412 research outputs found
Spreads of and ovoids of polar spaces
To any spread S of PG(3,q) corresponds a family of locally
hermitian ovoids of the Hermitian surface H(3, q^2), and
conversely;
if in addition S is a semifield spread, then each
associated ovoid is a translation ovoid, and conversely.
In this paper we calculate the translation group of the locally
hermitian ovoids of H(3,q^2) arising from a given semifield
spread,
and we characterize the p-semiclassical ovoid constructed by Cossidente, Ebert, Marino and Siciliano as the only translation ovoid of H(3,q^2)
whose
translation group is abelian.
If S is a spread of PG(3,q) and O(S) is one of the
associated ovoids of H(3,q^2),
then using the duality between
H(3,q^2) and Q^-(5, q) , another spread of PG(3,q) , say
S_1, can be constructed.
On the other hand, using the
Barlotti-Cofman representation of H(3,q^2), one more spread of a
3-dimensional projective space,
say S_2, arises from the
ovoid O(S). Lunardon has posed some questions on the
relations among S, S_1 and S_2;
here we prove that the
three spreads are always isomorphic
Maximum scattered linear sets and MRD-codes
The rank of a scattered -linear set of , rn even, is at most rn / 2 as it was proved by Blokhuis and Lavrauw. Existence results and explicit constructions were given for infinitely many values of r, n, q (rn even) for scattered -linear sets of rank rn / 2. In this paper, we prove that the bound rn / 2 is sharp also in the remaining open cases. Recently Sheekey proved that scattered -linear sets of of maximum rank n yield -linear MRD-codes with dimension 2n and minimum distance . We generalize this result and show that scattered -linear sets of of maximum rank rn / 2 yield -linear MRD-codes with dimension rn and minimum distance n - 1
Body length rather than routine metabolic rate and body condition correlates with activity and risk-taking in juvenile zebrafish Danio rerio
In this study, the following hypotheses were explored using zebrafish Danio rerio: (1) individuals from the same cohort differ consistently in activity and risk-taking and (2) variation in activity and risk-taking is linked to individual differences in metabolic rate, body length and body condition. To examine these hypotheses, juvenile D. rerio were tested for routine metabolic rate and subsequently exposed to an open field test. Strong evidence was found for consistent among-individual differences in activity and risk-taking, which were overall negatively correlated with body length, i.e. larger D. rerio were found to be less active in a potentially dangerous open field and a similar trend was found with respect to a more direct measure of their risk-taking tendency. In contrast, routine metabolic rate and body condition were uncorrelated with both activity and risk-taking of juvenile D. rerio. These findings suggest that body length is associated with risk-related behaviours in juvenile D. rerio for which larger, rather than smaller, individuals may have a higher risk of predation, while the role for routine metabolic rate is relatively limited or non-existent, at least under the conditions of the present study
Temporal repeatability of behaviour in a lizard: implications for behavioural syndrome studies
It is well established that, across taxa, individuals within populations exhibit consistent differences in their behaviour across time and/or contexts. Further, the functional coupling of traits may result in the formation of a behavioural syndrome. Despite extensive evidence on the existence of consistent among-individual differences in behaviour and behavioural syndromes in the animal realm, these findings are predominately based upon short-term assessments, leading to questions regarding their stability over longer periods. Understanding if these estimates are temporally stable would allow predictions of individual behaviour to be made using short-term repeated measures. Here, we used 57 adult male delicate skinks (Lampropholis delicata) to evaluate the stability of behavioural variation observed both among (animal personality and behavioural plasticity) and within individuals (behavioural predictability), as well as behavioural syndromes, across short (four weeks) and long (five months) timeframes. To do so, we repeatedly assayed activity, exploration, and boldness five times per each individual. Overall, our study revealed complex patterns of behavioural variation and trait (co)variation over time. Activity was always repeatable across time intervals, whereas behavioural differences among individuals in exploration and boldness were not consistent. Yet a behavioural syndrome between activity and exploration was detected at both shorter and longer temporal scales, suggesting that syndrome structure in these traits does not vary as a function of time. Our findings indicate that, at least for some traits (e.g. activity) and studies, short-term measures may be adequate in serving as a proxy for long-term variation in individual behaviour, and to reveal the existence of behavioural syndromes at the population level
e-Health solution for home patient telemonitoring in early post-acute TIA/Minor stroke during COVID-19 pandemic
Background: When it comes to critical early post-acute TIA/stroke phase, there is a lack of a comprehensive multi-parametric telemonitoring system. The COVID-19 emergency, its related global mobility restrictions and fear of hospitalization further highlighted the need of a comprehensive solution. Objective: We aimed to design and test a pragmatic e-Health system based on multiparametric telemonitoring to support of TIA/stroke patients in sub-acute phase during the COVID-19 pandemic. Methods: We proposed a telemonitoring system and protocol for TIA/minor stroke patients during COVID-19 pandemic for patients at risk of stroke recurrence. This system involves the use of portable devices for BP/HR/SpO2/temperature sensing, panic-button, gateway, and a dedicated ICT platform. The protocol is a 14-day multiparametric telemonitoring, therapy, and emergency intervention based on vital sign alteration notifications. We conducted a proof-of-concept validation test on 8 TIA/minor stroke patients in the early post-acute phase (< 14 days from ischemic event). Results: The proposed solution allowed to promptly and remotely identify vital sign alterations at home during the early post-acute phase, allowing therapy and behavioral intervention adjustments. Also, we observed a significant improvement of quality of life, as well as a significant reduction of anxiety and depression status. TUQ showed ease of use, good interface quality and high user satisfaction of the proposed solution. The 3-month follow-up showed total adherence of prescribed therapy and no stroke/TIA recurrence or other emergency department admissions. Conclusion: The proposed e-Health solution and telemonitoring protocol may be highly useful for early post-acute remote patient management, thus supporting constant monitoring and patient adherence to the treatment pathway, especially during the COVID-19 emergency
A characterization of linearized polynomials with maximum kernel
We provide sufficient and necessary conditions for the coefficients of a q-polynomial f over Fqn which ensure that the number of distinct roots of f in Fqn equals the degree of f. We say that these polynomials have maximum kernel. As an application we study in detail q-polynomials of degree qnâ2 over Fqn which have maximum kernel and for nâ€6 we list all q-polynomials with maximum kernel. We also obtain information on the splitting field of an arbitrary q-polynomial. Analogous results are proved for qs-polynomials as well, where gcdâĄ(s,n)=1
The best of respiratory infections from the 2015 European respiratory society international congress
The breadth and quality of scientific presentations on clinical and translational research into respiratory infections at the 2015 European Respiratory Society (ERS) International Congress in Amsterdam, the Netherlands, establishes this area as one of the leadings fields in pulmonology. The host\u2013pathogen relationship in chronic obstructive pulmonary disease, and the impact of comorbidities and chronic treatment on clinical outcomes in patients with pneumonia were studied. Various communications were dedicated to bronchiectasis and, in particular, to different prognostic and clinical aspects of this disease, including chronic infection with Pseudomonas and inhaled antibiotic therapy. Recent data from the World Health Organization showed that Europe has the highest number of multidrug-resistant tuberculosis cases and the poorest countries have the least access to suitable treatments. Latent tuberculosis and different screening programmes were also discussed with particular attention to risk factors such as HIV infection and diabetes. Several biomarkers were proposed to distinguish between active tuberculosis and latent infection. Major treatment trials were discussed (REMOX, RIFQUIN and STREAM). The possibility of once-weekly treatment in the continuation phase (RIAQUIN) was especially exciting. The continuing rise of Mycobacterium abscessus as a significant pathogen was noted. This article reviews some of the best contributions from the Respiratory Infections Assembly to the 2015 ERS International Congress
Addition of hyaluronic acid improves tlerance to 7% hypertonic saline solution in bronchiectasis patients.
Background: The excessive retention of sputum in the airways, leading to pulmonary infections, is a common consequence of bronchiectasis. Although inhalation of 7% hypertonic saline (HS) has proven an effective method to help remove the mucus, many patients are intolerant of this treatment. The addition of 0.1% hyaluronic acid to HS (HS+HA) could increase tolerance to HS in these patients. The main objective of this study was to evaluate the tolerability of HS+HA in bronchiectasis patients who are intolerant to HS. Methods: This prospective, observational, open-label study analysed the outcomes of two groups of bronchiectasis patients previously scheduled to start HS therapy. Patients were assessed for tolerance to HS by a questionnaire, spirometry and clinical evaluation. Patients who were intolerant were evaluated for tolerance to HS+HA approximately one week later. All patients were evaluated for their tolerance to HS or HS+HA 4 weeks after the start of their treatment. Patients were also assessed with quality-of-life and adherence questionnaires, and all adverse events were registered. Results: A total of 137 bronchiectasis patients were enrolled in the study (age = 63.0 ± 14.7 years; 63.5% women). Of these, 92 patients (67.1%) were tolerant and 45 patients (32.9%) were intolerant to HS. Of the 45 patients intolerant to HS, 31 patients (68.9%) were tolerant and 14 patients (31.1%) intolerant to HS+HA. Of these 31 tolerant patients, 26 (83.9%) could complete the 4-week treatment with HS+HA. Conclusions: Two-thirds of bronchiectasis patients that presented intolerance to inhaled HS alone are tolerant to inhaled HS+HA, suggesting that HA improves tolerance to HS therapy
Somatotypes trajectories during adulthood and their association with COPD phenotypes
Rationale: Chronic obstructive pulmonary disease (COPD) comprises distinct phenotypes, all characterised by airflow limitation.
Objectives: We hypothesised that somatotype changes - as a surrogate of adiposity - from early adulthood follow different trajectories to reach distinct phenotypes.
Methods: Using the validated Stunkard''s Pictogram, 356 COPD patients chose the somatotype that best reflects their current body build and those at ages 18, 30, 40 and 50 years. An unbiased group-based trajectory modelling was used to determine somatotype trajectories. We then compared the current COPD-related clinical and phenotypic characteristics of subjects belonging to each trajectory.
Measurements and main results: At 18 years of age, 88% of the participants described having a lean or medium somatotype (estimated body mass index (BMI) between 19 and 23 kg.m(-2)) while the other 12% a heavier somatotype (estimated BMI between 25 and 27 kg.m(-2)). From age 18 onwards, five distinct trajectories were observed. Four of them demonstrating a continuous increase in adiposity throughout adulthood with the exception of one, where the initial increase was followed by loss of adiposity after age 40. Patients with this trajectory were primarily females with low BMI and D-LCO (diffusing capacity of the lung for carbon monoxide). A persistently lean trajectory was seen in 14% of the cohort. This group had significantly lower forced expiratory volume in 1 s (FEV1), D-LCO, more emphysema and a worse BODE (BMI, airflow obstruction, dyspnoea and exercise capacity) score thus resembling the multiple organ loss of tissue (MOLT) phenotype.
Conclusions: COPD patients have distinct somatotype trajectories throughout adulthood. Those with the MOLT phenotype maintain a lean trajectory throughout life. Smoking subjects with this lean phenotype in early adulthood deserve particular attention as they seem to develop more severe COPD
B cellâadaptive immune profile in emphysema-predominant chronic obstructive pulmonary disease
Cigarette smoke, the major risk factor for COPD in developed countries, causes pulmonary inflammation that persists long after smoking cessation, suggesting self-perpetuating adaptive immune responses similar to those that occur in autoimmune diseases. Increases in the number and size of B cellârich lymphoid follicles (LFs) have been shown in patients in severe stages of COPD (4), and increased B-cell products (autoantibodies) have been observed in the blood and lungs of patients with COPD (5, 6). Oligoclonal rearrangement of the immunoglobulin genes has been observed in B cells isolated from COPD LFs, suggesting that a specific antigenic stimulation drives B-cell proliferation. Consistently, we have shown that in the COPD lung, there is an overexpression of BAFF (B-cell activation factor of the TNF family), which is a key regulator of B-cell homeostasis in several autoimmune diseases (7) and is involved in the growth of LFs in COPD. However, a network analysis of lung transcriptomics showed that a prominent B-cell molecular signature characterized emphysema preferentially but was absent in AD independently of the degree of airflow limitation (8). In the current study, we investigated the correlation between B-cell responses in lung tissue from patients with COPD and healthy smokers, and the extent of emphysema versus airflow limitation
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