Energetics and stability of nanostructured amorphous carbon

Monte Carlo simulations, supplemented by ab initio calculations, shed light into the energetics and thermodynamic stability of nanostructured amorphous carbon. The interaction of the embedded nanocrystals with the host amorphous matrix is shown to determine in a large degree the stability and the relative energy differences among carbon phases. Diamonds are stable structures in matrices with sp^3 fraction over 60%. Schwarzites are stable in low-coordinated networks. Other sp^2-bonded structures are metastable.Comment: 11 pages, 7 figure

Leadership and Change Management in a Rapidly Changing Environment

Article published in the 4th Annual International Conference on Public Administration and Development Alternatives 03 - 05 July 2019, Southern Sun Hotel, OR Tambo International Airport, Johannesburg, South AfricaThe Heads of Departments (HoDs) in the South African public sector are appointed on a five-year contract and not on a permanent capacity and there is also a high turnover of HoDs. The frequent change of HoDs is further exacerbated by the rapid changes taking place in the environment, which means that change management has to be implemented fast and efficiently, any delay or disruption can have an adverse effect on the change process. The purpose of this research was to investigate the effect that the high turnover rate of HoDs in the South African public sector has on maintaining the momentum at which government programmes are being undertaken specifically focusing on the implementation of the Outcomes Approach. The Presidency in South Africa implemented the Outcomes Approach in 2010, which monitors government performance in the country. The intention of the Outcomes Approach is to enhance service delivery, therefore all government departments in the country have a role to play in the Outcome Approach. As with any new project or programme, there is the need for a rigorous change management process with committed and supportive leadership. This research study looked at how change management was implemented and sustained, for the Outcomes Approach, with the frequent change of leadership. A qualitative approach was used for this research. The findings showed that in some cases the change of HoD influenced the department in a positive manner while in other cases it had negative results. Change management was conducted, to varying extents as there was more reliance on the National Development Plan. Most change management models were developed before the onset of rapid change and frequent change of HoDs; therefore, the Triple I Change Management Model was developed for this study where there is frequent change of leadership in a rapidly changing environment

ApHMM: Accelerating Profile Hidden Markov Models for Fast and Energy-Efficient Genome Analysis

Profile hidden Markov models (pHMMs) are widely employed in various bioinformatics applications to identify similarities between biological sequences, such as DNA or protein sequences. In pHMMs, sequences are represented as graph structures. These probabilities are subsequently used to compute the similarity score between a sequence and a pHMM graph. The Baum-Welch algorithm, a prevalent and highly accurate method, utilizes these probabilities to optimize and compute similarity scores. However, the Baum-Welch algorithm is computationally intensive, and existing solutions offer either software-only or hardware-only approaches with fixed pHMM designs. We identify an urgent need for a flexible, high-performance, and energy-efficient HW/SW co-design to address the major inefficiencies in the Baum-Welch algorithm for pHMMs. We introduce ApHMM, the first flexible acceleration framework designed to significantly reduce both computational and energy overheads associated with the Baum-Welch algorithm for pHMMs. ApHMM tackles the major inefficiencies in the Baum-Welch algorithm by 1) designing flexible hardware to accommodate various pHMM designs, 2) exploiting predictable data dependency patterns through on-chip memory with memoization techniques, 3) rapidly filtering out negligible computations using a hardware-based filter, and 4) minimizing redundant computations. ApHMM achieves substantial speedups of 15.55x - 260.03x, 1.83x - 5.34x, and 27.97x when compared to CPU, GPU, and FPGA implementations of the Baum-Welch algorithm, respectively. ApHMM outperforms state-of-the-art CPU implementations in three key bioinformatics applications: 1) error correction, 2) protein family search, and 3) multiple sequence alignment, by 1.29x - 59.94x, 1.03x - 1.75x, and 1.03x - 1.95x, respectively, while improving their energy efficiency by 64.24x - 115.46x, 1.75x, 1.96x.Comment: Accepted to ACM TAC

Wastewater-integrated pathogen surveillance dashboards enable real-time, transparent, and interpretable public health risk assessment and dissemination.

Timely pathogen surveillance and reporting is essential for effective public health guidance. Web dashboards have become a key tool for communicating public health information to stakeholders, health care workers, and the broader community. Over the SARS-CoV-2 pandemic, wastewater surveillance has increasingly been incorporated into public health workflows for outbreak monitoring and response, enabling community-representative and low-cost monitoring to supplement clinical surveillance. However, the methods used for visualization and dissemination of clinical and wastewater surveillance data differ across programs, and best practices are yet to be defined. In this work, we demonstrate data workflows and dashboards used to perform wastewater-based public health surveillance in tandem with clinical data across local and national scales, leveraging custom-built, reproducible, and open-source software. Using a centralized data aggregation and analysis hub approach, we establish multiple data pipelines for data storage, wrangling, and standardized analyses, and deploy custom-built web dashboards that allow for immediate public release. We find that our approach is effective across scales, computing architectures, and dissemination strategies, and provides an adaptable model to incorporate additional pathogens and epidemiological data

The effect of prenatal balanced energy and protein supplementation on gestational weight gain: An individual participant data meta-analysis in low- and middle-income countries

Background AU Understanding: Please confirm that all heading levels are represented correctly the effects of balanced energy and protein (BEP): supplements on gestational weight gain (GWG) and how the effects differ depending on maternal characteristics and the nutritional composition of the supplements will inform the implementation of prenatal BEP interventions. Methods and findings Individual participant data from 11 randomized controlled trials of prenatal BEP supplements (N = 12,549, with 5,693 in the BEP arm and 6,856 in the comparison arm) in low- and middle-income countries were used. The primary outcomes included GWG adequacy (%) and the estimated total GWG at delivery as continuous outcomes, and severely inadequate (125% adequacy) as binary outcomes; all variables were calculated based on the Institute of Medicine recommendations. Linear and log-binomial models were used to estimate study-specific mean differences or risk ratios (RRs), respectively, with 95% confidence intervals (CIs) of the effects of prenatal BEP on the GWG outcomes. The study-specific estimates were pooled using meta-analyses. Subgroup analyses were conducted by individual characteristics. Subgroup analyses and meta-regression were conducted for study-level characteristics. Compared to the comparison group, prenatal BEP led to a 6% greater GWG percent adequacy (95% CI: 2.18, 9.56; p = 0.002), a 0.59 kg greater estimated total GWG at delivery (95% CI, 0.12, 1.05; p = 0.014), a 10% lower risk of severely inadequate GWG (RR: 0.90; 95% CI: 0.83, 0.99; p = 0.025), and a 7% lower risk of inadequate GWG (RR: 0.93; 95% CI: 0.89, 0.97; p = 0.001). The effects of prenatal BEP on GWG outcomes were stronger in studies with a targeted approach, where BEP supplements were provided to participants in the intervention arm under specific criteria such as low body mass index or low GWG, compared to studies with an untargeted approach, where BEP supplements were provided to all participants allocated to the intervention arm. Conclusions Prenatal BEP supplements are effective in increasing GWG and reducing the risk of inadequate weight gain during pregnancy. BEP supplementation targeted toward pregnant women with undernutrition may be a promising approach to delivering the supplements

Child wasting and concurrent stunting in low- and middle-income countries

Sustainable Development Goal 2.2—to end malnutrition by 2030—includes the elimination of child wasting, defined as a weight-for-length z-score that is more than two standard deviations below the median of the World Health Organization standards for child growth 1. Prevailing methods to measure wasting rely on cross-sectional surveys that cannot measure onset, recovery and persistence—key features that inform preventive interventions and estimates of disease burden. Here we analyse 21 longitudinal cohorts and show that wasting is a highly dynamic process of onset and recovery, with incidence peaking between birth and 3 months. Many more children experience an episode of wasting at some point during their first 24 months than prevalent cases at a single point in time suggest. For example, at the age of 24 months, 5.6% of children were wasted, but by the same age (24 months), 29.2% of children had experienced at least one wasting episode and 10.0% had experienced two or more episodes. Children who were wasted before the age of 6 months had a faster recovery and shorter episodes than did children who were wasted at older ages; however, early wasting increased the risk of later growth faltering, including concurrent wasting and stunting (low length-for-age z-score), and thus increased the risk of mortality. In diverse populations with high seasonal rainfall, the population average weight-for-length z-score varied substantially (more than 0.5 z in some cohorts), with the lowest mean z-scores occurring during the rainiest months; this indicates that seasonally targeted interventions could be considered. Our results show the importance of establishing interventions to prevent wasting from birth to the age of 6 months, probably through improved maternal nutrition, to complement current programmes that focus on children aged 6–59 months

Early-childhood linear growth faltering in low- and middle-income countries

Globally, 149 million children under 5 years of age are estimated to be stunted (length more than 2 standard deviations below international growth standards) 1,2. Stunting, a form of linear growth faltering, increases the risk of illness, impaired cognitive development and mortality. Global stunting estimates rely on cross-sectional surveys, which cannot provide direct information about the timing of onset or persistence of growth faltering—a key consideration for defining critical windows to deliver preventive interventions. Here we completed a pooled analysis of longitudinal studies in low- and middle-income countries (n = 32 cohorts, 52,640 children, ages 0–24 months), allowing us to identify the typical age of onset of linear growth faltering and to investigate recurrent faltering in early life. The highest incidence of stunting onset occurred from birth to the age of 3 months, with substantially higher stunting at birth in South Asia. From 0 to 15 months, stunting reversal was rare; children who reversed their stunting status frequently relapsed, and relapse rates were substantially higher among children born stunted. Early onset and low reversal rates suggest that improving children’s linear growth will require life course interventions for women of childbearing age and a greater emphasis on interventions for children under 6 months of age

Author Correction: Earlychildhood linear growth faltering in low- and middle-income countries

Correction to: Naturehttps://doi.org/10.1038/s41586-023-06418-5 Published online 13 September 2023 The code that we used to fit meta-analyses for the proportion of children stunted by age in Fig. 3a and Extended Data Figs. 8–10 incorrectly used the total number of children in the denominator for incidence, which incorrectly included children no longer at risk of stunting (i.e., children who had become stunted at the previous age). In the “Onset of stunting in early life” section, in the text now reading “The percentage that experienced incident stunting onset between birth and 3 months ranged from 7% to 57% in each cohort and was 18% overall”, the percentages previously read “6%”, “47%” and “16%.” We also made analogous corrections in the Supplementary information to figures of age-stratified stunting incidence. Following this correction, age-stratified stunting incidence levels were higher after birth, but trends remained similar overall. We revised the links in the Code availability section for the replication code to include these corrections. Additionally, we mislabeled the y axes of Fig. 4b and Extended Data Fig. 12 and their corresponding captions as “Incidence proportion” instead of “Proportion”. We have also corrected a typographical error in cited figures in the Methods “Linear growth velocity” section, and now cite Fig. 6 and Extended Data Fig. 14 in place of Fig. 5 and Extended Data Fig. 10. Additionally, the Reporting summary did not include an email address to contact for data requests, which is now updated. These corrections do not change the inferences we drew from the study. For comparison, original and revised figures are available in the Supplementary information. The updates appear in the HTML and PDF versions of the article. Supplementary information is available in the online version of this amendment