1,145 research outputs found
Polarized sea measurements at JPARC
Large double spin-asymmetries can be foreseen for Drell-Yan production in scattering at JPARC energies. The sign of the asymmetries can be used to
discriminate between different model calculations of sea quark distributions.Comment: 4 pages, 2 figures, Proceedings of DIS2006, Kyoto 200
Effect of Lactobacillus rhamnosus HN001 and Bifidobacterium longum BB536 on the healthy gut microbiota composition at phyla and species level: a preliminary study
AIM:
To evaluate the ability of Lactobacillus rhamnosus HN001 and Bifidobacterium longum BB536 to colonize the intestinal environment of healthy subjects and modify the gut microbiota composition.
METHODS:
Twenty healthy Italian volunteers, eight males and twelve females, participated in the study. Ten subjects took a sachet containing 4 × 109 colony-forming units (CFU) of Bifidobacterium longum BB536 and 109 CFU of Lactobacillus rhamnosus HN001, 30 min before breakfast (pre-prandial administration), while ten subjects took a sachet of probiotic product 30 min after breakfast (post-prandial administration). The ability of Lactobacillus rhamnosus HN001 and Bifidobacterium longum BB536 to colonize human gut microbiota was assessed by means of quantitative real-time PCR, while changes in gut microbiota composition were detected by using Ion Torrent Personal Genome Machine.
RESULTS:
Immediately after 1-mo of probiotic administration, B. longum BB536 and L. rhamnosus HN001 load was increased in the majority of subjects in both pre-prandial and post-prandial groups. This increase was found also 1 mo after the end of probiotic oral intake in both groups, if compared to samples collected before probiotic consumption. At phyla level a significant decrease in Firmicutes abundance was detected immediately after 1-mo of B. longum BB536 and L. rhamnosus HN001 oral intake. This reduction persisted up to 1 mo after the end of probiotic oral intake together with a significant decrease of Proteobacteria abundance if compared to samples collected before probiotic administration. Whereas, at species level, a higher abundance of Blautia producta, Blautia wexlerae and Haemophilus ducrey was observed, together with a reduction of Holdemania filiformis, Escherichia vulneris, Gemmiger formicilis and Streptococcus sinensis abundance. In addition, during follow-up period we observed a further reduction in Escherichia vulneris and Gemmiger formicilis, together with a decrease in Roseburia faecis and Ruminococcus gnavus abundance. Conversely, the abundance of Akkermansia muciniphila was increased if compared to samples collected at the beginning of the experimental time course.
CONCLUSION:
B. longum BB536 and L. rhamnosus HN001 showed the ability to modulate the gut microbiota composition, leading to a significant reduction of potentially harmful bacteria and an increase of beneficial ones. Further studies are needed to better understand the specific mechanisms involved in gut microbiota modulation
Inside Dropbox: Understanding Personal Cloud Storage Services
Personal cloud storage services are gaining popularity. With a rush of providers to enter the market and an increasing of- fer of cheap storage space, it is to be expected that cloud storage will soon generate a high amount of Internet traffic. Very little is known about the architecture and the perfor- mance of such systems, and the workload they have to face. This understanding is essential for designing efficient cloud storage systems and predicting their impact on the network. This paper presents a characterization of Dropbox, the leading solution in personal cloud storage in our datasets. By means of passive measurements, we analyze data from four vantage points in Europe, collected during 42 consecu- tive days. Our contributions are threefold: Firstly, we are the first to study Dropbox, which we show to be the most widely-used cloud storage system, already accounting for a volume equivalent to around one third of the YouTube traffic at campus networks on some days. Secondly, we characterize the workload typical users in different environments gener- ate to the system, highlighting how this reflects on network traffic. Lastly, our results show possible performance bot- tlenecks caused by both the current system architecture and the storage protocol. This is exacerbated for users connected far from control and storage data-center
Evolution of Strigamia centipedes (Chilopoda): a first molecular assessment of phylogeny and divergence times
We present a first phylogenetic and temporal framework, with biogeographical insights, for the centipedes of the genus Strigamia, which are widespread predators in the forest soils of the Northern Hemisphere and comprise the evo-devo model species Strigamia maritima. The phylogeny was estimated by different methods of maximum likelihood and Bayesian inference from sequences of two mitochondrial (16S, COI) and two nuclear (18S, 28S) genes, obtained from 16 species from all major areas of the global range of the genus and encompassing most of the overall morphological and ecological diversity. Divergence times were estimated after calibration upon the fossil record of centipedes. We found that major lineages of extant species of Strigamia separated most probably around 60 million years (Ma) ago. The two most diverse lineages diversified during the last 30 Ma and are today segregated geographically, one in Europe and another in Eastern Asia. This latter region hosts a hitherto underestimated richness and anatomical diversity of species, including three still unknown, yet morphologically well distinct species, which are here described as new: Strigamia inthanoni sp. n. from Thailand, Strigamia korsosi sp. n. from the Ryukyu Islands and Strigamia nana sp. n. from Taiwan. The northern European model species S. maritima is more strictly related to the Eastern Asian lineage, from which it most probably separated around 35 Ma ago before the major diversification of the latter
Towards Understanding Political Interactions on Instagram
Online Social Networks (OSNs) allow personalities and companies to
communicate directly with the public, bypassing filters of traditional medias.
As people rely on OSNs to stay up-to-date, the political debate has moved
online too. We witness the sudden explosion of harsh political debates and the
dissemination of rumours in OSNs. Identifying such behaviour requires a deep
understanding on how people interact via OSNs during political debates. We
present a preliminary study of interactions in a popular OSN, namely Instagram.
We take Italy as a case study in the period before the 2019 European Elections.
We observe the activity of top Italian Instagram profiles in different
categories: politics, music, sport and show. We record their posts for more
than two months, tracking "likes" and comments from users. Results suggest that
profiles of politicians attract markedly different interactions than other
categories. People tend to comment more, with longer comments, debating for
longer time, with a large number of replies, most of which are not explicitly
solicited. Moreover, comments tend to come from a small group of very active
users. Finally, we witness substantial differences when comparing profiles of
different parties.Comment: 5 pages, 8 figure
Regression of Environmental Noise in LIGO Data
We address the problem of noise regression in the output of
gravitational-wave (GW) interferometers, using data from the physical
environmental monitors (PEM). The objective of the regression analysis is to
predict environmental noise in the gravitational-wave channel from the PEM
measurements. One of the most promising regression method is based on the
construction of Wiener-Kolmogorov filters. Using this method, the seismic noise
cancellation from the LIGO GW channel has already been performed. In the
presented approach the Wiener-Kolmogorov method has been extended,
incorporating banks of Wiener filters in the time-frequency domain,
multi-channel analysis and regulation schemes, which greatly enhance the
versatility of the regression analysis. Also we presents the first results on
regression of the bi-coherent noise in the LIGO data
A Proposed Search for the Detection of Gravitational Waves from Eccentric Binary Black Holes
Most of compact binary systems are expected to circularize before the
frequency of emitted gravitational waves (GWs) enters the sensitivity band of
the ground based interferometric detectors. However, several mechanisms have
been proposed for the formation of binary systems, which retain eccentricity
throughout their lifetimes. Since no matched-filtering algorithm has been
developed to extract continuous GW signals from compact binaries on orbits with
low to moderate values of eccentricity, and available algorithms to detect
binaries on quasi-circular orbits are sub-optimal to recover these events, in
this paper we propose a search method for detection of gravitational waves
produced from the coalescences of eccentric binary black holes (eBBH). We study
the search sensitivity and the false alarm rates on a segment of data from the
second joint science run of LIGO and Virgo detectors, and discuss the
implications of the eccentric binary search for the advanced GW detectors
Leveraging waveform complexity for confident detection of gravitational waves
The recent completion of Advanced LIGO suggests that gravitational waves may soon be directly observed. Past searches for gravitational-wave transients have been impacted by transient noise artifacts, known as glitches, introduced into LIGO data due to instrumental and environmental effects. In this work, we explore how waveform complexity, instead of signal-to-noise ratio, can be used to rank event candidates and distinguish short duration astrophysical signals from glitches. We test this framework using a new hierarchical pipeline that directly compares the Bayesian evidence of explicit signal and glitch models. The hierarchical pipeline is shown to perform well and, in particular, to allow high-confidence detections of a range of waveforms at a realistic signal-to-noise ratio with a two-detector network
Parthenolide prevents resistance of MDA-MB231 cells to doxorubicin and mitoxantrone: the role of Nrf2
Triple-negative breast cancer is a group of aggressive cancers with poor prognosis owing to chemoresistance, recurrence and metastasis. New strategies are required that could reduce chemoresistance and increases the effectiveness of chemotherapy. The results presented in this paper, showing that parthenolide (PN) prevents drug resistance in MDA-MB231 cells, represent a contribution to one of these possible strategies. MDA-MB231 cells, the most studied line of TNBC cells, were submitted to selection treatment with mitoxantrone (Mitox) and doxorubicin (DOX). The presence of resistant cells was confirmed through the measurement of the resistance index. Cells submitted to this treatment exhibited a remarkable increment of NF-E2-related factor 2 (Nrf2) level, which was accompanied by upregulation of catalase, MnSOD, HSP70, Bcl-2 and P-glycoprotein. Moreover, as a consequence of overexpression of Nrf2 and correlated proteins, drug-treated cells exhibited a much lower ability than parental cells to generate ROS in response to a suitable stimulation. The addition of PN (2.0 μM) to Mitox and DOX, over the total selection time, prevented both the induction of resistance and the overexpression of Nrf2 and correlated proteins, whereas the cells showed a good ability to generate ROS in response to adequate stimulation. To demonstrate that Nrf2 exerted a crucial role in the induction of resistance, the cells were transiently transfected with a specific small interfering RNA for Nrf2. Similarly to the effects induced by PN, downregulation of Nrf2 was accompanied by reductions in the levels of catalase, MnSOD, HSP70 and Bcl-2, prevention of chemoresistance and increased ability to generate ROS under stimulation. In conclusion, our results show that PN inhibited the development of the resistance toward Mitox and DOX, and suggest that these effects were correlated with the prevention of the overexpression of Nrf2 and its target proteins, which occurred in the cells submitted to drug treatment
- …
