Bio-Artificial Synergies for Grasp Posture Control of Supernumerary Robotic Fingers

A new type of wrist-mounted robot, the Supernumerary Robotic (SR) Fingers, is proposed to work closely with the human hand and aid the human in performing a variety of prehensile tasks. For people with diminished functionality of their hands, these robotic fingers could provide the opportunity to live with more independence and work more productively. A natural and implicit coordination between the SR Fingers and the human fingers is required so the robot can be transformed to act as part of the human body. This paper presents a novel control algorithm, termed “Bio-Artificial Synergies”, which enables the SR and human fingers to share the task load together and adapt to diverse task conditions. Through grasp experiments and data analysis, postural synergies were found for a seven-fingered hand comprised of two SR Fingers and five human fingers. The synergy-based control law was then extracted from the experimental data using Partial Least Squares (PLS) regression and tested on the SR Finger prototype as a proof of concept

Multi-probe robotic positioner for cryoablation in MRI

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 116-118).This thesis describes the design of a guidance device for faster and more accurate targeting of multiple probes during cryoablation and other percutaneous interventions performed in closed bore magnetic resonance (MR) imaging systems. The device is intended to be mounted onto a Siemens 110 mm MR loop coil that rests on the patient and contains a cable driven two-degree-of- freedom spherical mechanism that orientates the intervention probes about a remote center of motion located 15 mm above the skin entry point. A carriage, pulled by strong and low stretch cables, can position up to three intervention probes as it travels on a rotating hoop. Its motion is constrained by a custom designed roller bearing to minimize friction. A thumbscrew fastened latch allows a probe to be engaged in a guide that constrains the probe along a specific trajectory. The probe can also be disengaged from its track, freeing it to move with respiration and enabling the guide to be repositioned for another probe to be inserted. Compact MR compatible piezoelectric motors are used to actuate the system. A prototype was built from 3D printed ABS plastic as a proof of concept. Bench level evaluation demonstrated that each component of the device performs according to the design specifications. The device performance was characterized by analyzing still images taken before and after movement, which yielded sub-degree accuracy, sub-degree repeatability near vertical position, and an incremental step resolution of at least 0.5 degree. Upon further developments of the registration and calibration modules in 3D slicer to interface the robot with image data, evaluation of the device in MRI will be performed.by Faye Y. Wu.S.M

Supernumerary Robotic Fingers as a Therapeutic Device for Hemiparetic Patients

Patients with hemiparesis often have limited functionality in the left or right hand. The standard therapeutic approach requires the patient to attempt to make use of the weak hand even though it is not functionally capable, which can result in feelings of frustration. Furthermore, hemiparetic patients also face challenges in completing many bimanual tasks, for example walker manipulation, that are critical to patients’ independence and quality of life. A prototype therapeutic device with two supernumerary robotic fingers was used to determine if robotic fingers could functionally assist a human in the performance of bimanual tasks by observing the pose of the healthy hand. Specific focus was placed on the identification of a straightforward control routine which would allow a patient to carry out simple manipulation tasks with some intermittent input from a therapist. Part of this routine involved allowing a patient to switch between active and inactive monitoring of hand position, resulting in additional manipulation capabilities. The prototype successfully enabled a test subject to complete various bimanual tasks using the robotic fingers in place of normal hand motions. From these results, it is clear that the device could allow a hemiparetic patient to complete tasks which would previously have been impossible to perform

Functional Characteristics of a Highly Specific Integrase Encoded by an LTR-Retrotransposon

Background: The retroviral Integrase protein catalyzes the insertion of linear viral DNA into host cell DNA. Although different retroviruses have been shown to target distinctive chromosomal regions, few of them display a site-specific integration. ZAM, a retroelement from Drosophila melanogaster very similar in structure and replication cycle to mammalian retroviruses is highly site-specific. Indeed, ZAM copies target the genomic 59-CGCGCg-39 consensus-sequences. To enlighten the determinants of this high integration specificity, we investigated the functional properties of its integrase protein denoted ZAM-IN. Principal Findings: Here we show that ZAM-IN displays the property to nick DNA molecules in vitro. This endonuclease activity targets specific sequences that are present in a 388 bp fragment taken from the white locus and known to be a genomic ZAM integration site in vivo. Furthermore, ZAM-IN displays the unusual property to directly bind specific genomic DNA sequences. Two specific and independent sites are recognized within the 388 bp fragment of the white locus: the CGCGCg sequence and a closely apposed site different in sequence. Conclusion: This study strongly argues that the intrinsic properties of ZAM-IN, ie its binding properties and its endonuclease activity, play an important part in ZAM integration specificity. Its ability to select two binding sites and to nick the DNA molecule reminds the strategy used by some site-specific recombination enzymes and forms the basis for site-specifi

Interiorized Feminism and Gendered Nostalgia of The ‘Daughter Generation’ in Ning Ying's Perpetual Motion

This is the author's accepted manuscript. The original publication is available at http://dx.doi.org/10.1386/jcc.5.3.253_1Ning Ying’s 2006 film Wuqiong dong/Perpetual Motion can be regarded as her first attempt to explore the genre of ‘women’s film’. Deviating from her previous neo-realist style, this film seeks to cultivate an alternative cinematic practice through developing a heavy-handed negative aesthetics. Ning Ying interiorizes the filmic exploration of female subjectivity in an enclosed time and space, which is constantly haunted by a spectral aesthetics characterized by audio-visual allusions to loss, grave, ruins and ghosts. However, the film’s radical content and alternative aesthetics are, ironically, packaged in prevailing consumer aesthetics and commodity fetishism on and off the silver screen. All these competing drives and accounts render the film a contested narrative constantly oscillating between avant-garde feminism and domestic melodrama, and between a register of disintegrating sisterhood and a celebrity scandal of adultery. This article examines the discursive and aesthetic innovations, contradictions and limits of Ning Ying’s cinematic feminism

The promoter of ZmMRP-1, a maize transfer cell-specific transcriptional activator, is induced at solute exchange surfaces and responds to transport demands

Transfer cells have specializations that facilitate the transport of solutes across plant exchange surfaces. ZmMRP-1 is a maize (Zea mays) endosperm transfer cell-specific transcriptional activator that plays a central role in the regulatory pathways controlling transfer cell differentiation and function. The present work investigates the signals controlling the expression of ZmMRP-1 through the production of transgenic lines of maize, Arabidopsis, tobacco and barley containing ZmMRP-1promoter:GUS reporter constructs. The GUS signal predominantly appeared in regions of active transport between source and sink tissues, including nematode-induced feeding structures and at sites of vascular connection between developing organs and the main plant vasculature. In those cases, promoter induction was associated with the initial developmental stages of transport structures. Significantly, transfer cells also differentiated in these regions suggesting that, independent of species, location or morphological features, transfer cells might differentiate in a similar way under the influence of conserved induction signals. In planta and yeast experiments showed that the promoter activity is modulated by carbohydrates, glucose being the most effective inducer

Illustrating and homology modeling the proteins of the Zika virus

The Zika virus (ZIKV) is a flavivirus of the family Flaviviridae, which is similar to dengue virus, yellow fever and West Nile virus. Recent outbreaks in South America, Latin America, the Caribbean and in particular Brazil have led to concern for the spread of the disease and potential to cause Guillain-Barré syndrome and microcephaly. Although ZIKV has been known of for over 60 years there is very little in the way of knowledge of the virus with few publications and no crystal structures. No antivirals have been tested against it either in vitro or in vivo. ZIKV therefore epitomizes a neglected disease. Several suggested steps have been proposed which could be taken to initiate ZIKV antiviral drug discovery using both high throughput screens as well as structure-based design based on homology models for the key proteins. We now describe preliminary homology models created for NS5, FtsJ, NS4B, NS4A, HELICc, DEXDc, peptidase S7, NS2B, NS2A, NS1, E stem, glycoprotein M, propeptide, capsid and glycoprotein E using SWISS-MODEL. Eleven out of 15 models pass our model quality criteria for their further use. While a ZIKV glycoprotein E homology model was initially described in the immature conformation as a trimer, we now describe the mature dimer conformer which allowed the construction of an illustration of the complete virion. By comparing illustrations of ZIKV based on this new homology model and the dengue virus crystal structure we propose potential differences that could be exploited for antiviral and vaccine design. The prediction of sites for glycosylation on this protein may also be useful in this regard. While we await a cryo-EM structure of ZIKV and eventual crystal structures of the individual proteins, these homology models provide the community with a starting point for structure-based design of drugs and vaccines as well as a for computational virtual screening

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Establishment and cryptic transmission of Zika virus in Brazil and the Americas

Transmission of Zika virus (ZIKV) in the Americas was first confirmed in May 2015 in northeast Brazil1. Brazil has had the highest number of reported ZIKV cases worldwide (more than 200,000 by 24 December 20162) and the most cases associated with microcephaly and other birth defects (2,366 confirmed by 31 December 20162). Since the initial detection of ZIKV in Brazil, more than 45 countries in the Americas have reported local ZIKV transmission, with 24 of these reporting severe ZIKV-associated disease3. However, the origin and epidemic history of ZIKV in Brazil and the Americas remain poorly understood, despite the value of this information for interpreting observed trends in reported microcephaly. Here we address this issue by generating 54 complete or partial ZIKV genomes, mostly from Brazil, and reporting data generated by a mobile genomics laboratory that travelled across northeast Brazil in 2016. One sequence represents the earliest confirmed ZIKV infection in Brazil. Analyses of viral genomes with ecological and epidemiological data yield an estimate that ZIKV was present in northeast Brazil by February 2014 and is likely to have disseminated from there, nationally and internationally, before the first detection of ZIKV in the Americas. Estimated dates for the international spread of ZIKV from Brazil indicate the duration of pre-detection cryptic transmission in recipient regions. The role of northeast Brazil in the establishment of ZIKV in the Americas is further supported by geographic analysis of ZIKV transmission potential and by estimates of the basic reproduction number of the virus