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Wearable devices are fast evolving to address mobility and autonomy needs of elderly people who would benefit from physical assistance. Recent developments in soft robotics provide important opportunities to develop soft exoskeletons (also called exosuits) to enable both physical assistance and improved usability and acceptance for users. The XoSoft EU project has developed a modular soft lower limb exoskeleton to assist people with low mobility impairments. In this paper, we present the design of a soft modular lower limb exoskeleton to improve person’s mobility, contributing to independence and enhancing quality of life. The novelty of this work is the integration of quasi-passive elements in a soft exoskeleton. The exoskeleton provides mechanical assistance for subjects with low mobility impairments reducing energy requirements between 10% and 20%. Investigation of different control strategies based on gait segmentation and actuation elements is presented. A first hip–knee unilateral prototype is described, developed, and its performance assessed on a post-stroke patient for straight walking. The study presents an analysis of the human–exoskeleton energy patterns by way of the task-based biological power generation. The resultant assistance, in terms of power, was 10.9% ± 2.2% for hip actuation and 9.3% ± 3.5% for knee actuation. The control strategy improved the gait and postural patterns by increasing joint angles and foot clearance at specific phases of the walking cycle.
Because the demand for intensive care unit (ICU) beds exceeds the supply in general, and because of the formidable costs of that level of care, clinicians face ethical issues when rationing this kind of care not only at the point of admission to the ICU, but also after the fact. Under what conditions—if any—may patients be denied admission to the ICU or removed after admission? One professional medical group has defended a rule of “first come, first served” in ICU admissions, and this approach has numerous moral considerations in its favor. We show, however, that admission to the ICU is not in and of itself guaranteed; we also show that as a matter of principle, it can be morally permissible to remove certain patients from the ICU, contrary to the idea that because they were admitted first, they are entitled to stay indefinitely through the point of recovery, death, or voluntary withdrawal. What remains necessary to help guide these kinds of decisions is the articulation of clear standards for discontinuing intensive care, and the articulation of these standards in a way consistent with not only fiduciary and legal duties that attach to clinical care but also with democratic decision making processes.
Depression and metabolic syndrome (MetS) are frequently comorbid disorders that are independently associated with premature mortality. Conversely, cardiorespiratory fitness (CRF) is associated with reduced mortality risk. These factors may interact to impact mortality; however, their effects have not been assessed concurrently. This analysis assessed the mortality risk of comorbid depression/MetS and the effect of CRF on mortality in those with depression/MetS.
Prospective study of 47 702 adults in the Cooper Center Longitudinal Study. Mortality status was attained from the National Death Index. History of depression was determined by patient response (yes or no) to a standardized medical history questionnaire. MetS was categorized using the American Heart Association/National Heart, Lung, and Blood Institute criteria. CRF was estimated from the final speed/grade of a treadmill graded exercise test.
13.9% reported a history of depression, 21.4% met criteria for MetS, and 3.0% met criteria for both MetS and history of depression. History of depression (HR = 1.24, p = 0.003) and MetS (HR = 1.28, p < 0.001) were independently associated with an increased mortality risk, with the greatest mortality risk among individuals with both a history of depression and MetS (HR = 1.59, p < 0.001). Higher CRF was associated with a significantly lower risk of mortality (p < 0.001) in all individuals, including those with MetS and/or a history of depression.
Those with higher levels CRF had reduced mortality risk in the context of depression/MetS. Interventions that improve CRF could have substantial impact on the health of persons with depression/MetS.
Oxtotitlán Cave paintings have been considered among the earliest in Mesoamerica on stylistic grounds, but confirmation of this hypothesis through absolute dating has not been attempted until now. We describe the application of advanced radiocarbon strategies developed for situations such as caves with high carbon backgrounds. Using a low-temperature plasma oxidation system, we dated both the ancient paint and the biogenic rock coatings that cover the paint layers at Oxtotitlán. Our research has significantly expanded the time frame for the production of polychrome rock paintings encompassing the Early Formative and Late Formative/Early Classic periods, statistically spanning a long era from before ca. 1500 cal B.C. to cal A.D. 600.
This paper reports the first chronological assessment of the Christian catacombs of Rome by radiocarbon dating. The organic materials dated were found in a set of burial rooms in the so-called Liberian region of the catacombs of St. Callixtus on the Appian Way. 14C dating of small samples by accelerator mass spectrometry (AMS) represents a major advance over traditional archaeological dating methods used in catacomb archaeology; however, AMS 14C dating raises questions about sample reliability and chronological evaluation. We briefly explore these questions.
This paper reports on the first chronological assessment of the Jewish Catacombs of the ancient Rome performed by accelerator mass spectrometry (AMS) dating of small-size charcoal fragments scattered in the mortar used for sealing off the graves in the Villa Torlonia Catacomb complex. The significance of the obtained 14C readings has been carefully evaluated by taking into consideration the known technologies of quicklime production during Roman and recent times. The new data are of great concern for providing evidence that the Jewish catacombs were used for burial since the first century AD, thus some two centuries prior to the period traditionally believed to be the starting point of burial in the Jewish catacombs of ancient Rome. Such a significant aging of the Jewish catacombs could result in a deep re-examination of the current understanding of the beginning and the evolution of the custom of catacomb burial in both Jewish and early Christian communities in Rome.
In this paper, we discuss how the radiocarbon dating of soot on oil lamps can help determine the chronology of the Jewish catacombs of Rome. We also explore the ramifications of our work for the typological study of Roman period terracotta lamps.
This paper reports a further chronological assessment of the Christian catacombs of Rome by radiocarbon-dated organic materials in the so-called Liberian region of the catacombs of St. Callixtus on the Appian Way. 14C dates of various types of organic material are discussed and related to ages derived from numismatic evidence and epigraphic remains. The results show that this area of the catacombs of St. Callixtus is older than assumed by previous scholarship. We therefore conclude that the appellation “Liberian region” is a misnomer.
The megafauna and associated behavioral traces of two deep-sea benthic environments, the central Arctic and Antarctic, with a surface primary productivity differential of 104 were compared to assess the role of food availability in foraging strategy and community structure. Bottom photographs, analyzed for megafauna and trace density and diversity at comparable depths in the Arctic Canada Basin and the Antarctic Bellingshausen Basin, indicated that trace frequency was inversely proportional to organism density but that trace diversity directly reflected organism diversity. Those traces identified in the fossil record to represent efficient foraging strategies, i.e., the Nereites facies, were conspicuously absent at all depths in the Arctic and present at all depths in the Antarctic, in contradiction of the paradigm of increasing behavioral complexity and sediment exploitation as food availability decreases. Presence or absence of surface-grazing organisms seems to exert a greater influence on trace diversity than depth or nutrient supply. Trace density, however, may reflect episodic sedimentation events which intermittently influence the deep-sea trophic regime.
The bilayer pseudospin field effect transistor (BiSFET) is intended to enable much lower voltage and power operation than possible with complementary metal–oxide–semiconductor (CMOS) field effect transistor (FET)-based logic [1, 2]. The ultimate limits of CMOS are not due to fabrication technology limitations. Rather, they are intrinsic to its operating principles, defined by basic physics such as charge carrier thermionic emission over the channel barrier and quantum mechanical tunneling through it. New operating principles are required. The BiSFET relies on the possibility of room temperature excitonic (electron-hole) superfluid condensation in two dielectrically separated graphene layers [3, 4]. While the physics is interesting in its own right, from the device point of view this many-body physics brings with it the possibility of a strong sensitivity to sub-thermal voltages (sub-kBT/q voltages, where kB is Boltzmann’s constant, T is the temperature in Kelvin, and q is the magnitude of electron charge) in the current–voltage (I–V) characteristics [5–7]. With power consumption proportional to the square of voltage, use of voltages on the scale of or less than room temperature kBT/q ≈ 26 mV offers order of magnitude reductions in switching energies as compared to even end-of-the roadmap CMOS . Circuit simulation with 25 mV power supplies show switching energies on the scale of 10 zeptojoules (zJ) per BiSFET (where 1 zJ = 10–21 J = 10–3 aJ)! However, with this potential for voltage reduction also come I–V characteristics much different from those of MOSFETs that must be worked around at worst, and may provide new circuit opportunities at best. In terms of interconnects, information would continue to be passed via charge among devices. In this way, BiSFETs would also be compatible with existing electronic devices after voltage level shifts.
In North America, terrestrial records of biodiversity and climate change that span Marine Oxygen Isotope Stage (MIS) 5 are rare. Where found, they provide insight into how the coupling of the ocean–atmosphere system is manifested in biotic and environmental records and how the biosphere responds to climate change. In 2010–2011, construction at Ziegler Reservoir near Snowmass Village, Colorado (USA) revealed a nearly continuous, lacustrine/wetland sedimentary sequence that preserved evidence of past plant communities between ~140 and 55 ka, including all of MIS 5. At an elevation of 2705 m, the Ziegler Reservoir fossil site also contained thousands of well-preserved bones of late Pleistocene megafauna, including mastodons, mammoths, ground sloths, horses, camels, deer, bison, black bear, coyotes, and bighorn sheep. In addition, the site contained more than 26,000 bones from at least 30 species of small animals including salamanders, otters, muskrats, minks, rabbits, beavers, frogs, lizards, snakes, fish, and birds. The combination of macro- and micro-vertebrates, invertebrates, terrestrial and aquatic plant macrofossils, a detailed pollen record, and a robust, directly dated stratigraphic framework shows that high-elevation ecosystems in the Rocky Mountains of Colorado are climatically sensitive and varied dramatically throughout MIS 5.
Using the 3D information provided by photometric or spectroscopic weak lensing surveys, it has become possible in the last few years to address the problem of mapping the matter density contrast in three dimensions from gravitational lensing. We recently proposed a new non linear sparsity based reconstruction method allowing for high resolution reconstruction of the over-density. This new technique represents a significant improvement over previous linear methods and opens the way to new applications of 3D weak lensing density reconstruction. In particular, we demonstrate that for the first time reconstructed over-density maps can be used to detect and characterise galaxy clusters in mass and redshift.