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The National Enforcement Investigations Center of the EPA provides support services for the enforcement activities of the Agency. Recently, we have analyzed hazardous wastes as part of efforts to enforce the Resource Conservation and Recovery Act and the Superfund Act. Sample preparation for inorganic elemental analysis is a difficult and time-consuming step. Thus, it would be desirable to be able to use x-ray fluorescence methods which require relatively little sample preparation for the analysis of solid hazardous wastes. A major problem to be overcome is the need to calibrate for a large variety of samples. However, a compensating factor is that the error will be largely determined by the sampling error and the measurement accuracy is not quite so critical.
A range of precision farming technologies are used commercially for variable rate applications of nitrogen (N) for cereals, yet these usually adjust N rates from a pre-set value, rather than predicting economically optimal N requirements on an absolute basis. This paper reports chessboard experiments set up to examine variation in N requirements, and to develop and test systems for its prediction, and to assess its predictability. Results showed very substantial variability in fertiliser N requirements within fields, typically >150 kg ha−1, and large variation in optimal yields, typically >2 t ha−1. Despite this, calculated increases in yield and gross margin with N requirements perfectly matched across fields were surprisingly modest (compared to the uniform average rate). Implications are discussed, including the causes of the large remaining variation in grain yield, after N limitations were removed.
Optimising oilseed rape canopy size through correct management is crucial for maximising yield. Plant growth regulators (PGRs) and nitrogen (N) fertiliser are generally applied at a flat rate, however variable applications may be useful for the optimisation of canopy size. The aim of this paper was to understand the potential for spectral reflectance indices to predict green area index (GAI) and crop N content in winter oilseed rape, with specific focus on the Fritzmeier Isaria Crop Sensor. Three large oilseed rape chessboard experiments were set up in 2015 and 2016 in the UK. The results show good correlations between the Isaria indices and both GAI and crop N content, suggesting that the Isaria may be a useful tool for variably applying PGRs and N fertiliser to oilseed rape.
Cryptosporidium, a parasite known to cause large drinking and recreational water outbreaks, is tolerant of chlorine concentrations used for drinking water treatment. Human laboratory-based surveillance for enteric pathogens detected a cryptosporidiosis outbreak in Baker City, Oregon during July 2013 associated with municipal drinking water. Objectives of the investigation were to confirm the outbreak source and assess outbreak extent. The watershed was inspected and city water was tested for contamination. To determine the community attack rate, a standardized questionnaire was administered to randomly sampled households. Weighted attack rates and confidence intervals (CIs) were calculated. Water samples tested positive for Cryptosporidium species; a Cryptosporidium parvum subtype common in cattle was detected in human stool specimens. Cattle were observed grazing along watershed borders; cattle faeces were observed within watershed barriers. The city water treatment facility chlorinated, but did not filter, water. The community attack rate was 28·3% (95% CI 22·1–33·6), sickening an estimated 2780 persons. Watershed contamination by cattle probably caused this outbreak; water treatments effective against Cryptosporidium were not in place. This outbreak highlights vulnerability of drinking water systems to pathogen contamination and underscores the need for communities to invest in system improvements to maintain multiple barriers to drinking water contamination.
This paper describes the system architecture of a newly constructed radio telescope – the Boolardy engineering test array, which is a prototype of the Australian square kilometre array pathfinder telescope. Phased array feed technology is used to form multiple simultaneous beams per antenna, providing astronomers with unprecedented survey speed. The test array described here is a six-antenna interferometer, fitted with prototype signal processing hardware capable of forming at least nine dual-polarisation beams simultaneously, allowing several square degrees to be imaged in a single pointed observation. The main purpose of the test array is to develop beamforming and wide-field calibration methods for use with the full telescope, but it will also be capable of limited early science demonstrations.
Consumption of almonds has been shown to be associated with a decreased risk of CHD, which may be related to their fatty acid (FA) composition. However, the effect of almond consumption on the serum FA composition is not known. Therefore, in the present study, we investigated whether almond consumption would alter the serum FA profile and risk of CHD, as calculated using Framingham's 10-year risk score, in a dose-dependent manner in hyperlipidaemic individuals when compared with a higher-carbohydrate control group using dietary interventions incorporating almonds. A total of twenty-seven hyperlipidaemic individuals consumed three isoenergetic (mean 1770 kJ/d) supplements during three 1-month dietary phases: (1) full-dose almonds (50–100 g/d); (2) half-dose almonds with half-dose muffins; (3) full-dose muffins. Fasting blood samples were obtained at weeks 0 and 4 for the determination of FA concentrations. Almond intake (g/d) was found to be inversely associated with the estimated Framingham 10-year CHD risk score (P= 0·026). In both the half-dose and full-dose almond groups, the proportions of oleic acid (OA) and MUFA in the TAG fraction (half-almond: OA P= 0·003; MUFA P= 0·004; full-almond: OA P< 0·001; MUFA P< 0·001) and in the NEFA fraction (half-almond: OA P= 0·01; MUFA P= 0·04; full-almond: OA P= 0·12; MUFA P= 0·06) increased. The estimated Framingham 10-year CHD risk score was inversely associated with the percentage change of OA (P= 0·011) and MUFA (P= 0·016) content in the TAG fraction. The proportions of MUFA in the TAG and NEFA fractions were positively associated with changes in HDL-cholesterol concentrations. Similarly, the estimated Framingham 10-year CHD risk score was inversely associated with the percentage change of OA (P= 0·069) and MUFA content in the NEFA fraction (P= 0·009). In conclusion, the results of the present study indicate that almond consumption increases OA and MUFA content in serum TAG and NEFA fractions, which are inversely associated with CHD lipid risk factors and overall estimated 10-year CHD risk.
Contrary to concerns that fructose may have adverse metabolic effects, there is evidence that small, ‘catalytic’ doses ( ≤ 10 g/meal) of fructose decrease the glycaemic response to high-glycaemic index meals in human subjects. To assess the longer-term effects of ‘catalytic’ doses of fructose, we undertook a meta-analysis of controlled feeding trials. We searched MEDLINE, EMBASE, CINAHL and the Cochrane Library. Analyses included all controlled feeding trials ≥ 7 d featuring ‘catalytic’ fructose doses ( ≤ 36 g/d) in isoenergetic exchange for other carbohydrates. Data were pooled by the generic inverse variance method using random-effects models and expressed as mean differences (MD) with 95 % CI. Heterogeneity was assessed by the Q statistic and quantified by I2. The Heyland Methodological Quality Score assessed study quality. A total of six feeding trials (n 118) met the eligibility criteria. ‘Catalytic’ doses of fructose significantly reduced HbA1c (MD − 0·40, 95 % CI − 0·72, − 0·08) and fasting glucose (MD − 0·25, 95 % CI − 0·44, − 0·07). This benefit was seen in the absence of adverse effects on fasting insulin, body weight, TAG or uric acid. Subgroup and sensitivity analyses showed evidence of effect modification under certain conditions. The small number of trials and their relatively short duration limit the strength of the conclusions. In conclusion, this small meta-analysis shows that ‘catalytic’ fructose doses ( ≤ 36 g/d) may improve glycaemic control without adverse effects on body weight, TAG, insulin and uric acid. There is a need for larger, longer ( ≥ 6 months) trials using ‘catalytic’ fructose to confirm these results.
High fluence ion implantation of N (1x1018/cm2 at 150 keV) has been used to form buried nitride layers in (110) silicon. After annealing at 1200 C for 5 hrs. a continuous, polycrystalline alpha-Si,N- layer (200 nm thick) is observed beneath a surface silicon film 306 nm thick. The upper Si/Si3N4 interface appears to be more abrupt than that observed in (100) silicon with minimal dendritic intergrowth and no evidence for microtwinning in the silicon. Furthermore, a band of nitride precipitates can be detected 500 nm below the continuous nitride layer. These nitride precipitates grow semi-coherently within the silicon with no observable strain or misfit dislocations within the silicon. The nitride precipitates are internally faulted to accomodate the 10% lattice mismatch in the (0001) nitride direction. Short term anneals reveal that the precipitates have fully crystallized within 10 min. at 1200 C while the continuous nitride layer is still amorphous.
During the past few years we have been studying several of the physical processes relevant to the production of spherical shells for inertial confinement fusion targets, both in a microgravity environment and in a containerless environment. The work has led to the development of several experimental facilities. Those which are most unique are described here, and fall into three categories as follows: 1. Ones which provide an induced low- or microgravity containerless environment, such as a vertical drag-free wind tunnel, two differing low-pressure and/or high-temperature drop towers for processing metallic or metallic-glass specimens, and a neutral buoyancy tank, 2. Ones providing containerless processing capability, such as a focusing radiator and an electrostatic levitator and 3. Ones providing extended microgravity and containerless capabilities, such as the KC-135 aircraft and the Space Processing Application Rockets. The physical processes which we have been studying include, but are not limited to, those which establish the shell sphericity, concentricity, surface topology, material properties, coatings, heating and cooling requirements and the effects of gravity on fusion pellet fabrication processes.
Bioimpedance spectroscopy (BIS) has been used to track changes in total body water (TBW). Accurate TBW estimations can be influenced by both methodological and biological factors. One methodological variation that contributes to BIS TBW errors is the electrode placement. The purpose of the present study was to compare the reproducibility and validity of fixed-distance electrode placements (5 cm) with the standard single-site electrode placements. Twenty-nine subjects (fifteen men and fourteen women) participated in the reproducibility study, while sixty-nine subjects (thirty-three men and thirty-six women) participated in the validity study. The reproducibility study included two measurements that were taken 24 h apart, while the validity study consisted of a 12-week exercise intervention with measurements taken at weeks 1 and 12. TBW was estimated using BIS and 2H techniques. Reproducibility results indicated that fixed-distance electrodes reduced the day-to-day standard error of the measurement in men (from 1·13 to 0·81 litres) but not in women (0·47 litres). sem values were lower for women than for men, suggesting that BIS TBW estimates are sex dependent. Validity results produced similar accurate findings (mean difference < 0·21 litres). However, fixed-distance electrodes improved delta TBW errors (mean difference improvements>0·04 litres in men, women, and men and women combined). When tracking changes in TBW, fixed-distance electrodes may reduce reproducibility errors and allow for smaller changes to be detected. However, the reduction of reproducibility errors may be greater for men than for women. Therefore, reproducibility calculations should be based on the sex of the sample population.
Background: Subjective Units of Distress Scale (SUDS) ratings are commonly used during exposure tasks in cognitive behavioral treatment (CBT) for anxiety. Aims: The present study examined patterns and predictors of SUDS in a sample of anxiety-disordered youth. Method: Youth (N = 99) aged 7 to 14 (M = 10.4, SD = 1.8) were treated with CBT for social phobia (SP), generalized anxiety disorder (GAD), and/or separation anxiety disorder (SAD). Analyses were conducted using hierarchical linear modeling. Results: Child's peak SUDS and magnitude of change in SUDS significantly increased between sessions. Higher child self-reported pretreatment total Multidimensional Anxiety Scale for Children (MASC) score predicted greater change in SUDS within the first exposure session. Primary GAD diagnosis predicted less increase in change in SUDS between sessions. Conclusions: Results suggest that higher pretreatment total MASC scores are associated with increased first exposure within-session habituation. Additionally, youth with a principal diagnosis of GAD experienced less between-session habituation, perhaps because they may have required more imaginal than in-vivo exposures.
The potency in man of eight different commercial vaccines and an experimental vaccine, as judged by the antibody response after the primary course of two injections and after a booster dose 9–12 months later, was compared. All the vaccines produced good responses to Types 2 and 3 but some were less satisfactory for Type 1. The relation of potency to protection in man is discussed and the use of one of the vaccines as a minimum standard for this country is suggested.
Social phobia (SP) is characterized by a fear of one or more social or performance situations. Studies of comorbidity in SP youth find anxiety and affective disorders co-occurring. The present study examined children with primary SP and compared them to children with primary Separation Anxiety Disorder (SAD) or Generalized Anxiety Disorder (GAD) prior to treatment and in response to treatment. The groups differed significantly on self-, parent- and teacher-rated pretreatment measures. Additionally, the two groups showed differential treatment outcomes. When the SP youth with comorbid Affective Disorder were excluded in treatment outcome analyses, there were non significant differences, indicating that comorbid affective disorders likely contributed to differential treatment outcome. Results are discussed in terms of treatment recommendations for socially phobic youth.
Twenty-three chronic nonfluent aphasia patients with moderate or
severe word-finding impairments and 11 with profound word-finding
impairments received two novel picture-naming treatments. The intention
treatment initiated picture-naming trials with a complex left-hand
movement and was designed to enhance right frontal participation during
word retrieval. The attention treatment required patients to view visual
stimuli for picture-naming trials in their left hemispace and was designed
to enhance right posterior perisylvian participation during word
retrieval. Because the intention treatment addressed action mechanisms and
nonfluent aphasia reflects difficulty initiating or maintaining action
(i.e., language output), it was hypothesized that intention component of
the treatment would enhance re-acquisition of picture naming more than the
attention component. Patients with moderate and severe word-finding
impairment showed gains with both treatments but greater incremental
improvement from one treatment phase to the next with the intention than
the attention treatment. Thus, the hypothesis that intention component
would be a more active constituent than the attention component was
confirmed for these patients. Patients with profound word-finding
impairment showed some improvement with both treatments but no
differential effects for the intention treatment. Almost all patients who
showed treatment gains on either treatment also demonstrated
generalization from trained to untrained items. (JINS, 2007,
Implantation of nitrogen at 150 KeV and a dose of 1 ⊠ 1018/cm2 into (110) silicon results in the formation of an amorphized layer at the mean ion range, and a deeper tail of nitrogen ions. Annealing studies show that the amorphized layer recrystallizes into a continuous polycrystalline Si3N4 layer after annealing for 1 h at 1200 °C. In contrast, the deeper nitrogen fraction forms discrete precipitates (located 1μm below the wafer surface) in less than 1 min at this temperature. The arcal density of these precipitates is 5 ⊠ 107/cm2 compared with a nuclei density of 1.6 ⊠ 105/cm2 in the amorphized layer at comparable annealing times. These data suggest that the nucleation step limits the recrystallization rate of amorphous silicon nitride to form continuous buried nitride layers. The nitrogen located within the damaged crystalline silicon lattice precipitates very rapidly, yielding semicoherent crystallites of β–Si3N4.
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