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Certain species of parasites have the apparent ability to alter the behaviour of their host in order to facilitate the completion of their own life cycle. While documented in hairworms (phylum Nematomorpha), the ability for mermithid parasites (from the sister phylum Nematoda) to force hosts to enter water remains more enigmatic. Here, we present the first experimental evidence in a laboratory setting that an insect which normally never enters open water (the European earwig Forficula auricularia) will readily enter the water when infected with a mermithid nematode (Mermis nigrescens). Only adult mermithids appear capable of inducing this polarising shift in behaviour, with mermithid length being a very strong predictor of whether their host enters water. However, mermithid length was only weakly associated with how long it took an earwig to enter water following the beginning of a trial. Considering the evidence presented here and its alignment with a proteomic investigation on the same host–parasite system, this study provides strong evidence for adaptive behavioural manipulation and a foundational system for further behavioural and mechanistic exploration.
Increasing the number of quantum bits while preserving precise control of their quantum electronic properties is a significant challenge in materials design for the development of semiconductor quantum computing devices. Semiconductor heterostructures can host multiple quantum dots that are electrostatically defined by voltages applied to an array of metallic nanoelectrodes. The structural distortion of multiple-quantum-dot devices due to elastic stress associated with the electrodes has been difficult to predict because of the large micrometer-scale overall sizes of the devices, the complex spatial arrangement of the electrodes, and the sensitive dependence of the magnitude and spatial variation of the stress on processing conditions. Synchrotron X-ray nanobeam Bragg diffraction studies of a GaAs/AlGaAs heterostructure reveal the magnitude and nanoscale variation of these distortions. Investigations of individual linear electrodes reveal lattice tilts consistent with a 28-MPa compressive residual stress in the electrodes. The angular magnitude of the tilts varies by up to 20% over distances of less than 200 nm along the length of the electrodes, consistent with heterogeneity in the metal residual stress. A similar variation of the crystal tilt is observed in multiple-quantum-dot devices, due to a combination of the variation of the stress and the complex electrode arrangement. The heterogeneity in particular can lead to significant challenges in the scaling of multiple-quantum-dot devices due to differences between the charging energies of dots and uncertainty in the potential energy landscape. Alternatively, if incorporated in design, stress presents a new degree of freedom in device fabrication.
Optical SETI at Lick Observatory is characterized by its robust approach to initial detections. Our three-detector system has distinguished itself by successful rejection of nearly all false positive signals. We present observational progress, discuss use of data analysis procedures such as FFTs and analysis of double coincidences, and mention plans to upgrade our instrumentation.
Evolution of cold dry snow and firn plays important roles in glaciology; however, the physical formulation of a densification law is still an active research topic. We forced eight firn-densification models and one seasonal-snow model in six different experiments by imposing step changes in temperature and accumulation-rate boundary conditions; all of the boundary conditions were chosen to simulate firn densification in cold, dry environments. While the intended application of the participating models varies, they are describing the same physical system and should in principle yield the same solutions. The firn models all produce plausible depth-density profiles, but the model outputs in both steady state and transient modes differ for quantities that are of interest in ice core and altimetry research. These differences demonstrate that firn-densification models are incorrectly or incompletely representing physical processes. We quantitatively characterize the differences among the results from the various models. For example, we find depth-integrated porosity is unlikely to be inferred with confidence from a firn model to better than 2 m in steady state at a specific site with known accumulation rate and temperature. Firn Model Intercomparison Experiment can provide a benchmark of results for future models, provide a basis to quantify model uncertainties and guide future directions of firn-densification modeling.
Nursing home residents are at risk for acquiring and transmitting MDROs. A serial point-prevalence study of 605 residents in 3 facilities using random sampling found MDRO colonization in 45% of residents: methicillin-resistant Staphylococcus aureus (MRSA, 26%); extended-spectrum β-lactamase–producing Enterobacteriaceae (ESBL, 17%); vancomycin-resistant Enterococcus spp. (VRE, 16%); carbapenem-resistant Enterobacteriaceae (CRE, 1%). MDRO colonization was associated with history of MDRO, care needs, incontinence, and catheters.
Psychological interventions may be beneficial in bipolar disorder.
To evaluate the efficacy of psychological interventions for adults with
A systematic review of randomised controlled trials was conducted.
Outcomes were meta-analysed using RevMan and confidence assessed using
the GRADE method.
We included 55 trials with 6010 participants. Moderate-quality evidence
associated individual psychological interventions with reduced relapses
at post-treatment (risk ratio (RR) = 0.66, 95% CI 0.48–0.92) and
follow-up (RR = 0.74, 95% CI 0.63–0.87), and collaborative care with a
reduction in hospital admissions (RR =0.68, 95% CI 0.49–0.94).
Low-quality evidence associated group interventions with fewer depression
relapses at post-treatment and follow-up, and family psychoeducation with
reduced symptoms of depression and mania.
There is evidence that psychological interventions are effective for
people with bipolar disorder. Much of the evidence was of low or very low
quality thereby limiting our conclusions. Further research should
identify the most effective (and cost-effective) interventions for each
phase of this disorder.
Standard estimates of the impact of Clostridium difficile infections (CDI) on inpatient lengths of stay (LOS) may overstate inpatient care costs attributable to CDI. In this study, we used multistate modeling (MSM) of CDI timing to reduce bias in estimates of excess LOS.
A retrospective cohort study of all hospitalizations at any of 120 acute care facilities within the US Department of Veterans Affairs (VA) between 2005 and 2012 was conducted. We estimated the excess LOS attributable to CDI using an MSM to address time-dependent bias. Bootstrapping was used to generate 95% confidence intervals (CI). These estimates were compared to unadjusted differences in mean LOS for hospitalizations with and without CDI.
During the study period, there were 3.96 million hospitalizations and 43,540 CDIs. A comparison of unadjusted means suggested an excess LOS of 14.0 days (19.4 vs 5.4 days). In contrast, the MSM estimated an attributable LOS of only 2.27 days (95% CI, 2.14–2.40). The excess LOS for mild-to-moderate CDI was 0.75 days (95% CI, 0.59–0.89), and for severe CDI, it was 4.11 days (95% CI, 3.90–4.32). Substantial variation across the Veteran Integrated Services Networks (VISN) was observed.
CDI significantly contributes to LOS, but the magnitude of its estimated impact is smaller when methods are used that account for the time-varying nature of infection. The greatest impact on LOS occurred among patients with severe CDI. Significant geographic variability was observed. MSM is a useful tool for obtaining more accurate estimates of the inpatient care costs of CDI.
Infect. Control Hosp. Epidemiol. 2015;36(9):1024–1030
Accurate sea-level reconstruction is critical in understanding the drivers of coastal evolution. Inliers of shallow marine limestone and aeolianite are exposed as zeugen (carbonate-capped erosional remnants) on the southern coast of the Arabian/Persian Gulf. These have generally been accepted as evidence of a eustatically driven, last-interglacial relative sea-level highstand preceded by a penultimate glacial-age lowstand. Instead, recent optically stimulated luminescence (OSL) dating suggests a last glacial age for these deposits, requiring >100 m of uplift since the last glacial maximum in order to keep pace with eustatic sea-level rise and implying the need for a wholesale revision of tectonic, stratigraphic and sea-level histories of the Gulf. These two hypotheses have radically different implications for regional neotectonics and land–sea distribution histories. Here we test these hypotheses using OSL dating of the zeugen formations. These new ages are remarkably consistent with earlier interpretations of the formations being last interglacial or older in age, showing that tectonic movements are negligible and eustatic sea-level variations are responsible for local sea-level changes in the Gulf. The cause of the large age differences between recent studies is unclear, although it appears related to large differences in the measured accumulated dose in different OSL samples.
Pediatric leukemias are among the most drug responsive of human malignancies. Over 80% of children with acute lymphoblastic leukemia (ALL) can now be cured by systemic chemotherapy. Because of their drug responsiveness, childhood leukemias remain an excellent model for evaluating the pharmacodynamics, kinetics, and genetics of anti-cancer drugs.
Pharmacokinetics is the study of the absorption, distribution, metabolism, and excretion of drugs. Pharmacodynamics characterizes the relationship between pharmacokinetics and pharmacologic effects, either adverse or therapeutic. Considerable interindividual variability exists in the pharmacokinetics and in the pharmacodynamics of many anti-leukemic agents in children. Pharmacogenetics/pharmacogenomics is the inherited basis for interindividual differences in pharmacokinetics/pharmacodynamics of medications, and the individualization of therapy based on germline genotypes may be one means of minimizing interindividual variability in response to anti-leukemic agents and optimizing treatment.
Many medications exhibit broad interpatient variability and for those drugs with a wide therapeutic index (e.g., penicillins), these patient-specific differences are unlikely to affect either efficacy or toxicity. For medications with wide therapeutic indices, the vast majority of patients can be given doses high enough to produce the desired therapeutic response with little risk of toxicity. In contrast, anti-leukemic agents have a very narrow therapeutic index with substantial risk for toxicity at doses required for therapeutic effects. Furthermore, the subset of patients with the highest rate of drug clearance (i.e., metabolism, elimination) may experience suboptimal systemic exposure (i.e., blood concentration) at standard doses. Those investigations of concentration–effect relationships that have been established and linked to host genetic polymorphisms are the primary focus of this chapter.
We consider a class of measure-valued Markov processes constructed by taking a superprocess over some underlying Markov process and conditioning it to stay alive forever. We obtain two representations of such a process. The first representation is in terms of an “immortal particle” that moves around according to the underlying Markov process and throws off pieces of mass, which then proceed to evolve in the same way that mass evolves for the unconditioned superprocess. As a consequence of this representation, we show that the tail σ-field of the conditioned superprocess is trivial if the tail σ-field of the underlying process is trivial. The second representation is analogous to one obtained by LeGall in the unconditioned case. It represents the conditioned superprocess in terms of a certain process taking values in the path space of the underlying process. This representation is useful for studying the “transience” and “recurrence” properties of the closed support process.
As applications for extreme ultraviolet (EUV) radiation have been identified, the demand for better optics has also increased. Thorium and thorium oxide thin films (19 to 61 nm thick) were RF-sputtered and characterized using atomic force microscopy (AFM), spectroscopic ellipsometry, low-angle x-ray diffraction (LAXRD), x-ray photoelectron spectroscopy (XPS), and x-ray absorption near edge structure (XANES) in order to assess their capability as EUV reflectors. Their reflectance and absorption at different energies were also measured and analyzed at the Advanced Light Source in Berkeley. The reflectance of oxidized thorium is reported between 2 and 32 nm at 5, 10, and 15 degrees from grazing. The imaginary component of the complex index of refraction, β, is also reported between 12.5 and 18 nm. Thin films of thorium were found to reflect better between 6.5 and 9.4 nm at 5 degrees from grazing than all other known materials, including iridium, gold, nickel, uranium dioxide, and uranium nitride. The measured reflectance does not coincide with reflectance curves calculated from the Center for X-Ray Optics (CXRO) atomic scattering factor data. We observe large energy shifts of up to 20 eV, suggesting the need for better film characterization and possibly an update of the tabulated optical constants.