7,611 research outputs found

    Investigating user preferences in utilizing a 2D paper or 3D sketch based interface for creating 3D virtual models

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    Computer modelling of 2D drawings is becoming increasingly popular in modern design as can be witnessed in the shift of modern computer modelling applications from software requiring specialised training to ones targeted for the general consumer market. Despite this, traditional sketching is still prevalent in design, particularly so in the early design stages. Thus, research trends in computer-aided modelling focus on the the development of sketch based interfaces that are as natural as possible. In this report, we present a hybrid sketch based interface which allows the user to make draw sketches using offline as well as online sketching modalities, displaying the 3D models in an immersive setup, thus linking the object interaction possible through immersive modelling to the flexibility allowed by paper-based sketching. The interface was evaluated in a user study which shows that such a hybrid system can be considered as having pragmatic and hedonic value.peer-reviewe

    Blood vessel growth in primate retinal development: Relationship of retinal maturation with choriocapillaris growth and a role for TGF-β in the retina.

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    Background: The development of the blood supply in the primate retina has been extensively studied; however the relationship of the differentiating retina to the choroidal blood supply is less well known. The interaction of astrocytes and vascular endothelial cells promotes the development of the retinal vasculature from 14 weeks’ gestation (WG). Initially, astrocytes lead the developing capillaries from the optic nerve towards the macular area. However, neither astrocytes nor endothelial cells enter a prescribed avascular area, within which the fovea later forms. This may be attributed to expression of a factor that inhibits astrocyte and endothelial cell proliferation in the fovea. A factor found in the CNS that is already known to have these effects is transforming growth factor-β (TGF-β). Aims: This thesis investigated the relationship between retinal maturation and choroidal blood vessel supply and the possible role for TGF-β as an antiangiogenic factor in maintaining an avascular fovea during primate retinal development. Methods: Human eyes between 11 WG and 40 years were obtained with ethical approval from Prince of Wales Hospital and the NSW Lions Eye Bank and fixed and sectioned for histological procedures or prepared for polymerase chain reaction (PCR). Macaque eyes from foetal day (fd) 64 to postnatal 11years (p11y) were obtained from Bogor Agriculture University, Indonesia with the approval of the Ethics Committee of the University of Washington, Seattle, USA. Macaque eyes were also fixed and sectioned for immunohistochemistry and in situ hybridisation. RNA was extracted from human foetal retinas and used for RTPCR (Reverse Transcriptase PCR), QPCR (Quantitative PCR) and preparation of riboprobes. PCR products were analysed using both restriction digest and sequencing. RTPCR was used to identify TGF-β1, TGF-β2 and TGF-β3 in the developing human and in the developing and adult macaque retinas whilst QPCR was used to quantify the TGF-β isoforms in central compared to peripheral retina and in foetal compared to adult retina. In situ hybridisation was performed according to a standard protocol and visualised using Roche HNPP Fast Red detection set with designed riboprobes for TGF-β1, TGF-β2 and TGF-β3 (DIG RNA labelling kit). Some sections were counterstained with vimentin antibody. Immunohistochemistry was performed on human retina and choroid sections using antibodies to CD34 and Ki67 and on human and macaque retina using antibodies to synaptophysin, vimentin, GFAP, calbindin, S-opsin, RG-opsin, rhodopsin, TGF-β1, TGF-β2, TGF-β3 and their receptors TβRI and TβRII. Sections of the retina were imaged and analysed using either a Leica Confocal microscope and TCSNT software or Zeiss Confocal microscope and LSM 5 Pascal software. Data from the human retina and choroid sections corresponding to different regions (foveal, parafoveal nasal, parafoveal temporal, nasal and temporal) was collected to measure the number of Ki-67 immunolabelled mitotic endothelial cells and the area of CD34 immunolabelled choriocapillaris using Adobe Photoshop version 5.0.2, NIH software version 1.62 (measurement macros) and Excel. In the human and macaque sections the intensity of TGF-β protein and mRNA expression was captured from different regions of the retina (foveal, parafoveal nasal, parafoveal temporal, nasal, temporal, nasal to disc) to compile montages. Montages were then re-imported into LSM 5 Pascal software to measure the optical density across each montage along the ganglion cell layer, outer neuroblastic zone and photoreceptor layer collecting data in Excel for graphical representation. In addition to the montages, individual sections were assessed for co-localisation of TGF-β and TβR to various retinal cell types. Results: Analyses of choriocapillaris area and endothelial cell (EC) proliferation were able to demonstrate that the area of choriocapillaris endothelium is greater in the foveal region at all ages (14-18.5WG), that the rate of choriocapillaris EC proliferation declines dramatically over this same period and that the lowest rates of EC proliferation are at the incipient fovea. Most importantly these findings indicate that EC proliferation in the choriocapillaris does not appear to be promoted by increased metabolic activity in central retinal neurons which are more developed with higher oxygen and nutrient demands, which is the mechanism widely thought to regulate development of the retinal vasculature. PCR showed all TGF-β isoforms to be present in the human developing and adult retina. QPCR revealed that TGF-β2 was the most predominant isoform, followed by TGF-β3 with very small amounts of TGF-β1 seen. The isoforms were more abundant in developing rather than adult retina and in central rather than peripheral retina. Studies of the distribution of TGF-β protein and mRNA using immunohistochemistry and in situ hybridisation confirmed the low levels of TGF-β1 protein and mRNA observed in QPCR and demonstrated distinct centroperipheral gradients in the photoreceptor layer for TGF-β2 and TGF-β3. Relative high amounts of TGF-β in the fovea could affect vascular patterning due to TβRI seen in astrocytes which lead the blood vessels at the foveal rim at the level of the ganglion cell plexus. TGF-β2 and TGF-β3 expression is detected before formation of the foveal avascular zone (FAZ) at fd64 (~15WG) - fd73 (~17WG) with levels peaking in the foveal region at fd105 (~25WG) by the time the FAZ forms. Conclusions: This thesis has shown that EC proliferation in the choriocapillaris does not appear to be promoted by increased metabolic activity in central retinal neurons as reduced rates of EC proliferation in the ‘foveal’ chorioretinal location were observed at all ages studied between 14 and 18.5WG. The findings suggest that mechanisms regulating proliferation and growth of the choroidal vasculature are independent of differentiation in the neural retina and are therefore different to those governing the formation of the retinal vasculature. All TGF-β isoforms are expressed in developing and adult human and macaque retina with TGF-β2 being the predominant isoform. TGF-β isoforms are more abundant in central compared to peripheral retina and in developing compared to adult retina. Centro-peripheral gradients of TGF-β2 and TGF-β3 across the photoreceptor layer and TβRI on astrocytes support the presence of TGF-β in the fovea as an antiproliferative and antiangiogenic factor by helping to define the FAZ early in development, well before 23-25 WG in humans and before fd100 in macaques

    REVIEW AND EVALUATION OF RELIABILITY GENERALIZATION RESEARCH

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    Reliability Generalization (RG) is a meta-analytic method that examines the sources of measurement error variance for scores for multiple studies that use a certain instrument or group of instruments that measure the same construct (Vacha-Haase, Henson, & Caruso, 2002). Researchers have been conducting RG studies for over 10 years since it was first discussed by Vacha-Haase (1998). Henson and Thompson (2002) noted that, as RG is not a monolithic technique; researchers can conduct RG studies in a variety of ways and include diverse variables in their analyses. Differing recommendations exist in regards to how researchers should retrieve, code, and analyze information when conducting RG studies and these differences can affect the conclusions drawn from meta-analytic studies (Schmidt, Oh, & Hayes, 2009) like RG. The present study is the first comprehensive review of both current RG practices and RG recommendations. Based upon the prior research findings of other meta-analytic review papers (e.g., Dieckmann, Malle, & Bodner 2009), the overarching hypothesis was that there would be differences between current RG practices and best practice recommendations made for RG studies. Data consisted of 64 applied RG studies and recommendation papers, book chapters, and unpublished papers/conference papers. The characteristics that were examined included how RG researchers: (a) collected studies, (b) organized studies, (c) coded studies, (d) analyzed their data, and (e) reported their results. The results showed that although applied RG researchers followed some of the recommendations (e.g., RG researchers examined sample characteristics that influenced reliability estimates), there were some recommendations that RG researchers did not follow (e.g., the majority of researchers did not conduct an a priori power analysis). The results can draw RG researchers’ attentions to areas where there is a disconnect between practice and recommendations as well as provide a benchmark for assessing future improvement in RG implementation

    Population Response to Climate Change: Wintering Strategy has Carryover Effects on the Timing of Nest Initiation and Mate Choice in a Partial Migrant, the American Kestrel (\u3cem\u3eFalco sparverius\u3c/em\u3e)

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    The ability of a population to respond to climate change will depend on phenotypic plasticity, adaptation, or both. Bird populations have already responded to warming temperatures by shifting their distributions, adjusting migration distance and timing, and breeding earlier. A population of American kestrels (Falco sparverius) in southwestern Idaho has advanced its nesting by approximately 30 days, on average, in the last 30 years and this has been correlated with changes in winter climate. The mechanisms allowing for this shift, however, are not clearly understood. I investigated if assortative mating of wintering kestrels and non-wintering kestrels is accompanying to this shift by monitoring kestrels in the winter and breeding seasons from 2010-2013. I asked if 1) wintering kestrels nest earlier than non-wintering kestrels, 2) wintering kestrels tend to mate with wintering kestrels and non-wintering kestrels mate with non-wintering kestrels, and 3) early breeding kestrels are genetically differentiated from late breeding kestrels. Results indicate that wintering kestrels nest earlier than non-wintering kestrels but this effect varies across years. Wintering strategy of females significantly predicted the wintering strategy of its mate which provides evidence for assortative mating. Analysis of 6 polymorphic microsatellite loci, however, gave no evidence of genetic differentiation or genetic structure between early and late breeding kestrels. This could be because there is still mixing between the groups despite differences in phenology, or the assortative mating pattern has arisen too recently to have resulted in genetic differentiation. Overall, this study documents that there are carryover effects of wintering strategy on the timing of nest initiation and mate pairing in American kestrels. It provides evidence for assortative mating of kestrels by wintering strategy, but this assortative mating has not lead to genetic divergence in kestrels of southwestern Idaho at this time

    The Influence of Assimilated Targeted Observations Upon Ensemble Forecasts of Convection Initiation

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    The influence of assimilating targeted meso-Îą- to synoptic-scale observations collected in the upstream, pre-convective environment upon subsequent short-range ensemble forecasts of convection initiation (CI) across the central United States for the fifteen aircraft missions conducted by the Mesoscale Predictability Experiment (MPEX) in May and June 2013 is evaluated in this study. Utilizing the ensemble Kalman filter implementation within the Data Assimilation Research Testbed software package as coupled to version 3.4.1 of the Advanced Research version of the Weather Research and Forecasting model, two nearly-identical thirty- member ensembles of short-range forecasts are conducted for each mission. Initial conditions for one ensemble are generated through a cycled data assimilation process that incorporates the targeted MPEX dropsonde observations from that day\u27s mission, and initial conditions for the other ensemble are generated through a cycled data assimilation process that excludes the targeted MPEX dropsonde observations. All forecasts for a given mission begin at 1500 UTC, extend forward 15 h, and are conducted on a domain encompassing the conterminous United States with 3 km horizontal grid spacing and 40 vertical levels. Verification is conducted over spatiotemporal thresholds of 50 km/0.5 h, 100 km/1 h, and 200 km/2 h of an observed CI event to assess the skill of probabilistic forecasts and quantify the influence that assimilating targeted observations has upon forecast skill for the events considered. Forecasts without the targeted observations have high probabilities of detection but also greatly overproduce CI, and the inclusion of targeted observations minimally improves some forecasts and minimally degrades other forecasts. Within the 100 km/1 h threshold, the targeted observations on average reduce distance errors between matched modeled and observed objects by 0.22 km while adding a time bias of 0.24 minutes. The forecast performance of specific cases as well as implications for CI predictability are discussed

    The Effects of Communication, Gender, and Sexism on Dating Initiations

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    The purpose of this study was to increase understanding of the initial screening process that occurs during dating interactions, and to measure the perceptions of different communication styles that individuals use during such interactions. A review of current literature focused on attractiveness of potential mates, ambivalent sexism theory, gender stereotypes, and communication theory. The present study examined how individuals view others’ approaches in initial dating interactions, and which of these approaches are most effective for increasing the target’s interest in spending time with the pursuer. A pilot study involving 45 undergraduate psychology students from Western Kentucky University was conducted to evaluate the validity of the Dating Initiation Questionnaire (DIQ), which was created for this study. In the final study, one hundred and fifty two undergraduate psychology students from Western Kentucky University completed measures of sexism, social desirability, and dating initiation preference. Results showed that both communication theory and ambivalent sexism theory were relevant in dating initiations. Consistent with previous communication research, assertive communication was rated as more effective than aggressive and passive communication in the initial interactions that occur in heterosexual dating initiations. This suggests it is best to use assertive communication as a first choice in dating interactions. Further analyses showed that females were more likely to rate assertive and passive initiations as more effective than aggressive dating initiations, while males were more likely than females to rate aggressive initiations as more effective than passive initiations, and to rate aggressive initiations as more effective than assertive initiations. Stronger ambivalent sexist beliefs were associated with higher ratings for aggressive dating initiations. Therefore, individuals who held negative attitudes toward non-traditional women and positive attitudes toward gender stereotypical women preferred aggressive dating initiations. Such individuals may approach others in an aggressive manner. One could argue that, to prevent such harassment, individuals should be educated about communication styles and gender equality. Future research should focus on applying such interventions to males and females, and on revising the intervention to suit individuals with sexist beliefs toward women and men

    Blood vessel growth in primate retinal development: Relationship of retinal maturation with choriocapillaris growth and a role for TGF-β in the retina.

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    Background: The development of the blood supply in the primate retina has been extensively studied; however the relationship of the differentiating retina to the choroidal blood supply is less well known. The interaction of astrocytes and vascular endothelial cells promotes the development of the retinal vasculature from 14 weeks’ gestation (WG). Initially, astrocytes lead the developing capillaries from the optic nerve towards the macular area. However, neither astrocytes nor endothelial cells enter a prescribed avascular area, within which the fovea later forms. This may be attributed to expression of a factor that inhibits astrocyte and endothelial cell proliferation in the fovea. A factor found in the CNS that is already known to have these effects is transforming growth factor-β (TGF-β). Aims: This thesis investigated the relationship between retinal maturation and choroidal blood vessel supply and the possible role for TGF-β as an antiangiogenic factor in maintaining an avascular fovea during primate retinal development. Methods: Human eyes between 11 WG and 40 years were obtained with ethical approval from Prince of Wales Hospital and the NSW Lions Eye Bank and fixed and sectioned for histological procedures or prepared for polymerase chain reaction (PCR). Macaque eyes from foetal day (fd) 64 to postnatal 11years (p11y) were obtained from Bogor Agriculture University, Indonesia with the approval of the Ethics Committee of the University of Washington, Seattle, USA. Macaque eyes were also fixed and sectioned for immunohistochemistry and in situ hybridisation. RNA was extracted from human foetal retinas and used for RTPCR (Reverse Transcriptase PCR), QPCR (Quantitative PCR) and preparation of riboprobes. PCR products were analysed using both restriction digest and sequencing. RTPCR was used to identify TGF-β1, TGF-β2 and TGF-β3 in the developing human and in the developing and adult macaque retinas whilst QPCR was used to quantify the TGF-β isoforms in central compared to peripheral retina and in foetal compared to adult retina. In situ hybridisation was performed according to a standard protocol and visualised using Roche HNPP Fast Red detection set with designed riboprobes for TGF-β1, TGF-β2 and TGF-β3 (DIG RNA labelling kit). Some sections were counterstained with vimentin antibody. Immunohistochemistry was performed on human retina and choroid sections using antibodies to CD34 and Ki67 and on human and macaque retina using antibodies to synaptophysin, vimentin, GFAP, calbindin, S-opsin, RG-opsin, rhodopsin, TGF-β1, TGF-β2, TGF-β3 and their receptors TβRI and TβRII. Sections of the retina were imaged and analysed using either a Leica Confocal microscope and TCSNT software or Zeiss Confocal microscope and LSM 5 Pascal software. Data from the human retina and choroid sections corresponding to different regions (foveal, parafoveal nasal, parafoveal temporal, nasal and temporal) was collected to measure the number of Ki-67 immunolabelled mitotic endothelial cells and the area of CD34 immunolabelled choriocapillaris using Adobe Photoshop version 5.0.2, NIH software version 1.62 (measurement macros) and Excel. In the human and macaque sections the intensity of TGF-β protein and mRNA expression was captured from different regions of the retina (foveal, parafoveal nasal, parafoveal temporal, nasal, temporal, nasal to disc) to compile montages. Montages were then re-imported into LSM 5 Pascal software to measure the optical density across each montage along the ganglion cell layer, outer neuroblastic zone and photoreceptor layer collecting data in Excel for graphical representation. In addition to the montages, individual sections were assessed for co-localisation of TGF-β and TβR to various retinal cell types. Results: Analyses of choriocapillaris area and endothelial cell (EC) proliferation were able to demonstrate that the area of choriocapillaris endothelium is greater in the foveal region at all ages (14-18.5WG), that the rate of choriocapillaris EC proliferation declines dramatically over this same period and that the lowest rates of EC proliferation are at the incipient fovea. Most importantly these findings indicate that EC proliferation in the choriocapillaris does not appear to be promoted by increased metabolic activity in central retinal neurons which are more developed with higher oxygen and nutrient demands, which is the mechanism widely thought to regulate development of the retinal vasculature. PCR showed all TGF-β isoforms to be present in the human developing and adult retina. QPCR revealed that TGF-β2 was the most predominant isoform, followed by TGF-β3 with very small amounts of TGF-β1 seen. The isoforms were more abundant in developing rather than adult retina and in central rather than peripheral retina. Studies of the distribution of TGF-β protein and mRNA using immunohistochemistry and in situ hybridisation confirmed the low levels of TGF-β1 protein and mRNA observed in QPCR and demonstrated distinct centroperipheral gradients in the photoreceptor layer for TGF-β2 and TGF-β3. Relative high amounts of TGF-β in the fovea could affect vascular patterning due to TβRI seen in astrocytes which lead the blood vessels at the foveal rim at the level of the ganglion cell plexus. TGF-β2 and TGF-β3 expression is detected before formation of the foveal avascular zone (FAZ) at fd64 (~15WG) - fd73 (~17WG) with levels peaking in the foveal region at fd105 (~25WG) by the time the FAZ forms. Conclusions: This thesis has shown that EC proliferation in the choriocapillaris does not appear to be promoted by increased metabolic activity in central retinal neurons as reduced rates of EC proliferation in the ‘foveal’ chorioretinal location were observed at all ages studied between 14 and 18.5WG. The findings suggest that mechanisms regulating proliferation and growth of the choroidal vasculature are independent of differentiation in the neural retina and are therefore different to those governing the formation of the retinal vasculature. All TGF-β isoforms are expressed in developing and adult human and macaque retina with TGF-β2 being the predominant isoform. TGF-β isoforms are more abundant in central compared to peripheral retina and in developing compared to adult retina. Centro-peripheral gradients of TGF-β2 and TGF-β3 across the photoreceptor layer and TβRI on astrocytes support the presence of TGF-β in the fovea as an antiproliferative and antiangiogenic factor by helping to define the FAZ early in development, well before 23-25 WG in humans and before fd100 in macaques
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