Factorisation theorems for generalised power series

Fields of generalised power series (or Hahn fields), with coefficients in a field and exponents in a divisible ordered abelian group, are a fundamental tool in the study of valued and ordered fields and asymptotic expansions. The subring of the series with non-positive exponents appear naturally when discussing exponentiation, as done in transseries, or integer parts. A notable example is the ring of omnific integers inside the field of Conway's surreal numbers. In general, the elements of such subrings do not have factorisations into irreducibles. In the context of omnific integers, Conway conjectured in 1976 that certain series are irreducible (proved by Berarducci in 2000), and that any two factorisations of a given series share a common refinement. Here we prove a factorisation theorem for the ring of series with non-positive real exponents: every series is shown to be a product of irreducible series with infinite support and a factor with finite support which is unique up to constants. From this, we shall deduce a general factorisation theorem for series with exponents in an arbitrary divisible ordered abelian group, including omnific integers as a special case. We also obtain new irreducibility and primality criteria. To obtain the result, we prove that a new ordinal-valued function, which we call degree, is a valuation on the ring of generalised power series with real exponents, and we formulate some structure results on the associated RV monoid

Exponential fields and Conway's omega-map

Inspired by Conway's surreal numbers, we study real closed fields whose value group is isomorphic to the additive reduct of the field. We call such fields omega-fields and we prove that any omega-field of bounded Hahn series with real coefficients admits an exponential function making it into a model of the theory of the real exponential field. We also consider relative versions with more general coefficient fields

L'Italia come modello per l'Europa e per il mondo nelle politiche sanitarie per il trattamento dell'epatite cronica da HCV

The World Health Organization foresees the elimination of HCV infection by 2030. In light of this and the curre nt, nearly worldwide, restriction in direct-acting agents (DAA) accessibility due to their high price, we aimed to evaluate the cost-effectiveness of two alternative DAA treatment policies: Policy 1 (universal): treat all patients, regardless of the fibrosis stage; Policy 2 (prioritized): treat only priori tized patients and delay treatment of the remaining patients until reaching stage F3. T he model was based on patient’s data from the PITER cohort. We demonstrated that extending HC V treatment of patients in any fibrosis stage improves health outcomes and is cost-effective

Evidence of poor welfare in goats with external abscesses

Introduction - In addition to lameness and mastitis, the presence of abscesses is one of the most common health problems in small ruminants. Abscesses can have a negative impact on famers' income. The presence of external abscesses has been suggested has a possible animal-based indicator for on-farm welfare assessment, but further studies are required in order to confirm the relationship of this indicator with animal welfare. Aim - The aim of this research was to verify whether the presence of external abscesses in dairy goats is associated with behavioural changes and general poor health conditions, to support its inclusion in on-farm welfare assessment protocols. Materials and methods - We assessed the presence of abscesses in 35 lactating Saanen goats. Animals were submitted to veterinary inspection to record the number and location of external abscess, Body Condition Score, rectal temperature, heart rate, respiratory rate, and conjunctival mucosae colour. Rumen and lung auscultation were also performed and blood samples were collected for analysis of haematocrit, haemoglobin concentration, leukocyte count, and total protein concentration. Behavioural observations (scan sampling every 2 minutes for 3 h/d for 3 d; total observation time = 9 h) were carried out on 8 goats with abscesses and 8 goats without abscesses. Results and discussion - Goats with abscesses (n = 12) showed a poorer body condition (expressed by BCS; P = 0.05) and a higher heart rate (P< 0.05), white blood cell count (P< 0.01) and total protein concentration (P< 0.001); one goat with abscesses had ruminal atony. Goats with abscesses also showed a significantly lower overall proportion of time spent feeding (P< 0.001) and a higher overall proportion of time spent chewing (P< 0.001). Conclusions - Our results suggest that the presence of external abscesses may be associated to an altered health condition of the animals and to behavioural changes, and can therefore be used as an animal-based indicator in welfare assessment protocols for dairy goats, although further research is required to confirm these preliminary results

The Unusual Lipid A Structure and Immunoinhibitory Activity of LPS from Marine Bacteria Echinicola pacifica KMM 6172T and Echinicola vietnamensis KMM 6221T

Gram-negative bacteria experiencing marine habitats are constantly exposed to stressful conditions dictating their survival and proliferation. In response to these selective pressures, marine microorganisms adapt their membrane system to ensure protection and dynamicity in order to face the highly mutable sea environments. As an integral part of the Gram-negative outer membrane, structural modifications are commonly observed in the lipopolysaccharide (LPS) molecule; these mainly involve its glycolipid portion, i.e., the lipid A, mostly with regard to fatty acid content, to counterbalance the alterations caused by chemical and physical agents. As a consequence, unusual structural chemical features are frequently encountered in the lipid A of marine bacteria. By a combination of data attained from chemical, MALDI-TOF mass spectrometry (MS), and MS/MS analyses, here, we describe the structural characterization of the lipid A isolated from two marine bacteria of the Echinicola genus, i.e., E. pacifica KMM 6172T and E. vietnamensis KMM 6221T. This study showed for both strains a complex blend of mono-phosphorylated tri- and tetra-acylated lipid A species carrying an additional sugar moiety, a d-galacturonic acid, on the glucosamine backbone. The unusual chemical structures are reflected in a molecule that only scantly activates the immune response upon its binding to the LPS innate immunity receptor, the TLR4-MD-2 complex. Strikingly, both LPS potently inhibited the toxic effects of proinflammatory Salmonella LPS on human TLR4/MD-2

The unusual lipid a structure and immunoinhibitory activity of LPS from marine bacteria echinicola pacifica KMM 6172T and echinicola Vietnamensis KMM 6221T

Gram-negative bacteria experiencing marine habitats are constantly exposed to stressful conditions dictating their survival and proliferation. In response to these selective pressures, marine microorganisms adapt their membrane system to ensure protection and dynamicity in order to face the highly mutable sea environments. As an integral part of the Gram-negative outer membrane, structural modifications are commonly observed in the lipopolysaccharide (LPS) molecule; these mainly involve its glycolipid portion, i.e., the lipid A, mostly with regard to fatty acid content, to counterbalance the alterations caused by chemical and physical agents. As a consequence, unusual structural chemical features are frequently encountered in the lipid A of marine bacteria. By a combination of data attained from chemical, MALDI-TOF mass spectrometry (MS), and MS/MS analyses, here, we describe the structural characterization of the lipid A isolated from two marine bacteria of the Echinicola genus, i.e., E. pacifica KMM 6172T and E. vietnamensis KMM 6221T. This study showed for both strains a complex blend of mono-phosphorylated tri-and tetra-acylated lipid A species carrying an additional sugar moiety, a D-galacturonic acid, on the glucosamine backbone. The unusual chemical structures are reflected in a molecule that only scantly activates the immune response upon its binding to the LPS innate immunity receptor, the TLR4-MD-2 complex. Strikingly, both LPS potently inhibited the toxic effects of proinflammatory Salmonella LPS on human TLR4/MD-2