5,559 research outputs found
The blood biomarkers puzzle â A review of protein biomarkers in neurodegenerative diseases
Neurodegenerative diseases are heterogeneous in their cause and clinical presentation making clinical assessment and disease monitoring challenging. Because of this, there is an urgent need for objective tools such as fluid biomarkers able to quantitate different aspects of the disease. In the last decade, technological improvements and awareness of the importance of biorepositories led to the discovery of an evolving number of fluid biomarkers covering the main characteristics of neurodegenerative diseases such as neurodegeneration, protein aggregates and inflammation. The ability to quantitate each aspect of the disease at a high definition enables a more precise stratification of the patients at inclusion in clinical trials, hence reducing the noise that may hamper the detection of therapeutical efficacy and allowing for smaller but likewise powered studies, which particularly improves the ability to start clinical trials for rare neurological diseases. Moreover, the use of fluid biomarkers has the potential to support a targeted therapeutical intervention, as it is now emerging for the treatment of amyloid-beta deposition in patients suffering from Alzheimer's disease. Here we review the knowledge that evolved from the measurement of fluid biomarker proteins in neurodegenerative conditions
Neurological symptoms and blood neurofilament light levels
Neurofilament light chain (NfL) is an incredibly specific marker of neuronal injury that is not specific for cause or location of the neuronal damage. NfL is increasingly considered as possible biomarker of disease activity in neurological conditions. Several works reviewed the utility of NfL in the different diseases. Nonetheless, NfL is a universal marker of neuronal damage, which interpretation spaces beyond the single disease. Because of this, the interpretation of NfL may benefit by also considering how neurological symptoms relate to its blood concentration. Here, we review how different neurological symptoms can be associated with blood NfL levels with a practical interpretation of it
Exploring the evolutionary paths of the most massive galaxies since z~2
We use Spitzer MIPS data from the FIDEL Legacy Project in the Extended Groth
Strip to analyze the stellar mass assembly of massive (M>10^11 M_sun) galaxies
at z<2 as a function of structural parameters. We find 24 micron emission for
more than 85% of the massive galaxies morphologically classified as disks, and
for more than 57% of the massive systems morphologically classified as
spheroids at any redshift, with about 8% of sources harboring a bright X-ray
and/or infrared emitting AGN. More noticeably, 60% of all compact massive
galaxies at z=1-2 are detected at 24 micron, even when rest-frame optical
colors reveal that they are dead and evolving passively. For spheroid-like
galaxies at a given stellar mass, the sizes of MIPS non-detections are smaller
by a factor of 1.2 in comparison with IR-bright sources. We find that disk-like
massive galaxies present specific SFRs ranging from 0.04 to 0.2 Gyr^-1 at z<1
(SFRs ranging from 1 to 10 M_sun/yr), typically a factor of 3-6 higher than
massive spheroid-like objects in the same redshift range. At z>1, and more
pronouncedly at z>1.3, the median specific SFRs of the disks and spheroids
detected by MIPS are very similar, ranging from 0.1 to 1 Gyr^-1 (SFR=10-200
M_sun/yr). We estimate that massive spheroid-like galaxies may have doubled (at
the most) their stellar mass from star-forming events at z<2: less than 20%
mass increase at 1.7<z<2.0, up to 40% more at 1.1<z<1.7, and less than 20%
additional increase at z<1. Disk-like galaxies may have tripled (at the most)
their stellar mass at z<2 from star formation alone: up to 40% mass increase at
1.7<z<2.0, and less than 180% additional increase below z=1.7 occurred at a
steady rate.Comment: Accepted for publication in ApJ; 10 pages, 5 figures, 1 tabl
Evolution of the anti-truncated stellar profiles of S0 galaxies since in the SHARDS survey: I - Sample and Methods
The controversy about the origin of the structure of S0--E/S0 galaxies may be
due to the difficulty of comparing surface brightness profiles with different
depths, photometric corrections and PSF effects (almost always ignored). We aim
to quantify the properties of Type-III (anti-truncated) discs in a sample of S0
galaxies at 0.2<z<0.6. In this paper, we present the sample selection and
describe in detail the methods to robustly trace the structure in their
outskirts and correct for PSF effects. We have selected and classified a sample
of 150 quiescent galaxies at 0.2<z<0.6 in the GOODS-N field. We perform a
quantitative structural analysis of 44 S0-E/S0 galaxies. We corrected their
surface brightness profiles for PSF distortions and analysed the biases in the
structural and photometric parameters when the PSF correction is not applied.
Additionally, we have developed Elbow, an automatic statistical method to
determine whether a possible break is significant - or not - and its type and
made it publicly available. We found 14 anti-truncated S0-E/S0 galaxies in the
range 0.2<z<0.6 (~30% of the final sample). This fraction is similar to the
those reported in the local Universe. In our sample, ~25% of the Type-III
breaks observed in PSF-uncorrected profiles are artifacts, and their profiles
turn into a Type I after PSF correction. PSF effects also soften Type-II
profiles. We found that the profiles of Type-I S0 and E/S0 galaxies of our
sample are compatible with the inner profiles of the Type-III, in contrast with
the outer profiles. We have obtained the first robust and reliable sample of 14
anti-truncated S0--E/S0 galaxies beyond the local Universe, in the range
0.2<z<0.6. PSF effects significantly affect the shape of the surface brightness
profiles in galaxy discs even in the case of the narrow PSF of HST/ACS images,
so future studies on the subject should make an effort to correct them.Comment: Accepted for publishing in Astronomy & Astrophysics. 75 pages, 57
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An assessment of the benefits of yellow Sigatoka (Mycosphaerella musicola) control in the Queensland Northern Banana Pest Quarantine Area
The banana leaf spotting disease yellow Sigatoka is established and actively controlled in Australia through intensive chemical treatments and diseased leaf removal. In the State of Queensland, the State government imposes standards for de-leafing to minimise the risk of the disease spreading in 6 banana pest quarantine areas. Of these, the Northern Banana Pest Quarantine Area is the most significant in terms of banana production. Previous regulations imposed obligations on owners of banana plants within this area to remove leaves from plants with visible spotting on more than 15 per cent of any leaf during the wet season. Recently, this leaf disease threshold has been lowered to 5 per cent. In this paper we examine the likely impact this more-costly regulation will have on the spread of the disease. We estimate that the average net benefit of reducing the diseased leaf threshold is only likely to be $1.4 million per year over the next 30 years, expressed as the annualised present value of tightened regulation. This result varies substantially when the timeframe of the analysis is changed, with shorter time frames indicating poorer net returns from the change in protocols. Overall, the benefit of the regulation change is likely to be minor
Effect of zaĂŻ and micro dose on root biomass and the grain and straw yield so sorghum at Tangaye in the North region in Burkina Faso
Faced with rainfall variation and the poor performance of farming practices, the North region of Burkina Faso often observed cereal deficits. Sorghum, the main staple food crop in this region, provides relatively low yields (1000 kgha-1). Furthermore, in the area, the density of the population is one of the highest in the country. In order to increase sorghum yields, a study has been carried out in the village of Tangaye by combining the water management practice through mechanized and manual zaĂŻ techniques with fertilization by microdose of NPK fertilizer. The experimental design of the study was a split-plot with three replications and four treatments set on a crusty bear soil âZipellĂ©â.The mechanized zaĂŻ and the manual zaĂŻ have been compared with and without applying mineral NPK fertilizer by a micro dose. The effects of these techniques have been evaluated on the soil and the root system by the method of taking monoliths. The grain and straw yields of sorghum have been evaluated for each treatment. The results showed that the greatest roots system development was obtained on the mechanized zaĂŻ plot with the application of micro dose of NPK fertilizer. This treatment also has the highest grain yield (2910 kgha-1) compared to manual ZaĂŻ (1620 kgha-1
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