Dans le cadre de l'intégration « 3D », une technologie d'assemblage par report de puces sur tranche de silicium (« flip chip ») reposant sur un procédé de microinsertion a été développée ces dernières années. Cette technologie est basée principalement sur la mise en contact par thermocompression, de réseaux de (micro)inserts en Nickel ECD, avec des plots de connexions métalliques en Al(Cu). Au cours de ce travail, un scénario de formation du contact entre un unique microinsert de Nickel rugueux et un film mince d'Aluminium lisse, prenant en compte la présence d'Alumine native à l'interface de contact, est proposé pour une gamme de pressions allant du MPa au GPa. L'analyse du contact métal-oxyde-métal se base essentiellement sur la fissuration de l'oxyde natif suivie de l'extrusion du métal au travers des fissures, et nécessite d'établir au préalable les lois de comportement des matériaux mis en jeu à partir d'essais de nanoindentation instrumentée couplés à des simulations numériques. Enfin, la mesure de l'évolution de la résistance électrique de contact en fonction de la force appliquée à l'aide de dispositifs expérimentaux originaux, permet de mettre en évidence les différents mécanismes de formation du contact métallique lors du procédé de microinsertion. / In the field of « 3D » microelectronic integration, a wafer level technology using flip chip stacking and based on a microinsertion process has been developed recently. This technology is mainly based on the contact realized by thermocompression between a network of microinserts made of Nickel ECD, with connections pads in Al(Cu). In this work, a scenario describing the contact establishment between a unique rough microinsert of Nickel and a smooth thin Aluminum film taking into account the presence of native Alumina at the contact interface, is developed for a range of pressures from MPa to GPa. The analysis of the metal-oxide-metal contact is essentially based on the fracture of the native oxide followd by the metal extrusion through cracks, and requires the knowledge of the behaviour laws of materials, obtained from instrumented nanoindentation tests coupled with numerical modeling. Finally, the measure of the electrical contact resistance evolution in function of applied load, with specific pioneering experimental setup, showcases the mechanisms driving the formation of metallic contact during the microinsertion process.

Erdheim-Chester disease (ECD) represents a clonal non-Langerhans histiocytosis, which manifests under an extensive variety of clinical symptoms. This creates a challenge for the physician, who is required to recognize and diagnose the disease in the early stages. Despite this considerable challenge, in the last decade there has been a dramatic increase in ECD diagnoses, in most part due to an increasing awareness of this rare disorder. Involvement of the axial skeleton is exclusively uncommon with no official recommendations for the treatment of the bone lesions. Here, we present a case report of a young male patient with isolated lesions of the spine, ribs, and pelvis, who was successfully treated with a combination therapy of alfa-interferon and zoledronic acid.

Sensory inputs of hearing and vision during early childhood development support the achievement of language, speech and educational milestones. The early detection of sensory impairment is essential for facilitating early childhood development, socio-emotional well-being and academic success, in addition to obtaining sustainable educational development goals. The majority of children with sensory impairment live in low- and middle-income countries where services are often unavailable or inaccessible, because of the absence of systematic screening programmes for children, prohibitive equipment cost, a shortage of trained personnel and centralised service-delivery models. Therefore, research is needed to investigate whether a community-based mobile health (mHealth) supported service-delivery model for hearing and vision screening can increase access to hearing and vision services for children in resource-constrained settings. This study aimed to describe an implemented hearing and vision screening programme and evaluate its success in terms of acceptability (consent return numbers), coverage (number of eligible children screened), referral rates and quality indicators (duration of tests and number of hearing tests conducted under conditions of excessive noise levels). The study also explored the challenges faced during a community-based screening programme and the strategies developed to address these. Four non-professionals were appointed and trained as community health workers (CHWs) to conduct combined sensory screening using mHealth technology (hearScreen application, hearXGroup, South Africa and Peek Acuity application, Peek Vision, United Kingdom) on smartphones at preschools in low-income communities in Cape Town, South Africa. The consent form return rate was 82.0%, and the coverage rate was 94.4%. An average of 501 children were screened each month, at a cost of US$5.63 per child. The number of children who failed hearing and vision screening was 435 (5.4%) and 170 (2.1%), respectively. Failing of hearing tests was associated with longer test times (odds ratio [OR]: 1.022; 95% confidence interval [CI]: 1.021–1.024) and excessive background noise levels at 1 kHz (e.g. OR for left ear: 1.688; 95% CI: 1.198–2.377). Failing of visual screening tests was associated with longer test duration (OR: 1.003; 95% CI: 1.002–1.005) and younger age (OR: 0.629; 95% CI: 0.520–0.761). The study also aimed to describe and compare the performance of two screening protocols that were used in this preschool hearing screening programme to determine optimal referral criteria that is responsive to available resources. Secondary data analysis was done to compare a protocol using a single-frequency fail criterion (which 2,147 children were screened with between 1 October 2017 and 25 February 2018) with a screening protocol using a two-frequency fail criterion (which 5,782 children were screened with between 26 February 2018 and 30 November 2018). For both protocols, screening was done at a 25 dB hearing level (HL) at 1000, 2000 and 4000 Hz. Both protocols included an immediate rescreen at the frequencies that were failed. The referral rate was 8.7% (n = 186) for the one-frequency fail protocol and 4.3% (n = 250) for the two-frequency fail protocol. Compared to the one-frequency fail protocol, children screened with the two-frequency fail protocol were 52.9% less likely to fail (OR: 0.471; 95% CI: 0.385–0.575). Gender (OR: 0.807; 95% CI: 0.531–1.225) and age (OR: 0.996; 95% CI: 0.708–1.402) had no significant effect on screening outcomes. Maximum permissible ambient noise levels (MPANLs) were exceeded in 44.7% of cases in at least one ear at 1000 Hz across both protocols. There was no significant difference between the protocols for both true positive cases and false positive cases. Protocol (OR: 1.338; 95% CI: 0.854–2.098), gender (OR: 0.807; 95% CI: 0.531–1.225) and age (OR: 0.996; 95% CI: 0.708–1.402) demonstrated no significant effect on the odds of producing true positive results. Average time for conducting the screening was 72.8 s (78.66 SD) for the one-frequency fail protocol and 64.9 s (55.78 SD) for the two-frequency fail protocol. Estimating the prevalence and describing the characteristics of sensory loss in a preschool population in low-income communities are important steps to ensure adequate planning and successful implementation of community-based hearing and vision care in this context. The study therefore also investigated the prevalence and characteristics of hearing and vision loss among preschool children (4 to 7 years) in an underserved South African community after implementing mHealth-supported community-based hearing and vision services. Children who failed hearing and vision screening were seen for follow-up assessments at their preschools. Follow-up assessments were also performed with smartphones and hearing and vision testing applications (hearTest application, hearX Group, South Africa and PeekAcuity app, Peek Vision, United Kingdom). A total of 10,390 children were screened at 298 preschools over 22 months. Of the children screened, 5.6% and 4.4% of children failed hearing and vision screening, respectively. Community-based follow-up hearing tests were done at the preschools on 88.5% (514) of the children, of whom 240 children (54.2% female) presented with hearing loss. A preschool-based follow-up vision test was conducted on 400 children (88.1%). A total of 232 children (46.1% female) had a vision impairment, and a further 32 children passed the test but had obvious signs of ocular morbidity. Logistic regression analysis found that age was a significant predictor of vision loss (p < 0.001): with every 1-year increase in age, participants were 51.4% less likely to have vision loss (OR: 0.49, 95% CI: 0.39–0.60). Age was not a significant predictor for hearing loss (OR: 0.821; 95% CI: 0.667–1.011). Gender was not a significant predictor of hearing loss (OR: 0.850; 95% CI: 0.658–1.099) or vision loss (OR: 1.185; 95% CI: 0.912–1.540). The prevalence of hearing loss at a pure tone average (PTA) of 25 dB HL ranged between 2.3% (240 out of 10,390; assuming none of the non-attenders and children who were unable to be tested had hearing loss) and 3.1% (321 out of 10,390; assuming all the non-attenders and children who were unable to be tested presented with hearing loss). The prevalence of vision loss ranged between 2.2% (232 out of 10,390; assuming none of the non-attenders had vision loss) and 2.8% (286 out of 10,390; assuming all the non-attenders presented with vision loss). Findings of this research project indicate that mHealth-supported CHW-delivered hearing and vision screening in preschools provide a low-cost, efficient and accessible service that can improve the provision of affordable hearing and vision care. This service-delivery model is affordable and scalable, because the same staff, needing minimal training, and the same equipment are used to screen for both vision and hearing. Timely identification of sensory losses is essential to ensure optimal outcomes and can be facilitated through community-based hearing and vision services by trained CHWs using mHealth technology. Future studies should aim to report on outcomes and the uptake and impact of interventions on the children diagnosed with sensory impairments following identification through a decentralised screening programme. / Thesis (PhD (Audiology))--University of Pretoria, 2021. / Sonova AG / Hear the World Foundation / Speech-Language Pathology and Audiology / PhD (Audiology) / Unrestricted

BACKGROUND: Evidence supports the importance of Early Childhood Development (ECD) interventions to improve children's health, lifelong productivity, and human capital. However, ECD programs are not scaled sufficiently to reach many of the 250 million young children globally who are not meeting their developmental potential. Practical guidance is limited on how to scale ECD programs effectively. This mixed-method study explored the contextual and implementation determinants of scaling up ECD programs in Zambia, using one large-scale, community-based parenting group program (Scaling Up Early Childhood Development in Zambia (SUpErCDZ) program) as a case study. The goal was to generate recommendations for policymakers and implementers in Zambia and other LMICs. METHODS: This study was guided by the WHO/ExpandNet scale-up framework and the Intervention Scalability Assessment Tool (ISAT). A total of 30 key informant interviews were conducted with program staff, government officials, academic partners, implementing partners of other ECD programs, and donors. Qualitative transcripts were analyzed using thematic analysis according to the framework method. A budget impact analysis (BIA) was conducted using prospectively collected program cost and implementation data supplemented by online sources and interviews with program staff. The total cost of scale-up over five years using three scenarios (low, medium, and high intensity) was modeled. RESULTS: According to government officials, donors, and partners, the most common contextual factors influencing scale-up ECD programs are political commitment, availability of an overarching or multisectoral ECD policy, availability of resources, and integration of ECD programs into existing government structures. In addition, multisectoral collaboration, stakeholders’ engagement, and sociocultural factors emerged as themes essential to scale-up. From the perspective of the program staff, the key facilitators of ECD implementation were stakeholders’ engagement, sociocultural factors (cultural norms and beliefs), adaptation of the intervention to the context, integration into existing government structures, and intervention characteristics. In addition, providing incentives to Community-Based Volunteers (CBVs) emerged as critical to sustainability. The main barriers to implementation identified by the program staff were the use of culturally inappropriate activities within the ECD curriculum, lack of incentives (financial or in-kind) to caregivers and CBVs, and unforeseen contextual circumstances (COVID-19 pandemic and insecurity). The budget impact analysis showed that the total cost and budget for scaling up SUpErCDZ or a similar ECD program depends on the magnitude of the scale-up in terms of geographic breadth and depth (coverage within specific geographic areas). Based on our scale-up scenarios, the estimated cost of scaling up this program over five years ranged between US$1.74M to US$4.3M depending on the breadth (how many provinces) and depth (how many health facilities, CBVs, and caregivers) of implementation. CONCLUSION: Multiple complex and interrelated contextual and implementation factors influence the scaling up of ECD programs in Zambia. To ensure equitable access to ECD programs for children under five in Zambia, policymakers and implementers will need to consider these when planning to scale up ECD interventions in Zambia. / 2025-08-04T00:00:00Z

No description available.

This thesis investigates an alternative solution to deal with the civil structure vibration. Non-contact electromagnetic or Eddy current damping is selected as a score of vibration suppression. Electromagnetic damping relies on the interaction between a permanent magnet and conductor. An electromagnetic damper (EMD) is applied both to a laboratory footbridge structure and 6-storey model-scale aluminium moment resisting frame (AMRF). In this first study the EMD is connected in series with an electronic shunt circuit to construct an electromagnetic shunt damper (EMSD). A robust optimisation method is applied to develop the corresponding optimal design formula of the EMSD. The principle of an EMSD is to convert mechanical energy to electrical energy. Hence, the induced electromotive force (emf) is generated by electromagnetic induction. This emf induces an amount of shunt damping, which is fedback to the structure to achieve vibration suppression. It was found that when the impedance was applied, the shunt damping feature was of a similar nature to viscous dampers. In contrast, when an RLC (resistance-inductance-capacitance) circuit is connected, the shunt damping is analogous to a tuned mass damper. A second form of EMD is Eddy current damper (ECD), which relies on a geometrical arrangement of permanent magnets and conductors to produce damping forces. The vertical and horizontal orientation of the magnet, unidirectional and alternative pole projection and moving different direction of the conductor are investigated. A theoretical study involving the infinite boundary and finite boundary (the method of images current) is carried out to obtain an analytical calculation of the damping force. On the basis of this analysis, one type of ECD prototype was physically built. A performance test was carried out to determine the damping characteristics of the ECD, which agreed with the results of the numerical analysis. In addition, the ECD was applied to control the dynamics of the 6-storey AMRF. It was found that, the ECD can effectively increase system damping and have a satisfactory control effect.

Why does the implementation of policies for educational improvement often disappoint? The literature suggests that pitfalls in the formulation stage can hamper successful implementation. This research aims to develop insights into the process of policy formulation in order to establish how this may affect subsequent policy implementation using a case study of Pre-Primary Education in Bangladesh. Uniquely, I have been able to study the development of PPE policy when it was taking place since I was directly involved in the process as a professional advisor working for a donor. The first research question investigated how the pre-primary policy was formed. This had two parts in terms of i) developing understanding of the phases of policy formulation and the stakeholders involved, and ii) analysing the discourses that informed the policy. The second research question enquired into the development of the implementation strategy and its feasibility, and compared expectations with the data available on the characteristics and impact of the initial implementation. This enabled the identification of aspects of policy formulation that shape current and future implementation. Special attention was given to the development of policy that prioritised underprivileged children throughout the process, because of the extent of unequal provision and because this was a high profile goal for educational development. The analysis of policy development derived from relevant policy documents and keyinformant interviews highlighted charismatic and politicised approaches to educational reform, which lacked the involvement of beneficiaries and those tasked with implementation. This has consequences for subsequent impact and the sustainability of the new policy. The initial implementation was generally considered inadequate and uneven by the respondents. It reflected aspirational planning linked to the EFA goals, with ambitious aims to provide a "quantitative breakthrough" in access and attainment without a realistic assessment of the resources available and the capacity to mobilise them. When the implementation strategy was updated and included in the third national programme of primary education (PEDP III), a more phased and comprehensive approach to planning was introduced. However, reports on programme implementation have identified delays and difficulties in starting PEDP III, albeit improvements between year 1 and 2 have been noted. In particular, the implementation strategies identified were insufficiently detailed and different stakeholders' needs were not properly assessed. More equitable delivery to underprivileged children remains poorly articulated. Part of the reason appears to be diminished political will and inconsistent leadership. Finally, opportunities to collaborate with the NGO service providers have not been fully exploited and the implementation planning for PEDP III appeared to have relied excessively on external expertise, with implications for the ownership and continuity of the policy on pre-school. Based on these findings, suggestions are offered to the development partners, the Government and the NGOs to improve the integration of policy and implementation strategies to increase the probability of sustained improvements in Pre Primary provision.

<p>In the growing field of proteomics identification of proteins by tandem mass spectrometry (MS/MS) is performed by matching experimental mass spectra against calculated spectra of all possible peptides in a protein database. One problem with this approach is the false-positive identifications. MS-based proteomics experiments are further affected by a rather poor efficiency typical in the range of 10-15%, implicating that only a low percentage of acquired mass spectrometric data is significantly identified and assigned a peptide sequence.</p><p>In this thesis improvement in spectrum specificity is accomplished by using a combination of high-accuracy mass spectrometry and techniques that will yield complementary sequence information. Performing collision-activated dissociation (CAD) and electron capture dissociation (ECD) upon the same peptide ion will yield such complementary sequence information. Implementing this into a proteomics approach and showing the advantages of using complementary fragmentation techniques for improving peptide identification is shown. Furthermore, a novel database-independent score is introduced (S-score) based upon the maximum length of the peptide sequence tag derived from complementary use of CAD and ECD. The S-score can be used to separate poor quality spectra from good quality spectra. An-other aspect of the S-score is the development of the ‘reliable sequence tag’ which can be used to recover below threshold identifications and for a reliable backbone for de novo sequencing of peptides.</p><p>A novel proteomics-grade de novo sequencing algorithm has also been developed based upon the RST, which can retrieve peptide identification with the highest reliability (>95%). Furthermore, a novel software tool for unbiased identifications of any post-translational modifications present in a peptide sample is introduced (ModifiComb). Combining all the tools described in this thesis increases the identification specificity (>30 times), recovers false-negative identifications and increases the overall efficiency of proteomics experiements to above 40%. Currently one of the highest achieved in large-scale proteomics.</p>

There are 209 PCB congeners, 136 of which have been found in technical PCB mixtures and hence may be found in the environment as a result of either intentional or unintentional release. The identification and quantification of the congeners are difficult due to analytical bias from coeluting PCBs and other persistent organic pollutants. Among the 209 possible PCB congeners, 19 tri- and tetra-ortho chlorinated congeners exist in stable atropisomeric conformations. The racemization barrier were determined for twelve of the nineteen atropisomers and was found to be between 176-185 kJ × mol-1 and ca. 250 kJ × mol-1 for tri- and tetra-ortho PCB, respectively. Further, a buttressing effect of 6.4 kJ × mol-1 was observed for congeners with vicinal ortho-meta chlorines. Comprehensive two-dimensional gas chromatography (GC×GC) was used to analyze the atropisomers and other PCBs. A Longitudinally Modulated Cryogenic System (LMCS) was used with liquid CO2 as cryogen. The LMCS was optimized for semi-volatile organic substances, primarily PCBs. The trap temperature was shown to be an important factor for the trapping and desorption efficiency, as was the thermal mass of the column used in the modulator region. A number of column sets were tested and the separation efficiency, congener resolution and analysis time was evaluated. Good separation of non- and mono-ortho PCBs and “bulk” PCBs (in a technical PCB) was obtained within 8 min using a smectic liquid crystal column (LC50) as the first and a nonpolar column as the second dimension column. Using a second column, an efficient nonpolar (DB-XLB) column, which separates many PCB congeners, were combined with a polar (cyanopropyl) or shape selective (LC50) second dimension column. As a maximum, 181 of the 209 congeners and 126 of the 136 Aroclor PCBs were resolved. The seven frequently measured PCBs (PCBs 28, 52, 101, 118, 138, 153 and 180) and all WHO-PCBs were separated from all other Aroclor PCBs. Chiral PCBs are released into the environment as racemic mixtures. However, organisms have been shown to enantiomerically enrich many of the atropisomers, suggesting that enantioselective biotransformations occur. Non-racemic PCB enrichment has also been seen in mammalians including humans, which is of particular concern because of the potential health risk. An analytical procedure were therefore developed and used to determine the levels of atropisomeric PCBs, planar-PCBs (WHO-PCBs) and total PCBs in seals with different health status. GC×GC was used to separate the target PCBs from other PCBs and potential interferences. A chiral column (permethylated â-cyclodextrin) was used in combination with a polar or shape selective column and enantiomeric fractions (EFs) were determined for five atropisomeric PCBs, i.e. CBs 91, 95, 132, 149 and 174. Some atropisomers had EF that deviated largely from racemic. The deviation was larger in liver than blubber, indicating enantioselective metabolism. However, there was no selective passage of the studied atropisomeric PCBs across placenta and no selective blood-brain barrier. Similarly, no correlation between EFs and health status was observed, although there was a correlation between total PCBs and health status.

In the growing field of proteomics identification of proteins by tandem mass spectrometry (MS/MS) is performed by matching experimental mass spectra against calculated spectra of all possible peptides in a protein database. One problem with this approach is the false-positive identifications. MS-based proteomics experiments are further affected by a rather poor efficiency typical in the range of 10-15%, implicating that only a low percentage of acquired mass spectrometric data is significantly identified and assigned a peptide sequence. In this thesis improvement in spectrum specificity is accomplished by using a combination of high-accuracy mass spectrometry and techniques that will yield complementary sequence information. Performing collision-activated dissociation (CAD) and electron capture dissociation (ECD) upon the same peptide ion will yield such complementary sequence information. Implementing this into a proteomics approach and showing the advantages of using complementary fragmentation techniques for improving peptide identification is shown. Furthermore, a novel database-independent score is introduced (S-score) based upon the maximum length of the peptide sequence tag derived from complementary use of CAD and ECD. The S-score can be used to separate poor quality spectra from good quality spectra. An-other aspect of the S-score is the development of the ‘reliable sequence tag’ which can be used to recover below threshold identifications and for a reliable backbone for de novo sequencing of peptides. A novel proteomics-grade de novo sequencing algorithm has also been developed based upon the RST, which can retrieve peptide identification with the highest reliability (&gt;95%). Furthermore, a novel software tool for unbiased identifications of any post-translational modifications present in a peptide sample is introduced (ModifiComb). Combining all the tools described in this thesis increases the identification specificity (&gt;30 times), recovers false-negative identifications and increases the overall efficiency of proteomics experiements to above 40%. Currently one of the highest achieved in large-scale proteomics.