Three-dimensional localization and optical imaging of objects in turbid media with independent component analysis

A new approach for optical imaging and localization of objects in turbid media that makes use of the independent component analysis (ICA) from information theory is demonstrated. Experimental arrangement realizes a multisource illumination of a turbid medium with embedded objects and a multidetector acquisition of transmitted light on the medium boundary. The resulting spatial diversity and multiple angular observations provide robust data for three-dimensional localization and characterization of absorbing and scattering inhomogeneities embedded in a turbid medium. ICA of the perturbations in the spatial intensity distribution on the medium boundary sorts out the embedded objects, and their locations are obtained from Green\u27s function analysis based on any appropriate light propagation model. Imaging experiments were carried out on two highly scattering samples of thickness approximately 50 times the transport mean-free path of the respective medium. One turbid medium had two embedded absorptive objects, and the other had four scattering objects. An independent component separation of the signal, in conjunction with diffusive photon migration theory, was used to locate the embedded inhomogeneities. In both cases, improved lateral and axial localizations of the objects over the result obtained by use of common photon migration reconstruction algorithms were achieved. The approach is applicable to different medium geometries, can be used with any suitable photon propagation model, and is amenable to near-real-time imaging applications

Avoiding Lock Outs: Proactive FIDO Account Recovery using Managerless Group Signatures

Passwords are difficult to remember, easy to guess and prone to hacking. While there have been several attempts to solve the aforementioned problems commonly associated with passwords, one of the most successful ones to date has been by the Fast Identity Online (FIDO) alliance. FIDO introduced a series of protocols that combine local authentication on a user device with remote validation on relying party servers using public-key cryptography. One of the fundamental problems of FIDO protocols is complete reliance on a single user device for authentication. More specifically, the private key used for signing relying party challenges can only be stored on a single device. Each FIDO authenticator key is linked uniquely to an account with a relying party service. As a result a lost or stolen user device necessitates creation of new user account, using a new device, with each (previously enrolled) relying party service. To overcome this limitation, we introduce a dynamic managerless group signature scheme that organizes authenticators into groups. Each authenticator in a group has a unique private key that links it to an account with a relying party, which can sign relying party challenges. The relying party server has a group verification key that can validate challenges signed using the private key of any authenticator in a group. Our approach provides additional redundancy and usability to the FIDO protocol whilst still achieving the security properties expected in the FIDO setting such as unforgeability and unlinkability

Nuclear Magnetic Resonance

Contains research objectives and reports on five research projects

Walking and the social life of solar charging in rural Africa

We consider practices that sustain social and physical environments beyond those dominating sustainable HCI discourse. We describe links between walking, sociality, and using resources in a case study of community-based, solar, cellphone charging in villages in South Africa’s Eastern Cape. Like 360 million rural Africans, inhabitants of these villages are poor and, like 25% and 92% of the world, respectively, do not have domestic electricity or own motor vehicles. We describe nine practices in using the charging stations we deployed. We recorded 700 people using the stations, over a year, some regularly. We suggest that the way we frame practices limits insights about them, and consider various routines in using and sharing local resources to discover relations that might also feature in charging. Specifically, walking interconnects routines in using, storing, sharing and sustaining resources, and contributes to knowing, feeling, wanting and avoiding as well as to different aspects of sociality, social order and perspectives on sustainability. Along the way, bodies acquire literacies that make certain relationalities legible. Our study shows we cannot assert what sustainable practice means a priori and, further, that detaching practices from bodies and their paths limits solutions, at least in rural Africa. Thus, we advocate a more “alongly” integrated approach to data about practices.This research was supported by CSIR-Meraka, South Africa and, partly, by an Engineering and Physical Sciences Research Council grant (EP/H042857/1).http://dl.acm.org/hb201

Walking and the Social Life of Solar Charging in Rural Africa

We illustrate links between walking, sociality and using resources in a case-study of community-based, solar, cellphone charging in two villages in Eastern Cape, South Africa. Like 360 million rural Sub-saharan Africans, inhabitants are poor and, like 25% and 92%, of the world respectively, do not have domestic electricity or own motor vehicles. We show that the ways we move through the world affect the meanings we embody; that certain representations obscure continuities in the practices we seek to understand and influence; and, some of the motivations of the billions of people who are marginalized in discussing sustainable HCI. Locally, about 65% of inhabitants over 14 years old own cell- phones and, over a year, we recorded 500 names of people using the Charging Stations that, we deployed within several technology probing endeavours, many on a regular basis. The detail of our longitudinal study contributes considerably to sustainable design for ‘developing’ regions. Walking is a noticeable part of charging, and all other subsistence rou- tines, and shapes inhabitants’ motivations when they use, re-purpose, store and share resources. Inhabitants are moti- vated by cost and comfort and, importantly, by performing collectivity in their tight-knit community; but, not by being green. Further, different ways of walking relate to social roles and other aspects of sociality and, we propose, shaped inhabitants’ and researchers’ perspectives on charging and using phones. We suggest this is significant for the methods and designs that we use to explore and support sustainable practices in rural Africa and, indeed, more generally

Systematic screening for skin, hair, and nail abnormalities in a large-scale knockout mouse program

The International Knockout Mouse Consortium was formed in 2007 to inactivate (“knockout”) all protein-coding genes in the mouse genome in embryonic stem cells. Production and characterization of these mice, now underway, has generated and phenotyped 3,100 strains with knockout alleles. Skin and adnexa diseases are best defined at the gross clinical level and by histopathology. Representative retired breeders had skin collected from the back, abdomen, eyelids, muzzle, ears, tail, and lower limbs including the nails. To date, 169 novel mutant lines were reviewed and of these, only one was found to have a relatively minor sebaceous gland abnormality associated with follicular dystrophy. The B6N(Cg)-Far2tm2b(KOMP)Wtsi/2J strain, had lesions affecting sebaceous glands with what appeared to be a secondary follicular dystrophy. A second line, B6N(Cg)-Ppp1r9btm1.1(KOMP)Vlcg/J, had follicular dystrophy limited to many but not all mystacial vibrissae in heterozygous but not homozygous mutant mice, suggesting that this was a nonspecific background lesion. We discuss potential reasons for the low frequency of skin and adnexal phenotypes in mice from this project in comparison to those seen in human Mendelian diseases, and suggest alternative approaches to identification of human disease-relevant models.This work was supported by grants from the National Institutes of Health (R21-AR063781 and U42-OD011185). Shared services at The Jackson Laboratory are subsidized by a National Cancer Institute Core Grant (P30-CA034196). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

THE EFFECT OF ASTAXANTHIN ON THE PREVENTION OF COGNITIVE DECREMENTS FOLLOWING A MENTAL FATIGUE PROTOCOL

BACKGROUND: Astaxanthin (AX) is a carotenoid found in marine species and is a popular dietary supplement due to its unique ability to cross the blood-brain barrier. It appears that AX may preserve aspects of cognition during periods of cerebral stress (such as cognitive fatigue or in the development of neurodegeneration), provided AX’s ability to support and maintain mitochondria function, specifically within the brain. Therefore, the purpose of this study is to examine the effect AX has on markers of cognitive performance following a mental fatiguing protocol in recreationally active females. METHODS: Participants will include 30 recreationally active females (18-39 years) and will utilize a double-blinded, between-design, with participants reporting to the laboratory on four separate occasions. All trials will consist of a battery of baseline and post-mental fatigue cognitive assessments (psychomotor vigilance test (PVT), task switching, incongruent flanker). Additionally, either a battery of mentally fatiguing tasks (color multi-source interference task (CMSIT), Rapid visual information processing task (RVIP), time load dual back task (TLDB)), or a time-matched control will be utilized in between pre and post-testing. Following trial 2, participants will be randomly assigned to ingest either AX (12 mg/day-1) or a matched placebo for 6-weeks prior to reporting back to the laboratory for repeat post-testing. ANTICIPATED RESULTS: It is hypothesized AX will mitigate decrements to cognitive performance following mental fatigue in recreationally active females. Funding: This study is funded by AstaReal USA

Astaxanthin Supplementation Reduces Subjective Markers of Muscle Soreness following Eccentric Exercise in Resistance-Trained Men

Strenuous exercise involving eccentric muscle actions induces skeletal muscle damage resulting in delayed onset muscle soreness (DOMS). Antioxidant supplementation, such as astaxanthin (AX), may alleviate muscle injury following intense exercise. The purpose of this study was to investigate the effect of a four-week course of AX supplementation at 12 mg/day−1 on subjective markers of DOMS, recovery, and performance after a bout of muscle damaging eccentric exercise. Nineteen resistance-trained men (mean ± SD: age, 22.6 ± 2.2 y) completed a between-group design with a four-week supplementation period of 12 mg/day−1 of either AX or a placebo. Subjects completed four trials, with trials One and Three designed to induce muscle damage, consisting of a one repetition maximum test (1RM) for leg-press, followed by five sets of ten repetitions at 65% of 1RM. Trials Two and Four were performance trials, conducted 48 h later and consisting of repetitions to failure at 65%, 70%, and 75% of 1RM. Subjective markers of DOMS and recovery were collected at multiple timepoints post-trial for trials One and Three. Although performance was not affected (p > 0.05), AX supplementation significantly decreased subjective markers of DOMS (p = 0.01) compared to the placebo. The results demonstrated that AX may enhance recovery by reducing DOMS without detriment to performance in resistance-trained men