7,974 research outputs found
Striking circadian neuron diversity and cycling of Drosophila alternative splicing.
Although alternative pre-mRNA splicing (AS) significantly diversifies the neuronal proteome, the extent of AS is still unknown due in part to the large number of diverse cell types in the brain. To address this complexity issue, we used an annotation-free computational method to analyze and compare the AS profiles between small specific groups of Drosophila circadian neurons. The method, the Junction Usage Model (JUM), allows the comprehensive profiling of both known and novel AS events from specific RNA-seq libraries. The results show that many diverse and novel pre-mRNA isoforms are preferentially expressed in one class of clock neuron and also absent from the more standard Drosophila head RNA preparation. These AS events are enriched in potassium channels important for neuronal firing, and there are also cycling isoforms with no detectable underlying transcriptional oscillations. The results suggest massive AS regulation in the brain that is also likely important for circadian regulation
Work and information processing in a solvable model of Maxwell's demon
We describe a minimal model of an autonomous Maxwell demon, a device that
delivers work by rectifying thermal fluctuations while simultaneously writing
information to a memory register. We solve exactly for the steady-state
behavior of our model, and we construct its phase diagram. We find that our
device can also act as a "Landauer eraser", using externally supplied work to
remove information from the memory register. By exposing an explicit,
transparent mechanism of operation, our model offers a simple paradigm for
investigating the thermodynamics of information processing by small systems.Comment: Main Text (6 pages, 3 figures) + Suppl. Info. (3 pages). To appear in
PNA
Sub-Doppler laser cooling of fermionic 40K atoms in three-dimensional gray optical molasses
We demonstrate sub-Doppler cooling of 40K on the D_1 atomic transition. Using
a gray molasses scheme, we efficiently cool a compressed cloud of 6.5x10^8
atoms from ~ 4\mK to 20uK in 8 ms. After transfer in a quadrupole magnetic
trap, we measure a phase space density of ~10^-5. This technique offers a
promising route for fast evaporation of fermionic 40K.Comment: 6 pages; 7 figures; submitted to EP
Nootropics use in the workplace. Psychiatric and ethical aftermath towards the new frontier of bioengineering
OBJECTIVE:
The authors have sought to expound upon and shed a light on the rise of nootropics, which have gradually taken on a more and more relevant role in workplaces and academic settings.
MATERIALS AND METHODS:
Multidisciplinary databases have been delved into by entering the following keys: "nootropics", "cognitive enhancement", "workplace", "productivity", "ethics", "bioengineering". In addition, a broad-ranging search has been undertaken on institutional websites in order to identify relevant analysis and recommendations issued by international institutions and agencies. Papers and reports have been independently pored over by each author. This search strategy has led to the identification of 988 sources but only 64 were considered appropriate for the purposes of the paper after being selected by at least 3 of the authors, independently.
RESULTS:
The notion of an artificially enhanced work performance - carried out by the 'superworker' - is particularly noteworthy and resonates with the conception of contemporary work on so many different levels: the rising need and demands for higher degrees of flexibility and productivity on the job, the implications of a '24/7' society, where more and more services are available at any time, the ever greater emphasis on entrepreneurial spirit, individual self-reliance and self-improvement, and last but not least, the impact of an ageing society on economic standards and performance.
CONCLUSIONS:
Moreover, it is worth mentioning that human enhancement technologies will predictably and increasingly go hand in hand with gene editing, bioengineering, cybernetics and nanotechnology. Applications are virtually boundless, and may ultimately affect all human traits (physical strength, endurance, vision, intelligence and even personality and mood)
Irish Studies in Spain: 2015-March 2016
In October 2015 the Irish fashion retailer chain Primark opened its second world-wide biggest premises in Madrid. Low-cost fashion, low-cost travel, low-cost food … low-cost life? What about quality? Fortunately, Irish-Spanish relationships cannot be reduced to economic endeavours or to the Kinahan mafia clan criminal forays into the Spanish “Costa del Sol” (Málaga).
Even if the period covered by this review has not been particularly fruitful in terms of publications by Spanish or Spanish affiliated scholars, it has been rich in cultural events, both academic and informative, with assorted commemorations and celebrations of Irish culture, particularly music, cinema and literature. I will start here by first commenting on Spanish translations of both fictional and non-fictional works by Irish authors
IN-SYNC. VII. Evidence for a decreasing spectroscopic binary fraction from 1 to 100 Myr within the IN-SYNC sample
We study the occurrence of spectroscopic binaries in young star-forming
regions using the INfrared Spectroscopy of Young Nebulous Clusters(IN-SYNC)
survey, carried out in SDSS-III with the APOGEE spectrograph. Multi-epoch
observations of thousands of low-mass stars in Orion A, NGC 2264, NGC 1333, IC
348, and the Pleiades have been carried out, yielding H-band spectra with a
nominal resolution of R=22,500 for sources with H 12 mag. Radial velocity
precisions of 0.3 were achieved, which we use to identify
radial velocity variations indicative of undetected companions. We use Monte
Carlo simulations to assess the types of spectroscopic binaries to which we are
sensitive, finding sensitivity to binaries with orbital periods d,
for stars with and 100 . Using Bayesian inference, we find evidence
for a decline in the spectroscopic binary fraction, by a factor of 3-4 from the
age of our pre-main-sequence sample to the Pleiades age . The significance of
this decline is weakened if spot-induced radial-velocity jitter is strong in
the sample, and is only marginally significant when comparing any one of the
pre-main-sequence clusters against the Pleiades. However, the same decline in
both sense and magnitude is found for each of the five pre-main-sequence
clusters, and the decline reaches statistical significance of greater than 95%
confidence when considering the pre-main-sequence clusters jointly. Our results
suggest that dynamical processes disrupt the widest spectroscopic binaries
( d) as clusters age, indicating that this
occurs early in the stars' evolution, while they still reside within their
nascent clusters.Comment: 21 pages, 9 Figure
IN-SYNC. VIII. Primordial Disk Frequencies in NGC 1333, IC 348, and the Orion A Molecular Cloud
In this paper, we address two issues related to primordial disk evolution in
three clusters (NGC 1333, IC 348, and Orion A) observed by the INfrared Spectra
of Young Nebulous Clusters (IN-SYNC) project. First, in each cluster, averaged
over the spread of age, we investigate how disk lifetime is dependent on
stellar mass. The general relation in IC 348 and Orion A is that primordial
disks around intermediate mass stars (2--5) evolve faster than those
around loss mass stars (0.1--1), which is consistent with previous
results. However, considering only low mass stars, we do not find a significant
dependence of disk frequency on stellar mass. These results can help to better
constrain theories on gas giant planet formation timescales. Secondly, in the
Orion A molecular cloud, in the mass range of 0.35--0.7, we provide
the most robust evidence to date for disk evolution within a single cluster
exhibiting modest age spread. By using surface gravity as an age indicator and
employing 4.5 excess as a primordial disk diagnostic, we observe a
trend of decreasing disk frequency for older stars. The detection of
intra-cluster disk evolution in NGC 1333 and IC 348 is tentative, since the
slight decrease of disk frequency for older stars is a less than 1-
effect.Comment: 25 pages, 26 figures; submitted for publication (ApJ
- …