Gifted student achievement and motivation levels related to participation in gifted programming

This study evaluated the gifted program of an urban school district in the Midwestern United States. Fifteen identified gifted students ( 4 male, 11 female; 11 European-American, 4 African-American; 7 ninth grade, 4 tenth grade, and 4 eleventh grade students) participated in the study by replying to a survey. High school gifted student attitudes toward achievement and motivation were examined and open-ended prompts supplied information on program strengths and weaknesses. Results indicate that participation in the program has led to the development of critical thinking skills, increased students \u27 desires to strive for excellence, and allowed students to examine different perspectives. Students suggested the program should add more independent work, more challenging and in-depth project work to courses, incorporate more advanced work into regular coursework, and continue to provide opportunities for gifted students to interact with their intellectual peers

Observations of juvenile sandbar sharks Carcharhinus plumbeus (Nardo, 1827) around the Bojana River delta (Southern Adriatic Sea)

The sandbar shark (Carcharhinus plumbeus) is considered rare in the Adriatic Sea and the majority of records originate from the northern Adriatic, where a nursery area for this species close to the Po delta system has been repeatedly proposed. This study provides 5 new records and analyses the previously published records of sandbar sharks recorded around the delta of the River Bojana (in Montenegro, in the south-eastern Adriatic). The River Bojana located on the border between Montenegro and Albania, is the second largest river flowing into the Adriatic Sea, where it forms a highly productive ecosystem already known as a local hotspot for smooth-hound sharks (Mustelus spp.). New records of sandbar sharks have emerged as a result of citizen science (a social media survey) and direct reports from fishermen. The total length of C. plumbeus juveniles ranged from approximately 800 mm to 1100 mm, and most (n=5) were caught by set gillnets. The data presented here show that juveniles are consistently present around the estuary and indicate the importance of this fragile estuarine ecosystem for sandbar sharks. Additionally, this study also provides morphometric data collected from a single individual

Analyzing the Creative Problem-Solving Process: Inventing a Product from a Given Recyclable Item

Detailed documentations of creative invention are scarce in the professional literature, but could be useful to those engaging in or studying the problem solving process. This investigation describes the creative process of graduate students (7 female, 4 male) in a problem-solving theory and practice course grappling with the task of creating products from four identical recyclable items that were circular, star-impressed bottoms of plastic juice bottles. Several popular models of the problem-solving process are compared to the participants’ steps in this invention problem. Participants first provided emotional reactions to the given ill-defined problem of making a product from the specified items. They used several techniques to generate ideas and to restrict or define the problem, choosing an optimal product that fits their require-ments. An analysis of participants’ reflections concerning their creative process showed that although participants first found the problem challenging and could not conceptualize effective products, the idea-generating activities assisted them in making a wide variety of useful products. Participants’ knowledge and skill areas were highlighted by their choices of products. After completing and presenting a first product, participants engaged in additional activities to generate ideas for a second product. The second product was either an improvement of the first product, a new but related product, or a product inspired by the work of others in the class. Products of this loosely defined problem included: maracas, dish, spin top, candy suckers, closet organizers, party decorations, yoyo, ladybug, wall décor, flowers, catch game, party hat, candle holders, moth life cycle, catapult game, toy clock, goblets, castanets, accessory organizer, and spice shaker

Tooth mineralization and histology patterns in extinct and extant snaggletooth sharks, Hemipristis (Carcharhiniformes, Hemigaleidae)—Evolutionary significance or ecological adaptation?

Shark jaws exhibit teeth that are arranged into distinct series and files and display great diversities in shapes and structures, which not only is related to their function (grasping, cutting, crushing) during feeding, but also bear a strong phylogenetic signal. So far, most research on the relationship between shark teeth and feeding ecology and systematics focused on the external tooth morphology only. Although the tooth histology of sharks has been examined since the early 19th century, its functional and systematic implications are still ambiguous. Shark teeth normally consist of either a porous, cellular dentine, osteodentine (in lamniform sharks and some batoids) or a dense layer of orthodentine (known from different sharks). Sharks of the order Carcharhiniformes, comprising ca. 60% of all extant shark species, are known to have orthodont teeth, with a single exception—the snaggletooth shark, Hemipristis elongata. High resolution micro-CT images of jaws and teeth from selected carcharhiniform sharks (including extant and fossil snaggletooth sharks) and tooth sections of teeth of Hemipristis, other carcharhiniform and lamniform sharks, have revealed that (1) Hemipristis is indeed the only carcharhiniform shark filling its pulp cavity with osteodentine in addition to orthodentine, (2) the tooth histology of Hemipristis elongata differs from the osteodont histotype, which evolved in lamniform sharks and conversely represents a modified orthodonty, and (3) this modified orthodonty was already present in extinct Hemipristis species but the mineralization sequence has changed over time. Our results clearly show the presence of a third tooth histotype—the pseudoosteodont histotype, which is present in Hemipristis. The unique tooth histology of lamniform sharks might provide a phylogenetic signal for this group, but more research is necessary to understand the phylogenetic importance of tooth histology in sharks in general

Micro computed tomography imaging reveals the development of a unique tooth mineralization pattern in mackerel sharks (Chondrichthyes; Lamniformes) in deep time

The cartilaginous fishes (Chondrichthyes) have a rich fossil record which consists mostly of isolated teeth and, therefore, phylogenetic relationships of extinct taxa are mainly resolved based on dental characters. One character, the tooth histology, has been examined since the 19th century, but its implications on the phylogeny of Chondrichthyes is still in debate. We used high resolution micro-CT images and tooth sections of 11 recent and seven extinct lamniform sharks to examine the tooth mineralization processes in this group. Our data showed similarities between lamniform sharks and other taxa (a dentinal core of osteodentine instead of a hollow pulp cavity), but also one feature that has not been known from any other elasmobranch fish: the absence of orthodentine. Our results suggest that this character resembles a synapomorphic condition for lamniform sharks, with the basking shark, Cetorhinus maximus, representing the only exception and reverted to the plesiomorphic tooth histotype. Additionally, †Palaeocarcharias stromeri, whose affiliation still is debated, shares the same tooth histology only known from lamniform sharks. This suggests that †Palaeocarcharias stromeri is member of the order Lamniformes, contradicting recent interpretations and thus, dating the origin of this group back at least into the Middle Jurassic

White shark comparison reveals a slender body for the extinct megatooth shark, Otodus megalodon (Lamniformes: Otodontidae)

The extinct megatooth shark, †Otodus megalodon, which likely reached at least 15 m in total length, is an iconic extinct shark represented primarily by its gigantic teeth in the Neogene fossil record. As one of the largest marine carnivores to ever exist, understanding the biology, evolution, and extinction of †O. megalodon is important because it had a significant impact on the ecology and evolution of marine ecosystems that shaped the present-day oceans. Some attempts inferring the body form of †O. megalodon have been carried out, but they are all speculative due to the lack of any complete skeleton. Here we highlight the fact that the previous total body length estimated from vertebral diameters of the extant white shark for an †O. megalodon individual represented by an incomplete vertebral column is much shorter than the sum of anteroposterior lengths of those fossil vertebrae. This factual evidence indicates that †O. megalodon had an elongated body relative to the body of the modern white shark (Carcharodon carcharias). Although its exact body form remains unknown, this proposition represents the most parsimonious empirical evidence, which is a significant step towards deciphering the much-debated body form of †O. megalodon

Articulated remains of the extinct shark Ptychodus (Elasmobranchii, Ptychodontidae) from the Upper Cretaceous of Spain provide insights into gigantism, growth rate and life history of ptychodontid sharks.

Due to their cartilaginous endoskeleton and the continuous tooth replacement, the chondrichthyan fossil record predominantly consists of isolated teeth, which offer diagnostic features for taxonomic identifications, but only provide very limited information of an organism's life history. In contrast, the calcified vertebral centra of elasmobranchs (sharks, skates and rays) yield important information about ecological and biological traits that can be utilized for constructing age-structured population dynamic models of extant species and palaeoecological reconstructions of such aspects in extinct groups. Here, we describe two large shark vertebrae from the Santonian (Upper Cretaceous) of Spain, which show a unique combination of characters (asterospondylic calcification pattern, with concentric lamellae and numerous parallel bands that are oriented perpendicular) that is only known from ptychodontid sharks, a distinct, extinct group of giant durophagous sharks of the Cretaceous era. Based on linear regression models for large extant sharks a total length between 430 and 707cm was estimated for the examined specimen. Our results indicate that ptychodontid sharks were large viviparous animals, with slow growth rates, matured very late and, therefore, show typical traits for K-selected species. These traits combined with a highly specialized feeding ecology might have played a crucial role for the success but also, eventually, extinction of this group

Analyzing the Creative Problem-Solving Process: Inventing a Product from a Given Recyclable Item

Detailed documentations of creative invention are scarce in the professional literature, but could be useful to those engaging in or studying the problem solving process. This investigation describes the creative process of graduate students (7 female, 4 male) in a problem-solving theory and practice course grappling with the task of creating products from four identical recyclable items that were circular, star-impressed bottoms of plastic juice bottles. Several popular models of the problem-solving process are compared to the participants’ steps in this invention problem. Participants first provided emotional reactions to the given ill-defined problem of making a product from the specified items. They used several techniques to generate ideas and to restrict or define the problem, choosing an optimal product that fits their require-ments. An analysis of participants’ reflections concerning their creative process showed that although participants first found the problem challenging and could not conceptualize effective products, the idea-generating activities assisted them in making a wide variety of useful products. Participants’ knowledge and skill areas were highlighted by their choices of products. After completing and presenting a first product, participants engaged in additional activities to generate ideas for a second product. The second product was either an improvement of the first product, a new but related product, or a product inspired by the work of others in the class. Products of this loosely defined problem included: maracas, dish, spin top, candy suckers, closet organizers, party decorations, yoyo, ladybug, wall décor, flowers, catch game, party hat, candle holders, moth life cycle, catapult game, toy clock, goblets, castanets, accessory organizer, and spice shaker