Shape sensing of miniature snake-like robots using optical fibers

Snake like continuum robots are increasingly used for minimally invasive surgery. Most robotic devices of this sort that have been reported to date are controlled in an open loop manner. Using shape sensing to provide closed loop feedback would allow for more accurate control of the robot's position and, hence, more precise surgery. Fiber Bragg Gratings, magnetic sensors and optical reflectance sensors have all been reported for this purpose but are often limited by their cost, size, stiffness or complexity of fabrication. To address this issue, we designed, manufactured and tested a prototype two-link robot with a built-in fiber-optic shape sensor that can deliver and control the position of a CO 2 -laser fiber for soft tissue ablation. The shape sensing is based on optical reflectance, and the device (which has a 4 mm outer diameter) is fabricated using 3D printing. Here we present proof-of-concept results demonstrating successful shape sensing - i.e. measurement of the angular displacement of the upper link of the robot relative to the lower link - in real time with a mean measurement error of only 0.7°

Special Article: Physical Activity, Physical Fitness, and Cardiovascular Risk Factors in Childhood

In adults, physical activity and exercise training are associated with reduced cardiovascular morbidity and mortality, a reduced likelihood of developing adverse cardiovascular risk factors, and improved insulin sensitivity. In childhood, participation in appropriate physical activity may prevent the development of cardiovascular risk factors in the future and complement treatment of existing cardiovascular risk factors, including hypertension, dyslipidemia, and overweight. Exercise in children can also significantly improve insulin sensitivity independent of weight loss. These e fects are mediated in overweight children by increases in lean body mass relative to fat mass and associated improvements in inflammatory mediators, endothelial function, and the associated adverse hormonal milieu

Ultrasonic Measurement of Formability in Thin Ferritic Steel Sheet

The formability of rolled sheet metal is strongly influenced by the texture of the polycrystalline metal. For steel sheet, it is desirable to have high drawability to make automobile body parts, etc. In addition, material homogeneity is desired; that is, material cut from different parts of a rolled sheet should have the same plastic deformation when subjected to deep drawing

Lithium chloride modulates chondrocyte primary cilia and inhibits Hedgehog signaling

This work was supported in part by funding from the AO Foundation (project S-12-15K) and the Medical Research Council (Swindon, United Kingdom) (MR/L002876/1). C.A.P. was supported by the Royal Society of New Zealand through a James Cook Research Fellowshi

Variations on Negative Stain Electron Microscopy Methods: Tools for Tackling Challenging Systems.

Negative stain electron microscopy (EM) allows relatively simple and quick observation of macromolecules and macromolecular complexes through the use of contrast enhancing stain reagent. Although limited in resolution to a maximum of ~18 - 20 Å, negative stain EM is useful for a variety of biological problems and also provides a rapid means of assessing samples for cryo-electron microscopy (cryo-EM). The negative stain workflow is straightforward method; the sample is adsorbed onto a substrate, then a stain is applied, blotted, and dried to produce a thin layer of electron dense stain in which the particles are embedded. Individual samples can, however, behave in markedly different ways under varying staining conditions. This has led to the development of a large variety of substrate preparation techniques, negative staining reagents, and grid washing and blotting techniques. Determining the most appropriate technique for each individual sample must be done on a case-by-case basis and a microscopist must have access to a variety of different techniques to achieve the highest-quality negative stain results. Detailed protocols for two different substrate preparation methods and three different blotting techniques are provided, and an example of a sample that shows markedly different results depending on the method used is shown. In addition, the preparation of some common negative staining reagents, and two novel Lanthanide-based stains, is described with discussion regarding the use of each

Modelling & characterization of a compliant tethered microgripper for microsurgical applications

The development of microscale surgical tools could pave the way for truly minimally invasive microsurgical procedures. This work demonstrates the application of direct laser writing (DLW) using two-photon polymerization (TPP), a rapid prototyping microfabrication technique, to create a tethered, passively actuated three-dimensional gripper with potential applications in microbiopsy. A microgripper design was devised, modelled and optimized. The gripper was then fabricated and characterized for validation of the theoretical model. The results demonstrate that modelling the behavior of compliant microtools provides a useful approximation for the observed trends and, thus, can be utilized in the design of TPP tools. Future work on the incorporation of viscoelastic material into the model will further improve agreement between the predicted and experimental performance

IRLANDA. Mapas generales (17). 1:800000

Dedicatoria : "To the Most-High Puissant Prince William Fitzgerald Duke of Leinster ... This Map is most gratefully inscribed by his Grace's most humble & most obedient Servant Charles O'Conor Esqre"Escala hallada a partir de un grado de latitud [= 13,8 cm]. Coordenadas referidas al meridiano de Londres (O 11°15'--O 4°25'/N 55°25'--N 51°55'). Red geográfica de 1° en 1°Destaca los límites entre las provincias y condados de la islaTítulo enmarcado en cartela, acompañada de una figura femenina y decorada con un blasón, en el que se inscribe la leyenda : "Crom a Boo

Rehabilitating mangrove ecosystem services: a case study on the relative benefits of abandoned pond reversion from Panay Island, Philippines

Mangroves provide vital climate change mitigation and adaptation (CCMA) ecosystem services (ES), yet have suffered extensive tropics-wide declines. To mitigate losses, rehabilitation is high on the conservation agenda. However, the relative functionality and ES delivery of rehabilitated mangroves in different intertidal locations is rarely assessed. In a case study from Panay Island, Philippines, using field- and satellite-derived methods, we assess carbon stocks and coastal protection potential of rehabilitated low-intertidal seafront and mid- to upper-intertidal abandoned (leased) fishpond areas, against reference natural mangroves. Due to large sizes and appropriate site conditions, targeted abandoned fishpond reversion to former mangrove was found to be favourable for enhancing CCMA in the coastal zone. In a municipality-specific case study, 96.7% of abandoned fishponds with high potential for effective greenbelt rehabilitation had favourable tenure status for reversion. These findings have implications for coastal zone management in Asia in the face of climate change

Magnetic and multiferroic properties of dilute Fe-doped BaTiO3 crystals

Combining and coupling both magnetic and electric properties in one single phase multiferroic material has attracted high interest recently to enable a broad range of novel devices and applications. To evaluate one potential route toward new multiferroics, we have studied 0.5% Fe-doped BaTiO3 single crystals and measured the ferroelectric, magnetic, and multiferroic properties. X-ray absorption spectroscopy shows the presence of Fe3+, and magnetic measurements confirmed that this has a significant impact on the magnetic properties. Doping of iron introduces paramagnetism from lone iron atoms as well as what appears to be a weak ferromagnetism. Multiferroicity and magnetoelectric (ME) coupling were observed in the polarization-electric field hysteresis loops with an applied magnetic field, yet there was no direct evidence that ME coupling persists when the sample was in the defect dipole-aligned state

Spatial variability and changes of metabolite concentrations in the cortico-spinal tract in multiple sclerosis using coronal CSI

We characterized metabolic changes along the cortico-spinal tract (CST) in multiple sclerosis (MS) patients using a novel application of chemical shift imaging (CSI) and considering the spatial variation of metabolite levels. Thirteen relapsing-remitting (RR) and 13 primary-progressive (PP) MS patients and 16 controls underwent (1)H-MR CSI, which was applied to coronal-oblique scans to sample the entire CST. The concentrations of the main metabolites, i.e., N-acetyl-aspartate, myo-Inositol (Ins), choline containing compounds (Cho) and creatine and phosphocreatine (Cr), were calculated within voxels placed in regions where the CST is located, from cerebral peduncle to corona radiata. Differences in metabolite concentrations between groups and associations between metabolite concentrations and disability were investigated, allowing for the spatial variability of metabolite concentrations in the statistical model. RRMS patients showed higher CST Cho concentration than controls, and higher CST Ins concentration than PPMS, suggesting greater inflammation and glial proliferation in the RR than in the PP course. In RRMS, a significant, albeit modest, association between greater Ins concentration and greater disability suggested that gliosis may be relevant to disability. In PPMS, lower CST Cho and Cr concentrations correlated with greater disability, suggesting that in the progressive stage of the disease, inflammation declines and energy metabolism reduces. Attention to the spatial variation of metabolite concentrations made it possible to detect in patients a greater increase in Cr concentration towards the superior voxels as compared to controls and a stronger association between Cho and disability, suggesting that this step improves our ability to identify clinically relevant metabolic changes