18,325 research outputs found
An orthonormalization procedure for multivariable function approximation
Where a function of several variables is given numerically in tabular form, an orthonormalization technique allows an approximation of the numerical data to be determined in a convenient functional form. In this technique, the speed and accuracy of coefficient computation are much improved
Ethical Development and Diversity Training for Educational Leaders
In the 21st century schools must meet the challenges of current and anticipated increases in racial and ethnic student populations. In turn, school principals must be prepared to lead diverse student populations to high levels of achievement. To facilitate adequate leadership preparation, therefore, the diversity training of educational leaders in given settings must be reworked so that the achievement gap between non-white and white students can be closed. Furthermore, restructuring of principal training is best accomplished through consensus within the profession, based on the tenets of the democratic values of respect, acceptance, and appreciation of diversity.
The purpose of this paper is to add to the body of knowledge in educational leadership degree and certification programs in regard to diversity standards and social justice relevance. This paper provides an overview of a social justice agenda that includes five key elements. The first is a discussion of the term diversity and American demography. The second element is a summary of the sociopolitical context of social justice. The third element is an examination of multicultural education. The fourth element is an overview of educational administration programs. The last element is a review of the moral and ethical leadership standards for educational administrators
Definition of smolder experiments for Spacelab
The feasibility of conducting experiments in space on smoldering combustion was studied to conceptually design specific smoldering experiments to be conducted in the Shuttle/Spacelab System. Design information for identified experiment critical components is provided. The analytical and experimental basis for conducting research on smoldering phenomena in space was established. Physical descriptions of the various competing processes pertaining to smoldering combustion were identified. The need for space research was defined based on limitations of existing knowledge and limitations of ground-based reduced-gravity experimental facilities
Ultradian, circadian and seasonal rhythms in cortisol secretion and adrenal responsiveness to ACTH and yarding in unrestrained red deer (Cervus elaphus) stags
Seasonal changes in the activity and responsiveness of the adrenal gland in red deer (Cervus elaphus) stags were quantified by measuring 24 h endogenous cortisol secretory profiles and plasma cortisol responses to either administration of exogenous ACTH or a standardised stressor during November (period of velvet growth), February (pre-rut), April (mid-rut) and July (post-rut) (southern hemisphere) using a remote blood sampling device (DracPac). Ultradian rhythms in the concentration of plasma cortisol were observed resulting from the episodic secretion of cortisol from the adrenal cortex at a mean rate of 0.8 pulses/h. Circadian rhythms in plasma cortisol concentrations were also found in 11 out of the 20 complete 24 h profiles (mean amplitude, 3.8+/-1.4 ng/ml). Seasonal rhythms in mean 24 h plasma cortisol concentrations and cortisol pulse parameters were also observed. Mean 24 h plasma cortisol concentrations were higher in November (12.5+/-1.0 ng/ml) than in February (6.3+/-1.0 ng/ml), April (4.0+/-1.0 ng/ml) or July (4.2+/-1. 0 ng/ml). Cortisol pulse height, nadir and amplitude were all significantly higher in November than at other times of the year (P<0.01). Peak cortisol concentrations following infusion of ACTH(1-24) (0.04 IU kg(-1)) were higher (P<0.05) in November (55.8+/-2.7 ng/ml) and lower (P<0.001) in April (33.7+/-1.8 ng/ml) than those in February and July (48.7+/-2.0 ng/ml and 45.4+/-2.0 ng/ml respectively). The area under the cortisol response curve was significantly smaller (P<0.05) in April (266.6+/-15.3 ng/ml/190 min) than at other times of the year (February, 366.1+/-15.3 ng/ml/190 min; July, 340.7+/-15.3 ng/ml/190 min and November, 387.8+/-21.2 ng/ml/190 min). These data demonstrate that the adrenal gland of the red deer stag exhibits ultradian, circadian and seasonal rhythms in activity, and that its responsiveness to ACTH varies with season. November, a period of reproductive quiescence in the southern hemisphere, with new antler growth and rapid weight gain, is associated with higher mean plasma cortisol concentrations and a greater responsiveness to exogenous ACTH. In contrast, the breeding season is associated with lower adrenal activity and responsiveness
PATENT PROTECTION AND PROJECT MANAGEMENT IN THE DEVELOPMENT OF NEW CROP VARIETIES: CASE STUDY OF THE HIGH PECTIN TOMATO
Intellectual property is only one element of successful R&D. Our case study tracks a GM crop variety from R&D to processing and retailing. One finding that emerged was the importance of factors besides patent protection for developing a new technology, such as effective partnering and supply chain management.Research and Development/Tech Change/Emerging Technologies,
The applicability and effectiveness of cluster analysis
An insight into the characteristics which determine the performance of a clustering algorithm is presented. In order for the techniques which are examined to accurately cluster data, two conditions must be simultaneously satisfied. First the data must have a particular structure, and second the parameters chosen for the clustering algorithm must be correct. By examining the structure of the data from the Cl flight line, it is clear that no single set of parameters can be used to accurately cluster all the different crops. The effectiveness of either a noniterative or iterative clustering algorithm to accurately cluster data representative of the Cl flight line is questionable. Thus extensive a prior knowledge is required in order to use cluster analysis in its present form for applications like assisting in the definition of field boundaries and evaluating the homogeneity of a field. New or modified techniques are necessary for clustering to be a reliable tool
Eragrostis (Poaceae): Monophyly and Infrageneric Classification
Eragrostis is a large genus in subfamily Chloridoideae of Poaceae. Recent phylogenetic analyses have suggested that the genus may not be monophyletic, that some of its segregate genera may be better placed within Eragrostis, and that current infrageneric classifications may not represent monophyletic groups. We have used molecular sequence data from the plastid locus rps16 and the nuclear gene waxy from a broad sample of Eragrostis species and representatives of six of the seven segregate genera to address these issues. We found that Eragrostis is monophyletic with the inclusion of several of the segregates, including Acamptoclados, Diandrochloa, and Neeragrostis. The placement of Cladoraphis and Stiburus is uncertain. Thellungia does not belong in Eragrostis and is actually more closely related to Sporobolus. These data also suggest that existing infrageneric classifications are inadequate and do not correspond to monophyletic groups within Eragrostis
Blue light regenerates functional visual pigments in mammals through a retinyl-phospholipid intermediate.
The light absorbing chromophore in opsin visual pigments is the protonated Schiff base of 11-cis-retinaldehyde (11cRAL). Absorption of a photon isomerizes 11cRAL to all-trans-retinaldehyde (atRAL), briefly activating the pigment before it dissociates. Light sensitivity is restored when apo-opsin combines with another 11cRAL to form a new visual pigment. Conversion of atRAL to 11cRAL is carried out by enzyme pathways in neighboring cells. Here we show that blue (450-nm) light converts atRAL specifically to 11cRAL through a retinyl-phospholipid intermediate in photoreceptor membranes. The quantum efficiency of this photoconversion is similar to rhodopsin. Photoreceptor membranes synthesize 11cRAL chromophore faster under blue light than in darkness. Live mice regenerate rhodopsin more rapidly in blue light. Finally, whole retinas and isolated cone cells show increased photosensitivity following exposure to blue light. These results indicate that light contributes to visual-pigment renewal in mammalian rods and cones through a non-enzymatic process involving retinyl-phospholipids.It is currently thought that visual pigments in vertebrate photoreceptors are regenerated exclusively through enzymatic cycles. Here the authors show that mammalian photoreceptors also regenerate opsin pigments in light through photoisomerization of N-ret-PE (N-retinylidene-phosphatidylethanolamine
Induced encystment improves resistance to preservation and storage of Acanthamoeba castellanii
Several conditions that allow the preservation, storage and rapid, efficient recovery of viable Acanthamoeba castellanii organisms were investigated. The viability of trophozoites (as determined by time to confluence) significantly declined over a period of 12 months when stored at −70°C using dimethyl sulfoxide (DMSO; 5 or 10%) as cryopreservant. As A. castellanii are naturally capable of encystment, studies were undertaken to determine whether induced encystment might improve the viability of organisms under a number of storage conditions. A. castellanii cysts stored in the presence of Mg2+ at 4°C remained viable over the study period, although time to confluence was increased from approximately 8 days to approximately 24 days over the 12-month period. Storage of cysts at −70°C with DMSO (5 or 10%) or 40% glycerol, but not 80% glycerol as cryopreservants increased their viability over the 12-month study period compared with those stored at room temperature. Continued presence of Mg2+ in medium during storage had no adverse effects and generally improved recovery of viable organisms. The present study demonstrates that A. castellanii can be stored as a non-multiplicative form inexpensively, without a need for cryopreservation, for at least 12 months, but viability is increased by storage at −70°C
An application of the requirement vs capability analysis to estimating design reliability of solid rocket motors
Design reliability parameters for solid propellant rocket engine
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