31 research outputs found
Mediterranean diet, physical activity and gut microbiome composition: A cross-sectional study among healthy young italian adults
Background. This cross-sectional study aimed to explore the microbial composition of the gut and its possible association with the Mediterranean diet (MD) after adjusting for demographic and anthropometric characteristics in a sample of healthy young Italian adults. Methods. Gut microbiota, demographic information, and data on adherence to MD and physical activity (PA) habits were collected in a sample of 140 university students (48.6% males, mean age 22.5 ± 2.9) with a mean body mass index (BMI) of 22.4 ± 2.8 kg/m2 (15.2â33.8) and a mean PA level of 3006.2 ± 2973.6 metabolic equivalent (MET)-minutes/week (148â21,090). Results. A high prevalence of Firmicutes and Bacteroidetes was found in all the fecal samples. Significant dissimilarities in the microbiota composition were found on the basis of MD adherence and PA levels (p = 0.001). At the genus level, Streptococcus and Dorea were highly abundant in overweight/obese individuals, Ruminococcus and Oscillospira in participants with lower adherence to MD, and Lachnobacterium in subjects with low levels of PA (p = 0.001). A significantly higher abundance of Paraprevotella was shown by individuals with lower BMI, lower MD adherence, and lower PA levels (p = 0.001). Conclusions. This study contributes to the characterization of the gut microbiome of healthy humans. The findings suggest the role of diet and PA in determining gut microbiota variability
Transition probabilities for general birth-death processes with applications in ecology, genetics, and evolution
A birth-death process is a continuous-time Markov chain that counts the
number of particles in a system over time. In the general process with
current particles, a new particle is born with instantaneous rate
and a particle dies with instantaneous rate . Currently no robust and
efficient method exists to evaluate the finite-time transition probabilities in
a general birth-death process with arbitrary birth and death rates. In this
paper, we first revisit the theory of continued fractions to obtain expressions
for the Laplace transforms of these transition probabilities and make explicit
an important derivation connecting transition probabilities and continued
fractions. We then develop an efficient algorithm for computing these
probabilities that analyzes the error associated with approximations in the
method. We demonstrate that this error-controlled method agrees with known
solutions and outperforms previous approaches to computing these probabilities.
Finally, we apply our novel method to several important problems in ecology,
evolution, and genetics
A complementary study approach unravels novel players in the pathoetiology of Hirschsprung disease
Hirschsprung disease (HSCR, OMIM 142623) involves congenital intestinal obstruction
caused by dysfunction of neural crest cells and their progeny during enteric nervous system
(ENS) development. HSCR is a multifactorial disorder; pathogenetic variants accounting for
disease phenotype are identified only in a minority of cases, and the identification of novel
disease-relevant genes remains challenging. In order to identify and to validate a potential
disease-causing relevance of novel HSCR candidate genes, we established a complementary study approach, combining whole exome sequencing (WES) with transcriptome analysis of murine embryonic ENS-related tissues, literature and databas
Snow Moving to Higher Elevations : Analyzing Three Decades of Snowline Dynamics in the Alps
In the Alps, snow cover dynamics can be monitored using Earth observation (EO). However,
low revisit frequency and cloud cover pose a challenge to longâterm time series analysis using high spatial
resolution EO images. In this study, we applied the random forest regression to model regional snowline
elevations (RSEs). In this manner, daily snowline dynamics and their longâterm trends can be derived,
despite the aforementioned challenges. Of the six investigated Alpine catchments between 1984 and 2018, a
significant increasing trend of RSEs is shown in four catchments in the early ablation seasons (between
5.38 ± 2.64 and 11.29 ± 4.79 m·aâ1) and five catchments in the middle ablation seasons (between 4.17 ± 2.62
and 8.76 ± 4.42 m·aâ1). On average, the random forest regression models can explain 75% of the RSE
variations. Furthermore, air temperature was found influential in snow persistence especially during middle
and late ablation seasons
Review of the technology and reliability issues arising as optical interconnects migrate onto the circuit board
Light has the greatest information carrying potential of all the perceivable interconnect mediums; consequently, optical fiber interconnects rapidly replaced copper in telecommunications networks, providing bandwidth capacity far in excess of its predecessors. As a result the modern telecommunications infrastructure has evolved into a global mesh of optical networks with VCSELâs (Vertical Cavity Surface Emitting Lasers) dominating the short-link markets, predominately due to their low-cost. This cost benefit of VCSELs has allowed optical interconnects to again replace bandwidth limited copper as bottlenecks appear on VSR (Very Short Reach) interconnects between co-located equipment inside the CO (Central-Office).
Spurred by the successful deployment in the VSR domain and in response to both intra-board backplane applications and inter-board requirements to extend the bandwidth between ICâs (Integrated Circuits), current research is migrating optical links toward board level USR (Ultra Short Reach) interconnects. Whilst reconfigurable Free Space Optical Interconnect (FSOI) are an option, they are complicated by precise line-of-sight alignment conditions hence benefits exist in developing guided wave technologies, which have been classified into three generations. First and second generation technologies are based upon optical fibers and are both capable of providing a suitable platform for intra-board applications. However, to allow component assembly, an integral requirement for inter-board applications, 3rd generation Opto-Electrical Circuit Boards (OECBâs) containing embedded waveguides are desirable.
Currently, the greatest challenge preventing the deployment of OECBâs is achieving the out-of-plane coupling to SMT devices. With the most suitable low-cost platform being to integrate the optics into the OECB manufacturing process, several research avenues are being explored although none to date have demonstrated sufficient coupling performance. Once in place, the OECB assemblies will generate new reliability issues such as assembly configurations, manufacturing tolerances, and hermetic requirements that will also require development before total off-chip photonic interconnection can truly be achieve