The influence of pigmentation patterning on bumblebee foraging from flowers of <em>Antirrhinum majus</em>

Patterns of pigmentation overlying the petal vasculature are common in flowering plants and have been postulated to play a role in pollinator attraction. Previous studies report that such venation patterning is significantly more attractive to bee foragers in the field than ivory or white flowers without veins. To dissect the ways in which venation patterning of pigment can influence bumblebee behaviour, we investigated the response of flower-naïve individuals of Bombus terrestris to veined, ivory and red near-isogenic lines of Antirrhinum majus. We find that red venation shifts flower colour slightly, although the ivory background is the dominant colour. Bees were readily able to discriminate between ivory and veined flowers under differential conditioning but showed no innate preference when presented with a free choice of rewarding ivory and veined flowers. In contrast, both ivory and veined flowers were selected significantly more often than were red flowers. We conclude that advantages conferred by venation patterning might stem from bees learning of their use as nectar guides, rather than from any innate preference for striped flowers. © 2013 Springer-Verlag Berlin Heidelberg

A Dynamic Bioeconomic Model of Ivory Trade: Details and Extended Results

Trade in ivory is banned under CITES in an effort to protect the African elephant. The trade ban is supported by some range states, most notably Kenya, because they see the ban as an effective means for protecting a ‘flagship’ species, one that attracts tourists and foreign aid. It is opposed by some states, mainly in southern Africa, because their elephant populations are exceeding the capacity of local ecosystems with culling and other sources have resulted in the accumulation of large stocks of ivory. They argue that ivory trade will benefit elephant populations. The question of whether an ivory trade ban will protect elephant populations is addressed in this paper using a dynamic partial-equilibrium model that consists of four ivory exporting regions and a single demand region. Results indicate that a trade ban might not be successful in maintaining elephant populations, even if it leads to a stigma effect that reduces demand and increases the marginal costs of marketing ivory. The modeling results suggest that the species will survive only if the non-market value of elephants is taken into account. If rich countries compensate African range states according to marginal willingness to pay for elephants, optimal populations are lower than under an average payment, and, perhaps surprisingly, the interaction between tourism benefits and marginal compensation can lead to the demise of elephants in some regions where this would not occur otherwise. Finally, elephant populations are even projected to crash if range states can operate an effective quota scheme, even one that excludes poaching. Free trade in ivory and effective institutions that translate numbers of elephants into monetary payments may be the best hope for the elephant.economics of elephant conservation, economics of ivory trade, trade bans, cartels and quota

Characterization of dentine to assess bond strength of dental composites

This study was performed to develop alternating dentine adhesion models that could help in the evaluation of a self-bonding dental composite. For this purpose dentine from human and ivory was characterized chemically and microscopically before and after acid etching using Raman and SEM. Mechanical properties of dentine were determined using 3 point bend test. Composite bonding to dentine, with and without use of acid pre-treatment and/or the adhesive, were assessed using a shear bond test. Furthermore, micro gap formation after restoration of 3 mm diameter cavities in dentine was assessed by SEM. Initial hydroxyapatite level in ivory was half that in human dentine. Surface hydroxyapatites decreased by approximately half with every 23 s of acid etch. The human dentine strength (56 MPa) was approximately double that of ivory, while the modulus was almost comparable to that of ivory. With adhesive use, average shear bond strengths were 30 and 26 MPa with and without acid etching. With no adhesive, average bond strength was 6 MPa for conventional composites. This, however, increased to 14 MPa with a commercial flowable "self-bonding" composite or upon addition of low levels of an acidic monomer to the experimental composite. The acidic monomer additionally reduced micro-gap formation with the experimental composite. Improved bonding and mechanical properties should reduce composite failures due to recurrent caries or fracture respectively

Carved Ivory Puzzle Balls

The Chinese Carved Ivory Puzzle Balls reference the interest in combing art and nature while designating curiosity in Chinese craftsmanship and imagery affecting a European market.The Chinese Ivory Carved Puzzle Balls have been beloved items in the Gettysburg College collection since they were donated in 1959 by Frank Kramer and John Hampshire. The Puzzle Balls, featuring nine balls were displayed in the Schmucker Hall Library. Alumni love the items and regularly ask about the collection in Special Collections as they represent an aspect of the college they continue to love. [excerpt

Towards the attainment of self-sustaining growth: Ghana and the Ivory Coast

Ghana and the Ivory Coast are two neighbouring states of the West Coast of Africa so similar in size, geography, resource endowment, stage of economic development in terms of per capita income and capacity to develop at the date of independence (Ghana 1957 and Ivory Coast 1960), that a comparison of the results of the economic policies adopted and the political orientation followed by each of them has ever been a big challenge. While Ghana had at the time of independence almost twice the population of Ivory Coast, the agricultural sector had similar importance accounting for more than 40 percent of GDP, the industrial sector for less than 10 percent. The principal agricultural export crops were the same: cocoa, coffee and wood and the importance of external trade was also similar, amounting to about 30 percent of GDP in each country in 1960 (table 1). But while in Ghana cocoa was by far the most important export product it was coffee in the case of Ivory Coast.

Eliminating Excessive and Unfair Exclusionary Discipline in Schools Policy Recommendations for Reducing Disparities

All schools must be safe places for all members of the learning community. Schools have the right and indeed the responsibility to develop safe school climates to protect the safety of students and teachers, as well as the integrity of learning Yet the data indicate that it is relatively rare for students to pose a serious danger to themselves or others.In states like Texas, serious safety concerns trigger a "non-discretionary" mandatory removal, but these represent less than 5% of all disciplinary removals from school. While exclusion on grounds of safety is infrequent, students are routinely removed from school for minor offenses like tardiness, truancy, using foul language, disruption, and violation of the dress code.Of course, public school educators are also responsible for ensuring the integrity of the learning environment and attend to misbehavior that does not raise safety concerns. There is no question that there are circumstances where removing a student from a classroom is helpful to de-escalate a conflict, or to pursue an intervention outside the classroom with the support of an administrator, a counselor, parent(s) or community members. However, too many of our nation's public schools have moved away from reserving school exclusion only for the most serious offenses, and as a measure of last resort. Excessive suspensions and expulsions threaten educational opportunity, thereby undermining our national goals for closing academic achievement gaps for all children

Inbreeding ratio and genetic relationships among strains of the Western clawed frog, Xenopus tropicalis

The Western clawed frog, Xenopus tropicalis, is a highly promising model amphibian, especially in developmental and physiological research, and as a tool for understanding disease. It was originally found in the West African rainforest belt, and was introduced to the research community in the 1990s. The major strains thus far known include the Nigerian and Ivory Coast strains. However, due to its short history as an experimental animal, the genetic relationship among the various strains has not yet been clarified, and establishment of inbred strains has not yet been achieved. Since 2003 the Institute for Amphibian Biology (IAB), Hiroshima University has maintained stocks of multiple X. tropicalis strains and conducted consecutive breeding as part of the National BioResource Project. In the present study we investigated the inbreeding ratio and genetic relationship of four inbred strains at IAB, as well as stocks from other institutions, using highly polymorphic microsatellite markers and mitochondrial haplotypes. Our results show successive reduction of heterozygosity in the genome of the IAB inbred strains. The Ivory Coast strains clearly differed from the Nigerian strains genetically, and three subgroups were identified within both the Nigerian and Ivory Coast strains. It is noteworthy that the Ivory Coast strains have an evolutionary divergent genetic background. Our results serve as a guide for the most effective use of X. tropicalis strains, and the long-term maintenance of multiple strains will contribute to further research efforts

Shining NIR light on ivory: a practical enforcement tool for elephant ivory identification

The elephant ivory trade remains controversial because of concerns about the extinction risk of elephants and the different needs of CITES member states. Thailand's situation is particularly contentious because of the different legal status among types of elephant ivory. Thai law allows the local sale of ivory from domesticated Asian elephants, which creates challenges for Thai enforcement officers in identification of ivory provenance. We investigated the capacity of non-destructive Near Infrared (NIR) spectroscopy (600–1700 nm), combined with Partial Least Squares Discriminant Analysis (PLS-DA), to discriminate between ivory from African, wild Asian and domesticated Asian elephants. Ivory spectra of 64 elephants were divided randomly into calibration and validation datasets. We were able to determine elephant ivory provenance at both the interspecies (African and Asian elephant ivory), and within species (wild and domesticated Asian elephant ivory) classifications with 100% accuracy. These results showed the potential use of handheld NIR spectrometers for rapid assessments of ivory provenance, as well as a forensic tool for wider enforcement

Elephants and the Ivory Trade Ban: Summary of Research Results

economics of elephant conservation, economics of ivory trade,trade bans