaz.7 Both types of points jointly considered are modeled using a bivariate spatial point process; then a statistical analysis based on certain distributional descriptors proposed by Doguwa4,9 is carried out to discriminate severe and subtle abnormalities from controls. According to the results, the method constitutes a valid alternative to currently used techniques, which involve statistical descriptions of cell density, cell area and hexagonality, that fail in the detection of these subtle abnormalities.
![Research paper thumbnail of Corrigendum to “Th1 and Th2 indices of the immune response in pigs vaccinated against Taenia solium cysticercosis suggest various host immune strategies against the parasite” [Vet. Immunol. Immunopathol. 93 (2003) 81–90]](https://attachments.academia-assets.com/92430237/thumbnails/1.jpg)
](Veterinary Immunology and Immunopathology, 2005
Corrigendum to ''Th1 and Th2 indices of the immune response in pigs vaccinated against Taenia sol... more Corrigendum to ''Th1 and Th2 indices of the immune response in pigs vaccinated against Taenia solium cysticercosis suggest various host immune strategies against the parasite'' [Vet. Immunol. Immunopathol. 93 (2003) 81-90]
Veterinary Immunology and Immunopathology, 2003
Kinetics of the production of serum antibody levels and Th1 (IL-2, IFN-g) and Th2 (IL-4, IL-10) c... more Kinetics of the production of serum antibody levels and Th1 (IL-2, IFN-g) and Th2 (IL-4, IL-10) cytokines was studied in five pigs vaccinated with a synthetic tri-peptide vaccine (S3Pvac) against Taenia solium, a vaccine that has been shown protects pigs against naturally acquired infection. Healthy pigs of mixed genetic background, similar to those bred in rural villages of Mexico, were vaccinated with S3Pvac or with adjuvant alone, kept in sanitary conditions and bled at different times after vaccination to study the development of their specific immune response. Peripheral blood mononuclear cells (PBMCs) of vaccinated pigs showed a significant increment in the production of Th1 cytokines (IL-2 and IFN-g) but not of Th2 cytokines (IL-4 and IL-10) after specific PBLs stimulation with all the individual peptides. A Th1-inclined cytokine profile leading to an exacerbated local inflammation at the early installation stage of the cysticercus may possibly interfere with their successful establishment in the serum antibodies against total cysticercus antigens and against each of the three different peptides comprising S3Pvac were detected 7-51 days after vaccination. Antibodies against GK-1 interfered with the cysticerci development into intestinal tapeworms in prednisolone-treated hamsters. The sub-lethal crippling effect of anti-GK-1 antibodies upon cysticerci indicates to a therapeutic application of S3Pvac in infected pigs having potential epidemiological consequences, as it could aid in decreasing the number of tapeworms expected to develop from the few cysticerci that survive in the vaccinated pigs.
Tetrahedron Letters, 1991
... A STEREOSELECTIVE ENTRY INTO C g OXEPANE SUBUNITS Dleuterio Alvarez, M. TeresaDiaz, Ricardo P... more ... A STEREOSELECTIVE ENTRY INTO C g OXEPANE SUBUNITS Dleuterio Alvarez, M. TeresaDiaz, Ricardo Perez and Julio D. Martin* (X14114039 91 3.00+.00 Pergamon Press ... REFERENCES AND NOTES 1. For an excellent coverage of the field, see: DJ Faulkner, Nat.Prod. ...
Tetrahedron Letters, 1996
An efficient strategy for the synthesis of trans-fused oxabicyclic systems involving thioannulati... more An efficient strategy for the synthesis of trans-fused oxabicyclic systems involving thioannulation followed by a Ramberg-Bäcklund olefination as the key step is described. ... An efficient strategy for the synthesis of trans-fused oxabicyclic systems involving thioannulation followed by a ...
Nutrition Research, 2002
In order to study the effect of low protein content in maternal diet on kidney development of pup... more In order to study the effect of low protein content in maternal diet on kidney development of pups, Wistar female rats were fed isocaloric diets containing 4%, 8% or 20% protein throughout pregnancy and transferred to a commercial diet during lactation. Birth weight of pups was significantly lower (p Ͻ 0.05) only when mothers were fed 4% protein diet. Offspring of the 3 groups of dams were weaned on the 21 st day and sacrificed 7 days later. Significant reduction (p Ͻ 0.05) in the number of glomeruli but not in their diameter, glomerular sclerosis index or interstitial fibrosis index were found in the pups born to mothers fed both low protein diets. Plasma creatinine was significantly higher (p Ͻ 0.05) in offspring of both low protein diets, while homocysteine only in that born to the 4% protein fed mothers. So, our results are consistent with the hypothesis that maternal undernutrition can determine a reduction in nephron number and hence influence adult cardiovascular and renal diseases.
The Journal of Organic Chemistry, 1996
A successful design for the construction of trans-fused medium-size cyclic ethers is described. T... more A successful design for the construction of trans-fused medium-size cyclic ethers is described. The key features of the synthesis are as follows: (i) intramolecular oxirane ring expansion in cycloalkenes to give bridged oxabicyclic systems and (ii) linear, one-or two-directional synthetic operations which generate external oxocycles in single reaction steps. The general approach involves the intramolecular addition of a stable y-alkoxy-substituted allylstannane to an aldehyde carbonyl group, and the entire reaction is conducted in a one-pot process which includes the following: (i) vic-diol fragmentation from the bridged oxabicyclic precursor and (ii) Lewis acid-induced cyclization of the resulting aldehyde allylic tin system. While the present strategy was mostly developed around racemic models, the potential for adoption of enantioselective features is immediate. The versatility, scope, limitations, and potential applications of the present technology are discussed in detail.
Journal of Mathematical Imaging and Vision, 2010
Recent advances in microscopy jointly to the development of fluorescent probes have enabled to im... more Recent advances in microscopy jointly to the development of fluorescent probes have enabled to image dynamic processes with very high spatial-temporal resolution, for instance in Cell Biology. In some applications, the segmented areas associated with different events overlap spatially and temporally forming random clumps. In order to study the shape-size features and durations of the events, it is a usual
Journal of Lower Genital Tract Disease, 2007
IEEE/ACM Transactions on Computational Biology and Bioinformatics, 2006
Exocytosis is an essential cellular trafficking process integral to the proper distribution and f... more Exocytosis is an essential cellular trafficking process integral to the proper distribution and function of a plethora of molecules, including transporters, receptors, and enzymes. Moreover, incorrect protein targeting can lead to pathological conditions. Recently, the application of evanescent wave microscopy has allowed us to image the final steps of exocytosis. However, spatio-temporal analysis of fusion of constitutive vesicular traffic with the plasma membrane has not been systematically performed. Also, the spatial sites and times of vesicle fusion have not yet been analyzed together. In addition, more formal tests are required in testing biological hypotheses, rather than visual inspection combined with statistical descriptives. Ripley K-functions are used to examine the joint and marginal behavior of locations and fusion times. Semiautomatic detection and mapping of constitutive fusion sites reveals spatial and temporal clustering, but no dependency between the locations and times of fusion events. Our novel approach could be translated to other studies of membrane trafficking in health and diseases such as diabetes.
Hispanic Journal of Behavioral Sciences, 2012
In this study, we investigate individual-level language shift in a population of Mexican origin L... more In this study, we investigate individual-level language shift in a population of Mexican origin Latinos/as aged 65 and up. By using data from the Hispanic Established Populations for the Epidemiologic Study of the Elderly, we investigate their English language use as the dependent variable in a hierarchical linear model. The microlevel independent continuous variable is their level of contact with “Anglos”; the macrolevel continuous independent variable is the percentage of Mexicans in tract of residence. After accounting for their generational status, other microlevel social and health covariates, and tract-level attributes, we found a direct relationship between contact with Anglos and a “shift” toward more English language use, where as co-ethnic concentration increases, the influence of contact with Anglos decreases. We frame this article with a discussion on language shifting, and explain how co-ethnic concentration may provide the resources for engaging in a language resistance.
Language and Literacy, 2012
This case study examines new literacy opportunities and practices of 28 Latino/a children from gr... more This case study examines new literacy opportunities and practices of 28 Latino/a children from grades one to seven in a South Texas colonia, or unincorporated area. Data sources were 24-hour literacy logs, two rounds of interviews, and participant observations. The children reported limited school work related to digital literacies; the technology they accessed outside of school focused on entertainment, communication with friends, and mostly non-challenging video games. We discuss participants’ ingenious ways of circumventing any lack of access, their underlying social practices of community sharing, and Thirdspace possibilities of the tutorial center that respondents attended.
Tlatemoani, 2012
Los contaminantes actúan negativamente sobre los seres vivos. Así, la ecotoxicología se ha encarg... more Los contaminantes actúan negativamente sobre los seres vivos. Así, la ecotoxicología se ha encargado del estudio de la contaminación, su origen, destino y efecto sobre los seres vivos y ecosistemas. Los métodos ecotoxicológicos son útiles para determinar el efecto de los contaminantes en la salud del suelo y para evaluar la eficiencia de las medidas de remediación emprendidas para sanearlo. Entre los contaminantes cuyos efectos pueden ser evaluados con las pruebas ecotoxicológicas se encuentran los metales pesados, plaguicidas e hidrocarburos del petróleo, compuestos altamente tóxicos que pueden provocar cáncer en el ser humano. Los efectos de los
This case study reveals a Spanish language marginalization in a South Texas community of mostly L... more This case study reveals a Spanish language marginalization in a South Texas community of mostly Latinos, who are the fastest growing group in the U.S. (Colombi & Roca, 2003); furthermore, approximately 77% of English language learners (ELLs) have Spanish as their heritage language (Hopstock & Stephenson, 2003). Nevertheless, ELLs do not receive much academic literacy support in their first language in many schools (Zehler et al., 2003). Thus, out-of-school social practices play an important role on maintaining a native language (e.g., Burrows-Goodwill, 2009; Reyes, 2006). However, researchers have not explored this phenomenon in Texas border colonias, or unincorporated areas where city services are non-existent (U.S. Department of Housing and Urban Development, 2005) and where almost half of residents live below the poverty line (U.S. Census Bureau, 2000). This case study examined Spanish language use in the Texas border colonia of El Palmar (pseudonym). I utilized U.S. Census data, linguistic landscape analysis of the neighborhood, participant observations, language use surveys, language logs, and viii interviews to determine the extent that bilingualism and biliteracy have developed in El Palmar and the factors leading to language maintenance or shift in this colonia. I used the
Lecture Notes in Computer Science, 1999
ABSTRACT Quantification of regularity of cell sizes and the spatial arrangement of cells in corne... more ABSTRACT Quantification of regularity of cell sizes and the spatial arrangement of cells in corneal endotheliums becomes of a great importance associated to stress situations such as cataract surgery, corneal transplantation or implantation of intra-ocular lenses. A new index of regularity of the spatial distribution of cell sizes in corneal endotheliums is proposed. The corneal endothelium is described by means of a spatial marked point pattern (the cell centroids marked with the cell areas). The hypothesis of no dependency between mark and locations is tested by a Monte Carlo test. The new index is the p-value of the test validating the hypothesis. Pairs of endotheliums from different eyes of the same person are compared in terms of the traditional measures (density, hexagonality and coefficient of variation) and the new index. Results show how the index proposed can discriminate subtle morphological changes that cannot be detected by the commonly used indices.
Journal of Latinos and Education, 2013
This qualitative study examines the literacy and language beliefs and practices of 28 Latino/a ch... more This qualitative study examines the literacy and language beliefs and practices of 28 Latino/a children from Grades 1-7 in a South Texas colonia, or unincorporated area. Instruments included staff surveys and participating children's 24-hr reading logs, interviews, and participant observations. The children had limited access to books, mostly during the summer, and most reported having negative attitudes toward reading. They also showed a preference to read in English rather than in Spanish. Implications of access to printed literacy and the language shift of colonia children to English are also discussed.
2009 11th International Conference on Transparent Optical Networks, 2009
This paper introduces a new strategy to provide QoS in IP/OBS networks, using Routing with Priori... more This paper introduces a new strategy to provide QoS in IP/OBS networks, using Routing with Prioritization Based on Statistics (RPBS). This proposal uses the feedback scheme in optical networks to provide statistical knowledge with the objective of finding a suitable route for reach each destination from a specific source node, with more chance of success. This yields a twofold outcome. First, the losses can be reduced due to the statistics. Second, the delays are also reduced compare with other methods based on feedback scheme. These two improvements allow better QoS provision, supporting class differentiation and more efficient resources utilization. The benefits of this proposal are compared against existent alternatives by simulation.
International Journal of Computer Vision, 1999
The subject of this paper is to propose and test a set of numerical descriptors of 2D binary plan... more The subject of this paper is to propose and test a set of numerical descriptors of 2D binary planar shapes. Given a shape, A, the transformations of A with a given mathematical morphological operation and different structuring elements are considered. The measures of this family of transformed sets provide a numerical description of the original set A. These descriptors are very robust against noise and maintain a reasonable discriminatory power. The robustness against different levels of contour degradation is tested by simulation. Starting with a clean (without noise) set, , it is assumed that the observed set, A, is a noisy version (with contour degradation) of. The performance of the descriptors, when they are used to compare different shapes or shapes from a scene with models, is studied and compared with related descriptors based on the granulometric analysis of the original set, which are the closest previous alternative to our approach in the literature.
2007 4th Ieee International Symposium on Biomedical Imaging : Macro to Nano, Vols 1-3, 2007
Total internal reflection fluorescence microscopy (TIRPM) allows to image endocytosis in-vivo wit... more Total internal reflection fluorescence microscopy (TIRPM) allows to image endocytosis in-vivo with exquisite spatial-temporal resolution. Regions covered by endocytic fluorescent-tagged proteins overlap forming random clumps of different sizes, shapes and durations. We model the areas associated with endocytic events by means of temporal random sets and estimate the duration distribution of endocytic events from the covariance function. A simulation study
Tetrahedron, 2002
ÐA comparison of the more active polyether toxins which are selective activators of voltage-sensi... more ÐA comparison of the more active polyether toxins which are selective activators of voltage-sensitive sodium channels (VSSC), indicate that these molecules are mostly¯at, with a hinge part around the middle of the molecules and a large curvature at one of the ends. Assuming that the receptor is topographically complementary to the active molecules, from the result reported here we could conclude, that the speci®c requirements of the receptor region can be achieved by synthetic polyether models based on exclusive participation of oxane/ oxepane moieties. A new convergent approach to give oxepene rings via double reduction of methyl diacetals is explored. In searching for biological models to further characterize Na 1 channels, our studies show that different voltage-dependent Na 1 channels are expressed in the rat uterus and activated by brevetoxin-B. However, selected compound models synthesized in this work, failed to inhibit or activate Na 1 channel function.
International Journal of Pattern Recognition and Artificial Intelligence, 2002
This paper presents a method for detecting abnormalities in spatial arrangements of cells within ... more This paper presents a method for detecting abnormalities in spatial arrangements of cells within any tissue that can be described by different sets of relevant points. The method has been applied to the detection of subtle abnormalities in corneal endothelia. Images of this type of tissue can be characterized by two types of points: cell centroids and triple points associated with the apical intersections as it was proposed by Díaz.7 Both types of points jointly considered are modeled using a bivariate spatial point process; then a statistical analysis based on certain distributional descriptors proposed by Doguwa4,9 is carried out to discriminate severe and subtle abnormalities from controls. According to the results, the method constitutes a valid alternative to currently used techniques, which involve statistical descriptions of cell density, cell area and hexagonality, that fail in the detection of these subtle abnormalities.
Veterinary Immunology and Immunopathology, 2005
Corrigendum to ''Th1 and Th2 indices of the immune response in pigs vaccinated against Taenia sol... more Corrigendum to ''Th1 and Th2 indices of the immune response in pigs vaccinated against Taenia solium cysticercosis suggest various host immune strategies against the parasite'' [Vet. Immunol. Immunopathol. 93 (2003) 81-90]
Veterinary Immunology and Immunopathology, 2003
Kinetics of the production of serum antibody levels and Th1 (IL-2, IFN-g) and Th2 (IL-4, IL-10) c... more Kinetics of the production of serum antibody levels and Th1 (IL-2, IFN-g) and Th2 (IL-4, IL-10) cytokines was studied in five pigs vaccinated with a synthetic tri-peptide vaccine (S3Pvac) against Taenia solium, a vaccine that has been shown protects pigs against naturally acquired infection. Healthy pigs of mixed genetic background, similar to those bred in rural villages of Mexico, were vaccinated with S3Pvac or with adjuvant alone, kept in sanitary conditions and bled at different times after vaccination to study the development of their specific immune response. Peripheral blood mononuclear cells (PBMCs) of vaccinated pigs showed a significant increment in the production of Th1 cytokines (IL-2 and IFN-g) but not of Th2 cytokines (IL-4 and IL-10) after specific PBLs stimulation with all the individual peptides. A Th1-inclined cytokine profile leading to an exacerbated local inflammation at the early installation stage of the cysticercus may possibly interfere with their successful establishment in the serum antibodies against total cysticercus antigens and against each of the three different peptides comprising S3Pvac were detected 7-51 days after vaccination. Antibodies against GK-1 interfered with the cysticerci development into intestinal tapeworms in prednisolone-treated hamsters. The sub-lethal crippling effect of anti-GK-1 antibodies upon cysticerci indicates to a therapeutic application of S3Pvac in infected pigs having potential epidemiological consequences, as it could aid in decreasing the number of tapeworms expected to develop from the few cysticerci that survive in the vaccinated pigs.
Tetrahedron Letters, 1991
... A STEREOSELECTIVE ENTRY INTO C g OXEPANE SUBUNITS Dleuterio Alvarez, M. TeresaDiaz, Ricardo P... more ... A STEREOSELECTIVE ENTRY INTO C g OXEPANE SUBUNITS Dleuterio Alvarez, M. TeresaDiaz, Ricardo Perez and Julio D. Martin* (X14114039 91 3.00+.00 Pergamon Press ... REFERENCES AND NOTES 1. For an excellent coverage of the field, see: DJ Faulkner, Nat.Prod. ...
Tetrahedron Letters, 1996
An efficient strategy for the synthesis of trans-fused oxabicyclic systems involving thioannulati... more An efficient strategy for the synthesis of trans-fused oxabicyclic systems involving thioannulation followed by a Ramberg-Bäcklund olefination as the key step is described. ... An efficient strategy for the synthesis of trans-fused oxabicyclic systems involving thioannulation followed by a ...
Nutrition Research, 2002
In order to study the effect of low protein content in maternal diet on kidney development of pup... more In order to study the effect of low protein content in maternal diet on kidney development of pups, Wistar female rats were fed isocaloric diets containing 4%, 8% or 20% protein throughout pregnancy and transferred to a commercial diet during lactation. Birth weight of pups was significantly lower (p Ͻ 0.05) only when mothers were fed 4% protein diet. Offspring of the 3 groups of dams were weaned on the 21 st day and sacrificed 7 days later. Significant reduction (p Ͻ 0.05) in the number of glomeruli but not in their diameter, glomerular sclerosis index or interstitial fibrosis index were found in the pups born to mothers fed both low protein diets. Plasma creatinine was significantly higher (p Ͻ 0.05) in offspring of both low protein diets, while homocysteine only in that born to the 4% protein fed mothers. So, our results are consistent with the hypothesis that maternal undernutrition can determine a reduction in nephron number and hence influence adult cardiovascular and renal diseases.
The Journal of Organic Chemistry, 1996
A successful design for the construction of trans-fused medium-size cyclic ethers is described. T... more A successful design for the construction of trans-fused medium-size cyclic ethers is described. The key features of the synthesis are as follows: (i) intramolecular oxirane ring expansion in cycloalkenes to give bridged oxabicyclic systems and (ii) linear, one-or two-directional synthetic operations which generate external oxocycles in single reaction steps. The general approach involves the intramolecular addition of a stable y-alkoxy-substituted allylstannane to an aldehyde carbonyl group, and the entire reaction is conducted in a one-pot process which includes the following: (i) vic-diol fragmentation from the bridged oxabicyclic precursor and (ii) Lewis acid-induced cyclization of the resulting aldehyde allylic tin system. While the present strategy was mostly developed around racemic models, the potential for adoption of enantioselective features is immediate. The versatility, scope, limitations, and potential applications of the present technology are discussed in detail.
Journal of Mathematical Imaging and Vision, 2010
Recent advances in microscopy jointly to the development of fluorescent probes have enabled to im... more Recent advances in microscopy jointly to the development of fluorescent probes have enabled to image dynamic processes with very high spatial-temporal resolution, for instance in Cell Biology. In some applications, the segmented areas associated with different events overlap spatially and temporally forming random clumps. In order to study the shape-size features and durations of the events, it is a usual
Journal of Lower Genital Tract Disease, 2007
IEEE/ACM Transactions on Computational Biology and Bioinformatics, 2006
Exocytosis is an essential cellular trafficking process integral to the proper distribution and f... more Exocytosis is an essential cellular trafficking process integral to the proper distribution and function of a plethora of molecules, including transporters, receptors, and enzymes. Moreover, incorrect protein targeting can lead to pathological conditions. Recently, the application of evanescent wave microscopy has allowed us to image the final steps of exocytosis. However, spatio-temporal analysis of fusion of constitutive vesicular traffic with the plasma membrane has not been systematically performed. Also, the spatial sites and times of vesicle fusion have not yet been analyzed together. In addition, more formal tests are required in testing biological hypotheses, rather than visual inspection combined with statistical descriptives. Ripley K-functions are used to examine the joint and marginal behavior of locations and fusion times. Semiautomatic detection and mapping of constitutive fusion sites reveals spatial and temporal clustering, but no dependency between the locations and times of fusion events. Our novel approach could be translated to other studies of membrane trafficking in health and diseases such as diabetes.
Hispanic Journal of Behavioral Sciences, 2012
In this study, we investigate individual-level language shift in a population of Mexican origin L... more In this study, we investigate individual-level language shift in a population of Mexican origin Latinos/as aged 65 and up. By using data from the Hispanic Established Populations for the Epidemiologic Study of the Elderly, we investigate their English language use as the dependent variable in a hierarchical linear model. The microlevel independent continuous variable is their level of contact with “Anglos”; the macrolevel continuous independent variable is the percentage of Mexicans in tract of residence. After accounting for their generational status, other microlevel social and health covariates, and tract-level attributes, we found a direct relationship between contact with Anglos and a “shift” toward more English language use, where as co-ethnic concentration increases, the influence of contact with Anglos decreases. We frame this article with a discussion on language shifting, and explain how co-ethnic concentration may provide the resources for engaging in a language resistance.