Where does our fascination for 'heritage' originate? This groundbreaking comparative study of preservation in France, Germany and England looks beyond national borders to reveal how the idea of ...heritage emerged from intense competition and collaboration in a global context. Astrid Swenson follows the 'heritage-makers' from the French Revolution to the First World War, revealing the importance of global networks driving developments in each country. Drawing on documentary, literary and visual sources, the book connects high politics and daily life and uncovers how, through travel, correspondence, world fairs and international congresses, the preservationists exchanged ideas, helped each other campaign and dreamed of establishing international institutions for the protection of heritage. Yet, these heritage-makers were also animated by fierce rivalry as international tension grew. This mixture of international collaboration and competition created the European culture of heritage, which defined preservation as integral to modernity, and still shapes current institutions and debates.
Heme is a ubiquitous and essential iron containing metallo-organic cofactor required for virtually all aerobic life. Heme synthesis is initiated and completed in mitochondria, followed by certain ...covalent modifications and/or its delivery to apo-hemoproteins residing throughout the cell. While the biochemical aspects of heme biosynthetic reactions are well understood, the trafficking of newly synthesized heme-a highly reactive and inherently toxic compound-and its subsequent delivery to target proteins remain far from clear. In this review, we summarize current knowledge about heme biosynthesis and trafficking within and outside of the mitochondria.
Laboratory science requires careful maintenance of sterile reagents and tools as well as the sterilization of waste prior to disposal. However, steam autoclaves typically used for this purpose may ...not be readily accessible to everyone in the scientific community, such as K-12 teachers, researchers in the field, students in under-funded laboratories, or persons in the developing world who lack funding and resources. This work examines the use of commercial electric pressure cookers as an alternative method for the sterilization of media, instruments, and waste. Four commonly available brands of pressure cooker were tested for their ability to sterilize microbiological media, a variety of metal instruments, and high-titer microbial cultures. All four pressure cookers were able to sterilize these starting materials as well as a range of microbial types, including Gram-positive bacteria, Gram-negative bacteria, filamentous fungi, unicellular fungi, and mixed environmental samples. Only the Instant Pot, however, was able to sterilize autoclave tester ampoules of Geobacillus stearothermophilus spores. These results suggest that, depending on the nature of the work undertaken, store-bought pressure cookers can be an appropriate substitute for commercial autoclaves. Their adoption may also help increase the accessibility of science to a broader range of investigators.
Summary
Multicellular development requires the careful orchestration of gene expression to correctly create and position specialized cells. In the filamentous cyanobacterium Anabaena sp. strain PCC ...7120, nitrogen‐fixing heterocysts are differentiated from vegetative cells in a reproducibly periodic and physiologically relevant pattern. While many genetic factors required for heterocyst development have been identified, the role of HetZ has remained unclear. Here, we present evidence to clarify the requirement of hetZ for heterocyst production and support a model where HetZ functions in the patterning stage of differentiation. We show that a clean, nonpolar deletion of hetZ fails to express the developmental genes hetR, patS, hetP and hetZ correctly and fails to produce heterocysts. Complementation and overexpression of hetZ in a hetP mutant revealed that hetZ was incapable of bypassing hetP, suggesting that it acts upstream of hetP. Complementation and overexpression of hetZ in a hetR mutant, however, demonstrated bypass of hetR, suggesting that it acts downstream of hetR and is capable of bypassing the need for hetR for differentiation irrespective of nitrogen status. Finally, protein–protein interactions were observed between HetZ and HetR, Alr2902 and HetZ itself. Collectively, this work suggests a regulatory role for HetZ in the patterning phase of cellular differentiation in Anabaena.
Anabaena sp. strain PCC 7120 differentiates nitrogen‐fixing heterocysts from vegetative cells in a reproducibly periodic and physiologically relevant pattern. HetZ is known to impact heterocyst development. In this study, we clarify the placement of HetZ in the genetic program controlling development and find that it acts downstream of HetR, the master regulator of differentiation and upstream of HetP, a factor involved in the commitment to a differentiated cell fate, at the transition between patterning and commitment.
Permeable sediments, which represent more than 50% of the continental shelves, have been largely neglected as a potential source of Fe in current global estimates of benthic dissolved iron (Fe
d
) ...fluxes. There are open questions regarding the effects of a range of factors on Fe
d
fluxes from these deposits, including seasonal dynamics and the role of bioirrigation. To address these gaps, we performed laboratory-based sediment incubation experiments with muddy sands during summer (21 °C) and winter (7 °C). We used bioirrigation mimics to inject overlying water into the permeable sediment with patterns resembling the bioirrigation activity of the prolific bioturbating polychaete,
Clymenella torquata
. Newly developed in-line Fe accumulators were used to estimate Fe fluxes with a recirculating set-up. We found high Fe
d
fluxes from sandy sediments, especially in benthic chambers with simulated bioirrigation. In the winter fluxes reached >200 µmol Fe
d
m
-2
d
-1
at the onset of irrigation and then decreased over the course of a 13-day experiment while in the summer fluxes from irrigated sediments reached >100 µmol Fe
d
m
-2
d
-1
and remained high throughout a 7-day experiment. Despite different geochemical expressions of Fe-S cycling and resulting porewater Fe
d
concentrations in winter and summer, large Fe
d
fluxes were sustained during both seasons. Solid-phase and porewater concentration profiles showed that maximum concentrations of key constituents, including total solid-phase reactive Fe, and porewater Fe
d
and ammonium, were located closer to the sediment water interface (SWI) in irrigated cores than in non-irrigated cores due to the upward advective transport of dissolved porewater constituents. This upward transport also facilitated Fe
d
fluxes out of the sediments, especially during times of active pumping. Our study demonstrates the potential for large Fe
d
fluxes from sandy sediments in both summer and winter, despite relatively low standing stocks of labile organic matter and porewater Fe
d
. The primary driver of these high fluxes was advective porewater transport, in our study induced by the activity of infaunal organisms. These results suggest that permeable sediments, which dominate shelf regions, must be explicitly considered in global estimates of benthic Fe
d
fluxes, and cannot be simply extrapolated from estimates based on muddy sediments.
The exchange of trace gases between the Earth's surface and atmosphere strongly influences atmospheric composition. Airborne eddy covariance can quantify surface fluxes at local to regional scales ...(1–1000 km), potentially helping to bridge gaps between top-down and bottom-up flux estimates and offering novel insights into biophysical and biogeochemical processes. The NASA Carbon Airborne Flux Experiment (CARAFE) utilizes the NASA C-23 Sherpa aircraft with a suite of commercial and custom instrumentation to acquire fluxes of carbon dioxide, methane, sensible heat, and latent heat at high spatial resolution. Key components of the CARAFE payload are described, including the meteorological, greenhouse gas, water vapor, and surface imaging systems. Continuous wavelet transforms deliver spatially resolved fluxes along aircraft flight tracks. Flux analysis methodology is discussed in depth, with special emphasis on quantification of uncertainties. Typical uncertainties in derived surface fluxes are 40–90 % for a nominal resolution of 2 km or 16–35 % when averaged over a full leg (typically 30–40 km). CARAFE has successfully flown two missions in the eastern US in 2016 and 2017, quantifying fluxes over forest, cropland, wetlands, and water. Preliminary results from these campaigns are presented to highlight the performance of this system.
Asthma, like many inflammatory disorders, is affected by psychological stress, suggesting that reciprocal modulation may occur between peripheral factors regulating inflammation and central neural ...circuitry underlying emotion and stress reactivity. Despite suggestions that emotional factors may modulate processes of inflammation in asthma and, conversely, that peripheral inflammatory signals influence the brain, the neural circuitry involved remains elusive. Here we show, using functional magnetic resonance imaging, that activity in the anterior cingulate cortex and insula to asthma-relevant emotional, compared with valence-neutral stimuli, is associated with markers of inflammation and airway obstruction in asthmatic subjects exposed to antigen. This activation accounts for ≥40% of the variance in the peripheral markers and suggests a neural basis for emotion-induced modulation of airway disease in asthma. The anterior cingulate cortex and insula have been implicated in the affective evaluation of sensory stimulation, regulation of homeostatic responses, and visceral perception. In individuals with asthma and other stress-related conditions, these brain regions may be hyperresponsive to disease-specific emotional and afferent physiological signals, which may contribute to the dysregulation of peripheral processes, such as inflammation.
An essential dimension of food tasting (i.e., flavor) is olfactory stimulation by volatile organic compounds (VOCs) emitted therefrom. Here, we developed a novel analytical method based on ...solid-phase microextraction (SPME) sampling in argon-filled gas sampling bags with direct gas chromatography⁻mass spectrometry (GC-MS) determination to profile the volatile constituents of 31 homemade preserves prepared in South Dakota (USA) during the period 1950⁻1953. Volatile profiles varied considerably, but generally decreased in detected compounds, complexity, and intensity over three successive 2-h SPME sampling periods. Volatile profiles were generally predominated by aldehydes, alcohols, esters, ketones, and organic acids, with terpenoids constituting much of the pickled cucumber volatiles. Bisphenol-A (BPA) was also serendipitously detected and then quantified in 29 samples, at levels ranging from 3.4 to 19.2 μg/kg, within the range of levels known to induce endocrine disruption effects. Absence of BPA in two samples was attributed to their lids lacking plastic liners. As the timing of their preparation coincides with the beginning of BPA incorporation into consumer products, these jars may be some of the first BPA-containing products in the USA. To the best of our knowledge, this is the first effort to characterize BPA in and volatile profiles of rare historical foods with SPME.
Although rhinovirus (RV) infections can cause asthma exacerbations and alter lower airway inflammation and physiology, it is unclear how important bronchial infection is to these processes. To study ...the kinetics, location, and frequency of RV appearance in lower airway tissues during an acute infection, immunohistochemistry and quantitative polymerase chain reaction analysis were used to analyze the presence of virus in cells from nasal lavage, sputum, bronchoalveolar lavage, bronchial brushings, and biopsy specimens from 19 subjects with an experimental RV serotype 16 (RV16) cold. RV was detected by polymerase chain reaction analysis on cells from nasal lavage and induced sputum samples from all subjects after RV16 inoculation, as well as in 5 of 19 bronchoalveolar lavage cell samples and in 5 of 18 bronchial biopsy specimens taken 4 days after virus inoculation. Immunohistochemistry detected RV16 in 39 and 36% of all biopsy and brushing samples taken 4 and 15 days, respectively, after inoculation. Infected cells were primarily distributed in discrete patches on the epithelium. These results confirm that infection of lower airway tissues is a frequent finding during a cold and further demonstrate a patchy distribution of infected cells, a pattern similar to that reported in upper airway tissues.
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