| 61. |
- Özdemir, Metin, 1977-
(författare)
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How much do we know about the long-term effectiveness of parenting programs? Advances, shortcomings, and future directions
- 2015
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Ingår i: Journal of Children's Services. - Bingley, United Kingdom : Emerald Group Publishing Limited. - 1746-6660 .- 2042-8677. ; 10:2, s. 120-132
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Parenting programmes are seen as feasible and cost-effective in preventing early behavioural problems in children and adolescents. A number of studies have concluded that such programmes are effective in reducing child problem behaviours and improving the skills and well-being of parents. Nevertheless, less is known about long-term programme effects.Design/methodology/approach: A non meta-analytic discussion.Findings: Long-term evaluations of parenting programmes suffer from a number of methodological weaknesses resulting in an inability to make robust causal inferences about child and parent outcomes in the longer term. The current evidence is favorable but is likely to be biased by methodological weaknesses. There is a need for more studies of greater methodological strength to obtain conclusive evidence that would guide empirical research, practice and policy.Originality/value: The paper discusses weaknesses in long-term evaluations of parenting programmes and highlights concrete future directions toward improving the quality of study design, evaluation and data analysis.
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| 62. |
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| 63. |
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| 64. |
- Özel, Sultan S., et al.
(författare)
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A facile synthesis of Ag2MnSnS4 nanorods through colloidal method
- 2022
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Ingår i: Turkish journal of chemistry. - : The Scientific and Technological Research Council of Türkiye (TÜBİTAK). - 1300-0527 .- 1303-6130. ; 46:4, s. 1291-1296
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Tidskriftsartikel (refereegranskat)abstract
- The production methods of semiconductor nanomaterials with new shapes and different compositions form the basis for the creation of high-performance structures in numerous applications. Kesterite structured materials are among these inorganic semiconductors and are suggested to be promising energy materials for the future. In this study, quaternary Ag2MnSnS4 nanocrystalline rods have been successfully synthesized for the first time by the colloidal hot-injection synthesis route and well-organized rod-like nanocrystals (NCs) with lengths ranging from 200 to 350 nm and widths from 10 to 30 nm were obtained. For this structure, the Ag2MnSnS4 exhibits a semiconductor property with a band-gap of approximately 1.3 eV. The optical properties and band-gap values were determined by UV-Vis absorption spectrum and using Tauc Equation. It has been observed that the Ag2MnSnS4 structure acquired by the proposed colloidal synthesis method can be an alternative to the commonly used materials based on Cd and Pb.
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| 65. |
- Özkahraman, Özer, 1992-, et al.
(författare)
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Combining Control Barrier Functions and Behavior Trees for Multi-Agent Underwater Coverage Missions
- 2020
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Ingår i: Proceedings of 59th Conference on Decision and Control, 2020.
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Konferensbidrag (refereegranskat)abstract
- Robot missions typically involve a number of desired objectives, such as avoiding collisions, staying connected to other robots, gathering information using sensors and returning to the charging station before the battery runs out.Some of these objectives need to be taken into account at the same time, such as avoiding collisions and staying connected, while others are focused upon during different parts of the executions, such as returning to the charging station and connectivity maintenance.In this paper, we show how Control Barrier Functions(CBFs) and Behavior Trees(BTs) can be combined in a principled manner to achieve both types of task compositions, with performance guarantees in terms of mission completion. We illustrate our method with a simulated underwater coverage mission.
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| 66. |
- Özkahraman, Özer, 1992-, et al.
(författare)
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Data-Driven Damage Detection and Control Adaptation for an Autonomous Underwater Vehicle
- 2022
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Ingår i: 61st IEEE Conference on Decision and Control (CDC), 2022.
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Konferensbidrag (refereegranskat)abstract
- Underwater robotic exploration missions typically involve traveling long distances without any human contact.The robots that go on such missions risk getting damaged by the unknown environment, accruing great costs and missed opportunities.Thus it is important for the robot to be able to accommodate unknown changes to its dynamics as much as possible and attempt to finish the given mission, or at the very least move itself to a retrievable position.In this paper, we show how we can detect physical changes to the robot reliably (79\% on real robot data) and then incorporate these changes through adapting the model to the data followed by automated control redesign. We adopt a piecewise-affine (PWA) modelling of the dynamics that is well suited for low data regime learning of the dynamics and provides a structure for computationally efficient control synthesis.We demonstrate the effectiveness of the proposed method on a combination of real robot data and simulated scenarios.
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| 67. |
- Özkaya Sahin, Gülsen, et al.
(författare)
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Frequent intratype neutralization by plasma immunoglobulin A identified in HIV-2 infection.
- 2013
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Ingår i: AIDS Research and Human Retroviruses. - 1931-8405. ; 29:3, s. 470-478
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Tidskriftsartikel (refereegranskat)abstract
- Human immunodeficiency virus type 2 (HIV-2) is less transmissible and less pathogenic compared to HIV-1 and, when matched for CD4+ T cell count, the plasma viral load in HIV-2 infected individuals is approximately one log lower than in HIV-1 infected individuals. The explanation for these observations is elusive, but differences in virus controlling immunity generated in the two infections may be contributing factors. In the present study, we investigated neutralization by immunoglobulin A (IgA), in parallel with IgG, purified from plasma of HIV-1, HIV-2 and HIV-1/HIV-2 dually (HIV-D)-infected individuals. Neutralization was analyzed against HIV-1 and HIV-2 isolates using a plaque reduction assay. In HIV-2 infection, intratype-specific neutralization by IgA was frequently detected, although at a lesser magnitude then the corresponding IgG neutralizing titers. In contrast, neutralization by IgA could rarely be demonstrated in HIV-1 infection despite similar plasma IgA levels in both infections. In addition, IgA and IgG of HIV-D plasma neutralized the HIV-2 isolate more potently than the HIV-1 isolate, suggesting that the difference between neutralizing activity of plasma IgA and IgG depends on the virus itself. Taken together, these findings suggest that both IgA and IgG adds to the potent intratype neutralizing activity detected in HIV-2 plasma, which may contribute to virus control in HIV-2 infection.
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| 68. |
- Özkaya Sahin, Gülsen, et al.
(författare)
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Generation of neutralizing antibodies and divergence of SIVmac239 in cynomolgus macaques following short-term early antiretroviral therapy.
- 2010
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Ingår i: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 6:9
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Tidskriftsartikel (refereegranskat)abstract
- Neutralizing antibodies (NAb) able to react to heterologous viruses are generated during natural HIV-1 infection in some individuals. Further knowledge is required in order to understand the factors contributing to induction of cross-reactive NAb responses. Here a well-established model of experimental pathogenic infection in cynomolgus macaques, which reproduces long-lasting HIV-1 infection, was used to study the NAb response as well as the viral evolution of the highly neutralization-resistant SIVmac239. Twelve animals were infected intravenously with SIVmac239. Antiretroviral therapy (ART) was initiated ten days post-inoculation and administered daily for four months. Viral load, CD4(+) T-cell counts, total IgG levels, and breadth as well as strength of NAb in plasma were compared simultaneously over 14 months. In addition, envs from plasma samples were sequenced at three time points in all animals in order to assess viral evolution. We report here that seven of the 12 animals controlled viremia to below 10(4) copies/ml of plasma after discontinuation of ART and that this control was associated with a low level of evolutionary divergence. Macaques that controlled viral load developed broader NAb responses early on. Furthermore, escape mutations, such as V67M and R751G, were identified in virus sequenced from all animals with uncontrolled viremia. Bayesian estimation of ancestral population genetic diversity (PGD) showed an increase in this value in non-controlling or transient-controlling animals during the first 5.5 months of infection, in contrast to virus-controlling animals. Similarly, non- or transient controllers displayed more positively-selected amino-acid substitutions. An early increase in PGD, resulting in the generation of positively-selected amino-acid substitutions, greater divergence and relative high viral load after ART withdrawal, may have contributed to the generation of potent NAb in several animals after SIVmac239 infection. However, early broad NAb responses correlated with relatively preserved CD4(+) T-cell numbers, low viral load and limited viral divergence.
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| 69. |
- Özkaya Sahin, Gülsen
(författare)
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Studies on Potency and breadth of HIV-1, HIV-2 and SIV neutralizing antibody responses
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Even though the relative contribution of neutralizing antibodies (Nab) to prevent progression to AIDS during HIV-1 infection is still unclear, the induction of broadly NAb directed against HIV-1 through vaccination is considered to represent an important goal for the development of HIV-1 vaccines. Factors contributing to the induction of NAb may include the strength and duration of antigenic stimulation, the preservation of CD4+ T and B cells, the conformation of the HIV-1 envelope glycoprotein complex (Env), and the evolution of Env during infection. To understand these relationships, the experimental model of pathogenic SIV infection in cynomolgus macaques and comparison of HIV-1 and HIV-2 infections in humans were used in this thesis. In the macaque model we studied in parallel the appearance of NAb and evolution of Env. For the preservation of SIV-specific cellular immune responses, early anti-retroviral treatment was provided. The main finding from this study was that the macaques that controlled viral load after treatment discontinuation displayed limited virus population genetic diversity and divergence, and had an early broad NAb response. On the other hand, the macaques with no or transient control of viremia showed greater virus diversity and divergence, and potent NAb response during the early period of infection. We propose that the early phase of viral evolution and the antigenic stimulation contributes to the development of NAb and control of viremia. In humans, HIV-2 is known to be less transmissible and less pathogenic than HIV-1. Therefore, valuable insight can be gained into HIV immunopathogenesis from studies of HIV-2 cohorts with their high proportion of long-term non-progressors. In order to analyze differences in NAb in these infections, we compared, side by side, the breadth and potency of neutralizing activity (NAc) in plasma of HIV-1, HIV-2, and dually HIV-1/2 (HIV-D) infected individuals from Guinea-Bissau against HIV-1 and HIV-2 virus panels. The striking finding was that NAc in HIV-2 plasma against HIV-2 isolates was broader and more potent than NAc in HIV-1 plasma against HIV-1 isolates. Moreover, HIV-D positive individuals had broader and more potent NAc against HIV-2 isolates than HIV-1 isolates, indicating distinct immunogenicity and/or antigenicity of HIV-2 compared to HIV-1. We next analyzed the relative role of IgG and IgA for NAc in HIV-1, HIV-2 and HIV-D plasma. Similarly to the plasma NAc, IgG neutralizing antibodies were found to be more potent in HIV-2 plasma against HIV-2 compared to IgG from HIV-1 plasma against HIV-1. Interestingly, while HIV-2 neutralizing IgA was frequently detected in plasma of HIV-2 infected individuals, HIV-1 neutralizing IgA could rarely be demonstrated in HIV-1 plasma. To study humoral immunity in HIV-1 and HIV-2 infections further, we investigated the role of complement (C’) in antibody-dependent complement-mediated inactivation. Here results showed that the C’ effect on antiviral activity against HIV-2 was more pronounced in HIV-2 plasma than the C’ effect on HIV-1 plasma against HIV-1. Analysis of HIV-D plasma corroborated that the antibody-dependent complement-mediated inactivation was more efficient against HIV-2. This finding suggests that antibody binding to HIV-2 Env facilitates efficient use of C’. In summary, this thesis may provide insights into the nature of broad and potent neutralizing humoral immune responses.
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| 70. |
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