277 research outputs found
Dexterous Soft Hands Linearize Feedback-Control for In-Hand Manipulation
This paper presents a feedback-control framework for in-hand manipulation
(IHM) with dexterous soft hands that enables the acquisition of manipulation
skills in the real-world within minutes. We choose the deformation state of the
soft hand as the control variable. To control for a desired deformation state,
we use coarsely approximated Jacobians of the actuation-deformation dynamics.
These Jacobian are obtained via explorative actions. This is enabled by the
self-stabilizing properties of compliant hands, which allow us to use linear
feedback control in the presence of complex contact dynamics. To evaluate the
effectiveness of our approach, we show the generalization capabilities for a
learned manipulation skill to variations in object size by 100 %, 360 degree
changes in palm inclination and to disabling up to 50 % of the involved
actuators. In addition, complex manipulations can be obtained by sequencing
such feedback-skills.Comment: Accepted at 2023 IEEE/RSJ International Conference on Intelligent
Robots and Systems (IROS
Countering avoidance strategies used by fishers to avoid detection during illegal fishing
Non-compliers typically avoid detection by authorities, benefiting from increased catch and income. While detection-avoidance strategies (e.g., secret compartments to hide illegal catch) are commonly used in the nature conservation context, they remain largely unstudied. We address this knowledge gap in three sections. First, we introduce and hypothesize the likelihood of non-compliers adopting detection-avoidance strategies in the broader conservation context. Second, we identify and categorize detection-avoidance strategies used by small-scale fishers. Third, we provide recommendations for countering detection-avoidance strategies (i.e., countermeasures). Because countermeasures are context-specific, they should be informed through systematic processes such as the intelligence cycle. If used properly, enforcement activities and countermeasures can help build voluntary compliance, particularly through procedural justice, or acting in a way that users perceive as fair and just
Drinking and Flying: Does Alcohol Consumption Affect the Flight and Echolocation Performance of Phyllostomid Bats?
In the wild, frugivorous and nectarivorous bats often eat fermenting fruits and nectar, and thus may consume levels of ethanol that could induce inebriation. To understand if consumption of ethanol by bats alters their access to food and general survival requires examination of behavioural responses to its ingestion, as well as assessment of interspecific variation in those responses. We predicted that bats fed ethanol would show impaired flight and echolocation behaviour compared to bats fed control sugar water, and that there would be behavioural differences among species. (Chiroptera, Phyllostomidae) sugar water (44 g of table sugar in 500 ml of water) or sugar water with ethanol before challenging them to fly through an obstacle course while we simultaneously recorded their echolocation calls. We used bat saliva, a non-invasive proxy, to measure blood ethanol concentrations ranging from 0 to >0.3% immediately before flight trials. Flight performance and echolocation behaviour were not significantly affected by consumption of ethanol, but species differed in their blood alcohol concentrations after consuming it.The bats we studied display a tolerance for ethanol that could have ramifications for the adaptive radiation of frugivorous and nectarivorous bats by allowing them to use ephemeral food resources over a wide span of time. By sampling across phyllostomid genera, we show that patterns of apparent ethanol tolerance in New World bats are broad, and thus may have been an important early step in the evolution of frugivory and nectarivory in these animals
Modelling the impact of antimalarial quality on the transmission of sulfadoxine-pyrimethamine resistance in Plasmodium falciparum
Background: The use of poor quality antimalarial medicines, including the use of non-recommended medicines for treatment such as sulfadoxine-pyrimethamine (SP) monotherapy, undermines malaria control and elimination efforts. Furthermore, the use of subtherapeutic doses of the active ingredient(s) can theoretically promote the emergence and transmission of drug resistant parasites.
Methods: We developed a deterministic compartmental model to quantify the impact of antimalarial medicine quality on the transmission of SP resistance, and validated it using sensitivity analysis and a comparison with data from Kenya collected in 2006. We modelled human and mosquito population dynamics, incorporating two Plasmodium falciparum subtypes (SP-sensitive and SP-resistant) and both poor quality and good quality (artemether-lumefantrine) antimalarial use.
Findings: The model predicted that an increase in human malaria cases, and among these, an increase in the proportion of SP-resistant infections, resulted from an increase in poor quality SP antimalarial use, whether it was full- or half-dose SP monotherapy.
Interpretation: Our findings suggest that an increase in poor quality antimalarial use predicts an increase in the transmission of resistance. This highlights the need for stricter control and regulation on the availability and use of poor quality antimalarial medicines, in order to offer safe and effective treatments, and work towards the eradication of malaria
Animal spirits and credit cycles
In this paper we extend the behavioral macroeconomic model as proposed by De Grauwe (2012) to include a banking sector. The behavioral model takes the view that agents have limited cognitive abilities. As a result, it is “rational” to use simple forecasting rules and to subject the use of these rules to a fitness test. Agents are then driven to select the rule that performs best. The behavioral model produces endogenous and self-fulfilling movements of optimism and pessimism (animal spirits). Our main result is that the existence of banks intensifies these movements, creating a greater scope for booms and busts. Thus, banks do not create but amplify animal spirits. We find that increases in the equity ratios of banks tend to reduce the importance of animal spirits over the business cycle. The other policy conclusion we derive from our results is that the central bank has an important responsibility for stabilising output: output stabilization is an instrument to “tame the animal spirits”. This has the effect of improving the trade-off between inflation and output volatility
tert-Butyl 2-methyl-2-(4-methylbenzoyl)propanoate
The title compound, C16H22O3, is bent with a dihedral angle of 75.3 (1)° between the mean planes of the benzene ring and a group encompassing the ester functionality (O=C—O—C). In the crystal, the molecules are linked into infinite chains held together by weak C—H⋯O hydrogen-bonded interactions between an H atom on the benzene ring of one molecule and an O atom on the ketone functionality of an adjacent molecule. The chains are arranged with neighbouring tert-butyl and dimethyl groups on adjacent chains exhibiting hydrophobic stacking, with short C—H⋯H—C contacts (2.37 Å) between adjacent chain
Closing the compliance gap in marine protected areas with human behavioural sciences
Advocates, practitioners and policy-makers continue to use and advocate for marine protected areas (MPAs) to meet global ocean protection targets. Yet many of the worlds MPAs, and especially no-take MPAs, are plagued by poaching and ineffective governance. Using a global dataset on coral reefs as an example, we quantify the potential ecological gains of governing MPAs to increase compliance, which we call the ‘compliance gap’. Using ecological simulations based on model posteriors of joint Bayesian hierarchical models, we demonstrate how increased compliance in no-take MPAs could nearly double target fish biomass (91% increases in median fish biomass), and result in a 292% higher likelihood of encountering top predators. Achieving these gains and closing the compliance gap necessitates a substantial shift in approach and practice to go beyond optimizing enforcement, and towards governing for compliance. This will require engaging and integrating a broad suite of actors, principles, and practices across three key domains: (i)) harnessing social influence, (ii) integrating equity principles, and (iii) aligning incentives through market-based instruments. Empowering and shaping communication between actor groups (e.g., between fishers, practitioners, and policy-makers) using theoretically underpinned approaches from the behavioural sciences is one of the most essential, but often underserved aspects of governing MPAs. We therefore close by highlighting how this cross-cutting tool could be further integrated in governance to bolster high levels of compliance in MPAs
Ibrutinib Plus Venetoclax in Relapsed/Refractory Chronic Lymphocytic Leukemia: The CLARITY Study.
PURPOSE:The treatment of chronic lymphocytic leukemia (CLL) has been revolutionized by targeted therapies that either inhibit proliferation (ibrutinib) or reactivate apoptosis (venetoclax). Both significantly improve survival in CLL and replace chemoimmunotherapy for many patients. However, individually, they rarely lead to eradication of measurable residual disease (MRD) and usually are taken indefinitely or until progression. We present the CLARITY trial that combined ibrutinib with venetoclax to eradicate detectable CLL with the intention of stopping therapy. PATIENTS AND METHODS:CLARITY is a phase II trial that combined ibrutinib with venetoclax in patients with relapsed or refractory CLL. The primary end point was eradication of MRD after 12 months of combined therapy. Key secondary end points were response by International Workshop on CLL criteria, safety, and progression-free and overall survival. RESULTS:In 53 patients after 12 months of ibrutinib plus venetoclax, MRD negativity (fewer than one CLL cell in 10,000 leukocytes) was achieved in the blood of 28 (53%) and the marrow of 19 (36%). Forty-seven patients (89%) responded, and 27 (51%) achieved a complete remission. After a median follow-up of 21.1 months, one patient progressed, and all patients were alive. A single case of biochemical tumor lysis syndrome was observed. Other adverse effects were mild and/or manageable and most commonly were neutropenia or GI events. CONCLUSION:The combination of ibrutinib plus venetoclax was well tolerated in patients with relapsed or refractory CLL. There was a high rate of MRD eradication that led to the cessation of therapy in some patients. The progression-free and overall survival rates are encouraging for relapsed and refractory CLL
Why Should Ecosystem Services Be Governed to Support Poverty Alleviation? Philosophical Perspectives on Positions in the Empirical Literature
In light of trade-offs related to the allocation of ecosystem services we investigate the prevalent norms that are drawn upon to justify why ecosystem governance should prioritise poverty alleviation. We are specifically concerned with poverty alleviation because we consider this an urgent problem of justice. We review empirical literature on social trade-offs in ecosystem services governance in order to identify the prevalent conceptions of justice that inform scholarly assessments of current practice. We find that empirical studies do present specific notions of justice as desirable benchmarks for ecosystem services governance but that they rarely attempt to spell out the precise meaning of these notions or what makes them desirable. For those notions of justice that we identify in this literature - sufficientarianism, egalitarianism and participatory approaches - we draw on philosophical justice literature in order to better articulate the normative arguments that could support them and to be more precise about the kind of actions and expectations that they invoke. Moreover, we point to some striking normative silences in the ecosystem services literature. We conclude that the ecosystem services justice discourse would benefit from more conceptual clarity and a broader examination of different aspects of justice
- …