Cast Stone has been developed to immobilize a fraction of radioactive waste at the Hanford Site; however, constituents of potential concern (COPCs) can be released when in contact with water during ...disposal. Herein, a representative mineral and parameter set for geochemical speciation modeling was developed for Cast Stone aged in inert and oxic environments, to simulate leaching concentrations of major and trace constituents. The geochemical speciation model was verified using a monolithic diffusion model in conjunction with independent monolithic diffusion test results. Eskolaite (Cr2O3) was confirmed as the dominant mineral retaining Cr in Cast Stone doped with 0.1 or 0.2 wt % Cr. The immobilization of Tc as a primary COPC in Cast Stone was evaluated, and the redox states of porewater within monolithic Cast Stone indicated by Cr are insufficient for the reduction of Tc. However, redox states provided by blast furnace slag (BFS) within the interior of Cast Stone are capable of reducing Tc for immobilization, with the immobilization reaction rate postulated to be controlled by the diffusive migration of soluble Tc in porewater to the surface of reducing BFS particles. Aging in oxic conditions increased the flux of Cr and Tc from monolithic Cast Stone.
For food-caching animals inhabiting environments with strong seasonal variation, harsh winter conditions may limit access to naturally available food and favour the evolution of enhanced spatial ...memory. Spatial memory enables animals to remember the locations of food caches for overwinter survival, therefore animals in harsher conditions may benefit more from more accurate spatial memory than conspecifics living under relatively mild conditions. Despite numerous laboratory studies lending indirect support to the hypothesis that a harsh environment favours the evolution of spatial memory, there is no direct evidence showing fitness consequences of variation in spatial memory. As a step towards evaluating this hypothesis in natural populations, we established spatial arrays of programmable bird feeders equipped with radio frequency identification technology (RFID) to test for individual variation in spatial memory in food-caching mountain chickadees, Poecile gambeli, at two elevations differing in winter climate severity. Individuals could only access food at a single rewarding feeder within an array of eight, and each individual had to learn the location of their unique rewarding feeder. Birds at higher elevations visited the arrays significantly more frequently than birds at lower elevations, suggesting more intense food caching. They also performed better at locating their rewarding feeder than birds from lower elevations. Individuals showing better performance participated in more overall trials, suggesting a link between food-caching propensity and memory performance, but higher overall levels of activity within each array yielded less accurate memory performance. Finally, rotating the arrays showed that birds relied specifically on spatial memory in order to locate their rewarding feeder. To our knowledge, this is the first explicit test of spatial memory performance in food-caching birds under natural conditions. Our results corroborate earlier laboratory-based work showing large individual variation in spatial memory performance and lay the groundwork for future investigation into the fitness consequences of individual variation and the evolution of spatial memory.
•Harsh winters may favour the evolution of enhanced spatial memory in resident birds.•We tested spatial memory in chickadees from different elevations with radio frequency identification technology.•High-elevation birds outperformed low-elevation birds in a spatial memory task.•This is the first test of spatial memory variation in a food-caching bird in the wild.
Phenotypic variation may influence social structure if animals associate nonrandomly based on phenotypic traits. For animals that rely on cognition for survival, variation in cognitive ability may ...also affect social structure. Individuals with worse cognitive abilities could benefit from preferentially associating with conspecifics with better cognition, from being more gregarious, or both, allowing them access to resources. Climatic conditions influence resource availability, which may also affect the relative benefits of assortment or gregariousness, resulting in spatiotemporal variation of social patterns. Using 5 years of data, we investigated assortment by spatial cognitive ability and associations between sociality and spatial cognition in food-caching mountain chickadees,
Poecile gambeli
, inhabiting harsher environments at higher elevations and milder environments at lower elevations. Elevation environments differ in overwinter severity and in the harshest winter, high elevation chickadees with better spatial learning and memory abilities were less gregarious and showed lower social differentiation (or choosiness) than those with worse spatial learning and memory abilities but did not assort based on these traits. In two other seasons, including the second harshest winter, high elevation chickadees that were less cognitively flexible showed more social differentiation than those that were more cognitively flexible. In these two seasons alone, chickadees negatively assorted by spatial learning and memory performance. Chickadees from low elevations only demonstrated negative assortment in the second harshest winter. All other results were nonsignificant, suggesting that overall, individual spatial cognitive abilities or those of their associates have little influence on social preferences.
Significance statement
We showed that under certain environmental conditions, social behavior may be related to spatial cognitive abilities in mountain chickadees that rely heavily on spatial cognition for overwinter survival, but that overall, cognition does not appear to influence social behavior. In the few years that patterns were present, they fit three trends: 1) chickadees with worse spatial cognitive abilities were more gregarious; 2) chickadees with worse spatial cognitive abilities were choosier; and/or 3) chickadees had stronger associations with social partners that had spatial cognitive abilities that differed from their own and weaker associations with those of similar cognitive abilities. While it is unclear under which specific circumstances these patterns emerge, they coincided with extreme snowfall, suggesting that individuals with worse spatial cognition alter their social behavior to buffer against their relatively greater risk of starvation under extenuating circumstances.
Animals inhabiting montane gradients experience varying winter climates that may result in differential selection on survivalrelated traits. Higher elevations in temperate climates are characterized ...by harsher winters with greater and longer-lasting snow cover compared to lower elevations, potentially leading to stronger selection for traits that improve fitness under these harsher conditions. For food-caching mountain chickadees, Poecile gambeli, inhabiting harsh high elevation environments, individual variation in spatial cognitive abilities related to cache retrieval is associated with significant differences in overwinter survival. Compared to lower elevations, stronger predicted selection on traits needed for overwinter survival at higher elevations can be expected to result in higher adult annual survival despite harsher environmental conditions, indicating that individuals that survive their first winter are better suited to survive similar subsequent selection events. Here, we used a Bayesian hierarchical Cormack-Jolly-Seber (CJS) model to estimate and compare survival of adult mountain chickadees at higher and lower elevations over 3 years. We showed that adult survival was consistently higher at higher elevations despite much harsher environmental conditions, supporting our hypothesis that selection on overwinter survival-related traits (such as spatial cognition) is stronger at our high elevation study area than at lower elevations.
Objectives: To determine the prevalence and predictors of unnecessary drug use at hospital discharge in frail elderly patients.
Design: Cross‐sectional.
Setting: Eleven Veterans Affairs Medical ...Centers.
Participants: Three hundred eighty‐four frail older patients from the Geriatric Evaluation and Management Drug Study.
Measurements: Assessment of unnecessary drug use was determined by the consensus of a clinical pharmacist and physician pair applying the Medication Appropriateness Index to each regularly scheduled medication at hospital discharge. Those drugs that received an inappropriate rating for indication, efficacy, or therapeutic duplication were defined as unnecessary.
Results: Forty‐four percent of patients had at least one unnecessary drug, with the most common reason being lack of indication. The most commonly prescribed unnecessary drug classes were gastrointestinal, central nervous system, and therapeutic nutrients/minerals. Factors associated (P<.05) with unnecessary drug use included hypertension (adjusted odds ratio (AOR)=0.61, 95% confidence interval (CI)=0.38–0.96), multiple prescribers (AOR=3.35, 95% CI=1.16–9.68), and nine or more medications (AOR=2.24, 95% CI=1.25–3.99).
Conclusion: A high prevalence of unnecessary drug use at discharge was found in frail hospitalized elderly patients. Additional studies are needed to identify predictors and prevalence of unnecessary drug use in nonveteran populations so that interventions can be designed to reduce the problem.
A respiratory therapist-driven weaning protocol incorporating daily screens, spontaneous breathing trials (SBT), and prompts to caregivers has been associated with superior outcomes in mechanically ...ventilated medical patients. To determine the effectiveness of this approach in neurosurgical (NSY) patients, we conducted a randomized controlled trial involving 100 patients over a 14-mo period. All had daily screens of weaning parameters. If these were passed, a 2-h SBT was performed in the Intervention group. Study physicians communicated positive SBT results, and the decision to extubate was made by the primary NSY team. Patients in the Intervention (n = 49) and Control (n = 51) groups had similar demographic characteristics, illness severity, and neurologic injuries. Among all patients, 87 (45 in the Control and 42 in the Intervention group) passed at least one daily screen. Forty (82%) patients in the Intervention group passed SBT, but a median of 2 d passed before attempted extubation, primarily because of concerns about the patient's sensorium (84%). Of 167 successful SBT, 126 (75%) did not lead to attempted extubation on the same day. The median time of mechanical ventilation was 6 d in both study groups, and there were no differences in outcomes. Overall complications included death (36%), reintubation (16%), and pneumonia (9%). Tracheostomies were created in 29% of patients. Multivariate analysis showed that Glasgow Coma Scale (GCS) score (p < 0.0001) and partial pressure of arterial oxygen/fraction of inspired oxygen ratio (p < 0.0001) were associated with extubation success. The odds of successful extubation increased by 39% with each GCS score increment. A GCS score > or = 8 at extubation was associated with success in 75% of cases, versus 33% for a GCS score < 8 (p < 0.0001). Implementation of a weaning protocol based on traditional respiratory physiologic parameters had practical limitations in NSY patients, owing to concerns about neurologic impairment. Whether protocols combining respiratory parameters with neurologic measures lead to superior outcomes in this population requires further investigation.
The South African coastline has been invaded by numerous alien species. Rare pre-invasion (1980) and post-invasion datasets (2001 and 2012) exist for Marcus Island, a small land-tied island in ...Saldanha Bay, South Africa. These snapshot datasets of the island's intertidal invertebrate community were complemented with monitoring across seasons, from 2014 to 2016. Invertebrate communities were compared among the summers of 1980, 2001, 2012, 2014, 2015 and 2016 to assess interannual differences, while invertebrates and algae were monitored quarter-annually to assess seasonal changes. In addition, the population dynamics of the alien mussel Mytilus galloprovincialis were monitored. Differences in invertebrate communities between consecutive summers were significant but much smaller than changes induced by the arrival of alien species. Invertebrate and seaweed communities differed among years and shore zones but not among seasons, whereas species diversity differed among years, seasons and shore zones, with zones having the strongest influence. The invasion by M. galloprovincialis, and ensuing spatial and temporal variability in its recruitment, emerged as the most important factor influencing community composition, overshadowing interannual and seasonal changes. This work highlights that the impacts of alien species can be distinguished from natural variability by combining long-term monitoring with surveys at finer temporal scales. This is an important step in extending our understanding of the impacts of marine alien species.
Background and purpose: M 1 muscarinic ACh receptors (mAChRs) represent an attractive drug target for the treatment of cognitive deficits associated with diseases such as Alzheimer's disease and ...schizophrenia. However, the discovery of subtype‐selective mAChR agonists has been hampered by the high degree of conservation of the orthosteric ACh‐binding site among mAChR subtypes. The advent of functional screening assays has enabled the identification of agonists such as AC‐42 (4‐ n ‐butyl‐1‐4‐(2‐methylphenyl)‐4‐oxo‐1‐butyl‐piperidine), which bind to an allosteric site and selectively activate the M 1 mAChR subtype. However, studies with this compound have been limited to recombinantly expressed mAChRs. Experimental approach: In this study, we have compared the pharmacological profile of AC‐42 and a close structural analogue, 77‐LH‐28‐1 (1‐3‐(4‐butyl‐1‐piperidinyl)propyl‐3,4‐dihydro‐2(1 H )‐quinolinone) at human recombinant, and rat native, mAChRs by calcium mobilization, inositol phosphate accumulation and both in vitro and in vivo electrophysiology. Key results: Calcium mobilization and inositol phosphate accumulation assays revealed that both AC‐42 and 77‐LH‐28‐1 display high selectivity to activate the M 1 mAChR over other mAChR subtypes. Furthermore, 77‐LH‐28‐1, but not AC‐42, acted as an agonist at rat hippocampal M 1 receptors, as demonstrated by its ability to increase cell firing and initiate gamma frequency network oscillations. Finally, 77‐LH‐28‐1 stimulated cell firing in the rat hippocampus in vivo following subcutaneous administration. Conclusions and implications: These data suggest that 77‐LH‐28‐1 is a potent, selective, bioavailable and brain‐penetrant agonist at the M 1 mAChR and therefore that it represents a better tool than AC‐42, with which to study the pharmacology of the M 1 mAChR. British Journal of Pharmacology (2008) 154 , 1104–1115; doi: 10.1038/bjp.2008.152 ; published online 5 May 2008
HLA-G is a non-classical human leukocyte antigen expressed primarily in fetal tissues at the maternal–fetal interface. This expression pattern is unique among HLA genes and suggests that HLA-G may be ...involved in interactions that are critical in establishing and/or maintaining pregnancy. To evaluate the role of polymorphisms at this locus in maternal–fetal interactions, 113 couples with unexplained recurrent miscarriage were genotyped for seven polymorphisms that define 12 HLA-G alleles. Logistic regression analysis was used to assess whether HLA-G genotypes were associated with an increased risk for a subsequent miscarriage. The presence of an HLA-G*0104 or HLA-G*0105N allele in either partner was significantly associated with an increased risk for miscarriage, after adjustment for maternal age, number of previous miscarriages, history of a previous liveborn, and treatment with paternal mononuclear cells. The *0104 and *0105N alleles are defined by polymorphisms in the α-2 domain and encode protein variants that are present only in the full-length HLA-G1 protein. The significant genotype-specific risk in this population suggests that allelic variation in the α-2 domain of the HLA-G1 isoforms contributes to recurrent miscarriage.
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