My research interests lie broadly in statistical methods applied to life and social sciences. In particular, I am interested in robust and nonparametric statistics, including quantile regression. I have developed methods to estimate quantiles of conditional distributions when data are clustered. Linear Quantile Mixed Models (Geraci and Bottai 2014, Statistics and Computing; Geraci 2014, Journal of Statistical Software), which stem from my PhD work, have been have been used by researchers in biostatistics, public health, medicine, marine biology, ophthalmology, environmental science, psychology, anesthesiology, finance, linguistic and lexicography. Some applications are referenced below. These studies showed that LQMMs represent a flexible and robust tool that complements the well-known linear mixed-effects models. See my software page for my R packages lqmm and Qtools.
I have also worked on semiparametric regression, missing data, survey methodology, multivariate analysis, and spatial statistics. My present and past collaborations include studies in child health, in particular on cancer epidemiology and physical activity using accelerometry, gastroenterology and radiology.
I have some MSc and PhD projects available, mostly related to quantile methods but also methods for missing data, analysis of complex survey data, and semiparametric regression. If you want to know more, you can email me or drop a message here. Here’s a sample of past and current projects
- Transformations to additivity for binary response data and quantile regression for bounded outcomes (MSc)
- Spectral and fractal analyses of accelerometer data (MSc)
- Quantile inference for extreme value and risk assessment in child health research (PhD)
Applications of LQMM
- , , . Energetic and ecological constraints on population density of reef fishes. Proceedings of the Royal Society B. 2016; 283: 20152186.
- Basile M, Valerio F, Balestrieri R, et al. Patchiness of forest landscape can predict species distribution better than abundance: the case of a forest-dwelling passerine, the short-toed treecreeper, in central Italy. PeerJ. 2016;4:e2398.
- Beets MW, Weaver RG, Turner-McGrievy G, et al. Physical activity outcomes in afterschool programs: A group randomized controlled trial. Prev Med. 2016;90:207-15.
- Beets MW, Weaver RG, Turner-McGrievy G, et al. Are we there yet? Compliance with physical activity standards in YMCA afterschool programs. Childhood Obesity. 2015; DOI: http://dx.doi.org/10.1089/chi.2015.0223.
- Bellavia A, Hauser R, Seely EW, et al. Urinary phthalate metabolite concentrations and maternal weight during early pregnancy. International Journal of Hygiene and Environmental Health. 2017; DOI: https://doi.org/10.1016/j.ijheh.2017.09.005.
- Benedetti A, Platt R, Atherton J. Generalized linear mixed models for binary data: Are matching results from penalized quasi-likelihood and numerical integration less biased? PLoS ONE. 2014; 9(1): e84601.
- , ,
- Brazendale K, Beets MW, Weaver RG, et al. Children’s moderate to vigorous physical activity attending summer day camps. American Journal of Preventive Medicine. 2017; DOI: http://dx.doi.org/10.1016/j.amepre.2017.01.019.
- Caitlin A. Modeling and forecasting the influence of current and future climate on Eastern North American spruce-fir (Picea-Abies) forests” (2016). Electronic Theses and Dissertations. 2562. http://digitalcommons.library.umaine.edu/etd/2562
- Calkins KL, Lesko CR, Chander G, et al. Influence of injection drug use-related HIV acquisition on CD4 response to first antiretroviral therapy regimen among virally suppressed individuals. JAIDS Journal of Acquired Immune Deficiency Syndromes. 2018;77(3):317-324.
- Cambiè G, Pantin JR, Lincoln H, et al. Diversity of fishing métier use can affect incomes and costs in small-scale fisheries. Canadian Journal of Fisheries and Aquatic Sciences. 2017; DOI: http://dx.doi.org/10.1139/cjfas-2016-0367.
- Cassidy M, Rydberg J. Analyzing variation in prior record penalties across conviction offenses. Crime and Delinquency. 2017; DOI: https://doi.org/10.1177/0011128717693215.
- Čelar A, Tafaj E, Graf A, and Lettner S. (2018). Association of anterior and posterior occlusal planes with different Angle and skeletal classes in permanent dentitions. Journal of Orofacial Orthopedics / Fortschritte der Kieferorthopädie. https://doi.org/10.1007/s00056-018-0139-z.
- Chander G, Hutton HE, Lau B, et al. Brief intervention decreases drinking frequency in HIV-infected, heavy drinking women: Results of a randomized controlled trial. JAIDS. 2015;70(2):137-45.
- Costanzo A. The Effect of M@tabel on Italian Students’ Performances: A Quantile Regression Approach. Procedia – Social and Behavioral Sciences. 2015;197:236-44.
- Degerud E, Løland KH, Nygård O, et al. Vitamin D status was not associated with `one-year’ progression of coronary artery disease, assessed by coronary angiography in statin-treated patients. Eur J Prev Cardiol. 2015;22(5):594-602.
- Dhayat NA, Dick B, Frey BM, et al. Androgen biosynthesis during minipuberty favors the backdoor pathway over the classic pathway: insights into enzyme activities and steroid fluxes in healthy infants during the first year of life from the urinary steroid metabolome. The Journal of Steroid Biochemistry and Molecular Biology. 2016; DOI: http://dx.doi.org/10.1016/j.jsbmb.2016.07.009.
- Duffy L, Olson R, Lennert-Cody C, et al. Foraging ecology of silky sharks, Carcharhinus falciformis, captured by the tuna purse-seine fishery in the eastern Pacific Ocean. Mar Biol. 2015;162(3):571-593.
- Feiveson A, Glenn NL. Modeling longitudinal data containing non-normal within subject errors. NASA Johnson Space Center; Houston, TX, United States. Available at http://ntrs.nasa.gov/search.jsp?R=20140003930.
- Fornaroli R, Cabrini R, Sartori L, et al. Predicting the constraint effect of environmental characteristics on macroinvertebrate density and diversity using quantile regression mixed model. Hydrobiologia. 2015;742(1):153-167.
- Gouin M, Flamant C, Gascoin G, et al. The Association of Urbanicity with Cognitive Development at Five Years of Age in Preterm Children. PLoS ONE. 2015;10(7):e0131749.
- Grace JB, Adler PB, Harpole WS, et al. Causal networks clarify productivity–richness interrelations, bivariate plots do not. Functional Ecology. 2014;28(4):787–798.
- Howard LM, Fan R, Zhu Y, et al. Nasopharyngeal pneumococcal density is associated with viral activity but not with use of improved stoves among young Andean children. Open Forum Infectious Diseases. 2017; DOI: https://doi.org/10.1093/ofid/ofx161.
- Inanoglu H, Jacobs M, Sickles RC. Analyzing bank efficiency: Are `too-big-to-fail’ banks efficient?, Measuring Economic Performance, Loughborough University, UK. March 2012.
- Kingwell RS and Xayavong V. How drought affects the financial characteristics of Australian farm businesses. Australian Journal of Agricultural and Resource Economics. 2016; DOI: http://dx.doi.org/10.1111/1467-8489.12195.
- Løland KH, Bleie Ø, Borgeraas H, et al. The association between progression of atherosclerosis and the methylated amino acids asymmetric dimethylarginine and trimethyllysine. PLoS ONE. 2013;8(5):e64774.
- Long JD, Mills JA, Leavitt BR, et al. Survival end points for Huntington disease trials prior to a motor diagnosis. JAMA Neurology. 2017; DOI: 10.1001/jamaneurol.2017.2107.
- Lu J, Li J, Helmlinger G, Al-Huniti N. Assessing QT/QTc interval prolongation with concentration-QT modeling for Phase I studies: impact of computational platforms, model structures and confidence interval calculation methods. Journal of Pharmacokinetics and Pharmacodynamics. 2018; DOI:10.1007/s10928-018-9582-0.
- Muir PR, Wallace CC, Done T, Aguirre JD. Limited scope for latitudinal extension of reef corals. Science. 2015;348(6239):1135-1138. DOI: http://dx.doi.org/10.1126/science.1259911.
- Ng SW, Howard AG, Wang HJ, et al. The physical activity transition among adults in China: 1991–2011. Obesity Reviews. 2014;15:27-36.
- Ouyang Y, Wang H, Su C, et al. Use of quantile regression to investigate changes in the body mass index distribution of Chinese adults aged 18-60 years: a longitudinal study. BMC Public Health. 2015;15(1):278. DOI: http://dx.doi.org/10.1186/s12889-015-1606-8.
- Pastpipatkul P, Boonyakunakorn P, Sriboonchitta S. Gravity Model of Trade with Linear Quantile Mixed Models Approach. In: Kreinovich V, Sriboonchitta S, Huynh V-N, editors. Robustness in Econometrics. Cham: Springer International Publishing; 2017. p. 561-74.
- Patel DE, Cumberland PM, Walters BC, et al. Study of optimal perimetric testing in children (OPTIC): Normative visual field values in children. Ophthalmology 2015;122(8):1711-1717.
- Piombo S. Multilevel analysis in household survey: An application to health condition data [Doctoral Dissertation]. Bologna: University of Bologna; 2013.
- Santoni G, Marengoni A, Calderón-Larrañaga A, et al. Defining health trajectories in older adults with five clinical indicators. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences. 2016; DOI: http://dx.doi.org/10.1093/gerona/glw204.
- Schuit E, Stock S, Rode L, et al. Effectiveness of progestogens to improve perinatal outcome in twin pregnancies: an individual participant data meta-analysis. BJOG. 2015; 122(1):27-37. (Commentary DOI: http://dx.doi.org/10.1111/1471-0528.13030).
- Tampucci D, Azzoni RS, Boracchi P, et al. Debris-covered glaciers as habitat for plant and arthropod species: Environmental framework and colonization patterns. Ecological Complexity. 2017;32(Part A):42-52.
- Ecology of active rock glaciers and surrounding landforms: climate, soil, plants and arthropods. Boreas. 2016; DOI: http://dx.doi.org/10.1111/bor.12219. , , , et al
- Thiébaut R. Reference curves for CD4 response to antiretroviral treatment in HIV-1 infected naïve patients. Conference on Retroviruses and Opportunistic Infections; 23-26 February 2015, Seattle, WA, United States. Available at http://www.croiconference.org/sites/default/files/posters-2015/569.pdf.
- Utnes ALG, Sorum V, Hulter N, et al. Growth phase-specific evolutionary benefits of natural transformation in Acinetobacter baylyi. ISME J. 2015; DOI: http://dx.doi.org/10.1038/ismej.2015.35.
- van Steenbergen HW, Tsonaka R, Huizinga TWJ, et al. Fatigue in rheumatoid arthritis; a persistent problem: a large longitudinal study. RMD Open. 2015; 1(1):1-9.