RISK FACTORS AND CONTEMPORARY MANAGEMENT OF LOW BACK PAIN

Low back pain is common and causes more burden in terms of years lived with disability than any other health condition globally. In most cases, the patho-anatomical cause of low back pain cannot be determined. Less commonly, specific spinal pathologies can be identified as the cause of low back pain, including conditions involving neurologic compromise, such as sciatica and lumbar spinal stenosis. Despite extensive research over the past decades, questions remain in terms of the underlying mechanisms, risk factors, and current treatment options for these conditions. The broad aim of this thesis, therefore, is to contribute to a better understanding of factors associated with low back pain onset and the safety and efficacy of contemporary management strategies. Risk factors associated with the onset of a new episode of low back pain can be divided into those involving long-term exposure (e.g., smoking) and those involving transient or brief exposure to the risk factor (e.g., a fall). A recent case-crossover study identified that commonly endorsed physical and psychosocial triggers (e.g., awkward postures, distracted during an activity) increase substantially the risk of sudden onset low back pain, with odds ratios ranging from 2.7 to 25.0. This study focussed on triggers for an acute episode of low back pain and did not consider the triggers that increased the risk of an episode of longer duration. This is an important issue as most of the costs of low back pain are associated with persistent cases. The study presented in Chapter Two includes the 12-month follow-up of this case-crossover study and examined the association between the previously identified triggers and the risk of a low back pain episode that persisted for greater than six weeks. This study was based on data from 782 patients presenting to primary care clinics for a new episode of low back pain, who were successfully followed-up. Conditional logistic regression models suggested that previously identified psychosocial and physical triggers, such as being fatigued or tired during an activity or manual tasks involving awkward postures, increased the risk of persistent episodes of low back pain, with odds ratios (OR) ranging from 2.9 (95% confidence interval [CI]: 1.3–6.4) to 11.7 (95% CI: 5.4–25.3). The results were similar to those for acute episodes of low back pain, suggesting that controlling exposures to these triggers may prevent not only the cases of low back that resolve within six weeks, but also the cases that persist, which are believed to cause the greatest burden of this condition. While a great proportion of patients with low back pain experience recovery within six weeks, recurrence of low back pain is common. However, estimates of recurrence within one year range from 26% to 84%. Part of this variability can be attributed to different definitions of episodes of low back pain used across studies. Moreover, only a few studies have used appropriate methodology to investigate predictors of recurrence. The study presented in Chapter Three determined the 1-year incidence of recurrence in participants who had recently recovered from an acute episode of low back pain, and identified predictors of future recurrences. This was an inception cohort study with 12 months follow-up. Recurrence was defined based on a 12-month recall of a new episode of pain or a new episode of care seeking with data from 469 participants. The 1-year incidence of recurrence of low back pain was 33%, and the recurrence rate for a new episode of care seeking for low back pain was 18%. Multivariable regression analysis revealed that having more than two previous episodes of low back pain increased the odds of a future recurrence by 3.2 (95% CI: 2.1–4.8). This factor was also associated with recurrent episodes of care seeking (OR: 2.9, 95% CI: 1.7–4.8). No other factors were associated with recurrence. This study contributes to the lack of research on recurrence of low back pain. Patients with low back pain seeking primary health care are often recommended paracetamol as the first line analgesic medication. This medicine is also widely used to treat osteoarthritis. However, a randomised trial published in 2014 concluded that paracetamol was ineffective for acute low back pain, and there was also conflicting evidence for its use in osteoarthritis. The systematic review with meta-analysis of randomised placebo-controlled trials presented in Chapter Four investigated the safety and efficacy of paracetamol in patients with low back pain, as well as neck pain, or osteoarthritis. Searching eight databases revealed 13 trials that met the inclusion criteria. Pain and disability scores were converted to a 0 to 100 scale, and a 9-point threshold was used to define smallest worthwhile effect. Pooling showed no effects of paracetamol on pain (mean difference [MD]: –0.5, 95% CI: –2.9 to 1.9) or disability (MD: 0.4, 95% CI: –0.9 to 1.7) for acute low back pain. No trials investigated the effects of paracetamol for patients with neck pain. Paracetamol had small and not clinically important effects for osteoarthritis in pain relief (MD: –3.7, 95% CI: –5.5 to –1.9) or disability reduction (MD: –2.9, 95% CI: –4.9 to –0.9). Patients taking paracetamol were 3.8 times (95% CI: 1.9– 7.4) more likely to have abnormal test results of liver function compared with placebo. The results of this systematic review support the reconsideration of recommendations to use paracetamol for these conditions. The study was published with an editorial and has received various prizes, including the BMJ 1st prize for the most accesses in 2015. The impact of withdrawing recommendations for paracetamol from clinical guidelines of low back pain is that the use of nonsteroidal anti-inflammatory drugs (NSAIDs), second line analgesic, is set to increase. A comprehensive review and appraisal of the literature on the efficacy and safety of NSAIDs was therefore paramount. Moreover, the effects of NSAIDs for some forms of spinal pain, such as acute low back pain and neck pain, remain uncertain. Chapter Five, therefore, presents a systematic review with meta-analysis of randomised placebo-controlled trials that aimed to determine the efficacy and safety of NSAIDs for low back pain, as well as neck pain, with or without radicular pain. Systematic searches were conducted in five large databases and 35 randomised trials were included in the review. Pain and disability outcomes were converted to a 0 to 100 scale, and a between-group difference of 10 points was used as the smallest worthwhile effect. Numbers needed to treat were also calculated providing the number of participants treated with NSAIDs who would achieve a clinically important pain reduction compared with placebo. Pooling revealed that for every six participants (95% CI: 4 to 10) treated with NSAIDs, only one would benefit from it, considering a between-group difference of 10 points (i.e., compared with placebo) for clinical importance in the short-term. Moreover, only in three of the 14 analyses looking at different types of spinal pain, outcomes, or time points were the pooled treatment effects marginally above our threshold for clinical importance. Additionally, taking NSAIDs increased the risk of developing gastrointestinal adverse events by 2.5 times (95% CI: 1.2–5.2). The initial management of low back pain usually focuses on conservative treatments, including analgesic medications. When conservative treatments are unsuccessful, surgery may be considered. Sciatica is a common indication for spine surgery, but at present the clinical course of this condition following surgery remains largely unknown. Therefore, the systematic review with meta-analysis of cohort studies presented in Chapter Six investigated the clinical course of pain and disability in patients who had surgery for sciatica. The searches were conducted in three large databases and 40 publications (39 cohort studies) were included. Pain and disability scores were converted to a common 0 to 100 scale and modelled as a function of time. Generalised estimating equations revealed that the pooled mean leg pain intensity before surgery was 75.2 (95% CI: 68.1 to 82.4) and the mean disability was 55.1 (95% CI: 52.3 to 58.0). Pooled mean leg pain (15.3, 95% CI: 8.5 to 22.1) and disability (15.5, 95% CI: 13.3 to 17.6) reduced substantially after three months. At five years, patients still reported moderate levels of leg pain (21.0, 95% CI: 12.5 to 29.5) and disability (13.1, 95% CI: 10.6 to 15.5). These findings suggest that patients with sciatica experience rapid improvements in the first three months after surgery, but are not likely to experience full recovery (i.e., absence of pain or disability) in the long-term. Lumbar spinal stenosis is the fastest-growing indication for spine surgery among older people. However, surgeons usually rely on their own preferences to decide on the best surgical technique for their patient. The systematic review and meta-analysis presented in Chapter Seven investigated the efficacy of surgery for lumbar spinal stenosis, and the effectiveness of various surgical options for this condition. The searches conducted on seven databases revealed limited evidence, as no surgical placebo-controlled trials were found. The 24 randomised trials included in the review compared various surgical options for lumbar spinal stenosis. Pain and disability scores were converted to a 0 to 100 scale. Pooling suggested that fusion offered no additional benefits over decompression surgery alone on pain (MD: –0.3, 95% CI: –7.3 to 6.7) or disability (MD: 3.3, 95% CI: –6.1 to 12.6). The interspinous process spacers alone were not more effective than conventional decompression in pain relief (MD: –0.6, 95% CI: –8.1 to 7.0) or disability reduction (MD: 1.3, 95% CI: –4.5 to 7.0), but showed small effects when compared with decompression plus fusion on disability (MD: 5.7, 95% CI: 1.3 to 10.0). This review was originally published in PLoS ONE in 2015, but has since then been updated and published in the Cochrane Database of Systematic Reviews, presented in this thesis as an appendix. The updated results provide current evidence on the surgical options for lumbar spinal stenosis, and could be used to guide clinical decision-making in this contentious area. Even though the effects of surgical procedures for patients with lumbar spinal stenosis remain unclear, the rates of fusion procedures have increased in the United States in recent times. It is unknown, however, whether these trends are happening elsewhere. Moreover, further information on complications could better inform surgeons, referring physicians, and patients about risks of surgical procedures. The population-based health record linkage study presented in Chapter Eight determined the trends in hospital admission and surgery for lumbar spinal stenosis in Australia, and investigated associated complications and health care use. The Centre for Health Record Linkage was used to link data of admissions, discharges, and transfers records from all public and private hospitals in New South Wales between 2003 and 2013. In one decade, the age-standardised rate of hospital admissions for lumbar spinal stenosis increased from 34.8 to 39.3 per 100,000 people. In 2013, the total costs for lumbar spinal stenosis were AU $46.1 million. Decompression rates increased from 19.0 to 22.1 per 100,000 people during 2003–2013, while the rates of simple fusion doubled, from 1.3 to 2.8 per 100,000 people. The most significant increase, however, occurred for complex fusion, from 0.6 to 2.4 per 100,000 people – a 4-fold increase in the same 10-year period. Mean hospital costs with decompression surgery were AU$12,168, while simple and complex fusion cost AU $30,811 and AU$32,350, respectively. Complex fusion procedures increased the odds of major complications by 4.1 (95% CI: 1.7–10.1) compared with decompression alone. This study confirms that in Australia the number of complex fusion procedures is increasing at a much faster rate than any other surgical procedure for lumbar spinal stenosis, though it is associated with increased risk of major complications and resource use. Overall, the studies presented in this thesis provide a substantial contribution to the understanding of the mechanisms and risk factors of low back pain. The identification of transient risk factors for persistent low back pain could help develop better preventive strategies. Although a great proportion of patients experience recovery within six weeks, it is now clear that a third is expected to have a recurrence, with multiple previous episodes being the only significant predictor of future recurrences. This thesis also contributes to a better understanding of current management strategies for low back pain. Paracetamol is ineffective for acute low back pain, but NSAIDs provide small effects in pain relief and disability reduction. Recommendations in clinical practice guidelines on pharmacological interventions should be reviewed. Although patients refractory to conservative treatments are frequently referred to surgery, the postoperative clinical course of sciatica is not as favourable as previously thought. Furthermore, despite the lack of evidence on surgical options for lumbar spinal stenosis, fusion surgery is increasing at an alarming rate in Australia

The internet of everything sustainable advantages and synergies in clustered retail

The Internet of Everything (IoE) is a concept introduced by Cisco as the succeeding phase of the Internet of Things (IoT), consisting in creating a network connection of objects, people, processes and data (Cisco 2013). The novelty in this concept is that instead of referring simply to the network connection of physical objects, the IoE allows for connected ‘things’ to send higher-level information back to machines, computers, and people for further evaluation and decision making (Cisco 2013). ! This dissertation aims to analyze the IoE concept’s strategic impact in clustered retails. In order to contextualize the concept and, later, perform the correct analysis of the subject, a review of the technologies at its core and Cisco’s perspective of IoE’s realization in retail is made. Furthermore, making up the core of sustainable strategic advantage analysis, a review is made regarding Resource-based View (RBV) model according to Barney’s framework and Customer Relationship Management (CRM) through Payne and Frow’s framework. In the subsequent chapter, the model of analysis is explained, incorporating the proposition that a smartphone application is, at a first phase, the optimal presentation layer for consumers. Empirical data collection is then performed through a questionnaire intended to give answer to the dissertation’s research question of sustainable competitive advantage. The results, collected from a population sample of 120 respondents, ascertained the importance of the smartphone app and its most appealing features. The strategic applicability of IoE in clustered retail is, then, confirmed through the application of both RBV and CRM models, which verify the system’s potential to generate sustained competitive advantage, confirming the dissertation’s main objective.A Internet of Everything (IoE) – ou a Internet de Tudo - é um conceito introduzido pela Cisco como fase sucessora da Internet of Things (IoT) – ou a Internet das Coisas -, caracterizada por criar uma rede de conectiva de objectos, pessoas, processos e informação (Cisco 2013). A novidade introduzida por este conceito é de que, em vez de fazer referência apenas à rede de conexões de objectos físicos, o IoE permite à rede de ‘coisas’ o envio de informação de qualidade superior de volta para máquinas, computadores, e pessoas para avaliações e decisões adicionais (Cisco 2013). O objectivo desta dissertação assenta na análise do impacto estratégico do conceito de IoE em retalho conglomerado. De modo a contextualizar o conceito e, mais tarde, proceder à correcta análise do tópico, uma revisão da tecnologia basilar e da perspectiva da Cisco em relação à implementação da IoE em retalho é realizada. Ademais, constituindo a origem da análise à vantagem estratégica sustentável, uma revisão é feita a ambos os modelo de Resource-base View (RBV), de acordo com enquadramento de Barney, e Customer Relationship Management (CRM) – ou Gestão de Relacionamento com o Cliente -, através do enquadramento de Payne e Frow. No capítulo subsequente, o modelo de análise é explicado, incluindo a proposição que uma aplicação para smartphone seria, numa primeira fase, o canal de ligação e apresentação ao consumidor ideal. A recolha de dados empíricos é, de seguida, executada através de um questionário, pretendendo dar resposta dar resposta à pergunta central da dissertação relativa à vantagem competitiva sustentável. Os resultados, recolhidos de uma amostra populacional de 120 inquiridos, determinaram a importância da aplicação para smartphones e quais as suas características mais apelativas. A aplicabilidade estratégica da IoE em retalho conglomerado é, assim, confirmada através da aplicação de ambos os modelos de RBV e CRM, que certificam o potencial do sistema em gerar vantagem competitiva sustentável, confirmando assim o objectivo principal da dissertação

Teachers' and student teachers' reflections on teaching english a globalized world

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão, Programa de Pós-Graduação em Inglês: Estudos Linguísticos e Literários, Florianópolis, 2015.Abstract : The globalization process has favored the intensification of the cross-border interactions around the world, and promoted English as a language of global communication. Due to that, many studies have discussed this new status of English as well as its implications for English language teaching. In this context, this study deals with the perceptions of four professors and six student teachers regarding the teaching of English and its new status in the world today. The research covered three main topics: native speaker models and the adoption of a standard variety, culture in language teaching, and challenges in the Brazilian context. The qualitative method of inquiry was adopted in the research and mp3 recorded structured interviews were the instruments of data collection. The research concluded that, although the participants opposed the native speaker model as a goal of pronunciation, they demonstrated a conservative stance toward the adoption of a native standard variety in English teaching. In regard to the teaching of culture, some participants? perceptions reflected traditional approaches, whereas some other participants? perceptions reflected the implications of the new status of English for language teaching. Finally, concerning the challenges of teaching English in Brazil, the majority of participants pointed the public school as the main obstacle to the democratization of English in Brazil.O processo de globalização favoreceu a intensificação das relações transnacionais ao redor do mundo, e promoveu o inglês como língua de comunicação global. Por isso, muitos estudos discutiram esse novo status do inglês, assim como as suas implicações para o ensino de língua inglesa. Nesse contexto, o presente estudo trata das reflexões de quatro professores e seis professores em formação a respeito de suas percepções sobre ensinar inglês de acordo com seu novo status no mundo de hoje. A pesquisa cobriu três tópicos principais: modelos de falante nativo e a adoção de uma variedade padrão, cultura no ensino de línguas, e os desafios do contexto brasileiro. Foi adotado o método qualitativo de investigação e entrevistas estruturadas gravadas em mp3 foram os instrumentos de coleta de dados. A pesquisa concluiu que, embora os participantes se opuseram ao modelo de falante nativo como um objetivo de pronúncia, eles adotaram uma posição conservadora em relação à adoção de uma variedade padrão no ensino de inglês. No que tange ao ensino de cultura, algumas percepções dos participantes refletiram abordagens tradicionais, ao passo que outras estavam ligadas às implicações do novo status do inglês para o ensino de línguas. No que diz respeito aos desafios de ensinar inglês no Brasil, a maioria dos participantes apontou a escola pública como o principal obstáculo à democratização do inglês no Brasil

Resolução distribuída de interacções de serviços na Internet

A proliferação da Internet levou ao crescimento substancial do número de serviços disponibilizados em aplicações como Email, VoIP e WWW, que conduziu à inevitável ocorrência de interacções, com comportamentos indesejáveis. A resolução das interacções de serviços na Internet deve obedecer às características deste meio e como tal deve ter uma arquitectura distribuída. O projecto desenvolvido nesta dissertação apresenta uma solução baseada numa arquitectura distribuída, onde cada nó recorre à resolução prestada por um conselheiro[1]. Finalmente é apresentada uma proposta para a implementação do conselheiro com utilização de fórmulas deônticas e assente em tecnologia Java. O funcionamento da solução foi testado e adaptado com a aplicação de correio electrónico JAMES (Java Apache Mail Enterprise Server) da Apache Software Foundation (ASF). Os resultados obtidos demonstraram o funcionamento da solução de acordo com os objectivos do projecto e o desempenho do sistema não comprometeu o nível de serviço da aplicação de Email.info:eu-repo/semantics/publishedVersio

Quem trabalhou remotamente no Brasil? Desigualdades evidenciadas pela pandemia

There is some consensus that the pandemic can widen pre-existing inequalities in the labor market and that an essential issue concerns the unequal possibilities of working remotely. This study analyzes inequalities in remote work in Brazil through descriptive analyzes and Probit regressions using PNAD COVID-19 microdata. We have found that workers with the least possibilities for remote work were the poorest, males, rural residents, non-whites, youngest, without college education, self-employed or wage workers from the private sector and agriculture workers. An important part of that stems from differences in selection into occupations; however, some variables maintained important independent effects, especially the college education and the labor income. The pandemic, regarding the possibility of remote work, had the effect of widening the existing inequalities, favoring the wealthier, more educated, and more formalized workers and imposing on the others the need to choose between employment and income versus risk of contagion.Existe certo consenso de que a pandemia pode ampliar desigualdades preexistentes no mercado de trabalho e que uma questão essencial são as possibilidades desiguais de trabalhar remotamente. Este estudo avalia as desigualdades no trabalho remoto no Brasil por meio de análises descritivas e modelos Probit aplicados aos microdados da PNAD COVID-19. Constatamos que os trabalhadores que menos trabalharam remotamente foram os mais pobres, homens, residentes rurais, não brancos, mais jovens, sem ensino superior, autônomos ou assalariados sem carteira de trabalho assinada e trabalhadores agrícolas. Uma parte importante disso decorre de diferenças na seleção nas ocupações; mas, algumas variáveis mantiveram efeitos independentes importantes, principalmente a educação superior e a renda do trabalho. Logo, quanto à possibilidade de trabalho remoto, a pandemia teve efeito de ampliar desigualdades existentes, favorecendo os trabalhadores mais ricos, escolarizados e formalizados e impondo aos demais a necessidade de escolha entre emprego e renda e risco de contágio

Differences in the distribution and abundance of Teredinidae (Mollusca: Bivalvia) along the coast of Rio de Janeiro state, Brazil

Teredinidae são moluscos marinhos ou estuarinos perfuradores e degradadores de madeira. Avaliar sua distribuição e abundância se mostrou importante, uma vez que a destruição de madeira é ainda subestimada, sobretudo em regiões tropicais. Dados de literatura têm mostrado também que temperatura e salinidade são dois fatores que afetam fisiologicamente as espécies de Teredinidae. Os objetivos deste trabalho foram avaliar a distribuição e abundância de Teredinidae ao longo da costa do Rio de Janeiro, em relação ao padrão de temperatura e sua variação. Coletores artificiais de pinho foram imersos por três meses em 14 localidades em quatro regiões do estado. Sete espécies foram registradas e identificadas pela forma de suas palhetas. Os maiores valores de densidade e riqueza específica foram registrados na Baía da Ilha Grande e os menores, na Baía de Guanabara. Foi observado um gradiente na abundância relacionado à temperatura. As espécies mais abundantes foram Lyrodus floridanus e Teredo furcifera. Além da temperatura, a diferença na disponibilidade de madeira entre as regiões parece ser também um fator importante. Pela primeira vez registramos a ocorrência de Bankia destructa para o Rio de Janeiro, embora este registro não signifique introdução ou expansão de distribuição.Teredinidae are wood-boring mollusks found in marine and estuarine regions. Evaluation of the distribution and abundance of Teredinidae is a very important task, as the impact of the destruction of wood in man-made structures is still underestimated, mainly in tropical regions. It is also know that temperature and salinity are key factors affecting the abundance and activity of Teredinidae due to their effects on the physiological responses of Teredinidae. The aim of this study was to evaluate the distribution and abundance of Teredinidae along the Rio de Janeiro coast according to temperature range and pattern. Artificial pine collectors were used and remained immersed for three months in four regions at 14 sites. We recorded seven species of Teredinidae, identified according to their pallets. Ilha Grande Bay was the region with the highest density and species richness, and the region with the lowest was Guanabara Bay. One gradient of abundance related to temperature was found. The most abundant species were Lyrodus floridanus and Teredo furcifera. Besides temperature, wood availability among regions was another important factor. For the first time, we recorded the occurrence of Bankia destructa on the Rio de Janeiro coast, but this record does not indicate any species introduction or expanding distribution range

Dendrogram distance: an evaluation metric for generative networks using hierarchical clustering

We present a novel metric for generative modeling evaluation, focusing primarily on generative networks. The method uses dendrograms to represent real and fake data, allowing for the divergence between training and generated samples to be computed. This metric focus on mode collapse, targeting generators that are not able to capture all modes in the training set. To evaluate the proposed method it is introduced a validation scheme based on sampling from real datasets, therefore the metric is evaluated in a controlled environment and proves to be competitive with other state-of-the-art approaches