4,393 research outputs found
Millimagnitude Photometry for Transiting Extrasolar Planetary Candidates III: Accurate Radius and Period for OGLE-TR-111-b
We present accurate V-band photometry for a planetary transit of OGLE-TR-111
acquired with VIMOS at the ESO Very Large Telescope. The measurement of this
transit allows to refine the planetary radius, obtaining R_p= 1.01 +/- 0.06
R_J. Given the mass of M_p = 0.53 M_J previously measured from radial
velocities, we confirm that the density is rho_p= 0.6 +/- 0.2 g/cm^3. We also
revise the ephemeris for OGLE-TR-111-b, obtaining an accurate orbital period P=
4.014484 +/- 0.000014 days, and predicting that the next observable transits
would occur around December 2006, and after that only in mid-2008. Even though
this period is different from previously published values, we cannot yet rule
out a constant period.Comment: 16 pages (including figures), 5 figures, 1 table. Accepted for
publication in the Astrophysical Journa
Acute-Stress Biomarkers in Three Octopodidae Species After Bottom Trawling
Several Octopodidae species have a great potential for the diversification of worldwide aquaculture. Unfortunately, the lack of stress-related biomarkers in this taxon results an obstacle for its maintenance in conditions where animal welfare is of paramount relevance. In this study, we made a first approach to uncover physiological responses related to fishing capture in Eledone moschata, Eledone cirrhosa, and Octopus vulgaris. Captured octopus from all three species were individually maintained in an aquaculture system onboard of oceanographic vessel in south-western waters of Europe. Haemolymph plasma and muscle were collected in animals at the moment of capture, and recovery was evaluated along a time-course of 48 h in Eledone spp., and 24 h for O. vulgaris. Survival rates of these species captured in spring and autumn were evaluated. Physiological parameters such as plasma pH, total CO2, peroxidase activity, lysozyme, hemocyanin, proteases, pro-phenoloxidase, anti-proteases, free amino acids, lactate and glucose levels, as well as muscle water percentage, free amino acids, lactate, glycogen and glucose values were analyzed. The immune system appears to be compromised in these species due to capture processes, while energy metabolites were mobilized to face the acute-stress situation, but recovery of all described parameters occurs within the first 24 h after capture. Moreover, this situation exerts hydric balance changes, as observed in the muscle water, being these responses depending on the species assessed. In conclusion, three Octopodidae species from south-western waters of Europe have been evaluated for stress-related biomarkers resulting in differentiated mechanisms between species. This study may pave the way to further study the physiology of stress in adult octopuses and develop new methodologies for their growth in aquaculture conditions
Protein tyrosine phosphatase-1B modulates pancreatic β-cell mass
Protein tyrosine phosphatase 1B (PTP1B) is a negative regulator of the insulin signalling pathway. It has been demonstrated that PTP1B deletion protects against the development of obesity and Type 2 Diabetes, mainly through its action on peripheral tissues. However, little attention has been paid to the role of PTP1B in β-cells. Therefore, our aim was to study the role of PTP1B in pancreatic β-cells. Silencing of PTP1B expression in a pancreatic β-cell line (MIN6 cells) reveals the significance of this endoplasmic reticulum bound phosphatase in the regulation of cell proliferation and apoptosis. Furthermore, the ablation of PTP1B is able to regulate key proteins involved in the proliferation and/or apoptosis pathways, such as STAT3, AKT, ERK1/2 and p53 in isolated islets from PTP1B knockout (PTP1B (-)/(-)) mice. Morphometric analysis of pancreatic islets from PTP1B (-)/(-) mice showed a higher β-cell area, concomitantly with higher β-cell proliferation and a lower β-cell apoptosis when compared to islets from their respective wild type (WT) littermates. At a functional level, isolated islets from 8 weeks old PTP1B (-)/(-) mice exhibit enhanced glucose-stimulated insulin secretion. Moreover, PTP1B (-)/(-) mice were able to partially reverse streptozotocin-induced β-cell loss. Together, our data highlight for the first time the involvement of PTP1B in β-cell physiology, reinforcing the potential of this phosphatase as a therapeutical target for the treatment of β-cell failure, a central aspect in the pathogenesis of Type 2 Diabete
Millimagnitude Optical Photometry for the Transiting Planetary Candidate OGLE-TR-109
We present precise V-band photometry for the low-amplitude transit candidate
star OGLE-TR-109. This is an extreme case among the transiting candidates found
by the OGLE group because of the early spectral type of the star (F0V), of the
low transit amplitude (A_I=0.008 mag), and of the very short period (P=0.58909
days) of the orbiting companion. Using difference image photometry, we are able
to achieve millimagnitude errors in the individual data points. One transit of
this star is well defined in our light curve. This confirms the OGLE detection
and rules out the possibility of a false positive. The measurement of this
transit allows to refine the transit amplitude (A_V=0.006 +/- 0.001 mag), and
the ephemerides for this interesting system, as well as the radius of the
possible orbiting companion (R_P=0.90 +/- 0.09 ~R_J), and the inclination of
the orbit (i=77 +/- 5 deg). Two other transits observed at lower S/N confirm
the period of this system measured by OGLE. There is no evidence for a blend of
the F-type main sequence star with a redder eclipsing binary, or for secondary
transits in the present observations. The absence of ellipsoidal modulation in
the light curve of the primary rules out a low mass star companion or brown
dwarf with M>14 +/- 8 M_J. The remaining possibilities for OGLE-TR-109 are a
blend between the F-type star and a binary with a bluer primary star, or a new
transiting extrasolar planet.Comment: 24 pages (including figures) submitteed to ApJ, Accepted. 1
replacement (updated references
Time expansion in distributed optical fiber sensing
The work of MRFR and HFM was supported by the MCIN/AEI/10.13039/501100011033 and European Union NextGenerationEU»/PRTR under grants RYC2021-032167-I and RYC2021- 035009-I.
The work of MSA and VD was supported by MCIN/AEI/10.13039/ 501100011033 and the FSE invierte en tu futuro under grants PRE-2019- 087444 and RYC-2017-23668, respectively.Distributed optical fiber sensing (DOFS) technology has recently experienced an impressive growth in various fields including security, structural monitoring and seismology, among others. This expansion has been accompanied by a speedy development of the technology in the last couple of decades, reaching remarkable performance in terms of sensitivity, range, number of independent sensing points and affordable cost per monitored point as compared with competing technologies such as electrical or point optical sensors. Phase-sensitive Optical Time-Domain Reflectometry (Ď•OTDR) is a particularly interesting DOFS technique, since it enables real-time monitoring of dynamic variations of physical parameters over a large number of sensing points. Compared to their frequency-domain counterparts (OFDR), Ď•OTDR sensors typically provide higher dynamics and longer ranges but significantly worse spatial resolutions. Very recently, a novel Ď•OTDR approach has been introduced, which covers an existing gap between the long range and fast response of Ď•OTDR and the high spatial resolution of OFDR. This technique, termed time-expanded (TE) Ď•OTDR, exploits an interferometric scheme that employs two mutually coherent optical frequency combs. In TE-Ď•OTDR, a probe comb is launched into the fiber under test. The beating of the backscattered light and a suitable LO comb produces a multi-heterodyne detection process that compresses the spectrum of the probe comb, in turn expanding the detected optical traces in the time-domain. This approach has allowed sensing using Ď•OTDR technology with very high resolution (in the cm scale), while requiring outstandingly low detection and acquisition bandwidths (sub-MHz). In this work, we review the fundamentals of TE-Ď•OTDR technology and describe the recent developments, focusing on the attainable sensing performance, the existing trade-offs and open working lines of this novel sensing approach.Comunidad de MadridMinisterio de Ciencia e InnovaciĂłnAgencia Estatal de InvestigaciĂłnGeneralitat ValencianaUniversitat Jaume IEuropean Commissio
Ancestral Resurrection and Directed Evolution of Fungal Mesozoic Laccases
ABSTRACT Ancestral sequence reconstruction and resurrection provides useful information
for protein engineering, yet its alliance with directed evolution has been
little explored. In this study, we have resurrected several ancestral nodes of fungal
laccases dating back 500 to 250 million years. Unlike modern laccases, the resurrected
Mesozoic laccases were readily secreted by yeast, with similar kinetic parameters,
a broader stability, and distinct pH activity profiles. The resurrected Agaricomycetes
laccase carried 136 ancestral mutations, a molecular testimony to its origin,
and it was subjected to directed evolution in order to improve the rate of 1,3-
cyclopentanedione oxidation, a –diketone initiator commonly used in vinyl polymerization
reactions.
IMPORTANCE The broad variety of biotechnological uses of fungal laccases is beyond
doubt (food, textiles, pulp and paper, pharma, biofuels, cosmetics, and bioremediation),
and protein engineering (in particular, directed evolution) has become
the key driver for adaptation of these enzymes to harsh industrial conditions. Usually,
the first requirement for directed laccase evolution is heterologous expression,
which presents an important hurdle and often a time-consuming process. In this
work, we resurrected a fungal Mesozoic laccase node which showed strikingly high
heterologous expression and pH stability. As a proof of concept that the ancestral
laccase is a suitable blueprint for engineering, we performed a quick directed evolution
campaign geared to the oxidation of the -diketone 1,3-cyclopentanedione, a
poor laccase substrate that is used in the polymerization of vinyl monomers
Supplementation of vitamin E and C prevent granulomatosis in meagre larvae
Systemic granulomatosis has already been reported in meagre larvae with an adequate feeding protocol and enrichment media preventing its appearance in the first weeks of life. Afterwards, the control of this disease could be prevented through nutritional components of the inert food, being the antioxidants the key to success. For this reason, in the present study, meagre larvae were reared from 30 days post hatching (dph) with five isonitrogenous and isolipidic experimental microdiets with different levels of vitamin E and C: C- (40 mg kg-1 E, 100 mg kg-1 C), C+ (400 mg kg-1 E, 1,000 mg kg-1 C), Krill (400 mg kg-1 E, 1,000 mg kg-1 C and substitution of fish oil by krill oil), EC (200 mg kg-1 E, 500 mg kg-1 C) and EECC (800 mg kg-1 E, 2,000 mg kg-1 C). Prior to this, larvae were co-fed with rotifers and Artemia following a protocol which prevented the appearance of granulomas, as previously demonstrated. The substitution of fish oil by krill oil significantly increased levels of eicosapentaenoic acid (EPA, 16.6 %) and docosahexaenoic acid (DHA, 17.6 %) in meagre, consequently increasing the peroxidation index, which in turn translated into a higher incidence of granulomas. Although even low levels of vitamin E and C (40 mg kg-1 E, 100 mg kg-1 C; C-) allowed the adequate growth of larvae, these levels were not enough to prevent the appearance of granulomas, requiring superior levels of both antioxidant vitamins (800 mg kg-1 E and 2,000 mg kg-1 C) to mitigate systemic granulomatosis. This mitigation was simultaneous with the reduction of thiobarbituric acid reactive substances TBARs content in larvae, which were highly correlated with the appearance of granulomas (R2=0.892, y=0.0446x+0.0756). A strong negative correlation was observed between the dietary levels of vitamin E (y = -0.0098x + 11.174, R2 = 0.8766, p value = 0.019, r = -0.93) and vitamin C (y = -0.0022x + 6.4777, R2 = 0.9278, p value = 0.003, r = -0.96) and the percentage of larvae with granulomas. The results showed that the occurrence of systemic granulomatosis seems to be associated to the larvae peroxidation status, so that high dietary levels of vitamin E and C (800 and 2,000 mg kg-1, respectively; Diet EECC), reduced lipid peroxidation and completely prevented the appearance of granulomas in meagre larvae at 44 dph
Three-dimensional assessment of the judo throwing techniques frequently used in competition
Background and Study Aim: Although the judo throwing techniques are not considered as injurious to the attacker, repetition of these techniques might cause repetitive strain type injuries. The goal of the study was knowledge about the degrees of flexion and extension and abduction and adduction of the main locomotive joints, performing the most employed throwing techniques in high-level competition.
Material and Methods: Two world-class judoists, under the supervision of an elite Japanese expert, performed seoi-nage, uchi-mata, osoto-gari, ouchi-gari and kouchi-gari. They were analysed using three-dimensional technology.
Results: Data of performance throws obtained from expert 1 and 2 respectively were very similar. Results indicate that systematic repetition of seoi-nage, uchi-mata and o-soto-gari can produce shoulder tendon pathologies. Long-term seoi-nage and uchi-mata practice might generate epicondylitis. Judokas who have suffered anterior cruciate ligament injuries must be careful when executing techniques that demand explosive knee extension (i.e. seoi-nage) against a great resistance. Judokas are not exposed to overuse injuries when they perform ouchi-gari and kouchi-gari throws.
Conclusions: Systematic practice of the most employed judo throwing techniques in high-level judo can cause injuries by overuse in the upper-body joints (shoulder, elbow). Nevertheless, the lower-body joints (knee, ankle) do not seem to be at risk of injury by overuse
Does Socioeconomic Status Influence the Risk of Subclinical Atherosclerosis?: A Mediation Model
BACKGROUND: Socioeconomic status (SES)-education, income level, and occupation-is associated with cardiovascular risk. OBJECTIVES: This study aimed to investigate the association between SES and subclinical atherosclerosis and the potential mechanisms involved. METHODS: SES, lifestyle habits (smoking, dietary patterns, physical activity, and hours of sleep), traditional risk factors, and subclinical atherosclerosis extent were prospectively assessed in 4,025 individuals aged 40 to 54 years without known cardiovascular disease enrolled in the PESA (Progression of Early Subclinical Atherosclerosis) study. After factors associated with atherosclerosis were identified, a multiple mediation model was created to quantify the effect of SES on subclinical atherosclerosis as explained by lifestyle behaviors. RESULTS: Although education level was significantly associated with the presence of atherosclerosis, no differences were found according to income level in this population. Participants with lower education presented with a higher risk of generalized atherosclerosis than those with higher education (odds ratio: 1.46; 95% confidence interval: 1.15 to 1.85; p = 0.002). Lifestyle behaviors associated with both education level and atherosclerosis extent were: smoking status, number of cigarettes/day, and dietary pattern, which explained 70.5% of the effect of SES on atherosclerosis. Of these, tobacco habit (smoking status 35% and number of cigarettes/day 32%) accounted for most of the explained differences between groups, whereas dietary pattern did not remain a significant mediator in the multiple mediation model. CONCLUSIONS: Despite the relative economic homogeneity of the cohort, lower education level is associated with increased subclinical atherosclerosis, mainly mediated by the higher and more frequent tobacco consumption. Smoking cessation programs are still needed, particularly in populations with lower education level.The PESA study is cofunded equally by the Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain; and Banco Santander, Madrid, Spain. The study also receives funding from the Institute of Health Carlos III (PI15/02019) and the European Regional Development Fund. The CNIC is supported by the Ministry of Economy, Industry and Competitiveness and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505). This work is part of a project that has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No707642; and from the American Heart Association under grantnumber14SFRN20490315. Dr. Bueno has received research funding from the Instituto de Salud Carlos III (PIE16/00021), AstraZeneca, Bristol-Myers Squibb, Janssen, and Novartis; has received consulting fees from Abbott, AstraZeneca, Bayer, Bristol-Myers Squibb-Pfizer, and Novartis; and has received speaking fees or support for attending scientific meetings from AstraZeneca, Bayer, Bristol-Myers Squibb-Pfizer, Ferrer, Novartis, Servier, and MEDSCAPE-the heart.org.S
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