Imagining the Future of the Anthropology of Education if We Take Laura Nader Seriously

The large corpus of scholarship of cultural anthropologist Laura Nader is relevant to the contemporary practice of the anthropology of education. In particular, her work is relevant to contemporary debates about methodology and what constitutes "scientifically based" education research; to the prospect and need for more crossfertilization within the discipline of anthropology; and for the proud assertion of anthropology's distinctive suitability for understanding and responding to many contemporary educational challenges, including how to have anthropologically derived insights more favorably compete in the "marketplace of ideas" against less empirically grounded claims and strategies.     

Sequence and diversity of variable gene segments coding for rabbit T-cell receptor beta chains

The nucleotide sequences of 11 variable gene segments coding for rabbit T-cell receptor beta (Tcrb-V) chains were determined by directly sequencing fragments amplified by the cassette-ligation mediated polymerase chain reaction (CLM-PCR) and by modified anchor PCR without the cloning procedure. The nucleotide sequences in two of these 11 rabbit Tcrb-V gene segments coincided with those in two of the four rabbit Tcrb-V gene segments previously reported; the others have not been described. The percentage similarity of each nucleotide sequence of the 11 rabbit Tcrb-V gene segments was analyzed and the segments were divided into nine families, which were homologous to nine human families (Vb 2, 3, 4, 5, 7, 8, 10, 18, and 22), respectively.The nucleotide sequence data reported in this paper have been submitted to the DDBJ, EMBL, and GenBank nucleotide sequence databases and have been assigned the accession numbers D17416-D17426.     

Deleted in Liver Cancer 2 (DLC2) Was Dispensable for Development and Its Deficiency Did Not Aggravate Hepatocarcinogenesis

DLC2 (deleted in liver cancer 2), a Rho GTPase-activating protein, was previously shown to be underexpressed in human hepatocellular carcinoma and has tumor suppressor functions in cell culture models. We generated DLC2-deficient mice to investigate the tumor suppressor role of DLC2 in hepatocarcinogenesis and the function of DLC2 in vivo. In this study, we found that, unlike homologous DLC1, which is essential for embryonic development, DLC2 was dispensable for embryonic development and DLC2-deficient mice could survive to adulthood. We also did not observe a higher incidence of liver tumor formation or diethylnitrosamine (DEN)-induced hepatocarcinogenesis in DLC2-deficient mice. However, we observed that DLC2-deficient mice were smaller and had less adipose tissue than the wild type mice. These phenotypes were not due to reduction of cell size or defect in adipogenesis, as observed in the 190B RhoGAP-deficient mouse model. Together, these results suggest that deficiency in DLC2 alone does not enhance hepatocarcinogenesis.     

The role of context in risky choice

Human choice behavior was assessed in a concurrent-chain schedule, where two equal initial links (IL) each led to a distinct terminal-link (TL). One TL was associated with a fixed ratio schedule of reinforcement, while the other was associated with a bi-valued mixed ratio schedule of reinforcement, whose arithmetic mean equaled the Fixed TL schedule. The fixed component (FR50; FR25; FR5) was arranged to be equal to the alternative mixed component in each condition (FR1/99; FR1/49; FR1/9), and choice behavior was measured by proportion of responses to each IL. In addition, the IL duration varied across conditions (VI 30 s; VI 15 s; FI 1 s). Preference for the mixed option was observed with longer durations (e.g., when IL = VI 30 s and TL = FR1/99). Participants were relatively indifferent in other conditions, though the results suggested a monotonic increase in preference as either durations or programmed efforts increased. It is concluded that both choice and the conditioned reinforcement value of the mixed option is contextually based, so that the value of a stimulus correlated with an immediate reward (i.e., FR 1) is enhanced the greater the temporal context in which the FR1 is embedded.     

A new prenyltransferase from Micrococcuslysodeikticus

A new prenyltransferase which catalyzes the synthesis of geranyl pyrophosphate as the only product from dimethylallyl pyrophosphate and isopentenyl pyrophosphate has been separated from other known prenyltransferases from $\text{Micrococcus}\text{lysodeikticus}$. This enzyme fraction is also capable of synthesizing all-$\text{trans}$ geranylgeranyl pyrophosphate from farnesyl pyrophosphate and isopentenyl pyrophosphate though it lacks ability to synthesize farnesyl pyrophosphate.     

Selenium and glutathione levels, and glutathione peroxidase activities in blood components of uremic patients on hemodialysis supplemented with selenium and treated with erythropoietin

Patients with chronic renal failure (CRF) often have reduced concentrations of selenium (Se) and lowered activities of glutathione peroxidase (GSH-Px) in blood components. The kidney is a major source of plasma GSH-Px. We measured Se and glutathione levels in blood components and red cell and plasma GSH-Px activities in 58 uremic patients on regular (3 times a week) hemodialysis (HD). The dialyzed patients were divided in 4 subgroups and were supplemented for 3 months with: 1) placebo (bakers yeast), 2) erythropoietin (EPO; 3 times a week with 2,000 U after each HD session), 3) Se-rich yeast (300 μg 3 times a week after each HD), and 4) Se-rich yeast plus EPO in doses as above. The results were compared with those for 25 healthy subjects. The Se concentrations and GSH-Px activities in the blood components of dialyzed uremic patients were significantly lower compared with the control group. Treatment of the HD patients with placebo and EPO only did not change the parameters studied. The treatment with Se as well as with Se and EPO caused an increase in Se levels and red cell GSH-Px activity. Plasma GSH-Px activity, however, increased only slowly or did not change after treatment with Se and with Se plus EPO. In the group treated with Se plus EPO the element concentration in blood components was higher compared with the group supplemented with Se alone. The weak or absence of response in plasma GSH-Px activity to Se supply indicates that the impaired kidney of uremic HD patients has reduced possibilities to synthesize this enzyme.     

Radiation capture and conversion efficiencies of Miscanthus sacchariflorus,M. sinensis and their naturally occurring hybrid M. × giganteus

Miscanthus is a rhizomatous C4 grass of great interest as a biofuel crop because it has the potential to produce high yields over a wide geographical area with low agricultural inputs on marginal land less suitable for food production. At the moment, a clonal interspecific hybrid Miscanthus × giganteus is the most widely cultivated and studied in Europe and the United States, but breeding programmes are developing newer more productive varieties. Here, we quantified the physiological processes relating to whole season yield in a replicated plot trial in Wales, UK. Light capture and conversion efficiency were parameterized for four carefully selected genotypes (M. sinensis, M. sacchariflorus and Miscanthus × giganteus). Differences in the canopy architecture in mature stands as measured by the extinction coefficient (k) were small (0.55–0.65). Sensitivity analysis on a mathematical model of Miscanthus was performed to quantify the accumulative intercepted photosynthetically active radiation (iPAR) in the growing season using (i) k, (ii) variation in the thermal responses of leaf expansion rate, (iii) base temperature for degree days and (iv) date start of canopy expansion. A 10% increase in k or leaf area per degree day both had a minimal effect on iPAR (3%). Decreasing base temperature from 10 to 9 °C gave an 8% increase in iPAR. If the starting date for canopy expansion was the same as shoot emergence date, then the iPAR increases by 12.5%. In M. × giganteus, the whole season above ground and total (including below ground) radiation‐use efficiency (RUE) ranged from 45% to 37% higher than the noninterspecific hybrid genotypes. The greater yields in the interspecific hybrid M. × giganteus are explained by the higher RUE and not by differences in iPAR or partitioning effects. Studying the mechanisms underlying this complex trait could have wide benefits for both fuel and food production.     

Occurrence of an alpha-galacturonosyl-ceramide in the dioxin-degrading bacterium Sphingomonas wittichii

The chemical structure of two glycosphingolipids (GSLs) found in the dioxin-degrading bacterium Sphingomonas wittichii strain RW1 was investigated by means of mass spectrometry and (1)H-nuclear magnetic resonance spectroscopy. One of the GSLs was alpha-D-glucuronosyl-ceramide, commonly present in Sphingomonas spp., and the other was proved to be alpha-D-galacturonosyl-ceramide, whose sugar configuration has not been reported before. In both GSLs the ceramide portion was composed of myristic acid or 2-hydroxy-myristic acid as the fatty acid, and 2-amino-1,3-octadecanediol or 2-amino-cis-13,14-methylene-1,3-eicosanediol as the dihydrosphingosine.     

The use of CO2 flux time series for parameter and carbon stock estimation in carbon cycle research

Data assimilation (DA) is increasingly being employed to estimate the parameters and states of terrestrial ecosystem models from eddy covariance measurements of net carbon (C) fluxes. The length of the observation time series used varies for each study. The impact of these differences has not been quantified explicitly. Therefore, in this study, we investigate the importance of the time series length relative to observation noise and data gaps. Different length synthetic time series are used to determine the parameter and C stocks of a simple ecosystem C model. Two commonly used DA schemes are tested: the sequential Ensemble Kalman Filter (EnKF) and a batch Metropolis Markov chain Monte Carlo algorithm. Longer time series improve both the parameter and C pool estimates of the EnKF, while adversely affecting those of the Metropolis algorithm. For both DA approaches, the length of the time series has more influence on the parameter and pool estimates than the level of random noise or amount of data. In this study, the EnKF provides more robust parameter and C pool estimates than the Metropolis algorithm. Optimized parameters and states are often used as the basis for forecasting future responses. Despite having better parameter and C pool estimates, EnKF forecasts estimates have much larger uncertainties than the Metropolis algorithm forecast estimates. Finally, we suggest that the structure of simple box models, as used in this study, introduces a large degree of equifinality into DA. Neither DA scheme correctly accounts for the equifinality, but our results suggest that it is particularly problematic for the batch Metropolis algorithm.