Enabling Realistic Cross-Layer Analysis based on Satellite Physical Layer Traces

We present a solution to evaluate the performance of transport protocols as a function of link layer reliability schemes (i.e. ARQ, FEC and Hybrid ARQ) applied to satellite physical layer traces. As modelling such traces is complex and may require approximations, the use of real traces will minimise the potential for erroneous performance evaluations resulting from imperfect models. Our Trace Manager Tool (TMT) produces the corresponding link layer output, which is then used within the ns-2 network simulator via the additionally developed ns-2 interface module. We first present the analytical models for the link layer with bursty erasure packets and for the link layer reliability mechanisms with bursty erasures. Then, we present details of the TMT tool and our validation methodology, demonstrating that the selected performance metrics (recovery delay and throughput efficiency) exhibit a good match between the theoretical results and those obtained with TMT. Finally, we present results showing the impact of different link layer reliability mechanisms on the performance of TCP Cubic transport layer protocol

Enabling Realistic Cross-Layer Analysis based on Satellite Physical Layer Traces

We present a solution to evaluate the performance of transport protocols as a function of link layer reliability schemes (i.e. ARQ, FEC and Hybrid ARQ) applied to satellite physical layer traces. As modelling such traces is complex and may require approximations, the use of real traces will minimise the potential for erroneous performance evaluations resulting from imperfect models. Our Trace Manager Tool (TMT) produces the corresponding link layer output, which is then used within the ns-2 network simulator via the additionally developed ns-2 interface module. We first present the analytical models for the link layer with bursty erasure packets and for the link layer reliability mechanisms with bursty erasures. Then, we present details of the TMT tool and our validation methodology, demonstrating that the selected performance metrics (recovery delay and throughput efficiency) exhibit a good match between the theoretical results and those obtained with TMT. Finally, we present results showing the impact of different link layer reliability mechanisms on the performance of TCP Cubic transport layer protocol.Comment: 6 pages, 5 figures and 1 table. Submitted at PIMRC 201

Proposal for field sampling of plants and processing in the lab for environmental metabolic fingerprinting

Maier T, Kuhn J, Müller C. Proposal for field sampling of plants and processing in the lab for environmental metabolic fingerprinting. Plant Methods. 2010;6(1): 6.BACKGROUND: Samples for plant metabolic fingerprinting are prepared generally by metabolism quenching, grinding of plant material and extraction of metabolites in solvents. Further concentration and derivatisation steps follow in dependence of the sample nature and the available analytical platform. For plant material sampled in the field, several methods are not applicable, such as, e.g., collection in liquid nitrogen. Therefore, a protocol was established for sample pre-treatment, grinding, extraction and storage, which can be used for analysis of field-collected plant material, which is further processed in the laboratory. Ribwort plantain (Plantago lanceolata L., Plantaginaceae) was used as model plant. The quality criteria for method suitability were high reproducibility, extraction efficiency and handling comfort of each subsequent processing step. RESULTS: Highest reproducibility of results was achieved by sampling fresh plant material in a solvent mixture of methanol:dichloromethane (2:1), crushing the tissue with a hand-held disperser and storing the material until further processing. In the laboratory the material was extracted threefold at different pH. The gained extracts were separated with water (2:1:1 methanol:dichloromethane:water) and the aqueous phases used for analysis by LC-MS, because the polar metabolites were in focus. Chromatograms were compared by calculating a value Xi for similarities. Advantages and disadvantages of different sample pre-treatment methods, use of solvents and solvent mixtures, influence of pH, extraction frequency and duration, and storing temperature are discussed with regard to the quality criteria. CONCLUSIONS: The proposed extraction protocol leads to highly reproducible metabolic fingerprints and allows optimal handling of field-collected plant material and further processing in the laboratory, which is demonstrated for an exemplary field data-set. Calculation of Xi values is a useful tool to judge similarities between chromatograms

Analysis of complex metabolic behavior through pathway decomposition

<p>Abstract</p> <p>Background</p> <p>Understanding complex systems through decomposition into simple interacting components is a pervasive paradigm throughout modern science and engineering. For cellular metabolism, complexity can be reduced by decomposition into pathways with particular biochemical functions, and the concept of elementary flux modes provides a systematic way for organizing metabolic networks into such pathways. While decomposition using elementary flux modes has proven to be a powerful tool for understanding and manipulating cellular metabolism, its utility, however, is severely limited since the number of modes in a network increases exponentially with its size.</p> <p>Results</p> <p>Here, we present a new method for decomposition of metabolic flux distributions into elementary flux modes. Our method can easily operate on large, genome-scale networks since it does not require all relevant modes of the metabolic network to be generated. We illustrate the utility of our method for metabolic engineering of <it>Escherichia coli </it>and for understanding the survival of <it>Mycobacterium tuberculosis </it>(MTB) during infection.</p> <p>Conclusions</p> <p>Our method can achieve computational time improvements exceeding 2000-fold and requires only several seconds to generate elementary mode decompositions on genome-scale networks. These improvements arise from not having to generate all relevant elementary modes prior to initiating the decomposition. The decompositions from our method are useful for understanding complex flux distributions and debugging genome-scale models.</p

Sexual function after suburethral sling removal for dyspareunia

Introduction: Impact on sexual function has received little attention in the medical literature for a long time. Because of the site of insertion of permanent tension free vaginal tape (TVT) the G spot might be affected or the tape might interfere with arousal and sensory stimulation. Recent studies have reported varying degrees of sexual impairment after TVT insertion ranging from 0% to 15% including dyspareunia. Aim: The aim of this study was to evaluate sexual function before and after suburethral sling removal due to postoperative female de novo dyspareunia. As a secondary outcome, general patients' satisfaction with their overall continence situation was assessed. Patients and methods: Between December 2005 and December 2007, we included 18 female patients who complained of de novo dyspareunia after suburethral sling insertion for urinary stress incontinence. All patients filled in an FSFI questionnaire prior to sling removal and at 3 months postoperatively. Additionally, all women were asked to estimate their general satisfaction regarding their continence situation using a Visual Analogue Scale (VAS) from 0 to 10, with 0 being the least satisfying situation and 10 being the most satisfying situation. All patients underwent gynaecological examination including ICS-pelvic organ prolapse staging (ICS-POP score). Results: Of the 18 slings, ten were transobturator tapes (6 × TVT-O, 2 × Monarch, 2 × unknown) and eight were retropubic tapes (7 × TVT, 1 × SPARC). Desire, arousal, lubrication, satisfaction, and pain improved statistically significant. Orgasm scores were low with median scoring of 1.5 scores before and 1.0 scores after sling removal, and they did not change significantly after sling removal. The satisfaction rate deteriorated from a median of 7 (95% confidence interval [CI] 6.3-7.7) to a median of 4 (95% CI 3.7-5.1; p=0.99) but not statistically significant. Conclusions: Sexual function in patients with de novo dyspareuina is likely to improve after sling removal but not in all domains. Bladder function may deteriorat

Supporting bereavement and complicated grief in primary care: a realist review.

BACKGROUND: Bereavement can have significant impacts on physical and mental health, and a minority of people experience complicated and prolonged grief responses. Primary care is ideally situated to offer bereavement care, yet UK provision remains variable and practitioners feel uncertain how best to support bereaved patients. AIM: To identify what works, how, and for whom, in the management of complicated grief (CG) in primary care. DESIGN & SETTING: A review of evidence on the management of CG and bereavement in UK primary care settings. METHOD: A realist approach was taken that aims to provide causal explanations through the generation and articulation of contexts, mechanisms, and outcomes. RESULTS: Forty-two articles were included. Evidence on the primary care management of complicated or prolonged grief was limited. GPs and nurses view bereavement support as part of their role, yet experience uncertainty over the appropriate extent of their involvement. Patients and clinicians often have differing views on the role of primary care in bereavement. Training in bereavement, local systems for reporting deaths, practitioner time, and resources can assist or hinder bereavement care provision. Practitioners find bereavement care can be emotionally challenging. Understanding patients' needs can encourage a proactive response and help identify appropriate support. CONCLUSION: Bereavement care in primary care remains variable and practitioners feel unprepared to provide appropriate bereavement care. Patients at higher risk of complicated or prolonged grief may fail to receive the support they need from primary care. Further research is required to address the potential unmet needs of bereaved patients

Recentering open for those at the margins: three lenses on lurking

Session Description: The group presenting this session was formed through a serendipitous participation in a ‘slow chat’ (#HEdigID) on the topic of OEP. The chat went on long beyond its official end, and we realized that the #HEdigID network was larger than we had observed. It included ‘invisible’ participants who were simply listening, or tuning in once in a while. We began to discuss the practice of ‘lurking’ and the idea of ‘the lurker’. The group conversation which followed revealed some of the complexities of lurking behaviours. What (or who) is a “lurker”? Do we need to rethink what participation means? Why some learners are visible, and others less visible or maybe invisible, remaining on the margins of online and networked learning? Do we need to recenter participation in open spaces – to bring in those who appear to choose to stay on the periphery? It seems there is a need to turn a critical lens onto our assumptions, and think about how ‘privileging the visible’ may constrain and exclude more invisible learners equally interested in learning (Honeychurch et al., 2017; Popovac, M., & Fullwood, C., 2018). Against a prior emphasis on transmission of knowledge, designing for learning in today’s open environments is often ‘designing for participation’. Has the pendulum now swung too far in this direction, such that those who are said to ‘lurk’ are dismissed, derided, or at best, understood through a deficit model? Our proposed lenses on lurking as troublesome, political and ordinary, suggest alternative ways of understanding lurking behaviours, but do not provide an obvious answer to the question of how to engage the lurking learner – or whether the lurker must be engaged. What does learner agency look like in this context? Can we truly design for all? Or should we design for participation – and let lurkers lurk? We are seeking input from participants in online learning spaces – current students or teachers or people who have other roles or with an interest in learning in open environments. Through the discussion/activity, further insights into both the ‘lurker experience’ and inclusive learning design will emerge Session content: Drawing on previous experiences in exploring questions of digital identity and engagement (Author, 2017; Author, 2018), we are proposing a WORKSHOP COMBINED WITH AN OPEN SPACE in order to engage the audience early on so we can gather a different range of answers to our questions. Two interactive walls will be designed, one analogue and another digital. The analogue to be placed in an open space (from day 1) to foster discussion amongst people prior to the workshop, and the digital wall on Padlet to allow remote participation. Pre-workshop feedback from the walls will be combined with further input from participants, followed by the discussion of our proposed lenses, in order to see whether our three lenses are sufficient or whether further lenses emerge from the activity

Understanding Data: Praxis and Politics [webinar]

This research seminar/webinar, hosted by Bath Spa University School of Education, reports on design, experience and outcomes of the Understanding Data: Praxis and Politics project

Three Lenses on Lurking: Making Sense of Digital Silence

In this chapter, the authors provide a critical exploration of the concept of lurking in online learning spaces through a phenomenological inquiry. The authors begin from a position that lurking is often misunderstood – or perhaps not understood – in education, and that the term itself is quite problematic, as it is typically applied to a disparate range of behaviors by those who perceive them as problematic. The authors then propose three heuristic lenses to make sense of lurking behaviors: lurking as troublesome, lurking as ordinary, and lurking as political. These lenses demonstrate that lurking behaviors not only stem from a range of different motivations but are also situated in a variety of contexts, that is, lurking is personal and contextual. The authors’ aim is not to define or redefine lurking for readers but to provide a critical analysis of what digital silence might mean for their students based on their contextual experience and in the light of critical literature. The authors invite readers to be part of the reflexive analysis by considering what lurking might mean in their own teaching contexts

ANÁLISE DA RESISTÊNCIA A CERCOSPORIOSE EM POPULAÇÕES LOCAIS DE MILHO ANALYSIS OF CERCOSPORIOSIS RESISTANCE IN LOCAL MAIZE POPULATIONS

Objetivou-se nesse trabalho investigar o potencial genético de populações locais de milho quanto à resistência a cercosporiose. Foram conduzidos quatro ensaios no oeste de Santa Catarina, sendo avaliados 12 tratamentos (10 variedades locais e 2 testemunhas) em delineamento de blocos completos casualizados, com três repetições. Foram efetuadas seis avaliações da severidade da doença. Os dados foram submetidos a análise de variância conjunta. Diferenças significativas (P&lt;0,01) foram verificadas em todas as fontes de variação. Portanto, conclui-se que existe variabilidade genética para a resistência a cercosporiose nas populações de milho conservadas por agricultores do oeste de Santa Catarina