2,142 research outputs found
Western Bean Cutworm in Iowa, Illinois, Indiana and Now Ohio: Did Biotech Corn Influence the Spread of this Pest?
The western bean cutworm, Striacosta albicosta (Lepidoptera: Noctuidae), is native to North America. It was first reported as a pest of Colorado pinto beans in 1915. In 1935, adults were captured in western Nebraska (Hagen 1963) and later, in 1954, it was identified as a pest of corn in southern Idaho (Blickenstaff 1979). Since its discovery in the late 1880s, it has slowly and steadily expanded its known distribution eastward from Arizona to Iowa (Rice 2000) and Minnesota (O\u27Rourke and Hutchison 2000). The western bean cutworm was known to occasionally occur in western Iowa prior to 1975, but it was not until2000 that an economically damaging population was found in field corn. Since then, it has become an annual economic pest in western and central regions of the state. In 2004, western bean cutworms were collected in pheromone traps for the first time in Illinois and Missouri
Crystallization of random trigonometric polynomials
We give a precise measure of the rate at which repeated differentiation of a
random trigonometric polynomial causes the roots of the function to approach
equal spacing. This can be viewed as a toy model of crystallization in one
dimension. In particular we determine the asymptotics of the distribution of
the roots around the crystalline configuration and find that the distribution
is not Gaussian.Comment: 10 pages, 3 figure
Recommended from our members
Can Circle Hook Use Benefit Billfishes?
We performed a quantitative review to evaluate circle hook use in recreational and commercial hook-and-line fisheries that interact with billfishes (Family: Istiophoridae). Specifically, we scrutinized the findings of 11 recent empirical studies that reported, on a species-specific basis, side-by-side measures of circle vs. J-hook fishing performance: catch, mortality, deep-hooking and bleeding rates. Of the 30 total comparisons extracted from the literature that satisfied our inclusion criteria, 13 indicated significant differences between hook types for the specific metric compared. No study reported significant billfish catch rate differences between hook types. However, when significant differences between hook types were found, higher mortality rates and higher rates of deep-hooking and bleeding were associated with J-hooks relative to circle hooks. We conclude that empirical evidence is sufficient to promote circle hook use in almost all hook-and-line fishery sectors that typically interact with istiophorids. However, billfish conservation benefits will only be realized if fishers use unmodified circle hooks, commit to releasing live fish and take other appropriate measures which maximize post-release survival. While there may be fishing modes where circle hook effects are negative, for billfish conservation, we recommend managers grant exceptions to circle hook use only when experimental results support such a practice
Cloning, purification and preliminary crystallographic analysis of a putative pyridoxal kinase from Bacillus subtilis
A putative pyridoxal kinase from B. subtilis has been cloned, overexpressed, purified and crystallized and data have been collected to 2.8β
Γ
resolution
Association of Urinary Bisphenol A Concentration with Heart Disease: Evidence from NHANES 2003/06
BACKGROUND: Bisphenol A (BPA) is a high production volume chemical widely used in food and drinks packaging. Associations have previously been reported between urinary BPA concentrations and heart disease, diabetes and liver enzymes in adult participants of the National Health and Nutrition Examination Survey (NHANES) 2003/04. We aimed to estimate associations between urinary BPA concentrations and health measures in NHANES 2005/06 and in data pooled across collection years. METHODOLOGY AND FINDINGS: A cross-sectional analysis of NHANES: subjects were n = 1455 (2003/04) and n = 1493 (2005/06) adults aged 18-74 years, representative of the general adult population of the United States. Regression models were adjusted for age, sex, race/ethnicity, education, income, smoking, BMI, waist circumference, and urinary creatinine concentration. Main outcomes were reported diagnoses of heart attack, coronary heart disease, angina and diabetes and serum liver enzyme levels. Urinary BPA concentrations in 2005/06 (geometric mean 1.79 ng/ml, 95% CI: 1.64 to 1.96) were lower than in 2003/04 (2.49 ng/ml, CI: 2.20 to 2.83, difference p-value = 0.00002). Higher BPA concentrations were associated with coronary heart disease in 2005/06 (OR per z-score increase in BPA = 1.33, 95%CI: 1.01 to 1.75, p = 0.043) and in pooled data (OR = 1.42, CI: 1.17 to 1.72, p = 0.001). Associations with diabetes did not reach significance in 2005/06, but pooled estimates remained significant (OR = 1.24, CI: 1.10 to 1.40, p = 0.001). There was no overall association with gamma glutamyl transferase concentrations, but pooled associations with alkaline phosphatase and lactate dehydrogenase remained significant. CONCLUSIONS: Higher BPA exposure, reflected in higher urinary concentrations of BPA, is consistently associated with reported heart disease in the general adult population of the USA. Studies to clarify the mechanisms of these associations are urgently needed
The Wide Brown Dwarf Binary Oph 1622-2405 and Discovery of A Wide, Low Mass Binary in Ophiuchus (Oph 1623-2402): A New Class of Young Evaporating Wide Binaries?
We imaged five objects near the star forming clouds of Ophiuchus with the
Keck Laser Guide Star AO system. We resolved Allers et al. (2006)'s #11 (Oph
16222-2405) and #16 (Oph 16233-2402) into binary systems. The #11 object is
resolved into a 243 AU binary, the widest known for a very low mass (VLM)
binary. The binary nature of #11 was discovered first by Allers (2005) and
independently here during which we obtained the first spatially resolved R~2000
near-infrared (J & K) spectra, mid-IR photometry, and orbital motion estimates.
We estimate for 11A and 11B gravities (log(g)>3.75), ages (5+/-2 Myr),
luminosities (log(L/Lsun)=-2.77+/-0.10 and -2.96+/-0.10), and temperatures
(Teff=2375+/-175 and 2175+/-175 K). We find self-consistent DUSTY evolutionary
model (Chabrier et al. 2000) masses of 17+4-5 MJup and 14+6-5 MJup, for 11A and
11B respectively. Our masses are higher than those previously reported (13-15
MJup and 7-8 MJup) by Jayawardhana & Ivanov (2006b). Hence, we find the system
is unlikely a ``planetary mass binary'', (in agreement with Luhman et al. 2007)
but it has the second lowest mass and lowest binding energy of any known
binary. Oph #11 and Oph #16 belong to a newly recognized population of wide
(>100 AU), young (<10 Myr), roughly equal mass, VLM stellar and brown dwarf
binaries. We deduce that ~6+/-3% of young (<10 Myr) VLM objects are in such
wide systems. However, only 0.3+/-0.1% of old field VLM objects are found in
such wide systems. Thus, young, wide, VLM binary populations may be
evaporating, due to stellar encounters in their natal clusters, leading to a
field population depleted in wide VLM systems.Comment: Accepted version V2. Now 13 pages longer (45 total) due to a new
discussion of the stability of the wide brown dwarf binary population, new
summary Figure 17 now included, Astrophysical Journal 2007 in pres
Habitat-Distribution Modeling of a Recolonizing Black Bear, Ursus americanus, Population in the Trans-Pecos Region of Texas
Black Bears (Ursus americanus) were once widespread across Texas, but their numbers were reduced in the early 1900s. Recolonization of the Trans-Pecos region of Texas has occurred via bears migrating northward from Mexico. Recent bear sightings have increased in this area. This could be an indication that the population in Texas is beginning to recover, but the population will continue to expand only if there is suitable habitat to occupy. To help identify suitable habitat and restoration areas, we developed a predictive habitat-distribution model by using records of Black Bear sightings from 1996 to 2003 to map the species' distribution. Using Bayesian statistics, we modeled the probability of occurrence of Black Bears in the Trans-Pecos region based on sighting locations. We used GIS layers for land use/landcover, elevation, water sources, and road networks to obtain covariates in our modeling. We used a 10-fold cross-validation to test the effectiveness of using sighting data. Our results indicated a negative association with bare areas, agriculture, and grassland landcovers. In addition, southern aspect, elevation, distance to water, slope, and western aspect also influenced suitable habitat. Both the original and validation datasets correctly classified bear sightings 93.9% and 93.7% of the time, respectively. Our model can be used to target restoration efforts to enhance the ability of the Black Bear to expand in the Trans-Pecos region. It can also identify private landowners most likely to be affected by the expansion of Black Bears for education and cooperative efforts
Update to the Vitamin C, Thiamine and Steroids in Sepsis (VICTAS) protocol: statistical analysis plan for a prospective, multicenter, double-blind, adaptive sample size, randomized, placebo-controlled, clinical trial.
BACKGROUND: Observational research suggests that combined therapy with Vitamin C, thiamine and hydrocortisone may reduce mortality in patients with septic shock.
METHODS AND DESIGN: The Vitamin C, Thiamine and Steroids in Sepsis (VICTAS) trial is a multicenter, double-blind, adaptive sample size, randomized, placebo-controlled trial designed to test the efficacy of combination therapy with vitamin C (1.5βg), thiamine (100βmg), and hydrocortisone (50βmg) given every 6βh for up to 16 doses in patients with respiratory or circulatory dysfunction (or both) resulting from sepsis. The primary outcome is ventilator- and vasopressor-free days with mortality as the key secondary outcome. Recruitment began in August 2018 and is ongoing; 501 participants have been enrolled to date, with a planned maximum sample size of 2000. The Data and Safety Monitoring Board reviewed interim results at N =β200, 300, 400 and 500, and has recommended continuing recruitment. The next interim analysis will occur when N =β1000. This update presents the statistical analysis plan. Specifically, we provide definitions for key treatment and outcome variables, and for intent-to-treat, per-protocol, and safety analysis datasets. We describe the planned descriptive analyses, the main analysis of the primary end point, our approach to secondary and exploratory analyses, and handling of missing data. Our goal is to provide enough detail that our approach could be replicated by an independent study group, thereby enhancing the transparency of the study.
TRIAL REGISTRATION: ClinicalTrials.gov, NCT03509350. Registered on 26 April 2018
Chlorine Inactivation of Highly Pathogenic Avian Influenza Virus (H5N1)
To determine resistance of highly pathogenic avian influenza (H5N1) virus to chlorination, we exposed allantoic fluid containing 2 virus strains to chlorinated buffer at pH 7 and 8, at 5Β°C. Free chlorine concentrations typically used in drinking water treatment are sufficient to inactivate the virus by >3 orders of magnitude
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