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The Organ Mountains caldera and batholith expose the volcanic and epizonal plutonic record of an Eocene caldera complex. The caldera and batholith are well exposed, and extensive previous mapping and geochemical analyses have suggested a clear link between the volcanic and plutonic sections, making this an ideal location to study magmatic processes associated with caldera volcanism. Here we present high-precision thermal ionization mass spectrometry U-Pb zircon dates from throughout the caldera and batholith, and use these dates to test and improve existing petrogenetic models. The new dates indicate that Eocene volcanic and plutonic rocks in the Organ Mountains formed from ~44 to 34 Ma. The three largest caldera-related tuff units yielded weighted mean Pb/U dates of 36.441 ± 0.020 Ma (Cueva Tuff), 36.259 ± 0.016 Ma (Achenback Park tuff), and 36.215 ± 0.016 Ma (Squaw Mountain tuff). An alkali feldspar granite, which is chemically similar to the erupted tuffs, yielded a synchronous weighted mean Pb/U date of 36.259 ± 0.021 Ma. Weighted mean Pb/U dates from the larger volume syenitic phase of the underlying Organ Needle pluton range from 36.130 ± 0.031 to 36.071 ± 0.012 Ma, and the youngest sample is 144 ± 20 to 188 ± 20 ka younger than the Squaw Mountain and Achenback Park tuffs, respectively. Younger plutonism in the batholith continued through at least 34.051 ± 0.029 Ma. We propose that the Achenback Park tuff, Squaw Mountain tuff, alkali feldspar granite and Organ Needle pluton formed from a single, long-lived magma chamber/mush zone. Early silicic magmas generated by partial melting of the lower crust rose to form an epizonal magma chamber. Underplating of the resulting mush zone led to partial melting and generation of a high-silica alkali feldspar granite cap, which erupted to form the tuffs. The deeper parts of the chamber underwent continued recharge and crystallization for 144 ± 20 ka after the final eruption. Calculated magmatic fluxes for the Organ Needle pluton range from 0.0006 to 0.0030 km/year, in agreement with estimates from other well-studied plutons. The petrogenetic evolution proposed here may be common to many small-volume silicic volcanic systems. [ABSTRACT FROM AUTHOR]

Using an ecological framework this study examines the relationships of micro- (personal characteristics and community commitment), mezzo-(trust and social network) and macro-level factors (social organization involvement and faith-based capital) and civic engagement, in a sample of African Americans males. Two research questions were examined: When micro-level factors are controlled for are macro- and mezzo- level factors predictive of civic engagement (i.e., civic activity behavior and charitable behavior)? What is the relative contribution of faith-based social capital and social organization involvement to civic engagement? African American male participants in the 2000 Social Capital Benchmark Survey provided the data for this study (Saguaro Seminar, 2001). Hierarchical Ordinary Least Squares (OLS) regression was used to address the study's research questions. The findings highlight the importance of social organization involvement and the diversity of African American men's individual's social networks as predictors of their civic engagement. [ABSTRACT FROM AUTHOR]

The T-cell mediated immune responses to the male specific minor histocompatibility antigen H-Y in mice have been studied extensively as a model for immune responses to other weak antigens like tumor antigens or autoantigens. In a recent analysis of the strain distribution of the cytotoxic T-cell (Tc-cell) responsiveness to H-Y, it has been found that genes both within and outside the H-2 complex exert an interactive control. Whereas the H-2 strains all are high responders, independent of their non- H-2 background, other H-2 haplotypes ( d, k, and s) only allow for a response if they are combined with certain non- H- 2 genes. The H- 2-linked immune response genes ( Ir-genes) have been previously mapped to the I and K or D region of the H-2 complex, but the mapping of the non- H- 2 genes has not yet been established. In this study evidence is presented, using recombinant inbred strains and immunoglobulin heavy chain (Igh) congenic strains of mice, to show that there is more than one non- H-2 Ir-gene involved, that the main controlling genes are not linked to the Igh complex, and that at least one non- H-2 Ir-gene is linked to the H-3 region on chromosome 2. This region includes genes for beta-2-microglobulin (β2m), the Ly-mllalloantigen a polymorphic cell surface glycoprotein (Pgp-1), a B-cell specific antigen Ly-4, a transplantation antigen H-3, and genes ( Ir-2) controlling the immune response to Ea-1 and H-13. [ABSTRACT FROM AUTHOR]

To study the effects on the fetus of variations in maternal glucose tolerance, a 25 g rapid intravenous glucose tolerance test was performed at or about 32 weeks gestation in 917 randomly selected nondiabetic women with singleton pregnancies. The results were withheld from the patients and their obstetricians and paediatricians, and no treatment or advice was offered. Fasting plasma glucose and indices of glucose disposal (including a new index which we have termed 'summed glucose') were distributed unimodally, with no evidence of a separate pathological group towards the diabetic end of the distributions. Significant associations were found between maternal glucose metabolism and var ious measures of neonatal nutrition and morbidity, including the incidence of congenital malformations and morbidity related to asphyxia, suggesting that variations within the normal range in maternal glucose metabolism can influence growth and development in the fetus. These relationships were continuous throughout the range of maternal glucose tolerance and were not of predictive value in individual cases. [ABSTRACT FROM AUTHOR]

Culture of L-929 fibroblasts in the presence of phenytoin (2.5-5.0 μg/ml) increased DNA synthesis, as indicated by increased [H]thymidine uptake, while a higher dose (20 μg/ml) inhibited DNA synthesis. In like manner, a low dose of phenytoin (5.0 μg/ml) was effective in increasing inositol 1,4,5-trisphosphate formation while a higher dose (10 μg/ml) tended to inhibit this activity. These data suggest that the formation of inositol phosphate second messengers may play a role in phenytoin-induced fibroblast proliferation and connective tissue growth. [ABSTRACT FROM AUTHOR]

In the version of the paper originally published the current address of author Jeremy T Ross was given incorrectly as Untied Status Marine Corp, 3351 Onslow Drive, Camp Lejeune, NC 28547, USA. [ABSTRACT FROM AUTHOR]

Aplite dikes intruding the Proterozoic 1.42(± 3) Ga Longs Peak-St. Vrain Silver Plume-type peraluminous granite near Jamestown, Colorado, contain F, P, and rare earth element (REE)-rich globular segregations, with 40-46% REE, 3.7-4.8 wt% P2O5, and 5-8 wt% F. A combination of textural features and geochemical data suggest that the aplite and REE-rich globular segregations co-existed as two co-genetic liquids prior to their crystallization, and we propose that they are formed by silicate-fluoride + phosphate (+ S + CO2) melt immiscibility following ascent, cooling, and decompression of what was initially a single homogeneous magma that intruded the granite. The REE distribution coefficients between the silica-rich aplites and REE-rich segregations are in good agreement with experimentally determined distribution coefficients for immiscible silicate-fluoride + phosphate melts. Although monazite-(Ce) and uraninite U-Th-Pb microprobe ages for the segregations yield 1.420(± 25) and 1.442(± 8) Ga, respectively, thus suggesting a co-genetic relationship with their host granite, εNd1.42Ga values for the granites and related granitic pegmatites range from − 3.3 to − 4.7 (average − 3.9), and differ from the values for both the aplites and REE-rich segregations, which range from − 1.0 to − 2.2 (average − 1.6). Furthermore, the granites and pegmatites have (La/Yb)N <50 with significant negative Eu anomalies, which contrast with higher (La/Yb)N >100 and absence of an Eu anomaly in both the aplites and segregations. These data are consistent with the aplite dikes and the REE-rich segregations they contain being co-genetic, but derived from a source different from that of the granite. The higher εNd1.42Ga values for the aplites and REE-rich segregations suggest that the magma from which they separated had a more mafic and deeper, dryer and hotter source in the lower crust or upper mantle compared to the quartzo-feldspathic upper crustal source proposed for the Longs Peak-St. Vrain granite. [ABSTRACT FROM AUTHOR]