90 research outputs found

    Trade-off between offspring number and offspring size in the marine copepod Euterpina acutifrons at different food concentrations

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    collected females of the marine copepod Euterpina acutifrons monthly from November 1994 to January 1996 at a station located in Ria de Vigo (Spain). A trade-off between egg size and egg number was found. As food concentration measured as mean fluorescence in the water column diminished, mean number of eggs per sac carried per female decreased, whereas mean egg size increased. An experiment carried out with adult females cultured at different food concentrations confirmed the field results, and also showed that as egg size increased, there, was an increase in naupliar body length at hatching; nauplii developed faster to first copepodite stage, and net reproductive rate was higher. Therefore, the reproductive strategy of directing more energy toward offspring size rather than offspring number, at low food concentrations, clearly increases reproductive success.Postprin

    Rapporto tecnico sulla valutazione della biomassa ittioplanctonica mediante l'utilizzo del Multi Plankton Sampler (MPS)

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    Il piano di campionamento della campagna oceanografica BANSIC'14, condotta a bordo della N/O "URANIA" dal 22 Luglio al 9 Agosto 2014, lungo transetti sotto costa e a largo delle coste meridionali della Sicilia, ha avuto l’obiettivo generale dello studio delle relazioni tra le strutture oceanografiche a mesoscala (vortici verticali ed orizzontali, upwelling, etc.) e le strutture spaziali dei fenomeni biologici relativi ai primi anelli della catena trofica (zooplancton, distribuzione e abbondanza di larve di piccoli pelagici e grandi pelagici) (vedi Rapporto finale BANSIC 2014) per la stima dell’abbondanza dello stock riproduttore. E' una campagna di ricerca nell'ambito del WP3 del progetto SSD-Pesca, finanziato dal MIUR su fondi MISE, a supporto della pesca italiana nelle Regioni Obiettivo 1 e del progetto RITMARE (SP2_WP4_AZ2_UO04). Il campionamento ittioplanctonico è inserito anche nel piano di lavoro del progetto regionale MIPAF-FAO “MedSudMed” (“Assessment and Monitoring of the Fishery Resources and the Ecosystems in the Straits of Sicily”). Il campionamento dell’ittioplancton, durante questa campagna, oltre ai metodi tradizionali quali le reti di tipo Bongo, ha visto l'utilizzo del Multi Plankton Sampler (MPS) MultiNet. I campionatori ittioplanctonici hanno lo scopo di prelevare porzioni di mesozooplancton da un massimo di 100 m fino alla superficie, in quanto le uova di pesci pelagici possiedono una galleggiabilità tale che nonostante le turbolenze superficiali dell’acqua, un campionamento entro i primi metri restituisce un dato affidabile della distribuzione anche se alcune uova possono trovarsi a maggiore profondità (Ahlstrom, 1959). Il campionatore MPS consente, a differenza di altri strumenti, di prelevare la frazione di zooplancton d'interesse con diverse modalità di campionamento: orizzontale, verticale e obliquo e, allo stesso tempo, permette di campionare a differenti quote di profondità. Le informazioni così ottenute sono state utilizzate per valutare la variazione della biomassa ittioplanctonica, l'abbondanza e la composizione delle specie lungo gli strati della colonna d'acqua anche in relazione alle componenti oceanografiche. Grazie all'utilizzo di questo strumento è possibile validare e verificare alcune informazioni e acquisirne delle nuove sull’ecologia delle specie larvali e sul mesozooplancton, sul modo in cui queste si distribuiscono lungo la colonna d'acqua e sulle interazioni intra ed interspecifiche legate anche a fattori oceanografici. Ciò consente di ottenere maggiori informazioni e contribuire al miglioramento della comprensione della biologia e dell'ecologia delle specie rinvenute e, nel contempo, approfondire e migliorare le conoscenze sugli stadi di sviluppo di uova di specie ittiche che allo stadio embrionale sono ancora poco conosciuti

    Effect of nitric oxide on mitochondrial activity of human synovial cells

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    <p>Abstract</p> <p>Background</p> <p>Nitric oxide (NO) is a messenger implicated in the destruction and inflammation of joint tissues. Cartilage and synovial membrane from patients with rheumatoid arthritis (RA) and osteoarthritis (OA) have high levels of NO. NO is known to modulate various cellular pathways and, thus, inhibit the activity of the mitochondrial respiratory chain (MRC) of chondrocytes and induce the generation of reactive oxygen species (ROS) and cell death in multiple cell types. For these reasons, and because of the importance of the synovial membrane in development of OA pathology, we investigated the effects of NO on survival, mitochondrial function, and activity of fibroblastic human OA synovial cells.</p> <p>Methods</p> <p>Human OA synovia were obtained from eight patients undergoing hip joint replacement. Sodium nitroprusside (SNP) was used as a NO donor compound and cell viability was evaluated by MTT assays. Mitochondrial function was evaluated by analyzing the mitochondrial membrane potential (Δψm) with flow cytometry using the fluorofore DePsipher. ATP levels were measured by luminescence assays, and the activities of the respiratory chain complexes (complex I: NADH CoQ<sub>1 </sub>reductase, complex II: succinate dehydrogenase, complex III: ubiquinol-cytochrome c reductase, complex IV: cytochrome c oxidase) and citrate synthase (CS) were measured by enzymatic assay. Protein expression analyses were performed by western blot.</p> <p>Results</p> <p>SNP at a concentration of 0.5 mM induced cell death, shown by the MTT method at different time points. The percentages of viable cells at 24, 48 and 72 hours were 86.11 ± 4.9%, 74.31 ± 3.35%, and 43.88 ± 1.43%, respectively, compared to the basal level of 100% (*<it>p </it>< 0.05). SNP at 0.5 mM induced depolarization of the mitochondrial membrane at 12 hours with a decrease in the ratio of polarized cells (basal = 2.48 ± 0.28; SNP 0.5 mM = 1.57 ± 0.11; *<it>p </it>< 0.01). The time course analyses of treatment with SNP at 0.5 mM demonstrated that treatment reliably and significantly reduced intracellular ATP production (68.34 ± 14.3% vs. basal = 100% at 6 hours; *<it>p </it>< 0.05). The analysis of the MRC at 48 hours showed that SNP at 0.5 mM increased the activity of complexes I (basal = 36.47 ± 3.92 mol/min/mg protein, SNP 0.5 mM = 58.08 ± 6.46 mol/min/mg protein; *<it>p </it>< 0.05) and III (basal = 63.87 ± 6.93 mol/min/mg protein, SNP 0.5 mM = 109.15 ± 30.37 mol/min/mg protein; *<it>p </it>< 0.05) but reduced CS activity (basal = 105.06 ± 10.72 mol/min/mg protein, SNP at 0.5 mM = 66.88 ± 6.08 mol/min/mg protein.; *<it>p </it>< 0.05), indicating a decrease in mitochondrial mass. Finally, SNP regulated the expression of proteins related to the cellular cycle; the NO donor decreased bcl-2, mcl-1 and procaspase-3 protein expression.</p> <p>Conclusions</p> <p>This study suggests that NO reduces the survival of OA synoviocytes by regulating mitochondrial functionality, as well as the proteins controlling the cell cycle.</p

    Screening mutations in myosin binding protein C3 gene in a cohort of patients with Hypertrophic Cardiomyopathy

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    <p>Abstract</p> <p>Background</p> <p><it>MyBPC3 </it>mutations are amongst the most frequent causes of hypertrophic cardiomyopathy, however, its prevalence varies between populations. They have been associated with mild and late onset disease expression. Our objectives were to establish the prevalence of <it>MyBPC3 </it>mutations and determine their associated clinical characteristics in our patients.</p> <p>Methods</p> <p>Screening by Single Strand Conformation Polymorphisms (SSCP) and sequencing of the fragments with abnormal motility of the <it>MyBPC3 </it>gene in 130 unrelated consecutive HCM index cases. Genotype-Phenotype correlation studies were done in positive families.</p> <p>Results</p> <p>16 mutations were found in 20 index cases (15%): 5 novel [D75N, V471E, Q327fs, IVS6+5G>A (homozygous), and IVS11-9G>A] and 11 previously described [A216T, R495W, R502Q (2 families), E542Q (3 families), T957S, R1022P (2 families), E1179K, K504del, K600fs, P955fs and IVS29+5G>A]. Maximum wall thickness and age at time of diagnosis were similar to patients with <it>MYH7 </it>mutations [25(7) vs. 27(8), p = 0.16], [46(16) vs. 44(19), p = 0.9].</p> <p>Conclusions</p> <p>Mutations in <it>MyBPC3 </it>are present in 15% of our hypertrophic cardiomyopathy families. Severe hypertrophy and early expression are compatible with the presence of <it>MyBPC3 </it>mutations. The genetic diagnosis not only allows avoiding clinical follow up of non carriers but it opens new possibilities that includes: to take preventive clinical decisions in mutation carriers than have not developed the disease yet, the establishment of genotype-phenotype relationship, and to establish a genetic diagnosis routine in patients with familial HCM.</p

    NEXT-CRAB-0: A High Pressure Gaseous Xenon Time Projection Chamber with a Direct VUV Camera Based Readout

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    The search for neutrinoless double beta decay (0νββ0\nu\beta\beta) remains one of the most compelling experimental avenues for the discovery in the neutrino sector. Electroluminescent gas-phase time projection chambers are well suited to 0νββ0\nu\beta\beta searches due to their intrinsically precise energy resolution and topological event identification capabilities. Scalability to ton- and multi-ton masses requires readout of large-area electroluminescent regions with fine spatial resolution, low radiogenic backgrounds, and a scalable data acquisition system. This paper presents a detector prototype that records event topology in an electroluminescent xenon gas TPC via VUV image-intensified cameras. This enables an extendable readout of large tracking planes with commercial devices that reside almost entirely outside of the active medium.Following further development in intermediate scale demonstrators, this technique may represent a novel and enlargeable method for topological event imaging in 0νββ0\nu\beta\beta.Comment: 32 Pages, 22 figure

    Right drug, right patient, right time: aspiration or future promise for biologics in rheumatoid arthritis?

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    Individualising biologic disease-modifying anti-rheumatic drugs (bDMARDs) to maximise outcomes and deliver safe and cost-effective care is a key goal in the management of rheumatoid arthritis (RA). Investigation to identify predictive tools of bDMARD response is a highly active and prolific area of research. In addition to clinical phenotyping, cellular and molecular characterisation of synovial tissue and blood in patients with RA, using different technologies, can facilitate predictive testing. This narrative review will summarise the literature for the available bDMARD classes and focus on where progress has been made. We will also look ahead and consider the increasing use of ‘omics’ technologies, the potential they hold as well as the challenges, and what is needed in the future to fully realise our ambition of personalised bDMARD treatment

    A Compact Dication Source for Ba2+^{2+} Tagging and Heavy Metal Ion Sensor Development

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    We present a tunable metal ion beam that delivers controllable ion currents in the picoamp range for testing of dry-phase ion sensors. Ion beams are formed by sequential atomic evaporation and single or multiple electron impact ionization, followed by acceleration into a sensing region. Controllability of the ionic charge state is achieved through tuning of electrode potentials that influence the retention time in the ionization region. Barium, lead, and cobalt samples have been used to test the system, with ion currents identified and quantified using a quadrupole mass analyzer. Realization of a clean Ba2+\mathrm{Ba^{2+}} ion beam within a bench-top system represents an important technical advance toward the development and characterization of barium tagging systems for neutrinoless double beta decay searches in xenon gas. This system also provides a testbed for investigation of novel ion sensing methodologies for environmental assay applications, with dication beams of Pb2+^{2+} and Cd2+^{2+} also demonstrated for this purpose

    A Reinforcement Sensitivity Theory explanation of antisocial behaviour

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    A comprehensive explanation of antisocial behaviour (ASB) needs to focus on both individual differences in personality and life events as potentially predisposing factors. The current studies investigated the relative influence of both of these in males and females. We used the Reinforcement Sensitivity Theory (RST) of personality to investigate the extent to which dispositional approach and avoidance tendencies relate to ASB. In the first study, 287 participants reported their engagement in ASB and completed the RST Personality Questionnaire (RST-PQ). In the second study, a new sample of 282 participants completed the same measures as well as reporting the extent to which they had experienced life strains. Results from both studies showed a positive association between goal-drive persistence and ASB in males; while in females, a positive association was found between impulsivity and ASB. In Study 2, life strains explained further variance in ASB and this also show a gender differentiation: in males, there was a stronger relationship between financial strains and ASB while females showed an association between relational strains and ASB. Overall, results suggested that ASB is more pronounced in the male sample with an instrumental purpose while in the female sample personal life events are of more relevance

    Demographic, clinical and antibody characteristics of patients with digital ulcers in systemic sclerosis: data from the DUO Registry

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    OBJECTIVES: The Digital Ulcers Outcome (DUO) Registry was designed to describe the clinical and antibody characteristics, disease course and outcomes of patients with digital ulcers associated with systemic sclerosis (SSc). METHODS: The DUO Registry is a European, prospective, multicentre, observational, registry of SSc patients with ongoing digital ulcer disease, irrespective of treatment regimen. Data collected included demographics, SSc duration, SSc subset, internal organ manifestations, autoantibodies, previous and ongoing interventions and complications related to digital ulcers. RESULTS: Up to 19 November 2010 a total of 2439 patients had enrolled into the registry. Most were classified as either limited cutaneous SSc (lcSSc; 52.2%) or diffuse cutaneous SSc (dcSSc; 36.9%). Digital ulcers developed earlier in patients with dcSSc compared with lcSSc. Almost all patients (95.7%) tested positive for antinuclear antibodies, 45.2% for anti-scleroderma-70 and 43.6% for anticentromere antibodies (ACA). The first digital ulcer in the anti-scleroderma-70-positive patient cohort occurred approximately 5 years earlier than the ACA-positive patient group. CONCLUSIONS: This study provides data from a large cohort of SSc patients with a history of digital ulcers. The early occurrence and high frequency of digital ulcer complications are especially seen in patients with dcSSc and/or anti-scleroderma-70 antibodies
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