Supporting development and management of smart office applications: a DYAMAND case study

To realize the Internet of Things (IoT) vision, tools are needed to ease the development and deployment of practical applications. Several standard bodies, companies, and ad-hoc consortia are proposing their own solution for inter-device communication. In this context, DYnamic, Adaptive MAnagement of Networks and Devices (DYAMAND) was presented in a previous publication to solve the interoperability issues introduced by the multitude of available technologies. In this paper a DYAMAND case study is presented: in cooperation with a large company, a monitoring application was developed for flexible office spaces in order to reliably reorganize an office environment and give real-time feedback on the usage of meeting rooms. Three wireless sensor technologies were investigated to be used in the pilot. The solution was deployed in a "friendly user" setting at a research institute (iMinds) prior to deployment at the large company's premises. Based on the findings of both installations, requirements for an application platform supporting development and management of smart (office) applications were listed. DYAMAND was used as the basis of the implementation. Although the local management of networked devices as provided by DYAMAND enables easier development of intelligent applications, a number of remote services discussed in this paper are needed to enable reliable and up-to-date support (of new technologies)

Twisting of mummified remains around the umbilical cord as a potential risk of delayed twin reduction in the mare

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Afterword: Could a Merger Lead to Both a Monopoly and a Lower Price?

This article demonstrates that significant net efficiencies from a merger could cause prices to decrease, even if the merger results in a monopoly. The article also shows that a price focus would require substantially more efficiencies to justify an otherwise anticompetitive merger than would an efficiency focus (in other words, it re-does the Williamsonian merger tradeoff, using price to consumers instead of net efficiencies as its focus). We demonstrate this by calculating how large the necessary efficiency gains would have to be to prevent price increases under different market conditions

Modelling the effectiveness of grass buffer strips in managing muddy floods under a changing climate

Muddy floods occur when rainfall generates runoff on agricultural land, detaching and transporting sediment into the surrounding natural and built environment. In the Belgian Loess Belt, muddy floods occur regularly and lead to considerable economic costs associated with damage to property and infrastructure. Mitigation measures designed to manage the problem have been tested in a pilot area within Flanders and were found to be cost-effective within three years. This study assesses whether these mitigation measures will remain effective under a changing climate. To test this, the Water Erosion Prediction Project (WEPP) model was used to examine muddy flooding diagnostics (precipitation, runoff, soil loss and sediment yield) for a case study hillslope in Flanders where grass buffer strips are currently used as a mitigation measure. The model was run for present day conditions and then under 33 future site-specific climate scenarios. These future scenarios were generated from three earth system models driven by four representative concentration pathways and downscaled using quantile mapping and the weather generator CLIGEN. Results reveal that under the majority of future scenarios, muddy flooding diagnostics are projected to increase, mostly as a consequence of large scale precipitation events rather than mean changes. The magnitude of muddy flood events for a given return period is also generally projected to increase. These findings indicate that present day mitigation measures may have a reduced capacity to manage muddy flooding given the changes imposed by a warming climate with an enhanced hydrological cycle. Revisions to the design of existing mitigation measures within existing policy frameworks are considered the most effective way to account for the impacts of climate change in future mitigation planni

Load-based generic polca: performance assessement using simulation

POLCA (i.e. Paired-cell Overlapping Loops of Cards with Authorization) is a card-based decision support system for production control, developed to support the adoption of Quick Response Manufacturing. Two variants of POLCA have been proposed in the literature to improve POLCA performance: Load Based POLCA and Generic POLCA. In this paper, we combine these two variants into a single production control system and analyse its performance for different backlog-sequencing rules. The results of a simulation study carried out for a make-to-order flow shop, support the strategy of combining these two POLCA variants and show that capacity-slack backlog sequencing based on corrected aggregate load have the potential for improving performance.info:eu-repo/semantics/publishedVersio

Lever Insertion as a Salient Stimulus Promoting Insensitivity to Outcome Devaluation

Flexible and efficient decision-making in complex environments can be achieved through constant interactions between the goal-directed and habitual systems. While goal-directed behavior is considered dependent upon Response-Outcome (R-O) associations, habits instead rely on Stimulus-Response (S-R) associations. However, the stimuli that support the S-R association underlying habitual responding in typical instrumental procedures are poorly defined. To resolve this issue, we designed a discrete-trials procedure, in which rats must wait for lever insertion and complete a sequence of five lever presses to obtain a reward (20% sucrose or grain-based pellets). Lever insertion thus constituted an audio-visual stimulus signaling the opportunity for reward. Using sensory-specific satiety-induced devaluation, we found that rats trained with grain-based pellets remained sensitive to outcome devaluation over the course of training with this procedure whereas rats trained with a solution of 20% sucrose rapidly developed habit, and that insensitivity to outcome devaluation in rats trained with sucrose did not result from a bias in general satiety. Importantly, although rats trained with pellets were sensitive to satiety-induced devaluation, their performance was not affected by degradation of instrumental contingency and devaluation by conditioned taste aversion (CTA), suggesting that these rats may also have developed habitual responding. To test whether the discrete-trials procedure biases subjects towards habitual responding, we compared discrete-trials to free-running instrumental responding, and found that rats trained with sucrose in a fixed-ratio 5 (FR5) procedure with continuous presentation of the lever were goal-directed. Together, these results demonstrate that discrete presentations of a stimulus predictive of reward availability promoted the formation of S-R habit in rats trained with liquid sucrose. Further research is necessary to explain inconsistencies in sensitivity to outcome devaluation when rats are trained with grain-based pellets

Climatic and Biogeochemical Effects of a Galactic Gamma-Ray Burst

It is likely that one or more gamma-ray bursts within our galaxy have strongly irradiated the Earth in the last Gy. This produces significant atmospheric ionization and dissociation, resulting in ozone depletion and DNA-damaging ultraviolet solar flux reaching the surface for up to a decade. Here we show the first detailed computation of two other significant effects. Visible opacity of NO2 is sufficient to reduce solar energy at the surface up to a few percent, with the greatest effect at the poles, which may be sufficient to initiate glaciation. Rainout of dilute nitric acid is could have been important for a burst nearer than our conservative nearest burst. These results support the hypothesis that the characteristics of the late Ordovician mass extinction are consistent with GRB initiation.Comment: 12 pages, 2 figures, in press at Geophysical Research Letters. Minor revisions, including details on falsifying the hypothesi

the interplay of two wicked problems

Funding Information: This work was funded by VLIR-UOS, grant numbers TZ2019SIN263 and TZ2020JOI032A101. Publisher Copyright: ©Concern is justified observing the link between the AIDS and COVID-19 pandemics. COVID-19 outcomes are significantly worse in many people living with HIV (PLHIV), even when vaccinated, because of their impaired immune system. Moreover, CD4 T-cells are affected by both HIV and SARS-CoV-2.1-3 SARS-CoV-2 variants can evolve in immunosuppressed patients due to prolonged viral replication in the context of an inadequate immune response.4 Accelerated intrahost evolution of SARS-CoV-2 was reported in a South African HIV patient with antiretroviral therapy (ART) failure.5 6 With 25 million HIV patients in sub-Saharan Africa (SSA) of whom an estimated 8 million are not virologically suppressed, this potentially creates a reservoir for future variants. Such variants, arising in PLHIV anywhere in the world, can spread to other continents, as has been reported for variants of concern (VoCs) (Beta, Omicron) and variants of interest (B.1.6.20, B.1.640.2) that arose in Africa.7-9 Conversely, the COVID-19 pandemic impacts HIV treatment programmes, due to supply chain issues, overburdening of healthcare systems, limiting access to testing, treatment and prevention programmes and further increasing inequalities.10 Modelled COVID-19 disruptions of HIV programmes in SSA included decreased functionality of HIV prevention programmes, HIV testing and treatment, healthcare services such as viral load testing, adherence counselling, drug regimen switches and ART interruptions, which may lead to selection of drug-resistant HIV.11 A 6-month interruption affecting 50% of the population would lead to a median number of excess deaths of 296 000, during 1 year. Scientists advocate for the AIDS and COVID-19 pandemics in Africa to be addressed simultaneously, by increasing African access to COVID-19 vaccines, prioritising research on the interaction between HIV care and COVID-19, maintaining high-quality HIV services and integrating health services for both viruses.7 Both the COVID-19 and the AIDS pandemic, more specifically the issue of HIV drug resistance (HIVDR), have previously been described as wicked problems which are best studied as complex adaptive systems (CASs).12-15Wicked problems consist of diverse interconnected factors and require complexity-informed and locally adapted solutions rather than one solution that fits all. We recently designed a qualitative model of all known factors influencing HIVDR in SSA and analysed its complexity.13 Our detailed systems map featured three main feedback loops driving HIVDR, representing (1) the alternation between adherence and non-adherence, (2) the impact of an overburdened healthcare system and (3) the importance of sustaining global efforts of tackling HIVDR even when new antiretroviral drugs with high genetic barriers become available. These HIV-related feedback loops are interconnected with COVID-19 pandemic impact (in yellow, figure 1). The loop starts from PLHIV with an unsuppressed viral load, which weakens the immune system and may in turn slow down immune clearance of SARS-CoV-2, allowing prolonged replication and mutation of the virus in the context of an inadequate immune response. Prolonged viral clearance facilitates the selection of immune escape SARS-CoV-2 variants. Variants may emerge that have a selective advantage and therefore may spread through populations due to increased transmissibility (with possibly increased virulence), thereby creating an additional burden on the healthcare system, putting the overall healthcare system and the HIV care at risk. These stressors on the healthcare system lead to a higher risk of unsuppressed viral load in PLHIV, increasing the risk of HIVDR. Figure 1 shows the need to address both wicked problems simultaneously and to do so in a complexity-informed manner as they are inevitably linked and influence each other. Evidently, the exact interconnections between both pandemics need to be locally assessed. For instance, a study in South Africa showed that while lockdown severely impacted HIV testing and ART initiation, ART provision was largely maintained, indicating that the strength of the connection between the virological suppression-related loop and the pandemic, indicated in figure 1, are context-dependent.16publishersversionpublishe

conceptual mapping of a complex adaptive system based on multi-disciplinary expert insights

Funding Information: This study was partially funded by VLIR-UOS. The study sponsors had no role in the study design, the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the paper for publication. Publisher Copyright: © 2022, The Author(s).Background: HIV drug resistance (HIVDR) continues to threaten the effectiveness of worldwide antiretroviral therapy (ART). Emergence and transmission of HIVDR are driven by several interconnected factors. Though much has been done to uncover factors influencing HIVDR, overall interconnectedness between these factors remains unclear and African policy makers encounter difficulties setting priorities combating HIVDR. By viewing HIVDR as a complex adaptive system, through the eyes of multi-disciplinary HIVDR experts, we aimed to make a first attempt to linking different influencing factors and gaining a deeper understanding of the complexity of the system. Methods: We designed a detailed systems map of factors influencing HIVDR based on semi-structured interviews with 15 international HIVDR experts from or with experience in sub-Saharan Africa, from different disciplinary backgrounds and affiliated with different types of institutions. The resulting detailed system map was conceptualized into three main HIVDR feedback loops and further strengthened with literature evidence. Results: Factors influencing HIVDR in sub-Saharan Africa and their interactions were sorted in five categories: biology, individual, social context, healthcare system and ‘overarching’. We identified three causal loops cross-cutting these layers, which relate to three interconnected subsystems of mechanisms influencing HIVDR. The ‘adherence motivation’ subsystem concerns the interplay of factors influencing people living with HIV to alternate between adherence and non-adherence. The ‘healthcare burden’ subsystem is a reinforcing loop leading to an increase in HIVDR at local population level. The ‘ART overreliance’ subsystem is a balancing feedback loop leading to complacency among program managers when there is overreliance on ART with a perceived low risk to drug resistance. The three subsystems are interconnected at different levels. Conclusions: Interconnectedness of the three subsystems underlines the need to act on the entire system of factors surrounding HIVDR in sub-Saharan Africa in order to target interventions and to prevent unwanted effects on other parts of the system. The three theories that emerged while studying HIVDR as a complex adaptive system form a starting point for further qualitative and quantitative investigation.publishersversionpublishe