A Proposal for a Common Minimal Topic Set in Introductory Biology Courses for Majors

A common complaint among instructors of introductory biology courses is the course covers too much material. Without a national consensus specifying which topics are essential, instructors are leery of excluding material. A survey was administered to Two-Year College and Four-Year College and University section members of the National Association of Biology Teachers (NABT) to identify the topics and skills college and university biology instructors believe students completing introductory biology should know and comprehend. Analysis identified a strong consensus for twenty topics and seven skills that should be included in all year-long introductory college biology course sequences for majors

Redesigning Introductory Biology: A Proposal

With the increasing complexity and expansion of the biological sciences, there has been a corresponding increase in content in the first-year introductory biology course sequence for majors. In general this has resulted in courses that introduce students to large amounts of material and leave little time for practicing investigative science or skill development. Based on our analysis of data compiled from 742 biology faculty at a variety of institutions across the United States, we verified that there is strong agreement on the content appropriate for introductory biology courses for majors. Therefore, we propose that faculty teaching these courses focus primarily on the topics identified in this study, and redesign their courses to incorporate active learning strategies that emphasize the investigative nature of biology and provide opportunities for skill development

Spectroscopy of CASSOWARY gravitationally-lensed galaxies in SDSS: characterisation of an extremely bright reionization-era analog at z=1.42z=1.42

We present new observations of sixteen bright ($r=19-21$) gravitationally lensed galaxies at $z\simeq 1-3$ selected from the CASSOWARY survey. Included in our sample is the $z=1.42$ galaxy CSWA-141, one of the brightest known reionization-era analogs at high redshift (g=20.5), with a large sSFR (31.2 Gyr$^{-1}$) and an [OIII]+H$\beta$ equivalent width (EW$_{\rm{[OIII]+H\beta}}$=730~\r{A}) that is nearly identical to the average value expected at $z\simeq 7-8$. In this paper, we investigate the rest-frame UV nebular line emission in our sample with the goal of understanding the factors that regulate strong CIII] emission. Whereas most of the sources in our sample show weak UV line emission, we find elevated CIII] in the spectrum of CSWA-141 (EW$_{\rm{CIII]}}$=4.6$\pm1.9$~\r{A}) together with detections of other prominent emission lines (OIII], Si III], Fe II$^\star$, Mg II). We compare the rest-optical line properties of high redshift galaxies with strong and weak CIII] emission, and find that systems with the strongest UV line emission tend to have young stellar populations and nebular gas that is moderately metal-poor and highly ionized, consistent with trends seen at low and high redshift. The brightness of CSWA-141 enables detailed investigation of the extreme emission line galaxies which become common at $z>6$. We find that gas traced by the CIII] doublet likely probes higher densities than that traced by [OII] and [SII]. Characterisation of the spectrally resolved Mg II emission line and several low ionization absorption lines suggests neutral gas around the young stars is likely optically thin, potentially facilitating the escape of ionizing radiation.Comment: 20 pages, 9 figures, Accepted for publication in MNRA

The Spatial, Ionization, and Kinematic Conditions of the z=1.39 Damped Ly-alpha Absorber in Q0957+561 A,B

We examined the sizes of the absorption clouds in a z=1.3911 damped Ly-alpha absorber (DLA) in the double image lensed quasar Q0957+561 A,B (separation 135 pc at the absorber redshift). Using HIRES/Keck spectra, we studied the MgII 2796,2803 doublet, FeII multiplet, and MgI 2853 transition in absorption. We defined six "clouds" in the system of sightline A and seven clouds in the system of sightline B. An examination of the N(v) profiles, using the apparent optical depth method, reveals no clear physical connection between the clouds in A and those in B. The observed column density ratios of all clouds is log[N(MgI)/N(FeII)] ~ -2 across the full velocity range in both systems and also spatially (in both sightlines). This is a remarkable uniformity not seen in Lyman limit systems. The uniformity of the cloud properties suggests that the multiple clouds are not part of a "halo". Based upon photoionization modeling, we constrain the ionization parameters in the range -6.2 < log(U) < -5.1, where the range brackets known abundance ratio and dust depletion patterns. The inferred cloud properties are densities of 2 < n_H < 20 cm^-3, and line of sight sizes of 1 < D < 25 pc. The masses of the clouds in system A are 10 < M/M_sun < 1000 and in system B are 1 < M/M_sun < 60 for spherical clouds. For planar clouds, the upper limits are 400 M_sun and 160 M_sun for A and B, respectively. We favor a model of the absorber in which the DLA region itself is a single cloud in thiscomplex, which could be a parcel of gas in a galactic ISM. A spherical cloud of ~10 pc would be limited to one of the sightlines (A) and imply a covering factor less than 0.1 for the DLA complex. We infer that the DLA cloud properties are consistent with those of lower density, cold clouds in the Galactic interstellar medium.Comment: Accepted for publication in the Astrophysical Journal; final versio

Understanding Early Elementary Children's Conceptual Knowledge of Plant Structure and Function through Drawings

We present the results of an early elementary study (K–1) that used children's drawings to examine children's understanding of plant structure and function.This study examined children's drawings to explain children's conceptual understanding of plant structure and function. The study explored whether the children's drawings accurately reflect their conceptual understanding about plants in a manner that can be interpreted by others. Drawing, survey, interview, and observational data were collected from 182 students in grades K and 1 in rural southeastern United States. Results demonstrated the children held a wide range of conceptions concerning plant structure and function. These young children held very simple ideas about plants with respect to both their structure and function. Consistent with the drawings, the interviews presented similar findings

The Health Equity Promotion Model: Reconceptualization of Lesbian, Gay, Bisexual, and Transgender (LGBT) Health Disparities

National health initiatives emphasize the importance of eliminating health disparities among historically disadvantaged populations. Yet, few studies have examined the range of health outcomes among lesbian, gay, bisexual, and transgender (LGBT) people. To stimulate more inclusive research in the area, we present the Health Equity Promotion Model—a framework oriented toward LGBT people reaching their full mental and physical health potential that considers both positive and adverse health-related circumstances. The model highlights (a) heterogeneity and intersectionality within LGBT communities; (b) the influence of structural and environmental context; and (c) both health-promoting and adverse pathways that encompass behavioral, social, psychological, and biological processes. It also expands upon earlier conceptualizations of sexual minority health by integrating a life course development perspective within the health-promotion model. By explicating the important role of agency and resilience as well as the deleterious effect of social structures on health outcomes, it supports policy and social justice to advance health and well-being in these communities. Important directions for future research as well as implications for health-promotion interventions and policies are offered

The testis and epididymis are productively infected by SIV and SHIV in juvenile macaques during the post-acute stage of infection

BACKGROUND: Little is known about the progression and pathogenesis of HIV-1 infection within the male genital tract (MGT), particularly during the early stages of infection. RESULTS: To study HIV pathogenesis in the testis and epididymis, 12 juvenile monkeys (Macacca nemestrina, 4–4.5 years old) were infected with Simian Immunodeficiency Virus mac 251 (SIV(mac251)) (n = 6) or Simian/Human Immunodeficiency Virus (SHIV(mn229)) (n = 6). Testes and epididymides were collected and examined by light microscopy and electron microscopy, at weeks 11–13 (SHIV) and 23 (SIV) following infection. Differences were found in the maturation status of the MGT of the monkeys, ranging from prepubertal (lacking post-meiotic germ cells) to post-pubertal (having mature sperm in the epididymal duct). Variable levels of viral RNA were identified in the lymph node, epididymis and testis following infection with both SHIV(mn229 )and SIV(mac251). Viral protein was detected via immunofluorescence histochemistry using specific antibodies to SIV (anti-gp41) and HIV-1 (capsid/p24) protein. SIV and SHIV infected macrophages, potentially dendritic cells and T cells in the testicular interstitial tissue were identified by co-localisation studies using antibodies to CD68, DC-SIGN, αβTCR. Infection of spermatogonia, but not more mature spermatogenic cells, was also observed. Leukocytic infiltrates were observed within the epididymal stroma of the infected animals. CONCLUSION: These data show that the testis and epididymis of juvenile macaques are a target for SIV and SHIV during the post-acute stage of infection and represent a potential model for studying HIV-1 pathogenesis and its effect on spermatogenesis and the MGT in general

TECHNIQUES FOR REARING AND RELEASING NONMIGRATORY CRANES: LESSONS FROM THE MISSISSIPPI SANDHILL CRANE PROGRAM

Captive-reared Mississippi sandhill cranes (Grus canadensis pulla) reared at the Patuxent Wildlife Research Center (patuxent) have been released at the Mississippi Sandhill Crane National Wildlife Refuge (MSCNWR) since 1981. Of 131 birds released through December 1990, 103 were reared by foster parents. The remaining 28 were experimentally hand-reared in 1989 and 1990. After refining release procedures, parent-reared birds have integrated into the wild flock, many have survived, and some have bred. Releases of hand-reared cranes elsewhere in the 1970\u27s were largely unsuccessful. at least in part due to the lack of a lengthy acclimation period. A new hand-rearing protocol holds promise in producing release-worthy birds. The technique employs some features first used in the 1960\u27s (e.g., a costume for the human caretaker and model crane heads used to train chicks to feed). In the mid-1980\u27s, the following features were added: (1) the costumed caretaker was given a visor and feathers, (2) a taxidermic crane head or a hand puppet was held or suspended from the ceiling for use in stimulating chicks to feed, (3) a taxidermic mount of a brooding crane supplied warmth, (4) a full-sized live crane was maintained in an adjacent pen and in visual contact with neonatal young to provide an imprinting model, and (5) a small group of adult (or subadult) cranes was penned adjacent to the outdoor chick pens to provide socialization models. Recent releases of Mississippi sandhill cranes hand-reared according to this protocol and released in Mississippi have had high first-year survival rates. The now-operational technique holds promise for producing large numbers of release-worthy birds

TECHNIQUES FOR REARING AND RELEASING NONMIGRATORY CRANES: LESSONS FROM THE MISSISSIPPI SANDHILL CRANE PROGRAM

Captive-reared Mississippi sandhill cranes (Grus canadensis pulla) reared at the Patuxent Wildlife Research Center (patuxent) have been released at the Mississippi Sandhill Crane National Wildlife Refuge (MSCNWR) since 1981. Of 131 birds released through December 1990, 103 were reared by foster parents. The remaining 28 were experimentally hand-reared in 1989 and 1990. After refining release procedures, parent-reared birds have integrated into the wild flock, many have survived, and some have bred. Releases of hand-reared cranes elsewhere in the 1970\u27s were largely unsuccessful. at least in part due to the lack of a lengthy acclimation period. A new hand-rearing protocol holds promise in producing release-worthy birds. The technique employs some features first used in the 1960\u27s (e.g., a costume for the human caretaker and model crane heads used to train chicks to feed). In the mid-1980\u27s, the following features were added: (1) the costumed caretaker was given a visor and feathers, (2) a taxidermic crane head or a hand puppet was held or suspended from the ceiling for use in stimulating chicks to feed, (3) a taxidermic mount of a brooding crane supplied warmth, (4) a full-sized live crane was maintained in an adjacent pen and in visual contact with neonatal young to provide an imprinting model, and (5) a small group of adult (or subadult) cranes was penned adjacent to the outdoor chick pens to provide socialization models. Recent releases of Mississippi sandhill cranes hand-reared according to this protocol and released in Mississippi have had high first-year survival rates. The now-operational technique holds promise for producing large numbers of release-worthy birds