Spatial Relation of Stem Hydroids to Branch Hydroids in Four Pleurocarpous Mosses

The anatomy of branch and main stem connections, with respect to the spatial relation of central strands, was studied in four species of pleurocarpous mosses: Climacium americanum, Climacium dendroides, Rhytidiadelphus triquetrus, and Rhytidium rugosum. In each of these species the central strand consisted entirely of hydroids. Fresh specimens obtained in Iowa and Wisconsin were fixed in CRAF III. To soften tough cell walls, samples were soaked in concentrated (50% aqueous) hydrofluoric acid for one week prior to dehydration in ethyl alcohol. Paraffin (61°c mp) was used as the embedding medium. In the several branch connections studied for each species there was no direct connection between stem and branch central strands

University Evolution Education: The Effect of Evolution Instruction on Biology Majors’ Content Knowledge, Attitude Toward Evolution, and Theistic Position

Issues regarding understanding of evolution and resistance to evolution education in the United States are of key importance to biology educators at all levels. While research has measured student views toward evolution at single points in time, few studies have been published investigating whether views of college seniors are any different than first-year students in the same degree program. Additionally, students choosing to major in biological sciences have largely been overlooked, as if their acceptance of evolution is assumed. This study investigated the understanding of evolution and attitude toward evolution held by students majoring in biological science during their first and fourth years in a public research university. Participants included students in a first-year introductory biology course intended for biological science majors and graduating seniors earning degrees in either biology or genetics. The portion of the survey reported here consisted of quantitative measures of students’ understanding of core concepts of evolution and their attitude toward evolution. The results indicate that students’ understanding of particular evolutionary concepts is significantly higher among seniors, but their attitude toward evolution is only slightly improved compared to their first-year student peers. When comparing first-year students and seniors, students’ theistic position was not significantly different

Spitzer Observations of the z=2.73 Lensed Lyman Break Galaxy, MS1512-cB58

We present Spitzer infrared (IR) photometry and spectroscopy of the lensed Lyman break galaxy (LBG), MS1512-cB58 at z=2.73. The large (factor ~30) magnification allows for the most detailed infrared study of an L*_UV(z=3) LBG to date. Broadband photometry with IRAC (3-10 micron), IRS (16 micron), and MIPS (24, 70 & 160 micron) was obtained as well as IRS spectroscopy spanning 5.5-35 microns. A fit of stellar population models to the optical/near-IR/IRAC photometry gives a young age (~9 Myr), forming stars at ~98 M_sun/yr, with a total stellar mass of ~10^9 M_sun formed thus far. The existence of an old stellar population with twice the stellar mass can not be ruled out. IR spectral energy distribution fits to the 24 and 70 micron photometry, as well as previously obtained submm/mm, data give an intrinsic IR luminosity L_IR = 1-2 x10^11 L_sun and a star formation rate, SFR ~20-40 M_sun/yr. The UV derived star formation rate (SFR) is ~3-5 times higher than the SFR determined using L_IR or L_Halpha because the red UV spectral slope is significantly over predicting the level of dust extinction. This suggests that the assumed Calzetti starburst obscuration law may not be valid for young LBGs. We detect strong line emission from Polycyclic Aromatic Hydrocarbons (PAHs) at 6.2, 7.7, and 8.6 microns. The line ratios are consistent with ratios observed in both local and high redshift starbursts. Both the PAH and rest-frame 8 micron luminosities predict the total L_IR based on previously measured relations in starbursts. Finally, we do not detect the 3.3 micron PAH feature. This is marginally inconsistent with some PAH emission models, but still consistent with PAH ratios measured in many local star-forming galaxies.Comment: Accepted for publication in ApJ. aastex format, 18 pages, 7 figure

University Faculty and Their Knowledge & Acceptance of Biological Evolution

Misconceptions about biological evolution specifically and the nature of science in general are pervasive in our society and culture. The view that biological evolution explains life’s origin(s) and that hypotheses become theories, which then become laws are just two examples of commonly held misconceptions. These misconceptions are reinforced in the media, in people’s personal lives, and in some unfortunate cases in the science classroom. Misconceptions regarding the nature of science (NOS) have been shown to be related to understanding and acceptance of biological evolution. Previous work has looked at several factors that are related to an individual’s understanding of biological evolution, acceptance of biological evolution, and his/her understanding of the NOS. The study presented here investigated understanding and acceptance of biological evolution among a highly educated population: university faculty. To investigate these variables we surveyed 309 faculty at a major public Midwestern university. The questions at the core of our investigation covered differences across and between faculty disciplines, what influence theistic position or other demographic responses had, and what model best described the relationships detected. Our results show that knowledge of biological evolution and acceptance of biological evolution are positively correlated for university faculty. Higher knowledge of biological evolution positively correlates with higher acceptance of biological evolution across the entire population of university faculty. This positive correlation is also present if the population is broken down into distinct theistic views (creationist and non-creationist viewpoints). Greater knowledge of biological evolution also positively correlates with greater acceptance of biological evolution across different levels of science education. We also found that of the factors we examined, theistic view has the strongest relationship with knowledge and acceptance of biological evolution. These results add support to the idea that a person’s theistic view is a driving force behind his or her resistance to understanding and accepting biological evolution. We also conclude that our results support the idea that effective science instruction can have a positive effect on both understanding and acceptance of biological evolution and that understanding and acceptance are closely tied variables

Spitzer infrared spectrometer 16μm observations of the GOODS fields

We present Spitzer 16μm imaging of the Great Observatories Origins Deep Survey (GOODS) fields. We survey 150 arcmin^2 in each of the two GOODS fields (North and South), to an average 3σ depth of 40 and 65 μJy, respectively. We detect ~1300 sources in both fields combined. We validate the photometry using the 3–24μm spectral energy distribution of stars in the fields compared to Spitzer spectroscopic templates. Comparison with ISOCAM and AKARI observations in the same fields shows reasonable agreement, though the uncertainties are large. We provide a catalog of photometry, with sources cross-correlated with available Spitzer, Chandra, and Hubble Space Telescope data. Galaxy number counts show good agreement with previous results from ISOCAM and AKARI with improved uncertainties. We examine the 16–24μm flux ratio and find that for most sources it lies within the expected locus for starbursts and infrared luminous galaxies. A color cut of S_(16)/S_(24) > 1.4 selects mostly sources which lie at 1.1 < z < 1.6, where the 24μm passband contains both the redshifted 9.7 μm silicate absorption and the minimum between polycyclic aromatic hydrocarbon emission peaks. We measure the integrated galaxy light of 16μm sources and find a lower limit on the galaxy contribution to the extragalactic background light at this wavelength to be 2.2 ± 0.2 nW m^(−2) sr^(−1)

zrp2: a novel maize gene whose mRNA accumulates in the root cortex and mature stems

A near full-length cDNA clone (pZRP2) was isolated from a cDNA library constructed from maize root mRNAs. The predicted polypeptide has a calculated molecular mass of 66 975 Da, is largely hydrophilic, and contains 26 repeats of a motif the consensus sequence of which is RKATTSYG[S][D/E][D/E][D/E][D/E][P]. The function of the putative protein remains to be elucidated. The ZRP2 mRNA accumulates to the highest levels in young roots, and is also present in mature roots and stems of maize. Further analysis of young roots indicates that the lowest level of ZRP2 mRNA is near the root tip, with relatively high levels throughout the remainder of the root. In situ hybridization reveals that ZRP2 mRNA accumulates predominantely in the cortical parenchyma cells of the root. In vitro nuclear run-on transcription experiments indicate a dramatically higher level of zrp2 gene transcription in 3-day old roots than in 5-day old leaves. A zrp2 genomic clone, which includes the transcribed region and 4.7 kb of upstream sequence, was isolated and characterized.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43444/1/11103_2004_Article_142986.pd