Emulsion formation and stabilization by biomolecules: the leading role of cellulose

Emulsion stabilization by native cellulose has been mainly hampered because of its insolubility in water. Chemical modification is normally needed to obtain water-soluble cellulose derivatives. These modified celluloses have been widely used for a range of applications by the food, cosmetic, pharmaceutic, paint and construction industries. In most cases, the modified celluloses are used as rheology modifiers (thickeners) or as emulsifying agents. In the last decade, the structural features of cellulose have been revisited, with particular focus on its structural anisotropy (amphiphilicity) and the molecular interactions leading to its resistance to dissolution. The amphiphilic behavior of native cellulose is evidenced by its capacity to adsorb at the interface between oil and aqueous solvent solutions, thus being capable of stabilizing emulsions. In this overview, the fundamentals of emulsion formation and stabilization by biomolecules are briefly revisited before different aspects around the emerging role of cellulose as emulsion stabilizer are addressed in detail. Particular focus is given to systems stabilized by native cellulose, either molecularly-dissolved or not (Pickering-like effect).Financially support by the Portuguese Foundation for Science and Technology, FCT, via the projects PTDC/AGR-TEC/4814/2014, PTDC/ASP-SIL/30619/2017 and researcher grant IF/01005/2014. RISE Research Institutes of Sweden AB and PERFORM, a competence platform in Formulation Science at RISE, are acknowledged for additional financing. This research has been supported by Treesearch.se.info:eu-repo/semantics/publishedVersio

Chiral surfaces self-assembling in one-component systems with isotropic interactions

We show that chiral symmetry can be broken spontaneously in one-component systems with isotropic interactions, i.e. many-particle systems having maximal a priori symmetry. This is achieved by designing isotropic potentials that lead to self-assembly of chiral surfaces. We demonstrate the principle on a simple chiral lattice and on a more complex lattice with chiral super-cells. In addition we show that the complex lattice has interesting melting behavior with multiple morphologically distinct phases that we argue can be qualitatively predicted from the design of the interaction.Comment: 4 pages, 4 figure

AULACOSEIRA SKVORTZOWII SP. NOV. (BACILLARIOPHYTA), A POORLY UNDERSTOOD DIATOM FROM LAKE BAIKAL, RUSSIA 1

Aulacoseira skvortzowii sp. nov. is a diatom taxon present in modern plankton assemblages and sedimentary deposits from Lake Baikal, Russia. It has been previously reported as A. islandica (O. MÜll.) Simonsen, A. islandica ssp. helvetica (O. MÜll.) Simonsen, a sporangial frustule of A. baicalensis (K. Meyer) Simonsen, and Aulacoseira “spore”. However, its microstructure, ecology, and ability to form true resting spores provide ample criteria to describe this diatom as Aulacoseira skvortzowii sp. nov.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65810/1/j.0022-3646.1996.00165.x.pd

Designing isotropic interactions for self-assembly of complex lattices

We present a direct method for solving the inverse problem of designing isotropic potentials that cause self-assembly into target lattices. Each potential is constructed by matching its energy spectrum to the reciprocal representation of the lattice to guarantee that the desired structure is a ground state. We use the method to self-assemble complex lattices not previously achieved with isotropic potentials, such as a snub square tiling and the kagome lattice. The latter is especially interesting because it provides the crucial geometric frustration in several proposed spin liquids.Comment: 4 pages, 3 figure

Simulation of the White Dwarf -- White Dwarf galactic background in the LISA data

LISA (Laser Interferometer Space Antenna) is a proposed space mission, which will use coherent laser beams exchanged between three remote spacecraft to detect and study low-frequency cosmic gravitational radiation. In the low-part of its frequency band, the LISA strain sensitivity will be dominated by the incoherent superposition of hundreds of millions of gravitational wave signals radiated by inspiraling white-dwarf binaries present in our own galaxy. In order to estimate the magnitude of the LISA response to this background, we have simulated a synthesized population that recently appeared in the literature. We find the amplitude of the galactic white-dwarf binary background in the LISA data to be modulated in time, reaching a minimum equal to about twice that of the LISA noise for a period of about two months around the time when the Sun-LISA direction is roughly oriented towards the Autumn equinox. Since the galactic white-dwarfs background will be observed by LISA not as a stationary but rather as a cyclostationary random process with a period of one year, we summarize the theory of cyclostationary random processes and present the corresponding generalized spectral method needed to characterize such process. We find that, by measuring the generalized spectral components of the white-dwarf background, LISA will be able to infer properties of the distribution of the white-dwarfs binary systems present in our Galaxy.Comment: 14 pages and 6 figures. Submitted to Classical and Quantum Gravity (Proceedings of GWDAW9

Sexually transmitted infections (STI) in men who have sex with men (MSM)

The impact of increasingly efficient antiretroviral therapy (ART) on survival and general well-being has contributed to a "business as usual" attitude to sex among men who have sex with men (MSM). There has been a recent marked increase of sexually transmitted infections (STI) including syphilis, LGV and Hepatits C among MSM. STIs located in the oral cavity or rectum are asymptomatic in over 80% and 50%, respectively and these sites must be seen as important reservoirs. On the other hand severe proctitis may be mistreated as inflammatory bowel disease without adequate medical history and testing. Due to the reappearance of syphilis, all genital ulcers, non-itching exanthema and severe disease symptoms (e.g. fever, fatigue, lymphadenopathy, hepato-splenomegaly, increased liver enzymes, neurological and ophthalmologic symptoms without other explanations) should lead to testing for syphilis. There is a marked association between STIs and HIV. Syphilis, LGV and Hepatits C are strongly overrepresented in HIV positive MSM, while gonorrhoea, LGV and syphilis increase the HIV susceptibility. Syphilis leads to increased viral load in HIV positive. The major risk factors for Hepatitis B are number of sex partners and receptive anal intercourse. High grade Human Papilloma Virus (HPV) anal lesions can progress to cancer. There is a 30 fold increase risk for anal cancer among MSM, a risk that is doubled in HIV infection, making anal cancer one of the most common non-AIDS tumors. All MSM should be offered Hepatitis A and B vaccination and the inclusion of boys in HPV vaccination programs must be considered. The aim of this article is to describe asymptomatic and symptomatic bacterial and viral STIs of the oral cavity, penis/urethra and rectum and the sexually transmittable viral Hepatitis and HIV in MSM and to inspire the medical establishment to adhere to testing guidelines in this group. This article is built on a review of published findings, the presentation of own data on Gonorrhoea and chlamydia and our own experience in treating all STIs including HIV in MSM since 1982 at a Gay Men's Health Clinic (Venhälsan) at Stockholm South General Hospital, Sweden

Water Quality (2000-08) and Historical Phosphorus Concentrations from Paleolimnological Studies of Swamp and Speckled Trout Lakes, Grand Portage Reservation, Northeastern Minnesota

This is a technical study to determine reference conditions for water quality on the Grand Portage Reservation. It has some historical interest related to human settlement, as well as data useful for monitoring water quality in the future. Reston, VA: U.S. Department of the Interior, U.S. Geological Survey.A paleolimnological approach was taken to aid the Grand Portage Reservation, in northeastern Minnesota, in determining reference conditions for lakes on the reservation. The U.S. Geological Survey, in cooperation with the Grand Portage Band of Chippewa Indians and the Science Museum of Minnesota, conducted a study to describe water quality (2000–08) and historical total phosphorus concentrations (approximately 1781–2006) for Swamp and Speckled Trout Lakes. Results from this study may be used as a guide in establishing nutrient criteria in these and other lakes on the Grand Portage Reservation. Historical phosphorus concentrations were inferred through paleolimnological reconstruction methods involving diatom analysis and lead-210 dating of lake-sediment cores. Historical diatom-inferred total phosphorus concentrations in Swamp Lake ranged from 0.017 to 0.025 milligrams per liter (mg/L) based on diatom assemblages in sediment samples dated 1781–2005. Historical diatom-inferred total phosphorus concentrations in Speckled Trout Lake ranged from 0.008 to 0.014 mg/L based on diatom assemblages in sediment samples dated 1825–2006. In both lakes, historical changes in diatom-inferred total phosphorus concentrations did not exceed model error estimates, indicating that there has been minimal change in total phosphorus concentrations in the two lakes over about two centuries. The pH and alkalinity values of waters in both lakes indicate that general water-quality conditions likely are not threatening fish or acid-intolerant forms of aquatic life. Lake-sediment cores from Swamp and Speckled Trout Lakes were collected in 2006 and dated back to 1781 for Swamp Lake and 1825 for Speckled Trout Lake. A large increase in sediment accumulation rate after 1960 likely was a result of logging along the northeastern shore of Swamp Lake in 1958. The diatom flora of Swamp Lake is very diverse with more than 280 diatom taxa found in the core samples. These diatoms included many rare or uncommon species and several unknown taxa. Minor increases in sediment accumulation rates in the Speckled Trout Lake core occurred between 1840 and 1880. These increases may have resulted from fires following droughts in northeastern Minnesota. Heinselman (1973) identified five periods of fire in the 1800s for the Boundary Waters Canoe Area, Minnesota: 1801, 1824, 1863–64, 1875, and 1894. Most of these fire periods followed prolonged droughts of subcontinental extent, including the 1864 drought. Similar to the Swamp Lake core, the diatom flora of the Speckled Trout Lake core was very diverse and dominated by softwater diatoms. More than 215 diatom taxa were found in the core samples including many rare or uncommon species and several unknown taxa. Results of loss-on-ignition analyses indicated that sediment from Swamp Lake historically has been dominated by the inorganic component with a shift to an organic component in modern sedimentation. Median values of recent (2000–08) total phosphorus concentrations in water-quality samples and diatom-inferred phosphorus in recent sedimentation in Swamp and Speckled Trout Lakes were similar. These similarities, coupled with strong analogues for subfossil diatom communities for both lakes within the 89 Minnesota lakes diatom transfer function, indicate that recent and historical diatom-inferred phosphorus reconstructions might be used to help establish reference conditions and nutrient criteria for Grand Portage Reservation lakes when a sampling program is designed to ensure representative phosphorus concentrations in water samples are comparable to diatom-inferred concentrations

Universality of striped morphologies

We present a method for predicting the low-temperature behavior of spherical and Ising spin models with isotropic potentials. For the spherical model the characteristic length scales of the ground states are exactly determined but the morphology is shown to be degenerate with checkerboard patterns, stripes and more complex morphologies having identical energy. For the Ising models we show that the discretization breaks the degeneracy causing striped morphologies to be energetically favored and therefore they arise universally as ground states to potentials whose Hankel transforms have nontrivial minima.Comment: 4 pages, 4 figure