University of Jyväskylä

About: University of Jyväskylä is a education organization based out in Jyvaskyla, Finland. It is known for research contribution in the topics: Population & Context (language use). The organization has 8066 authors who have published 25168 publications receiving 725033 citations. The organization is also known as: Jyväskylän yliopisto & Kasvatusopillinen korkeakoulu.

The closure of Pak1-dependent macropinosomes requires the phosphorylation of CtBP1/BARS.

Abstract: Membrane fission is an essential process in membrane trafficking and other cellular functions While many fissioning and trafficking steps are mediated by the large GTPase dynamin, some fission events are dynamin independent and involve C-terminal-binding protein-1/brefeldinA-ADP ribosylated substrate (CtBP1/BARS) To gain an insight into the molecular mechanisms of CtBP1/BARS in fission, we have studied the role of this protein in macropinocytosis, a dynamin-independent endocytic pathway that can be synchronously activated by growth factors Here, we show that upon activation of the epidermal growth factor receptor, CtBP1/BARS is (a) translocated to the macropinocytic cup and its surrounding membrane, (b) required for the fission of the macropinocytic cup and (c) phosphorylated on a specific serine that is a substrate for p21-activated kinase, with this phosphorylation being essential for the fission of the macropinocytic cup Importantly, we also show that CtBP1/BARS is required for macropinocytic internalization and infection of echovirus 1 These results provide an insight into the molecular mechanisms of CtBP1/BARS activation in membrane fissioning, and extend the relevance of CtBP1/BARS-induced fission to human viral infection

A Little Is Enough: Circumventing Defenses For Distributed Learning

Abstract: Distributed learning is central for large-scale training of deep-learning models. However, it is exposed to a security threat in which Byzantine participants can interrupt or control the learning process. Previous attack models assume that the rogue participants (a) are omniscient (know the data of all other participants), and (b) introduce large changes to the parameters. Accordingly, most defense mechanisms make a similar assumption and attempt to use statistically robust methods to identify and discard values whose reported gradients are far from the population mean. We observe that if the empirical variance between the gradients of workers is high enough, an attacker could take advantage of this and launch a non-omniscient attack that operates within the population variance. We show that the variance is indeed high enough even for simple datasets such as MNIST, allowing an attack that is not only undetected by existing defenses, but also uses their power against them, causing those defense mechanisms to consistently select the byzantine workers while discarding legitimate ones. We demonstrate our attack method works not only for preventing convergence but also for repurposing of the model behavior (``backdooring''). We show that less than 25\% of colluding workers are sufficient to degrade the accuracy of models trained on MNIST, CIFAR10 and CIFAR100 by 50\%, as well as to introduce backdoors without hurting the accuracy for MNIST and CIFAR10 datasets, but with a degradation for CIFAR100.

Cost of reproduction in the wild: manipulation of reproductive effort in the bank vole

Abstract: For three years, we manipulated litter size by adding or subtracting pups in eight wild populations of the bank vole, Clethrionomys glareolus, to examine reproductive costs and allocation of reproductive effort between offspring number and size. In general, litter enlargements did not increase the number of weanlings per mother and significantly decreased the size of weanlings. Reproductive effort and the breeding success of individuals varied within breeding seasons, but time of breeding and litter manipulation did not interact to affect reproductive trade-offs. Our 3-yr field experiment revealed that litter enlargements also reduced survival and fecundity of mothers. Small mammals have been considered typical income breeders, in which potential reproductive costs may be masked due to their ability to compensate for increased energetic demands of reproduction. Our results provide evidence that, in the wild, females may be incapable of escaping the costs of reproduction.

Large underground, liquid based detectors for astro-particle physics in Europe: scientific case and prospects

Abstract: This document reports on a series of experimental and theoretical studies conducted to assess the astro-particle physics potential of three future large scale particle detectors proposed in Europe as next generation underground observatories. The proposed apparatuses employ three different and, to some extent, complementary detection techniques: GLACIER (liquid argon TPC), LENA (liquid scintillator) and MEMPHYS (water Cherenkov), based on the use of large mass of liquids as active detection media. The results of these studies are presented along with a critical discussion of the performance attainable by the three proposed approaches coupled to existing or planned underground laboratories, in relation to open and outstanding physics issues such as the search for matter instability, the detection of astrophysical neutrinos and geo-neutrinos and to the possible use of these detectors in future high intensity neutrino beams.

Secular trends in moderate-to-vigorous physical activity in 32 countries from 2002 to 2010: a cross-national perspective

Abstract: Background: Sufficient levels of moderate to vigorous physical activity (MVPA) give substantial health benefits to adolescents. This article examines trends in physical activity (PA) from 2002 to 2010 across 32 countries from Europe and North America. Methods: Representative samples included 479 674 pupils (49% boys) aged 11 years ( n = 156 383), 13 years ( n = 163 729) and 15 years ( n = 159 562). The trends in meeting the recommendations for PA (at least 60 min daily) were evaluated using logistic regression. Results: There was a slight overall increase between 2002 and 2010 (17.0% and 18.6%, respectively). MVPA increased significantly ( P ≤ 0.05) among boys in 16 countries. Conversely, nine countries showed a significant decrease. Among girls, 10 countries showed a significant increase ( P ≤ 0.05). Eight countries showed a significant decrease. For all countries combined, girls were slightly less likely to show an increase in PA over time. Conclusions: The majority of adolescents do not meet current recommendations of PA. Further investment at national and international levels is therefore necessary to increase PA participation among children and adolescents and reduce the future health burden associated with inactivity.