Leanness na manutenção aeronáutica: o caso FAP

Os sistemas de armas da Força Aérea Portuguesa (FAP) têm por missão a defesa militar de Portugal, através de operações aéreas e da defesa do espaço aéreo nacional, sendo o F-16 o principal avião de ataque em uso nesta organização. Neste sentido, e tendo em conta o actual contexto económico mundial, as organizações devem rentabilizar todos os recursos disponíveis, custos associados e optimizar processos de trabalho. Tendo por base os pressupostos anteriores, o presente estudo pretende analisar a implementação de lean na FAP, uma vez que esta filosofia assenta na eliminação de desperdícios com vista a uma melhoria da qualidade e diminuição de tempos e custos. Posto isto, a análise deste trabalho vai recair sobre a área de manutenção do F-16, em concreto na Inspeção de Fase (IF), um tipo de manutenção que esta aeronave realiza a cada trezentas horas de voo. O estudo de caso vai incidir em dois momentos da IF: o primeiro ponto relaciona-se com o processamento da recolha de dados para a reunião preliminar onde são definidas, para as áreas de trabalho executantes, as ações de manutenção a realizar com a paragem da aeronave. Deste modo, pretende-se averiguar as causas inerentes aos atrasos verificados para a realização desta reunião. O segundo ponto em observação compreende a informação obtida através da aplicação informática SIAGFA, em uso na FAP, para o processamento de dados de manutenção das quatro aeronaves que inauguraram a IF com a filosofia lean. Esta análise permitiu perceber o número de horas de trabalho dispendidas (em média pelas quatro aeronaves) por cada uma das cartas de trabalho, verificando-se que as cartas adicionais comportam mais horas; foi possível compreender quais as áreas de trabalho consideradas críticas; foram identificados os dias de trabalho realizado e tempos de paragem sem qualquer tipo de intervenção. Foi ainda avaliado, por aeronave, o número de horas de trabalho realizadas na IF e quais os constrangimentos que se verificaram nas aeronaves, que não realizaram a IF no tempo definido para tal.

Leanness e manutenção produtiva total (TPM): modelo de produtividade e competitividade: estudo de caso

O presente trabalho tem como objectivo apresentar a filosofia lean, qual a sua origem e evolução, bem como, os princípios em que se baseia. Na revisão bibliográfica efectuada, são identificadas e caracterizadas as mais importantes ferramentas desta filosofia, nomeadamente o kaizen, VSM, 5“S”, TPM, controlo visual e takt time numa linha móvel, evidenciando para cada uma, qual a sua mais valia no processo de melhoria. A metodologia utilizada neste trabalho é o estudo de caso, visto ser a mais adequada para a questão relevante de investigação identificada. A empresa onde é efectuado o estudo de caso opera no mercado de manutenção aeronáutica, sendo a investigação centrada no processo de reparação de motores aeronáuticos. Com maior detalhe apresentam-se as actividades de manutenção após conclusão da avaliação do motor, sendo de destacar a implementação de fluxo, controlo visual, trabalho padrão e de uma linha de montagem a velocidade constante para efectuar as tarefas de montagem final. A utilização desta última ferramenta lean, a maioria das vezes associada a processos de fabricação, é inovadora, visto nenhuma outra empresa deste segmento de mercado usar esta abordagem num processo de manutenção de motores aeronáuticos. Os resultados obtidos no estudo de caso confirmam a melhoria da eficiência global da empresa, bem como, a adequação desta filosofia de gestão à manutenção de motores aeronáuticos. Conseguiu-se evidenciar que a empresa, ao aplicar a metodologia lean, entrega aos seus clientes produtos com qualidade e na data acordada, mantendo a sua competitividade no mercado e incrementando a produtividade. O envolvimento, criatividade e comprometimento de todos os colaboradores da empresa na implementação destas ferramentas lean são factores críticos no sucesso deste processo de melhoria contínua.

Lean construction: Arenas of enactment, models of diffusion and the meaning of 'leanness'

The existing literature on lean construction is overwhelmingly prescriptive with little recognition of the social and politicised nature of the diffusion process. The prevailing production-engineering perspective too often assumes that organizations are unitary entities where all parties strive for the common goal of 'improved performance'. An alternative perspective is developed that considers the diffusion of lean construction across contested pluralistic arenas. Different actors mobilize different storylines to suit their own localized political agendas. Multiple storylines of lean construction continuously compete for attention with other management fashions. The conceptualization and enactment of lean construction therefore differs across contexts, often taking on different manifestations from those envisaged. However, such localized enactments of lean construction are patterned and conditioned by pre-existing social and economic structures over which individual managers have limited influence. Taking a broader view, 'leanness' can be conceptualized in terms of a quest for structural flexibility involving restructuring, downsizing and outsourcing. From this perspective, the UK construction industry can be seen to have embarked upon leaner ways of working in the mid-1970s, long before the terminology of lean thinking came into vogue. Semi-structured interviews with construction sector policy-makers provide empirical support for the view that lean construction is a multifaceted concept that defies universal definition.

Effects of Bovine Somatotropin and Revalor-S® on Growth Performance and Carcass Leanness in Beef Cattle

Twenty crossbred steers were used to evaluate bovine somatotropin (bST) and an anabolic steroid implant, Revalor-S® (REV), to improve growth and increase carcass leanness. During the first 70 days on feed, bST-treated steers tended to improve live weight gains, consume more feed, and numerically improve feed utilization for growth. The implanted steers grew faster and utilized feed better than steers not implanted with REV. The improvement in gain and feed utilization for growth was maintained throughout the feeding period for REV-implanted steers. At slaughter, REV steers had heavier carcasses which resulted in more pounds of muscle, bone, and fat. When adjusted for hot carcass weight, bST increased leanness of the carcass as evident by the increased weight of the semitendinosus muscle, more pounds of dissected lean, and fewer pounds of dissected fat. Thus, REV and bST can be used to improve growth performance and increase carcass leanness.

What is a healthy weight for middle aged women?

OBJECTIVE: To explore associations between body mass index (BMI) and selected indicators of health and well-being and to suggest a healthy weight range (based on BMI) for middle aged Australian women. DESIGN: population based longitudinal study (cross-sectional baseline data). SUBJECTS: 13431 women aged 45-49 y who participated in the baseline survey for the Australian Longitudinal Study on Women's Health. RESULTS: Forty-eight percent of women had a BMI>25kg/m(2). Prevalence of medical problems (for example, hypertension, diabetes), surgical procedures (cholescystectomy, hysterectomy) and symptoms (for example, back pain) increased monotonically with BMI, while indicators of health care use (for example, visits to doctors) showed a 'J' shaped relationship with BMI. Scores for several sub-scales of the MOS short form health survey (SF36) (for example, general health, role limitations due to emotional difficulties, social function, mental health and vitality) were optimal when BMI was around 19-24 kg/m(2). After adjustment for area of residence, education, smoking, exercise and menopausal status, low BMI was associated with fewer physical health problems than mid-level or higher BMI, and the nationally recommended BMI range of 20-25 was associated with optimum mental health, lower prevalence of tiredness and lowest use of health services. CONCLUSIONS: Acknowledging the limitations of the cross-sectional nature of these data, the results firmly support the benefits of leanness in terms of reducing the risk of cardiovascular disease, diabetes and gall bladder disease. The findings are moderated, however, by the observation that both low and high BMI are associated with decreased vitality and poorer mental health. The optimal range for BMI appears to be about 19-24 kg/m(2). From a public health perspective this study provides strong support for the recommended BMI range of 20-25 as an appropriate target for the promotion of healthy weight in middle aged Australian women.

Smoking and relative body weight: An international perspective from the WHO MONICA project

Study objective-To investigate the magnitude and consistency of the associations between smoking and body mass index (BMI) in different populations. Design-A cross sectional study. Setting and participants-About 69000 men and women aged 35-64 years from 42 populations participating in the first WHO MONICA survey in the early and mid 1980s. Main restults-Compared to never smokers, regular smokers had significantly (p < 0.05) lower median BMI in 20 (men) and 30 (women) out of 42 populations (range -2.9 to 0.5kg/m(2)). There was no population in which smokers had a significantly higher BMI than never smokers. Among men, the association between leanness and smoking was less apparent in populations with relatively low proportions of regular smokers and high proportions of ex-smokers. Ex-smokers had significantly higher BMI than never smokers in 10 of the male populations but in women no consistent pattern was observed. Adjustment for socioeconomic status did not affect these results. Conclusions-Although in most populations the association between smoking and BMI is similar, the magnitude of this association may be affected by the proportions of smokers and ex-smokers in these populations.

Body mass index and risk of head and neck cancer in a pooled analysis of case-control studies in the International Head and Neck Cancer Epidemiology (INHANCE) Consortium

Methods We pooled data from 17 case-control studies including 12 716 cases and the 17 438 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for associations between body mass index (BMI) at different ages and HNC risk, adjusted for age, sex, centre, race, education, tobacco smoking and alcohol consumption. Results Adjusted ORs (95% CIs) were elevated for people with BMI at reference (date of diagnosis for cases and date of selection for controls) < 18.5 kg/m(2) (2.13, 1.75-2.58) and reduced for BMI > 25.0-30.0 kg/m(2) (0.52, 0.44-0.60) and BMI >= 30 kg/m(2) (0.43, 0.33-0.57), compared with BMI > 18.5-25.0 kg/m(2). These associations did not differ by age, sex, tumour site or control source. Although the increased risk among people with BMI < 18.5 kg/m(2) was not modified by tobacco smoking or alcohol drinking, the inverse association for people with BMI > 25 kg/m(2) was present only in smokers and drinkers. Conclusions In our large pooled analysis, leanness was associated with increased HNC risk regardless of smoking and drinking status, although reverse causality cannot be excluded. The reduced risk among overweight or obese people may indicate body size is a modifier of the risk associated with smoking and drinking. Further clarification may be provided by analyses of prospective cohort and mechanistic studies.

Body mass index and risk of head and neck cancer in a pooled analysis of case-control studies in the International Head and Neck Cancer Epidemiology (INHANCE) Consortium.

BACKGROUND: Head and neck cancer (HNC) risk is elevated among lean people and reduced among overweight or obese people in some studies; however, it is unknown whether these associations differ for certain subgroups or are influenced by residual confounding from the effects of alcohol and tobacco use or by other sources of biases. METHODS: We pooled data from 17 case-control studies including 12 716 cases and the 17 438 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for associations between body mass index (BMI) at different ages and HNC risk, adjusted for age, sex, centre, race, education, tobacco smoking and alcohol consumption. RESULTS: Adjusted ORs (95% CIs) were elevated for people with BMI at reference (date of diagnosis for cases and date of selection for controls) 25.0-30.0 kg/m(2) (0.52, 0.44-0.60) and BMI >/=30 kg/m(2) (0.43, 0.33-0.57), compared with BMI >18.5-25.0 kg/m(2). These associations did not differ by age, sex, tumour site or control source. Although the increased risk among people with BMI 25 kg/m(2) was present only in smokers and drinkers. CONCLUSIONS: In our large pooled analysis, leanness was associated with increased HNC risk regardless of smoking and drinking status, although reverse causality cannot be excluded. The reduced risk among overweight or obese people may indicate body size is a modifier of the risk associated with smoking and drinking. Further clarification may be provided by analyses of prospective cohort and mechanistic studies.

Retinoblastoma Protein Knockdown Favors Oxidative Metabolism and Glucose and Fatty Acid Disposal in Muscle Cells.

Deficiency in the retinoblastoma protein (Rb) favors leanness and a healthy metabolic profile in mice largely attributed to activation of oxidative metabolism in white and brown adipose tissues. Less is known about Rb modulation of skeletal muscle metabolism. This was studied here by transiently knocking down Rb expression in differentiated C2C12 myotubes using small interfering RNAs. Compared with control cells transfected with non-targeting RNAs, myotubes silenced for Rb (by 80-90%) had increased expression of genes related to fatty acid uptake and oxidation such as Cd36 and Cpt1b (by 61% and 42%, respectively), increased Mitofusin 2 protein content (∼2.5-fold increase), increased mitochondrial to nuclear DNA ratio (by 48%), increased oxygen consumption (by 65%) and decreased intracellular lipid accumulation. Rb silenced myotubes also displayed up-regulated levels of glucose transporter type 4 expression (∼5-fold increase), increased basal glucose uptake, and enhanced insulin-induced Akt phosphorylation. Interestingly, exercise in mice led to increased Rb phosphorylation (inactivation) in skeletal muscle as evidenced by immunohistochemistry analysis. In conclusion, the silencing of Rb enhances mitochondrial oxidative metabolism and fatty acid and glucose disposal in skeletal myotubes, and changes in Rb status may contribute to muscle physiological adaptation to exercise. J. Cell. Physiol. 231: 708-718, 2016. © 2015 Wiley Periodicals, Inc.

DEPTOR Cell-Autonomously Promotes Adipogenesis, and Its Expression Is Associated with Obesity

DEP domain-containing mTOR-interacting protein (DEPTOR) inhibits the mechanistic target of rapamycin (mTOR), but its in vivo functions are unknown. Previous work indicates that Deptor is part of the Fob3a quantitative trait locus (QTL) linked to obesity/leanness in mice, with Deptor expression being elevated in white adipose tissue (WAT) of obese animals. This relation is unexpected, considering the positive role of mTOR in adipogenesis. Here, we dissected the Fob3a QTL and show that Deptor is the highest-priority candidate promoting WAT expansion in this model. Consistently, transgenic mice overexpressing DEPTOR accumulate more WAT. Furthermore, in humans, DEPTOR expression in WAT correlates with the degree of obesity. We show that DEPTOR is induced by glucocorticoids during adipogenesis and that its overexpression promotes, while its suppression blocks, adipogenesis. DEPTOR activates the proadipogenic Akt/PKB-PPAR-gamma axis by dampening mTORC1-mediated feedback inhibition of insulin signaling. These results establish DEPTOR as a new regulator of adipogenesis.

Ractopamine as a Metabolic Modifier Feed Additive for Finishing Pigs: A Review

The beta-adrenergic agonist ractopamine is increasingly used in the swine industry due to higher consumer demand for leaner pork products. Redirecting nutrients to favor leanness rather than fat deposition, ractopamine improves growth and carcass traits of finishing pigs. However, the impact of this agonist on pork quality is not clearly defined. Understanding the biological effects of dietary ractopamine dose, treatment period, lysine levels, and the lysine to metabolizable energy ratio will help pork producers achieve improvements in animal performance, carcass leanness, and economic efficiency in swine production systems.

Ractopamine as a metabolic modifier feed additive for finishing pigs: a review

The β-adrenergic agonist ractopamine is increasingly used in the swine industry due to higher consumer demand for leaner pork products. Redirecting nutrients to favor leanness rather than fat deposition, ractopamine improves growth and carcass traits of finishing pigs. However, the impact of this agonist on pork quality is not clearly defined. Understanding the biological effects of dietary ractopamine dose, treatment period, lysine levels, and the lysine to metabolizable energy ratio will help pork producers achieve improvements in animal performance, carcass leanness, and economic efficiency in swine production systems.

THE RELATIONSHIP BETWEEN OBESITY AND PSYCHOLOGICAL GENERAL WELL-BEING IN UNITED STATES WOMEN

While clinical studies have shown a negative relationship between obesity and mental health in women, population studies have not shown a consistent association. However, many of these studies can be criticized regarding fatness level criteria, lack of control variables, and validity of the psychological variables.^ The purpose of this research was to elucidate the relationship between fatness level and mental health in United States women using data from the First National Health and Nutrition Examination Survey (NHANES I), which was conducted on a national probability sample from 1971 to 1974. Mental health was measured by the General Well-Being Schedule (GWB), and fatness level was determined by the sum of the triceps and subscapular skinfolds. Women were categorized as lean (15th percentile or less), normal (16th to 84th percentiles), or obese (85th percentile or greater).^ A conceptual framework was developed which identified the variables of age, race, marital status, socioeconomic status (education), employment status, number of births, physical health, weight history, and perception of body image as important to the fatness level-GWB relationship. Multiple regression analyses were performed separately for whites and blacks with GWB as the response variable, and fatness level, age, education, employment status, number of births, marital status, and health perception as predictor variables. In addition, 2- and 3-way interaction terms for leanness, obesity and age were included as predictor variables. Variables related to weight history and perception of body image were not collected in NHANES I, and thus were not included in this study.^ The results indicated that obesity was a statistically significant predictor of lower GWB in white women even when the other predictor variables were controlled. The full regression model identified the young, more educated, obese female as a subgroup with lower GWB, especially in blacks. These findings were not consistent with the previous non-clinical studies which found that obesity was associated with better mental health. The social stigma of being obese and the preoccupation of women with being lean may have contributed to the lower GWB in these women. ^

The psychology of eating,

Bibliography: p. 292-305.