Generalized boundary strata classes

We describe a generalization of the usual boundary strata classes in the Chow ring of $\overline{\mathcal{M}}_{g,n}$. The generalized boundary strata classes additively span a subring of the tautological ring. We describe a multiplication law satisfied by these classes and check that every double ramification cycle lies in this subring.Comment: For the Proceedings of the 2017 Abel Symposium, 10 page

Unjamming a granular hopper by vibration

We present an experimental study of the outflow of a hopper continuously vibrated by a piezoelectric device. Outpouring of grains can be achieved for apertures much below the usual jamming limit observed for non vibrated hoppers. Granular flow persists down to the physical limit of one grain diameter, a limit reached for a finite vibration amplitude. For the smaller orifices, we observe an intermittent regime characterized by alternated periods of flow and blockage. Vibrations do not significantly modify the flow rates both in the continuous and the intermittent regime. The analysis of the statistical features of the flowing regime shows that the flow time significantly increases with the vibration amplitude. However, at low vibration amplitude and small orifice sizes, the jamming time distribution displays an anomalous statistics

Growth of bifidobacteria in mammalian milk

Microbial colonization of the mammalian intestine begins at birth, when from a sterile state a newborn infant is exposed to an external environment rich in various bacterial species. An important group of intestinal bacteria comprises bifidobacteria. Bifidobacteria represent major intestinal microbiota during the breast-feeding period. Animal milk contains all crucial nutrients for babies’ intestinal microflora. The aim of our work was to test the influence of different mammalian milk on the growth of bifidobacteria. The growth of seven strains of bifidobacteria in human milk, the colostrum of swine, cow’s milk, sheep’s milk, and rabbit’s milk was tested. Good growth accompanied by the production of lactic acid was observed not only in human milk, but also in the other kinds of milk in all three strains of Bifidobacterium bifidum of different origin. Human milk selectively supported the production of lactic acid of human bifidobacterial isolates, especially the Bifidobacterium bifidum species. The promotion of bifidobacteria by milk is species-specific. Human milk contains a key factor for the growth of specific species or strains of human-origin bifidobacteria compared to other kinds of milk. In contrast, some components (maybe lysozyme) of human milk inhibited the growth of Bifidobacterium animalis. Animal-origin strains of bifidobacteria were not able to significantly grow even in milk of animal origin, with the exception of B. animalis subsp. lactis 1,2, which slightly grew in sheep’s milk

Intruder mobility in a vibrated granular packing

We study experimentally the dynamics of a dense intruder sinking under gravity inside a vibrated 2D granular packing. The surrounding flow patterns are characterized and the falling trajectories are interpreted in terms of an effectivive friction coefficient related to the intruder mean descent velocity (flow rules). At higher confining pressures i.e. close to jamming, a transition to intermittent dynamics is evidenced and displays anomalous "on-off" blockade statistics. A systematic analysis of the flow rules, obtained for different intruder sizes, either in the flowing regime or averaged over the flowing and blockade regimes, strongly suggest the existence of non-local properties for the vibrated packing rheology.

Building governance and energy efficiency: Mapping the interdisciplinary challenge

Improving the energy efficiency of multi-owned properties (MoPs)—commonly known as apartment or condominium buildings—is central to the achievement of European energy targets. However, little work to date has focused on how to facilitate retrofit in this context. Drawing on interdisciplinary Social Sciences and Humanities expertise in academia, policy and practice, this chapter posits that decision-making processes within MoPs might provide a key to the retrofit challenge. Existing theories or models of decision-making, applied in the MoP context, might help to explain how collective retrofit decisions are taken—or overlooked. Insights from case studies and practitioners are also key. Theories of change might then be employed to develop strategies to facilitate positive retrofit decisions. The chapter maps the issues and sets an agenda for further interdisciplinary research in this novel area

Molecular Techniques Reveal Wide Phyletic Diversity of Heterotrophic Microbes Associated with Discodermia spp. (Porifera: Demospongiae)

Sponges are well known to harbor large numbers of heterotrophic microbes within their mesohyl. Studies to determine the diversity of these associated microbes have been attempted for only a few shallow water species. We cultured various microorganisms from several species of Discodermia collected from deep water using the \u27Johnson-Sea-Link\u27 manned submersibles, and characterised them by standard microbiological identification methods. Characterisation of a small proportion (ca. 10%) of the total and potential eubacterial isolate collection with molecular systematics techniques revealed a wide diversity of microbes. Phylogenetic analyses of 32 small subunit (SSU) 16S-like rRNA gene sequences from different micorbes indicated high levels of taxonomic diversity assoiated with this genus of sponge. For example, bacteria from at least five cubacterial subdivisions - gamma, alpha, beta, Cytophaga and Gram positive - were isolated from the mesohyl of Discodermia. Several strains were unidentifiable from current sequence databases. No overlap was found between sequences of 24 isolates and 8 sequences obtained by PCR and cloning directly from sponge samples. The abundance and diversity of microbes associated with sponges such as Discodermia suggest that they may play important roles in marine microbial ecology, dispersal and evolution

Voigt effect-based wide-field magneto-optical microscope integrated in a pump-probe experimental setup

In this work, we describe an experimental setup for a spatially resolved pump-probe experiment with an integrated wide-field magneto-optical (MO) microscope. The MO microscope can be used to study ferromagnetic materials with both perpendicular-to-plane and in-plane magnetic anisotropy via polar Kerr and Voigt effects, respectively. The functionality of the Voigt effect-based microscope was tested using an in-plane magnetized ferromagnetic semiconductor (Ga,Mn)As. It was revealed that the presence of mechanical defects in the (Ga,Mn)As epilayer alters significantly the magnetic anisotropy in their proximity. The importance of MO experiments with simultaneous temporal and spatial resolutions was demonstrated using a (Ga,Mn)As sample attached to a piezoelectric transducer, which produces a voltage-controlled strain. We observed a considerably different behavior in different parts of the sample that enabled us to identify sample parts where the epilayer magnetic anisotropy was significantly modified by the presence of the piezoelectric transducer and where it was not. Finally, we discuss the possible applicability of our experimental setup for the research of compensated antiferromagnets, where only MO effects even in magnetic moments are present

The middle-out perspective:an approach to formalise 'normal practice' in public health advocacy

AIMS: The middle-out perspective (MOP) provides a lens to examine how actors positioned between government (top) and individuals (bottom) act to promote broader societal changes from the middle-out (rather than the top-down or bottom-up). The MOP has been used in recent years in the fields of energy, climate change, and development studies. We argue that public health practitioners involved with advocacy activities and creating alliances to amplify health promotion actions will be familiar with the general MOP concept if not the formal name. The article aims to demonstrate this argument. METHODS: This article introduces the MOP conceptual framework and customises it for a public health audience by positioning it among existing concepts and theories for actions within public health. Using two UK case studies (increasing signalised crossing times for pedestrians and the campaign for smoke-free legislation), we illustrate who middle actors are and what they can do to result in better public health outcomes. RESULTS: These case studies show that involving a wider range of middle actors, including those not traditionally involved in improving the public's health, can broaden the range and reach of organisations and individuals involving in advocating for public health measures. They also demonstrate that middle actors are not neutral. They can be recruited to improve public health outcomes, but they may also be exploited by commercial interests to block healthy policies or even promote a health-diminishing agenda. CONCLUSION: Using the MOP as a formal approach can help public health organisations and practitioners consider potential 'allies' from outside traditional health-related bodies or professions. Formal mapping can expand the range of who are considered potential middle actors for a particular public health issue. By applying the MOP, public health organisations and staff can enlist the additional leverage that is brought to bear by involving additional middle actors in improving the public's health