Forehead Skin Blood Flow in Normal Neonates during Active and Quiet Sleep, Measured with a Diode Laser Doppler Instrument

Changes in forehead skin blood flow during active and quiet sleep were determined in 16 healthy neonates using a recently developed semi-conductor laser Doppler flow meter without light conducting fibres. Measurements were carried out at a postnatal age varying from 5 hours to 7 days. The two sleep states could be distinguished in 17 recordings. The mean skin blood flow values during active sleep were significantly higher (p<0.01) than those during quiet sleep, the mean increase being 28.1%. The variability of the flow signal, expressed as the coefficient of variation, changed significantly from 23.1% during active sleep to 18.2% during quiet sleep

Membrane Insertion for the Detection of Lipopolysaccharides: Exploring the Dynamics of Amphiphile-in-Lipid Assays

Shiga toxin-producing Escherichia coli is an important cause of foodborne illness, with cases attributable to beef, fresh produce and other sources. Many serotypes of the pathogen cause disease, and differentiating one serotype from another requires specific identification of the O antigen located on the lipopolysaccharide (LPS) molecule. The amphiphilic structure of LPS poses a challenge when using classical detection methods, which do not take into account its lipoglycan biochemistry. Typically, detection of LPS requires heat or chemical treatment of samples and relies on bioactivity assays for the conserved lipid A portion of the molecule. Our goal was to develop assays to facilitate the direct and discriminative detection of the entire LPS molecule and its O antigen in complex matrices using minimal sample processing. To perform serogroup identification of LPS, we used a method called membrane insertion on a waveguide biosensor, and tested three serogroups of LPS. The membrane insertion technique allows for the hydrophobic association of LPS with a lipid bilayer, where the exposed O antigen can be targeted for specific detection. Samples of beef lysate were spiked with LPS to perform O antigen specific detection of LPS from E. coli O157. To validate assay performance, we evaluated the biophysical interactions of LPS with lipid bilayers both in- and outside of a flow cell using fluorescence microscopy and fluorescently doped lipids. Our results indicate that membrane insertion allows for the qualitative and reliable identification of amphiphilic LPS in complex samples like beef homogenates. We also demonstrated that LPS-induced hole formation does not occur under the conditions of the membrane insertion assays. Together, these findings describe for the first time the serogroup-specific detection of amphiphilic LPS in complex samples using a membrane insertion assay, and highlight the importance of LPS molecular conformations in detection architectures

Haemorrhagic Colitis Associated with Enterohaemorrhagic \u3ci\u3eEscherichia coli\u3c/i\u3e O165:H25 Infection in a Yearling Feedlot Heifer

Introduction: Enterohaemorrhagic Escherichia coli (EHEC) cause haemorrhagic colitis and haemolytic uraemic syndrome in humans. Although EHEC infection typically results in haemorrhagic colitis in all ages of human patients, in cattle it is usually limited to 1- to 5-week-old nursing calves. Case Presentation: A 1-year-old feedlot beef heifer was moribund with neurological signs and bloody diarrhoea. At necropsy, the colonic mucosa contained multiple grossly visible haemorrhagic erosions, each measuring \u3c1 mm in diameter. Histologically, foci corresponding to the gross erosions had E. coli O165 antigen-positive bacterial rods adherent to the apical surfaces of degenerate and necrotic colonic mucosal epithelial cells in association with attaching and effacing lesions, and also within cytoplasmic vacuoles in some of these cells. An E. coli O165:H25 strain was isolated from the colonic mucosal tissue, and by microarray analysis was found to contain virulence genes corresponding to type III secretion system (T3SS) structure and regulation (cesD, cesT, escD, escF, escN/escV, escR, escT, ler, sepL, sepQ), T3SS effectors (espA, espB, espC, espD, espD, espF, espH, espJ, nleB, nleC, nleD, nleH, tir), serine proteases (eatA, espC, espP), Shiga toxin (stx2), EHEC-haemolysin (ehxA), and adhesins [intimin-ε (eae-ε), type 1 fimbria (fimA, fimB, fimH), type IV pili (pilA, pilB, pilC, pilM, pilP, pilQ) and non-fimbrial adhesin (efa1/lifA)]. Conclusion: To the best of our knowledge, this is the first report of disease in cattle associated with EHEC O165:H25 infection, the oldest bovine EHEC disease case with isolation of the pathogen and the first bovine case to demonstrate grossly evident, haemorrhagic, colonic mucosal erosions associated with EHEC infection

Predator water balance alters intraguild predation in a streamsidefood web

Previous work suggests that animal water balance can influence trophic interactions, with predators increasing their consumption of water-laden prey to meet water demands.But it is unclear how the need for water interacts with the need for energy to drive trophic interactions under shifting conditions. Using manipulative field experiments, we show that water balance influences the effects of top predators on prey with contrasting ratios of water and energy, altering the frequency of intraguild predation. Water-stressed top predators (large spiders) negatively affect water-laden basal prey (crickets), especially male prey with higher water content, whereas alleviation of water limitation causes top predators to switch to negatively affecting energy-rich midlevel predators (small spiders). Thus, the relative water and energy content of multiple prey, combined with the water demand of the top predator, influences trophic interactions in ways that can alter the strength of intraguild predation. These findings underscore the need for integration of multi resource approaches for understanding implications of global change for food webs

Haemorrhagic Colitis Associated with Enterohaemorrhagic \u3ci\u3eEscherichia coli\u3c/i\u3e O165:H25 Infection in a Yearling Feedlot Heifer

Introduction: Enterohaemorrhagic Escherichia coli (EHEC) cause haemorrhagic colitis and haemolytic uraemic syndrome in humans. Although EHEC infection typically results in haemorrhagic colitis in all ages of human patients, in cattle it is usually limited to 1- to 5-week-old nursing calves. Case Presentation: A 1-year-old feedlot beef heifer was moribund with neurological signs and bloody diarrhoea. At necropsy, the colonic mucosa contained multiple grossly visible haemorrhagic erosions, each measuring \u3c1 mm in diameter. Histologically, foci corresponding to the gross erosions had E. coli O165 antigen-positive bacterial rods adherent to the apical surfaces of degenerate and necrotic colonic mucosal epithelial cells in association with attaching and effacing lesions, and also within cytoplasmic vacuoles in some of these cells. An E. coli O165:H25 strain was isolated from the colonic mucosal tissue, and by microarray analysis was found to contain virulence genes corresponding to type III secretion system (T3SS) structure and regulation (cesD, cesT, escD, escF, escN/escV, escR, escT, ler, sepL, sepQ), T3SS effectors (espA, espB, espC, espD, espD, espF, espH, espJ, nleB, nleC, nleD, nleH, tir), serine proteases (eatA, espC, espP), Shiga toxin (stx2), EHEC-haemolysin (ehxA), and adhesins [intimin-ε (eae-ε), type 1 fimbria (fimA, fimB, fimH), type IV pili (pilA, pilB, pilC, pilM, pilP, pilQ) and non-fimbrial adhesin (efa1/lifA)]. Conclusion: To the best of our knowledge, this is the first report of disease in cattle associated with EHEC O165:H25 infection, the oldest bovine EHEC disease case with isolation of the pathogen and the first bovine case to demonstrate grossly evident, haemorrhagic, colonic mucosal erosions associated with EHEC infection

Gene Expression Patterns Specific to the Regenerating Limb of the Mexican Axolotl

Salamander limb regeneration is dependent upon tissue interactions that are local to the amputation site. Communication among limb epidermis, peripheral nerves, and mesenchyme coordinate cell migration, cell proliferation, and tissue patterning to generate a blastema, which will form missing limb structures. An outstanding question is how cross-talk between these tissues gives rise to the regeneration blastema. To identify genes associated with epidermis-nerve-mesenchymal interactions during limb regeneration, we examined histological and transcriptional changes during the first week following injury in the wound epidermis and subjacent cells between three injury types; 1) a flank wound on the side of the animal that will not regenerate a limb, 2) a denervated limb that will not regenerate a limb, and 3) an innervated limb that will regenerate a limb. Early, histological and transcriptional changes were similar between the injury types, presumably because a common wound-healing program is employed across anatomical locations. However, some transcripts were enriched in limbs compared to the flank and are associated with vertebrate limb development. Many of these genes were activated before blastema outgrowth and expressed in specific tissue types including the epidermis, peripheral nerve, and mesenchyme. We also identified a relatively small group of transcripts that were more highly expressed in innervated limbs versus denervated limbs. These transcripts encode for proteins involved in myelination of peripheral nerves, epidermal cell function, and proliferation of mesenchymal cells. Overall, our study identifies limb-specific and nerve-dependent genes that are upstream of regenerative growth, and thus promising candidates for the regulation of blastema formation

Natural Analogue Constraints on Europa's Non-ice surface Material

Non-icy material on the surface of Jupiter’s moon Europa is hypothesised to have originated from its subsurface ocean, and thus provide a record of ocean composition and habitability. The nature of this material is debated, but observations suggest that it comprises hydrated sulfate and chloride salts. Analogue spectroscopic studies have previously focused on single phase salts under controlled laboratory conditions. We investigated natural salts from perennially cold (<0 °C) hypersaline springs, and characterised their reflectance properties at 100 K, 253 K and 293 K. Despite similar major ion chemistry, these springs form mineralogically diverse deposits, which when measured at 100 K closely match reflectance spectra from Europa. In the most sulfate-rich samples, we find spectral features predicted from laboratory salts are obscured. Our data are consistent with sulfate-dominated europan non-icy material, and further, show that the emplacement of endogenic sulfates on Europa’s surface would not preclude a chloride-dominated ocean

Prevalence and Level of Enterohemorrhagic \u3ci\u3eEscherichia coli\u3c/i\u3e in Culled Dairy Cows at Harvest

The primary objective of this study was to determine the prevalence and level of enterohemorrhagic Escherichia coli (EHEC) O26, O45, O103, O111, O121, and O145 (collectively EHEC-6) plus EHEC O157 in fecal, hide, and preintervention carcass surface samples from culled dairy cows. Matched samples (n=300) were collected from 100 cows at harvest and tested by a culture-based method and two molecular methods: NeoSEEK STEC (NS) and Atlas STEC EG2 Combo. Both the culture and NS methods can be used to discriminate among the seven EHEC types (EHEC-7), from which the cumulative prevalence was inferred, whereas the Atlas method can discriminate only between EHEC O157 and non-O157 EHEC, without discrimination of the serogroup. The EHEC-7 prevalence in feces, hides, and carcass surfaces was 6.5, 15.6, and 1.0%, respectively, with the culture method and 25.9, 64.9, and 7.0%, respectively, with the NS method. With the Atlas method, the prevalence of non-O157 EHEC was 29.1, 38.3, and 28.0% and that of EHEC O157 was 29.1, 57.0, and 3.0% for feces, hides, and carcasses, respectively. Only two samples (a hide sample and a fecal sample) originating from different cows contained quantifiable EHEC. In both samples, the isolates were identified as EHEC O157, with 4.7 CFU/1,000 cm2 in the hide sample and 3.9 log CFU/g in the fecal sample. Moderate agreement was found between culture and NS results for detection of EHEC O26 (k=0.58,

A comparison of two methods of quantifying masticatory pressures developed under dentures with variable occlusal widths

Pressures developed during mastication with removable dental prostheses have beer quantified by two methods. This pilot study (1) compares the peak pressure method of pressure quantification with the integrated curve method of quantification and (2) continues the exploration of the effect of the width of the occlusal table on pressures developed under dentures. A set of specially designed experimental dentures was constructed for one individual. The mandibular experimental denture contained a series of pressure transducers by which masticatory pressures were recorded. These pressures were monitored between the denture base and the residual ridge tissues. Several interchangeable posterior occlusal segments, varying only in the width of the occlusal table, were fabricated for the opposing maxillary denture. Masticatory pressure and total ridge pressure were quantified by the integrated curve method and the peak pressure method. Both methods indicated a direct relationship between masticatory pressures produced and the width of the occlusal table. A similar direct relationship between total ridge pressure and occlusal width was suggested statistically by the integrated curve method, and graphically by both methods.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73368/1/j.1365-2842.1979.tb00407.x.pd

Integrating the Molecular Basis of Sustainability into General Chemistry through Systems Thinking

The flow of materials and energy through society is an integral but poorly visible element of global sustainability agendas such as the Planetary Boundaries Framework and the UN Sustainable Development Goals (UNSDG). Given that the primary activities of chemistry are to analyze, synthesize, and transform matter, the practice of chemistry has a great deal to contribute to sustainability science, which in turn should play an increasingly important role in reshaping the practice of chemistry. Success in integrating sustainability considerations into the practice of chemistry implies a substantial role for chemistry education to better equip students to address the sustainability of earth and societal systems. Building on the framework of the IUPAC Systems Thinking in Chemistry Education (STICE) project, we develop approaches to using systems thinking to educate students about the molecular basis of sustainability, to assist chemistry to contribute meaningfully and visibly toward the attainment of global sustainability agendas. A detailed exemplar shows how ubiquitous coverage in general chemistry courses of the Haber–Bosch process for the synthesis of ammonia could be extended using systems thinking to consider the complex interplay of this industrial process with scientific, societal, and environmental systems. Systems thinking tools such as systems thinking concept map extension (SOCME) visualizations assist in highlighting inputs, outputs, and societal consequences of this large-scale industrial process, including both intended and unintended alterations to the planetary cycle of nitrogenous compounds. Strategies for using systems thinking in chemistry education and addressing the challenges its use may bring to educators and students are discussed, and suggestions are offered for general chemistry instructors using systems thinking to educate about the molecular basis of sustainability