45 research outputs found

    Crown size comparisons in patients with unilateral palatally displaced canines

    Get PDF
    Abstract CROWN SIZE COMPARISONS IN PATIENTS WITH PALATALLY DISPLACED CANINES By Joseph L. Eliason, D.D.S. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University. Virginia Commonwealth University, 2015 Thesis Director: Steven J. Lindauer, D.M.D., M.Dent.Sc. Professor and Chair, Department of Orthodontics There has been significant debate over the past decades regarding the etiology of palatally displaced canines. Theorized risk factors include agenesis or malformation of the lateral incisors, incisor retroclination, transverse deficiency, or genetic predisposition. The purpose of this study is to compare the linear and volumetric measurements of canines and lateral incisors to determine how tooth size relates to canine impaction. Cone-beam CT images for 40 patients with unilateral palatally displaced canines were utilized to measure the linear dimensions and total crown volume of canines and lateral incisors and to compare those teeth on the impaction side with their isomers on the non-impaction side. Results showed that unilateral palatally impacted maxillary canine crowns were slightly, but statistically significantly wider and larger in volume than their non-impacted isomers. Lateral incisor crowns adjacent to impacted canines were significantly shorter than those adjacent to non-impacted canines

    The female partners’ perspective on vasectomy in the central region of Ghana

    Get PDF
    Background: Vasectomy is one of the safest and inexpensive modern contraceptive methods but it remains relatively‘invisible’ in Ghana. Support of women may be a significant incentive in influencing their partners to adopt vasec- tomy.Objective: To examine the perspectives of women on vasectomy as a contraceptive option.Materials and Methods: A cross-sectional survey was conducted among 298 women accessing long-term or perma- nent family planning methods at health facilities in three selected districts in the Central Region of Ghana. Pearson’s Chi-square was used to test associations between variables and the attitudes of women towards vasectomy. A p-value of less than 0.05 was considered to be statistically significantResults: Awareness of vasectomy was low (32%). About 66% of the women who became aware of vasectomy during the study would prefer their partners to go for vasectomy compared with 50% of those who were aware prior to the study. Women who would either not prefer vasectomy or support their partner’s choice of vasectomy cited fear of impotency (39.6%). There was a statistically significant association (p<0.05) between ethnicity, previous contracep- tive use, awareness of male methods, and preference for vasectomy instead of bilateral tubal ligation (BTL). A statis- tically significant association (p<0.05) was also found between age of participant, duration of marriage, religious affiliation, and the willingness of women to support their partner’s choice of vasectomy.Conclusion: There is, therefore, the need for the involvement of women in the promotion of vasectomy through vigorous publicity and education.Funding: By authorsKeywords: vasectom , tubal, contraceptive agents, Ghana, sterilizatio

    Interspecific hybridization explains rapid gorget colour divergence in Heliodoxa hummingbirds (Aves: Trochilidae)

    Get PDF
    Hybridization is a known source of morphological, functional and communicative signal novelty in many organisms. Although diverse mechanisms of established novel ornamentation have been identified in natural populations, we lack an understanding of hybridization effects across levels of biological scales and upon phylogenies. Hummingbirds display diverse structural colours resulting from coherent light scattering by feather nanostructures. Given the complex relationship between feather nanostructures and the colours they produce, intermediate coloration does not necessarily imply intermediate nanostructures. Here, we characterize nanostructural, ecological and genetic inputs in a distinctive Heliodoxa hummingbird from the foothills of eastern Peru. Genetically, this individual is closely allied with Heliodoxa branickii and Heliodoxa gularis, but it is not identical to either when nuclear data are assessed. Elevated interspecific heterozygosity further suggests it is a hybrid backcross to H. branickii. Electron microscopy and spectrophotometry of this unique individual reveal key nanostructural differences underlying its distinct gorget colour, confirmed by optical modelling. Phylogenetic comparative analysis suggests that the observed gorget coloration divergence from both parentals to this individual would take 6.6–10 My to evolve at the current rate within a single hummingbird lineage. These results emphasize the mosaic nature of hybridization and suggest that hybridization may contribute to the structural colour diversity found across hummingbirds

    Behavioral, cognitive, and adaptive development in infants with autism spectrum disorder in the first 2 years of life

    Get PDF
    BackgroundTo delineate the early progression of autism spectrum disorder (ASD) symptoms, this study investigated developmental characteristics of infants at high familial risk for ASD (HR), and infants at low risk (LR).MethodsParticipants included 210 HR and 98 LR infants across 4 sites with comparable behavioral data at age 6, 12, and 24months assessed in the domains of cognitive development (Mullen Scales of Early Learning), adaptive skills (Vineland Adaptive Behavioral Scales), and early behavioral features of ASD (Autism Observation Scale for Infants). Participants evaluated according to the DSM-IV-TR criteria at 24months and categorized as ASD-positive or ASD-negative were further stratified by empirically derived cutoff scores using the Autism Diagnostic Observation Schedule yielding four groups: HR-ASD-High, HR-ASD-Moderate (HR-ASD-Mod), HR-ASD-Negative (HR-Neg), and LR-ASD-Negative (LR-Neg).ResultsThe four groups demonstrated different developmental trajectories that became increasingly distinct from 6 to 24months across all domains. At 6months, the HR-ASD-High group demonstrated less advanced Gross Motor and Visual Reception skills compared with the LR-Neg group. By 12months, the HR-ASD-High group demonstrated increased behavioral features of ASD and decreased cognitive and adaptive functioning compared to the HR-Neg and LR-Neg groups. By 24months, both the HR-ASD-High and HR-ASD-Moderate groups demonstrated differences from the LR- and HR-Neg groups in all domains.ConclusionsThese findings reveal atypical sensorimotor development at 6months of age which is associated with ASD at 24months in the most severely affected group of infants. Sensorimotor differences precede the unfolding of cognitive and adaptive deficits and behavioral features of autism across the 6- to 24-month interval. The less severely affected group demonstrates later symptom onset, in the second year of life, with initial differences in the social-communication domain.Electronic supplementary materialThe online version of this article (doi:10.1186/s11689-015-9117-6) contains supplementary material, which is available to authorized users

    Energy Reallocation to Breeding Performance through Improved Nest Building in Laboratory Mice.

    Get PDF
    Mice are housed at temperatures (20-26°C) that increase their basal metabolic rates and impose high energy demands to maintain core temperatures. Therefore, energy must be reallocated from other biological processes to increase heat production to offset heat loss. Supplying laboratory mice with nesting material may provide sufficient insulation to reduce heat loss and improve both feed conversion and breeding performance. Naïve C57BL/6, BALB/c, and CD-1breeding pairs were provided with bedding alone, or bedding supplemented with either 8g of Enviro-Dri, 8g of Nestlets, for 6 months. Mice provided with either nesting material built more dome-like nests than controls. Nesting material improved feed efficiency per pup weaned as well as pup weaning weight. The breeding index (pups weaned/dam/week) was higher when either nesting material was provided. Thus, the sparing of energy for thermoregulation of mice given additional nesting material may have been responsible for the improved breeding and growth of offspring

    Malaria vector research and control in Haiti: a systematic review

    Get PDF
    BACKGROUND: Haiti has a set a target of eliminating malaria by 2020. However, information on malaria vector research in Haiti is not well known. This paper presents results from a systematic review of the literature on malaria vector research, bionomics and control in Haiti. METHODS: A systematic search of literature published in French, Spanish and English languages was conducted in 2015 using Pubmed (MEDLINE), Google Scholar, EMBASE, JSTOR WHOLIS and Web of Science databases as well other grey literature sources such as USAID, and PAHO. The following search terms were used: malaria, Haiti, Anopheles, and vector control. RESULTS: A total of 132 references were identified with 40 high quality references deemed relevant and included in this review. Six references dealt with mosquito distribution, seven with larval mosquito ecology, 16 with adult mosquito ecology, three with entomological indicators of malaria transmission, eight with insecticide resistance, one with sero-epidemiology and 16 with vector control. In the last 15 years (2000–2015), there have only been four published papers and three-scientific meeting abstracts on entomology for malaria in Haiti. Overall, the general literature on malaria vector research in Haiti is limited and dated. DISCUSSION: Entomological information generated from past studies in Haiti will contribute to the development of strategies to achieve malaria elimination on Hispaniola. However it is of paramount importance that malaria vector research in Haiti is updated to inform decision-making for vector control strategies in support of malaria elimination

    Henry A. Kissinger as Negotiator: Background and Key Accomplishments

    Full text link

    Behavioral, cognitive, and adaptive development in infants with autism spectrum disorder in the first 2 years of life

    Get PDF
    BACKGROUND: To delineate the early progression of autism spectrum disorder (ASD) symptoms, this study investigated developmental characteristics of infants at high familial risk for ASD (HR), and infants at low risk (LR). METHODS: Participants included 210 HR and 98 LR infants across 4 sites with comparable behavioral data at age 6, 12, and 24 months assessed in the domains of cognitive development (Mullen Scales of Early Learning), adaptive skills (Vineland Adaptive Behavioral Scales), and early behavioral features of ASD (Autism Observation Scale for Infants). Participants evaluated according to the DSM-IV-TR criteria at 24 months and categorized as ASD-positive or ASD-negative were further stratified by empirically derived cutoff scores using the Autism Diagnostic Observation Schedule yielding four groups: HR-ASD-High, HR-ASD-Moderate (HR-ASD-Mod), HR-ASD-Negative (HR-Neg), and LR-ASD-Negative (LR-Neg). RESULTS: The four groups demonstrated different developmental trajectories that became increasingly distinct from 6 to 24 months across all domains. At 6 months, the HR-ASD-High group demonstrated less advanced Gross Motor and Visual Reception skills compared with the LR-Neg group. By 12 months, the HR-ASD-High group demonstrated increased behavioral features of ASD and decreased cognitive and adaptive functioning compared to the HR-Neg and LR-Neg groups. By 24 months, both the HR-ASD-High and HR-ASD-Moderate groups demonstrated differences from the LR- and HR-Neg groups in all domains. CONCLUSIONS: These findings reveal atypical sensorimotor development at 6 months of age which is associated with ASD at 24 months in the most severely affected group of infants. Sensorimotor differences precede the unfolding of cognitive and adaptive deficits and behavioral features of autism across the 6- to 24-month interval. The less severely affected group demonstrates later symptom onset, in the second year of life, with initial differences in the social-communication domain. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s11689-015-9117-6) contains supplementary material, which is available to authorized users

    The High Resolution Imaging Science Experiment (HiRISE) during MRO’s Primary Science Phase (PSP)

    Full text link
    corecore