How is adaptation to climate change reflected in current practice of forest management and conservation? A case study from Germany

Climate change is expected to challenge forest management and nature conservation in forests. Besides forest species, strategies and references for management and conservation will be affected. In this paper, we qualitatively analysed whether forest conservation and management practice have already adapted to the impacts of climate change and to what extent those practices reflect the adaptation strategies dealt with in international peer-reviewed literature. To this end, we conducted thirteen in-depth interviews with forest practitioners (forest officers/forest district officers) in four regions in Germany. The interview regions were selected to represent the variation in tree species composition, forest ownership regimes and vulnerability to climate change. Although interviewees claimed to take climate change and adaptation strategies into account, in practice such strategies have as yet only occasionally been implemented. Our results suggest that strategies for adapting forest management to climate change are just in the early stages of development or supplement existing strategies relating to general risk reduction or nature-orientated forest management. The extent to which climate change adaptation strategies have influenced overall management varies. This variation and the lack of specific strategies also reflect the existing uncertainties about future changes in climate and about the capacity of forest ecosystems to adapt. We conclude that, in the face of climate change, forest management will have a major influence on future biodiversity composition of forest ecosystems. Hence, a framework for conservation in forests providing recommendations which also take into account the consequences of climate change needs to be developed.     

Minimizing hydrodynamic stress in mammalian cell culture through the lobed Taylor-Couette bioreactor

The objective of the present study was to investigate the effect of hydrodynamic stress heterogeneity on metabolism and productivity of an industrial mammalian cell line. For this purpose, a novel Lobed Taylor-Couette (LTC) mixing unit combining a narrow distribution of hydrodynamic stresses and a membrane aeration system to prevent cell damage by bubble bursting was developed. A hydrodynamic analysis of the LTC was developed to reproduce, in a uniform hydrodynamic environment, the same hydrodynamic stress encountered locally by cells in a stirred tank, particularly at the large scale, e.g., close and far from the impeller. The developed LTC was used to simulate the stress values near the impeller of a laboratory stirred tank bioreactor, equal to about 0.4 Pa, which is however below the threshold value leading to cell death. It was found that the cells actively change their metabolism by increasing lactate production and decreasing titer while the consumption of the main nutrients remains substantially unchanged. When considering average stress values ranging from 1 to 10 Pa found by other researchers to cause physiological response of cells to the hydrodynamic stress in heterogeneous stirred vessels, our results are close to the lower boundary of this interval.     

Gyrotaxis: A plume model for self-focusing micro-organisms

We consider the phenomenon of self-focusing pattern formation of motile micro-organisms (“streamer”). The focusing mechanism is based on gyrotaxis, a physical phenomenon, and it results from the balance between viscous and gravitational moments on the organisms. Under particular circumstances such streamers are stabilized and sink, resulting in vertical transport of micro-organisms as well as horizontal heterogeneity in cell concentration. We develop a plume model for the streamer, which consists of the equations of continuity, momentum, and cell concentration. These equations are further simplified to three basic equations representing volume, momentum and concentration fluxes of the steady-state plume. Asymptotic analytical solutions for the plume are obtained. From numerical solutions we find the shape of the plume which takes the form of a vertical string with lengths ranging from 1 to 10 cm. The streamer formation can be related to algal blooms occurring in the sea and to algal cultures grown in the laboratory.     

Maintenance of high-density lipoprotein blood levels prior to spontaneous abortion in pig-tailed macaques (Macaca nemestrina)

Blood was drawn throughout the first half of the pregnancies of 24 pig-tailed macaques (Macaca nemestrina) to evaluate longitudinal high-density lipoprotein (HDL) changes. In all 15 normal pregnancies, HDL decreased at least 50%; the mean value for the group fell from 0.45 gm/liter to 0.17 gm/liter. HDL began to fall after about four weeks of pregnancy. However, no comparable HDL change occurred in nine pregnancies that terminated in spontaneous abortions. This lack of an HDL decrease was unexpected. Subsequent studies showed that the predominant decrease was in the HDL₂ subfraction. The data indicate that the normal physiologic metabolism or utilization of HDL is aberrant early in pregnancies ending in spontaneous abortions and may be due to a dysfunctional fetal-placental unit.     

Relations among whole blood serotonin and sex,age, diet,and social status in Macaca nemestrina

Whole blood serotonin (WBS) determinations were made in 56 pigtailed macaques (Macaca nemestrina) with approximately equal numbers in three age groups: young-adult (4–5 years), middle-aged (13–14 years), and old (over 18 years). The animals were housed in ten living groups with one female and male of each age group in each living group. Half of the groups were fed a diet high in lipid, cholesterol, simple sugars, and sodium; the other half received a restricted diet. Three determinations per animal showed WBS levels to be stable at two times of day and at a 1-week interval, and individual differences were stable over several months' time. The mean WBS concentrations in M. nemestrina were found to be considerably higher than those reported for other species. The mean levels in females were almost 25% higher than in males. No significant effects of age, diet, or dominance status were detected.     

A general method for identification of polyhydroxyalkanoic acid synthase genes from pseudomonads belonging to the rRNA homology group I

Using a 30-mer oligonucleotide probe highly specific for polyhydroxyalkanoic acid (PHA) synthase genes, the respective genes of Pseudomonas citronellolis, P. mendocina, Pseudomonas sp. DSM 1650 and Pseudomonas sp. GP4BH1 were cloned from genomic libraries in the cosmid pHC79. A 19.5-kbp and a 22.0-kbp EcoRI restriction fragment of P. citronellolis or Pseudomonas sp. DSM 1650, respectively, conferred the ability to accumulate PHA of medium-chain-length 3-hydroxyalkanoic acids (HA _mcl ) from octanoate as well as from gluconate to the PHA-negative mutant P. putida GPp104. An 11.0-kbp EcoRI fragment was cloned from P. mendocina, which restored in GPp104 the ability to synthesize PHA from octanoate but not from gluconate. From Pseudomonas sp. GP4BH1 three different genomic fragments encoding PHA synthases were cloned. This indicated that strain GP4BH1 possesses three different functionally active PHA synthases. Two of these fragments (6.4 kbp and 3.8 kbp) encoded for a PHA synthase, preferentially incorporating hydroxyalkanoic acids of short chain length (HA _scl ), and the synthases were expressed in either GPp104 and Alcaligenes eutrophus H16-PHB^–4, respectively. The PHA synthase encoded by the third fragment (6.5 kbp) led to the incorporation of HA _mcl and was expressed in GPp104 but not in PHB^–4. Correspondence to: A. Steinbüchel     

Lipid composition of Trypanosoma cruzi.

1. Lipid composition of Trypanosoma cruzi epimastigote form in culture consist of 35% of phospholipids and 65% of neutral lipids. 2. Among the phospholipids, phosphatidylcholine is the more abundant (44%), followed by phosphatidylethanolamine (28%), phosphatidylinositol (12%), sphingomyelin (4%), and smaller amounts of cardiolipin, phosphatidic acid, lysolecithin, phosphatidylserine (traces), and an unidentified phospholipid (3%). 3. Pulse labeling with 32P showed highest specific incorporation in phosphatidylethanolamine, followed by phosphatidylinositol and phosphatidylcholine, suggesting a more active role for phosphatidylethanolamine in these organisms.