Brain Connectivity-Informed Regularization Methods for Regression

One of the challenging problems in brain imaging research is a principled incorporation of information from different imaging modalities. Frequently, each modality is analyzed separately using, for instance, dimensionality reduction techniques, which result in a loss of mutual information. We propose a novel regularization method to estimate the association between the brain structure features and a scalar outcome within the linear regression framework. Our regularization technique provides a principled approach to use external information from the structural brain connectivity and inform the estimation of the regression coefficients. Our proposal extends the classical Tikhonov regularization framework by defining a penalty term based on the structural connectivity-derived Laplacian matrix. Here, we address both theoretical and computational issues. The approach is first illustrated using simulated data and compared with other penalized regression methods. We then apply our regularization method to study the associations between the alcoholism phenotypes and brain cortical thickness using a diffusion imaging derived measure of structural connectivity. Using the proposed methodology in 148 young male subjects with a risk for alcoholism, we found a negative associations between cortical thickness and drinks per drinking day in bilateral caudal anterior cingulate cortex, left lateral OFC, and left precentral gyrus

Development of children’s hymenoptera venom allergy quality of life scale (CHVAQoLS)

BACKGROUND: Venom allergy is a rare but life-threatening disease and may have a considerable impact on the health-related quality of life (HRQoL) of patients, especially children. This paper presents development of the HRQoL scale for children and adolescents with Hymenoptera venom allergy (HVA). METHODS: The study sample consisted of 71 children, born between 1992 and 2000, who presented with a history of insect sting reaction when referred for consultation in the allergy center of Polish-American Children’s Hospital, Krakow, Poland, during the period from 2000 to 2010. The initial pool of 60 items - divided into 6 domains - was prepared. The items with intercorrelations higher than 0.7 were removed from each domain and then principal component analysis was conducted for each domain separately, to provide a one-dimensional subscale for each domain. Reliability of the subscales was assessed using Cronbach alpha coefficient in terms of Classical Test Theory and with rho coefficient in terms of Item Response Theory. The multidimensionality of the scale was tested using multi-trait scaling. RESULTS: Three to four items from each domain were subsequently selected to constitute six subscales. Rho coefficients for all the subscales reached 0.8, similar results were achieved with the Cronbach alpha coefficients. Multi-trait method showed that the majority of the items indicated stronger correlations with their own subscales than with other subscales, which proves that our constructed subscales measure different dimensions of HRQoL. CONCLUSIONS: The presented scale comprises high validity and reliability subscales measuring six dimensions of HRQoL related to Hymenoptera venom allergy in children and adolescents. Such information may be useful in everyday clinical practice

Increased diversification rates follow shifts to bisexuality in liverworts

Shifts in sexual systems are one of the key drivers of species diversification. In contrast to angiosperms, unisexuality prevails in bryophytes. Here, we test the hypotheses that bisexuality evolved from an ancestral unisexual condition and is a key innovation in liverworts. We investigate whether shifts in sexual systems influence diversification using hidden state speciation and extinction analysis (HiSSE). This new method compares the effects of the variable of interest to the best-fitting latent variable, yielding robust and conservative tests. We find that the transitions in sexual systems are significantly biased toward unisexuality, even though bisexuality is coupled with increased diversification. Sexual systems are strongly conserved deep within the liverwort tree but become much more labile toward the present. Bisexuality appears to be a key innovation in liverworts. Its effects on diversification are presumably mediated by the interplay of high fertilization rates, massive spore production and long-distance dispersal, which may separately or together have facilitated liverwort speciation, suppressed their extinction, or both. Importantly, shifts in liverwort sexual systems have the opposite effect when compared to angiosperms, leading to contrasting diversification patterns between the two groups. The high prevalence of unisexuality among liverworts suggests, however, a strong selection for sexual dimorphism

Meta-analysis of loci associated with age at natural menopause in African-American women

Age at menopause marks the end of a woman's reproductive life and its timing associates with risks for cancer, cardiovascular and bone disorders. GWAS and candidate gene studies conducted in women of European ancestry have identified 27 loci associated with age at menopause. The relevance of these loci to women of African ancestry has not been previously studied. We therefore sought to uncover additional menopause loci and investigate the relevance of European menopause loci by performing a GWAS meta-analysis in 6510 women with African ancestry derived from 11 studies across the USA. We did not identify any additional loci significantly associated with age at menopause in African Americans. We replicated the associations between six loci and age at menopause (P-value < 0.05): AMHR2, RHBLD2, PRIM1, HK3/UMC1, BRSK1/TMEM150B and MCM8. In addition, associations of 14 loci are directionally consistent with previous reports. We provide evidence that genetic variants influencing reproductive traits identified in European populations are also important in women of African ancestry residing in USA

Fundation of small calibre ammunition National Test Centre in Poland with NATO accreditation as an important step to the complete participation of the Polish armed forces into alliance structues

W procesie ratyfikacji dokumentów rangi STANAG dotyczących amunicji małokalibrowej, poszczególne kraje akceptują formułę postępowania która stanowi, że implementacja tych norm będzie nadzorowana przez organ NATO, a konkretnie podgrupę AC/225 (LG-3/SG/1), która ocenia czy nowe opracowania w zakresie konkretnego kalibru NATO spełniają wymagania i upoważnia je do używania symbolu zamienności NATO. Symbol ten będzie zastosowany jedynie do tych partii amunicji z bieżącej produkcji, które zostały zakwalifikowane zgodnie z procedurami badań (MOPI) dla danego kalibru. Testy kwalifikacyjne nowych opracowań i testy amunicji z bieżącej produkcji są przeprowadzane jedynie w Regionalnych Centrach Badawczych (RTC) NATO, podczas gdy testy amunicji po składowaniu mogą być przeprowadzane w Narodowych Centrach Badawczych (NTC). W artykule przedstawiono dotychczasowe działania Wojskowego Instytutu Technicznego Uzbrojenia w Zielonce na drodze do utworzenia Narodowego Centrum Badań Amunicji Strzeleckiej (NCBAS) oraz argumenty świadczące o ważności tego przedsięwzięcia.In ratifying STANAGs concern small calibre ammunition, nations accept that implementation of STANAGs will be managed by a NATO body, currently the sub-Group on Standard NATO: Small Arms Ammunition, AC/225 (LG-3 - SG/1), which will assess the compliance of candidate ammunition designs with the Technical Performance Specification in the STANAG, and will authorize the use of the NATO symbol of Interchange ability. This symbol will be used only on production lots of ammunition whose design has been ąualified in accordance with the procedures of Manual of Proof and Inspection (MOPI). The qualification and production acceptance tests are only conducted at NATO Regional Test Centre (RTC), while the surveillance tests may be conducted at NATO approved National Tests Centre (NTC). In this paper there is presented up to now activity of Military Institute of Armament Technology in Zielonka on the way to creating the National Test Centre of Small Calibre Ammunition and some arguments testifying about validity this undertaking

Investigations, analysis and assessment of certain aspects of thermo-mechanical and chemical resistance of graphite nozzles to action of combustion products of sustaining solid rocket propellant charges applied in propulsion systems of GROM missiles

W artykule przedstawiono pewne aspekty badania, analizy i oceny odporności termomechanicznej i chemicznej dysz grafitowych zbudowanych z wkładki pirografitowej oraz korpusu z grafitu polikrystalicznego, na działanie produktów spalania marszowego ładunku przeciwlotniczego pocisku rakietowego GROM. We wstępnej fazie badań wykonano analizę modelu spalania heterogenicznego paliwa rakietowego tworzącego ładunek marszowy układu napędowego pocisku GROM, w określonych warunkach pracy silnika rakietowego. Rzeczywistą odporność dysz na erozyjne działanie strumienia produktów spalania określano za pomocą diagnostycznego systemu radioskopowego czasu rzeczywistego poprzez porównanie zmian profilu przekroju kanału przelotowego dyszy, a zwłaszcza średnicy krytycznej kanału przed oraz po stacjonarnych badaniach spalaniem ładunków marszowych pocisku GROM w grubościennych komorach spalania.In this paper there are presented certain aspects of investigations, analyses and assessments dealing with thermo-mechanical and chemical resistance of nozzles composed of pyrographite insert and body made from polycrystalline graphite. The nozzles were considered in terms of their thermo-mechanical and chemical resistance against combustion products of sustaining propellant charge applied in propulsion system of antiaircraft missile GROM. In initial stage of investigations, it was conducted analysis of combustion model of heterogeneous rocket propellant of composition corresponding to composition of real sustaining propulsive charge of missile GROM, under assumed conditions of rocket motor operation. Real resistance of graphite nozzles against action of combustion products, was determined by means of real time radiography (RTR) on the basis of comparison of nozzle duct section profile changes before and after static firing tests with usage of GROM missile sustaining propellant charges inserted in thick-walled combustion chamber