68 research outputs found
The Prairie Post Quarterly Newsletter of the High Plains Regional Climate Center- January 2019
Inside this issue:
Message from the director........................................1
Staff spotlight...........................1
Year in review............................2
Drought THIRA toolkit...........3
Product highlight....................4
Update on regional climate conditions..................................4
Other HPRCC news.................5
Recent and upcoming travel and activities.............................
The Prairie Post Quarterly Newsletter of the High Plains Regional Climate Center- January 2019
Inside this issue:
Message from the director........................................1
Staff spotlight...........................1
Year in review............................2
Drought THIRA toolkit...........3
Product highlight....................4
Update on regional climate conditions..................................4
Other HPRCC news.................5
Recent and upcoming travel and activities.............................
Data from: Artificial light at night alters trophic interactions of intertidal invertebrates
Despite being globally widespread in coastal regions, the impacts of light pollution on intertidal ecosystems has received little attention. Intertidal species exhibit many night-time-dependent ecological strategies, including feeding, reproduction, orientation and predator avoidance, which are likely negatively affected by shifting light regimes, as has been observed in terrestrial and aquatic taxa.
Coastal lighting may shape intertidal communities through its influence on the nocturnal foraging activity of dogwhelks (Nucella lapillus), a widespread predatory mollusc that structures biodiversity in temperate rocky shores. In the laboratory, we investigated whether the basal and foraging activity of this predator was affected by exposure to night-time lighting both in the presence and absence of olfactory predator cues (Carcinus maenas, common shore crab).
Assessments of dogwhelks’ behavioural responses to night-time white LED lighting were performed on individuals that had been acclimated to night-time white LED lighting conditions for 16 days and individuals that had not previously been exposed to artificial light at night.
Dogwhelks acclimated to night-time lighting exhibited natural refuge-seeking behaviour less often compared to control animals, but were more likely to respond to and handle prey irrespective of whether olfactory predator cues were present. These responses suggest night-time lighting likely increased the energetic demand of dogwhelks through stress, encouraging foraging whenever food was available, regardless of potential danger. Contrastingly, whelks not acclimated under night-time lighting were more likely to respond to the presence of prey under artificial light at night when olfactory predator cues were present, indicating an opportunistic shift towards the use of visual instead of olfactory cues in risk evaluation.
These results demonstrate that artificial night-time lighting influences the behaviour of intertidal fauna such that the balance of interspecific interactions involved in community structuring may be affected
Enablers, markers, and aspects of quality innovative placements across distance: insights from a co-operative inquiry
Internationally, COVID-19 has forced educational reform and disrupted already strained social work field education systems. This inquiry began pre-pandemic, responding to placement scarcity, which was only exacerbated by the pandemic as agencies migrated to online service delivery and universities responded to sudden placement cancellations. Educators found themselves navigating two interlinked global trends: 1) workplace learning that was changing radically; and 2) the immediate need to identify and develop placement opportunities. This article presents themes from a co-operative inquiry that interrogated four innovative international placement scenarios from Australia, Canada, Ireland, and New Zealand, highlighting enablers, markers, and aspects of quality learning. The four exemplars evidence the pedagogical challenges and opportunities presented by placement innovation and online learning. These placements reveal how tensions regarding placement scarcity, rapid placement innovation, and the concurrent need to mitigate risk while preserving placement quality were managed. The authors propose that creativity and innovation guided by well-articulated educational principles, learning outcomes, and pedagogical practices, promote the construction of quality placements that transcend potential risks. The challenge moving forward is upholding contemporary approaches to placement teaching and learning that ensure social work students’ acquisition of professional knowledge, values and skills that are necessary for practice
Upper Albian OAE 1D Event in the Chihuahua Trough, New Mexico, U.S.A.
Oceanic anoxic events are clues to ocean processes and are correlation datums. In North America only OAE 1a and 2 are well documented. Based on a low-resolution sampling program, a multi-proxy geochemical approach constrained by a biostratigraphic framework was utilized to identify OAE 1d in the upper part of the upper Albian Mesilla Valley Formation near El Paso, Texas. Chronostratigraphic and biostratigraphic evidence indicate that the OAE 1d event in the Mesilla Valley section is located in the lower part of the upper Albian–Cenomanian Ovoidinium verrucosum zone, which correlates with the uppermost Albian Parathalmanninella appenninica and Stoliczkaia dispar zones. The chronostratigraphic age of the geochemical event in the Mesilla Valley Formation is uppermost Albian (97.39–97.30 Ma). The classic geochemical signatures for OAEs are enriched total organic carbon (TOC) concentrations and coupled positive δ13C excursions. OAE 1d at this location records TOC values ranging from 0.25 to 0.69 wt.% throughout the Mesilla Valley Formation, where TOC increases during the OAE (21.0–40.0 m) to more than 0.40 wt.%. Interestingly, the organic matter in the Mesilla Valley is dominantly type III, which indicates a pervasive terrigenous source. Although marine organic matter is abundant from the base into the middle of the proposed OAE interval, it is progressively replaced by terrestrial material above the OAE section during progradation. The δ13Corganic values record a positive δ13C shift of +1.6‰ from −26.41 to −24.80‰ across the stratigraphic interval from 21.0 to 40.0 m, which correlates with OAE 1d. Mn and Fe geochemistry suggest the depositional conditions of the Mesilla Valley Formation were dominated by anoxic and possibly Fe-rich bottom waters, specifically during the time period associated with the OAE 1d event. This interpretation is supported by the presence of Fe enrichment recorded by FeTotal/Al and FeHighly Reactive/FeT with the lack of Fepyrite/FeHighly Reactive associated with Mn depletion
Neuroexcitatory effects of morphine-3-glucuronide are dependent on Toll-like receptor 4 signaling
<p>Abstract</p> <p>Background</p> <p>Multiple adverse events are associated with the use of morphine for the treatment of chronic non-cancer pain, including opioid-induced hyperalgesia (OIH). Mechanisms of OIH are independent of opioid tolerance and may involve the morphine metabolite morphine-3-glucuronide (M3G). M3G exhibits limited affinity for opioid receptors and no analgesic effect. Previous reports suggest that M3G can act via the Toll-like receptor 4 (TLR4)/myeloid differentiation protein-2 (MD-2) heterodimer in the central nervous system to elicit pain.</p> <p>Methods</p> <p>Immunoblot and immunocytochemistry methods were used to characterize the protein expression of TLR4 present in lumbar dorsal root ganglion (DRG). Using <it>in vitro</it> intracellular calcium and current clamp techniques, we determined whether TLR4 activation as elicited by the prototypical agonists of TLR4, lipopolysaccharide (LPS) and M3G, contributed to changes in intracellular calcium and increased excitation. Rodents were also injected with M3G to determine the degree to which M3G-induced tactile hyperalgesia could be diminished using either a small molecule inhibitor of the MD-2/TLR4 complex in rats or TLR4 knockout mice. Whole cell voltage-clamp recordings were made from small- and medium-diameter DRG neurons (25 μm < DRG diameter <45 μm) for both control and M3G-treated neurons to determine the potential influence on voltage-gated sodium channels (NaVs).</p> <p>Results</p> <p>We observed that TLR4 immunoreactivity was present in peptidergic and non-peptidergic sensory neurons in the DRG. Non-neuronal cells in the DRG lacked evidence of TLR4 expression. Approximately 15% of assayed small- and medium-diameter sensory neurons exhibited a change in intracellular calcium following LPS administration. Both nociceptive and non-nociceptive neurons were observed to respond, and approximately 40% of these cells were capsaicin-insensitive. Increased excitability observed in sensory neurons following LPS or M3G could be eliminated using Compound 15, a small molecule inhibitor of the TLR4/MD-2 complex. Likewise, systemic injection of M3G induced rapid tactile, but not thermal, nociceptive behavioral changes in the rat, which were prevented by pre-treating animals with Compound 15. Unlike TLR4 wild-type mice, TLR4 knockout mice did not exhibit M3G-induced hyperalgesia. As abnormal pain sensitivity is often associated with NaVs, we predicted that M3G acting via the MD-2/TLR4 complex may affect the density and gating of NaVs in sensory neurons. We show that M3G increases tetrodotoxin-sensitive and tetrodotoxin-resistant (NaV1.9) current densities.</p> <p>Conclusions</p> <p>These outcomes provide evidence that M3G may play a role in OIH via the TLR4/MD-2 heterodimer complex and biophysical properties of tetrodotoxin-sensitive and tetrodotoxin-resistant NaV currents.</p
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