468 research outputs found
Research Notes : The effects of temperature on longevity and vitality of soybean seeds
Studies involving longevity and vitality of seeds after subjection to certain environmental conditions are both numerous and include many species of seeds. When stored under laboratory room conditions, year-to-year plant-Lngs are required to maintain adequate quantities of viable soybean seeds for the basic genetics laboratories. Begun in 1971, this study was under-taken for the purpose of investigating the role of temperature in maintaining high germination percentages in seeds subjected to an extended period of storage
Heroism and Wellbeing in the 21st Century: Applied and Emerging Perspectives
Offering a holistic take on an emerging field, this edited collection examines how heroism manifests, is appropriated, and is constructed in a broad range of settings and from a variety of disciplines and perspectives. Psychologists, educators, lawyers, researchers and cultural analysts consider how heroism intersects with wellbeing, and how we still use—and even abuse—heroism as a vehicle to thrive and prosper in the everyday and in the face of the most unbearable situations. Highlighting some of the most pressing issues in today’s world—including genocide, racism, deceitful business practices, bystanderism, mental health, unethical governance and the global refugee crisis—this book applies a critical psychological perspective in synthesizing the social construction of heroism and wellbeing, contributing to the development of global wellbeing indicators and measures.https://scholarship.richmond.edu/bookshelf/1321/thumbnail.jp
The impact of low-density and sub-patent Plasmodium falciparum infections on transmission and disease
Low parasite density Plasmodium falciparum infections are often not detectable by conventional diagnostics. The natural history and clinical consequences of untreated low-density infection has not been fully described. These infections also may be contributing to the infectious reservoir of parasites in humans, which sustains transmission. However, the relationship between parasite density and onward transmission is poorly understood. Using a 54-month longitudinal cohort of 757 people from 75 households across five villages in Western Kenya, this dissertation aimed to (1) estimate the effect of having a sub-patent infection on subsequent clinical episodes and (2) determine the relationship between parasite density in humans and successful human-to-mosquito transmission.With inverse probability weighted Kaplan Meier curves, aim 1 found that over 54 months, 1,128 symptomatic episodes of suspected malaria were RDT-negative, of which 400 (35.5%) harbored sub-patent P. falciparum infections. Overall, the risk of developing clinical malaria within 60 days was low (7.7% (95% Confidence Interval (CI): 6.0%, 9.4%)). Transmission season modified the relationship between sub-patent infections and risk of clinical malaria (RD low season: 2.3%, CI: 0.4%, 4.2%; RD high season: -4.8%, CI: -9.53%, -0.05%). Next, adapting a previously published probabilistic model to estimate transmission, Aim 2 identified that compared to high-parasite density infections, low-parasite density infections had almost 80% higher odds of human to mosquito transmission (OR: 1.92, CI: 1.54, 2.42). Infections during the high transmission season were also more likely to transmit to mosquitos. These findings indicate that sub-patent infections have a slightly elevated risk in the low-transmission season, which may merit alternate management but RDT’s diagnose the majority of clinically relevant infections in the high transmission season. Low-density infections, which are often sub-patent, are also an important source for mosquito infections. Taken together, this work highlights the public health importance of low-density infections and provides rationale to specifically target low-density infections in order to progress malaria elimination efforts.Doctor of Philosoph
On the Oligomeric State of DJ-1 Protein and Its Mutants Associated with Parkinson Disease A COMBINED COMPUTATIONAL AND IN VITRO STUDY
Mutations in the DJ-1 protein are present in patients suffering from familial Parkinson disease. Here we use computational methods and biological assays to investigate the relationship between DJ-1 missense mutations and the protein oligomeric state. Molecular dynamics calculations suggest that: (i) the structure of DJ-1 wild type (WT) in aqueous solution, in both oxidized and reduced forms, is similar to the crystal structure of the reduced form; (ii) the Parkinson disease-causing M26I variant is structurally similar to the WT, consistent with the experimental evidence showing the protein is a dimer as WT; (iii) R98Q is structurally similar to the WT, consistent with the fact that this is a physiological variant; and (iv) the L166P monomer rapidly evolves toward a conformation significantly different from WT, suggesting a change in its ability to oligomerize. Our combined computational and experimental approach is next used to identify a mutant (R28A) that, in contrast to L166P, destabilizes the dimer subunit-subunit interface without significantly changing secondary structure elements
Glycaemic patterns in healthy elderly individuals and in those with impaired glucose metabolism - exploring the relationship with nonglycaemic variables.
OBJECTIVE
The SENIORLABOR study data were explored (i) to examine the evolution during senescence of the differences between measured glycated haemoglobin (HbA1c) values and the values predicted by using regression to extrapolate from measured fructosamine levels; (ii) to scrutinise the relationship between the glycation gap and insulin resistance using a homeostasis model assessment, and between the glycation gap and a low-grade inflammation marker (C-reactive protein serum concentration); and (iii) to investigate the glycation gap ranges in relation to triglyceride levels and kidney function.
SUBJECTS AND METHODS
A total of 1432 Swiss individuals aged >60 years and classified as healthy (547), prediabetic (701) or diabetic (184) based on their fasting plasma glucose and HbA1c values were included in the study. The glycation gap was evaluated and assigned to one of four categories: <−0.5; −0.5 to <0.0; 0.0 to ≤0.5; >0.5.
RESULTS
In healthy and prediabetic participants, the homeostasis model assessment for estimation of insulin resistance (p <0.01), high-sensitivity C-reactive protein (p <0.001) and triglyceride (p = 0.02) values tended to increase with increasing glycation gap category and were highest in the glycation gap category >0.5. Homeostasis model assessment for estimation of insulin resistance, high-sensitivity C-reactive protein and triglyceride levels tended to increase with increasing glycation gap category and were highest in the glycation gap category >0.5. Significant differences (p <0.01) between glycation gap categories were seen among different high-sensitivity C-reactive protein concentration groups. Interestingly, in diabetic participants, homeostasis model assessment for estimation of insulin resistance values, triglyceride concentrations and estimation of glomerular filtration values all decreased with decreasing glycation gap category. In the group of participants with a glycation gap >0.5, high-sensitivity C-reactive protein values tended to increase with increasing glycation gap, whereas for participants with type 2 diabetes and in the glycation gap group >0.5, high-sensitivity C-reactive protein levels tended to decrease as the glycation gap increased. The percentage of participants with type 2 diabetes mellitus increased from 2% in the glycation gap category <−0.5 to 76% in the glycation gap category >0.5. In contrast, the percentage of healthy participants fell from 85% to 7%.
CONCLUSION
This is the first time that a direct comparison of healthy, prediabetic and diabetic participants, all assessed under identical conditions and using identical methodology, has clearly demonstrated a different glycation gap pattern. Thus, we contribute evidence that the glycation gap might be of interest in the care of diabetic patients and their prophylaxis, while acknowledging that more studies are needed to confirm our findings. (Trial registration number ISRCTN53778569)
Sleep Macrostructure and NREM Sleep Instability Analysis in Pediatric Developmental Coordination Disorder
Developmental Coordination Disorder (DCD) is considered to be abnormal motor skills learning, identified by clumsiness, slowness, and/or motor inaccuracy impairing the daily-life activities in all ages of life, in the absence of sensory, cognitive, or neurological deficits impairment. The present research focuses on studying DCD sleep structure and Cyclic Alternating Pattern (CAP) parameters with a full overnight polysomnography and to study the putative correlations between sleep architecture and CAP parameters with motor coordination skills. The study was a cross-sectional design involving 42 children (26M/16F; mean age 10.12 ± 1.98) selected as a DCD group compared with 79 children (49M/30F; mean age 9.94 ± 2.84) identified as typical (no-DCD) for motor ability and sleep macrostructural parameters according to the MABC-2 and polysomnographic (PSG) evaluations. The two groups (DCD and non-DCD) were similar for age (p = 0.715) and gender (p = 0.854). More significant differences in sleep architecture and CAP parameters were found between two groups and significant correlations were identified between sleep parameters and motor coordination skills in the study population. In conclusion, our data show relevant abnormalities in sleep structure of DCD children and suggest a role for rapid components of A phases on motor coordination development
Bringing Agriculture into the GATT: Negotiating a Framework for Action
International Relations/Trade,
A placebo-controlled, double-blind, dose-escalation study to assess the safety, tolerability and pharmacokinetics/pharmacodynamics of single and multiple intravenous infusions of AZD9773 in patients with severe sepsis and septic shock
INTRODUCTION: Tumor necrosis factor-alpha (TNF-α), an early mediator in the systemic inflammatory response to infection, is a potential therapeutic target in sepsis. The primary objective of this study was to determine the safety and tolerability of AZD9773, an ovine, polyclonal, anti-human TNF-α Fab preparation, in patients with severe sepsis. Secondary outcomes related to pharmacokinetic (PK) and pharmacodynamic (PD) parameters.
METHODS: In this double-blind, placebo-controlled, multicenter Phase IIa study, patients were sequentially enrolled into five escalating-dose cohorts (single doses of 50 or 250 units/kg; multiple doses of 250 units/kg loading and 50 units/kg maintenance, 500 units/kg loading and 100 units/kg maintenance, or 750 units/kg loading and 250 units/kg maintenance). In each cohort, patients were randomized 2:1 to receive AZD9773 or placebo.
RESULTS: Seventy patients received AZD9773 (n=47) or placebo (n=23). Baseline characteristics were similar across cohorts. Mean baseline APACHE score was 25.9. PK data demonstrated an approximately proportional increase in concentration with increasing dose and a terminal half-life of 20 hours. For the multiple-dose cohorts, serum TNF-α concentrations decreased to near-undetectable levels within two hours of commencing AZD9773 infusion. This suppression was maintained in most patients for the duration of treatment. AZD9773 was well tolerated. Most adverse events were of mild-to-moderate intensity and considered by the reporting investigator as unrelated to study treatment.
CONCLUSIONS: The safety, PK and PD data support the continued evaluation of AZD9773 in larger Phase IIb/III studies
Aberration-free ultra-thin flat lenses and axicons at telecom wavelengths based on plasmonic metasurfaces
The concept of optical phase discontinuities is applied to the design and
demonstration of aberration-free planar lenses and axicons, comprising a phased
array of ultrathin subwavelength spaced optical antennas. The lenses and
axicons consist of radial distributions of V-shaped nanoantennas that generate
respectively spherical wavefronts and non-diffracting Bessel beams at telecom
wavelengths. Simulations are also presented to show that our aberration-free
designs are applicable to high numerical aperture lenses such as flat
microscope objectives
Quantum Zeno Effect and Light-Dark Periods for a Single Atom
The quantum Zeno effect (QZE) predicts a slow-down of the time development of
a system under rapidly repeated ideal measurements, and experimentally this was
tested for an ensemble of atoms using short laser pulses for non-selective
state measurements. Here we consider such pulses for selective measurements on
a single system. Each probe pulse will cause a burst of fluorescence or no
fluorescence. If the probe pulses were strictly ideal measurements, the QZE
would predict periods of fluorescence bursts alternating with periods of no
fluorescence (light and dark periods) which would become longer and longer with
increasing frequency of the measurements. The non-ideal character of the
measurements is taken into account by incorporating the laser pulses in the
interaction, and this is used to determine the corrections to the ideal case.
In the limit, when the time between the laser pulses goes to zero, no freezing
occurs but instead we show convergence to the familiar macroscopic light and
dark periods of the continuously driven Dehmelt system. An experiment of this
type should be feasible for a single atom or ion in a trapComment: 16 pages, LaTeX, a4.sty; to appear in J. Phys.
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