17,286 research outputs found

    Rotational modulation of the linear polarimetric variability of the cool dwarf TVLM 513−-46546

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    Aims: We aimed to monitor the optical linear polarimetric signal of the magnetized, rapidly rotating M8.5 dwarf TVLM 513−-46546. Methods: RR- and II-band linear polarimetry images were collected with the ALFOSC instrument of the 2.56-m Nordic Optical Telescope on two consecutive nights covering about 0.5 and 4 rotation cycles in the RR and II filters, respectively. We also obtained simultaneous intensity curves by means of differential photometry. The typical precision of the data is ±\pm0.46\% (RR), ±\pm0.35\% (II) in the linear polarization degree and ±\pm9 mmag (RR), ±\pm1.6 mmag (II) in the differential intensity curves. Results: Strong and variable linear polarization is detected in the RR and II filters, with values of maximum polarization (p∗p^{*} = 1.30±\pm0.35 \%) similar for both bands. The intensity and the polarimetric curves present a sinusoid-like pattern with a periodicity of ∌\sim1.98 h, which we ascribe to structures in TVLM 513−-46's surface synchronized with rotation. We found that the peaks of the intensity and polarimetric curves occur with a phase difference of 0.18±\pm0.01, and that the maximum of the linear polarization happens nearly half a period (0.59±\pm0.03) after the radio pulse. We discussed different scenarios to account for the observed properties of the light curves.Comment: Accepted for publication in Astronomy and Astrophysic

    Simultaneous optical and near-infrared linear spectropolarimetry of the earthshine

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    Aims: We aim to extend our current observational understanding of the integrated planet Earth spectropolarimetry from the optical to the near-infrared wavelengths. Major biomarkers like O2_{\rm 2} and water vapor are strong flux absorbents in the Earth atmosphere and some linear polarization of the reflected stellar light is expected to occur at these wavelengths. Methods: Simultaneous optical (0.4−0.90.4-0.9 ÎŒ\mum) and near-infrared (0.9−2.30.9-2.3 ÎŒ\mum) linear spectropolarimetric data of the earthshine were acquired by observing the nightside of the waxing Moon. The data have sufficient spectral resolution (2.51 nm in the optical, and 1.83 and 2.91 nm in the near-infrared) to resolve major molecular species present in the Earth atmosphere. Results: We find the highest values of linear polarization (≄10%\ge 10\%) at the bluest wavelengths, which agrees with the literature. Linear polarization intensity steadily decreases towards red wavelengths reaching a nearly flat value beyond ∌\sim0.8 ÎŒ\mum. In the near-infrared, we measured a polarization degree of ∌4.5%\sim4.5 \% for the continuum. We report the detection of molecular features due to O2_{2} at 0.760,1.25ÎŒ0.760, 1.25 \mum and H2_{2}O at 0.653−-0.725 ÎŒ\mum, 0.780−-0.825 ÎŒ\mum, 0.93 and 1.12 ÎŒ\mum in the spectropolarimetric data; most of them show high linear polarimetry degrees above the continuum. In particular, the broad H2_{2}O 1.12 ÎŒ\mum band displays a polarimetric intensity as high as that of the blue optical. These features may become a powerful tool to characterize Earth-like planets in polarized light.Comment: 4 pages, 3 figures. Accepted for publication as Letter in Astronomy and Astrophysics on 23/01/201

    Testing the existence of optical linear polarization in young brown dwarfs

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    Linear polarization can be used as a probe of the existence of atmospheric condensates in ultracool dwarfs. Models predict that the observed linear polarization increases withthe degree of oblateness, which is inversely proportional to the surface gravity. We aimed to test the existence of optical linear polarization in a sample of bright young brown dwarfs, with spectral types between M6 and L2, observable from the Calar Alto Observatory, and cataloged previously as low gravity objects using spectroscopy. Linear polarimetric images were collected in I and R-band using CAFOS at the 2.2 m telescope in Calar Alto Observatory (Spain). The flux ratio method was employed to determine the linear polarization degrees. With a confidence of 3σ\sigma, our data indicate that all targets have a linear polarimetry degree in average below 0.69% in the I-band, and below 1.0% in the R-band, at the time they were observed. We detected significant (i.e. P/σ\sigma ≀\le 3) linear polarization for the young M6 dwarf 2MASS J04221413+1530525 in the R-band, with a degree of p∗\mathrm{p^{*}} = 0.81 ±\pm 0.17 %.Comment: Accepted for publication in MNRA

    Total syntheses of conformationally-locked difluorinated pentopyranose analogues and a pentopyranosyl phosphate mimetic

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    Trifluoroethanol has been elaborated, via a telescoped sequence involving a metalated difluoroenol, a difluoroallylic alcohol, [2,3]-Wittig rearrangement, and ultimately an RCM reaction and requiring minimal intermediate purification, to a number of cyclooctenone intermediates. Epoxidation of these intermediates followed by transannular ring opening or dihydroxylation, then transannular hemiacetalization delivers novel bicyclic analogues of pentopyranoses, which were elaborated (in one case) to an analogue of a glycosyl phosphate

    Trigonometric parallaxes of young field L dwarfs

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    (Abridged) We aim to determine the trigonometric parallaxes and proper motions of a sample of ten field L0-L5 dwarfs with spectroscopic evidence for low-gravity atmospheres. We obtained J and Ks imaging data using 2-4-m class telescopes with a typical cadence of one image per month between 2010 January and 2012 December. We also obtained low resolution optical spectra (R~300, 500-1100 nm) using the 10-m GTCs to assess the presence of lithium absorption in four targets and confirm their young age. Trigonometric parallaxes and proper motions were derived to typical accuracies of 1 mas and +/-10 mas/yr. All ten L dwarfs have large motions, and are located at distances between 9 and 47 pc. They lie above and on the sequence of field dwarfs in the absolute J and K_s magnitude versus spectral type and luminosity versus Teff diagrams, implying ages similar to or smaller than those typical of the field. The detection of atomic lithium in the atmosphere of 2MASS J00452143+1634446 is reported for the first time. Three dwarfs have locations in the HR diagram indicative of old ages and high masses consistent with the observed lithium depletion previously published. We did not find evidence for the presence of astrometric companions with minimum detectable masses typically >=25 Mjup and face-on, circular orbits with periods between 60-90 d and 3 yr around eight targets. The astrometric and spectroscopic data indicate that about 60-70% of the field L-type dwarfs in our sample with evidence for low-gravity atmospheres are indeed young-to-intermediate-age brown dwarfs of the solar neighborhood with expected ages and masses in the intervals 10-500 Myr and 11-45 Mjup. The peaked-shape of the H-band spectra of L dwarfs, a signpost of youth, appears to be present up to ages of 120-500 Myr and intermediate-to-high gravities.Comment: Accepted for publication in A&

    Litigants in person in private family law cases

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    1. Context (p1-2 of the Report) The Legal Aid, Sentencing and Punishment of Offenders Act (LASPO) 2012 removed most private family cases from the scope of legal aid after April 2013. It was anticipated that the volume and proportion of litigants in person (hereafter LIPs) would increase as a result. The Ministry of Justice commissioned research to explore both the characteristics and support needs of LIPs in private family law cases and their impact on the courts prior to the implementation of legal aid reforms. It was designed to inform policy and practice responses to LIPs following the legal aid changes. 2. Research design (p3-10 and p136-164 of the Report) The study was designed to develop understanding of the range of litigants in person in private family law cases, their behavioural drivers and support needs, and their impact on the court system. The research was designed as a primarily qualitative study focusing on understanding the range of experiences and perspectives, rather than a quantitative study seeking to measure variables. The research included three linked studies: ‱ Intensive Cases Study (ICS). The largest element of the research involved detailed analysis of a sample of 151 cases heard in five courts over a three to four week data collection time frame in each court between January and March 2013. The approach was multi-perspectival, involving observation of the hearing in each case, interviews with the parties and professionals associated with the observed case (subject to consent and availability) and scrutiny of the court file. ‱ Local Contextual Study (LCS). This involved a series of focus groups in each of the five courts with local stakeholders (judges, lawyers, Cafcass and court staff), interviews and observations with local LIP support organisations and observations of public areas such as court counters and waiting rooms. ‱ Secondary Analysis Study (SAS). This involved secondary analysis relating to LIPs of two large national datasets from two current studies led by members of the research team. 3. Main findings 3.1 Characteristics of LIPs (p11-34 of the Report) The major reason for self-representation was an inability to afford a lawyer, with only around one quarter of LIPs indicating that their appearance in person was wholly or partially a matter of choice. Over half of the LIPs observed had had legal representation at some stage during the current proceeding and/or in previous family law proceedings. Only a small minority of LIPs were able to represent themselves competently in all aspects of their family law proceedings. Even those with high levels of education or professional experience struggled with aspects of the legal process. The great majority of LIPs were procedurally (and, where relevant, legally) challenged in some way, with some having no real capacity to advocate for their own or their children’s interests. A wide range of personal vulnerabilities were identified with around half of those observed experiencing one or more vulnerabilities which often added to their difficulties in self-representation and in some cases defeated their attempts to do so. A significant number were also trying to handle quite complex cases. LIPs may create problems for the courts by reason of non-appearances, refusal to engage with proceedings, or, less often, violent and aggressive behaviour. While non-appearances may be quite common, the reasons for apparent resistance to court proceedings, as for violence and aggression, may often be related to litigants’ vulnerabilities. Unmeritorious and serial applications did not appear to be brought any more often by the LIPs in the sample than by represented parties, although having to respond to these applications was another vulnerability faced by some women LIPs. 3.2 Pre-hearing preparations (p35-51 of the Report) Much of the work in a family case is conducted before and between hearings rather than in the courtroom itself. The list of tasks to be accomplished in the pre-court and between-hearing phases is quite extensive and technically and practically demanding. The list includes determining legal merits and translating a dispute into legal form; consideration of mediation; making an application using the correct form and filing and serving correctly; possible negotiation with the other side in the waiting room and subsequent handling of the case (e.g. handling disclosure, preparing and filing statements). The successful completion of these tasks was important for the smooth running of the case and for timely and effective hearings. The extent to which LIPs were able to complete those tasks was highly variable. Understandably, many LIPs struggled with a range of technical tasks, including understanding which application form to use, how to complete it and how to file and serve correctly. Some LIPs faced practical problems such as an inability to access or print out online forms. Many LIPs also did not grasp foundational legal principles or concepts such as the importance of disclosure or the expectation of negotiation or settlement. A significant part of the problem is that the family justice system and the pre-court processes, procedures and tasks are predicated on a full representation model with two trained and experienced lawyers undertaking all these preparatory tasks. At least at the time of the fieldwork, there had been limited adaptation of processes to support LIPs and instead LIPs were largely required to comply with existing processes. There had been comparatively little adaptation of documentation (forms, guidance, letters from court etc) to meet the needs of LIPs. There was limited face-to face contact, advice and support at all stages of the pre-court process and on arrival in the court building before the hearing. The support available from court service staff varied locally but was constrained by concerns about straying into giving legal advice. The reduction in court counter hours and switch to an appointment system in some courts has reduced further the opportunities for face-to-face support. The challenging and complex nature of the pre-hearing tasks, coupled with limited support and advice, was a source of anxiety and stress for many LIPs. It also had consequences for court service staff workloads as they had to deal with correspondence from LIPs or pick up the errors or omissions in LIP paperwork. Some of the problems also had a significant impact on the conduct of the hearing itself. 3.3 In the courtroom (p52-78 of the Report) The court system is based on an adversarial, full representation model with two lawyers presenting their client’s cases to an impartial arbiter – the judge – who will make a decision. The role of the lawyers is central. Hearings where both parties were represented were generally patterned, predictable and efficient. All participants understood their roles without any need for explanation or behaviour management. LIP hearings were far less standardised. There was considerable variation in who picked up the tasks that a lawyer would normally perform in their absence – whether it was a LIP, the judge, the lawyer for the represented party or nobody. There was also variation in how effectively those tasks were done. The data suggested that semi-represented cases had longer final hearings and required more hearings than fully represented and non-represented cases. Cases with a LIP were more likely to require adjudication or be withdrawn or dismissed. Secondary analysis of a dataset of financial remedy contested hearings also suggested that LIP cases were less likely to settle and less likely to settle early than fully represented cases. There was variation in how well LIP hearings appear to work or not work in court. Four types appeared relatively fair and efficient/effective: umbrella semi – the represented party’s lawyer works on behalf of both parties; third party (quasi) lawyer – the children’s lawyer acts as broker for both LIPs; fully inquisitorial judge – the judge takes on the role of lawyer(s) and judge holding-their-own LIPs – a competent LIP manages a simple hearing with support from the judge. Four types of hearing appeared inefficient/ineffective or unfair: “hot potato” hearings - chaotic hearings with disruptive LIPs, adjourned or listed for contested hearings; over-confident LIPs - rambling hearings unable to restrict LIPs to legally relevant matters; out of their depth LIPs – LIPs unable to understand/accomplish tasks resulting in longer or extra hearings and unprotected LIPs - LIPs unable to explore concerns/present case. A combination of factors appears to influence how well courts and LIPs cope. These include matter and hearing type (directions vs. substantive hearing), the approach of the judge and any legal representative, the availability of any facilitative third party and the capacity of the LIP(s). The availability of additional professional (legal) support for the LIP was often key to success. Three of the four types of ‘working’ hearings involved either a supportive lawyer or an activist/inquisitorial judge. Causes of delay included LIPs’ lack of understanding and experience meaning sometimes critical tasks were missed out, were done inadequately or were completed by the LIP only with considerable coaching and support from others, particularly judges. Ensuring equality of arms between parties was a real challenge, notably when a LIP was unaware of their legal entitlements and/or unable to do justice to their case. Judges varied considerably in the extent to which they helped LIPs, in itself a source of potential unfairness. Judicial attempts to support LIPs could be seen as unfair to represented parties in semi-representation cases. Two key ‘legal’ tasks - the preparation of bundles and cross-examination - were beyond the capacity of most LIPs unless they had considerable help. 3.4 The support needs of litigants in person (p79-100 of the Report) The LIP experience was mixed, sometimes better than expected but often stressful and confusing. LIPs reported fear and anxiety about the process, feeling marginalised and bewilderment and confusion, regardless of educational level. Factors that made the experience more positive were judges and sometimes opposing solicitors who took time to explain things and being able to draw upon previous experience of being at court. A degree of self-assurance or confidence was helpful, although over-confidence and an over-estimation of one’s understanding of the process could cause difficulties. The main support needs identified by LIPs were for information about process and procedure, emotional support, practical support and tailored legal advice including broad questions about their entitlements and specific questions about tactics and tasks. LIPs varied enormously in terms both of willingness and ability to seek support and of the effectiveness with which support was sought. A minority of LIPs were proactive in searching for information without any prompting by the courts. The proactive LIPs could be divided into the capable/organised and those with a scattergun/shot in the dark approach, although even the capable/organised could find it difficult to find the information they needed. Reactive LIPs responded to instructions or suggestions from family justice professionals, especially where those instructions were clear and precise. Passive LIPs relied on others to provide help, did not engage with the court process or had chaotic lifestyles. Support for LIPs at the time of the study was disparate, variable and limited. The internet has potential for informing LIPs, as well as some very significant drawbacks in relation to relevance, accuracy as well as accessibility for all. Few of the LIPs interviewed reported using the HMCTS or MoJ websites and those who did reported they did not meet their needs. Further, not all LIPs have access to online resources and, even for those who do, websites cannot adequately substitute for the tailored legal advice that many LIPs require. LIPs reported frustration that organisations like CABx, the court service and Cafcass were not able to offer advice and advised them to seek legal advice that could not be afforded. There is a dearth of free or low-cost legal advice in the community. Family and friends could be very helpful acting as informal supporters, but the development of paid ‘professional’ McKenzie Friends was a source of real concern to judges, lawyers and Cafcass officers. As previous studies have found, the courts did little signposting to sources of support. Professional training in how to support LIPs is needed. The development of support services for LIPs and training for professionals should be informed by, and responsive to, the different needs and help-seeking approaches of LIPs. 4. Policy Implications and Recommendations (p101-125 of the Report) 4.1 LIPS after 1st April 2013: eligibility for legal aid and the ‘new’ LIPs Chapter 6 of the Report considers the policy and practice implications of the findings reported above. The chapter begins with consideration of how far the findings are likely to apply after 1 April 2013. The available evidence suggested that the majority of represented parties in the sample who were in receipt of legal aid would no longer be eligible for legal aid after the LASPO reforms. In comparison with the observed pre-LASPO LIPs, the researchers would expect that LIPs post-LASPO would be less likely to be partially represented and more likely to present with vulnerabilities which affect their capacity to represent themselves effectively and create challenges for the courts in terms of safety at court, testing, disclosure and safeguarding children 4.2 Recommendations The report identified that LIPs have considerable needs for support across several dimensions. It also identified what the researchers consider to be best practices for meeting those needs, based on the team’s review of the literature and the observations and interviews with LIPs and family justice system professionals. It has not been part of the research team’s brief, however, to analyse the cost-benefit of these proposals or to produce a fully worked-up blueprint for change. This section, therefore, summarises the broad recommendations arising from the team’s analysis of the literature and the research data. Further detailed policy and operational consideration will of course be required to determine how these recommendations could be implemented. Information needs ‱ That all relevant family justice communications, including forms, leaflets, practice directions, templates and pro forma, are re-evaluated from the perspective of LIPs and (if necessary) redesigned with their various needs in mind. ‱ That a single authoritative ‘official’ family court website is established with all the resources that a LIP needs in one place. ‱ That the court’s communication with parties prior to the first hearing is used more effectively to convey important information to LIPs. ‱ That judges are encouraged to give LIPs clear verbal instructions and guidance on process and procedure. ‱ That the court service provides increased opportunity for face-to-face inquiries with relevant court staff and that guidelines and training for court staff are devised to facilitate information-giving whilst avoiding giving advice. Emotional/moral support ‱ That there is a presumption that a single family member, friend or volunteer may accompany a LIP in court to offer emotional/moral support without the need to submit a formal CV. ‱ That consideration is given to the development of a code of conduct, practice guidance or regulatory framework for paid/’professional’ McKenzie Friends. Practical support and legal knowledge ‱ That initial legal advice to facilitate dispute resolution and, where necessary, for initial preparation for court proceedings is made universally available. ‱ That providing support for LIPs in a consistent way in both semi-represented and non-represented cases is understood as a key element of the judicial role; and that judicial officers receive appropriate guidance and training to do so. ‱ That measures are introduced to ensure greater availability of and access to exceptional case funding in private family law matters. ‱ That a mechanism is introduced to enable judicial recommendation for the provision of publicly funded representation in the interests of justice. ‱ That the MoJ consider which other forms of legal and procedural assistance outlined in this Chapter for LIPs engaged in court proceedings can feasibly be supported or implemented. Other issues ‱ Follow up independent research is needed to examine the impact of the legal aid reforms on the types and experiences of LIPs, their impact on the court system and the effectiveness of innovations and services to support LIPs

    Spin Resonance and dc Current Generation in a Quantum Wire

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    We show that in a quantum wire the spin-orbit interaction leads to a narrow spin resonance at low temperatures, even in the absence of an external magnetic field. Resonance absorption by linearly polarized radiation gives a dc spin current; resonance absorption by circularly polarized radiation gives a dc electric current or magnetization

    Is Social Media like an Onion?: Exploring the Social Penetration Theory as an Explanation for Viral Responses to Intimate Self-Disclosures

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    A recent public FB post about a personal experience with depression went viral within a week. Within a week this post was reposted on numerous media outlets, and shared by others nearly 500,000 times. This post skipped to the third, affective stage, of the Social Penetration Theory
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