An information theory approach to stock market liquidity.

A novel methodology is introduced to dynamically analyze the complex scaling behavior of financial data across various investment horizons. This approach comprises two steps: (a) the application of a distribution-based method for the estimation of time-varying self-similarity matrices. These matrices consist of entries that represent the scaling parameters relating pairs of distributions of price changes constructed for different temporal scales (or investment horizons); (b) the utilization of information theory, specifically the Normalized Compression Distance, to quantify the relative complexity and ascertain the similarities between pairs of self-similarity matrices. Through this methodology, distinct patterns can be identified and they may delineate the levels and the composition of market liquidity. An application to the U.S. stock index S&P500 shows the effectiveness of the proposed methodology.

Contraception during Coronavirus-Covid 19 pandemia. Recommendations of the Board of the Italian Society of Contraception.

Purpose: The Italian Society of Contraception identified as one of its priorities the need to give recommendations on management of contraception during Coronavirus-Covid 19 pandemiaMaterials and methods: A concise communication was produced which summarises in an easy-to-read format suitable for clinicians the management of the different contraceptives mostly used. Information how to manage contraception in different conditions is presented.Results: Women may, in general, continue to use either intrauterine and or hormonal contraceptives. The use of condom should be added to any hormonal contraceptive, when the contraceptive efficacy is reduced or when women stop the contraceptive method.Conclusion: At the present time, during the Coronavirus-Covid 19 pandemia, no data contraindicate the use of intrauterine or hormonal contraceptives. Conversely the use of an appropriate contraception is advocate to prevent unintended pregnancies.

Alport's syndrome.

Alport's syndrome (AS, OMIM 301050) is a hereditary disorder characterized by progressive renal failure, hearing impairment and ocular changes. It is clinically and genetically heterogeneous and in its natural history, renal disease progresses from microscopic haematuria to proteinuria, and finally to progressive renal insufficiency. AS is caused by an inherited defect in a type IV collagen, a structural material, expressed in many tissues that is essential for the normal function of different parts of the body. In most of cases, about the 85%, Alport's syndrome is X-linked and is originated by mutations in the COL4A5 gene. In the remaining cases, it may be inherited in either an autosomal recessive, or rarely in an autosomal dominant manner. Mostly, the condition is caused by mutations in the COL4A3 or COL4A4 genes. Coexisting mutations in COL4A3, COL4A4, COL4A5 or COL4A6 were found to cause an Alport's syndrome phenotype with digenic inheritance. Diagnosis of the condition is based on family history, clinical signs, and specific procedures such as a kidney biopsy. The diagnosis can be confirmed by genetic testing. Treatment may include use of a hearing aid, hemodialysis, and peritoneal dialysis to treat those with end-stage renal failure, and, as the last step, kidney transplantation. Firstly described by Arthur C. Alport's, in 1927, over the years it has become a pathology of high scientific interest. At the moment, thanks to advances in diagnostic techniques, it is possible to make an early diagnosis avoiding irreversible damages and life -threatening complications.

Pharmacodynamics of combined estrogen-progestin oral contraceptives: 4. Effects on uterine and cervical epithelia.

Introduction: Steroid hormones are responsible for specific changes in the endometrium during the menstrual cycle, when they are sequentially secreted and, because of this, in the early days sequential combined oral contraceptive regimens were utilized. The same basic concept has been utilized with multi-phasic regimens, in order to produce endometrial pictures mimicking the normal cycle.Areas covered: The Endometrial effects of progestins and estrogens; combined monophasic high- (50 µg), medium- (30 µg), low- (20 µg), ultralow- (15 µg) estrogen content; sequential regimens; multiphasic combinations; treatment schedules.Cervical effects of combined high-dose and sequential combinations, including evidence for an increase in malignant lesions.Expert opinion: Overall, combined oral contraceptives (COCs) inhibit normal proliferative changes and the endometrium becomes thin, narrow, with widely spaced glands and pre-decidual changes in the stroma. During the first few cycles the progestin induces a coexistence of proliferative and secretory features; with time, the picture changes because the progestin induces a down-regulation of estrogen receptors, resulting in tortuous glands similar to those in the secretory phase, but characterized by a quiescent, atrophic glandular epithelium.In the cervical epithelium, under the influence of high-dose COCs, endocervical glands became hypersecretory and in some instances, distinctive type of atypical polypoid endocervical hyperplasia is found.

Phylogenetic characterization of the heterotrophic bacterial communities inhabiting a marine recirculating aquaculture system.

AIMS: The aim of the present work was to characterize the heterotrophic bacterial community of a marine recirculating aquaculture system (RAS). METHODS AND RESULTS: An experimental RAS was sampled for the rearing water (RW) and inside the biofilter. Samples were analysed for bacterial abundances, community structure and composition by using a combination of culture-dependent and -independent techniques. The most represented species detected among biofilter clones was Pseudomonas stutzeri, while Ruegeria spp. and Roseobacter spp. were more abundant among isolates. In comparison, the genera Roseobacter and Ruegeria were well represented in both the biofilter and the RW samples. A variety of possible bacterial pathogens (e.g. Vibrio spp., Erwinia spp. and Coxiella spp.) were also identified in this study. CONCLUSIONS: Results revealed that the bacterial community in the RW was quite different to that associated with the biofilter. Moreover, data obtained suggest that the whole bacterial community can be involved in maintaining an effective and a stable rearing environment (shelter effect). SIGNIFICANCE AND IMPACT OF THE STUDY: Improving the reliability and the sustainability of RAS depends on the correct management of the bacterial populations inside it. This study furnishes more accurate information on the bacterial populations and better clarifies the existing relationships between the bacterial flora in the RW and that associated with the biofilter.

Phase information and space filling curves in noisy motion estimation.

This correspondence presents a novel approach for translational motion estimation based on the phase of the Fourier transform. It exploits the equality between the averaging of a group of successive frames and the convolution of the reference one with an impulse train function. The use of suitable space filling curves allows to reduce the error in motion estimation making the proposed approach robust under noise. Experimental results show that the proposed approach outperforms available techniques in terms of objective (PSNR) and subjective quality with a lower computational effort.

Acquired activated protein C resistance in postmenopausal women is dependent on factor VIII:c levels.

Activated protein C (APC) resistance is an established risk factor for venous thromboembolism. In 5% to 10% of patients with venous thromboembolism, the APC resistance phenotype is observed in the absence of factor V Leiden mutation. Moreover, some physiologic and pathologic conditions are associated with an "acquired" APC resistance, not caused by the Leiden mutation, such as inflammatory diseases, pregnancy, or oral contraceptive therapy. Several studies have demonstrated the effect of menopause on the hemostatic system, but no data are available about APC resistance. We found a high prevalence of APC resistance in postmenopausal women, not associated with factor V Leiden mutation. The mechanism that underlies this acquired APC resistance may be related to the higher levels of factor VIII, which showed a strong inverse correlation with APC resistance, whereas no correlation was found between the normalized APC ratio, factor V levels, and protein S values. Higher levels of factor VIII correlated with a marker of coagulation activation, such as prothrombin fragments 1 plus 2. Therefore, to identify women receiving hormone replacement therapy who have a greater risk for deep venous thrombosis, the APC resistance coagulation test should be used instead of the genetic study.

Bone mineral metabolism in diet-induced amenorrhea.

Spinal bone density of 41 girls with diet-induced amenorrhea (DA) was compared with that of the density of 22 subjects with premature ovarian failure (POF) of comparable age. The Z score values, as well as the estradiol levels, were not significantly different in the two groups. The duration of amenorrhea was significantly correlated to bone mass density in the DA population, especially when considering subjects with amenorrhea that had lasted longer than 20 months. A similar correlation between weight loss and BMD was evident. Although estradiol concentrations did not seem to be correlated to the Z score, FT3 and cortisol values exhibited, respectively, a negative and a positive correlation with spinal density. Cortisol seemed to act precociously, whereas FT3 acted later than cortisol.

Estrogen replacement therapy in the management of osteopenia related to eating disorders.

The effect of hormone replacement therapy on the bone mineral content of hypoestrogenic subjects depends on the pathogenesis of the disease as well as on the dosage and route of administration. This is particularly true in hypoestrogenism related to eating disorders. We present a longitudinal study of 26 young women with diet-induced amenorrhea compared with a group of subjects with POF. The study protocol included the quantification of weight loss, the endocrine profile (follicle-stimulating hormone, luteinizing hormone, prolactin, E2, FT3, FT4, thyroid-stimulating hormone, and cortisol), the evaluation of markers of bone turnover (GLA, OSTK-PR, ALP, OHP, and DPYR), and spinal bone density by DEXA at observation and after weight recovery. No hormone replacement therapy was administered. Mean BMD and Z scores before and after recovery do not differ significantly; OHP and DPYR appear significantly higher during basal evaluation, whereas GLA and ALP do not. Data on the impact of oral contraceptive use on bone mineral density are controversial. We particularly discuss the question of long-term treatment with 20 micrograms ethinyl estradiol pills on peak bone mass acquisition during adolescence.

Changes in thromboxane A2 generation and plasma lipid pattern in pseudomenopause induced by gonadotropin releasing hormone (GnRH) analogue buserelin.

An increased risk of cardiovascular disease has been found in postmenopausal women in comparison to premenopausal women. The aim of this study was to investigate platelet function, blood clotting and plasma lipid levels in 12 women with a condition of hypoestrogenism, similar to the postmenopausal status induced by treatment with the GnRH analogue buserelin for uterine leiomyoma. Platelet aggregation in whole blood and platelet-rich plasma (PRP), serum thromboxane (TX) B2 production, fibrinopeptide A (FPA) plasma levels and plasma lipid pattern were measured before and after 13 weeks of buserelin treatment. No changes of platelet aggregability were found either in whole blood or PRP. Serum TXB2 generation increased significantly after 13 weeks of therapy (p less than 0.001). No signs of increased thrombin generation were found, as indicated by unchanged FPA plasma levels. Total cholesterol plasma levels were found increased after 13 weeks, LDL cholesterol levels showed a tendency to increase although not significantly. HDL cholesterol and triglyceride concentrations were unaffected. The changes of arachidonic acid metabolism and lipid pattern suggest that buserelin treatment may induce a condition of increased thrombotic risk even if the lack of enhanced thrombin generation and increased platelet aggregability indicates that no blood clotting activation occurs.

Effects of estrogen replacement therapy on thrombin generation.

The aim of this study was to investigate the hemostatic system in menopausal women before and after three months of treatment with transdermal estradiol (TTS 50, 50 micrograms/die, n = 13) or coniugated equine estrogen (CEE, 0.625 mg/die, n = 9) by evaluating : beta-thromboglobulin, platelet factor 4, factor VIIag, factor VIIc, fibrinopeptide A-FPA-, thrombin-antithrombin-TAT-complexes, antithrombin-AT-activity, protein C, plasma fibrinolytic activity (euglobulin clot lysis time), plasminogen and antiplasmin activity. FPA levels significantly increased during TTS 50 treatment (p < 0.001) while protein C showed a slight but significant decrease in both treatments (TTS 50 p < 0.001, CEE p < 0.05). TAT complexes and AT were found unaltered. Platelet function and fibrinolytic activity did not significantly change. A significant relationship between FPA and estradiol levels, which were significantly increased during. TTS 50 therapy, was found (r = 0.40, p < 0.05). These findings indicate that unopposed estradiol given by transdermal route induces a slight but significant blood clotting activation, which seems strictly related to its biological activity.

Salmon calcitonin plus intravaginal estriol: an effective treatment for the menopause.

OBJECTIVE: Intravaginal estriol (E3) effectively improves postmenopausal genito-urinary disturbances, without stimulating endometrial proliferation. The aim of the present study was to evaluate the effect of intravaginal estriol (E3) plus nasal spray salmon calcitonin (sCT), to improve neurovegetative symptoms and to prevent the decline of bone mineral density (BMD) of postmenopausal women. METHODS: Two hundred and fourteen (214) healthy postmenopausal women were treated for 12 months with: (1) E3 (0.5 mg every other day) + Ca (0.5 g/day); (2) E3 + Ca + sCT (50 IU x 2/day); (3) sCT + Ca; (4) Ca. Climacteric complaints, such as hot flushes and sweating, BMD at the distal 1/10 of the radius, analyzed by dual photon absorptiometry, urinary excretion of hydroxyproline and serum alkaline phosphatase were evaluated at baseline and every 6 months. At the same time, patient compliance and drug tolerability were evaluated. RESULTS: E3 but not sCT, improved hot flushes and sweating. E3 blunted but not completely counteracted the BMD decline observed in women treated with only Ca, and reduced urinary hydroxyproline excretion. sCT markedly increased BMD values and reduced both urinary hydroxyproline excretion and serum alkaline phosphatase. These effects were not potentiated by E3 coadministration. All treatments were well tolerated. CONCLUSIONS: Present data indicate that the combined administration of intravaginal E3 and sCT may represent an alternative therapeutic regimen for those postmenopausal women who do not accept or have contraindications to classical hormone replacement therapy.

Platelet and coagulation functions during triphasic oestrogen-progestogen treatment.

The purpose of this investigation was the longitudinal evaluation of the hemostatic system before and after 1, 3, and 6 months of treatment with a triphasic oestrogen-progestogen combination. No changes of circulating platelet aggregates, as an index of in vivo platelet aggregability, and of megathrombocytes, an indirect evaluation of accelerated thrombocytopoiesis, were observed. A very slight, but significant, increase of Fibrinopeptide A (FPA), a reliable index of thrombin formation, was found only after 1 month of treatment; after 3 and 6 months, the increase of FPA was not homogeneous and not significant. Antithrombin III activity (AT III) showed no modifications after the first month; after 3 months AT III increased to a small extent, and after 6 months it was similar to basal values. Our findings indicate that the triphasic combination does not modify platelet functions and induces a low-degree activation of coagulation counteracted by an increased activity of the physiological inhibitors of blood clotting.

Marine fungi in Terra Nova Bay (Ross Sea, Antarctica).

The occurrence of lignicolous marine fungi in Antarctic marine water far from the coast is reported. Thirty-six wooden baits (beech and poplar), hung in a metallic structure were immersed in Penguin Bay (Adelie Cove) at a depth of 50 m for a year. Fourteen species belonging to Deuteromycotina and six Ascomycotina were observed on the baits examined in Italy. Phoma sp., Trichocladium achrasporum, Trichocladium constrictum and Trichocladium lignincola were the predominant species. Phoma sp., the first species, are not typically marine, but rather of terrestrial origin. Penguin dung proximity can explain this occurrence.

Heterotrophic bacteria in the Ross Sea (Terra Nova Bay, Antarctica).

Microbial research on temporal variation of bacterial densities was carried out on seawater samples collected from two field stations at different depths during the Antarctic summer (oceanographic campaign 1989/1990). Bacterial densities evaluated on Marine Agar 2216 (Difco) and on TCBS Agar (Difco) after incubation at +4 degrees C for 21 days respectively ranged from 0 to 7.9 x 10(2) CFU/ml for heterotrophic bacteria and from 0 to 5.7 x 10(2) CFU/100ml for "presumptive vibrios". During the period of observation, Vibrio densities showed a higher variability than those of total heterotrophic bacteria. A high percentage of gelatinolytic and chitinolytic vibrios was observed. The qualitative composition of heterotrophic bacterial communities was studied on 38 morphological and biochemical characteristics of 152 strains isolated from the stations. The data were subsequently used to determine the structure and metabolic potentialities of bacterial communities in the two sites. Almost all the heterotrophic, psychrotrophic isolates were non fermentative Gram-negative rods, belonging to the genera Pseudomonas/Alcaligenes, Flavobacterium/Cytophaga. The bacterial communities in the two coastal habitats investigated were clearly different.

Psychrotrophic bacteria from a coastal station in the Ross sea (Terra Nova Bay, Antarctica).

Seawater samples were collected from a fixed, coastal station in the Terra Nova Bay at different depths during the Xth Oceanographic Cruise in the 1994-95 Antarctic summer. Picoplanktonic abundance, estimated by direct counts in epifluorescence microscopy, ranged from 2.2 x 10(7) to 1.6 x 10(8) cells.l-1. The heterotrophic bacterial densities, evaluated on Marine Agar 2216 (Difco) after incubation at +4 degrees C for 21 days, ranged from 2 x 10(3) to 4.5 x 10(6) CFU.l-1. The qualitative composition of the heterotrophic bacterial community was studied on 64 morphological and biochemical characters of the 125 strains isolated. Heterotrophic, psychrotrophic isolates were tentatively identified at genus level as Pseudomonas, Vibrio, Acinetobacter, and Flavobacterium/Cytophaga. In order to compare the characteristics of the isolates with those previously studied during 1989/90, the synthetical indices of the structure and the metabolic potentiality of the heterotrophic bacterial community were processed. Results showed that the bacterial community was metabolically more active and more homogenous than that previously studied.

Structural differences of the microbial community in two sites of the Terra Nova Bay (Ross Sea, Antarctica): a statistical analysis.

The microbial community structure was investigated in a one month survey at two sampling stations located in the Terra Nova Bay (Antarctica). The microbial assemblage was studied by direct counts with epifluorescent microscopy (picoplankton and picophytoplankton), fractionated adenosine-triphosphate, lipopolysaccarides and bacterial growth on cultural medium. The results underwent the Spearman rank correlation and the principal component analysis together with other environmental parameters (temperature, salinity, nutrient salts and chlorophyll a) with the aim of revealing differences in the microbial community structure between the in-shore and off-shore sites.

Characterization of antarctic hydrocarbon-degrading bacteria capable of producing bioemulsifiers.

During screening for biosurfactant-producing, n-alkane-degrading marine bacteria, two heterotrophic bacterial strains were isolated from enriched mixed cultures, obtained from Terra Nova Bay (Ross sea, Antarctica) by using aliphatic and artomatic hydrocarbons as the principal carbon source. These gram-positive, aerobic, cocci-shaped bacteria use a various number of organic compounds, including aliphatic hydrocarbons, volatile fatty acids, and biphenyl. During cultivation on n-alkanes as sole source of carbon and energy, all strains produced both an extracellular and cell-bound surface-active mixture of trehalose lipids which reduced the surface tension of water from 72 mN/m to 32mN/m. This class of glycolipids was found to be produced only by marine rhodococci. The 16S-rRNA gene sequence analysis showed that both strains are members of the G + C rich gram-positive group of the phylum Proteobacteria and was found to be almost identical to that of Rhodococcus fascians DSM 20669. The potential of these strains for in situ bioremediation of contaminated cold marine environment is discussed in the present study.

Variability of some microbial parameters in relation to the hydrological features of the water column in the Eolian Basin (Southern Tyrrhenian Sea).

During the EOCUMM '94 cruise, 15 stations located in the Eolian Islands area (Southern Tyrrhenian Sea) were sampled to analyse the distributions of the total bacterioplankton densities and the heterotrophic viable bacteria counts on Marine Agar 2216. According to the TS (temperature-salinity) diagrams, obtained by processing the CTD (conductivity-temperature-depth) vertical profiles, the sampled stations were grouped in "hydrological clusters". The bacteriological variables, together with the chlorophyll a and the particulate organic carbon measures obtained during the same cruise were used to compare the stations of the same and different clusters. The results indicated that variabilities of the analysed microbial parameters were not obviously related to the hydrographic features of the sampling stations. This work is an attempt to verify the possibility of using microbial parameters to characterize the structure of the water column.

Prevalence of hemostatic disorders in adolescents with abnormal uterine bleeding.

STUDY OBJECTIVE: To evaluate the incidence of hemostatic disorders in a population of adolescents with various patterns of abnormal uterine bleeding (AUB). DESIGN: Retrospective observational study. SETTING: University hospital. PARTICIPANTS: One hundred thirteen adolescents with AUB; mean age at menarche and mean age at the onset of symptoms 12 ± 1.2 years and 13.5 ± 2.8 years, respectively. MAIN OUTCOME MEASURES: Data on menstrual history, bleeding symptoms, co-existing medical conditions, and medical therapies were assessed. All patients were screened for hemostatic disorders with laboratory testing. The incidence of the disorders was calculated. Subjects were further divided in 2 groups based on whether the AUB started in the first 2 years from menarche (group 1) or later (group 2). A statistical analysis was performed using a chi-square test to compare incidence of hemostatic disorders between the groups. RESULTS: One hundred thirteen adolescents with AUB were identified. Overall, 54 (47.8%) patients had some underlying hemostatic disorder, of which a platelet dysfunction was the most common (17.7%). Von Willebrand disease was detected in 13.3% of cases and a deficiency of a coagulation factor in 12.4%. In 7.1% of patients an isolated increase of bleeding time was observed. When divided in 2 groups, 44.2% of patients in group 1 and 59.2% in group 2 had a coagulation disorders, with no statistically significant difference between the 2 groups (P = .17). CONCLUSION: AUB in adolescents is frequently associated with an underlying disorder of hemostasis, most commonly a platelet function disorder. The results highlight the importance of screening for coagulation disorders in adolescents with AUB, independently from the gynecologic age at onset.