A comparison of the strength of biodiversity effects across multiple functions

In order to predict which ecosystem functions are most at risk from biodiversity loss, meta-analyses have generalised results from biodiversity experiments over different sites and ecosystem types. In contrast, comparing the strength of biodiversity effects across a large number of ecosystem processes measured in a single experiment permits more direct comparisons. Here, we present an analysis of 418 separate measures of 38 ecosystem processes. Overall, 45 % of processes were significantly affected by plant species richness, suggesting that, while diversity affects a large number of processes not all respond to biodiversity. We therefore compared the strength of plant diversity effects between different categories of ecosystem processes, grouping processes according to the year of measurement, their biogeochemical cycle, trophic level and compartment (above- or belowground) and according to whether they were measures of biodiversity or other ecosystem processes, biotic or abiotic and static or dynamic. Overall, and for several individual processes, we found that biodiversity effects became stronger over time. Measures of the carbon cycle were also affected more strongly by plant species richness than were the measures associated with the nitrogen cycle. Further, we found greater plant species richness effects on measures of biodiversity than on other processes. The differential effects of plant diversity on the various types of ecosystem processes indicate that future research and political effort should shift from a general debate about whether biodiversity loss impairs ecosystem functions to focussing on the specific functions of interest and ways to preserve them individually or in combination.     

Characterization of leptin intracellular trafficking

Leptin is produced by adipose tissue, and its concentration in plasma is related to the amount of fat in the body. The leptin receptor (OBR) is a member of the class I cytokine receptor family and several different isoforms, produced by alternative mRNA splicing are found in many tissues, including the hypothalamus. The two predominant isoforms includes a long form (OBR) with an intracellular domain of 303 amino acids and a shorter form (OBR) with an intracellular domain of 34 amino acids. Since OBR, is mainly expressed in the hypotalamus, it has been suggested to be the main signalling form. The peripheral production of leptin by adipocyte tissue and its effects as a signal of satiety in the central nervous system imply that leptin gains access to regions of the brain regulating in energy balance by crossing the blood-brain barrier. In an attempt to characterize the intracellular transport of leptin, we have followed binding internalization and degradation of leptin in HEK293 cells. We have also monitored the intracellular transport pathway of fluorescent conjugated leptin in HEK293 cells. Phenylarsine oxide, a general inhibitor of endocytosis, as well as incubation at mild hypertonic conditions, prevented the uptake of leptin, confirming a receptor-mediated internalization process. When internalized, 125I-leptin was rapidly accumulated inside the cells and reached a maximum after 10 min. After 70 minutes about 40-50% of total counts in each time point were found in the medium as TCA-soluble material. Leptin sorting, at the level of early endosomes, did not seem to involve recycling endosomes, since FITC-leptin was sorted from Cy3-transferrin containing compartments at 37 degrees C. At 45 minutes of continuos internalization, FITC-leptin appeared mainly accumulated in late endocytic structures colocalizing with internalized rhodamine coupled epidermial growth factor (EGF) and the lysosomal marker protein lamp-1. The transport of leptin was also shown to engage a monensin and bafilomycin sensitive degradation process in lysosomes. Together, our results provide novel data concerning the uptake, intracellular localization and transport of leptin.     

Flexible Ion‐Conducting Composite Membranes for Lithium Batteries

The use of metallic lithium anodes enables higher energy density and higher specific capacity Li‐based batteries. However, it is essential to suppress lithium dendrite growth during electrodeposition. Li‐ion‐conducting ceramics (LICC) can mechanically suppress dendritic growth but are too fragile and also have low Li‐ion conductivity. Here, a simple, versatile, and scalable procedure for fabricating flexible Li‐ion‐conducting composite membranes composed of a single layer of LICC particles firmly embedded in a polymer matrix with their top and bottom surfaces exposed to allow for ionic transport is described. The membranes are thin (<100 μm) and possess high Li‐ion conductance at thicknesses where LICC disks are mechanically unstable. It is demonstrated that these membranes suppress Li dendrite growth even when the shear modulus of the matrix is lower than that of lithium. It is anticipated that these membranes enable the use of metallic lithium anodes in conventional and solid‐state Li‐ion batteries as well as in future Li? S and Li? O₂ batteries.     

Spatial Hyperschematia without Spatial Neglect after Insulo-Thalamic Disconnection

Different spatial representations are not stored as a single multipurpose map in the brain. Right brain-damaged patients can show a distortion, a compression of peripersonal and extrapersonal space. Here we report the case of a patient with a right insulo-thalamic disconnection without spatial neglect. The patient, compared with 10 healthy control subjects, showed a constant and reliable increase of her peripersonal and extrapersonal egocentric space representations - that we named spatial hyperschematia - yet left her allocentric space representations intact. This striking dissociation shows that our interactions with the surrounding world are represented and processed modularly in the human brain, depending on their frame of reference.     

Evaluation of the 7-h membrane filter test for quantitation of fecal coliforms in water

The 7-h fecal coliform (FC) test for detection of FC organisms in water was evaluated to establish its validity and usefulness for emergency and disaster situations. The waters tested consisted of routine samples collected for public health surveillance and enforcement purposes. A total of 984 water samples from throughout California were assayed. These included samples from coastal salt waters, rivers, canals, and reservoirs, in addition to potable and miscellaneous freshwater sources. A portion of each sample was tested concurrently by both the 7-h FC test and the most-probable-number FC five-tube test. The 7-h FC test samples were incubated for 7 to 7.25 h at 41.5 degrees C. Overall, greater than 90% agreement was obtained between the methods in determining whether the water quality was acceptable or unacceptable. Statistical analysis of the 984 samples confirmed that the 7-h FC method was a suitable alternative to the most-probable-number FC method for evaluation of freshwater samples. During emergencies or disasters, the 7-h FC test could provide a means for detection of fecal contamination of water with results available in less than 1 day.     

Transmitting genetic risk information in families: attitudes about disclosing the identity of relatives.

Attitudes about disclosing the identities of family members to a physician to ensure diffusion of genetic risk information within affected families were examined in a questionnaire study of Danish patients with alpha1-antitrypsin deficiency (A1AD), their relatives, and a control group of Danish citizens. The questionnaires were returned by 1,761 (82%) of 2,146 recipients; 1,609 (75%) agreed to participate and completed the questionnaire. Only 2.8% objected to disclosing the identity of children, 9.1% objected to disclosing the identity of parents, and 6.7% objected to disclosing the identity of siblings. When genetic tests are offered to a sister, 75.4% of screened individuals with severe A1AD (phenotype "piZ") and 66.8% of piZ probands thought that the physician should say who is ill. Important reasons for informing a sister at risk were, for 58%, the opportunity to prevent disease and, for 41% of piZ-probands, the opportunity to maintain openness in the family and to avoid uncertainty. Stepwise logistic regression of background variables showed that relatives were those for whom most respondents approved the disclosure of the parents' and siblings' identities to enable the physician to examine them for the presence of A1AD. Women were less prone to disclose the identity of siblings. The results indicate that the genetic counselor should inquire about relatives' identities, to ensure that they are properly informed about the known risk of severe genetic disorder, such as A1AD, for which disability can be prevented by a change of lifestyle or by careful management. Disease prevention is essential, but openness and avoidance of uncertainty in affected families are also important. Our findings imply that fully informing all relatives about the disorder and about who is actually ill should be the principal rule.     

Detection of insulin-regulated GLUT4-translocation by the insertion of a protein C epitope in L6 myoblasts

Insulin stimulates glucose transport by translocation of the membrane glucose transporter GLUT4 from intracellular vesicles to the plasma membrane. GLUT4 is highly expressed in adipose tissue and skeletal muscle. We have constructed a cDNA containing the human GLUT4 inserted by a 12 amino acid protein C epitope in the first extracellular (exofacial) domain of the human GLUT4 (GLUT4-PC). Stable expression of GLUT4-PC in L6 myoblasts (L6-GLUT4-PC) was confirmed in immunofluorescence using monoclonal antibodies against protein C. The protein C staining yielded labeling in perinuclear vesicles strongly co-localizing with GLUT4 detected with antibodies directed against the endofacial part of GLUT4. The L6-GLUT4-PC cells were further characterized in a direct cell-based enzyme-linked immunosorbent assay by the use of beta-galactosidase. Cell surface binding of monoclonal protein C antibodies was detected with beta-galactosidase-conjugated secondary antibodies and chlorophenolred-beta-D-galactopyranoside (CPRG) as substrate in 2% paraformaldehyde fixed cells. In this assay, stimulation with insulin created a rapidly detectable recruitment of GLUT4-PC to the cell surface. This cell-based enzyme-linked immunosorbent GLUT4 assay was shown to be comparable with that of previously reported radioactive assays.