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Imitation from Observation (IfO) prompts the robot to imitate tasks from unlabeled videos via reinforcement learning (RL). The performance of the IfO algorithm depends on its ability to extract task-relevant representations since images are informative. Existing IfO algorithms extract image representations by using a simple encoding network or pre-trained network. Due to the lack of action labels, it is challenging to design a supervised task-relevant proxy task to train the simple encoding network. Representations extracted by a pre-trained network such as Resnet are often task-irrelevant. In this article, we propose a new approach for robot IfO via multimodal observations. Different modalities describe the same information from different sides, which can be used to design an unsupervised proxy task. Our approach contains two modules: the unsupervised cross-modal representation (UCMR) module and a self-behavioral cloning (self-BC)-based RL module. The UCMR module learns to extract task-relevant representations via a multimodal unsupervised proxy task. The Self-BC for further offline policy optimization collects successful experiences during the RL training. We evaluate our approach on the real robot pouring water task, quantitative pouring task, and pouring sand task. The robot achieves state-of-the-art performance.
The cable-driven parallel mechanism (CDPM) is known as an interesting application in industry to pick and place objects owing to its advantages such as large workspaces. In addition to the advantages of this mechanism, there are some challenges to improving performance by considering constraints in different components, such as the behavior of cables, shape, size of the end effector and base, and model of pulleys and actuators. Moreover, the impact of online geometry reconfiguration must be analyzed. This paper demonstrates the impact of these constraints on the performance of reconfigurable CDPM. The methodology is based on the systematic review and meta-analysis guidelines to report the results. The databases used to find the papers are extracted from Scopus and Google Scholar, using related keywords. As a result, the impact of physical constraints on system performance is discussed. A total of 90 and 37 articles are selected, respectively. After removing duplicates and unrelated papers, 88 studies that met the inclusion criteria are selected for review. Even when considering the physical constraints in modeling the mechanism, simplifications in designing a model for the reconfigurable CDPM generate errors. There is a gap in designing high-performance controllers to track desired trajectories while reconfiguring the geometry, and the satisfaction of physical constraints needs to be satisfied. In conclusion, this review presents several constraints in designing a controller to track desired trajectories and improve performance in future work. This paper presents an integrated controller architecture that includes physical constraints and predictive control.
Anxiety and depression are highly prevalent and comorbid problems in childhood, which deserve greater understanding for effective prevention and treatment. The main aim of the present study was to explore the comorbidity between anxiety and depression symptoms using a novel and valuable approach to study comorbidity, such as network analysis. Specifically, the connectivity between symptoms and possible relevant symptoms was examined through comorbidity estimation and shortest pathway networks, as well as bridge symptoms. This study comprised 281 Spanish-speaking children aged 8–12 years (45.2% girls), whose anxiety and depression symptoms were assessed through specific brief parent-report measures. Analyses revealed that in the comorbidity network, the most central symptoms were related to depression (“No good anymore,” “Could never be as good,” “Hated self,” “Did everything wrong,” “Nobody loved him/her”) or anxiety (“Suddenly feels really scared”). Furthermore, it was found that the most central bridge symptoms, whose activation would play a key role in the activation of other domain symptoms, were anxiety symptoms such as “Trouble going to school” and “Suddenly feels really scared” and depression symptoms, such as “Could never be as good” and “Hated self.” Additionally, the shortest path network suggested the existence of different possible pathways of connection between anxiety and depression symptoms. Overall, these findings help to understand the complexity of the anxiety-depression comorbidity. It suggests the existence of central and bridge symptoms that complement previous studies, which may be potential targets for interventions to prevent and treat childhood anxiety and depression.
To better delineate multiplexed gastrointestinal polymerase chain reaction (PCR) panel (MGPP) diagnostic and therapeutic stewardship for patients undergoing treatment for acute leukemia including indications and benefits of testing, optimal timing, and interpretation of results.
Study design:
We retrieved all MGPP ordered on 662 consecutive patients admitted with newly diagnosed acute leukemia between June 2015 and May 2024.
Setting:
Regional referral center for acute leukemia.
Results:
Fifty-one (17%) of 305 MGPP obtained on the 198 patients who underwent testing identified at least one and 4 (1%) more than one diarrheagenic pathogen. The probability of a positive result was greater if obtained as an outpatient [20/52(38%)], but was not related to type of leukemia, sex, or age. Among the positive results, the pathogens identified included Clostridioides difficile (78% of tests), norovirus (16%), diarrheagenic Escherichia coli (6%), adenovirus 40/41 (4%), and Giardia lamblia (4%). The results of 30 of the 305 tests resulted in a change in treatment (28 C. difficile, 2 G. lamblia). For the MGPP C. difficile results with an accompanying toxin determination, this included treatment following 16/19 tests with a positive toxin result and 11/19 with a negative. Actionable results other than C. difficile were rarely seen in the inpatient population.
Conclusions:
MGPP testing is most useful when administered as an outpatient and of little benefit for inpatients with hospital-onset diarrhea. Since MGPP is sensitive and does not distinguish between colonization and causes of diarrhea, caution is needed in interpretation of results, especially for toxin-negative C. difficile.
The ethical treatment of human remains after excavation is a core debate in archaeology. This project explores the treatment of human remains in some European museums with an aim to support open discussion of complex ethical issues among research and heritage professionals involved in the care of human remains.
We derive an asymptotic expansion for the critical percolation density of the random connection model as the dimension of the encapsulating space tends to infinity. We calculate rigorously the first expansion terms for the Gilbert disk model, the hyper-cubic model, the Gaussian connection kernel, and a coordinate-wise Cauchy kernel.
Antipsychotic medications targeting dopamine receptors were identified 70 years ago. Recent clinical trials have shown that agonists of muscarinic acetylcholinergic receptors can improve both psychotic and negative symptoms in schizophrenia. Here, this new approach to the treatment of schizophrenia is reviewed in anticipation of the drugs being licensed clinically.
Understanding gender disparities in home-based self-employment (HBS) and their links to homeownership and socioeconomic factors is crucial for advancing sustainable development goals (SDGs) in Sub-Saharan Africa, especially Nigeria. This study uses data from the 2010/2011, 2012/13, 2015/16, and 2018/19 waves of the Nigerian General Household Survey (GHS). It employs random effect probit regression, the LASSO method for identifying predictors, and the Blinder–Oaxaca decomposition technique to analyse gender differences in nonlinear binary outcomes. The results show that female business owners are more likely to engage in HBS compared to males, highlighting the importance of gender equality (SDG 5) and decent work (SDG 8). While male entrepreneurs are mainly driven by profit, females prioritise balancing paid and unpaid work, reflecting motivations beyond profit within heterodox economics. Significant gender-differentiated impacts are observed in relation to monthly rent, post-secondary education, dwelling space, energy, and regional locations. Notably, the presence of children significantly increases female involvement in HBS, a trend not seen among males. Marriage also influences female participation, suggesting that marital circumstances and economic benefits play a role. These findings highlight the need for policies addressing gender-specific constraints, challenging traditional gender roles, and promoting inclusive human development within the SDG framework.
Aqueous foams coarsen with time due to gas diffusion through the liquid between the bubbles. The mean bubble size grows, and small bubbles vanish. However, coarsening is little understood for foams with an intermediate liquid content, particularly in the presence of surfactant-induced attractive forces between the bubbles, measured by the interface contact angle where thin films meet the bulk liquid. Rigorous bubble growth laws have yet to be developed, and the evolution of bulk foam properties is unclear. We present a quasistatic numerical model for coarsening in two-dimensional wet foams, focusing on growth laws and related bubble properties. The deformation of bubble interfaces is modelled using a finite-element approach, and the gas flow through both films and Plateau borders is approximated. We give results for disordered two-dimensional wet foams with $256$ to $1024$ bubbles, at liquid fractions from $2\,\%$ to $25\,\%$, beyond the zero-contact-angle unjamming transition, and with contact angles up to $10^\circ$. Simple analytical models for the bubble pressures, film lengths and coarsening growth rates are developed to aid interpretation. If the contact angle is non-zero, we find that a prediction of the coarsening rate approaches a non-zero value as the liquid fraction is increased. We also find that an individual bubble's effective number of neighbours determines whether it grows or shrinks to a good approximation.
This study aims to examine the impact of the Hukou system, a labour mobility-restricting institution, on the decision to engage in non-agricultural self-employment in China, reflecting the dynamic process of labour transition from contractual work to self-employment within the country’s evolving labour market. By using the China Family Panel Studies (CFPS) dataset, the results show that urban migrants, who own rural Hukou but migrate to large cities, are more likely to turn to self-employment than local citizens conditional on individual characteristics. Taking advantage of the 2014 Hukou reform, we provide supporting evidence that Hukou discrimination is a key factor in explaining the higher self-employment rate among representative urban migrants. Further heterogeneous analysis suggests that low-income migrants experience greater constraints imposed by the Hukou system, while high-income level migrants are more likely to turn to self-employment voluntarily.
In recent years, Japan has experienced a series of earthquakes and torrential rain disasters in various regions, and in Gifu City, there is concern about the possibility ofNankai Trough earthquakes in the near future. However, pharmacists’ awareness of disaster preparedness and status of drug stockpiles in pharmacies are not clearly outlined.
Methods
A survey on disaster prevention and stockpiling was conducted in 286 pharmacies in Gifu City. Data were collected from August to the end of October 2022. A simple aggregate was used in the study.
Results
The response rate was 66.8% (191 pharmacies). Among them, 9.9% (19 pharmacies) had stockpiles of medicines for disasters, in which 33.3% of the medicines needed in the early stages of a disaster were above the average overall stockpiling rate. In addition, 2.1% (4 pharmacies) selected medicines according to national or prefectural manuals, and 96.3% (184 pharmacies) preferred to have the “national or local government” bear the cost of stockpiling.
Conclusions
This study allowed us to understand the stockpiling situation of pharmacies in Gifu City in event of a disaster such as the Nankai Trough earthquake, which is likely to occur in the future. Based on these results, it is necessary to consider measures for disaster stockpiling.
In this article, we develop a novel large volatility matrix estimation procedure for analyzing global financial markets. Practitioners often use lower-frequency data, such as weekly or monthly returns, to address the issue of different trading hours in the international financial market. However, this approach can lead to inefficiency due to information loss. To mitigate this problem, our proposed method, called Structured Principal Orthogonal complEment Thresholding (S-POET), incorporates observation structural information for both global and national factor models. We establish the asymptotic properties of the S-POET estimator, and also demonstrate the drawbacks of conventional covariance matrix estimation procedures when using lower-frequency data. Finally, we apply the S-POET estimator to an out-of-sample portfolio allocation study using international stock market data.
We examine the mechanisms responsible for the onset of the three-dimensional mode B instability in the wake behind a circular cylinder. We show that it is possible to explicitly account for the stabilising effect of spanwise viscous diffusion and then demonstrate that the remaining mechanisms involved in this short-wavelength instability are preserved in the limit of zero wavelength. Using the resulting simplified equations, we show that perturbations in different fluid particles interact only through the in-plane viscous diffusion which turns out to have a destabilising effect. We also show that in the presence of viscous diffusion, the closed trajectories which had been conjectured to play a crucial role in the onset of the mode B instability are not actually a prerequisite for the growth of mode B type perturbations. We combine these observations to identify the three essential ingredients for the development of the mode B instability: (i) the amplification of perturbations in the braid regions due to the stretching mechanism; and the spreading of perturbations through (ii) viscous diffusion, and (iii) cross-flow advection which transports fluid between the two braid regions on either side of the cylinder. Finally, we develop a simple criterion that allows the prediction of the regions where three-dimensional short-wavelength perturbations are amplified by the stretching mechanism. The approach used in our study is general and has the potential to give insights into the onset of three-dimensionality via short-wavelength instabilities in other flows.
We conducted a systematic review of the medical, nursing, forensic, and social science literature describing events and processes associated with what happens after a traumatic death in the socio-cultural context of largely Western and high-income societies. These include death notification, why survivors choose to view or not view the body, forensic practices affecting viewing the body, alternatives to viewing, and social and cultural practices following the death. We also describe how elements of these processes may act to increase or lessen some of the negative cognitive and emotional consequences for both survivors and providers. The information presented is applicable to those who may be faced with traumatic deaths, including those who work in medicine, nursing, and law enforcement, as well as first responders, forensic investigators, funeral directors, and the families of the deceased.
Maintaining object grasp stability represents a pivotal challenge within the domain of robotic manipulation and upper-limb prosthetics. Perturbations originating from external sources frequently disrupt the stability of grasps, resulting in slippage occurrences. Also, if the grasping forces are not optimal while controlling the slip, it may result in the deformation of the objects. This study investigates the robustification of a reinforcement learning (RL) policy for implementing intelligent bionic reflex control, i.e., slip and deformation prevention of the grasped objects. RL-derived policies are vulnerable to failures in environments characterized by dynamic variability. To mitigate this vulnerability, we propose a methodology involving the incorporation of an adaptive sliding mode controller into a pre-trained RL policy. By exploiting the inherent invariance property of the sliding mode algorithm in the presence of uncertainties, our approach strengthens the robustness of the RL policies against diverse and dynamic variations. Numerical simulations substantiate the efficacy of our approach in robustifying RL policies trained within simulated environments.
The new mineral popugaevaite Ca3[B5O6(OH)6]FCl2·8H2O was found at the Internatsional’nyi diamond mine, Internatsional’naya kimberlite pipe, Sakha (Yakutia) Republic, Russia. It belongs to the low-temperature hydrothermal mineral assemblage formed in the contact zone between kimberlite and a boron-bearing halite rock. Popugaevaite occurs as veinlets in massive aggregates of ekaterinite and crusts (up to 0.7 mm thick and up to 1 cm × 4 cm in area) on ekaterinite nodules embedded in halite. Other associated minerals are Fe-rich szaibélyite, serpentine, dolomite, pyrrhotite and chalcopyrite. Crude prismatic crystals of popugaevaite are up to 0.3 × 1 mm. The mineral is transparent, colourless, with vitreous lustre and perfect {010} cleavage. It is optically biaxial (–), α 1.502(2), β 1.523(2), γ 1.530(2) and 2Vmeas = 50(10)°. The chemical composition (wt.%, electron-microprobe, boron by ICP-MS, H2O calculated by stoichiometry) is: CaO 28.54, B2O3 28.62, F 3.19, Cl 11.50, H2O 32.83, O = (F,Cl) –3.94, total 100.74. The empirical formula, calculated based on 23 O+F+Cl and 22 H atoms per formula unit, is Ca3.07B4.96O6.03(OH)6F1.01Cl1.96·8H2O. Popugaevaite is monoclinic, space group Pn, a = 8.7055(11), b = 8.1025(11), c = 14.812(2) Å, β = 91.367(7)°, V = 1044.5(2) Å3 and Z = 2. The strongest reflections of the powder X-ray diffraction pattern [d,Å(I,%)(hkl)] are: 8.12(100)(010), 4.058(27)(020), 3.577(15)($\bar 1$21), 2.936(10)(123), 2.834(16)(301, $\bar 1$05) and 2.283(10)(133). The crystal structure was solved based on single-crystal XRD data and refined on powder data by the Rietveld method, Rwp = 0.0058, Rp = 0.0043 and Robs = 0.0241. Popugaevaite is an isostructural analogue of brianroulstonite Ca3[B5O6(OH)6](OH)Cl2·8H2O with F– instead of the OH– group non-bound with boron. The structure is based upon the layers of twelve-membered rings of alternating BO3 triangles and BO2(OH)2 tetrahedra. The mineral is named in honour of the Russian geologist Larisa Anatol’evna Popugaeva (1923–1977), one of the principal discoverers of diamondiferous kimberlite pipes in Yakutia.
In 2003, rescue excavations at Piazzeta dell'Anfiteatro, Trento, identified an extramural funerary area dated to the 5th c. CE. The necropolis yielded 45 coins (3rd–5th c.), most of which were involuntary losses. Owing to the sound stratigraphy of the site, these coins present a reliable sample of coinage circulating in Tridentum during the 5th c. This study presents a brief synthesis of the transformations undergone by the Late Antique city, so as to understand the dynamics attested in Piazzeta dell'Anfiteatro, a description of the stratigraphic units that contained coins, and a detailed analysis of the coins from several perspectives. The aim is to improve our understanding of the Late Antique monetary history of the city and Trentino's territory.