Search results for "LOOM"
showing 10 items of 78 documents
Use of the preliminary Jedlice Reservoir for water protection in the Turawa Reservoir on the Mała Panew River
2009
Abstract Physico-chemical variables of water quality and benthic community structure were assessed in order to evaluate the need for reinstating the use of the preliminary Jedlice Reservoir. The waters of the Mała Panew River carry a significant load of nutrient compounds, particularly nitrates and phosphates. Deteriorating water quality results in permanent algal blooms and changes in the macrofauna structure. It was confirmed that the use of a preliminary reservoir could contribute to the protection of the Turawa Dam Reservoir against pollutants transported by the waters of the Mała Panew River.
Long-term land-based and internal forcing of the nutrient state of the Gulf of Riga (Baltic Sea)
2004
Abstract The long-term nutrient trends (N, P, Si) in the Gulf of Riga and their driving factors were studied based on monitoring data from 1974 to 2000. Each nutrient showed individual temporal behaviour. The nitrate-N pool peaked in 1989–1990, but after that, the increasing trend switched to a decrease. The P pool, in turn, constantly increased till the mid-1990s; afterwards, a tendency was unclear. The obvious depletion of the silicate-Si pool reversed after 1995. Algal growth limitation responded to the changes in the nutrient pool. P deficiency during the vernal phytoplankton bloom in 1979–1990 switched to further alternate P or N limitation or co-limitation. Since 1991, Si shortage set…
Gross Primary Production and false spring: a spatio-temporal analysis
2020
<p>Phenological information can be obtained from different sources of data. For instance, from remote sensing data or products and from models driven by weather variables. The former typically allows analyzing land surface phenology whereas the latter provide plant phenological information. Analyzing relationships between both sources of data allows us to understand the impact of climate change on vegetation over space and time. For example, the onset of spring is advanced or delayed by changes in the climate. These alterations affect plant productivity and animal migrations.</p><p>Spring onset monitoring is supported by the Extended Spring Index (…
Welfare status of cage farmed European sea bass (Dicentrarchus labrax): A comparison between submerged and surface cages
2011
Abstract Submersible sea-cages represent an alternative method to standard surface-based cages, and could help solve several production problems that exist in surface-based farming, such as heavy storms, algal and jellyfish blooms and attacks by predators. In this study, we investigated growth, haematological, biochemical and immunological parameters of European sea bass ( Dicentrarchus labrax ) farmed in surface and submersible cages, to compare the physiological status under different rearing conditions. In addition, we evaluated the use of erythrocyte HSP70 levels as a biomarker of fish welfare. The study was conducted in two submerged and two surface cages filled with D. labrax . No sig…
Luminance and contrast in visual perception of time to collision.
2013
AbstractMany animals avoid dark, approaching objects seen against a lighter background but show no or weaker reactions to stimuli with inverted contrast. We investigated whether human observers would respond differently to such stimuli in terms of estimated time-to-arrival. We varied luminances of an approaching, light or dark disk and a plain, grey background, and for several conditions, continuously adjusted calibrations so as to keep contrast and/or overall lightness constant. Since no effects were found, we conclude that humans are able to discard luminance and contrast for the task at hand. Generally, however, performance was affected by different, consecutive regimes of feedback: Init…
Task Modifications in Walking Postpone Decline in Life-Space Mobility Among Community-Dwelling Older People: A 2-year Follow-up Study
2017
Background Task modification refers to performing a task differently than before. While task modification in walking may be a sign of looming walking difficulty, it may also be adaptive in and postpone the decline in life-space mobility. However, this has not been studied. This study examined whether changes in life-space mobility over a 2-year period differ between people who at baseline report no walking difficulty and no task modification, those who report no walking difficulty but task modification, and those who report walking difficulty. Methods Community-dwelling people aged 75–90 years were interviewed face-to-face at baseline (N = 848), and over phone one (n = 816) and two (n = 761…
Audiovisual Integration of Time-to-Contact Information for Approaching Objects.
2018
Previous studies of time-to-collision (TTC) judgments of approaching objects focused on effectiveness of visual TTC information in the optical expansion pattern (e.g., visual tau, disparity). Fewer studies examined effectiveness of auditory TTC information in the pattern of increasing intensity (auditory tau), or measured integration of auditory and visual TTC information. Here, participants judged TTC of an approaching object presented in the visual or auditory modality, or both concurrently. TTC information provided by the modalities was jittered slightly against each other, so that auditory and visual TTC were not perfectly correlated. A psychophysical reverse correlation approach was us…
Sunscreen Products as Emerging Pollutants to Coastal Waters
2013
A growing awareness of the risks associated with skin exposure to ultraviolet (UV) radiation over the past decades has led to increased use of sunscreen cosmetic products leading the introduction of new chemical compounds in the marine environment. Although coastal tourism and recreation are the largest and most rapidly growing activities in the world, the evaluation of sunscreen as source of chemicals to the coastal marine system has not been addressed. Concentrations of chemical UV filters included in the formulation of sunscreens, such as benzophehone 3 (BZ-3), 4-methylbenzylidene camphor (4-MBC), TiO2 and ZnO, are detected in nearshore waters with variable concentrations along the day a…
Loomis-Whitney inequalities in Heisenberg groups
2021
This note concerns Loomis-Whitney inequalities in Heisenberg groups $\mathbb{H}^n$: $$|K| \lesssim \prod_{j=1}^{2n}|\pi_j(K)|^{\frac{n+1}{n(2n+1)}}, \qquad K \subset \mathbb{H}^n.$$ Here $\pi_{j}$, $j=1,\ldots,2n$, are the vertical Heisenberg projections to the hyperplanes $\{x_j=0\}$, respectively, and $|\cdot|$ refers to a natural Haar measure on either $\mathbb{H}^n$, or one of the hyperplanes. The Loomis-Whitney inequality in the first Heisenberg group $\mathbb{H}^1$ is a direct consequence of known $L^p$ improving properties of the standard Radon transform in $\mathbb{R}^2$. In this note, we show how the Loomis-Whitney inequalities in higher dimensional Heisenberg groups can be deduced…
Toxic cyanobacterial blooms in reservoirs under a semiarid Mediterranean climate: the magnification of a problem
2007
Sicilian reservoirs constitute the most important water resources available on the island. During summer 2001, the intense water utilization of Lake Arancio reservoir reduced the water level significantly. This coincided with the formation of intense blooms formed by the microcystin-producing cyanobacterium Microcystis aeruginosa. During summer 2003, Lake Arancio was continuously filled and the vertical stratification of the water column was maintained, resulting in 5-6 fold lower cell numbers of Microcystis aeruginosa. For both years a significant linear relationship between microcystin net production and Microcysytis cell division was observed, implying that Microcystis cell numbers can b…