Clinical and analytical follow‐up of 25 persons exposed accidentally to beryllium†

An accidental exposition of 25 persons to beryllium dust was used to follow up trace analytical and clinical parameters over a period of 10 months. Although no exposed person shows any symptoms of an acute beryllium intoxication, up to 5‐fold increased beryllium concentrations could be analysed in serum samples about 10 hours after exposition. The beryllium clearance shows a biological half time in the range of 2 to 8 weeks. The beryllium determination in the nanogram range was carried out using a combined method by flameless a.a.s. with a detection limit of 0.6 ppb Be and a relative standard deviation from 20 to 4% in relation to the concentration range of beryllium measurement.

Beryllium analyses are completed by thorax X‐ray, spirometry, y‐globulins and liver enzymes (SGOT, SGPT), which have shown no pathological values. Because it is known for beryllium to sensitize the cellular immune response, neopterin measurement was used to determine the activity of the immune system. Neopterin, a pteridine synthesized by activated macrophages after stimulation by gamma‐interferon derived from sensitized T‐lymphocytes, was determined in urine samples by HPLC combined with an fluorescence detector. Only in two cases a slight increase of neopterin has been found. As a result of this study it can be summarized, that a short‐time exposure to beryllium (10–20 h), which results in a increase of beryllium in serum to the fivefold normal beryllium level, does not initiate any symptoms of an acute beryllium intoxication. The exposed persons are controlled in future to evaluate the further course.     

Selective cellular and molecular effects of beryllium on lymphocytes†

An involvement of the immune system has been implicated in many of the whole animal effects of beryllium (Be) and its compounds and thus lymphocytes are a relevant cell model to study some of the cellular and molecular actions of the metal. Recent results indicate micromolar concentrations of Be salts are weakly mitogenic to lymphocytes in vitro probably as a result of direct interactions with the cell membranes. Furthermore evidence has been obtained that high affinity lymphocyte Be‐binding may be predictive of the potential to express delayed Be hypersensitivity in vivo. Although sub mitogenic concentrations of Be salts may actually activate accessory (macrophage type) cells, concentrations normally mitogenic to lymphocytes were found to inhibit their proliferative response to accessory cell dependent mitogens as a result of a Be²⁺ concentration dependent destruction of the adherent cell population. Higher concentrations of Be salts proved cytostatic to lymphocytes possibly by the established property of intracellularly accumulated Be²⁺ to inhibit cell division. Lymphocyte proliferation can be related to increases in protein phosphoryl‐ation capacity which in vitro can be inhibited by Be²⁺ and preliminary evidence indicates that tyrosine phosphorylation may be particularly sensitive.     

The international register of potentially toxic chemicals (IRPTC) its databank and network partners∗

The IRPTC was established by UNEP in 1976, upon the recommendation of the United Nations Conference on the Human Environment held in Stockholm in 1972.

It consists of a central unit and a network for information exchange. The main objective of IRPTC is to provide information adequate for the assessment of the hazards to health and the environment posed by chemicals. It is designed primarily to assist authorities responsible for protection of human health and the environment; however, its services are available to everyone.     

Cesium inhibition of motor activity in comparison to Lithium and Rubidium †

The biochemical and toxicological significance of cesium is scarcely understood, and could be evaluated in comparison with lithium widely used as a psychotropic drug. Two male Wistar rat groups of 200–220 g are administered independently, lithium, sodium, rubidium and cesium chloride, in doses of 3mEq/Kg/day (0.024 Eq/L drinking water) during 29 days. Motor activity was measured after the injection of 70 mg pargyline/Kg animal i.p. as inhibitor of MAO A + B with an activimeter of Tedeschy type. Accumulative movements per minute are presented in function of time. Total brain proteins, alkaline and acid phosphatases and blood parameters, haematocrit, haemoglobin and erythrocytes, were determined.

The maximal increase of motor activity was seen in rats treated with RbCl 2 h after the pargyline administration and the diminution was Rb>Li>Cs. Cesium induced a decrease of the total serum protein concentration from 6.39 ± 0.1 to 5.8±0.5mg/100ml serum in controls. Acid and alkaline phosphatase were decreased in cesium treated rats. The three determined blood parameters, haematocrit, haemoglobin and erythrocytes, show also a decrement with cesium treatment compared to the control ones.     

The application of analytical techniques to the understanding of chemical processes occurring in the atmosphere†

The science of atmospheric chemistry has expanded enormously over the last decade. In the stratosphere it has become apparent that small traces of a number of gases can perturb the earth's ozone layer. In the troposphere it is now realised that a general oxidation process is occurring which involves several free radicals and a large number of stable gaseous molecules containing the elements H, C, N, O, S, P, F, Cl, Br and I. In areas close to centres of large population this leads to the phenomenon of photochemical smog and in more remote areas it leads to excess acidity in rainwater.

In order to gain information on these problems and understand the underlying causes, many new analytical techniques have been developed. These are based mostly on chemilu‐minescence, laser spectroscopy, gas chromatography and mass spectrometry. Some examples of the application of these techniques will be given with emphasis placed on the role of GC/MS (gas chromatography combined with mass spectrometry).     

Potentiometric techniques applied to the modelling of actinide migration in natural water systems†

The utility of potentiometric techniques applied to environmental problems is discussed. The applicability of this technique to the estimation of thermodynamic quantities important for the modelling of uranium migration in natural waters is demonstrated. An experimental methodology for the determination of the UO₂(s) solubility product and the UO²⁺/U⁴⁺ redox potentials is proposed.     

The use of the embryo‐culture techniques in the research on the Teratogenic and Mutagenic properties of metals†

Actually, embryos can be cultured from the one‐cell stage up to the blastocyst stage, and their development can be easily monitored at any time: severe effects caused by toxic compounds are traduced by rapid embryonic death, less pronounced effects can be expressed by a lowered cleavage activity or by an arrest of the development from a particular stage. The system can be improved by transferring the embryos at the blastocyst stage in another more complete medium where they can “implant”; and form an inner cell mass with differentiated ectoderm and endoderm. Since last years, it has also become possible to culture postimplantation rodent embryos for short periods involving a number of particularly critical stages of organogenesis, such as the formation and closure of the anterior neuropore. Embryo‐culture also represents a useful system to study cytogenetic effects of chemicals which are often linked to lethal or teratogenic effects. These different possibilities are illustrated by examples of studies already performed with metals, and dealing with their teratogenic and/or cytogenetic effects on pre‐ and postimplantation rodents.     

Bioaccumulation of potentially toxic elements within the soil–plant system in Central Balkan region: analysis of the forest ecosystem capacity to mediate toxic elements

Environmental Geochemistry and Health - The accumulation of potentially toxic elements (PTEs) in terrestrial ecosystems has become a global concern, as PTEs may exert a wide range of negative...     

唐菖蒲对大气氟污染的生理生化反应(Physiological and Biochemical Responses of Gladiolus to Atmospheric Fluoride Pollution)

通过唐菖蒲在石家庄不同大气环境中叶片的形态、叶绿素总量、细胞膜透性以及过氧化物酶活性的变化,研究了唐菖蒲对氟污染胁迫的生理生化反应及适应调节机理.结果表明:石家庄市各监测点的大气中均存在氟污染,其污染物浓度由高到低依次为:市热电厂>元南小区>棉七生活区>阳光公园;从严重污染区到清洁区,随着污染程度的减小,唐菖蒲的叶绿素含量显著增加,细胞膜相对电导率及过氧化物酶活性明显降低.初步分析显示,唐菖蒲可作为大气氟污染的指示植物.     

Past predation risk induces an intertidal whelk (Nucella lamellosa) to respond to more dilute concentrations of its predator’s scent

Unless sensory control is coupled with developmental flexibility, organisms are unable to produce adaptive phenotypes in response to environmental risk cues. However, empirical examples of adaptive phenotypic plasticity focus largely on development and rarely on sensory control. Here, I ask whether past exposure to predation cues affects an intertidal whelk’s (Nucella lamellosa) sensitivity to the scent of a known predatory crab (Cancer productus). I pre-conditioned whelks for 30 days with the smell of crabs eating other whelks and then, after a period of rest (14 days in fresh seawater free of predator effluent), re-introduced them to different concentrations of waterborne crab scent. Relative to controls, pre-conditioned whelks expressed crab-defences at significantly lower concentrations of crab effluent, suggesting the pre-conditioning reduced their risk–response threshold. Results remind us that the full scope of factors controlling adaptive phenotypic plasticity in natural populations remains underappreciated.     

Evolution characteristics and transcriptional responses to multiple stresses of NAC genes in Chenopodium quinoa and its ancestral diploid species北大核心CSCD

NAC是一类广泛参与调控植物在生物和非生物胁迫下防御应答的转录因子.基于系统的比较基因组学研究方法,对藜麦Chenopodium quinoa的NAC基因进行进化与多个生物和非生物逆境下的应答研究.在藜麦C.quinoa、祖先二倍体Chenopodium pallidicaule和Chenopodium suecicum基因组中分别共鉴定得到106、54和54个NAC基因.染色体定位数据表明藜麦基因组中18个NAC基因涉及串联倍增事件.3个物种NAC基因的系统进化树证明藜麦基因组中存在NAC基因的倍增与丢失.藜麦分别和C.pallidicaule和C.suecicum之间同源基因组模块的对应数目关系进一步证明藜麦保留了相当数量的祖先二倍体NAC基因,是其NAC基因倍增的主要动力.此外,藜麦NAC基因在干旱、高温、盐、低磷胁迫和GCFSV侵染下的表达模式被阐明;大量NAC基因被显著地诱导表达,推测其参与了藜麦在生物和非生物胁迫下的防御应答反应.本研究结果为藜麦的遗传育种提供了优良的候选NAC基因.(图7参26)     

Determining the tourism potential of the Altındere Valley National Park (Trabzon/Turkey) with respect to its conservation value

This study was conducted to determine the tourism potential of Alt?ndere Valley National Park with respect to its conservation and utilization. With its natural values, Alt?ndere Valley National Park is one of the internationally prominent areas of potential for the recreational and touristic facilities it offers.

A mathematical method – criterion referenced method – was applied within this study, which was done to portray the touristic potential (resulting from the touristic and recreational utilization of the national park area and recreational zone) of the national park, which was visited by an average of 200,000 local and foreign guests.

According to this method, the conservation and utilization values that appear on two opposite axes were examined in accordance with the natural resource values of the area, and conservation and utilization values for each criterion were determined. Depending on the data, the general exploitable touristic potential of the area was specified.

A survey study was conducted on groups from various disciplines and local & foreign tourists visiting the area in specifying the touristic potential of the National Park. Eleven criteria were defined concerning the area and a criterion reference was prepared for each criterion. Then, conservation and utilization values for each criterion and exploitable touristic potential were mathematically indicated. The fact that the attained values were reduced to a percentage basis provides the opportunity to compare the researched area to similar fields that use the same method. Within the scope of the method, several suggestions were made using the information obtained in the evaluation of the data for every other source value.     

Characteristics of N2O emission from Medicago sativa stands and its response to nitrogen fertilizers in the Longdong dryland Plateau北大核心CSCD

Nitrous oxide (N2O) is one of the potent greenhouse gases (GHG) that depletes the stratospheric ozone. Nitrogen fertilizers are considered to be a major source of nitrous oxide (N2O) emissions from arable soils. To investigate the characteristics of N2O emission, its influencing factors, and its response to nitrogen application in dry grassland in the Loess Plateau, one of the most intensively used agricultural regions in China, we conducted a field trial with two treatments including N0 (0 kg hm-2) and N150 (150 kg hm-2) at the Qingyang Loess Plateau grassland agricultural research station of Lanzhou University. An LGR-N2O/CO gas analyzer was used to monitor the emissions. The results showed that the N2O fluxes of the N0 and N150 treatments during the monitoring period were -0.0036 and 0.0118 mg m-2 h-1, respectively; the flux in case of the N150 treatment was significantly higher than that for the N0 treatment. The N2O emission flux has a distinct diurnal variation characteristic, which first showed the trend of decreasing and then increasing. Regression analysis indicated a significant positive correlation between the N2O flux and the surface soil water content at a depth of 10 cm. The N2O emission flux increased by 131.3%, compared with that during the non-precipitation days. At the same time, the N2O emission flux showed a trend of decreasing with the increase of the surface soil temperature at a depth of 10 cm. The daily emission characteristics indicated that there may be a significant underestimation of the N2O flux at the daily or longer time-scale, based on the N2O flux value measured at 9:00-11:00. In summary, the N2O emissions from the sown alfalfa grassland of the eastern Gansu are strongly affected by precipitation and nitrogen application and have obvious daily dynamic characteristics. It is recommended that the accuracy and representativeness of N2O emission flux data be enhanced by continuous dynamic measurement using the instrument. © 2018 Science Press. All rights reserved.     

Why did the project fail to achieve its objectives in some villages? The experience of the Upland Settlement Project (USP) in Bangladesh

By sampling an upland settlement project (USP) village, this study examined why the project failed to achieve the planned objectives in some villages, and what livelihood strategies villagers (planters) have adopted to sustain their livelihoods. The paper uses data obtained by qualitative and quantitative methods. The USP was formulated with the objectives of settling 50 landless and marginal tribal families in a project village and introducing agroforestry and rubber plantations for short- and long-term socioeconomic development of planters, in a participatory manner. There are now only 15 planters in the project village and, although agroforestry has progressed well, only 30 to 40% of poor quality rubber trees remain. Planter participation in project activities was limited to wage labour, indicating that the USP failed to adequately achieve all its proposed objectives. In the face of project failure, planters have adopted diversified strategies to maintain their livelihoods. Several shortcomings caused failure of the project, such as the inability of project staff members to organize planters, failure to create awareness among planters about project benefits, lack of regular project money disbursement, sociocultural ignorance, and lack of social capital among planters. Recommendations are made for securing effective participation of local people to assure successful and sustainable project outcomes. Lessons learned will be helpful in formulating future development programmes in this country and elsewhere.     

Survival of microscopic stages of a perennial kelp (<Emphasis Type="Italic">Macrocystis pyrifera</Emphasis>) from the center and the southern extreme of its range in the Northern Hemisphere after exposure to simulated El Niño stress

Many organisms survive stressful conditions through a tolerant life history stage. The life history known as the alternation of generations is typical of temperate kelps, producing diploid macroscopic stages, and both haploid and diploid microscopic stages, with the haploid stages thought to be stress tolerant. The survival of microscopic stages of the giant kelp Macrocystispyrifera during El Niño has been suggested, yet has never been tested. This mechanism could be critical for population persistence, particularly at the southern limit of the range in the Northern Hemisphere, which is greatly impacted by El Niño conditions. The purpose of this study was to determine if microscopic stages of giant kelp could survive and recover from El Niño-type conditions and whether those from a population near its southern limit were more tolerant than a population at the center of its range. Microscopic stages were exposed to a laboratory simulation of potential El Niño conditions (high temperature, with and without light and nitrate) for 8 weeks and then allowed to recover at optimal conditions (low temperature and high nitrate) for 8 weeks, while controls were left at optimal conditions the entire 16 weeks test period. Haploid developmental stages from both populations survived and recovered from stressful conditions with no population level effect, suggesting haploid stress-tolerance may be widespread. The more advanced the developmental stage, and the presence of nitrate, resulted in significantly greater recovery for haploids. Yet, none of these stages were able to go on to produce sporophytes, whereas all controls did. There was a large population-level effect for diploids, however, with only microscopic diploid stages (embryonic sporophytes) from the southern-limit population recovering from El Niño simulated stress, suggesting ecotypic adaptation for microscopic sporophytes. Diploid recovery was significantly greater with light. We propose that the diploid stage is the most likely to survive and recover after El Niño conditions, as it would avoid obligate egg and sperm encounters after the stress period. The survivorship of the microscopic diploid in a seed bank analogue may be how the isolated southern-limit populations are able to recover after mass disappearance during El Niño.