Noise and signal transmission properties as agents of selection in the vibrational communication environment

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on February 25, 2008)Vita.Thesis (Ph. D.) University of Missouri-Columbia 2007.Members of the Enchenopa binotata species complex (Hemiptera: Membracidae) are host-specific phytophagous insects that communicate by sending vibrations through their host plants. Successful communication depends on the prevailing ecological and environmental conditions, which can affect communication behavior and the evolution of signals and sensory structures. Here I address how male and female E. binotata behaviorally respond to noise, and whether variation in plant transmission properties can promote divergent selection on vibrational mating signals. When presented with vibrational noise derived from wind males and females reduce their signaling behavior. However, individuals use strategies such as gap detection, which allow communication to persist during low levels of noise. The evolution of signals is strongly affected by how signals transmit through plant stems and leaves. Using a novel method to measure plant stem vibrations I also illustrate differences in plant transmission properties between the host plants of two closely related E. binotata species. Each E. binotata species appears to have responded to these transmission differences: both insect species use a signal frequency that transmits well in their contrasting communication environments, which suggests further that shifting to new host plants may favor signal divergence and ultimately, behavioral isolation.Includes bibliographical reference

Optimal molecular alignment and orientation through rotational ladder climbing

We study the control by electromagnetic fields of molecular alignment and orientation, in a linear, rigid rotor model. With the help of a monotonically convergent algorithm, we find that the optimal field is in the microwave part of the spectrum and acts by resonantly exciting the rotation of the molecule progressively from the ground state, i.e., by rotational ladder climbing. This mechanism is present not only when maximizing orientation or alignment, but also when using prescribed target states that simultaneously optimize the efficiency of orientation/alignment and its duration. The extension of the optimization method to consider a finite rotational temperature is also presented.Comment: 14 pages, 12 figure

Stationary and non-stationary deconvolution to recover long-term transfer functions

To design a ground heat exchanger, simulations are frequently used. One way to perform simulations is to use the well-known g-functions to obtain the ground temperature. These functions are usually obtained by analytical or numerical models, which limits the precision or takes long simulation time. Recent advances show that the short-term g-functions can also be retrieved by a deconvolution algorithm. However, the known deconvolution algorithm is only validated for a set of operating parameters and duration of less than 10 days. A first objective of this article is to demonstrate that longer g-functions can be retrieved with such an algorithm. Then, a second objective is to extend the application of the deconvolution to consider time varying operating parameters throughout a ground heat exchanger's operation. To achieve those objectives, the deconvolution will be first applied to various numerical year-long simulations of a ground source heat pump system with stationary conditions. Then, an extended multi-signal deconvolution will be applied to a non-stationary thermal response test of 30 days. Both tests show adequate temperature reconstruction with RMSE of less than 0.05 °C and 0.2 °C for the first and second scenarios respectively

EFFECT OF BOOST PRESSURE AND INJECTION STRATEGY TO THE IN-CYLINDER PRESSURE AND HEAT RELEASE RATE OF DIRECT INJECTION DIESEL ENGINE

An optimum diesel engine helps to solve the increasing energy demand, the depletion of fossil fuels, and the environmental problems from the utilization of combustion engines. To optimise the operation of a direct injection diesel engine, the effects of various boost pressures under different rotations and main injection timings were studied experimentally and numerically. The boost pressure was set between 0 kPa to 60 kPa with increment of 20 kPa using a supercharger. The engine rotation was set between 800 RPM to 2000 RPM with an increment of 400 RPM. The main injection timing was varied with 2° increment from 1° BTDC to 3° ATDC. The results indicated the increase of in-cylinder pressure and heat release rate with increased boost pressure. Higher engine rotation led to the decrease of the maximum heat release rate, maximum in-cylinder pressure, and the difference between the magnitude of the first and second onsets of the in-cylinder pressure raise. It also shifted the timing for the peak of the heat release rate to occur further away from TDC. The change of the main injection timing from 1° BTDC to 3° ATDC decreased the maximum in-cylinder pressure and moved the location of the maximum in-cylinder pressure away from TDC. The delay of the main injection timing brought larger in-cylinder pressure raise for the first onset but lower cumulative heat release rate. The difference between experimental and numerical measurements of the in-cylinder pressure was found to be less than 4%. The results of the study suggested that boost pressure of 60 kPa and main injection timing of the 1° BTDC provide higher in-cylinder pressure and cumulative heat release rate and consequently better engine performance

Comorbid anxiety increases cognitive control activation in Major Depressive Disorder

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134086/1/da22541.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134086/2/da22541_am.pd

Arctic soil methane sink increases with drier conditions and higher ecosystem respiration

Arctic wetlands are known methane (CH4) emitters but recent studies suggest that the Arctic CH4 sink strength may be underestimated. Here we explore the capacity of well-drained Arctic soils to consume atmospheric CH4 using >40,000 hourly flux observations and spatially distributed flux measurements from 4 sites and 14 surface types. While consumption of atmospheric CH4 occurred at all sites at rates of 0.092 ± 0.011 mgCH4 m−2 h−1 (mean ± s.e.), CH4 uptake displayed distinct diel and seasonal patterns reflecting ecosystem respiration. Combining in situ flux data with laboratory investigations and a machine learning approach, we find biotic drivers to be highly important. Soil moisture outweighed temperature as an abiotic control and higher CH4 uptake was linked to increased availability of labile carbon. Our findings imply that soil drying and enhanced nutrient supply will promote CH4 uptake by Arctic soils, providing a negative feedback to global climate change

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Genome-wide association study of Tourette Syndrome

Tourette Syndrome (TS) is a developmental disorder that has one of the highest familial recurrence rates among neuropsychiatric diseases with complex inheritance. However, the identification of definitive TS susceptibility genes remains elusive. Here, we report the first genome-wide association study (GWAS) of TS in 1285 cases and 4964 ancestry-matched controls of European ancestry, including two European-derived population isolates, Ashkenazi Jews from North America and Israel, and French Canadians from Quebec, Canada. In a primary meta-analysis of GWAS data from these European ancestry samples, no markers achieved a genome-wide threshold of significance (p<5 × 10−8); the top signal was found in rs7868992 on chromosome 9q32 within COL27A1 (p=1.85 × 10−6). A secondary analysis including an additional 211 cases and 285 controls from two closely-related Latin-American population isolates from the Central Valley of Costa Rica and Antioquia, Colombia also identified rs7868992 as the top signal (p=3.6 × 10−7 for the combined sample of 1496 cases and 5249 controls following imputation with 1000 Genomes data). This study lays the groundwork for the eventual identification of common TS susceptibility variants in larger cohorts and helps to provide a more complete understanding of the full genetic architecture of this disorder

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication