Bayesian Ideas in Survey Sampling: The Legacy of Basu

Survey sampling and, more generally, Official Statistics are experiencing an important renovation time. On one hand, there is the need to exploit the huge information potentiality that the digital revolution made available in terms of data. On the other hand, this process occurred simultaneously with a progressive deterioration of the quality of classical sample surveys, due to a decreasing willingness to participate and an increasing rate of missing responses. The switch from survey-based inference to a hybrid system involv- ing register-based information has made more stringent the debate and the possible resolution of the design-based versus model-based approaches con- troversy. In this new framework, the use of statistical models seems unavoid- able and it is today a relevant part of the official statistician toolkit. Models are important in several different contexts, from Small area estimation to non sampling error adjustment, but they are also crucial for correcting bias due to over and undercoverage of administrative data, in order to prevent potential selection bias, and to deal with different definitions and/or errors in the measurement process of the administrative sources. The progressive shift from a design-based to a model-based approach in terms of super-population is a matter of fact in the practice of the National Statistical Institutes. How- ever, the introduction of Bayesian ideas in official statistics still encounters difficulties and resistance. In this work, we attempt a non-systematic review of the Bayesian development in this area and try to highlight the extra ben- efit that a Bayesian approach might provide. Our general conclusion is that, while the general picture is today clear and most of the basic topics of survey sampling can be easily rephrased and tackled from a Bayesian perspective, much work is still necessary for the availability of a ready-to-use platform of Bayesian survey sampling in the presence of complex sampling design, non-ignorable missing data patterns, and large datasets

Metodologia - O Sector Informal em Moçambique: Resultados do Primeiro Inquérito Nacional (2005)

The Republic of Mozambique is experiencing a significant social and economic change and needs an updated informative base to allow policy-makers to found their decision on reliable and comparable data. The fast development of the Non Observed Economy (NOE) was one of the most important consequences of the transformation of the Mozambican economy. The Italian support Programme to the Mozambique National Statistical System , started in 2004, provided technical assistance for improving the quality of statistics for the Mozambican government according to best practices and international standards. One of the most interesting component of the project was the definition of a methodology for the analysis of the NOE and the provision of a first estimate of the phenomenon through a survey carried out at national level. Within the consortium, led by ICstat, Istat was responsible for the component, with the technical support of experts from INE Mozambique and INE Portugal . The NOE, as defined in the OECD Handbook for Measuring the Non Observed Economy, is one of the most relevant issues to be tackled in order to guarantee a correct comparison of the National Accounts variables and the exhaustiveness of National Accounts estimates, according to the System of National Accounts defined by the UN Handbook (SNA93), nowadays adopted by the majority of countries, that allows the correct comparison of their economic results. At international level there has been considerable progress towards the harmonization of statistical concepts and methods, through the adoption by international organizations of common standards and recommendations: 15th International Conference of Labour Statistics – Recommendation on employment statistics in the informal sector (1993); 3rd Revision of the United Nation’s System of National Accounts, which indicated how the informal sector should be treated in the accounts; the OECD Handbook, which also draws on the SNA93 for the terms used in the definition of NOE. Statistical information about the informal sector and small enterprises in Mozambique is still very sketchy in spite of their major economic significance: the informal sector is in fact directly linked to the main objectives of development (increased production, job creation, combating poverty). Therefore, strong attention has been paid to this component and in particular to the implementation of a specific survey for gathering the information necessary for the assessment of the methodology and the estimation of the sector. In this sense, the main commitment of the project was to strengthen INE Mozambique’s statistical capacity, in order both to approach the NOE sector according to international standards and to carry out, for the first time, a survey based on sound and exhaustive methodology. The aim of this handbook is twofold: • To focus on the experience derived from the project’s component, describing the strategies adopted and the steps implemented to define an ad-hoc methodology within the social and economic contextual factors which takes into account the national statistical environment and the international statistical framework (international standards, assessment of the Informal Sector in Mozambique, questionnaire, survey techniques and final estimations). The methods and techniques presented for approaching the informal sector study could represent a reference for future analysis on this phenomenon and for repeating similar surveys. • To present the results of the survey with the main information on the sector and a first analysis of it. Although the Mozambique reality represents a peculiar case, the value added of the project’s component lies in the fact that the experiences gained and the good practices adopted can be a reference model for those countries that are currently experiencing a development phase with socio-economic features comparable with those of the Mozambican economy. The results of the survey are useful for more exhaustive estimations for National Accounts and, at the same time, represent a benchmark of social evaluation for planning poverty reduction strategies (PARPA). Moreover, with this survey INE Mozambique has analysed the agricultural production (in most cases represented by “production for auto-consumption”), often coming from secondary activities of households which are located in the urban area and that, as main activity, conduct extra-agricultural activities

Metodologia - O Sector Informal em Moçambique: Resultados do Primeiro Inquérito Nacional (2005)

The Republic of Mozambique is experiencing a significant social and economic change and needs an updated informative base to allow policy-makers to found their decision on reliable and comparable data. The fast development of the Non Observed Economy (NOE) was one of the most important consequences of the transformation of the Mozambican economy. The Italian support Programme to the Mozambique National Statistical System , started in 2004, provided technical assistance for improving the quality of statistics for the Mozambican government according to best practices and international standards. One of the most interesting component of the project was the definition of a methodology for the analysis of the NOE and the provision of a first estimate of the phenomenon through a survey carried out at national level. Within the consortium, led by ICstat, Istat was responsible for the component, with the technical support of experts from INE Mozambique and INE Portugal . The NOE, as defined in the OECD Handbook for Measuring the Non Observed Economy, is one of the most relevant issues to be tackled in order to guarantee a correct comparison of the National Accounts variables and the exhaustiveness of National Accounts estimates, according to the System of National Accounts defined by the UN Handbook (SNA93), nowadays adopted by the majority of countries, that allows the correct comparison of their economic results. At international level there has been considerable progress towards the harmonization of statistical concepts and methods, through the adoption by international organizations of common standards and recommendations: 15th International Conference of Labour Statistics – Recommendation on employment statistics in the informal sector (1993); 3rd Revision of the United Nation’s System of National Accounts, which indicated how the informal sector should be treated in the accounts; the OECD Handbook, which also draws on the SNA93 for the terms used in the definition of NOE. Statistical information about the informal sector and small enterprises in Mozambique is still very sketchy in spite of their major economic significance: the informal sector is in fact directly linked to the main objectives of development (increased production, job creation, combating poverty). Therefore, strong attention has been paid to this component and in particular to the implementation of a specific survey for gathering the information necessary for the assessment of the methodology and the estimation of the sector. In this sense, the main commitment of the project was to strengthen INE Mozambique’s statistical capacity, in order both to approach the NOE sector according to international standards and to carry out, for the first time, a survey based on sound and exhaustive methodology. The aim of this handbook is twofold: • To focus on the experience derived from the project’s component, describing the strategies adopted and the steps implemented to define an ad-hoc methodology within the social and economic contextual factors which takes into account the national statistical environment and the international statistical framework (international standards, assessment of the Informal Sector in Mozambique, questionnaire, survey techniques and final estimations). The methods and techniques presented for approaching the informal sector study could represent a reference for future analysis on this phenomenon and for repeating similar surveys. • To present the results of the survey with the main information on the sector and a first analysis of it. Although the Mozambique reality represents a peculiar case, the value added of the project’s component lies in the fact that the experiences gained and the good practices adopted can be a reference model for those countries that are currently experiencing a development phase with socio-economic features comparable with those of the Mozambican economy. The results of the survey are useful for more exhaustive estimations for National Accounts and, at the same time, represent a benchmark of social evaluation for planning poverty reduction strategies (PARPA). Moreover, with this survey INE Mozambique has analysed the agricultural production (in most cases represented by “production for auto-consumption”), often coming from secondary activities of households which are located in the urban area and that, as main activity, conduct extra-agricultural activities

Loss of Ambra1 promotes melanoma growth and invasion

Melanoma is the deadliest skin cancer. Despite improvements in the understanding of the molecular mechanisms underlying melanoma biology and in defining new curative strategies, the therapeutic needs for this disease have not yet been fulfilled. Herein, we provide evidence that the Activating Molecule in Beclin-1-Regulated Autophagy (Ambra1) contributes to melanoma development. Indeed, we show that Ambra1 deficiency confers accelerated tumor growth and decreased overall survival in Braf/Pten-mutated mouse models of melanoma. Also, we demonstrate that Ambra1 deletion promotes melanoma aggressiveness and metastasis by increasing cell motility/invasion and activating an EMT-like process. Moreover, we show that Ambra1 deficiency in melanoma impacts extracellular matrix remodeling and induces hyperactivation of the focal adhesion kinase 1 (FAK1) signaling, whose inhibition is able to reduce cell invasion and melanoma growth. Overall, our findings identify a function for AMBRA1 as tumor suppressor in melanoma, proposing FAK1 inhibition as a therapeutic strategy for AMBRA1 low-expressing melanoma. The absence of scaffold protein Ambra1 leads to hyperproliferation and growth in mouse models. Here the authors show that Ambra1 deficiency accelerates melanoma growth and increases metastasis in mouse models of melanoma through FAK1 hyperactivation

AMBRA1 regulates cyclin D to guard S-phase entry and genomic integrity

Mammalian development, adult tissue homeostasis and the avoidance of severe diseases including cancer require a properly orchestrated cell cycle, as well as error-free genome maintenance. The key cell-fate decision to replicate the genome is controlled by two major signalling pathways that act in parallel-the MYC pathway and the cyclin D-cyclin-dependent kinase (CDK)-retinoblastoma protein (RB) pathway(1,2). Both MYC and the cyclin D-CDK-RB axis are commonly deregulated in cancer, and this is associated with increased genomic instability. The autophagic tumour-suppressor protein AMBRA1 has been linked to the control of cell proliferation, but the underlying molecular mechanisms remain poorly understood. Here we show that AMBRA1 is an upstream master regulator of the transition from G1 to S phase and thereby prevents replication stress. Using a combination of cell and molecular approaches and in vivo models, we reveal that AMBRA1 regulates the abundance of D-type cyclins by mediating their degradation. Furthermore, by controlling the transition from G1 to S phase, AMBRA1 helps to maintain genomic integrity during DNA replication, which counteracts developmental abnormalities and tumour growth. Finally, we identify the CHK1 kinase as a potential therapeutic target in AMBRA1-deficient tumours. These results advance our understanding of the control of replication-phase entry and genomic integrity, and identify the AMBRA1-cyclin D pathway as a crucial cell-cycle-regulatory mechanism that is deeply interconnected with genomic stability in embryonic development and tumorigenesis

Inferenza bayesana non parametrica mediante wavelets

Dottorato di ricerca in statistica metodologica. 10 ciclo. A.a. 1994-97Consiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7 Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Partial identification in statistical matching with misclassification

The main target of statistical matching is to make inference on variables observed in different sources by using information on common variables. The partial information generally implies that the model is not identifiable. The aim of this paper is to study the case when common variables are affected by a misclassification. The partially identifiable region, that is the class of probabilities extending the conditional probabilities obtained by the information in different sources, is determined. These regions are determined in the general case and under some specific restrictions on the misclassification mechanism. An application to real data is used to show in practice the results achieved in the paper