Filtered Iterative Denoising for Linear Inverse Problems

Iterative denoising algorithms (IDAs) have been tremendously successful in a range of linear inverse problems arising in signal and image processing. The classic instance of this is the famous Iterative Soft-Thresholding Algorithm (ISTA), based on soft-thresholding of wavelet coefficients. More modern approaches to IDAs replace soft-thresholding with a black-box denoiser, such as BM3D or a learned deep neural network denoiser. These are often referred to as ``plug-and-play" (PnP) methods because, in principle, an off-the-shelf denoiser can be used for a variety of different inverse problems. The problem with PnP methods is that they may not provide the best solutions to a specific linear inverse problem; better solutions can often be obtained by a denoiser that is customized to the problem domain. A problem-specific denoiser, however, requires expensive re-engineering or re-learning which eliminates the simplicity and ease that makes PnP methods attractive in the first place. This paper proposes a new IDA that allows one to use a general, black-box denoiser more effectively via a simple linear filtering modification to the usual gradient update steps that accounts for the specific linear inverse problem. The proposed Filtered IDA (FIDA) is mathematically derived from the classical ISTA and wavelet denoising viewpoint. We show experimentally that FIDA can produce superior results compared to existing IDA methods with BM3D

The influence of flush feeding with different nitrogen sources on ovulation and conception rates in Dohne-Merino ewes

The aim of the present study was to determine if there is a difference in ovulation- and conception rates, in semiintensively managed Dohne-Merino ewes, flush fed with diets containing different nitrogen sources. Four different nitrogen sources were chosen due to the difference in dietary amino acid composition and cost. In order for a sheep farming enterprise to maximize profitability it is essential to optimize ovulation- and conception rates and to minimize lamb losses in order to increase weaning percentage and therefore profitability. However the cost of dietary supplementation is high and may increase production costs and minimize profitability. One hundred and fourty four (144) Dohne-Merino ewes (age between 14 to 85 months) were included in two dietary supplementation trials (autumn and summer) at the experimental farm of the University of Pretoria in Hatfield. The ewes were divided equally into two trial groups (n=72), with the first trial done in season 1 (started in May 2001, typical breeding season) and the second trial done in season 2 (started in November 2001, out of season; 2nd breeding season). During the day the ewes had ad-libitum access to graze on Festuca arundinaceace (Tall Fescue). In both trials the ewes (n=72) were randomly allocated into four dietary supplementation groups, each group receiving a dietary supplement with a different combination of nitrogen sources. The four dietary supplements were formulated on an iso-nitrogen basis, to eliminate the effect of protein level, and to emphasize the possible effect of protein quality (amino acid composition) on ovulation, conception and lambing rates. In both trials the total amount of crude protein intake per ewe was calculated at 256.40g/day, while the total daily allowance of digestible crude protein was calculated at 190g per ewe. The 256.40g crude protein intake per ewe per day is 2 times more than the threshold level of 125g per ewe per day. A minimum daily crude protein intake of 125g is needed for effective rumen functioning, and this together with the interconvertin of energy by the rumen indicates the complex nature of relating dietary differences to physiological responses. These values were kept the same for both the trials in season 1 and 2. The bulk of the 256.40g crude protein per day was obtained from grazing on the Festuca arundinaceace pasture. In season 1 the dietary supplement had to provide 40.00g of crude protein per day in order to get to a daily crude protein intake of 256.40g, while in season 2 the provision from the dietary supplement was calculated to be 37.45g of crude protein. The difference in the crude protein level, obtained from grazing of the Festuca arundinaceace between season 1 and 2 was due to pasture quality differences. The nitrogen sources used in the trials were urea, sunflower oilcake meal, cottonseed oilcake meal and a mixture of cottonseed oilcake meal and fishmeal. These dietary supplements were fed for a period of 9 days before mating; the weight of each ewe was recorded before the onset of the trial and again on the second day after mating to establish any live weight changes. Synchronization of the ewes was done with Chrono-gest grey sponges (40mg Fluorogestone acetate) from day one and was repeated from day 23. On day 12 each ewe were injected with 1.0ml prostaglandin F2α (Prosolvin,each milliliter containing 7.5mg Luprostiol). On day fourteen the sponges were removed and two days later all the ewes were checked for cyclic activity with the aid of six vasectomized rams. The six vasectomized rams were introduced to the whole laparoscopy group of 12 ewes, and every ewe that stood twice for mating were identified as cyclic. This practice continued for a period of 30 minutes in the morning and repeated for another 30 minutes in the afternoon up to day 18. The second round of sponges were inserted on day 23 and removed on day 37. Ewes were mated by means of hand mating with two different rams from day 39 to 42. A laparoscopy technique was used on day 45 of the trial to count the number of ovulation points (corpora lutea) on each ovarium of each ewe. The number of fetuses of each ewe was counted on day 90 after mating by means of ultrasound scanning and at birth the number of lambs born was also recorded. In both these trials dietary supplementation had no significant effect on ovulation, conception and lambing rates. However, looking at the Odds Ratio Analysis for the 144 ewes over the two breeding seasons, the different dietary supplements had a significant influence on the number of ovulation points (p<0.05). Compared to urea (dietary supplement 1), the fishmeal cottonseed oil cake mixture (dietary supplement 4) yielded the best results (1.306), followed by the cottonseed oil cake meal (dietary supplement 3) (1.298), and sunflower oil cake meal (dietary supplement 2) (1.050). The same Odds Ratio Analysis showed that the different dietary supplements had a significant effect on the number of lambs born (p<0.01). Compared to urea (dietary supplement 1), the fishmeal cottonseed oil cake mixture (dietary supplement 4) yielded better results (1.086), followed by urea (dietary supplement 1) (1.000), and sunflower oil cake meal (dietary supplement 2) (0.801) and lastly cottonseed oil cake meal (dietary supplement 3) (0.784). Breeding season (p<0.05) had a significant effect on the number of ovulation points but no difference was observed in terms of the number of lambs born. Age (p<0.01) had a significant effect on the number of ovulation points, the number of fetuses counted as well as the number of lambs born. Change in live weight (p<0.05) had a significant effect on the number of ovulation points per ewe but as with breeding season it had no significant effect on the number of lambs born. Birth status of a ewe (p<0.05), had a significant effect on the number of fetuses and the number of lambs born. The data of both the trials in season 1 and 2 suggests that under the conditions of the study with the odds ratio analyses that the four different dietary supplements had a significantly different effect compared to dietary supplement one on the number of ovulation points and the number of lambs born. However, factors like breeding season, age, change in live weight and birth status of the ewe also had a significant effect on ovulation and conception rates in Dohne-Merino ewes.Dissertation (MSc(Agric))--University of Pretoria, 2011.Animal and Wildlife Sciencesunrestricte

Saliva-based linezolid monitoring on a mobile UV spectrophotometer

Background: In TB, therapeutic drug monitoring (TDM) is recommended for linezolid; however, implementation is challenging in endemic settings. Non-invasive saliva sampling using a mobile assay would increase the feasibility of TDM. Objectives: To validate a linezolid saliva assay using a mobile UV spectrophotometer. Methods: The saliva assay was developed using NanoPhotometer NP80 (R) and linezolid concentrations were quantified using second-order derivative spectroscopy. Sample preparation involved liquid-liquid extraction of saliva, using saturated sodium chloride and ethyl acetate at 1:1:3 (v/v/v). The assay was validated for accuracy, precision, selectivity, specificity, carry-over, matrix effect, stability and filters. Acceptance criteria were bias and coefficient of variation (CV) Results: Linezolid concentrations correlated with the amplitude between 250 and 270 nm on the second-order derivative spectra. The linezolid calibration curve was Linear over the range of 3.0 to 25 mg/L (R-2 = 0.99) and the LLOQ was 3.0 mg/L. Accuracy and precision were demonstrated with bias of -7.5% to 2.7% and CV Conclusions: We validated a UV spectrophotometric assay using non-invasive saliva sampling for linezolid. The next step is to demonstrate clinical feasibility and value to facilitate programmatic implementation of TDM

Treatment Outcomes of Childhood Tuberculous Meningitis in a Real-World Retrospective Cohort, Bandung, Indonesia

We retrospectively evaluated clinical features and outcomes in children treated for tuberculous meningitis (TBM) at Hasan Sadikin Hospital, Bandung, Indonesia, during 2011–2020. Among 283 patients, 153 (54.1%) were 38°C, stage III TBM, and baseline motor deficit. Despite treatment, childhood TBM in Indonesia causes substantial neurologic sequelae and death, highlighting the importance of improved early diagnosis, better tuberculosis prevention, and optimized TBM management strategies

Corrigendum: ’n Navorsingstrategie vir missionale transformasie

No abstract availabl

’n Navorsingstrategie vir missionale transformasie

Research strategy for missional transformation. In this study, an innovative research process was developed to support a missional ecclesiology. The research strategy was designed as a practice-oriented research process in service of faith communities as ‘problem owners’ of the research. The goal is to inform and serve the process of missional transformation. The approach taken was defined as a process of discernment to participate in the missio Dei, appreciating the work of the Holy Spirit and the reciprocal relation between confession and praxis. Scripture and tradition are constitutive elements of the language house that forms the congregational life and imagination. The innovate process comprises three cycles moving through four quadrants in the deployment of a missional strategy, the four quadrants being: guidance, research, design and training. This was developed along 12 movements: (1) articulate the pain, (2) clarify the question, (3) develop the prototype, (4) testing, (5) practice capacities, (6) observe patterns, (7) build a model, (8) implementation, (9) accepting into the culture, (10) describe breakthroughs, (11) support the learning community, and (12) institutional alignment. Intradisciplinary and/or interdisciplinary implications: The research includes the following disciplines: Missiology, Missionary Ecclesiology and Practical Theology. It has wide-ranging implications, as it presents an innovative and comprehensive research process that can significantly influence research on missional transformation

Management of critical-sized bone defects in the treatment of fracture-related infection: a systematic review and pooled analysis

Purpose: This systematic review determined the reported treatment strategies, their individual success rates, and other outcome parameters in the management of critical-sized bone defects in fracture-related infection (FRI) patients between 1990 and 2018. Methods: A systematic literature search on treatment and outcome of critical-sized bone defects in FRI was performed. Treatment strategies identified were, autologous cancellous grafts, autologous cancellous grafts combined with local antibiotics, the induced membrane technique, vascularized grafts, Ilizarov bone transport, and bone transport combined with local antibiotics. Outcomes were bone healing and infection eradication after primary surgical protocol and recurrence of FRI and amputations at the end of study period. Results: Fifty studies were included, describing 1530 patients, the tibia was affected in 82%. Mean age was 40 years (range 6–80), with predominantly male subjects (79%). Mean duration of infection was 17 months (range 1–624) and mean follow-up 51 months (range 6–126). After initial protocolized treatment, FRI was cured in 83% (95% CI 79–87) of all cases, increasing to 94% (95% CI 92–96) at the end of each individual study. Recurrence of infection was seen in 8% (95% CI 6–11) and amputation in 3% (95% CI 2–3). Final outcomes overlapped across treatment strategies. Conclusion: Results should be interpreted with caution due to the retrospective and observational design of most studies, the lack of clear classification systems, incomplete data reports, potential underreporting of adverse outcomes, and heterogeneity in patient series. A consensus on classification, treatment protocols, and outcome is needed to improve reliability of future studies