Fractal geometry of critical Potts clusters

Numerical simulations on the total mass, the numbers of bonds on the hull, external perimeter, singly connected bonds and gates into large fjords of the Fortuin-Kasteleyn clusters for two-dimensional q-state Potts models at criticality are presented. The data are found consistent with the recently derived corrections-to-scaling theory. However, the approach to the asymptotic region is slow, and the present range of the data does not allow a unique identification of the exact correction exponentsComment: 7 pages, 8 figures, Late

Interface dynamics and kinetic roughening in fractals

We consider the dynamics and kinetic roughening of single-valued interfaces in two-dimensional fractal media. Assuming that the local height difference distribution function of the fronts obeys Levý statistics with a well-defined power-law decay exponent, we derive analytic expressions for the local scaling exponents. We also show that the kinetic roughening of the interfaces displays anomalous scaling and multiscaling in the relevant correlation functions. For invasion percolation models, the exponents can be obtained from the fractal geometry of percolation clusters. Our predictions are in excellent agreement with numerical simulations.Peer reviewe

Studies Needed to Address Public Health Challenges of the 2009 H1N1 Influenza Pandemic: Insights from Modeling

In light of the 2009 influenza pandemic and potential future pandemics, Maria Van Kerkhove and colleagues anticipate six public health challenges and the data needed to support sound public health decision making.The authors acknowledge support from the Bill & Melinda Gates Foundation (MDVK, CF, NMF); Royal Society (CF); Medical Research Council (MDVK, CF, PJW, NMF); EU FP7 programme (NMF); UK Health Protection Agency (PJW); US National Institutes of Health Models of Infectious Disease Agent Study program through cooperative agreement 1U54GM088588 (ML); NIH Director's Pioneer Award, DP1-OD000490-01 (DS); EU FP7 grant EMPERIE 223498 (DS); the Wellcome Trust (DS); 3R01TW008246-01S1 from Fogerty International Center and RAPIDD program from Fogerty International Center with the Science & Technology Directorate, Department of Homeland Security (SR); and the Institut de Veille Sanitaire Sanitaire funded by the French Ministry of Health (J-CD). The funders played no role in the decision to submit the article or in its preparation

Motion of flux transfer events: a test of the Cooling model

The simple model of reconnected field line motion developed by Cooling et al. (2001) has been used in several recent case studies to explain the motion of flux transfer events across the magnetopause. We examine 213 FTEs observed by all four Cluster spacecraft under a variety of IMF conditions between November 2002 and June 2003, when the spacecraft tetrahedron separation was ~5000 km. Observed velocities were calculated from multi-spacecraft timing analysis, and compared with the velocities predicted by the Cooling model in order to check the validity of the model. After excluding three categories of FTEs (events with poorly defined velocities, a significant velocity component out of the magnetopause surface, or a scale size of less than 5000 km), we were left with a sample of 118 events. 78% of these events were consistent in both direction of motion and speed with one of the two model de Hoffmann-Teller (dHT) velocities calculated from the Cooling model (to within 30° and a factor of two in the speed). We also examined the plasma signatures of several magnetosheath FTEs; the electron signatures confirm the hemisphere of connection indicated by the model in most cases. This indicates that although the model is a simple one, it is a useful tool for identifying the source regions of FTEs

”Kansankollektiivin perustaminen on kuin taivaaseen meneminen”:Kiinan sisällissota ja kommunistisen Kiinan alkuvaiheet keskikoulun ja peruskoulun historian oppikirjoissa 1966–1999

Tiivistelmä. Tutkimus tarkastelee vuosina 1966–1999 julkaistujen keskikoulun ja peruskoulun historian oppikirjojen kuvausta Kiinan 1920-luvun lopulla alkaneesta sisällissodasta ja vuonna 1949 perustetun kansantasavallan alkuvaiheista 1960-luvun alkupuolelle saakka. Tutkimuksen keskeisenä tavoitteena on tarkastella, miksi kuvaus oli juuri tietynlainen, ja toisaalta vertailla ja analysoida aineistossa tapahtunutta kuvauksen muutosta. Tutkimuksen menetelminä toimivat sisällönanalyysi ja vertaileva metodi. Tutkimus jakaantuu temaattisesti kolmeen osioon: Kiinan sisällissodan kuvauksen tarkasteluun, kansantasavallan perustamisen ja suurta harppausta edeltäneiden uudistusten kuvauksen tarkasteluun sekä suuren harppauksen kuvauksen tarkasteluun. Aineisto jakaantuu suomettumisen aikaisiin oppikirjoihin ja suomettumisen jälkeisiin oppikirjoihin siten, että ensimmäiseen osaan on sisällytetty keskikoulun oppikirjat ja peruskoulun ensimmäiset oppikirjasarjat, ja toiseen osaan Kekkosen ajan ja vuoden 1985 opetussuunnitelman jälkeiset uudet kirjasarjat. Tutkimuksessa havaittiin, että oppikirjojen kuvaukset olivat voimakkaasti sidoksissa aikansa poliittiseen ympäristöön, poliittiseen korrektiuteen ja kouluhallituksen asettamiin vaatimuksiin. Kommunistista Kiinaa käsiteltiin kirjoissa kaikkein eniten 1970-luvun peruskoulun oppikirjoissa, joissa kommunisteja ja sosialismia myös ylistettiin vuolaimmin. Muutoksen jyrkkyyttä kuvastaa se, että 1960-luvulla julkaistuun keskikoulun oppikirjaan, jossa Kiinan kommunisteja ei kuvattu kovinkaan suopeasti, ilmestyi 1970-luvun alun painokseen voimakkaasti kommunisteja ja sosialismia ylistänyttä tekstiä, samalla kun kriittiseksi tulkittavissa olevat kohdat oli poistettu. Oppikirjat pyrkivät enimmäkseen noudattamaan valtion ulkopoliittista linjaa, mutta enemmän niiden laatimiseen vaikutti sisäpoliittinen paine, kirjatarkastukset ja itsesensuuri. Tätä kuvastaa se, että vaikka 1980-luvulla Suomen ulkopolitiikan viralliset linjaukset säilyivät pitkälti samana, kutistui kirjojen Kiinan sisällissotaa ja kansantasavallan vaiheita käsitellyt sisältö huomattavasti, ja kuvaus muuttui selkeästi neutraalimpaan suuntaan. Tutkittavan ajanjakson lopulla kuvaus keskittyi jo enemmän Kiinan epäkohtiin, eikä sosialismin ylistämistä katsottu enää tarpeelliseksi. Kommunistista Kiinaa voitiin kuitenkin myös kritisoida jopa 1970-luvun kirjoissa. Terävämpään kritiikkiin tukea haettiin Neuvostoliiton linjauksista, eikä kritiikki kohdistunut missään vaiheessa sosialismiin, vain korkeintaan Kiinan tapaan soveltaa sitä. Aineistosta olikin havaittavissa, että ylistävän kuvauksen varsinaisena kohteena oli sosialismi, Kiinan toimiessa vain ylistyksen välineenä. Kirjojen kuvauksissa Kiinan kansatasavallan johto saattoi tehdä huonoja ratkaisuja, mutta loppujen lopuksi sosialismiin siirtyminen oli aina positiivinen asia, kunhan radikaaleimpia linjauksia tarkistettiin parempaan suuntaan

Effect of weight loss, with or without exercise, on body composition and sex hormones in postmenopausal women: the SHAPE-2 trial

Introduction Physical inactivity and overweight are risk factors for postmenopausal breast cancer. The effect of physical activity may be partially mediated by concordant weight loss. We studied the effect on serum sex hormones, which are known to be associated with postmenopausal breast cancer risk, that is attributable to exercise by comparing randomly obtained equivalent weight loss by following a hypocaloric diet only or mainly by exercise. Methods Overweight, insufficiently active women were randomised to a diet (N = 97), mainly exercise (N = 98) or control group (N = 48). The goal of both interventions was to achieve 5–6 kg of weight loss by following a calorie-restricted diet or an intensive exercise programme combined with only a small caloric restriction. Primary outcomes after 16 weeks were serum sex hormones and sex hormone-binding globulin (SHBG). Body fat and lean mass were measured by dual-energy X-ray absorptiometry. Results Both the diet (−4.9 kg) and mainly exercise (−5.5 kg) groups achieved the target weight loss. Loss of body fat was significantly greater with exercise versus diet (difference −1.4 kg, P < 0.001). In the mainly exercise arm, the reduction in free testosterone was statistically significantly greater than that of the diet arm (treatment effect ratio [TER] 0.92, P = 0.043), and the results were suggestive of a difference for androstenedione (TER 0.90, P = 0.064) and SHBG (TER 1.05, P = 0.070). Compared with the control arm, beneficial effects were seen with both interventions, diet and mainly exercise, respectively, on oestradiol (TER 0.86, P = 0.025; TER 0.83, P = 0.007), free oestradiol (TER 0.80, P = 0.002; TER 0.77, P < 0.001), SHBG (TER 1.14; TER 1.21, both P < 0.001) and free testosterone (TER 0.91, P = 0.069; TER = 0.84, P = 0.001). After adjustment for changes in body fat, intervention effects attenuated or disappeared. Conclusions Weight loss with both interventions resulted in favourable effects on serum sex hormones, which have been shown to be associated with a decrease in postmenopausal breast cancer risk. Weight loss induced mainly by exercise additionally resulted in maintenance of lean mass, greater fitness, greater fat loss and a larger effect on (some) sex hormones. The greater fat loss likely explains the observed larger effects on sex hormone

A Conserved PHD Finger Protein and Endogenous RNAi Modulate Insulin Signaling in Caenorhabditis elegans

Insulin signaling has a profound effect on longevity and the oxidative stress resistance of animals. Inhibition of insulin signaling results in the activation of DAF-16/FOXO and SKN-1/Nrf transcription factors and increased animal fitness. By studying the biological functions of the endogenous RNA interference factor RDE-4 and conserved PHD zinc finger protein ZFP-1 (AF10), which regulate overlapping sets of genes in Caenorhabditis elegans, we identified an important role for these factors in the negative modulation of transcription of the insulin/PI3 signaling-dependent kinase PDK-1. Consistently, increased expression of pdk-1 in zfp-1 and rde-4 mutants contributed to their reduced lifespan and sensitivity to oxidative stress and pathogens due to the reduction in the expression of DAF-16 and SKN-1 targets. We found that the function of ZFP-1 in modulating pdk-1 transcription was important for the extended lifespan of the age-1(hx546) reduction-of-function PI3 kinase mutant, since the lifespan of the age-1; zfp-1 double mutant strain was significantly shorter compared to age-1(hx546). We further demonstrate that overexpression of ZFP-1 caused an increased resistance to oxidative stress in a DAF-16–dependent manner. Our findings suggest that epigenetic regulation of key upstream signaling components in signal transduction pathways through chromatin and RNAi may have a large impact on the outcome of signaling and expression of numerous downstream genes.Leukemia & Lymphoma Society of America (3260-07 Special Fellow Award)Arnold and Mabel Beckman Foundation (Young Investigator Award)United States. National Institutes of Health (Director's New Innovator Award (1 DP2 OD006412-01))United States. National Institutes of Health (grant GM66269)modENCODE (grant U01 HG004270)United States. National Institutes of Health (training grant 5T32 GM07088-34