A Formalism for Scattering of Complex Composite Structures. 2 Distributed Reference Points

Recently we developed a formalism for the scattering from linear and acyclic branched structures build of mutually non-interacting sub-units.{[}C. Svaneborg and J. S. Pedersen, J. Chem. Phys. 136, 104105 (2012){]} We assumed each sub-unit has reference points associated with it. These are well defined positions where sub-units can be linked together. In the present paper, we generalize the formalism to the case where each reference point can represent a distribution of potential link positions. We also present a generalized diagrammatic representation of the formalism. Scattering expressions required to model rods, polymers, loops, flat circular disks, rigid spheres and cylinders are derived. and we use them to illustrate the formalism by deriving the generic scattering expression for micelles and bottle brush structures and show how the scattering is affected by different choices of potential link positions.Comment: Paper no. 2 of a serie

Combined local and systemic immunization is essential for durable T-cell mediated heterosubtypic immunity against influenza A virus

The threat from unpredictable influenza virus pandemics necessitates the development of a new type of influenza vaccine. Since the internal proteins are highly conserved, induction of T cells targeting these antigens may provide the solution. Indeed, adenoviral (Ad) vectors expressing flu nucleoprotein have previously been found to induce short-term protection in mice. In this study we confirm that systemic (subcutaneous (s.c.) immunization rapidly induced heterosubtypic protection predominantly mediated by CD8 T cells, but within three months clinical protection completely disappeared. Local (intranasal (i.n.)) immunization elicited delayed, but more lasting protection despite relatively inefficient immunization. However, by far, the most robust protection was induced by simultaneous, combined (i.n. + s.c.) vaccination, and, notably, in this case clinical protection lasted at least 8 months without showing any evidence of fading. Interestingly, the superior ability of the latter group to resist reinfection correlated with a higher number of antigen-specific CD8 T cells in the spleen. Thus, detailed analysis of the underlying CD8 T cell responses highlights the importance of T cells already positioned in the lungs prior to challenge, but at the same time underscores an important back-up role for circulating antigen-specific cells with the capacity to expand and infiltrate the infected lungs

No Evidence for Pre-Copulatory Sexual Selection on Sperm Length in a Passerine Bird

There is growing evidence that post-copulatory sexual selection, mediated by sperm competition, influences the evolution of sperm phenotypes. Evidence for pre-copulatory sexual selection effects on sperm traits, on the other hand, is rather scarce. A recent paper on the pied flycatcher, Ficedula hypoleuca, reported phenotypic associations between sperm length and two sexually selected male traits, i.e. plumage colour and arrival date, thus invoking pre-copulatory sexual selection for longer sperm. We were unable to replicate these associations with a larger data set from the same and two additional study populations; sperm length was not significantly related to either male plumage colour or arrival date. Furthermore, there was no significant difference in sperm length between populations despite marked differences in male plumage colour. We also found some evidence against the previously held assumption of longer sperm being qualitatively superior; longer sperm swam at the same speed as shorter sperm, but were less able to maintain speed over time. We argue that both empirical evidence and theoretical considerations suggest that the evolution of sperm morphology is not primarily associated with pre-copulatory sexual selection on male secondary sexual traits in this or other passerine bird species. The relatively large between-male variation in sperm length in this species is probably due to relaxed post-copulatory sexual selection

PB1 as a potential target for increasing the breadth of T-cell mediated immunity to Influenza A

Recently, we showed that combined intranasal and subcutaneous immunization with a non-replicating adenoviral vector expressing NP of influenza A, strain PR8, induced long-standing protection against a range of influenza A viruses. However, H-2(b) mice challenged with an influenza A strain mutated in the dominant NP(366) epitope were not efficiently protected. To address this problem, we envision the use of a cocktail of adenovectors targeting different internal proteins of influenza A virus. Consequently, we investigated the possibility of using PB1 as a target for an adenovector-based vaccine against influenza A. Our results showed that PB1 is not as immunogenic as the NP protein. However, by tethering PB1 to the murine invariant chain we were able to circumvent this problem and raise quite high numbers of PB1-specific CD8(+) T cells in the circulation. Nevertheless, mice immunized against PB1 were not as efficiently protected against influenza A challenge as similarly NP-vaccinated animals. The reason for this is not a difference in the quality of the primed cells, nor in functional avidity. However, under similar conditions of immunization fewer PB1-specific cells were recruited to the airways, and surface expression of the dominant PB1 peptide, PB1(703), was less stable than in the case of NP(366)

Translation Representations and Scattering By Two Intervals

Studying unitary one-parameter groups in Hilbert space (U(t),H), we show that a model for obstacle scattering can be built, up to unitary equivalence, with the use of translation representations for L2-functions in the complement of two finite and disjoint intervals. The model encompasses a family of systems (U (t), H). For each, we obtain a detailed spectral representation, and we compute the scattering operator, and scattering matrix. We illustrate our results in the Lax-Phillips model where (U (t), H) represents an acoustic wave equation in an exterior domain; and in quantum tunneling for dynamics of quantum states

The role of nanoparticle structure and morphology in the dissolution kinetics and nutrient release of nitrate‑doped calcium phosphate nanofertilizers

Bio-inspired synthetic calcium phosphate (CaP) nanoparticles (NPs), mimicking the mineral component of bone and teeth, are emergent materials for sustainable applications in agriculture. These sparingly soluble salts show self-inhibiting dissolution processes in undersaturated aqueous media, the control at the molecular and nanoscale levels of which is not fully elucidated. Understanding the mechanisms of particle dissolution is highly relevant to the efcient delivery of macronutrients to the plants and crucial for developing a valuable synthesis-by-design approach. It has also implications in bone (de)mineralization processes. Herein, we shed light on the role of size, morphology and crystallinity in the dissolution behaviour of CaP NPs and on their nitrate doping for potential use as (P,N)-nanofertilizers. Spherical fully amorphous NPs and apatite-amorphous nanoplatelets (NPLs) in a core-crown arrangement are studied by combining forefront Small-Angle and Wide-Angle X-ray Total Scattering (SAXS and WAXTS) analyses. ­Ca2+ ion release rates difer for spherical NPs and NPLs demonstrating that morphology plays an active role in directing the dissolution kinetics. Amorphous NPs manifest a rapid loss of nitrates governed by surface-chemistry. NPLs show much slower release, paralleling that of ­Ca2+ ions, that supports both detectable nitrate incorporation in the apatite structure and dissolution from the core basal faces.Fondazione Cariplo 2016-0648FEDER/Ministerio de Ciencia, Innovacion y Universidades-Agencia Estatal de Investigacion (FEDER/MCIU/AEI, Spain) through the project NanoVIT RTI-2018-095794-A-C22FEDER/Ministerio de Ciencia, Innovacion y Universidades-Agencia Estatal de Investigacion (FEDER/MCIU/AEI, Spain) through the project NanoSmart RYC-2016-21042FEDER/MCIU/AEI within the Juan de la Cierva Program (JdC2017