Regulation of Monokine Gene Expression: Prostaglandin E2 Suppresses Tumor Necrosis Factor but Not Interleukin‐1α or β‐mRNA and Cell‐Associated Bioactivity

Prostaglandin E2 (PGE2)‐mediated suppression of macrophage interleukin‐1α,β and tumor necrosis factor‐α synthesis was examined at the cellular and molecular levels. Treatment of lipopolysaccharide (LPS)‐stimulated adjuvant‐elicited murine macrophages with 5 × 10‐7M PGE2 caused a 70% reduction in cell‐associated TNF but had no suppressive effect on cell‐associated interleukln‐1 (IL‐1) activity. Consistent with this result, Northern blot and nuclear transcription analyses demonstrated suppression of TNF mRNA but PGE2 had no effect on IL‐1α and IL‐1β mRNA accumulation, as compared to LPS controls. Immunoperoxidase staining for cell‐associated TNFα, IL‐1α, and IL‐1β demonstrated that PGE2 suppressed TNF, but not IL‐1α or ‐β expression, supporting the bioassay data. These results imply that PGE2‐mediated regulation of IL‐1α,β and TNFα is quite distinct. Synthesis of TNF appears to be regulated at least at the level of transcription, whereas that for IL‐1α and ‐β is regulated post‐transcriptionally.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141223/1/jlb0416.pd

QUANTIFYING CRITICAL FEATURES OF UNDERWATER STROKE TECHNIQUE IN FREESTYLE SWIMMING

The purpose of this study was to establish methods for accurately quantifying the time of entry, catch and release in freestyle swimming. The methods allow ready data collection, digitising and analysis without recourse to expensive cameras and diglising equipment thereby enabling analysis by coaches as well as biomechanists. Interpolation procedures to improve the accuracy of estimating the time of occurrence of the events were developed

Centre of pressure, vertical ground reaction forces and neuromuscular responses of special-forces soldiers to 43km load carriage in the field

The primary purpose of this study was to examine lateral deviations in centre of pressure as a result of an extreme duration load carriage task, with particular focus on heel contact. Twenty (n=17 males, n=3 females) soldiers from a Special Operation Forces unit (body mass: 80.72±21.49kg; stature:178.25±8.75cm; age: 26±9yrs) underwent gait plantar pressure assessment and vertical jump testing before and after a 43km load carriage event (duration 817.02[32.66]min) carrying a total external load of 29.80 (1.05)kg. Vertical jump height decreased by 18.62%±16.85% (0.30±0.08m to 0.24±0.07m) p<.001. Loading peak and mid stance force minimum were significantly increased after load carriage (2.59±0.51BW vs. 2.81±0.61BW; p=.035; dGlass=0.44 and 1.28±0.40BW vs. 1.46±0.41BW; p=.015 dGlass=0.45, respectively) and increases in lateral centre of pressure displacement were observed as a result of the load carriage task 14.64±3.62mm to 16.97 ±3.94mm p<.029. In conclusion, load carriage instigated a decrease in neuromuscular function alongside increases in ground reaction forces associated with injury risk and centre of pressure changes associated with ankle sprain risk. Practitioners should consider that possible reduction in ankle stability remains even once the load had been removed, suggesting soldiers are still at increased risk of injury even once the load has been removed

Millimeter Wave Localization: Slow Light and Enhanced Absorption

We exploit millimeter wave technology to measure the reflection and transmission response of random dielectric media. Our samples are easily constructed from random stacks of identical, sub-wavelength quartz and Teflon wafers. The measurement allows us to observe the characteristic transmission resonances associated with localization. We show that these resonances give rise to enhanced attenuation even though the attenuation of homogeneous quartz and Teflon is quite low. We provide experimental evidence of disorder-induced slow light and superluminal group velocities, which, in contrast to photonic crystals, are not associated with any periodicity in the system. Furthermore, we observe localization even though the sample is only about four times the localization length, interpreting our data in terms of an effective cavity model. An algorithm for the retrieval of the internal parameters of random samples (localization length and average absorption rate) from the external measurements of the reflection and transmission coefficients is presented and applied to a particular random sample. The retrieved value of the absorption is in agreement with the directly measured value within the accuracy of the experiment.Comment: revised and expande

Identifying predictable foraging habitats for a wide-ranging marine predator using ensemble ecological niche models

Aim Ecological niche modelling can provide valuable insight into species' environmental preferences and aid the identification of key habitats for populations of conservation concern. Here, we integrate biologging, satellite remote-sensing and ensemble ecological niche models (EENMs) to identify predictable foraging habitats for a globally important population of the grey-headed albatross (GHA) Thalassarche chrysostoma. Location Bird Island, South Georgia; Southern Atlantic Ocean. Methods GPS and geolocation-immersion loggers were used to track at-sea movements and activity patterns of GHA over two breeding seasons (n = 55; brood-guard). Immersion frequency (landings per 10-min interval) was used to define foraging events. EENM combining Generalized Additive Models (GAM), MaxEnt, Random Forest (RF) and Boosted Regression Trees (BRT) identified the biophysical conditions characterizing the locations of foraging events, using time-matched oceanographic predictors (Sea Surface Temperature, SST; chlorophyll a, chl-a; thermal front frequency, TFreq; depth). Model performance was assessed through iterative cross-validation and extrapolative performance through cross-validation among years. Results Predictable foraging habitats identified by EENM spanned neritic ( 0.5 mg m−3) and frequent manifestation of mesoscale thermal fronts. Our results confirm previous indications that GHA exploit enhanced foraging opportunities associated with frontal systems and objectively identify the APFZ as a region of high foraging habitat suitability. Moreover, at the spatial and temporal scales investigated here, the performance of multi-model ensembles was superior to that of single-algorithm models, and cross-validation among years indicated reasonable extrapolative performance. Main conclusions EENM techniques are useful for integrating the predictions of several single-algorithm models, reducing potential bias and increasing confidence in predictions. Our analysis highlights the value of EENM for use with movement data in identifying at-sea habitats of wide-ranging marine predators, with clear implications for conservation and management

Rural livelihoods and mangrove degradation in south-west Madagascar: lime production as an emerging threat

Mangroves are heavily threatened globally, with fuelwood harvesting and charcoal production a growing threat in low-income nations. However, the socio-ecological dynamics of mangroves are poorly understood, especially the roles of poverty and wealth in shaping resource use. This is particularly the case with Madagascar's mangroves, which contribute 2% of global mangrove cover. We report on the use of and threats to mangroves in the Bay of Assassins in south-west Madagascar. We document the production of sokay, a sea-shell based lime produced in mangrove wood kilns and used as a render on houses to improve their durability. Lime rendered houses are considered a status symbol. Growth in the use of lime is related to a rise in income in some households, which is partly a result of the increased commodification of marine products such as octopus, seaweed and sea cucumber. These products have experienced rapid commercialization over the last decade, with fishers now supplying global markets. We also document evidence of the emergence of larger-scale lime production. The growth of lime production has major ramifications for mangrove cover. We have observed a worrying development in mangrove harvesting patterns tied to lime production, where mangrove ecosystems are cleared instead of selectively cut. We consider the implications of our findings for broader debates about the relationship between conservation, poverty and natural resource use. We highlight research priorities and discuss the policy implications of our research, especially the need for the integrated management of ecosystems.This research was funded through an Environment and Sustainability Grant from the Royal Geographical Society (with IBG)

Rapid tyrosine phosphorylation of neuronal proteins including tau and focal adhesion kinase in response to amyloid-beta peptide exposure: Involvement of src family protein kinases

The increased production of amyloid beta -peptide (A beta) in Alzheimer's disease is acknowledged to be a key pathogenic event. In this study, we examined the response of primary human and rat brain cortical cultures to A beta administration and found a marked increase in the tyrosine phosphorylation content of numerous neuronal proteins, including tau and putative microtubule-associated protein 2c (MAP2c). We also found that paired helical filaments of aggregated and hyperphosphorylated tau are tyrosine phosphorylated, indicating that changes in the phosphotyrosine content of cytoplasmic proteins in response to A beta are potentially an important process. Increased tyrosine phosphorylation of cytoskeletal and other neuronal proteins was specific to fibrillar A beta (25-35) and A beta (1-42). The tyrosine phosphorylation was blocked by addition of the Src family tyrosine kinase inhibitor 4-amino-5-( 4-chlorophenyl)- 7(t-butyl) pyrazol(3,4-D) pyramide (PP2) and the phosphatidylinositol 3-kinase inhibitor LY 294002. Tyrosine phosphorylation of tau and MAP2c was concomitant with an increase in the tyrosine phosphorylation and subsequent putative activation of the non-receptor kinase, focal adhesion kinase (FAK). Immunoprecipitation of Fyn, a member of the Src family, from A beta (25-35)-treated neurons showed an increased association of Fyn with FAK. A beta treatment of cells also stimulated the sustained activation of extracellular regulated kinase-2, which was blocked by addition of PP2 and LY 294002, suggesting that FAK/Fyn/PI3-kinase association is upstream of mitogen-activated protein (MAP) kinase signaling in A beta -treated neurons. This cascade of signaling events contains the earliest biochemical changes in neurons to be described in response to A beta exposure and may be critical for subsequent neurodegenerative changes

Syntaxin 16 is a master recruitment factor for cytokinesis

Recently it was shown that both recycling endosome and endosomal sorting complex required for transport (ESCRT) components are required for cytokinesis, in which they are believed to act in a sequential manner to bring about secondary ingression and abscission, respectively. However, it is not clear how either of these complexes is targeted to the midbody and whether their delivery is coordinated. The trafficking of membrane vesicles between different intracellular organelles involves the formation of soluble N-ethylmalei­mide–sensitive factor attachment protein receptor (SNARE) complexes. Although membrane traffic is known to play an important role in cytokinesis, the contribution and identity of intracellular SNAREs to cytokinesis remain unclear. Here we demonstrate that syntaxin 16 is a key regulator of cytokinesis, as it is required for recruitment of both recycling endosome–associated Exocyst and ESCRT machinery during late telophase, and therefore that these two distinct facets of cytokinesis are inextricably linked

Basking sharks and oceanographic fronts: quantifying associations in the north-east Atlantic

Understanding the mechanisms linking oceanographic processes and marine vertebrate habitat use is critical to effective management of populations of conservation concern. The basking shark Cetorhinus maximus has been shown to associate with oceanographic fronts – physical interfaces at the transitions between water masses – to exploit foraging opportunities resulting from aggregation of zooplankton. However, the scale, significance and variability of these observed associations have not yet been established. Here, we quantify the influence of mesoscale (10s – 100s km) frontal activity on habitat use over timescales of weeks to months. We use animal-mounted archival tracking with composite front mapping via Earth Observation (EO) remote sensing to provide an oceanographic context to individual shark movements. We investigate levels of association with fronts occurring over two spatio-temporal scales, (i) broad-scale seasonally persistent frontal zones and (ii) contemporaneous mesoscale thermal and chl-a fronts. Using random walk simulations and logistic regression within an iterative generalised linear mixed modelling (GLMM) framework, we find that seasonal front frequency is a significant predictor of shark presence. Temporally-matched oceanographic metrics also indicate that sharks demonstrate a preference for productive regions, and associate with contemporaneous thermal and chl-a fronts more frequently than could be expected at random. Moreover, we highlight the importance of cross-frontal temperature change and persistence, which appear to interact to affect the degree of prey aggregation along thermal fronts. These insights have clear implications for understanding the preferred habitats of basking sharks in the context of anthropogenic threat management and marine spatial planning in the northeast Atlantic