1,558 research outputs found
A New Family of Versatile Magnetic Building Blocks for Functional Molecular Materials
National audienc
A quantitative taxonomy of human hand grasps
Background: A proper modeling of human grasping and of hand movements is fundamental for robotics,
prosthetics, physiology and rehabilitation. The taxonomies of hand grasps that have been proposed in scientific
literature so far are based on qualitative analyses of the movements and thus they are usually not quantitatively
justified.
Methods: This paper presents to the best of our knowledge the first quantitative taxonomy of hand grasps based on
biomedical data measurements. The taxonomy is based on electromyography and kinematic data recorded from 40
healthy subjects performing 20 unique hand grasps. For each subject, a set of hierarchical trees are computed for
several signal features. Afterwards, the trees are combined, first into modality-specific (i.e. muscular and kinematic)
taxonomies of hand grasps and then into a general quantitative taxonomy of hand movements. The modality-specific
taxonomies provide similar results despite describing different parameters of hand movements, one being muscular
and the other kinematic.
Results: The general taxonomy merges the kinematic and muscular description into a comprehensive hierarchical
structure. The obtained results clarify what has been proposed in the literature so far and they partially confirm the
qualitative parameters used to create previous taxonomies of hand grasps. According to the results, hand movements
can be divided into five movement categories defined based on the overall grasp shape, finger positioning and
muscular activation. Part of the results appears qualitatively in accordance with previous results describing kinematic
hand grasping synergies.
Conclusions: The taxonomy of hand grasps proposed in this paper clarifies with quantitative measurements what
has been proposed in the field on a qualitative basis, thus having a potential impact on several scientific fields
Dihydropteroate synthase gene mutations in Pneumocystis and sulfa resistance
Pneumocystis pneumonia (PCP) remains a major cause of illness and death in HIV-infected persons. Sulfa drugs, trimethoprim-sulfamethoxazole (TMP-SMX) and dapsone are mainstays of PCP treatment and prophylaxis. While prophylaxis has reduced the incidence of PCP, its use has raised concerns about development of resistant organisms. The inability to culture human Pneumocystis, Pneumocystis jirovecii, in a standardized culture system prevents routine susceptibility testing and detection of drug resistance. In other microorganisms, sulfa drug resistance has resulted from specific point mutations in the dihydropteroate synthase (DHPS) gene. Similar mutations have been observed in P. jirovecii. Studies have consistently demonstrated a significant association between the use of sulfa drugs for PCP prophylaxis and DHPS gene mutations. Whether these mutations confer resistance to TMP-SMX or dapsone plus trimethoprim for PCP treatment remains unclear. We review studies of DHPS mutations in P. jirovecii and summarize the evidence for resistance to sulfamethoxazole and dapsone
A novel Smart Home Energy Management system: Cooperative neighbourhood and adaptive renewable energy usage
Energy usage optimization in Smart Homes is a
critical problem: over 30% of the energy consumption of the
world resides in the residential sector. Usage awareness and
manual appliance control alone are able to reduce consumption
by 15%. This result could be improved if appliance control is
automatic, especially if renewable sources are present locally.
In this paper, a Smart Home Energy Management system that
aims at automatically controlling appliances in groups of smart
homes belonging to the same neighborhood is proposed. Not
only is electric power distribution considered, but also renewable
energy sources such as wind micro-turbines and solar panels.
The proposed strategy relies on two algorithms. The Cost Saving
Task Scheduling algorithm is aimed at scheduling high-power
controllable loads during off-peak hours, taking into account the
expected usage of the non-controllable appliances such as fridge,
oven, etc. This algorithm is run whenever a new need of energy
from a controllable load is detected. The Renewable Source
Power Allocation algorithm re-allocated the starting time of
controllable loads whenever surplus of renewable source power is
detected making use of a distributed max-consensus negotiation.
Performance evaluation of the algorithms tested proves that the
proposed approach provides an energy cost saving that goes
between 35% and 65% with reference to the case where no
automatic control is used
Analysis of the fatigue strength under two load levels of a stainless steel based on energy dissipation
In this paper the fatigue behaviour of a stainless steel AISI 304L is analysed. In the first part of the work the results obtained under constant amplitude fatigue are presented and synthesised in terms of both stress amplitude and energy released to the surroundings as heat by a unit volume of material per cycle, Q. Then some specimens have been fatigued in variable amplitude, two different load level tests: the first level was set higher while the second was lower than the constant amplitude fatigue limit. The Q values, evaluated during the second part of the fatigue test, have been compared with those calculated under constant amplitude fatigue at the same load level. The comparison allowed us to notice that the Q parameter is sensitive to the fatigue damage accumulated by the material during the first part of the fatigue test
Gram-negative bacterial toe web intertrigo
Gram-negative infection of the toe web space is less frequent than dermatophytes and yeasts, but it is more challenging, especially with the involvement of Pseudomonas aeruginosa in relation to antibiotic resistance and the increased risk of potentially lethal complications. Many conditions, other than infections, might initially present with the same clinical features, recognising the common initial damage (intertrigo), due to skin-on-skin rubbing in a moist environment with air entrapment, which is typical of interdigital spaces. Conditions such as contact eczema, atopic dermatitis, and inverse psoriasis, frequently predispose to, and are maintained by, the intertrigo, triggering a vicious circle. The dermatologist is in a lead position to address the correct assessment and management. A careful screening for predisposing factors is necessary: overweight, diabetic, but also athletes or people attending swimming pools, gyms, public showers/dressing rooms, and thermal baths are also at an increased risk of intertrigo of the toe web spaces. Occupational activities other than recreational might be relevant, such as the use of safety shoes or working in wet warm conditions. Incongruous therapy for tinea pedis or contact dermatitis, frequently auto-prescribed, might be among promoting factors altering the microbial ecosystem balance. The aim of this review is to evaluate
the main epidemiologic and clinical features of Gram-negative bacteria intertrigo, the role of promoting factors, and the measures taken to treat and prevent this disorder. Appropriate treatment and patient education are crucial to prevent further infection and relapses
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