Two Species of Alethopteris From Iowa Coal Balls

Petrified specimens of Alethopteris sullivanti (Lesquereux) Schimper and Alethopteris lesquereuxi Wagner, species of Pennsylvania seed fern leaves, were found in coal balls from the Lovilia locality in south central Iowa. The morphology and anatomy of these leaves are described and are compared with findings of previous workers (Leisman, 1960; Baxter and Willhite, 1969). It is generally accepted that Alethopteris is a foliage type of the Pennsylvania pteridosperm, Medullosa (Scott, 1899; Steidtman, 1944). Evidence cited to support this includes the attachment of seeds to Alethopteris foliage (Halle, 1927), the common association of the genus with Myeloxylon, Dolerotheca, Pachytesta, and other organ genera of medullosan affinity, and the anatomical similarities of the leaves with Myeloxylon petioles (Leisman, 1960; Ramanujam et al., 1974). The genus, Alethopteris, was established by Sternberg in 1825 to describe a fern-like compression foliage. Most subsequent studies of the genus have been confined to compression material. A summary of this work is found in Wagner\u27s comprehensive monograph (1968). Alethopteris sullivanti (Lesquereux) Schimper and Alethopteris lesquereuxi Wagner are the only Pennsylvanian species of which the details of internal anatomy are known from petrified coal ball material (Leisman, 1960; Baxter and Willhite, 1969). Wagner (1968, pp. 16-17) believes that the classification of Carboniferous fern-like foliage into natural genera must be based on several different features. These are 1) the general morphology of the frond and its pinnae, 2) epidermal characteristics as preserved in cuticles, 3) fructifications, 4) pinnule morphology and ontogenetic pattern. Wagner feels that ultimately studies of cuticles will be particularly useful in establishing natural genera. This paper describes the morphology and anatomy of Alethopteris sullivanti and A. lesquereuxi leaves found in Iowa coal balls. It also includes a study of the cuticles of these species

Evaluating Honors Programs: An Outcomes Approach

The evaluation of academic programs has always been a complex and sensitive issue. Evaluations are undertaken to determine which programs will survive in an era of straitened economic circumstances, to gain or maintain accreditation, or to tell us how our programs can be improved. They may apply some normative standard of quality, 0r address an academic program\u27s unique situation and mission. They may include the following: review of budget, evaluation of staff, description of the program\u27s operation, demonstration of faculty and student satisfaction, or measures of what students have learned. They may use standardized or locally developed tests of achievement; tests of ethical and cognitive development; analysis of demographic data; transcript analysis; course evaluations; exit examinations; or faculty, student, and alumni surveys. In the seven years since NCHC published Handbook for the Evaluation of an Honors Program, demonstrating the effectiveness of academic programs has become a widespread obligation, and educators have approached this task with increased sophistication. The most commonly cited causes of this trend are recent indictments of higher education in widely publicized national reports, and the determination of governments and governing boards (and provosts and deans) to ensure that support for education is money well spent (Warren 3). Whatever the cause, evaluation has become a central academic responsibility

Low-Level Prenatal and Postnatal Blood Lead Exposure and Adrenocortical Responses to Acute Stress in Children

BACKGROUND: A few recent studies have demonstrated heightened hypothalamic–pituitary–adrenal (HPA) axis reactivity to acute stress in animals exposed to heavy metal contaminants, particularly lead. However, Pb-induced dysregulation of the HPA axis has not yet been studied in humans. OBJECTIVE: In this study, we examined children’s cortisol response to acute stress (the glucocorticoid product of HPA activation) in relation to low-level prenatal and postnatal Pb exposure. METHODS: Children’s prenatal blood Pb levels were determined from cord blood specimens, and postnatal lead levels were abstracted from pediatrician and state records. Children’s adrenocortical responses to an acute stressor were measured using assays of salivary cortisol before and after administration of a standard cold pressor task. RESULTS: Pb exposure was not associated with initial salivary cortisol levels. After an acute stressor, however, increasing prenatal and postnatal blood Pb levels were independently associated with significantly heightened salivary cortisol responses. CONCLUSIONS: Our results suggest that relatively low prenatal and postnatal blood lead levels— notably those below the 10 µg/dL blood lead level identified by the Centers for Disease Control and Prevention for public health purposes—can alter children’s adrenocortical responses to acute stress. The behavioral and health consequences of this Pb-induced HPA dysregulation in children have yet to be determined

Evaluating Honors Programs: An Outcomes Approach

The evaluation of academic programs has always been a complex and sensitive issue. Evaluations are undertaken to determine which programs will survive in an era of straitened economic circumstances, to gain or maintain accreditation, or to tell us how our programs can be improved. They may apply some normative standard of quality, 0r address an academic program\u27s unique situation and mission. They may include the following: review of budget, evaluation of staff, description of the program\u27s operation, demonstration of faculty and student satisfaction, or measures of what students have learned. They may use standardized or locally developed tests of achievement; tests of ethical and cognitive development; analysis of demographic data; transcript analysis; course evaluations; exit examinations; or faculty, student, and alumni surveys. In the seven years since NCHC published Handbook for the Evaluation of an Honors Program, demonstrating the effectiveness of academic programs has become a widespread obligation, and educators have approached this task with increased sophistication. The most commonly cited causes of this trend are recent indictments of higher education in widely publicized national reports, and the determination of governments and governing boards (and provosts and deans) to ensure that support for education is money well spent (Warren 3). Whatever the cause, evaluation has become a central academic responsibility

Laminar flow over transverse rectangular cavities

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. An experimental investigation was conducted on the laminar flow of water over transverse rectangular cavities. Most of the cavities were square ranging in size from 1/8 in. to 1 in. The flow over the cavities was observed for an [epsilon]* range of from 16 to 400. The quantity [epsilon]* may be regarded as a Reynolds number for the cavity. It is defined as [...] where [epsilon] is the cavity depth, [...] is the shear velocity, and [...] is the kinematic viscosity of the fluid. The desired flow approaching the cavities was obtained one foot from the leading edge of a flat plate suspended in an open surface water tunnel at free stream velocities from 0.125 to 0.75 ft/sec. Visual studies, instantaneous velocity measurements, and velocity profile determinations confirmed that the flow was laminar. The velocity measurements were obtained by means of a hot-film anemometer. The primary goal of the investigation was to determine whether the strong random mass-exchange activity observed in identical cavities in turbulent flow in the same [epsilon]* range was due to an inherent instability of the cavity flow or due to the excitation from turbulent fluctuations at the cavity opening. As the present experiments showed no such strong mass exchange, it was concluded that the latter mechanism was indeed the essential factor. In conjunction with these studies the flow patterns in the cavities were examined by visualization techniques and cavity velocity measurements were made. The cavity vortex velocities were found to be less than 8 percent of the free stream velocity in the range of [epsilon]* examined. In addition a laminar oscillation was observed in the shear layer at the cavity opening and its frequencies are reported. Photographic material on pp. 93-133 are essential and will not clearly reproduce on Xerox copies. Photographic copies should be ordered