Influence of water pollution on the growth and pigment concentration of the microalgae <Emphasis Type="Italic">Phaeodactylum tricornutum</Emphasis> Bohlin (Bacillariophyta)

The aim of the work was to study the influence of the water taken from one of the most polluted parts of the Peter the Great Bay (the Japan Sea), the Nakhodka Bay, on the growth and chlorophyll a concentration in the cells of microalga P. tricornutum Bohlin (Bacillariophyta). The estimation of the dynamics of cell number growth and chlorophyll a concentration in the cells of microalga grown in the water from the Nakhodka Bay was made. At the same time, in 2007–2008, the main hydrochemical parameters, such as water salinity, dissolved oxygen concentration, BOD₅, organic and mineral phosphates concentration, anionic surfactants, and total petroleum hydrocarbons, were determined. It is shown that in July 2007, when most hydrochemical parameters were lower than the maximum permissible level, the culture growth and chlorophyll a contents in the cells did not differ from the control for certain. In other seasons these indices differed greatly from the control. The positive correlation between the concentration of dissolved oxygen, phosphates, petroleum hydrocarbons, and the number of microalga cells, grown in the water from the Nakhodka Bay, was shown.     

水葫芦在污染水体修复中的应用

利用水葫芦分别修复受重金属和有机物污染的水体,结果显示,污水中铅和铜共存时,水葫芦对铅的吸附性较高,平均去除率达到75.53%,而对铜的去除率只有23.44%;在对受有机物污染水体的试验中发现,水葫芦对化学需氧量去除率达到了86.6%。试验结果表明,水葫芦对受重金属和有机物污染的水体都有较好的修复能力。     

Prenatal assessment of pulmonary vasculature development in fetuses with congenital diaphragmatic hernia: A literature review

Pathophysiological studies have shown that pulmonary vascular development is impaired in fetuses with a congenital diaphragmatic hernia (CDH), leading to a simplified vascular tree and increased vascular resistance. Multiple studies have described prenatal ultrasound parameters for the assessment of the pulmonary vasculature, but none of these parameters are used in daily clinical practice. We provide a comprehensive review of the literature published between January 1990 and February 2022 describing these parameters, and aim to explain the clinical relevance of these parameters from what is known from pathophysiological studies. Prenatal detection of a smaller diameter of the contralateral (i.e. contralateral to the diaphragmatic defect) first branch of the pulmonary artery (PA), higher pulsatility indices (PI), higher peak early diastolic reverse flow values, and a lower vascularization index seem of added value for the prediction of survival and, to a lesser extent, morbidity. Integration within the routine evaluation is complicated by the lack of uniformity of the methods used. To address the main components of the pathophysiological changes, we recommend future prenatal studies in CDH with a focus on PI values, PA diameters and pulmonary vascular branching.     

Effects of Ergorest® Arm Supports on Muscle Strain and Wrist Positions During the Use of the Mouse and Keyboard in Work With Visual Display Units: A Work Site Intervention

The effects of Ergorest^® arm supports on wrist angles and musculoskeletal strain in the neck-shoulder-arm region and electrical activity in the shoulder and arm muscles were studied during typing or the use of the mouse in work with a visual display unit (VDU). Twenty-one women were randomized into 3 groups (1 arm support, 2 arm supports, and control). Measurements were carried out before and after the 6-week intervention. The wrist extension of the mouse hand, the muscle activity of the trapezius muscle, and the subjective discomfort ratings indicated that 2 arm supports were better than 1 in work with a mouse. The Ergorest^® arm support alleviates muscle and joint strain in VDU work when used for both arms.     

Use of magnesia for boron removal from irrigation water

The risk of B phytotoxicity due to high levels of B in irrigation water can be avoided by removing B from the water, before its use, through adsorption on certain adsorbents, such as magnesia (industrial MgO), if the latter can be proven to be an effective and easy to handle means for B removal. In addition, if such a material is applied as a fertilizer after its use and the adsorbed B is easily released into the soil solution, B phytotoxicity could constitute a potential hazard. The objectives of this work were to: (a) establish the optimum working conditions (equilibration time, solution to adsorbent ratio, and particle size of the adsorbent) for B adsorption, (b) assess the magnitude of B adsorption by magnesia, both in capacity and intensity terms, as well as the influence of temperature, (c) study B desorbability from magnesia, spiked with B at two rates, 5 and 0.5 mg g(-1), and (d) compare the results from b and c to those obtained using reagent grade MgO. The results showed that the time to achieve equilibrium depended on the B concentration of the external solution and ranged from 6 h (for B /= 50 mg L(-1)). The percentage of B adsorbed decreased as the volume of external solution to adsorbent increased and a working ratio of 50:1 was selected. For magnesia, B adsorption was particle size dependent with the smallest fraction (<0.1 mm) sorbing more B than the other three fractions studied (0.1-1.0, 1.1-2.0, 2.1-4.0 mm). Boron adsorption was conducted under strongly alkaline pH (10.3 +/- 0.2 and 10.4 +/- 0.1 for the reagent and magnesia, respectively) and increased with temperature. Both adsorbents exhibited a high B adsorption capacity (Langmuir maximum values were 5.85 +/- 0.39 and 4.45 +/- 1.31 mg B g(-1) for the reagent and magnesia, respectively) comparable to other metal oxides. However, the reagent grade MgO seemed to be superior to magnesia in terms of capacity and strength of B retention. This superiority of the reagent was attributed to its greater surface area (34.7 compared with 5.8 m(2) g(-1) for magnesia) and to its conversion to Mg(OH)(2) during the adsorption process, whereas magnesia remained unaltered, as was evident from X-ray diffractograms. Based on this data, magnesia seems to be an effective means for removing excess B from irrigation water, particularly if a material of fine particle size is used. Boron desorbability after 240 h of desorption time was more pronounced for magnesia reaching up to 55 and 60% of the amount of B added, at the spiked rates of 5 and 0.5 mg g(-1), respectively. Although these figures indicate that approximately half of the amount of B added remained adsorbed, they cannot be easily extrapolated to field conditions, and if B-laden magnesia is applied to soils, the possibility of B phytotoxicity cannot be excluded.     

Prenatal detection of free sialic acid storage disease: genetic and biochemical studies in nine families

Sialic acid storage disorders, Salla disease (SD) and a severe infantile form of disease (ISSD), are recessively inherited allelic lysosomal storage disorders due to impaired egress of free sialic acid from lysosomes. Fourteen pregnancies at risk of adult-type free sialic acid storage disease, SD, were monitored by sialic acid assays, genetic linkage or mutation detection analyses using chorionic villus samples. Three affected and 12 unaffected fetuses were identified. The first studies were based on the sialic acid assays alone, but the location of the gene enabled the use of genetic linkage analysis and, more recently, the identification of the SLC17A5 gene and disease-causing mutations added yet another possibility for prenatal studies. A missense mutation 115C→T (R39C) is present in 95% of all Finnish SD alleles, providing an easy and reliable means of diagnostic studies. Both molecular and biochemical (sialic acid assay) studies can be used for prenatal diagnosis of free sialic acid storage diseases. Copyright © 2001 John Wiley & Sons, Ltd.     

Stability of acoustic individuality in the alarm calls of wild yellow ground squirrels Spermophilus fulvus and contrasting calls from trapped and free-ranging callers

The questions of individuality and stability of cues to identity in vocal signals are of considerable importance from theoretical and conservation perspectives. While individuality in alarm calls has been reported for many sciurids, it is not well-documented that the vocal identity encoded in the alarm calls is stable between different encounters with predators. Previous studies of two obligate hibernating rodents, speckled ground squirrels Spermophilus suslicus, and yellow ground squirrels Spermophilus fulvus demonstrated that, after hibernation, most individuals could not be identified reliably by their alarm calls. Moreover, in most speckled ground squirrels, individual patterns of alarm calls changed progressively over as little as 2 weeks. However, these previous data have been obtained using the collection of alarm calls from trapped animals. Here, we examined ten free-ranging dye-marked yellow ground squirrels to determine whether their alarm calls retain the cues to individuality between two encounters of surrogate predators (humans), separated on average by 3 days. Discriminant function analysis showed that the alarm calls of individual yellow ground squirrels were very similar within a recording session, providing very high individual distinctiveness. However, in six of the ten animals, the alarm calls were unstable between recording sessions. Also, we examined ten dye-marked individuals for consistency of acoustic characteristics of their alarm calls between the encounters of humans, differing in techniques of call collection, from free-ranging vs trapped animals. We found differences only in two variables, both related to sound degradation in the environment. Data are discussed in relation to hypotheses explaining the adaptive utility of acoustic individuality in alarm calls.     

Nitrate leaching under vegetable field above a shallow aquifer in Slovenia

In the search for new technologies that would ensure optimum yield and environmental sustainability, various irrigation, nitrogen and cropping system management strategies for the production of vegetables with a shorter growing period were assessed at a benchmark site in Slovenia for the years 2006 and 2007. In the studied years four irrigation and fertilization treatments were applied: (1) 50% drip irrigation of plants water requirements ET_crop and the farmer's practice of fertilisation (broadcasting), (2) fertilisation and 100% drip irrigation (fertigation), (3) the farmer's practice of irrigation (sprinkler irrigation using water stored in plastic tanks) and fertilisation, and (4) control (the farmer's practice of irrigation but no fertilisation). An equivalent of 80, 80 and 200 kg ha⁻¹ of nitrogen (N), 50, 50 and 80 kg ha⁻¹ of phosphorous (P) and 120, 120 and 300 kg ha⁻¹ of potassium (K) was added for iceberg lettuce, endive and cabbage, respectively. Nitrogen (N) labelled fertilizer (¹⁵N) was applied to trace the movement of the applied N fertiliser. The tested irrigation and fertilisation techniques for the production of vegetables with a shorter growing period in the Slovenian climate showed that environmentally sustainable practices (split application of nutrients compared to broadcast incorporating fertilisation) should be a practice of choice in water protection zones. The results confirm that fertigation and improved irrigation scheduling can be an effective way of minimizing nitrate leaching, and should be considered for vegetable production in or close to groundwater protection zones.     

An economic assessment of drought effects on three grassland systems in Switzerland

This paper analyzes the economic impacts of summer drought on Swiss grassland production. We combine field trial data from drought experiments in three different grasslands in Switzerland with site-specific information on economic costs and benefits. The analysis focuses on the economic implications of drought effects on grassland yields as well as grassland composition. In agreement with earlier studies, we found rather heterogeneous yield effects of drought on Swiss grassland systems, with significantly reduced yields as a response to drought at the lowland and sub-alpine sites, but increased yields at the wetter pre-alpine site. Relative yield losses were highest at the sub-alpine site (with annual yield losses of up to 37 %). However, because income from grassland production at extensive sites relies to a large extent on ecological direct payments, even large yield losses had only limited implications in terms of relative profit reductions. In contrast, negative drought impacts at the most productive, intensively managed lowland site were dominant, with average annual drought-induced profit margin reductions of about 28 %. This is furthermore emphasized if analyzing the farm level perspective of drought impacts. Combining site-specific effects at the farm level, we found that in particular farms with high shares of lowland grassland sites suffer from summer droughts in terms of farm-level fodder production and profit margins. Moreover, our results showed that the higher competitiveness of weeds (broad-leaved dock) under drought conditions will require increasing attention on weed control measures in future grassland production systems. Taking into account that the risk of drought occurrence is expected to increase in the coming years, additional instruments to cope with drought risks in fodder production and finally farmers’ income have to be developed.     

Flexible foraging strategies of gentoo penguins <Emphasis Type="Italic">Pygoscelis papua</Emphasis> over 5 years in the South Shetland Islands,Antarctica

Gentoo penguins Pygoscelis papua show considerable plasticity in their diet, diving, and foraging behaviors among colonies; we expected that they might exhibit similar variability over time, at a single site, since flexible foraging habits would provide a buffer against changes in prey availability. We examined interannual changes in the foraging strategies and diet of gentoo penguins in the South Shetland Islands, Antarctica, over 5 years with variable prey abundance. Antarctic krill Euphausia superba was the primary diet item, and fish the secondary, though the importance of these items varied among years. Diving behavior also varied over time: different dive depth distributions were observed among years. Nonetheless, chick-rearing success remained relatively constant, indicating that gentoo penguins were able to maintain chick provisioning by altering their foraging strategy among years. Variable abundance of krill in the region did not have observable impacts on the diet, foraging behaviors or chick-rearing success of gentoo penguins. We suggest that foraging plasticity may be one reason that gentoo penguin populations have remained stable in the region, while their congeners (P. antarctica and P. adeliae) with less flexible foraging strategies have declined.