DigitalCommons@Fayetteville State University

Nonisothermal relaxation in a nonlocal medium

Alexander Umantsev et al. — Thu, 21 Feb 2013 12:33:24 PST

A study is made of the thermodynamics of a non-local medium whose evolution is governed not only by the temperature and pressure, but also by the field of a relaxation parameter. For solid-state materials which undergo a phase transition, such a relaxation parameter is the order parameter. Heat transport equations are derived together with a thermodynamic inequality which must be satisfied during relaxation. The motion of an interphase boundary during a first-order phase transition is investigated. It is shown that, if the width of the boundary exceeds a critical value, there are steady-state conditions under which the new phase formed in an exothermal transition may be at a temperature above the equilibrium temperature.

Modeling the evolution of a dendritic structure

Alexander Umantsev — Thu, 21 Feb 2013 12:25:50 PST

The authors give the results of mathematical modeling of the evolution of a dendritic structure with the aid of the model proposed in Ref. I. They show that, as also in experiment, on the side surface of the model dendrite secondary branches form and develop into the side structure. They make a detailed investigation of its evolution in the process of growth. They show that as time passes the side structure becomes coarser. They study the changes in the dendritic structure in relation to the supercooling. With increasing supercooling the structure becomes denser, then changes to a cellular form, and finally, when the supercooling is greater than one, there is a transition to globular growth forms. A comparison is made with the experimental results.

Mathematical model of growth of dendrites in a supercooled melt

Alexander Umantsev et al. — Thu, 21 Feb 2013 12:18:19 PST

Motion of a plane front during crystallization

Alexander Umantsev — Thu, 21 Feb 2013 12:10:56 PST

Many authors have studied the growth rates of crystals with a plane front. It is known that, if the advance of the boundary is determined by deviation of its state from equilibrium, then various regimes can be realized in the system, depending on the external conditions. ^1,2 However, they have not yet been obtained as different solutions of a single problem. In our work, the integral equation representing normal growth of a crystal is solved by means of an asymptotic expansion by the method of Laplace. In the second part we construct an algorithm for obtaining numerical solutions to the problem of solidification, and compare these with the analytical results.

Mathematical modeling of pathophysiology of Type 2 Diabetes

David Earl McCarter — Mon, 17 Dec 2012 14:42:45 PST

The following research of Type-2 Diabetes is modeled using a system of non-linear deterministic differential equations. The model variables include: the quantity of glucose in the blood plasma, the quantity of glycogen in the liver/tissue, the concentration of the hormone glucagon, and the concentration of insulin in the blood plasma. The appropriate interaction constants are used to depict the physiology of Type-2 Diabetes. The non-linear equations are analyzed using the principles of the Hartman-Grobman Theory. In particular, the principles of Linearized Stability are used to compute the criteria under which hypoglycemia and hyperglycemia occur. The effect of the gluconeogenesis and glycogenolysis on the plasma glucose concentration and on the morbidity of Type-2 Diabetes is demonstrated by theorems. The results of this research will provide quantitative information on Type-2 Diabetes which will enable the design of equipment to monitor the disease. ^

Silica-based growth media: Cultivating crops without soil

Samantha Lynn Bogard — Mon, 17 Dec 2012 14:42:44 PST

Crop cultivation is an essential part of life sustainment and a soil alternative would be beneficial to crop farmers by providing a more efficient means of crop production control. A soil replacement medium composed of finned amorphous silica and nutrient broth was developed and found capable of germinating seed and maintaining growth. Experimental design involved observation over three years of plant heights, taproot lengths, and lateral root numbers to assess growth in soybeans. It was shown that the silica-based growth medium germinated seeds and accelerated growth in soybeans compared to soil. However, plant growth in the silica-based growth medium could not be maintained by the methods described herein. Therefore, further refinement of methodology will be necessary. This study demonstrates a silica-based growth media is possible and may be more efficient. Use of this alternative could reduce reliance on soil and allow for control over nutrient content in crop-growth substrates. ^

How Long Is Too Long: Does The Length Of Military Deployments Lead To Domestic Abuse?

Rebecca Lohr — Mon, 17 Dec 2012 14:42:44 PST

Research has indicated a relationship between the length of deployments and the occurrence of domestic abuse in military families. The purpose of this study was to evaluate whether or not active duty military men who were deployed for thirteen or more months were more likely to abuse their spouses. Data were collected at Fort Bragg Army Post in North Carolina. Seventy-five military wives participated in this study. Fourteen respondents reported abuse with an increase in emotional and physical abuse following their spouses' most recent deployment. Due to the small sample size of 75 participants, multivariate analyses could not be completed. However, the descriptive analysis did indicate an increase in abuse after deployments. Future research is recommended to determine the impact of military deployments. ^

The role of attachment style in female subjective sexual wellbeing

Elise Nicole Fleming — Mon, 17 Dec 2012 14:42:43 PST

Female participants in committed relationships (n = 133) were assessed to investigate the relationship between attachment styles and a composite measure of female sexuality, subjective sexual wellbeing. Subjective sexual wellbeing was measured based on three variables: sexual satisfaction, sexual esteem, and sexual assertiveness (Menard & Offman, 2009). Participants' attachment style was identified using cluster analysis (secure, n = 40; anxious, n = 59; avoidant, n = 34). A MANCOVA was conducted to assess group differences for each attachment style's relationship with subjective sexual wellbeing, while controlling for sexual functioning and relationship satisfaction. Attachment style was found to have no significant relationship with subjective sexual wellbeing beyond sexual functioning and relationship satisfaction for this sample ( V = .034, F(6, 254) = .730, p = .626). The results of this study are limited, given observed low power due to a deflated sample size in relation to the variables in this analysis. ^

Testing the efficacy of robot-to-human goal directed actions

Alissa Baker-Oglesbee — Mon, 17 Dec 2012 14:42:43 PST

Robotic technology is rapidly being integrated into human life. One aspect of robotics is as an educational tool to aide humans in learning skills. The mirror neuron system has been indicated in the process of learning motor skills from others and understanding motor goals. Study has shown that humans may have difficulty learning motor skills from non-humans, and there has been little study focused on whether humans can understand motor goals from non-humans. The current study questions whether humans can learn a motor task from a robot and also whether a human can acquire goal understanding from a robotically performed motor task. The current study also posits that the mirror neuron system be considered a strong example of embodiment. Participants viewed either a human or a robot performing motor tasks. The participants then attempted the motor task demonstrated while timed and tracked for error. Measurements were analyzed revealing significant differences in error within group but not between groups. Implications of research are beneficial in the novel combination of the mirror neuron system with embodiment theory and in gauging a robot-human interaction through a motor-teaching paradigm. ^ Keywords: robotics, mirror neuron system, goal understanding, embodiment. ^

The relationship between rap music, media literacy and perception of romantic relationship commitment among African Americans

Jennifer Elizabeth Sykes — Mon, 17 Dec 2012 14:42:42 PST

The purpose of this current study is to examine the relationships between rap music media literacy and the perception of commitment to monogamous relationships among African American college students at a historically Black college in the southeastern United States. Students were given questionnaires assessing demographic characteristics, music listening habits, media literacy and perception toward relationships. It was hypothesized that greater media literacy would be related to a higher desire for committed romantic relationships and a more positive perception towards committed relationships. The results of ordinary least squares regression analyses revealed that acceptance of the attitudes within rap music and a personal identification with these messages is associated with a more adversarial attitude toward committed relationships. Furthermore the results also revealed that female gender and rejection of the messages in rap music are more likely to be associated with a higher desire for a committed relationship and understandably an adversarial attitude toward relationships is associated with less desire to be in a committed relationship. These findings indicate that increased media literacy may be an avenue for potential intervention. ^

Racism, crime and collective efficacy: Media representation of an urban community

Leslie-Dawn Quick — Mon, 17 Dec 2012 14:42:41 PST

This study explored media representation of the Murchison Road area in Fayetteville, North Carolina, with respect to crime, public safety and collective efficacy. Research on crime and collective efficacy suggests that collective efficacy is an important element of public safety and that neighborhood image is an important element of collective efficacy. The study is an investigation of the image of the Murchison Road area constructed within The Fayetteville Observer in the period from 1988 through 2011. The study identified changes in the image of the Murchison Road area over time, explored the social and political context for media images of the area, and examined the relationship between the media image of Murchison Road and neighborhood revitalization initiatives that were proposed during the time period. ^

Development Gender and Fertility in Iran

Akbar Aghajanian — Fri, 30 Nov 2012 07:09:59 PST

The Critical Thinking Course at Fayetteville State: A Pilot Study

Akbar Aghajanian et al. — Fri, 30 Nov 2012 07:09:58 PST

Dinodang: The Melon Rex Myth

Philip J. Senter — Tue, 18 Sep 2012 12:15:17 PDT

Evidence for a sauropod−like metacarpal configuration in stegosaurian dinosaurs

Philip J. Senter — Tue, 18 Sep 2012 12:15:16 PDT

The stegosaurian forelimb is usually portrayed with the metacarpals slanted and distally spread. However, manual manipulation of stegosaurian metacarpals reveals that in that configuration they do not articulate with each other nor with the rest of the forelimb. Rather, they do articulate with each other and with the rest of the forelimb when posed vertically and arranged in a compact, semi−tubular configuration, as in sauropods. This configuration agrees with data from articulated specimens and trackways. As with sauropods, this metacarpal configuration makes retention of phalanges awkward for locomotion and may be functionally related to the vestigiality of the manual phalanges of the outer digits.

Evidence for a sauropod−like metacarpal configuration in ankylosaurian dinosaurs

Philip J. Senter — Tue, 18 Sep 2012 12:15:15 PDT

Ankylosaurian dinosaurs are armored, quadrupedal members of the ornithischian clade Thyreophora. Ankylosaurs are typically portrayed with the metacarpals slanted and distally divergent, with their proximal ends arranged in a shallow arc, both in the literature (Matthew 1922; Gaston et al. 2001; McCrea et al. 2001; Vickaryous et al. 2004) and in museum mounts (Fig. 1). In contrast, Carpenter (1984) illustrated the metacarpals of the ankylosaur Sauropelta edwardsorum Ostrom, 1970, from the Lower Cretaceous Cloverly Formation of Wyoming and Montana, with their proximal ends arranged in a tight, semicircular arc, but even in that depiction themetacarpals were slanted and distally divergent. Members of the thyreophoran clade Stegosauria, the sister taxon to the Ankylosauria (Butler et al. 2008), have also typically been portrayed with slanted and distally divergent metacarpals (Marsh 1891; Gilmore 1914; Galton and Upchurch 2004). Some researchers expressed the opinion that stegosaur metacarpals were held vertically, not distally divergent, with their proximal ends arranged in a tight, semicircular arc, so that the metacarpus formed a vertical half−tube (von Huene 1931; Thulborn 1990; Christiansen 1997) such that flexion of digit I would move it toward digit V. Manual manipulation of stegosaurian metacarpals has since confirmed that this is the correct configuration of the stegosaurian metacarpus (Senter 2010).Here I investigate the possibility that the ankylosaurian metacarpus exhibited a similar configuration. As in the previous study on stegosaurs (Senter 2010), I treat the slanting and spreading configuration and the vertical semi−tubular configuration as competing hypotheses, each with a set of testable predictions. Each hypothesis of metacarpal configuration in ankylosaurs predicts that the configuration (1) is allowed by the shapes of the metacarpals, (2) provides a better fit (alignment and contact of opposing articular surfaces) between the metacarpals than the competing hypothesis, (3) does not compromise the goodness of fit between the metacarpals and the phalanges, (4) is not contradicted by articulated specimens, and (5) agrees with ichnological evidence. In the previous study on stegosaurs I included an additional prediction: that the configuration provides sufficient support for and does not disarticulate the more proximal forelimb bones. Here, that prediction is omitted, because the ankylosaurian carpus is unknown (Vickaryous et al. 2004) except for a single carpal described by Maleev (1954).

Vestigial structures in the appendicular skeletons of eight African skink species (Squamata, Scincidae)

J. G. Moch et al. — Tue, 18 Sep 2012 12:15:14 PDT

Limb reduction and loss, with reduction of limb and girdle skeletons to a vestigial state, has occurred several times independently within the skink family (Scincidae). The vestigial appendicular skeletons of most limbless skinks have not been described before now. Here we describe those of eight African skink species, all with a burrowing lifestyle: Acontias percivali, Acontias meleagris, Typhlosaurus cregoi, Typhlosaurus lineatus, Typhlacontias gracilis, Sepsina bayonii, Scelotes anguina and Scelotes arenicola. For all but two (A. meleagris and Sc. arenicola) the appendicular skeletons were previously undescribed. Limbs are absent in all specimens except for vestigial hindlimbs in Se. bayonii and vestigial femurs in one specimen of Sc. arenicola. In our sample, the pectoral girdle is reduced to a pair of tiny slivers in A. percivali, Ty. gracilis, Se. bayonii and Sc. anguina. It is absent in the other specimens. The pelvic girdle is absent in Ty. cregoi. In all the rest but Se. bayonii it is vestigial, retaining only the ilium in A. meleagris, Ty. lineatus and one specimen of Sc. arenicola. This study adds to the number of skink species with vestigial appendicular skeletons that have been described. It also adds to the rangeof documented intraspecific variation in the vestigial appendicular skeletons of A. meleagris, Sc. arenicola and the Australian skinks Lerista stylis and Lerista carpentariae. We observed asymmetry between the left and right sides in the vestigial appendicular skeletons of four of the African skink species: A. meleagris, Sc. anguina, Sc. arenicola and Se. bayonii

New Dromaeosaurids (Dinosauria: Theropoda) from the Lower Cretaceous of Utah, and the Evolution of the Dromaeosaurid Tail

Philip J. Senter et al. — Tue, 18 Sep 2012 12:15:12 PDT

Background: The Yellow Cat Member of the Cedar Mountain Formation (Early Cretaceous, Barremian? – Aptian) of Utah has yielded a rich theropod fauna, including the coelurosaur Nedcolbertia justinhofmanni, the therizinosauroid Falcarius utahensis, the troodontid Geminiraptor suarezarum, and the dromaeosaurid Utahraptor ostrommaysorum. Recent excavation has uncovered three new dromaeosaurid specimens. One specimen, which we designate the holotype of the new genus and species Yurgovuchia doellingi, is represented by a partial axial skeleton and a partial left pubis. A second specimen consists of a right pubis and a possibly associated radius. The third specimen consists of a tail skeleton that is unique among known Cedar Mountain dromaeosaurids.

Methodology/Principal Findings: Y. doellingi resembles Utahraptor ostrommaysorum in that its caudal prezygapophyses are elongated but not to the degree present in most dromaeosaurids. The specimen represented by the right pubis exhibits a pronounced pubic tubercle, a velociraptorine trait that is absent in Y. doellingi. The specimen represented by the tail skeleton exhibits the extreme elongation of the caudal prezygapophyses that is typical of most dromaeosaurids. Here we perform a phylogenetic analysis to determine the phylogenetic position of Y. doellingi. Using the resulting phylogeny as a framework, we trace changes in character states of the tail across Coelurosauria to elucidate the evolution of the dromaeosaurid tail.

Conclusions/Significance: The new specimens add to the known diversity of Dromaeosauridae and to the known diversity within the Yellow Cat paleofauna. Phylogenetic analysis places Y. doellingi in a clade with Utahraptor, Achillobator, and Dromaeosaurus. Character state distribution indicates that the presence of intermediate-length caudal prezygapophyses in that clade is not an evolutionarily precursor to extreme prezygapophyseal elongation but represents a secondary shortening of caudal prezygapophyses. It appears to represent part of a trend within Dromaeosauridae that couples an increase in tail flexibility with increasing size.

More “dinosaur” and “pterosaur” rock art that isn’t

Philip J. Senter — Tue, 18 Sep 2012 12:15:11 PDT

To support claims of the coexistence of humans with dinosaurs and pterosaurs, young-earth creationist authors have identified several pieces of ancient rock art as depictions of dinosaurs or pterosaurs. Here, nine such claims are investigated. An alleged pterosaur painting in Black Dragon Canyon, Utah, is actually not a single painting. Its “head” and “neck” are a painting of a person with outstretched arms. Its torso and limbs are those of a painting of a second person with outstretched arms, whose body continues into the “pterosaur’s” “wing.” The other “wing” is a painting of a horned serpent. The three paintings only appear connected because someone outlined the group with chalk. An alleged dinosaur petroglyph in Havasupai Canyon, Arizona, is a stylized bird with an extension on one foot; the hooked line that represents its head and neck is a stylized bird head. A second alleged dinosaur petroglyph in Havasupai Canyon is a stylized bighorn sheep or rabbit. An alleged dinosaur cave painting in Tanzania is an obvious giraffe. Three alleged cave paintings of long-necked dinosaurs in Zambia have short necks and most likely represent lizards. An alleged dinosaur painting on Agawa Rock in Lake Superior Provincial Park, Ottawa, represents Underwater Panther,a supernatural lake guardian of Ojibwe tradition. An alleged pterosaur painting at Alton, Illinois, is the product of the imagination of a nineteenth-century American author. These pieces of rock art now join the ever-growing pile of discredited “evidence”for the ancient coexistence of humans and dinosaurs

Using creation science to demonstrate evolution 2: morphological continuity within Dinosauria

Philip J. Senter — Tue, 18 Sep 2012 12:15:11 PDT

Creationist literature claims that sufficient gaps in morphological continuity exist to classify dinosaurs into several distinct baramins (‘created kinds’). Here, I apply the baraminological method called taxon correlation to test for morphological continuity within and between dinosaurian taxa. The results show enough morphological continuity within Dinosauria to consider most dinosaurs genetically related, even by this creationist standard. A continuous morphological spectrum unites the basal members of Saurischia, Theropoda, Sauropodomorpha, Ornithischia, Thyreophora, arginocephalia, and Ornithopoda with Nodosauridae and Pachycephalosauria and with the basal ornithodirans Silesaurus and Marasuchus. Morphological gaps in the known fossil record separate only seven groups from the rest of Dinosauria. Those groups are Therizinosauroidea + Oviraptorosauria + Paraves, Tazoudasaurus + Eusauropoda, Ankylosauridae, Stegosauria, Neoceratopsia, basal Hadrosauriformes and Hadrosauridae. Each of these seven groups exhibits within-group morphological continuity, indicating common descent for all the group’s members, even according to this creationist standard.