545 research outputs found

    Pesticide Drift: A Problem in Iowa?

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    Pesticide drift ranks as the most frequent incident reported to the Iowa Department of Agriculture and Land Stewardship (IDALS). Pesticide drift, as defined by the U.S. Environmental Protection Agency (EPA) 40 CFR 162.3, means any movement of a pesticide during or immediately after application or use through air to a site other than the intended site of application or use

    Wavelet analysis of stratosphere gravity wave packets over Macquarie Island 1. Wave parameters

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    We describe a technique to detect gravity wave packets in high-resolution radiosonde soundings of horizontal wind and temperature. The vertical profiles of meridional and zonal wind speeds are transformed using the Morlet wavelet, and regions of high wind variance in height-wavenumber space are identified as gravity wave packets. Application of the Stokes parameter analysis to horizontal wind and temperature profiles of the reconstructed wave packets yields the wave parameters. The technique was applied to twice-daily radiosonde launches at Macquarie Island (55°S, 159°E) between 1993 and 1995. A strong seasonal cycle in the total wave variance was found, with a maximum in winter. The amount of wave energy propagating downward from the upper stratosphere also maximized in winter. Waves propagated predominately toward the southwest in winter, but in summer propagation directions were approximately isotropic. The intrinsic frequencies were close to the inertial frequency, and the waves had inferred horizontal wavelengths of several hundred kilometers.Florian Zink and Robert A. Vincen

    Does entry to center-based childcare affect gut microbial colonization in young infants?

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    Entry to center-based childcare (CC) at three months of life can be an important challenge for infants as it includes major stressors such as long maternal separations and frequently changing caregivers. Stress and the new environment may in turn alter the composition of the gut microbiota with possible implications for future health outcomes. As part of an ongoing longitudinal study, we investigated whether CC, as compared to being cared for by the parents at home, alters the composition of the gut microbiota, while accounting for known covariates of the infant gut microbiota. Stool samples of infants who entered CC (n=49) and control infants (n=49) were obtained before and four weeks after CC entrance. Using Redundancy analysis, Random Forests and Bayesian linear models we found that infant gut microbiota was not affected in a uniform way by entry to CC. In line with the literature, breastfeeding, birth mode, age, and the presence of siblings were shown to significantly impact the microbial composition.Peer reviewe

    Gravity wave activity in the lower atmosphere: Seasonal and latitudinal variations

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    A climatology of gravity wave activity in the lower atmosphere based on high-resolution radiosonde measurements provided by the Australian Bureau of Meteorology is presented. These data are ideal for investigating gravity wave activity and its variation with position and time. Observations from 18 meteorological stations within Australia and Antarctica, covering a latitude range of 12°S – 68°S and a longitude range of 78°E – 159°E, are discussed. Vertical wavenumber power spectra of normalized temperature fluctuations are calculated within both the troposphere and the lower stratosphere and are compared with the predictions of current gravity wave saturation theories. Estimates of important model parameters such as the total gravity wave energy per unit mass are also presented. The vertical wavenumber power spectra are found to remain approximately invariant with time and geographic location with only one significant exception. Spectral amplitudes observed within the lower stratosphere are found to be consistent with theoretical expectations but the amplitudes observed within the troposphere are consistently larger than expected, often by as much as a factor of about 3. Seasonal variations of stratospheric wave energy per unit mass are identified with maxima occurring during the low-latitude wet season and during the midlatitude winter. These variations do not exceed a factor of about 2. Similar variations are not found in the troposphere where temperature fluctuations are likely to be contaminated by convection and inversions. The largest values of wave energy density are typically found near the tropopause.Simon J. Allen and Robert A. Vincen

    More green, less lonely? A longitudinal cohort study.

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    BACKGROUND: Urban greening may reduce loneliness by offering opportunities for solace, social reconnection and supporting processes such as stress relief. We (i) assessed associations between residential green space and cumulative incidence of, and relief from, loneliness over 4 years; and (ii) explored contingencies by age, sex, disability and cohabitation status. METHODS: Multilevel logistic regressions of change in loneliness status in 8049 city-dwellers between 2013 (baseline) and 2017 (follow-up) in the Household, Income and Labour Dynamics in Australia study. Associations with objectively measured discrete green-space buffers (e.g. parks) (30% green space, respectively. Compared with the 30% green space, respectively. These associations were stronger again for people living alone, with 10-20% (OR = 0.608, 95% CI = 0.448 to 0.826), 20-30% (OR = 0.649, 95% CI = 0.436 to 0.966) and >30% (OR = 0.480, 95% CI = 0.278 to 0.829) green space within 1600 m. No age, sex or disability-related contingencies, associations with green space within 400 or 800 m or relief from loneliness reported at baseline were observed. CONCLUSIONS: A lower cumulative incidence of loneliness was observed among people with more green space within 1600 m of home, especially for people living alone. Potential biopsychosocial mechanisms warrant investigation

    Multi-Layer Evolution of Acoustic-Gravity Waves and Ionospheric Disturbances Over the United States After the 2022 Hunga Tonga Volcano Eruption

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    e Hunga-Tonga Hunga-Ha\u27apai volcano underwent a series of large-magnitude eruptions that generated in the atmosphere. We investigate the spatial and temporal evolutions of fluctuations driven by atmospheric acoustic-gravity waves (AGWs) and, in particular, the Lamb wave modes in high spatial resolution data sets measured over the Continental United States (CONUS), complemented with data over the Americas and the Pacific. Along with \u3e800 barometer sites, tropospheric observations, and Total Electron Content data from \u3e3,000 receivers, we report detections of volcano-induced AGWs in mesopause and ionosphere-thermosphere airglow imagery and Fabry-Perot interferometry. We also report unique AGW signatures in the ionospheric D-region, measured using Long-Range Navigation pulsed low-frequency transmitter signals. Although we observed fluctuations over a wide range of periods and speeds, we identify Lamb wave modes exhibiting 295–345 m s−1 phase front velocities with correlated spatial variability of their amplitudes from the Earth\u27s surface to the ionosphere. Results suggest that the Lamb wave modes, tracked by our ray-tracing modeling results, were accompanied by deep fluctuation fields coupled throughout the atmosphere, and were all largely consistent in arrival times with the sequence of eruptions over 8 hr. The ray results also highlight the importance of winds in reducing wave amplitudes at CONUS midlatitudes. The ability to identify and interpret Lamb wave modes and accompanying fluctuations on the basis of arrival times and speeds, despite complexity in their spectra and modulations by the inhomogeneous here, suggests opportunities for analysis and modeling to understand their signals to constrain features of azardous events

    Efficacy of psychosocial intervention in patients with mild Alzheimer's disease:the multicentre, rater blinded, randomised Danish Alzheimer Intervention Study (DAISY)

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    Objective To assess the efficacy at 12 months of an early psychosocial counselling and support programme for outpatients with mild Alzheimer’s disease and their primary care givers. Design Multicentre, randomised, controlled, rater blinded trial. Setting Primary care and memory clinics in five Danish districts. Participants 330 outpatients with mild Alzheimer’s disease and their 330 primary care givers. Interventions Participating dyads (patient and primary care giver) were randomised to control support during follow-up or to control support plus DAISY intervention (multifaceted and semi-tailored counselling, education, and support). Main outcome measures Primary outcomes at 12 months for patients were change from baseline in mini mental state examination (MMSE) score, Cornell depression scale score, and proxy rated European quality of life visual analogue scale (EQ-VAS) score. For care givers, outcomes were change from baseline in geriatric depression scale (GDS 30 items) score and EQ-VAS score. Results Because of multiple testing, statistical significance was set at an adjusted P limit of <0.0005. At 12 months there were no significant differences between the two allocation groups in changes from baseline in the primary and secondary outcomes. However, although non-significant with the adjusted P limit, a small difference was observed for one of the primary patient outcomes (Cornell depression scale score) in patients in favour of the DAISY intervention group before and after adjusting for attrition (P=0.0146 and P=0.0103 respectively). Conclusions The multifaceted, semi-tailored intervention with counselling, education, and support for patients with mild Alzheimer’s disease and their care givers did not have any significant effect beyond that with well structured follow-up support at 12 months after adjustment for multiple comparisons. The small positive effect found in the unadjusted primary outcome addressing depressive symptoms in patients may call for further research focusing on patients with Alzheimer’s disease and comorbid depression. Trial registration ISRCTN74848736

    Imaging gravity waves in lower stratospheric AMSU-A radiances, Part 2: Validation case study

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    Two-dimensional radiance maps from Channel 9 (~60&ndash;90 hPa) of the Advanced Microwave Sounding Unit (AMSU-A), acquired over southern Scandinavia on 14 January 2003, show plane-wave-like oscillations with a wavelength &lambda;<sub><i>h</i></sub> of ~400&ndash;500 km and peak brightness temperature amplitudes of up to 0.9 K. The wave-like pattern is observed in AMSU-A radiances from 8 overpasses of this region by 4 different satellites, revealing a growth in the disturbance amplitude from 00:00 UTC to 12:00 UTC and a change in its horizontal structure between 12:00 UTC and 20:00 UTC. Forecast and hindcast runs for 14 January 2003 using high-resolution global and regional numerical weather prediction (NWP) models generate a lower stratospheric mountain wave over southern Scandinavia with peak 90 hPa temperature amplitudes of ~5&ndash;7 K at 12:00 UTC and a similar horizontal wavelength, packet width, phase structure and time evolution to the disturbance observed in AMSU-A radiances. The wave&apos;s vertical wavelength is ~12 km. These NWP fields are validated against radiosonde wind and temperature profiles and airborne lidar profiles of temperature and aerosol backscatter ratios acquired from the NASA DC-8 during the second SAGE III Ozone Loss and Validation Experiment (SOLVE II). Both the amplitude and phase of the stratospheric mountain wave in the various NWP fields agree well with localized perturbation features in these suborbital measurements. In particular, we show that this wave formed the type II polar stratospheric clouds measured by the DC-8 lidar. To compare directly with the AMSU-A data, we convert these validated NWP temperature fields into swath-scanned brightness temperatures using three-dimensional Channel 9 weighting functions and the actual AMSU-A scan patterns from each of the 8 overpasses of this region. These NWP-based brightness temperatures contain two-dimensional oscillations due to this resolved stratospheric mountain wave that have an amplitude, wavelength, horizontal structure and time evolution that closely match those observed in the AMSU-A data. These comparisons not only verify gravity wave detection and horizontal imaging capabilities for AMSU-A Channel 9, but provide an absolute validation of the anticipated radiance signals for a given three-dimensional gravity wave, based on the modeling of Eckermann and Wu (2006)
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