Optimizing airborne wind energy with reinforcement learning.

Airborne wind energy is a lightweight technology that allows power extraction from the wind using airborne devices such as kites and gliders, where the airfoil orientation can be dynamically controlled in order to maximize performance. The dynamical complexity of turbulent aerodynamics makes this optimization problem unapproachable by conventional methods such as classical control theory, which rely on accurate and tractable analytical models of the dynamical system at hand. Here we propose to attack this problem through reinforcement learning, a technique that-by repeated trial-and-error interactions with the environment-learns to associate observations with profitable actions without requiring prior knowledge of the system. We show that in a simulated environment reinforcement learning finds an efficient way to control a kite so that it can tow a vehicle for long distances. The algorithm we use is based on a small set of intuitive observations and its physically transparent interpretation allows to describe the approximately optimal strategy as a simple list of manoeuvring instructions.

Interrelationship between serum and sputum inflammatory mediators in chronic obstructive pulmonary disease.

Little is known about airway inflammatory markers in chronic obstructive pulmonary disease (COPD). The objective of the present study was to identify and try to correlate pulmonary and peripheral blood inflammatory markers in COPD. In a cross-sectional study on patients with stable COPD, induced sputum and blood samples were collected for the determination of C-reactive protein, eosinophilic cationic protein, serum amyloid A protein, alpha-1 antitrypsin (alpha-1AT), and neutrophil elastase. Twenty-two patients were divided into two groups according to post-bronchodilator forced expiratory volume in the first second (%FEV1): group 1 (N = 12, FEV1 <40%) and group 2 (N = 10, FEV1 > or =40%). An increase in serum elastase, eosinophilic cationic protein and alpha-1AT was observed in serum markers in both groups. Cytology revealed the same total number of cells in groups 1 and 2. There was a significantly higher number of neutrophils in group 1 compared to group 2 (P < 0.05). No difference in eosinophils or macrophages was observed between groups. Serum elastase was positively correlated with serum alpha-1AT (group 1, r = 0.81, P < 0.002 and group 2, r = 0.83, P < 0.17) and negatively correlated with FEV1 (r = -0.85, P < 0.03 and -0.14, P < 0.85, respectively). The results indicate the presence of chronic and persistent pulmonary inflammation in stable patients with COPD. Induced sputum permitted the demonstration of the existence of a subpopulation of cells in which neutrophils predominated. The serum concentration of all inflammatory markers did not correlate with the pulmonary functional impairment.

Interrelationship between serum and sputum inflammatory mediators in chronic obstructive pulmonary disease

Little is known about airway inflammatory markers in chronic obstructive pulmonary disease (COPD). The objective of the present study was to identify and try to correlate pulmonary and peripheral blood inflammatory markers in COPD. In a cross-sectional study on patients with stable COPD, induced sputum and blood samples were collected for the determination of C-reactive protein, eosinophilic cationic protein, serum amyloid A protein, a-1 antitrypsin (a-1AT), and neutrophil elastase. Twenty-two patients were divided into two groups according to post-bronchodilator forced expiratory volume in the first second ( percentFEV1): group 1 (N = 12, FEV1 <40 percent) and group 2 (N = 10, FEV1 ³40 percent). An increase in serum elastase, eosinophilic cationic protein and a-1AT was observed in serum markers in both groups. Cytology revealed the same total number of cells in groups 1 and 2. There was a significantly higher number of neutrophils in group 1 compared to group 2 (P < 0.05). No difference in eosinophils or macrophages was observed between groups. Serum elastase was positively correlated with serum a-1AT (group 1, r = 0.81, P < 0.002 and group 2, r = 0.83, P < 0.17) and negatively correlated with FEV1 (r = -0.85, P < 0.03 and -0.14, P < 0.85, respectively). The results indicate the presence of chronic and persistent pulmonary inflammation in stable patients with COPD. Induced sputum permitted the demonstration of the existence of a subpopulation of cells in which neutrophils predominated. The serum concentration of all inflammatory markers did not correlate with the pulmonary functional impairment.

Monitoring of neuronal and glial calcium activity using a novel direct-contact probe.

In vivo neuronal and glial calcium activity was monitored using a novel direct-contact probe that was designed for fluorescence detection deep within biological tissue. A small diameter fibre bundle direct-contact probe was employed with a laser scanning confocal microscope to detect evoked neuronal and glial activity in the posteromedial barrel subfield of the rat somatosensory cortex in vivo. Resolution of the probe allowed discrimination of single cells, and calcium dynamics spanning milliseconds to several seconds were observed. Initial results indicate that the probe has useful practical applications in the imaging of individual cells and monitoring rapid calcium fluctuations within their cell body and large processes.

Optic fibre bundle contact imaging probe employing a laser scanning confocal microscope.

A small diameter (600 micro m) fused optic fibre imaging bundle was used as a probe to compare fluorescent specimens by direct contact imaging using both a conventional fluorescence microscope and a laser scanning confocal microscope (LSCM) system. Green fluorescent polyester fibres placed on a green fluorescent cardboard background were used to model biological tissue. Axial displacement curves support the hypothesis that pinhole size in the LSCM system reduces the contribution of non-focal plane light. Qualitative comparison showed that the LSCM system produced superior image quality and contrast over the conventional system. The results indicate that the new LSCM-probe combination is an improvement over conventional fluorescence-probe systems. This study shows the feasibility of employing such a small diameter probe in the investigation of biological function in difficult to access areas.

Bilateral testicular adrenal rest tissue in congenital adrenal hyperplasia: US and MR features.

We describe magnetic resonance (MR) and ultrasonography (US) features of bilateral testicular adrenal rest tissue in a 20-yr-old man with congenital adrenal hyperplasia (CAH). Scrotal ultrasonology detected bilateral homogeneous hypoechoic lesions with well-defined margins and without evidence of sound attenuation. MR is useful in defining the size of lesions, because the contrast resolution is better than with sonography and allows an accurate definition of the extent of disease. This case suggests that US evaluation should be included in periodical follow-up of patients with CAH, while MR may be used in the case of rapid increase in the size of the testicular mass.

A new sensor for monitoring chest wall motion during high-frequency oscillatory ventilation.

The recently developed technique of fibre optic respiratory plethysmography (FORP) has been modified to monitor the rapid, small amplitude movements of the chest wall during high-frequency oscillatory ventilation (HFOV). The FORP sensor is an expandable belt encircling the chest, in which is housed a fibre optic loop that alters its radius of curvature as a function of chest perimeter. These curvature changes cause variations in macrobending losses of light transmitted through the fibre, which are proportional to the chest perimeter. Dynamic measurement of transmitted light intensity can hence be used to monitor chest wall motion (CWM). For application to HFOV, the design of the FORP belt was altered to increase sensitivity and the materials were chosen to maximise macrobending effects induced by the CWM. FORP was tested in four piglets ventilated with HFOV, both in the normal and surfactant-deficient lung. Measurement of CWM was possible over the full range of tidal volumes and ventilation frequencies used during HFOV. In all cases, the measured frequency of the CWM fell within 3% of the applied ventilation frequency. In addition, the technique was sufficiently sensitive to detect changes in the amplitude of CWM in response to changes in applied tidal volume. It is anticipated that application of this new non-invasive measurement device will lead to an increased understanding of the dynamics of chest and abdominal wall motion during HFOV.

A new fibre optic sensor for respiratory monitoring.

A new fibre optic plethysmograph has been designed to monitor respiration non invasively. The device incorporates the idea of using thoracic and abdominal belts similar to conventional inductance plethysmography but uses an optical fibre woven into the belts rather than the usual coiled wire. The fibre optic belts incorporate a loop design in the fibre and rely on "macrobending" losses from laser light transmitted down the fibre when the bend radius of the loop changes during respiration. Changes in lung volume are monitored by analysing the relatively large resultant changes in light transmitted through the fibre. The output from the light detector has been interfaced to a computer containing a data acquisition card and the resultant intensity trace is monitored in real time using a virtual instrument created using LabVIEW graphical programming. Preliminary results suggest a highly sensitive system capable of detecting small changes in lung volume using a technique which is not susceptible to electrical noise and which is electrically safe.

Development of autoimmune thyroid diseases during long-term treatment of hematological malignancies with alpha-interferons.

In recent years recombinant alpha-interferons (alpha-IFNs) have been widely used in the treatment of several hematological malignancies. Prolonged courses of IFN have been shown to induce autoantibodies and to support the exacerbation or even the development of autoimmune diseases. In this report we describe the development of symptomatic autoimmune thyroid diseases in 4 (7.4%) out of 54 patients in chronic treatment with recombinant alpha-IFNs in our department. Two patients developed a disease resembling Hashimoto's thyroiditis after 17 and 49 months of continuous IFN treatment, while the other two developed a typical Graves' disease after 41 and 52 months of therapy. The mechanism by which IFN induces autoimmune thyroid diseases, the choice of searching for anti-thyroid autoantibodies before starting long-term IFN treatment, the option of discontinuing IFN therapy in the presence of overt thyroid diseases, and the management of these diseases are discussed.

Concurrent Plummer's disease and parathyroid adenoma. Diagnostic and therapeutic approaches to a difficult clinical problem.

When mild asymptomatic hypercalcemia occurs in a patient with hyperthyroidism, it may or may not be due to concurrent hyperparathyroidism and at times only the control of the hyperthyroidism will resolve the problem. Moreover, the presence of hyperfunctioning thyroid nodules will interfere with Tl-201/Tc-99m pertechnetate parathyroid scintigraphy. Initial treatment of hyperthyroidism with I-131 in this situation controls hyperthyroidism and permits successful localization of parathyroid adenomas, which may then be excised--a result that was achieved in three cases.

[Autoimmune polyendocrinopathy and chronic mucocutaneous candidiasis]. / Poliendocrinopatia autoimmune e candidiasi mucocutanea cronica.

A chronic mucocutaneous infection due to yeasts to the Candida genus can be part of the autoimmune polyglandular syndrome, described as APECS, APECED, SPA type I, CES. The authors describe the case of a young patient affected by mucocutaneous candidiasis, hypoparathyroidism and adrenal insufficiency. Chronic mucocutaneous candidiasis was diagnosed first in early childhood and was followed by the development of hypoparathyroidism (4 yrs) and adrenal insufficiency (5 yrs). The initial lesion of this syndrome is still unknown as the reason of the marked susceptibility to mucocutaneous candidiasis without systemic candidiasis. The treatment of mucocutaneous candidiasis has been improved by the introduction of orally active antifungal drugs as Ketoconazole, first, and fluconazole now.

Idiopathic anterior hypopituitarism: magnetic resonance imaging and clinical correlation.

We describe the anatomical abnormalities in the hypothalamic-pituitary region revealed by magnetic resonance imaging (MRI) in 10 patients, 8 men and 2 women, affected by idiopathic anterior hypopituitarism (IAH). In all cases contiguous sagittal and coronal T-1 weighted images were obtained. In 9 patients the high-intensity posterior lobe was missing, in almost all patients the pituitary stalk was thin and/or transected, and in 8 a bright T-1 nodule was detected at the infundibular apex, near the tuber cinereum, in the median eminence. None had diabetes insipidus. MRI proves to be very useful in understanding the etiopathogenesis of IAH.

[Mixed gonadal dysgenesis (MGD). Description of a case]. / Disgenesia gonadica mista (DGM). Descrizione di un caso.

The Authors report a case of mixed gonadal dysgenesis (DGM), with a mosaic karyotype consisting of two cell lines, one with 45 chromosomes and monosomic X (50%), the other with 46 chromosomes and one Y dicentric chromosome (50%). The patient presents a male phenotype, hypospadias (3rd degree), left cryptorchidism, hypotrophic right testis, short stature and a gonadal asymmetry.

[Changes in secretion of prolactin in obesity]. / Alterata secrezione della prolattina nella obesità.

The purpose of this study was to evaluate prolactin secretion in obesity. Basal level of serum prolactin and prolactin response after thyrotropin releasing hormone (TRH) were investigated in 20 obese patients and 20 healthy subjects well matched for age and sex. Obese patients had higher basal levels of serum prolactin than those of healthy subjects. Conversely, no significant difference in serum prolactin concentration was found at any time during TRH stimulating test. However obese patients showed incremental areas of serum prolactin slightly, but not significantly, lower compared to healthy subjects, probably because their basal levels were higher. In conclusion, the present study confirms that prolactin secretion is altered in obese patients. The discrepancy between basal levels and prolactin response during TRH stimulating test seems to indicate a deficiency in the dopaminergic inhibitor system.

[Skin disease in Basedow's disease]. / La dermopatia del morbo di Basedow.

Two cases of Graves' (Basedow) dermopathy are reported. In one case pretibial myxoedema was localized on the external surface of the legs down to insteps. In the second case a diffuse form involved both legs and was characterized by wrinkles and peau d'orange appearance at the ankles. In both cases a biopsy confirmed the diagnosis of Graves' dermopathy, showing diffuse areas of amorphus substance infiltrating the derma and fragmentation of collagen fibers. According to the literature, the skin lesions were associated with ophtalmopathy. Thyrostatic therapy affected ophtalmopathy in one of the patients, while pretibial myxoedema regressed in both. The pathogenesis of pretibial myxoedema is not completely clear yet, although dermopathy, along with ophtalmopathy and acropachy, is considered to be an extrathyroidal manifestation of Graves' disease related to bioassayble antibodies anti-TSH receptor. A class of dermopathy-associated antibodies (DAAb) has been identified. It seems to be a reliable biological marker for pretibial myxoedema since it is nearly absent in patients with ophtalmopathy and without dermopathy. Since DAAb does not stimulate human fibroblasts in culture, the role of DAAb in the development of Graves' dermopathy is still to be found.

The influence of reproductive and hormonal factors on thyroid cancer in women.

We conducted a study on 165 women with thyroid cancer and 214 hospital controls in order to investigate the role of reproductive and hormonal factors in the aetiology of thyroid cancer. Late age at menarche (Relative risk (RR) for menarche at greater than or equal to 14 vs less than or equal to 11 = 2.8), menstrual irregularity (RR = 1.7), late age at first birth (RR for first birth at greater than or equal to 28 vs less than or equal to 21 = 2.4) and at last birth (RR for last birth greater than or equal to 30 vs less than 30 = 2.2) significantly increased the risk of the development of thyroid cancer both in premenopausal and postmenopausal women. Parity was, in the present study rather inconsistently related to disease status whereas voluntary abortions and miscarriages were completely unrelated. A non significant increasing risk was observed with age at menopause older than 50, and with the use of oral contraceptives in premenopausal women. The mechanism of action of female hormones on the thyroid gland remains largely obscure, but the observation that age at first and, perhaps, subsequent pregnancies may be relevant points to an interplay of reproductive factors (and, possibly, their hormonal correlates) more complex than previously suggested.

Risk factors for thyroid cancer in northern Italy.

We conducted a hospital based case-control study of 245 cases of thyroid cancer (62 males and 183 females) and 411 controls in three areas of Northern Italy. Subjects with thyroid cancer more often had a history of benign thyroid nodules (18 cases versus 0 controls, lower 95% confidence limit = 7.84), goitre (RR = 5.61, 95% confidence interval (CI): 2.13-14.77) and residence in endemic goitre areas (RR for residence longer than 20 years = 2.29, 95% CI: 1.23-4.29). Heavy (greater than 1000 rads) irradiation of the neck was reported only by seven cases (lower 95% confidence limit: 2.45). Among 31 food items considered, a few showed direct association, including starchy foods and various sources of animal fats or proteins, whereas frequent consumption of other foods, including major sources of dietary iodine (such as fish, green vegetables and fruit) gave significant protection. When analysis was restricted to various subgroups of patients (ie, different histological types, sexes and major groups of hospital controls), it yielded similar results.