960 research outputs found
L-optimal transportation for Ricci flow
No full textWe introduce the notion of L-optimal transportation, and use it to construct a natural monotonic quantity for Ricci flow which includes a selection of other monotonicity results, including some key discoveries of Perelman [13] (both related to entropy and to L-length) and a recent result of McCann and the author [11]
IgM thyroglobulin autoantibodies are detectable in serum of patients with subacute thyroiditis
No full textIgM thyroglobulin autoantibodies are detectable in serum of patients with subacute thyroiditis
Debora Ricci, Alessandro Brancatella, Michele Marinò, Paolo Vitti and Francesco Latrofa
Department of Clinical and Experimental Medicine, Endocrinology Unit, University Hospital of Pisa, Italy
Context. Subacute thyroiditis (SAT) is an inflammation of the thyroid, likely caused by a viral infection. IgG Autoantibodies (Ab) to the main thyroid antigens, including thyroglobulin (Tg) (TgAb) have been reported in a few patients with SAT and their appearance is usually transient. We investigated whether IgM TgAb can be detected in sera of patients with SAT.
Design. Serum samples were collected from 17 patients with SAT, 10 with Graves’ disease (GD) and 10 with Hashimoto’s thyroiditis (HT). GD and HT sera were selected because of positive IgG TgAb (by AIA-PACK 2000, Tosoh Biosciences). Samples of SAT patients were collected 1-9 months after the onset of SAT.
IgG and IgM TgAb were measured in ELISA. Wells coated with human Tg were incubated with sera and IgG and IgM TgAb were detected with biotin-conjugated anti human IgG or IgM. HRPO- conjugated streptadivin was then added. The substrate was o-phenylene diamine + H2O2. ODs were read at 490 nm.
To rule out non-specific binding, ELISA for IgM was performed with BSA, keyhole limpet hemocyanin (KLH) and glucagon (Gluc); sera showing BSA binding were considered as IgM TgAb negative.
Results. IgG TgAb were positive in 14/17 SAT, 10/10 GD and 10/10 HT. IgM TgAb were positive in 10/17 SAT, 0/10 GD and 0/10 HT. Seven SAT sera were IgG TgAb positive and IgM TgAb negative, 5 IgG TgAb negative and IgM TgAb positive and 5 IgG TgAb positive and IgM TgAb positive. Median titer was 1/100 (IQR: 1/33-1/1000) for IgG TgAb and 1/3300 (IQR: 1/3300-1/3300) for IgM TgAb. The duration of SAT did not correlate with positive IgM TgAb. All SAT sera did not bind KLH and Gluc in IgM ELISA.
Conclusions. IgM TgAb can be detected in sera of SAT patients with or without IgG TgAb. They do not correlate with the duration of SAT
Asymptotically non-negative Ricci curvature, elliptic Kato constant and isoperimetric inequalities
No full textThe ABP method for proving isoperimetric inequalities has been first employed by Cabré
in R n, then developed by Brendle, notably in the context of non-compact Riemannian
manifolds of non-negative Ricci curvature and positive asymptotic volume ratio. In this
paper, we expand upon their approach and prove isoperimetric inequalities (sharp in the
limit) in the presence of a small amount of negative curvature. First, we consider smallness of the negative part Ric− of the Ricci curvature in terms of its elliptic Kato constant.
Indeed, the Kato constant turns out to control the non-negativity of the (∞)- Bakry-Émery
Ricci-tensor of a suitable conformal deformation of the manifold, and the ABP method can
be implemented in this setting. Secondly, we show that the smallness of the Kato constant
is ensured provided that the asymptotic volume ratio is positive and either M has one end
and asymptotically non-negative sectional curvature, or there is a suitable polynomial
decay of Ric−, and the relative volume comparison condition known as (VC) holds. To
show this latter fact, we enhance techniques elaborated by Li-Tam and Kasue to obtain
new estimates of the Green function valid on the whole manifol
Effect of thyroglobulin autoantibodies on the clearance of serum thyroglobulin in humans
No full textEffect of thyroglobulin autoantibodies on the clearance of serum thyroglobulin in humans
Francesco Latrofa, MD1, Debora Ricci, PhD1, Sara Bottai, MD1, Paolo Piaggi, PhD2,
Michele Marinò, MD1, Paolo Vitti, MD1
1Endocrinology Unit I, Department of Clinical and Experimental Medicine,
University Hospital of Pisa, Italy
2Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, AZ
To establish whether TgAb influence Tg clearance in humans, we correlated serum TgAb and Tg shortly after 131I treatment.
Samples were taken at the time of 131I treatment and at intervals of 15 days thereafter (up to 90 days) in 30 consecutive patients undergoing 131I treatment because of Graves’ hyperthyroidism. Tg was measured by an IMA (functional sensitivity 0.1 ng/mL), TgAb by an IMA (analytical sensitivity 6 IU/mL).
Tg was detectable in all patients at day 0. The concentrations of Tg rose from 33.2 (17.8-61.0) ng/mL at day 0 to 214.6 (116.9-393.4 ng/mL) at day 30 and then steadily decreased, reaching the lowest concentration at day 90 (10.9 [5.5-20.9] ng/mL). Compared to their levels at day 0 (23.6 [10.5-52.9] IU/mL), TgAb remained stable through 15 day and then gradually increased up to 116.6 (51.9-262.2) IU/mL at day 90. Patients were then split into two groups: with undetectable (<6 UI/l) (9 patients) or detectable (≥6) (21 patients) TgAb at day 0. Compared to the other cohort, patients with detectable TgAb showed significantly lower Tg concentrations at day 0 (20.3 [10.1-40.2] vs. 101.8 [36.6-279.8] ng/mL), similar at day 15, lower at day 30 (146.5 [74.3-287.8] vs. 514.8 [187.8-1407.9] ng/mL), at day 45 (87.5 [43.1-176.6] vs. 337.9 [120.1-947.0] ng/mL), at day 60 (61.6 [31.0-121.4] vs. 255.8 [79.0-823.8] ng/mL) and at day 75 (24.5 [11.9-49.2] vs. 249.5 [63.5-971.1] ng/mL) and similar at day 90. Compared to other patients, those with detectable TgAb showed a lower (182.5 [92.0-361.0] vs. 514.8 [187.8-1407.9] ng/mL) and an earlier (day 15 vs. day 30) peak of Tg. The mean of AUC of Tg concentrations was higher in patients with undetectable TgAb (36883 ± 44625 ng/mL) compared to the other group (17340 ± 16481 ng/mL) (p=0.02).
In conclusion, TgAb modify the changes in Tg concentrations observed immediately after 131I treatment, inducing lower levels and a precocious peak of Tg. These observations indicate that TgAb influence significantly Tg clearance in humans because they remove Tg from serum and support the concept that TgAb interference on Tg measurement is mainly due to an in vivo effect and not to analytical interference
Overeducation: Nuove evidenze empiriche
No full textL’offerta di diplomati e di laureati è aumentata negli ultimi anni sotto la spinta del processo di Lisbona prima e di Europa 2020 poi. La percentuale dei laureati è quasi triplicata nella coorte più giovane di età. Al contempo, la crisi economica e la diffusione di forme di lavoro atipiche non lasciano molte speranze per uno sviluppo armonioso della domanda di alte qualifiche. L’evidenza aneddotica sull’overeducation è sempre più preoccupante. Questo saggio fornisce una nuova evidenza empirica sul fenomeno utilizzando 5 indicatori di overeducation contenuti nella indagine Isfol Plus relatica al 2014. La definizione Cedefop e l’uso delle sole interviste dirette garantiscono una maggiore accuratezza della misura fornita. Il quadro che emerge è meno preoccupante per l’overeducation e più preoccupante per l’overskilling di quello di altre indagini precedenti. Sia l’undereducation che l’underskilling sono di dimensioni modeste. Il titolo di studio protegge sempre meno sia i laureati che ancora di più i diplomati. Gli indicatori oggettivi forniscono un quadro più preoccupante, ma riflettono anche una tendenza a sovrastimare il fenomeno per definizione. L’indicatore composito suggerisce che solo meno del 10% sono casi indiscutibili di educational mismatch. Un 30-40 per cento sono casi di mismatch parziale, vale a dire sotto solo alcune delle dimensioni considerate. I fattori dal lato dell’offerta puntano ad un sistema di istruzione scolastico ed universitario incapace di fornire competenze lavorative adeguate, in linea con l’interpretazione più recente dell’educational mismatch come fondato sulla teoria del capitale umano. I fattori dal lato della domanda evidenziano il carattere tradizionale del sistema produttivo e la necessità di stimolare l’assuzione di diplomati e laureati con incentivi alla ricerca e allo sviluppo e con la creazione di spin off e altre forme di aiuto all’innovazione d’impresa
Thyroglobulin Autoantibodies arise before Thyroperoxidase Autoantibodies in Juvenile Autoimmune Thyroiditis
No full textThyroglobulin Autoantibodies arise before Thyroperoxidase Autoantibodies in Juvenile Autoimmune Thyroiditis
Valentina Verdiani, Debora Ricci, Paolo Piaggi, Michele Marinò, Teresa Rago, Paolo Vitti, Francesco Latrofa
Department of Clinical and Experimental Medicine, University of Pisa; Phoenix Epidemiology and Clinical Research Branch, National Institutes of Health, Phoenix, AZ
Context. Juvenile Autoimmune Thyroiditis (JAT) is characterized by positive thyroid autoantibodies (thyroglobulin autoantibodies –TgAb and thyroperoxidase autoantibodies –TPOAb), hypoecogenic pattern at thyroid thyroid ultrasound (US) and above-normal TSH levels. Aim of the study was the clinical characterization of JAT, to identify which clinical manifestation appears first.
Design. We investigated ≤14 yr-old subjects who had undergone measurement of thyroglobulin autoantibodies (TgAb) and/or thyroperoxidase autoantibodies (TPOAb) in the period 2003-2013 because of a suspected JAT. The subjects with normal laboratory and US findings as well as patients with non-autoimmune thyroid disease associated with positive TgAb and/or TPOAb and patients with Graves’ disease were excluded. The remaining 205 subjects (M = 81, F = 124; age= 8.4 ± 3.3 yrs) showed one or more thyroid abnormal features (positive TgAb, positive TPOAb, hypoecogenic pattern at thyroid US, above-normal TSH level).
Results. 54.6% of subjects showed negative TgAb and TPOAb, 30.7% positive TgAb and TPOAb, 12.7% positive TgAb and negative TPOAb and 2.0% positive TPOAb and negative TgAb. A hypoechogenic pattern at thyroid US was observed in 53.3% of juveniles and a previous or current above-normal TSH level in 53.2% of them. Both positive TgAb and positive TPOAb correlated with the hypoechogenic pattern (p = 0.024 and p <0.001 respectively). About 50% of the juveniles with positive TgAb, about 50% of those with positive TPOAb and about 50% of those with hypoechogenic pattern had abnormal TSH levels; none of them correlated with an above-normal TSH levels more than the others. About 70% of ≤4 yr-old juveniles showed high TSH levels in the absence of other thyroid abnormalities (“isolated hyperthyrotropinemia"). Positive thyroid autoantibodies were first observed in the group of 4-6 yr-old juveniles and were confirmed at later ages. The percentage of positive TgAb was higher compared to positive TPOAb for all age groups, although the differences lowered with age. The hypoecogenic pattern was observed in a few 2-4 yr old juveniles and was more frequent (up to 60%) in the older groups. The age distribution was different for positive TgAb (p <0.001), positive TPOAb (p <0.001), hypoechogenic pattern (p <0.001) and above-normal TSH levels (p = 0.003).
Conclusions. 1) JAT is extremely rare in < 4 yr-old juveniles; at this age and above-normal TSH level identifies the "isolated hyperthyrotropinemia"; 2) in JAT the appearance of TgAb precede that of TPOAb, pointing to the value of TgAb measurement in the diagnostic work-up of JAT and suggesting that the response to Tg is the prime event of B-cell response in JAT; 3) the value of ultrasonography for the diagnosis of JAT remains unclear
Index and first Betti number of f-minimal hypersurfaces: general ambients
No full textWe generalize a method by L. Ambrozio, A. Carlotto, and B. Sharp to study the Morse
index of closed f-minimal hypersurfaces isometrically immersed in a general weighted
manifold. The technique permits, in particular, to obtain a linear lower bound on the Morse
index via the frst Betti number for closed f-minimal hypersurfaces in products of some
compact rank one symmetric spaces with an Euclidean factor, endowed with the rigid
shrinking gradient Ricci soliton structure. These include, as particular cases, all cylindric
shrinking gradient Ricci solitons
Overeducation after the Supply Push in Italy. A Fresh Look at Five Indicators and a Proposal of a New Opposite Indicator
No full textL’offerta di diplomati e di laureati è aumentata negli ultimi anni sotto la spinta del processo di Lisbona prima e di Europa 2020 poi. La percentuale dei laureati è quasi triplicata nella coorte più giovane di età. Al contempo, la crisi economica e la diffusione di forme di lavoro atipiche non lasciano molte speranze per uno sviluppo armonioso della domanda di alte qualifiche. L’evidenza aneddotica sull’overeducation è sempre più preoccupante. Questo saggio fornisce una nuova evidenza empirica sul fenomeno utilizzando 5 indicatori di overeducation contenuti nella indagine Isfol Plus relatica al 2014. La definizione Cedefop e l’uso delle sole interviste dirette garantiscono una maggiore accuratezza della misura fornita. Il quadro che emerge è meno preoccupante per l’overeducation e più preoccupante per l’overskilling di quello di altre indagini precedenti. Sia l’undereducation che l’underskilling sono di dimensioni modeste. Il titolo di studio protegge sempre meno sia i laureati che ancora di più i diplomati. Gli indicatori oggettivi forniscono un quadro più preoccupante, ma riflettono anche una tendenza a sovrastimare il fenomeno per definizione. L’indicatore composito suggerisce che solo meno del 10% sono casi indiscutibili di educational mismatch. Un 30-40 per cento sono casi di mismatch parziale, vale a dire sotto solo alcune delle dimensioni considerate. I fattori dal lato dell’offerta puntano ad un sistema di istruzione scolastico ed universitario incapace di fornire competenze lavorative adeguate, in linea con l’interpretazione più recente dell’educational mismatch come fondato sulla teoria del capitale umano. I fattori dal lato della domanda evidenziano il carattere tradizionale del sistema produttivo e la necessità di stimolare l’assuzione di diplomati e laureati con incentivi alla ricerca e allo sviluppo e con la creazione di spin off e altre forme di aiuto all’innovazione d’impresa
Leonardo Ricci
No full textBiografia dell'architetto fiorentino Leonardo Ricci e analisi delle sue opere principali e del suo straordinario impegno etico, civile e didatticoThe Florentine architect Leonardo Ricci was an extraordinary teacher at the University in Florence and the United States and is the author of some of the most interesting architectural works of the 20th century. in Ital
On special Riemannian -manifolds with distinct constant Ricci eigenvalues
No full textsummary:The first author and F. Prufer gave an explicit classification of all Riemannian 3-manifolds with distinct constant Ricci eigenvalues and satisfying additional geometrical conditions. The aim of the present paper is to get the same classification under weaker geometrical conditions
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