Input/output selection for planar tensegrity models

A systematic method of selecting sensors and actuators is produced, efficiently selecting inputs and outputs that guarantee a desired level of performance in the ∞-norm sense. The method employs an efficiently computable necessary and sufficient existence condition, using an effective search strategy. The search strategy is based on a method to generate all so-called minimal dependent sets. This method is applied to tensegrity structures. Tensegrity structures are a prime example for application of techniques that address structural problems, because they offer a lot of flexibility in choosing actuators/sensors and in choosing their mechanical structure. The selection method is demonstrated with results for a 3 stage planar tensegrity structure where all 26 tendons can be used as control device, be it actuator, sensor, or both, making up 52 devices from which to choose. In our set-up it is easy to require devices to be selected as colocated pairs, and to analyze the performance penalty associated with this restriction. Two performance criteria were explored, one is related to the dynamical stiffness of the structure, the other to vibration isolation. The optimal combinations of sensors and actuators depend on the design specifications and are really different for both performance criteria

Is the economic freedom fighters’ brand of populism transforming political discourse in South Africa?

The arrival of the Economic Freedom Fighters (EFF), self-identified as a radical party of the far left, has shaken up South Africa’s political system and sought to undermine the accepted political norms. Some have speculated that the country’s largest parties would alter their political discourse to ward off the challenge. New research illustrates that the two established political parties have resisted the temptation to engage in similar rhetorical strategies. However, there is some evidence that these parties have reformed their programmatic offerings and behaviour to thwart the EFF’s appeal

A 'Human-in-the-Loop' Mobile Image Recognition Application for Rapid Scanning of Water Quality Test Results

This paper describes an interactive system for drinking water quality testing in small community supplies, particularly in the developing world. The system combines a lowcost field test (the Aquatest field kit), a mobile phone for data processing and communications, and a human operator who is able to react immediately to a test result. Once a water sample has been collected and incubated, the mobile phone camera is used to 'scan' the test and obtain the result, which is displayed to the user along with information about the health implications of the water quality. Initial prototypes, while not yet sufficiently robust for real-world use, demonstrate that the system is technically feasible. This opens up interesting possibilities for wider use of 'human-in-the-loop' sensor systems in environmental monitoring

Drivers of land use change and household determinants of sustainability in smallholder farming systems of Eastern Uganda

Smallholder farming systems in sub-Saharan Africa have undergone changes in land use, productivity and sustainability. Understanding of the drivers that have led to changes in land use in these systems and factors that influence the systems’ sustainability is useful to guide appropriate targeting of intervention strategies for improvement. We studied low input Teso farming systems in eastern Uganda from 1960 to 2001 in a place-based analysis combined with a comparative analysis of similar low input systems in southern Mali. This study showed that policy-institutional factors next to population growth have driven land use changes in the Teso systems, and that nutrient balances of farm households are useful indicators to identify their sustainability. During the period of analysis, the fraction of land under cultivation increased from 46 to 78%, and communal grazing lands nearly completely disappeared. Cropping diversified over time; cassava overtook cotton and millet in importance, and rice emerged as an alternative cash crop. Impacts of political instability, such as the collapse of cotton marketing and land management institutions, of communal labour arrangements and aggravation of cattle rustling were linked to the changes. Crop productivity in the farming systems is poor and nutrient balances differed between farm types. Balances of N, P and K were all positive for larger farms (LF) that had more cattle and derived a larger proportion of their income from off-farm activities, whereas on the medium farms (MF), small farms with cattle (SF1) and without cattle (SF2) balances were mostly negative. Sustainability of the farming system is driven by livestock, crop production, labour and access to off-farm income. Building private public partnerships around market-oriented crops can be an entry point for encouraging investment in use of external nutrient inputs to boost productivity in such African farming systems. However, intervention strategies should recognise the diversity and heterogeneity between farms to ensure efficient use of these external inputs

Tamoxifen use and potential effects on liver parenchyma:A long-term prospective transient elastographic evaluation

Tamoxifen is a commonly prescribed drug in both early and metastatic breast cancer. Prospective studies in Asian populations demonstrated that tamoxifen‐related liver steatosis occurred in more than 30% of the patients within 2 years after start of treatment. No well‐designed prospective studies on potential tamoxifen‐related liver steatosis have been conducted in Caucasian patients so far. Therefore, our prospective study aimed to assess the incidence of tamoxifen‐related liver steatosis for a period of 2 years in a population of Caucasian breast cancer patients treated with tamoxifen. Patients with an indication for adjuvant treatment with tamoxifen were included in this study. Data were collected at 3 months (T1) and at 2 years (T2) after start of tamoxifen treatment (follow‐up period of 21 months). For the quantification of liver steatosis, patients underwent liver stiffness measurement by transient elastography with simultaneous controlled attenuation parameter (CAP) determination using the FibroScan. A total of 95 Caucasian breast cancer patients were included in this evaluation. Liver steatosis was observed in 46 of 95 (48%) and 48 of 95 (51%) of the patients at T1 and T2, respectively. No clinically relevant increase in liver steatosis was observed during the treatment period of 2 years with tamoxifen (median CAP = 243 ± 49 dB/m (T1) and 253 ± 55 dB/m (T2), respectively; p = 0.038). Conclusion: In this prospective longitudinal study in Caucasian breast cancer patients, no clinically relevant alterations in liver steatosis in terms of CAP values and liver/lipid parameters were observed after 2 years of tamoxifen treatment. This study therefore demonstrates an absence of tamoxifen‐related adverse events such as steatosis and (early) development of fibrosis or cirrhosis during a treatment period of at least 2 years

Gastric Acid Suppressive Therapy and Community-Acquired Pneumonia, Etiology and Outcome

Background: Community acquired pneumonia (CAP) is an infection of the pulmonary parenchyma that can be caused by various microbial pathogens. Co-morbidity and medication are related to specific pathogens. Patients on gastric acid suppressive therapy have an increased risk to develop CAP. We aimed to assess whether there are specific pathogens independently associated with gastric acid suppressive therapy and its impact on infection severity. Methods: From December 2007 to January 2010, all subjects consulting the emergency care unit of a general hospital in the south of the Netherlands with a suspected CAP were prospectively registered. Each patient underwent chest radiography. Sputum, urine, nose swabs and blood samples were obtained for microbial culture, antigen detection and polymerase chain reaction techniques, respectively. To study the severity of CAP upon presentation, the validated CURB-65 score was calculated. Furthermore, we assessed hospital or intensive care admission, length of hospitalization and in-hospital mortality. We evaluated the association between use of acid suppressive therapy and microbial aetiology of CAP and severity of illness with logistic regression analysis. Results: The final cohort comprised 463 patients with CAP, defined as presence of infiltrate on chest radiography and/ or microbial aetiology. Overall 136 patients (29%) used acid suppressive therapy, mainly proton pump inhibitors (97%). Patients with acid suppressive therapy more frequently had an infection with Streptococcus pneumoniae (28% vs. 14%) and Haemophilus influenzae (10% vs. 6%), and less frequently with Coxiella burnetii (8% vs. 19%) or H1N1 influenza A virus (2% vs. 7%) in comparison to those without acid suppressive therapy. After adjustment for baseline differences, the risk of proton pump inhibitor users being infected with S. pneumonia was 2.18 times (95%Confidence Interval(CI): 1.2-3.6) higher compared to those not on acid suppressive therapy. Patients using more than one defined daily dose of a PPI had a 1.48-fold increased risk of a S. pneumoniae infection compared with patients using the defined daily dose (95%CI:1.1-2.0). No risk between PPI use and any other microbial pathogen was found. Patients with acid suppressive therapy had on average higher CURB-65 scores, longer hospital stay and subsequently a case fatality rate of 11% vs. 4% compared to those not using acid suppressive therapy. Conclusions. Proton pump inhibitor therapy predisposes with community acquired S. pneumoniae pneumonia, and was associated with higher morbidity

Performance of acute respiratory distress syndrome definitions in a high acuity paediatric intensive care unit

BACKGROUND: For years, paediatric critical care practitioners used the adult American European Consensus Conference (AECC) and revised Berlin Definition (BD) for acute respiratory distress syndrome (ARDS) to study the epidemiology of paediatric ARDS (PARDS). In 2015, the paediatric specific definition, Paediatric Acute Lung Injury Consensus Conference (PALICC) was developed. The use of non-invasive metrics of oxygenation to stratify disease severity were introduced in this definition, although this potentially may lead to a confounding effect of disease severity since it is more common to place indwelling arterial lines in sicker patients. We tested the hypothesis that PALICC outperforms AECC/BD in our high acuity PICU, which employs a liberal use of indwelling arterial lines and high-frequency oscillatory ventilation (HFOV). METHODS: We retrospectively collected data from children < 18 years mechanically ventilated for at least 24 h in our tertiary care, university-affiliated paediatric intensive care unit. The primary endpoint was the difference in the number of PARDS cases between AECC/BD and PALICC. Secondary endpoints included mortality and ventilator free days. Performance was assessed by the area under the receiver operating characteristics curve (AUC-ROC). RESULTS: Data from 909 out of 2433 patients was eligible for analysis. AECC/BD identified 35 (1.4%) patients (mortality 25.7%), whereas PALICC identified 135 (5.5%) patients (mortality 14.1%). All but two patients meeting AECC/Berlin criteria were also identified by PALICC. Almost half of the cohort (45.2%) had mild, 33.3% moderate and 21.5% severe PALICC PARDS at onset. Highest mortality rates were seen in patients with AECC acute lung injury (ALI)/mild Berlin and severe PALICC PARDS. The AUC-ROC for Berlin was the highest 24 h (0.392 [0.124–0.659]) after onset. PALICC showed the highest AUC-ROC at the same moment however higher than Berlin (0.531 [0.345–0.716]). Mortality rates were significantly increased in patients with bilateral consolidations (9.3% unilateral vs 26.3% bilateral, p = 0.025). CONCLUSIONS: PALICC identified more new cases PARDS than the AECC/Berlin definition. However, both PALICC and Berlin performed poorly in terms of mortality risk stratification. The presence of bilateral consolidations was associated with a higher mortality rate. Our findings may be considered in future modifications of the PALICC criteria. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12931-021-01848-z

Mosquito-borne arboviruses of African origin : review of key viruses and vectors

Key aspects of 36 mosquito-borne arboviruses indigenous to Africa are summarized, including lesser or poorly-known viruses which, like Zika, may have the potential to escape current sylvatic cycling to achieve greater geographical distribution and medical importance. Major vectors are indicated as well as reservoir hosts, where known. A series of current and future risk factors is addressed. It is apparent that Africa has been the source of most of the major mosquito-borne viruses of medical importance that currently constitute serious global public health threats, but that there are several other viruses with potential for international challenge. The conclusion reached is that increased human population growth in decades ahead coupled with increased international travel and trade is likely to sustain and increase the threat of further geographical spread of current and new arboviral disease.http://www.parasitesandvectors.comam2018Medical VirologySchool of Health Systems and Public Health (SHSPH)Veterinary Tropical Disease

Short-term effects of neuromuscular blockade on global and regional lung mechanics, oxygenation and ventilation in pediatric acute hypoxemic respiratory failure

Background: Neuromuscular blockade (NMB) has been shown to improve outcome in acute respiratory distress syndrome (ARDS) in adults, challenging maintaining spontaneous breathing when there is severe lung injury. We tested in a prospective physiological study the hypothesis that continuous administration of NMB agents in mechanically ventilated children with severe acute hypoxemic respiratory failure (AHRF) improves the oxygenation index without a redistribution of tidal volume VT toward non-dependent lung zones. Methods: Oxygenation index, PaO2/FiO(2) ratio, lung mechanics (plateau pressure, mean airway pressure, respiratory system compliance and resistance), hemodynamics (heart rate, central venous and arterial blood pressures), oxygenation [ oxygenation index (OI), PaO2/FiO(2) and SpO(2)/FiO(2)], ventilation (physiological dead space-to-VT ratio) and electrical impedance tomography measured changes in end-expiratory lung volume (EELV), and VT distribution was measured before and 15 min after the start of continuous infusion of rocuronium 1 mg/kg. Patients were ventilated in a time-cycled, pressure-limited mode with pre-set VT. All ventilator settings were not changed during the study. Results: Twenty-two patients were studied (N = 18 met the criteria for pediatric ARDS). Median age (25-75 interquartile range) was 15 (7.8-77.5) weeks. Pulmonary pathology was present in 77.3%. The median lung injury score was 9 (8-10). The overall median CoV and regional lung filling characteristics were not affected by NMB, indicating no ventilation shift toward the non-dependent lung zones. Regional analysis showed a homogeneous time course of lung inflation during inspiration, indicating no tendency to atelectasis after the introduction of NMB. NMB decreased the mean airway pressure (p = 0.039) and OI (p = 0.039) in all patients. There were no significant changes in lung mechanics, hemodynamics and EELV. Subgroup analysis showed that OI decreased (p = 0.01) and PaO2/FiO(2) increased (p = 0.02) in patients with moderate or severe PARDS. Conclusions: NMB resulted in an improved oxygenation index in pediatric patients with AHRF. Distribution of VT and regional lung filling characteristics were not affected