The Hunt for Red 'Microba: Identification of Microorganisms involved in 'Red Heat' Contamination of Salt-Cured Hides

Content: “Red heat” is an industry term that describes the appearance of mostly red-pink coloured macroscopic microbial colonies on salt-cured hides and skins. Red heat-affected stock is undesirable as the resultant leather often shows obvious defects; but why this contamination is only superficial in other instances remains unclear. Previous work has focused on pigmented halophiles (‘salt-loving’ microbes) isolated from curing salts as the primary culprit. However, the identity of causative agents remains unspecified. Also, the involvement of non-pigmented microbes, and of microbes native to hides and skins, could be better understood. Thus, an investigation of the microbial communities that inhabit untreated bovine hide, curing salt, unaffected salt-cured bovine hide, and red heat-affected cured hide is proposed to uncover the microbial agents responsible for this contamination. This project aims to define these microbial communities using both a culture-dependent and –independent approach. Methods of microbe identification focus on marker gene amplification and sequencing. This is in contrast to earlier work which was restricted solely to phenotypic analyses. The 16S ribosomal RNA gene marker is used to identify members of Bacteria and Archaea, while the 18S and ITS2 regions of the fungal ribosomal RNA operon are targeted to detect fungi. Metagenomic amplicon sequencing using the Illumina MiSeq platform employs these same markers to determine taxonomic composition and relative abundance. Preliminary results from culturing identified different dominant species in curing salts screened for microbial growth. In agreement with earlier culture-based studies, these isolates were mostly pigmented, highly salt-tolerant members of the halophilic archaea of family Halobacteriaceae, as determined by marker gene sequencing. However, in agreement with more recent work within food preservation technology, nonpigmented isolates of halophilic archaea of genus Natrinema and bacterial genus Chromohalobacter were also found. It was also revealed that non-pigmented, quick-growing, salt-tolerant, proteolytic microbes were easily cultured from red heat-affected hide, most of the isolates were identified by marker gene sequencing as bacterial Pseudomonas halophila or Salicola. To determine red heat-causing microbes, future work involves the screening of isolates for extracellular enzyme activity; the most likely cause of red heat-associated damage. Sterile-salted hide samples will be inoculated with selected individual and combinations of isolates, and then further examined using confocal microscopy to check for reproducibility of red heat-associated damage. Take-Away: Different microbial species are found in different curing salts. Not all microbes involved in 'red heat' contamination are pigmented. The purpose is the possibility to overcome all the restrictions connected with the pin-wheel machine, the improvement of actual EN ISO methods of leather measurement and a better instrument to define tolerances considering the couple leather-machine

The use of natural products in the leather industry: Depilation without damage

Content: Sheepskin, a by-product of the meat industry, is then often processed to leather, primarily for the clothing industry. Where the tanneries are distant from the abattoirs and freezing works, the raw skins have to be transported long distances to be processed. In warm weather, there is the potential for putrefaction of the skins which then have to be disposed of at a cost. Depilation, the first step of leather processing, is designed to remove the wool from the skin without damaging it. Conventional depilation involves the use of strong alkali and sulfides, that are harmful to both the environment and the personnel carrying out the process due to the potential production of hydrogen sulfide, a toxic, flammable gas. To solve this problem, scientists have been looking to depilate skins using enzymes as these are environmentally friendly. Various enzymes, such as collagenase, keratinase, protease and lipase have been shown to be able to remove hair from skin, but unfortunately usually damage it. Furthermore, at present, they are not cost effective at an industrial level. We have found a simple solution, a derivative of a dairy by-product, that prevents putrefaction, preserving the skin for days at room temperature. In addition, it allows easy removal of the wool from the skin. Scanning electron microscopy showed there was no obvious damage to the surface of the depilated skin and that the wool is cleanly removed from the hair follicle. To assess any less visible damage that may have occurred as a result of soaking the skin, biochemical analyses were carried out to measure the changes to the amino acid composition, collagen crosslinks and proteoglycan concentrations of the depilated skins. Sheepskin depilated with this method was processed to leather and its physical properties such as tear, and tensile strength analysed. Culture dependent methods were used to isolate the microorganisms present in the solution after depilation, showed that only four main species were consistently found in the depilation fluid and on the skins. Metagenomic analysis, confirmed these findings and was used to follow the changes in the microbiome during the course of depilation. This presentation will describe the progress that has been made to understand the science behind these observations and compare the properties of skins depilated using this method with those depilated using the traditional beamhouse process. Take-Away: We are using a natural product to depilate sheepskin. The sheepskin is also preserved while depilation. Microscopy, chemical analyses, physical tests, and metagenomics analysis were done to understand the process

Historical geography II: traces remain

The second report in this series turns to focus on the trace in relation to life-writing and biography in historical geography and beyond. Through attention to tracing journeys, located moments and listening to the presence of ghosts (Ogborn, 2005), this report seeks to highlight the range of different ways in which historical geographers have explored lives, deaths, and their transient traces through varied biographical terrains. Continuing to draw attention in historical geography to the darkest of histories, this piece will pivot on moments of discovering the dead to showcase the nuanced ways in which historical geography is opening doors into uncharted lives and unspoken histories

Sharpea and Kandleria are lactic acid producing rumen bacteria that do not change their fermentation products when co-cultured with a methanogen

peer-reviewedSharpea and Kandleria are associated with rumen samples from low-methane-emitting sheep. Four strains of each genus were studied in culture, and the genomes of nine strains were analysed, to understand the physiology of these bacteria. All eight cultures grew equally well with d-glucose, d-fructose, d-galactose, cellobiose, and sucrose supplementation. d-Lactate was the major end product, with small amounts of the mixed acid fermentation products formate, acetate and ethanol. Genes encoding the enzymes necessary for this fermentation pattern were found in the genomes of four strains of Sharpea and five of Kandleria. Strains of Sharpea produced traces of hydrogen gas in pure culture, but strains of Kandleria did not. This was consistent with finding that Sharpea, but not Kandleria, genomes contained genes coding for hydrogenases. It was speculated that, in co-culture with a methanogen, Sharpea and Kandleria might change their fermentation pattern from a predominately homolactic to a predominately mixed acid fermentation, which would result in a decrease in lactate production and an increase in formation of acetate and perhaps ethanol. However, Sharpea and Kandleria did not change their fermentation products when co-cultured with Methanobrevibacter olleyae, a methanogen that can use both hydrogen and formate, and lactate remained the major end product. The results of this study therefore support a hypothesis that explains the link between lower methane yields and larger populations of Sharpea and Kandleria in the rumens of sheep

Sr-Nd-Pb-Hf isotope results from ODP Leg 187: Evidence for mantle dynamics of the Australian-Antarctic Discordance and origin of the Indian MORB source

New high precision PIMMS Hf and Pb isotope data for 14–28 Ma basalts recovered during ODP Leg 187 are compared with zero-age dredge samples from the Australian-Antarctic Discordance (AAD). These new data show that combined Nd-Hf isotope systematics can be used as an effective discriminant between Indian and Pacific MORB source mantle domains. In particular, Indian mantle is displaced to lower εNd and higher εHf ratios compared to Pacific mantle. As with Pb isotope plots, there is almost no overlap between the two mantle types in Nd-Hf isotope space. On the basis of our new Nd-Hf isotope data, we demonstrate that Pacific MORB-source mantle was present near the eastern margin of the AAD from as early as 28 Ma, its boundary with Indian MORB-source mantle coinciding with the eastern edge of a basin-wide arcuate depth anomaly that is centered on the AAD. This observation rules out models requiring rapid migration of Pacific MORB mantle into the Indian Ocean basin since separation of Australia from Antarctica. Although temporal variations in isotopic composition can be discerned relative to the fracture zone boundary of the modern AAD at 127°E, the distribution of different compositional groups appears to have remained much the same relative to the position of the residual depth anomaly for the past 30 m.y. Thus significant lateral flow of mantle along the ridge axis toward the interface appears unlikely. Instead, the dynamics that maintain both the residual depth anomaly and the isotopic boundary between Indian and Pacific mantle are due to eastward migration of the Australian and Antarctic plates over a stagnated, but slowly upwelling, slab oriented roughly orthogonal to the ridge axis. Temporal and spatial variations in the compositions of Indian MORB basalts within the AAD can be explained by progressive displacement of shallower Indian MORB-source mantle by deeper mantle having a higher εHf composition ascending ahead of the upwelling slab. Models for the origin of the distinctive composition of the Indian MORB-source based on recycling of a heterogeneous enriched component that consist of ancient altered ocean crust plus<10% pelagic sediment are inconsistent with Nd-Hf isotope systematics. Instead, the data can be explained by a model in which Indian mantle includes a significant proportion of material that was processed in the mantle wedge above a subduction zone and was subsequently mixed back into unprocessed upper mantle

Filmic geographies: audio-visual, embodied-material

Although conventionally described as a ‘visual’ method, film-making is also increasingly used within research on embodiment. However, much remains to be said about the ability of filmic methods to enhance researchers’ capacity to think and research through the body. Drawing on my experience of making four research films, in this paper, I attempt to advance this agenda in three steps. First, I introduce anthropological work on the filming body to shed light on the technologically-mediated encounters that enfold around a camera and discuss how they might inform geographical thinking. Second, I describe the corporeally-mediated object ecologies that take shape within the filming setting and highlight how a camera might make objects ‘speak’. Finally, I discuss the affective dimension of screening research films to research participants and the contribution of such intense events to the articulation of collective matters of concerns. Through these three themes, I make the case for understanding knowledge production as located not merely in encounters with filmed audio-visual content, but also in the embodied-material encounters of bodies and objects around the filming and screening apparatus. I finally discuss the implications of these reflections for conceptualising the ‘body’ within embodied methods in social and cultural geography

The Chemical Distribution in a Subluminous Type Ia Supernova: HST Images of the SN 1885 Remnant

We present HST images of the remnant of SN 1885 seen in absorption against M31's bulge via resonance lines of Ca I, Ca II, Fe I, and Fe II. Viewed in CaII H & K line absorption, the remnant appears as a nearly black circular spot with an outermost angular radius of 0.40" +/- 0.025" implying r = 1.52 pc and a 120 yr average expansion velocity of 12400 +/-1400 km/s. The strongest Ca II absorption is organized in a broken ring structure with a radius of 0.20" (=6000 km/s) with several apparent absorption `clumps' of an angular size near the pixel scale of 0.05" (= 1500 km/s). The detection of Ca II clumps is the first direct evidence for some instabilities and the existence of a deflagration phase in SNe Ia or, alternatively, mixing induced by radioactive decay of 56^Ni over time scales of seconds or days. However, the degree of mixing allowed by the observed images is much smaller than current 3D calculations for Rayleigh-Taylor dominated deflagration fronts. The images also require a central region of no or little Ca but iron group elements indicative of burning under sufficiently high densities for electron capture taking place, i.e., burning prior to a significant pre-expansion of the WD.Comment: 18 pages, 14 figures. Accepted for publication in Ap

Temperature dependence of the picosecond spin Seebeck effect

We performed temperature-dependent optical pump–THz emission measurements in Y₃Fe₅O₁₂ (YIG)|Pt from 5 K to room temperature in the presence of an externally applied magnetic field. We study the temperature dependence of the spin Seebeck effect and observe a continuous increase as temperature is decreased, opposite to what is observed in electrical measurements, where the spin Seebeck effect is suppressed as 0 K is approached. By quantitatively analyzing the different contributions, we isolate the temperature dependence of the spin-mixing conductance and observe features that are correlated with the bands of magnon spectrum in YIG

Cheeky Witnessing

Feminists witness legal worlds as they observe, document, and share nothing less than the reproduction of life itself. The world of the abortion trail, where people and things move across borders to change life’s reproduction, has generated a rich plurality of feminist witnessing. In observing how feminist activists improvise with sources, figures and objects of legal consciousness on the abortion trail, this paper seeks to contribute to critical understanding of that plurality, particularly as it emerges in diaspora space. Focusing on Murphy’s concept of immodest witnessing, with its attention to bodies, protocols and apparatuses as constituents of knowledge, the paper thinks with the diasporic feminist activist performance group, Speaking of I.M.E.L.D.A., about how they used self-examination, collective collaboration, and knowledge-sharing on the trail to repeal of Ireland’s Eighth Amendment. The paper argues that their improvisation with legal consciousness of reproductive choice enacts ‘cheeky witnessing’. Cheeky witnessing has three dynamics as a method of observation. First, it is messy and irreverent in innovating with names to display the mixed genealogies of sources of feminist knowledge. Second, cheeky witnessing generates novel subject-figures, such as migrant cleaners, who make knowing connections between different reproductive labourers as observers of the trail in diaspora space. Third, cheeky witnessing places funny objects, knickers in this instance, so as to join up particular public locations and make them more, if unevenly, comfortable for sexual and reproductive bodies. Cheeky witnessing show us how committed and partial practices play a role in speaking across interests and experiences, in stretching the legal imagination, and in sustaining the everyday grind of making a better world