775 research outputs found
NONLINEAR MONETARY POLICY RULES: SOME NEW EVIDENCE FOR THE US
This paper dreives optimal monetary policy rules in setups where certainty equivalence does not hold because either central bank preferences are not quadratic, and/or the aggregate supply relation is nonlinear. Analytical results show that these features lead to sign and size aymmetries, and nonlinearities in the policy rule. Reduced-form estimates indicate that US monetary policy can be characterized by a nonlinear policy rule after 1983, but not before 1979. This finding is consistent with the view that the Fed`s inflation preferences during the Volcker-Greenspan regime differ considerably from the ones during the Burns-Miller regime.
The role of MYC and PP2A in the initiation and progression of myeloid leukemias
The MYC transcription factor is one of the best characterized PP2A substrates. Deregulation of the MYC oncogene, along with inactivation of PP2A, are two frequent events in cancer. Both proteins are essential regulators of cell proliferation, apoptosis, and differentiation, and they, directly and indirectly, regulate each other's activity. Studies in cancer suggest that targeting the MYC/PP2A network is an achievable strategy for the clinic. Here, we focus on and discuss the role of MYC and PP2A in myeloid leukemias
Nonlinear Monetary Policy Rules: Some New Evidence for the U.S.
This paper derives optimal monetary policy rules in setups where certainty equivalence does not hold because either central bank preferences are not quadratic, and/or the aggregate supply relation is nonlinear. Analytical results show that these features lead to sign and size asymmetries, and nonlinearities in the policy rule. Reduced-form estimates indicate that US monetary policy can be characterized by a nonlinear policy rule after 1983, but not before 1979. This finding is consistent with the view that the Fed's inflation preferences during the Volcker-Greenspan regime differ considerably from the ones during the Burns-Miller regime.Dans cet article, nous dérivons les règles de politique monétaire optimales dans des cadres où \"l'équivalence certaine\" n'est pas satisfaite. On trouve des cas de ce type lorsque, par exemple, les préférences de la banque centrale ne sont pas quadratiques ou lorsque la relation d'offre agrégée n'est pas linéaire. Les résultats théoriques semblent montrer qu'ils peuvent conduire à des asymétries de signe et de niveau et à des nonlinéarités dans la règle de politique. À partir d'estimations de la forme réduite sur données américaines, nous trouvons que la politique monétaire des États-Unis peut être caractérisée par une règle décisionnelle non linéaire après 1983, mais que ce n'est pas le cas avant 1979. Ces résultats reflètent bien la nette différence d'attitude de la Réserve Fédérale face à l'inflation durant les périodes Volcker-Greenspan et Burns-Miller
A chloroform extract obtained from a decoction of Ficus carica leaves improves the cholesterolaemic status of rats with streptootocin-includede diabetes
The
antidiabetic
effects
of
Ficus
carica
leaf
extracts
have
been
reported
previously.
From
the
aqueous
decoction
of
fig
leaves,
after
treatment
with
HCl,
centrifuging,
treatment
with
sodium
hydroxide
(NaOH)
and
extraction
with
chloroform
(CHCl
3
),
the
administration
of
the
organic
phase
rats
with
streptozotocin-induced
diabetes
led
to
a
decline
in
the
levels
of
total
cholesterol
and
an
decrease
in
the
total
cholesterol/HDL
cholesterol
ratio
(with
respect
to
the
control
group),
together
with
a
reduction
of
the
hyperglycaemia
Confined photon modes with triangular symmetry in hexagonal microcavities in 2D photonic Crystals
We present theoretical and experimental studies of the size and thickness
dependencies of the optical emission spectra from microcavities with hexagonal
shape in films of two-dimensional photonic crystal. A semiclassical plane-wave
model, which takes into account the electrodynamic properties of quasi-2D
planar photonic microcavity, is developed to predict the eigenfrequencies of
the confined photon modes as a function of both the hexagon-cavity size and the
film thickness. Modes with two different symmetries, triangular and hexagonal,
are critically analyzed. It is shown that the model of confined photon modes
with triangular symmetry gives a better agreement between the predicted
eigenmodes and the observed resonances.Comment: 14 pages, 6 figure
Production of carcinogenic acetaldehyde by Candida albicans from patients with potentially malignant oral mucosal disorders
OBJECTIVES: Production of carcinogenic acetaldehyde
by Candida has been suggested to contribute to epithelial
dysplasia and oral carcinogenesis. Oral lichen planus
(OLP), oral lichenoid lesion (OLL) and oral leukoplakia
(OL) are potentially carcinogenic oral diseases where
colonisation by Candida is common, but acetaldehyde
production by Candida has not been studied.
STUDY DESIGN: Acetaldehyde production in ethanol
(11 mM), glucose (100 mM), ethanol–glucose (11 mM
and 100 mM) or red wine (1200 mM ethanol) incubation
by Candida albicans from patients with OLL (n = 6), OLP
(n = 16), OL (n = 6) and controls (n = 6) was measured
by gas chromatography. Participants completed a questionnaire
regarding their smoking habits and alcohol
consumption.
RESULTS: All Candida albicans isolates produced potentially
carcinogenic levels of acetaldehyde (>100 lM) in all
incubations containing ethanol. The control group isolates
produced the highest acetaldehyde levels. Isolates
from smokers produced more acetaldehyde in all incubations
than those from non-smokers. The difference was
significant in ethanol–glucose incubation. Isolates from
patients who were both smokers and drinkers produced
the highest amounts when incubated in ethanol, ethanol–
glucose and wine.
CONCLUSIONS: Candida albicans isolated from potentially
carcinogenic oral diseases can produce mutagenic
amounts of acetaldehyde. Cigarette smoking and alcohol
consumption may favour adaptational changes resulting
in the upregulation of candidal acetaldehyde metabolism.peer-reviewe
Impaired sense of smell in a Drosophila Parkinson's model.
Parkinson’s disease (PD) is one of the most common neurodegenerative disease characterized by the clinical triad: tremor, akinesia and rigidity. Several studies have suggested that PD patients show disturbances in olfaction at the earliest onset of the disease. The fruit fly Drosophila melanogaster 32 is becoming a powerful model organism to study neurodegenerative diseases. We sought to use this system to explore olfactory dysfunction, if any, in PINK1 mutants, which is a model for PD. PINK1 mutants display many important diagnostic symptoms of the disease such as akinetic motor behavior. In the present study, we describe for the first time, to the best of our knowledge, neurophysiological and neuroanatomical results concerning the olfactory function in PINK1 mutant flies. Electroantennograms were recorded in response to synthetic and natural volatiles (essential oils) from groups of PINK1 mutant adults at three different time points in their life cycle: one from 3-5 day-old flies, from 15-20 and from 27-30 days. The results obtained were compared with the same age-groups of wild type flies. We found that mutant adults showed a decrease in the olfactory response to 1-hexanol, α-pinene and essential oil volatiles. This olfactory response in mutant adults decreased even more as the flies aged. Immunohistological analysis of the antennal lobes in these mutants revealed structural abnormalities, especially in the expression of Bruchpilot protein, a marker for synaptic active zones. The combination of electrophysiological and morphological results suggests that the altered synaptic organization may be due to a neurodegenerative process. Our results indicate that this model can be used as a tool for understanding PD pathogensis and pathophysiology. These results help to explore the potential of using olfaction as a means of monitoring PD progression and developing new treatments
Applications of 3D printing in cancer
The tumour heterogeneity and interindividual variability is a major problem when treating cancer as every patient responds in a different way to the current drug therapies. 3D printing is a tool that can hamper the issues faced in cancer patients allowing for individualisation of treatment by the production of in vitro models with micro-environments mimicking more closely real cancer conditions facilitating complex therapies. Further improvements are required, for example the development of biocompatible bioinks or need for vascularisation. The journey from bench to bedside is challenging from the regulatory point of view where the establishment of manufacturing guidelines, quality systems and safety of use and administration of personalised medicines remains unclear. This review will provide an insight in the major applications of 3D printing in cancer both in the development of in vitro cancer models as well as personalised medicines for cancer patients focused on hydrogels and therapeutic implants
Functional and morphological correlates in the drosophila LRRK2 loss-of-function model of Parkinson's disease: drug effects of Withania somnifera (Dunal) administration
The common fruit fly Drosophila melanogaster (Dm) is a simple animal species that contributed significantly to the development of neurobiology whose leucine-rich repeat kinase 2 mutants (LRRK2) loss-of-function in the WD40 domain represent a very interesting tool to look into physiopathology of Parkinson's disease (PD). Accordingly, LRRK2 Dm have also the potential to contribute to reveal innovative therapeutic approaches to its treatment. Withania somnifera Dunal, a plant that grows spontaneously also in Mediterranean regions, is known in folk medicine for its anti-inflammatory and protective properties against neurodegeneration. The aim of this study was to evaluate the neuroprotective effects of its standardized root methanolic extract (Wse) on the LRRK2 loss-of-function Dm model of PD. To this end mutant and wild type (WT) flies were administered Wse, through diet, at different concentrations as larvae and adults (L+/A+) or as adults (L-/A+) only. LRRK2 mutants have a significantly reduced lifespan and compromised motor function and mitochondrial morphology compared toWT flies 1% Wse-enriched diet, administered to Dm LRRK2 as L-/A+and improved a) locomotor activity b) muscle electrophysiological response to stimuli and also c) protected against mitochondria degeneration. In contrast, the administration of Wse to Dm LRRK2 as L+/A+, no matter at which concentration, worsened lifespan and determined the appearance of increased endosomal activity in the thoracic ganglia. These results, while confirming that the LRRK2 loss-of-function in the WD40 domain represents a valid model of PD, reveal that under appropriate concentrations Wse can be usefully employed to counteract some deficits associated with the disease. However, a careful assessment of the risks, likely related to the impaired endosomal activity, is require
Potassium fertilisation and the thermal behaviour of Cynara cardunculus L.
Herbaceous biomass like Cynara is commonly high in potassium, chlorine and ash, which has been reported as a source of problems for combustion applications. An appropriate management of the potassium fertilisation is suggested as a way of improving the quality of the Cynara biomass for solid fuel applications. In this work a factorial experiment was designed involving two types of fertilisers, KCl and K2SO4, and two K rates, in order to study the effect of potassium fertilisation on the composition and thermal behaviour of Cynara biomass.
The results proved that the potassium content of Cynara biomass increases with the potassium fertilisation. The thermogravimetric study showed that sintering phenomena can be expected at temperatures higher than 900 °C when the crop has been highly K-fertilised, irrespective of the type of fertiliser used, KCl or K2SO4. However, the SEM images taken of samples of the four K treatments of this experiment did not reveal signs of ash melting, although some particles with crystalline appearance appeared in the samples from highly K-fertilised treatments
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