682 research outputs found
Shaking-induced dynamics of cold atoms in magnetic traps
We describe an experiment in which cold rubidium atoms, confined in an elongated magnetic trap, are excited
by transverse oscillation of the trap center. The temperature after excitation exhibits resonance as a function of
the driving frequency. We measure these resonances at several different trap frequencies. In order to interpret the
experiments, we develop a simple model that incorporates both collisions between atoms and the anharmonicity
of the real three-dimensional trapping potential. As well as providing a precise connection between the transverse
harmonic oscillation frequency and the temperature resonance frequency, this model gives insight into the heating
and loss mechanisms and into the dynamics of driven clouds of cold trapped atoms
Methylated DNA recognition during the reversal of epigenetic silencing is regulated by cysteine and cerine residues in the Epstein-Barr Virus lytic switch protein
Epstein-Barr virus (EBV) causes infectious mononucleosis and is associated with various malignancies, including Burkitt's lymphoma and nasopharyngeal carcinoma. Like all herpesviruses, the EBV life cycle alternates between latency and lytic replication. During latency, the viral genome is largely silenced by host-driven methylation of CpG motifs and, in the switch to the lytic cycle, this epigenetic silencing is overturned. A key event is the activation of the viral BRLF1 gene by the immediate-early protein Zta. Zta is a bZIP transcription factor that preferentially binds to specific response elements (ZREs) in the BRLF1 promoter (Rp) when these elements are methylated. Zta's ability to trigger lytic cycle activation is severely compromised when a cysteine residue in its bZIP domain is mutated to serine (C189S), but the molecular basis for this effect is unknown. Here we show that the C189S mutant is defective for activating Rp in a Burkitt's lymphoma cell line. The mutant is compromised both in vitro and in vivo for binding two methylated ZREs in Rp (ZRE2 and ZRE3), although the effect is striking only for ZRE3. Molecular modeling of Zta bound to methylated ZRE3, together with biochemical data, indicate that C189 directly contacts one of the two methyl cytosines within a specific CpG motif. The motif's second methyl cytosine (on the complementary DNA strand) is predicted to contact S186, a residue known to regulate methyl-ZRE recognition. Our results suggest that C189 regulates the enhanced interaction of Zta with methylated DNA in overturning the epigenetic control of viral latency. As C189 is conserved in many bZIP proteins, the selectivity of Zta for methylated DNA may be a paradigm for a more general phenomenon
Protocol for the saMS trial (supportive adjustment for multiple sclerosis): a randomized controlled trial comparing cognitive behavioral therapy to supportive listening for adjustment to multiple sclerosis
BackgroundMultiple Sclerosis (MS) is an incurable, chronic, potentially progressive and unpredictable disease of the central nervous system. The disease produces a range of unpleasant and debilitating symptoms, which can have a profound impact including disrupting activities of daily living, employment, income, relationships, social and leisure activities, and life goals. Adjusting to the illness is therefore particularly challenging. This trial tests the effectiveness of a cognitive behavioural intervention compared to supportive listening to assist adjustment in the early stages of MS.MethodsThis is a two arm randomized multi-centre parallel group controlled trial. 122 consenting participants who meet eligibility criteria will be randomly allocated to receive either Cognitive Behavioral Therapy or Supportive Listening. Eight one hour sessions of therapy (delivered over a period of 10 weeks) will be delivered by general nurses trained in both treatments. Self-report questionnaire data will be collected at baseline (0 weeks), mid-therapy (week 5 of therapy), post-therapy (15 weeks) and at six months (26 weeks) and twelve months (52 weeks) follow-up. Primary outcomes are distress and MS-related social and role impairment at twelve month follow-up. Analysis will also consider predictors and mechanisms of change during therapy. In-depth interviews to examine participants’ experiences of the interventions will be conducted with a purposively sampled sub-set of the trial participants. An economic analysis will also take place. DiscussionThis trial is distinctive in its aims in that it aids adjustment to MS in a broad sense. It is not a treatment specifically for depression. Use of nurses as therapists makes the interventions potentially viable in terms of being rolled out in the NHS. The trial benefits from incorporating patient input in the development and evaluation stages. The trial will provide important information about the efficacy, cost-effectiveness and acceptability of the interventions as well as mechanisms of psychosocial adjustment.Trial registrationCurrent Controlled Trials ISRCTN91377356<br/
Implementation of a suite of components for Software Defined Radio using an SCA-compliant framework
The aim of this work is to introduce Software Defined Radio (SDR) technology, present an open source SCA-compliant framework whose name is Redhawk, which derives from the OSSIE project and describes an implementation example of some processing instances.
Since in SDR applications it is necessary to run the same software on different hardware, portability becomes the main important aspect in the development of software radio applica- tions. The use of a SCA-compliant framework solves this issue making hardware transparent to the programmer and reducing time and costs of code development.
This aspect can be exploited for prototyping applications quickly without the need of a spe- cific hardware or testing new standards and protocols.
We will introduce some basic concepts of SDR, of the SCA architecture, based on CORBA, and Redhawk. We will then talk about of the implementation of a suite of components, writ- ten by using Redhawk IDE and C++ programming language. These will be tied together to form an application called waveform.
We will also present the results obtained by enforcing a certain level of parallelism in our algorithm to speed up computation in Redhawk components and boost performances against a more simpler non concurrent implementation of the same algorithms
Loss of functional pRB is not a ubiquitous feature of B-cell malignancies
Human cancers frequently sustain genetic mutations that alter the function of their G1 cell cycle control check point. These include changes to the retinoblastoma gene and to the genes that regulate its phosphorylation, such as the cyclin-dependent kinase inhibitor p16(INK4a). Altered expression of retinoblastoma protein (pRb) is associated with non-Hodgkin's lymphoma, particularly centroblastic and Burkitt's lymphomas. pRb is expressed in normal B-cells and its regulatory phosphorylation pathway is activated in response to a variety of stimuli. Since human B-lymphoma-derived cell lines are often used as in vitro model systems to analyse the downstream effects of signal transduction, we examined the functional status of pRb in a panel of human B-cell lines. We identified eleven cell lines which express the hyperphosphorylated forms of pRb. Furthermore, we suggest that the pRb protein appears to be functional in these cell lines
Somatotopic map and inter- and intra-digit distance in Brodmann area 2 by pressure stimulation
The somatotopic representation of the tactile stimulation on the finger in the brain is an essential part of understanding the human somatosensory system as well as rehabilitation and other clinical therapies. Many studies have used vibrotactile stimulations and reported finger somatotopic representations in the Brodmann area 3 (BA 3). On the contrary, few studies investigated finger somatotopic representation using pressure stimulations. Therefore, the present study aimed to find a comprehensive somatotopic representation (somatotopic map and inter- and intra-digit distance) within BA 2 of humans that could describe tactile stimulations on different joints across the fingers by applying pressure stimulation to three joints-the first (p1), second (p2), and third (p3) joints-of four fingers (index, middle, ring, and little finger). Significant differences were observed in the inter-digit distance between the first joints (p1) of the index and little fingers, and between the third joints (p3) of the index and little fingers. In addition, a significant difference was observed in the intra-digit distance between p1 and p3 of the little finger. This study suggests that a somatotopic map and inter- and intra-digit distance could be found in BA 2 in response to pressure stimulation on finger joints.ope
Clinical and histological challenge in the differential diagnosis of diffuse alopecia: female androgenetic alopecia, telogen effluvium and alopecia areata - part I
Differences in consumer use of food labels by weight loss strategies and demographic characteristics
Data privacy compliance benefits for organisations - a cyber-physical systems and Internet of Things study
The protection of people’s privacy is both a legal requirement and a key factor for doing business in many jurisdictions. Organisations thus have a legal obligation to get their privacy compliance in order as a matter of business importance. This applies not only to organisations’ day-to-day business operations, but also to the information technology systems they use, develop or deploy. However, privacy compliance, like any other legal compliance requirements, is often seen as an extra burden that is both unnecessary and costly. Such a view of compliance can result in negative consequences and lost opportunities for organisations. This paper seeks to position data privacy compliance as a value proposition for organisations by focusing on the benefits that can be derived from data privacy compliance as it applies to a particular subset of information technology systems, namely cyber-physical systems and Internet of Things technologies. A baseline list of data privacy compliance benefits, contextualised for CPSs and IoT with the South African legal landscape is proposed.http://www.springer.comseries/7899hj2021Informatic
Earliest evidence for the ivory trade in southern Africa : isotopic and ZooMS analysis of seventh-tenth century AD ivory from KwaZulu-Natal
KwaGandaganda, Ndondondwane and Wosi were major Early Farming Community settlements in what is today the KwaZulu-Natal province of South Africa. These sites have yielded, among other remains, abundant evidence of ivory and ivory working dating to the seventh–tenth centuries ad, pre-dating by approximately 200 years the better-known ivory artefacts from sites in the Limpopo River Valley and surrounding regions. We report the results of carbon, nitrogen and strontium isotope analysis to explore the origins and procurement of this ivory, in combination with Zooarchaeology by Mass Spectrometry (ZooMS) to identify the species of animals from which it was derived. All of the ivory studied using ZooMS was elephant, despite the presence of hippopotamus remains on all three sites. Some ivory was probably obtained from elephant herds that lived close to the sites, in the densely wooded river valleys favoured by both elephants and early farmers. Other material came from savannah environments further afield. Ivory found at these three sites was drawn from different catchments, implying a degree of landscape/resource partitioning even at this early stage. These communities clearly invested substantial effort in obtaining ivory from across the region, which speaks to the importance of this commodity in the economy of the time. We suggest that some ivory items were for local use, but that some may have been intended for more distant markets via Indian Ocean trade
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