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Wildfire and cattle legacies on gradients of soil nitrogen underlie patterns of annual brome invasion
Human activities are increasing wildfires and livestock activity in arid ecosystems with potential implications for the spread of invasive grasses. The objective of this study was to test whether fire history and cattle activity alter soil resource gradients, thereby affecting patterns of Bromus rubens L. (red brome) invasion. Six paired burned and unburned transect lines (1-km long) were established in the northeast Mojave Desert along the boundaries of four independent wildfire scars. At 100-m transect increment points, we measured the distance to the two nearest cowpats, and two random points and measured the density, height, biomass, and seed production of red brome, soil moisture and inorganic nitrogen (N). Cattle activity was 29% greater along burned transects compared to unburned transects (P < 0.05). Red brome height, density, and seed production were 11–34% greater along burned transects than unburned transects (P < 0.05). Red brome height, biomass, density, and seed production were twofold to tenfold greater next to cowpats compared to random points (P < 0.05). Soils along burned transects and beneath cowpats had greater soil inorganic N (P < 0.05), which was positively correlated with red brome density, height, biomass, and seed production (R2 = 0.60–0.85, P < 0.0001). Transgenerational effects were evident as seeds from red brome next to cowpats had 27% higher germination than seeds collected from random points. Positive responses of red brome to increased inorganic N related to fire and cattle activity may contribute fine fuel infill that drives invasive grass-fire cycles in deserts.
Journal Article
Silence for the dead
\"\"Portis House emerged from the fog as we approached, showing itself slowly as a long, low shadow....\" In 1919, Kitty Weekes, pretty, resourceful, and on the run, falsifies her background to obtain a nursing position at Portis House, a remote hospital for soldiers left shell-shocked by the horrors of the Great War. Hiding the shame of their mental instability in what was once a magnificent private estate, the patients suffer from nervous attacks and tormenting dreams. But something more is going on at Portis House-its plaster is crumbling, its plumbing makes eerie noises, and strange breaths of cold waft through the empty rooms. It's known that the former occupants left abruptly, but where did they go? And why do the patients all seem to share the same nightmare, one so horrific that they dare not speak of it? Kitty finds a dangerous ally in Jack Yates, an inmate who may be a war hero, a madman or maybe both. But even as Kitty and Jack create a secret, intimate alliance to uncover the truth, disturbing revelations suggest the presence of powerful spectral forces. And when a medical catastrophe leaves them even more isolated, they must battle the menace on their own, caught in the heart of a mystery that could destroy them both\"-- Provided by publisher.
Book
Dual-Process Theories of Higher Cognition: Advancing the Debate
Dual-process and dual-system theories in both cognitive and social psychology have been subjected to a number of recently published criticisms. However, they have been attacked as a category, incorrectly assuming there is a generic version that applies to all. We identify and respond to 5 main lines of argument made by such critics. We agree that some of these arguments have force against some of the theories in the literature but believe them to be overstated. We argue that the dual-processing distinction is supported by much recent evidence in cognitive science. Our preferred theoretical approach is one in which rapid autonomous processes (Type 1) are assumed to yield default responses unless intervened on by distinctive higher order reasoning processes (Type 2). What defines the difference is that Type 2 processing supports hypothetical thinking and load heavily on working memory.
Journal Article
Megafire affects stream sediment flux and dissolved organic matter reactivity, but land use dominates nutrient dynamics in semiarid watersheds
Climate change is causing larger wildfires and more extreme precipitation events in many regions. As these ecological disturbances increasingly coincide, they alter lateral fluxes of sediment, organic matter, and nutrients. Here, we report the stream chemistry response of watersheds in a semiarid region of Utah (USA) that were affected by a megafire followed by an extreme precipitation event in October 2018. We analyzed daily to hourly water samples at 10 stream locations from before the storm event until three weeks after its conclusion for suspended sediment, solute and nutrient concentrations, water isotopes, and dissolved organic matter concentration, optical properties, and reactivity. The megafire caused a ~2,000-fold increase in sediment flux and a ~6,000-fold increase in particulate carbon and nitrogen flux over the course of the storm. Unexpectedly, dissolved organic carbon (DOC) concentration was 2.1-fold higher in burned watersheds, despite the decreased organic matter from the fire. DOC from burned watersheds was 1.3-fold more biodegradable and 2.0-fold more photodegradable than in unburned watersheds based on 28-day dark and light incubations. Regardless of burn status, nutrient concentrations were higher in watersheds with greater urban and agricultural land use. Likewise, human land use had a greater effect than megafire on apparent hydrological residence time, with rapid stormwater signals in urban and agricultural areas but a gradual stormwater pulse in areas without direct human influence. These findings highlight how megafires and intense rainfall increase short-term particulate flux and alter organic matter concentration and characteristics. However, in contrast with previous research, which has largely focused on burned-unburned comparisons in pristine watersheds, we found that direct human influence exerted a primary control on nutrient status. Reducing anthropogenic nutrient sources could therefore increase socioecological resilience of surface water networks to changing wildfire regimes.
Journal Article
Sleep restriction increases the neuronal response to unhealthy food in normal-weight individuals
Context:
Sleep restriction alters responses to food. However, the underlying neural mechanisms for this effect are not well understood.
Objective:
The purpose of this study was to determine whether there is a neural system that is preferentially activated in response to unhealthy compared with healthy foods.
Participants:
Twenty-five normal-weight individuals, who normally slept 7–9 h per night, completed both phases of this randomized controlled study.
Intervention:
Each participant was tested after a period of five nights of either 4 or 9 h in bed. Functional magnetic resonance imaging (fMRI) was performed in the fasted state, presenting healthy and unhealthy food stimuli and objects in a block design. Neuronal responses to unhealthy, relative to healthy food stimuli after each sleep period were assessed and compared.
Results:
After a period of restricted sleep, viewing unhealthy foods led to greater activation in the superior and middle temporal gyri, middle and superior frontal gyri, left inferior parietal lobule, orbitofrontal cortex, and right insula compared with healthy foods. These same stimuli presented after a period of habitual sleep did not produce marked activity patterns specific to unhealthy foods. Further, food intake during restricted sleep increased in association with a relative decrease in brain oxygenation level-dependent (BOLD) activity observed in the right insula.
Conclusion:
This inverse relationship between insula activity and food intake and enhanced activation in brain reward and food-sensitive centers in response to unhealthy foods provides a model of neuronal mechanisms relating short sleep duration to obesity.
Journal Article
The haunting of Maddy Clare
\"In 1920s England, a young woman of limited means and even less experience confronts the ghost of a mysterious serving maid.... Sarah Piper's lonely threadbare existence changes when her temporary agency sends her to assist a ghost hunter. Alistair Gellis--rich, handsome, scarred by World War I, and obsessed by ghosts--has been summoned to investigate the spirit of the nineteen-year-old maid Maddy Clare, who is said to haunt the barn where she committed suicide. Maddy hated men in life, and she will not speak to them in death. But Sarah is unprepared to go alone into a haunted barn looking for the truth. She's even less prepared for the arrival of Alistair's associate, rough, unsettling Matthew Ryder, also a veteran of the trenches, whose scars go deeper than Sarah can reach. Soon, Sarah is caught up in a desperate struggle. For Maddy's ghost is no hoax--she's real, she's angry, and she has powers that defy all reason. Can Sarah and Matthew discover who Maddy was, where she came from, and what is driving her desire for vengeance...before she destroys them all?\"-- Provided by publisher.
Book
Manganese superoxide dismutase deficiency triggers mitochondrial uncoupling and the Warburg effect
Manganese superoxide dismutase (MnSOD) is a mitochondrially localized primary antioxidant enzyme, known to be essential for the survival of aerobic life and to have important roles in tumorigenesis. Here, we show that MnSOD deficiency in skin tissues of MnSOD-heterozygous knockout (
Sod2
+/−
) mice leads to increased expresson of uncoupling proteins (UCPs). When MnSOD is deficient, superoxide radical and its resulting reactive oxygen species (ROS) activate ligand binding to peroxisome proliferator-activated receptor alpha (PPARα), suggesting that the activation of PPARα signaling is a major mechanism underlying MnSOD-dependent UCPs expression that consequently triggers the PI3K/Akt/mTOR pathway, leading to increased aerobic glycolysis. Knockdown of UCPs and mTOR suppresses lactate production and increases ATP levels, suggesting that UCPs contribute to increased glycolysis. These results highlight the existence of a free radical-mediated mechanism that activates mitochondria uncoupling to reduce ROS production, which precedes the glycolytic adaptation described as the Warburg Effect.
Journal Article