1,720,988 research outputs found
SAGGI SULL'APPRENDIMENTO, POLITICA MONETARIA E ASSET PRICES
No full textIn letteratura si assume generalmente che gli agenti siano dotati di perfetta razionalità e quindi siano in grado di anticipare l'evoluzione del sistema economico. Partendo dalla letteratura sull'apprendimento adattivo, si ipotizza che gli agenti si comportino come econometrici, aggiustando le proprie previsioni mano a mano che i dati diventano disponibili. Il primo capitolo analizza l'apprendimento dell'equilibrio da parte degli agenti in presenza di un meccanismo di trasmissione del cost channel. Supponendo che la Banca Centrale operi in regime discrezionale, si osserva che una politica monetaria che risponde all'aspettative garantisce la determinatezza dell'economia solo se la banca centrale dimostra una minor preferenza per la stabilizzazione dell'output. Tuttavia, l'area di determinatezza dell'equilibrio si allarga se la banca centrale stabilizza anche il tasso di interesse. La seconda parte della tesi si concentra invece sul ruolo della stabilità finanziaria nella conduzione della politica monetaria. Sei nei modelli standard di tipo Keynesiano rispondere agli asset prices sortisce degli effetti positivi solo se gli agenti stimano il modello corretto dell'economia, ecco che in presenza di mal specificazione o eterogeneità la banca centrale riesce a raggiungere la stabilità economica attraverso i normali canali. La conclusione si ribalta se il meccanismo di cost channel opera nell'economia.In the literature agents are endowed by full rationality and hence they are able to anticipate the evolution of the economy. On the findings of the adaptive learning literature, we assume that agents behave as econometricians updating their own forecasts by the available data.
In the first essays we analyze the learnability of the equilibrium by agents when the cost channel mechanisms of monetary policy is operating. Under discretion the expectations-based interest rate rule leads the economy to determinacy of the rational expectations equilibrium (REE), only if the degree of preference for economic stability is sufficiently low. On the other hand, the determinacy of REE enlarges if the central bank stabilizes also the interest rate.
The second part of the thesis concerns on the role of financial stability in the conducting of monetary policy. If in the standard New Keynesian model responding to asset prices shows benefits for the economy, the presence of misspecification and heterogeneity leads the economy to indeterminacy and E-instability.
In an economy characterized by wealth effect and cost channel we show that the optimal discretionary monetary policy drive the economy toward the asymptotic convergence of the economy to the fundamental REE
Symptomatic threshold of hypoglycemia and predictors of severe hypoglycemia in children and adolescent with T1DM
No full textObjectives: To evaluate the ability of a group of children and adolescent with T1DM to recognize the state of hypoglycemia and to estimate their hypoglycemic symptomatic threshold (HST). To identify risk factors for the development of severe hypoglycemia. Methods: Forty-five T1DM patients (22 Males) aged 15.1 (5.3) were asked to complete a questionnaire designed to investigate the HST, the type of neuroglycopenic and autonomic symptoms and the frequency of moderate and severe hypoglycemic episodes.The patients were then asked for a three months period to measure and record blood glucose (BG) levels and any hypoglycemic symptom at least four time a day (before and two hours after main meals). HbA1c, Insulin requirement, mean and SD of BG values, low BG (LBGI) and high BG (HBGI) indexes were taken into account.The results are reported as median (IQR). Mann–Whitney, Kruskal– Wallis and simple regression were used for statistical analysis. Results: Forty-five patients completed the questionnaire and 14 (31%) of them reported the three months glucose and hypoglycemic symptoms monitoring. The reported HST was 69 mg/dl in 28/45 (62%), 50 mg/dl in 14/45(31%) and 40 mg/dl in 3/45(7%).The
patients reporting the lowest HST showed significant higher LBGI (p < 0.05). The rate of hypoglycemic values in HBGM in the
previous six months was 7.7% (7.4). The percentage of hypoglycemic values resulted directly related to disease duration (p < 0.05), age (p < 0.02), LBGI (p < 0.002). Four patients (10%) who reported a HST of 69 mg/dl and who declared to be always able to recognize hypoglycemic symptoms, showed, during the previous year, at least one episode of severe hypoglycemia. The patients who showed severe hypoglycemic events have significantly higher BG SD in the last six
months (p < 0.002). Conclusions: In our experience, BG-SD is a predictive parameter of severe hypoglycemic events, while LBGI, HST and prevalence of LBG values do not appear to be reliable risk indicators
Hyperthyrotropinemia of the Preterm Newborn: Treat or Not to Treat?
No full textBackground: It is often difficult to establish whether
hyperthyrotropinemia in preterm newborn is a simple physiologic
energy sparing phenomenon or a true hypothyroidism requiring
replacement treatment. Objective and hypotheses: This study
aimed to find in what extent thyroid function in the preterm
newborn can be influenced by clinical characteristics and
complications. Method: We studied 35 preterm newborn,
gestational age (GA) 32.0 (2.1) weeks, 21 males, 13 small for
gestational age (SGA), positive at TSH neonatal screening and
with persistent hyperthyrotropinemia during hospitalization.
We collected the following clinical data: GA, type of delivery,
birth weight (BW), length (BL) and head circumference, clinical
complications (RDS, jaundice, infections), time of detection and
level of the pathologic TSH value in the dried blood spot (DBS)
and in the serum sample, time of starting L-thyroxine and its
dosage at steady state. Data are reported as median (IQR). Mann-
Whitney test and simple regression were applied for statistical
analysis. Results: TSH levels and time of detection of pathologic
values were not correlated to GA, BW, length and head
circumference. SGA showed lower serum TSH levels (14.6 (5.1)
mU/ml vs 22.6 (69.9) mU/ml; P!0.05). The patients with RDS
showed lower TSH levels compared with patients without RDS
(14.6 (7.9) mU/ml vs 24.0 (66) mU/ml; P!0.05) and required lower
L-Thyroxine dosage at steady state (6.6 (4.0) vs 10.0 (2.0) mg/kg
per day; P!0.05). The starting time of replacement treatment was
inversely correlated to BW and BL (P!0.05) but was not different
in SGA compared to appropriate for gestational age newborns.
The patients who received replacement treatment had significantly
higher pretreatment TSH in serum (18.11 (65.07) mU/ml vs 11.55
(10.83) mU/ml; P!0.02) but not in DBS (10.0 (23.75) mU/ml vs
6.69 (3.05) mU/ml; PO0.05). Conclusion: Our results support the
hypothesis that subclinical hypothyroidism could play a protective
effect on growth and respiratory function in the preterm newborn.
Further studies are needed to determine whether or not to
undertake replacing therapy
Dealing with Financial Instability under a DSGE modeling approach with Banking Intermediation: a predictability analysis versus TVP-VARs
Full text linkIn DSGE literature there has been an increasing awareness on the role that the banking sector can play in macroeconomic activity. In most of recent works, purely financial instabilities and frictions are derived from intermediaries that affect the real economy by means of a credit channel or a balance sheet channel. We model financial intermediation as in Gertler and Karadi (2011) to take into account the bank leverage constraint in the propagation of shocks to the real economy. Within this framework, the evolution of estimated shocks and the instabilities in the structural parameters show that time-variation should be crucial in any attempted empirical analysis. However, DSGE modelling usually fails to take into account inherent nonlinearities of the economy, especially in crisis time periods. Hence, we propose a novel time-varying parameter (TVP) state-space estimation method for VAR processes both for homoskedastic and heteroskedastic error structures. We conduct an exhaustive empirical exercise that includes the comparison of the out-of-sample predictive performance of the estimated DSGE model with that of standard VARs, Bayesian VARs and TVP-VARs. Overall, a first attempt is made to find macro-financial micro-founded DSGE models as well as adaptive TVP-VARs, which are able to deal with financial instabilities via incorporating banking intermediation.European Commission - Seventh Framework Programme (FP7
A rare complication of T1DM in a female teenager: Mauriac syndrome?
No full textObjective: To report a case of Mauriac syndrome. Methods: A 14-year old F patient was referred to our Clinic for poor
glycemic control and progressive insulin resistance. She was diagnosed with T1DM at 8 years old. After the first 2 years of MDI she underwent CSII due to progressive increase in insulin requirement (0.66->1.46 units/kg). However compliance was very poor and led the patient to be frequently hospitalized (2 DKA) and soon after to replace the therapy back. In spite of frequent manipulations in insulin dosing,our patient showed progressive worsening of metabolic control (HbA1c 8.72->10.9%) and follow-up drop-out. In March 2015 she was referred to our clinic for a further worsening of glycemic control. Results: Height,weight and BMI resulted below than 3rdcentile for age (respectively 146.2 cm/34.1 kg/16 kg/m2). She had delayed puberty (B2,PH1). Laboratory investigations described increased liver enzymes (ASAT/ALAT/GGT:590/435/328 U/L),elevated lactate level (72 mg/dl) and IGF-1 < 3rd centile. Abdominal ultrasound revealed hepatomegaly with steatohepatosis. Pelvic features confirmed prepubertal status. Microalbuminuria and retina examination were normal. During hospitalization our patient started psychological interviews, which revealed her disease refusal (frequently skipped insulin injections, uncontrolled snacks and glycemic controls performed to friends in order to simulate adequate compliance). Investigations about hepatomegaly excluded infectious diseases, autoimmune, metabolic, obstructive and oncologic causes. Coeliac disease screening was negative. DXA demonstrated Zscore -3,2. Brain MRI was normal. After 2 weeks we observed a significant reduction of HbA1c (7.9%), ASAT and ALAT (140/219 U/L). Conclusions: According to the presented data we confirmed the presence of Mauriac syndrome. This is a rare complication related to under-insulinisation. It includes short stature, glycogen laden enlarged liver, limited joint mobility, tight waxy skin and delayed puberty
Ultra long-acting degludec versus long-acting insulin glargine in children and teenagers with type 1 diabetes
No full textObjectives: Unstable metabolic control and frequent hypoglycemic
events are the main indications of switching from long-acting insulin
glargine to ultra long-acting insulin degludec. The aim of the present
study is to evaluate the efficacy of such a switch in children and
adolescents.
Methods: We enrolled retrospectively 58 children and adolescents
with type 1 diabetes divided into two groups matched for age, sex
and metabolic control. Group A was switched from glargine to degludec
while group B continued treatment with glargine. We compared
HbA1c, percent of BG detections below 60 mg/dl, mean and SD of
home blood glucose monitoring (HBGM), HBGI and LBGI during the
three months before and after switching from one to the other insulin
in group A and during the corresponding period in group B. Data
are reported as median (IQR). Chi square and Mann–Whitney test
were used for statistical analysis.
Results: During the three months after switching the percentage of
patients who improved the HbA1c was higher in group A then in
group B. We didn’t find any statistical significant difference between
the two groups for any parameter taken into account. In particular
group A didn’t showed any statistically significant reduction of hypoglycemic
events after switching (see table).
Conclusions: According to our preliminary results the transition from
long-acting insulin glargine to insulin ultra long-acting degludec in
pediatric patients with T1DM does not seem to be able to significantly
improve the metabolic control and reduce the risk of
hypoglycemia
Assessment of the efficacy of a psychological aiming at improving the quality of life in patients with diabetes mellitus type 1 and their families
No full textObjectives: To assess the efficacy of a psychological intervention at
disease onset in pediatric patients with T1DM and their families.
Methods: Two groups of 14 patients matched for age and gender
were compared: A (newly diagnosed patients) and B (one year of
disease duration). The patients and their families were assessed
through questionnaire (CBCL) at the time of the diagnosis (T1) in
group A and after one year of disease (T2) in both groups. Since the
beginning of disease and the whole first year group A received a
psychological support treatment. The distribution of anxiety, somatic
and internalization scales of CBCL were compared in groupA at disease
onset and after one year and between the two groups at one
year of disease duration. Kruskal-Wallis test was used for statistical
analysis.
POSTER TOURS 161
Results: GroupA showed a significant improvement of the anxiety,
somatic and internalization scales during the first year of disease.
After one year of disease Group A compared to group B showed non
statically significant lower anxiety, somatic and internalization score
(see table).
Conclusions: The study showed that, at the time of the diagnosis
and during the first weeks, patients and their families have a lower
adjustment due to the traumatic experience of the diagnosis. Over
time they seem to better adjust to the situation. The study
was however not able to demonstrate a clear effectiveness of the
psychological support intervention started at the onset of the
disease
Bone metabolism and glucose control in children and adolescents with T1DM
No full textObjectives: Experimental studies suggested that undercarboxylated osteocalcin (GluOC) is directly related to insulin sensitivity and secretion. Aim of the present study was to evaluate whether in type 1diabetic children and adolescents the glycemic control is influenced by the bone metabolism. Methods: We studied 79 DMT1 patients (45 male), age 14(7) years, disease duration 59(49) months, HbA1c 7.8(1.2)%, insulin requirement 0.8(0.3) U/kg/day; 12 patients were treated with CSII and 57 with MDI. In all patients we measured: height (H), weight, waist circumference (WC), L2-L4 spine and total bodyBMD(evaluated by DXA), serum levels of calcium, phosphate, magnesium, alkaline phosphatase, PTH, 25-OH-D, undercarboxylated (GluOC) and carboxylated osteocalcin (GlaOC). Data are reported as median (IQR). Mann–Whitney, simple and multiple regressions were used for statistical analysis. Results: We divided our patients according to the metabolic control in two groups: Group A (good control – HbA1c ≤7.5%) and Group B (poor control – HbA1c >7.5%). Group B showed significantly lower levels of 25-hydroxy vitamin D (23.6 ng/ml (12.6) vs. 18.6 ng/ml (13.2); p < 0.01). Alkaline phosphatase resulted inversely correlated to GluOC adjusted for age (p < 0.05) and to GluOC/GlaOC ratio (p < 0.01). L2-L4 (p < 0.0001) and total body (p < 0.0002) BMD ZScore were both highly directly correlated to SDS-BMI.WC/H ratio resulted directly correlated to GluOC/GlaOC ratio (p < 0.01) and inversely correlated to GlaOC adjusted for age (p < 0.01). Conclusion: Our results support the hypothesis of a favorable effect of vitamin D on insulin/glucose balance in children and adolescents with T1DM, with no evidence of significant effect of exogenous insulin and metabolic control on osteocalcin levels and bone density. Furthermore our study confirms inverse correlation between osteocalcin and visceral fat, previously reported both in mice and humans
Peripheral nerve conduction study in children and adolescents at the clinical onset of type 1 diabetes and at five of more years postdiagnosis
No full textOnset of type 2 diabetes in a toddler ?
No full textObjectives: To report a case of a normal weight Italian girl who
showed temporary diabetes in two occasions, neonatally and at the
age of two year, and successive later development of overt diabetes
of uncertain classification.
Case report: FP is the eldest daughter of a caucasian couple, born
at the end of normal pregnancy by natural delivery with a birth
weight adequate to gestational age. In the first week of live she
showed temporary hyperglycemia, glycosuria and ketonuria. Insulin
and C-peptide in serum resulted respectively 0.5 mcU/mL and < 0.3
mcg/ml. Blood glucose (BG) monitoring was started showing mainly
normoglycemia with occasional high-borderline BG values with
HbA1c in the normal range. KCNJ11 and MODY2 were excluded by
genetic test. At 2 years of life hyperglycemia, ketonuria and HbA1
of 6.9% were documented and insulin treatment was started, and
discontinued after two weeks, for complete spontaneous remission.
T1DM related antibodies (ICA, GADA, IAA, IA2, ZNT8) and HLA D3
and D4 antigens were all negative and an IVGTT showed a FPIR of
47 mcU/mL (1st centile). NGS identified two variant of the HNF1-α
gene: 79A > C (pIle27Leu) reported as associated with insulin resistance,
and G1720A > G (pSer574Gly) associated with increased risk
of type 2 diabetes. At the age of 8 year the girl developed over diabetes
(HbA1 of 8.4%, CGM reported a BG value (mean SD) of
152 40 mg/dl and a maximun glycemic value of 311 mg/dl). On
the basis of the genetic results we started treatment with metformin
(initial dose: 250 mg OD, final dose: 500 mg BID) with a progressive
reduction of both fasting and postprandial glycemia
(mean sd BG by CGM 125.5 32.1 mg/dl).
Conclusions: The interest of this case arises from the difficulty, even
in the presence of overt diabetes, to find a correct diagnostic and
therapeutic orientation. The good therapeutic response to metformin
and genetic mutations suggest the hypothesis of an exceptionally
early onset of type 2 diabetes
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