Hispanic Students in High School and College: Two Views of a Continuing Challenge

Personas Mexicanas: Chicano High Schoolers in a Changing Los Angeles. James Diego Vigil. New York: Harcourt Brace College Publishers, 1997. 160 pp.
The Struggle of Latino/Latina University Students: In Search of a liberating Education. Felix M. Padilla. New York Routledge, 1997. 245 pp.     

Fat Storage-inducing Transmembrane Protein 2 Is Required for Normal Fat Storage in Adipose Tissue

Triglycerides within the cytosol of cells are stored in a phylogenetically conserved organelle called the lipid droplet (LD). LDs can be formed at the endoplasmic reticulum, but mechanisms that regulate the formation of LDs are incompletely understood. Adipose tissue has a high capacity to form lipid droplets and store triglycerides. Fat storage-inducing transmembrane protein 2 (FITM2/FIT2) is highly expressed in adipocytes, and data indicate that FIT2 has an important role in the formation of LDs in cells, but whether FIT2 has a physiological role in triglyceride storage in adipose tissue remains unproven. Here we show that adipose-specific deficiency of FIT2 (AF2KO) in mice results in progressive lipodystrophy of white adipose depots and metabolic dysfunction. In contrast, interscapular brown adipose tissue of AF2KO mice accumulated few but large LDs without changes in cellular triglyceride levels. High fat feeding of AF2KO mice or AF2KO mice on the genetically obese ob/ob background accelerated the onset of lipodystrophy. At the cellular level, primary adipocyte precursors of white and brown adipose tissue differentiated in vitro produced fewer but larger LDs without changes in total cellular triglyceride or triglyceride biosynthesis. These data support the conclusion that FIT2 plays an essential, physiological role in fat storage in vivo.     

Proliferating cell nuclear antigen (PCNA) as a proliferative marker during embryonic and adult zebrafish hematopoiesis

We investigated the expression of proliferative cell nuclear antigen (PCNA) in zebrafish to delineate the proliferative hematopoietic component during adult and embryonic hematopoiesis. Immunostaining for PCNA and enhanced green fluorescence protein (eGFP) was performed in wild-type and fli1-eGFP (endothelial marker) and gata1-eGFP (erythroid cell marker) transgenic fish. Expression of PCNA mRNA was examined in wild-type and chordin morphant embryos. In adult zebrafish kidney, the renal tubules are surrounded by endothelial cells and it is separated into hematopoietic and excretory compartments. PCNA was expressed in hematopoietic progenitor cells but not in mature neutrophils, eosinophils or erythroid cells. Some PCNA+ cells are scattered in the hematopoietic compartment of the kidney while others are closely associated with renal tubular cells. PCNA was also expressed in spermatogonial stem cells and intestine crypts, consistent with its role in cell proliferation and DNA synthesis. In embryos, PCNA is expressed in the brain, spinal cord and intermediate cell mass (ICM) at 24 h-post fertilization. In chordin morphants, PCNA is significantly upregulated in the expanded ICM. Therefore, PCNA can be used to mark cell proliferation in zebrafish hematopoietic tissues and to identify a population of progenitor cells whose significance would have to be further investigated.     

Telemetric monitoring of fetal blood pressure and heart rate in the freely moving pregnant sheep: a feasibility study

Remote telemetric monitoring of fetal haemodynamics in pregnant sheep would allow unrestricted animal movement, minimize suffering and distress, and improve animal welfare, while enhancing the quality of data collected. This may also be useful in clinical practice following fetal surgery. Using an open fetal surgical technique at approximately two-thirds of gestation, we implanted the catheter of a D70-PCTP haemodynamic telemetric device (Data Sciences International, Tilburg, The Netherlands) into the carotid artery of the fetal sheep (n = 4). The attached transmitter was secured to the posterior aspect of the maternal anterior abdominal wall. Two receivers, with a range of 1 m each, were sited in an 11 m2 sheep enclosure to maximize animal freedom while allowing continuous monitoring of the ewe. The receivers were connected by cable to a nearby computer. In the first two procedures, both fetuses died eight and 12 days after surgery, and the catheter tip was observed to be lying in the bicarotid trunk. In the next two procedures the catheter tip was threaded further upstream from the insertion point, in an attempt to reach the fetal aorta, and both fetuses survived until the scheduled postmortem examination at the end of pregnancy. After catheter implantation, fetal blood pressure (BP) and heart rate (HR) were successfully recorded continuously for seven days and then hourly per day for a further three weeks. The fetal BP and HR values were in the normal range for healthy sheep fetuses.     

Impact of temperature on Na2Sr(PO4)F:Eu3+ phosphor

In this article, we report the synthesis of Na₂Sr_1‐x(PO₄)F:Eu_x phosphor via a combustion method. The influence of different annealing temperatures on the photoluminescence properties was investigated. The phosphor was excited at both 254 and 393 nm. Na₂Sr_1‐x(PO₄)F:Eu_x³⁺ phosphors emit strong orange and red color at 593 and 612 nm, respectively, under both excitation wavelengths. Na₂Sr_1‐x(PO₄)F:Eu_x³⁺ phosphors annealed at 1050°C showed stronger emission intensity compared with 600, 900 and 1200°C. Moreover, Na₂Sr_1‐x(PO₄)F:Eu_x³⁺ phosphor was found to be more intense when compared with commercial Y₂O₃:Eu³⁺ phosphor. Copyright © 2013 John Wiley & Sons, Ltd.     

Selection of suitable housekeeping genes for expression analysis in glioblastoma using quantitative RT-PCR

Background  

Considering the broad variation in the expression of housekeeping genes among tissues and experimental situations, studies using quantitative RT-PCR require strict definition of adequate endogenous controls. For glioblastoma, the most common type of tumor in the central nervous system, there was no previous report regarding this issue.     

Genomic analysis of the relationship between gene expression variation and DNA polymorphism in Drosophila simulans

Background

Understanding how DNA sequence polymorphism relates to variation in gene expression is essential to connecting genotypic differences with phenotypic differences among individuals. Addressing this question requires linking population genomic data with gene expression variation.

Results

Using whole genome expression data and recent light shotgun genome sequencing of six Drosophila simulans genotypes, we assessed the relationship between expression variation in males and females and nucleotide polymorphism across thousands of loci. By examining sequence polymorphism in gene features, such as untranslated regions and introns, we find that genes showing greater variation in gene expression between genotypes also have higher levels of sequence polymorphism in many gene features. Accordingly, X-linked genes, which have lower sequence polymorphism levels than autosomal genes, also show less expression variation than autosomal genes. We also find that sex-specifically expressed genes show higher local levels of polymorphism and divergence than both sex-biased and unbiased genes, and that they appear to have simpler regulatory regions.

Conclusion

The gene-feature-based analyses and the X-to-autosome comparisons suggest that sequence polymorphism in cis-acting elements is an important determinant of expression variation. However, this relationship varies among the different categories of sex-biased expression, and trans factors might contribute more to male-specific gene expression than cis effects. Our analysis of sex-specific gene expression also shows that female-specific genes have been overlooked in analyses that only point to male-biased genes as having unusual patterns of evolution and that studies of sexually dimorphic traits need to recognize that the relationship between genetic and expression variation at these traits is different from the genome as a whole.     

Effect of Moringa oleifera leaves on hematological profile of fluorosis affected rats

Fluorosis is a metabolic disease that is endemic in nearly 25 countries with India being one of the most affected. It primarily affects the bone and the teeth. Moringa oleifera (MO) leaves are known to reduce the effect of fluorosis on various tissues. Therefore, it is of interest to document the effect of Moringa oleifera leaves on the hematological profile of fluorosis affected rats. Twenty four Sprague Dawley rats were housed two per cage in a room with 12 hours light and 12 hours dark cycle. The rats were allowed to adjust to the laboratory environment for about one to two weeks before the beginning of the study. This study reveals that MO leaves is effective in reducing the plasma fluoride content. It also helps in improving the Hb % and RBC count in fluorosis affected rats. Data shows that Moringa olifera leaves powder is effective in reducing the plasma fluoride content. It also helps in improving the Hemoglobin percentage & Red Blood Cell count in fluorosis affected rats.     

Enhancement in leghemoglobin content of root nodules by exclusion of solar UV-A and UV-B radiation in soybean

The impact of exclusion of solar UV-B (280–320 nm) and UV-A+B (280–400 nm) radiation on the root nodules was studied in soybean(Glycine max var. MACS 330). Soybean plants were grown in the tropical region of Indore (Latitude-22.4°N), India under field conditions in metal cages covered with polyester exclusion filters that specifically cut off UV-B (<320 nm) and UV-A+B (<400 nm) radiation; control plants were grown under ambient solar radiation. Leghemoglobin content was analyzed in the root nodules on the 50^th day after emergence of seedlings. Exclusion of UV radiations significantly enhanced the leghemoglobin content in the nodules on fresh weight basis; 25% and 45% higher amount of leghemoglobin were present in the nodules after the exclusion of UV-B and UV-A+B radiation respectively. Analysis by native and SDS-PAGE showed high intense bands of leghemoglobin after the exclusion of UV-A+B as compared to control. Exclusion of UV radiation also enhanced the growth of roots as well as aerial parts of the plants. UV Exclusion increased nodulation by increase in the number and size of nodules. The results are discussed in the light of advantage of exclusion for enhancing protein/nitrogen content in the plants.