The trophic link between squid and the emperor penguin <Emphasis Type="Italic">Aptenodytes forsteri</Emphasis> at Pointe Géologie,Antarctica

Cephalopod beaks retrieved from stomachs of dead emperor penguin chicks at Pointe Géologie, Terre Adélie, provide information on taxonomic and size composition of the penguin’s squid diet, on the trophic range of the squid species preyed upon and on the fractional trophic impact of the penguin on the whole food web. Emperor penguins prey upon four squid species (Psychroteuthis glacialis, Kondakovia longimana, Gonatus antarcticus, Alluroteuthis antarcticus) and do not take squid larger than 480 mm mantle length. Larger squid live either below the penguin’s diving range or are beyond its handling capacity. Nitrogen stable isotope ratios indicate that squids cover a range of about two trophic levels (2.5–8‰ δ¹⁵N). The impact of the emperor penguin, however, concentrates on the upper part of this range, about 68% of its squid prey being >6‰ δ¹⁵N. The principal components of the emperor’s diet, fish, krill and squid, differ distinctly in average trophic level. Consequently the trophic position of the emperor penguin changes accordingly with diet composition and may differ by almost one trophic level between different emperor penguin colonies.     

Oligohydramnios with amnio-chorionic separation at 15–16 weeks' gestation

Nine patients with oligohydramnios and amnio-chorionic separation were identified out of 7000 women who underwent a vaginal ultrasound examination at 15–16 weeks' gestation. Oligohydramnios was defined as a reduced amount of amniotic fluid, a distance of more than 1 cm between the chorion and amnion, and a good turgor of the amnion without floating membranes or intrauterine sheets. Fetal malformations were observed in all nine cases. In four of six fetuses where chromosomal analysis was available, an abnormal karyotype was found. It is concluded that oligohydramnios in the early second trimester is associated with fetal abnormality.     

Further Development of a Specific Conductivity Approach to Measure Groundwater Discharge Area within Lakes

Groundwater exchanges with most lakes are rarely quantified because there are many technical challenges to quantification. We investigated a lakebed mapping approach to infer the relative areas of groundwater exchange in 12 prairie shallow lakes and five Laurentian mixed forest shallow lakes in Minnesota, USA in 2011. We used a relatively common approach (seepage meters) to provide baseline information on the magnitude and direction of flow at four locations in each lake. To expand from point measurements to the whole‐lake scale, we explored use of specific conductivity as a cheaper and more time efficient proxy for groundwater discharge to lakes. We validated the approach at near shore stations in each lake where seepage meter measurements and specific conductivity surveys overlapped. Specific conductivity surveys provided a similar assessment of groundwater discharge compared to seepage meters for 50% of the lake‐sampling period combinations. The lakebed mapping approach, when validated for a lake with a limited number of seepage meter (or alternative methods) measurements, offers the advantages of being more time and labor efficient over the use of a similar number of seepage meter monitoring locations; seepage meters (or piezometers, for example) are costlier in terms of equipment and labor, even for single‐lake studies. We show the combined approach could provide useful baselines for understanding and mapping groundwater exchange in shallow lakes.     

HPLC-MS/MS in der Rückstandsanalytik von Pflanzenschutzmitteln

Goal and Scope

Increasing demands from the regulatory authorities of plant protection products for residue analytical methods on the one hand and the need for cost reduction by shorter development times on the other hand have led to a significant displacement of conventional methods (e.g. HPLC-UV or GC-MS) by HPLC-MS/MS with atmospheric pressure ionization (API) in residue analysis since the mid of the 1990s. This development started in the pharmaceutical industries where HPLC-MS/MS had already been used for the quantitation of drugs and their metabolites in plasma since the late 1980s.

Methods

The reason for the high acceptability of HPLC-MS/MS with electrospray ionisation (ESI) or chemical ionization at atmosheric pressure (APCI) compared with alternative methods are shown with respect to analytical quality parameters, compliance with international registration guidelines and economic reasons.

Results and Conclusion

HPLC-MS/MS is being applied for solving ca. 75% of all analytical problems occuring in modern residue analytical laboratories. This technique offers convincing advantages for the determination of plant protection products and their metabolites in various matrices. These are a reduced number of or no clean-up steps after extraction of the samples, high throughput besides high ruggedness, low limits of detection and a large linear measuring range. In addition, several analytes of various chemical classes can be determined within one chromatographic run. Due to the high selectivity there is only little need for additional confirmatory methods. For enforcement purposes HPLC-MS/MS is accepted by the European authorities since 2002. However, due to high costs for instrumentation and specially skilled personnel only few enforcement laboratories have invested into this technology, so far.

Recommendation and Perspective

The importance of HPLC-MS/MS in residue analysis will further increase, as new ionization techniques will enable the analysis of more analytes and as the investment costs will decrease in the future. However, proven conventional methods will still survive in some cases. New concepts, such as parallel HPLC-MS/MS or on-line purification of extracts by column switching which are already widely used in the pharmaceutical industry could help to further increase the throughput. However, for a sound evaluation with respect to their applicability in residue analysis there is so far too little experience.     

The Impact of Computers Upon Air Pollution Research

The electronic computer has had a profound effect upon air pollution research activities. This paper discusses some of the ways in which Public Health Service scientists routinely make use of the computer. It is used as a data processor to handle the large volumes of data resulting from continuous air monitoring devices. More importantly, it is used to perform the very complex computations involved in various statistical analyses and mathematical model building. In future years computers may be used on a real-time basis to control the sources which emit pollutants to the atmosphere.     

Part I: lead peroxide candles and dustfall collectors

A diffusion flame burner was operated to determine the effect of several parameters on the quantity of NO_x and unburned hydrocarbons produced. The statistical analysis indicated the unburned hydrocarbon emissions to be dependent upon the rate of heat release in the system, the amount of excess combustion air, the fuel molecular structure, and the interaction between the fuel structure and the amount of excess air. Analysis of the NO_x emissions, after an adjustment to a common temperature to eliminate the temperature effect, showed them to be dependent upon the fuel molecular structure and the amount of excess air. The NO_x emissions reached a maximum at the conditions which yielded minimum unburned hydrocarbon emissions. Multiple regressions were made which yielded predicting equations for both the unburned hydrocarbon and the NO_x for the apparatus used.     

Monitoring of the microbial community composition in saline aquifers during CO2 storage by fluorescence in situ hybridisation

This study reveals the first analyses of the composition and activity of the microbial community of a saline CO₂ storage aquifer. Microbial monitoring during CO₂ injection has been reported. By using fluorescence in situ hybridisation (FISH), we have shown that the microbial community was strongly influenced by the CO₂ injection. Before CO₂ arrival, up to 6 × 10⁶ cells ml⁻¹ were detected by DAPI staining at a depth of 647 m below the surface. The microbial community was dominated by the domain Bacteria that represented approximately 60% to 90% of the total cell number, with Proteobacteria and Firmicutes as the most abundant phyla comprising up to 47% and 45% of the entire population, respectively. Both the total cell counts as well as the counts of the specific physiological groups revealed quantitative and qualitative changes after CO₂ arrival. Our study revealed temporal outcompetition of sulphate-reducing bacteria by methanogenic archaea. In addition, an enhanced activity of the microbial population after five months CO₂ storage indicated that the bacterial community was able to adapt to the extreme conditions of the deep biosphere and to the extreme changes of these atypical conditions.