Fixed-domain asymptotic properties of tapered maximum likelihood estimators

When the spatial sample size is extremely large, which occurs in many environmental and ecological studies, operations on the large covariance matrix are a numerical challenge. Covariance tapering is a technique to alleviate the numerical challenges. Under the assumption that data are collected along a line in a bounded region, we investigate how the tapering affects the asymptotic efficiency of the maximum likelihood estimator (MLE) for the microergodic parameter in the Mat\'ern covariance function by establishing the fixed-domain asymptotic distribution of the exact MLE and that of the tapered MLE. Our results imply that, under some conditions on the taper, the tapered MLE is asymptotically as efficient as the true MLE for the microergodic parameter in the Mat\'ern model.Comment: Published in at http://dx.doi.org/10.1214/08-AOS676 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Occurrence of human papillomaviruses (HPV) types in HPV related cancer and in the genital and oral tracts of young adults

Human papillomavirus (HPV) is associated to cancer of the uterine cervix, the third most common cancer among women, but also to head and neck squamous cell carcinoma (HNSCC), the sixth most common type of cancer in the world. HPV occurs in most cervical cancer (CC). In HNSCC, HPV is most frequently observed in oropharyngeal squamous cell carcinoma (OSCC) where tonsillar squamous cell carcinoma (TSCC) and the base of tongue account for 70-80% of the cases. It has also been shown that OSCC has increased in many Western Countries and we have shown HPV to be responsible for the increase of TSCC in Stockholm. In recent years, two vaccines were introduced against HPV, Gardasil (Merck) and Cevarix (GSK), both efficient against infection with HPV type 16 and 18 and Gardasil against HPV 6 and 11 as well, and these will change the prevalence of HPV types at different sites. The aim of this thesis was to investigate the role of HPV in the increase of tongue base cancer in the Stockholm. In addition, we wanted to obtain different base lines for the prevalence of different HPV types for cervical cancer and in the genital and oral tracts in young adults in the Stockholm region. Finally we wanted to compare different HPV E6 variants in TSCC and CC as well as in cervical samples (CS) from healthy young women. The first paper showed that the prevalence of HPV in base of tongue cancer in Stockholm increased from 58% in 1998-1999 to 84% 2006-2007 with HPV 16 dominating (86%). The parallel increase in incidence and proportion of HPV positive base of tongue cancer suggests HPV may contribute to this increase similar to that previously shown for TSCC. The second paper showed a very high prevalence of HPV with 92.9% in all uterine cervix cancer cases, with 93.3% and 91.4 % in SCC and ADC, respectively. All HPV positive cases harbored HR types, either alone or as multiple infections. HPV 16 and 18 dominated, followed by HPV 33, 31, 45 and 56, in cervical cancer in the Stockholm region. Public HPV vaccination should inhibit a large proportion of HPV 16 and 18 positive tumors. The third paper revealed a high HPV prevalence in 544 analyzed cervical samples from nonvaccinated young women aged 16-23 years of age and 70% were positive for HPV and 62% were positive for HR-HPV types. Over a third (34.7%) of the women was infected with HPV 16 followed by HR-HPV types 51, 18, 52 and 73. The prevalence of HPV, as well as HR-HPV infection appeared to increase with age in women aged 17 – 21y, and then decrease. The data indicates that HPV vaccination in an early age can prevent HPV 16 and 18 infections and demonstrates the need for further monitoring of the prevalence of HR-HPV types. The fourth paper showed that 9.3% (9.2% for women and 9.8% for men) of the 483 oral samples from young adults were HPV-positive, with 7.2% being positive for HR-HPV types. HPV 16 was the most common (31%) followed by HPV 59 and HPV 51. Among these 174 women that were tested both for genital and oral HPV infection, oral infection was more frequent in women with (17.1%) as compared to those without (4.4%) genital infection (p=0.043) and there was a high HPV type concordance between the oral and genital locations. The fifth paper showed several patterns of HPV 16 E6 with the HPV E6 variant R10G was relatively common (19%) in TSCC, absent in CC and infrequent (4%) in CS, indicating significant differences of HPV 16 variants in TSCC compared to CC and CS which has not been observed before. Furthermore, the well-known L83V variant was very common in TSCC (40%) as it was in CC (31%) and CS (29%). The majority of HPV 16 (>90%) belonged to the European phylogenetic lineage and its derivatives. No significant relation between R10G variant and survival of TSCC patients was observed. In conclusion, we have demonstrated that HPV infection may play a role for the increase in base of tongue cancer, and HPV 16 and 18 are highly prevalent in CC and CS. HPV 16 is frequently found in oral samples indicates that HPV vaccination will potentially be useful to combat some of these tumors. Finally, we have shown differences in HPV 16 E6 variants between the TSCC and CC sites

STATE-RESOLVED QUENCHING DYNAMICS IN COLLISIONS OF VIBRATIONALLY EXCITED MOLECULES

The collisional relaxation of highly excited molecules plays a very important role in many chemistry processes. The work presented in this thesis studies the collisional quenching dynamics of highly vibrationally excited molecules using high–resolution transient IR absorption spectroscopy. This work investigates “weak” (small energy transfer) and “strong” (large energy transfer) collisions between donor and bath molecules. The experimental results illustrate how the properties of donor molecules influence the collisional energy transfer. These properties include the molecular structure, internal energy, state density. In several weak collision studies, this thesis studies the vibration–rotation/translation pathway for pyrazine/DCl, pyrazine/CO2 with different internal energies and for three excited alkylated pyridine molecules/CO2 systems. A single–exponential rotational distribution and J–dependent translational energy distributions of scattered DCl molecules are observed. For CO2 collisions, the scattered CO2 has a biexponential rotational distribution and J–dependent translational energy distributions for all collision pairs. Recoil velocities scale with product angular momenta. The observed collision rates for these collision pairs match Lennard–Jones rates. The full energy transfer distribution for these pairs is determined by combining data for weak and strong collisions. Lowering the internal energy of donor molecules reduces the amount of rotational and translational energy transfer to CO2. Reducing the internal energy of pyrazine decreases the probabilities of strong collision and increases the probabilities of weak collision. The average energy transfer reduces by ∼ 50% when the internal energy is decreased by only 15%. The collision rates are independent on the internal energy for these systems. Methylation of donor molecules decreases the magnitude of V—RT energy transfer. The collision results are affected by the number of methyl–groups, and not by the position of the group. Increasing the number of methyl groups increases the ratio of the measured collision rate to the Lennard–Jones collision rate. In the strong collision studies, the effects of alkylation and internal energy are studied. In collisions with alkylated pyridine donors with E ∼ 39000 cm−1, CO2 molecules gain less energy from alkylpyridine than from pyridine. The alkylated donors undergo strong collisions with CO2 via a less repulsive part of the intermolecular potential compared to pyridine. For azulene/CO2 collisions with two different internal energies, scattered CO2 molecules gain double the amount of rotational and translational energy when the azulene energy is doubled. The rate of strong collisions increases four times when the internal energy is doubled

Review of Introduction to Cognitive Pragmatics

This article reviews the book—Introduction to Cognitive Pragmatics written by Klaus-Uwe Panther. The book is a synthetic attempt to blend a cognitive linguistic approach to language in use from contemporary pragmatics. Although a few works on this reconciled filed have been published in the past 30 years, the term Cognitive Pragmatics is not well established in linguistic community yet (Schimid, 2012). In this vein, this newly published book makes a few steps forward on the road to an interface study approach both on cognitive linguistics and pragmatics. This review introduces and analyzes the main content of the book as well as providing a critical comment

COMPLEX FORMATION BY ALPHA-LACTALBUMIN AND POLYSACCHARIDE COPOLYMERS

Colloidal delivery systems, such as surfactant micelles, emulsions, liposomes, and nanoparticles, are widely used in food and pharmaceuticals to improve the dispersion of poorly-soluble ingredients or modify their bioaccessibility within the body. As a delivery system for medical- and health-relevant bioactive components, surfactant micelles have potential toxicity due to the disruption of cell membranes and interference with cell membrane transporters. Complexes formed among proteins and polysaccharides, as renewable biopolymers, are drawing attention for their potential application in the food, pharmaceutical, and cosmetic industries due to their non-toxicity and higher potential for rapid biodegradation

Formal and Informal Care: An Empirical Bayesian Analysis Using the Two-Part Model

Informal care provided to the elderly by their children is proposed as a less expensive alternative to institutional long-term care. This paper explores how the elderly\u27s consumption of medical care changes in response to changes in the informal care they receive from their children. Many earlier studies have ignored both the endogeneity of informal care and the complicated nature of health care utilization data. This paper develops a two-part model with informal care treated as an endogenous regressor and imposes exclusion restrictions on the selection process. The model is fitted using the Bayesian Markov Chain Monte Carlo (MCMC) methods, in particular the Gibbs sampler and the Metropolis-Hasting algorithm. The average treatment effects and the distributions of the treatment effects are obtained via posterior simulation. The results indicate that informal care provides a substitute for nursing home care and hospital inpatient care, but it does not affect paid home health care on average. The treatment effects are heterogeneous. The largest substitution effects occur for nursing home and hospital inpatient care at the intensive margin. The policy analysis suggests that informal care policies targeting the group that incurs the largest substitution effect may help to reduce government spending on Medicaid and Medicare