Impact of Urbanization and Climate Change on Aquifer Thermal Regimes

We evaluated the past impacts of urbanization and climate change on groundwater—in particular, aquifer temperature—in the Sendai plain, Japan, and further compared with the probable changes due to changing climate in the future. A series of simulations were performed and matched with the observed temperature-depth profiles as a preliminary step for parameter calibration. The magnitude of ground surface warming estimated from subsurface temperature spans 0.9–1.3°C, which is consistent with the calibrated ground surface warming rates surrounding various observation wells (0.021–0.015°C/year) during the last 60 years. We estimate that approximately 75% of the ground surface temperature change can be attributed to the effect of past urbanization. For the climate predictions, climate variables produced by the UK Hadley Centre’s Climate Model (HadCM3) under the A2, A1B and B1 scenarios were spatially downscaled by the transfer function method. Downscaled monthly data were used in a water budget analysis to account for the variation in recharge and were further applied in a heat transport equation together with the estimated ground surface warming rates in 2080. Anticipated groundwater recharge under the projected climate in 2080 would decrease by 1–26% compared to the 2007 estimates, despite the projected 7–28% increase in precipitation, due to a higher degree of evapotranspiration resulting from a 2.5–3.9°C increase in surface air temperature. The overall results from the three scenarios predict a 1.8–3.7°C subsurface temperature change by 2080, which is notably greater than the previous effect of urbanization and climate change on aquifer temperature in the Sendai plain.     

Protein kinase A increases the tension cost and unloaded shortening velocity in skinned rat cardiac muscle

To address controversies concerning the effect of beta-adrenergic stimulation on the rate of cross-bridge cycling in cardiac muscle, we measured ca(2+)-induced isometric tension development, unloaded shortening velocity (Vmax) and ATPase activity of demembranated (Triton X-100 skinned) rat right ventricular trabeculae before and after treatment with the catalytic subunit of protein kinase A (PKA), which is known to mimic the action of beta-adrenergic agonists in demembranated preparations. PKA treatment (1 U/microliter, 40 min) shifted the pCa-tension relation to the right from 5.41 to 5.26 at pCa50 (the [Ca2+] required for half maximal steady state tension) without changing the steepness of the pCa-tension relation and the maximum Ca(2+)-activated tension; Vmax, as determined by the slack test, was increased for a given pCa value, despite the reduced level of isometric tension. PKA treatment also shifted the pCa-ATPase activity to the right slightly from 5.47 to 5.40 at pCa50 (the [Ca2+] required for half maximal ATPase activity), but increased the ATPase activity during a given level of steady isometric tension generation, resulting in a 33% increase of the tension cost (ATPase activity/tension). All the results obtained strongly suggest that, in rat right ventricular trabeculae, beta-adrenergic stimulation may increase the rate of cross-bridge cycling by increasing the rate of cross-bridge detachment from actin through a PKA-mediated mechanism, although PKA reduces the Ca(2+)-sensitivity of the contractile system.     

Cold-adapted structural properties of trypsins from walleye pollock (<Emphasis Type="Italic">Theragra chalcogramma</Emphasis>) and Arctic cod (<Emphasis Type="Italic">Boreogadus saida</Emphasis>)

Complementary DNA clones encoding trypsins were isolated from pyloric ceca of cold-adapted fish, walleye pollock (Theragra chalcogramma) (WP-T) and Arctic cod (Boreogadus saida) (AC-T). The isolated full-length cDNA clones of WP-T and AC-T were 852 and 860 bp, respectively, and both cDNAs were contained an open reading frame of 726 bp. WP-T and AC-T seemed to be synthesized as preproenzyme that contains a signal peptide, an activation peptide, and a mature trypsin. Although the amino acid sequence identities of WP-T and AC-T to that of bovine trypsin were 64 and 63%, respectively, they completely conserved the structural features for catalytic function of trypsin. On the other hand, WP-T and AC-T possessed the four Met residues (Met135, Met145, Met175 and Met242) in their molecules and the deletion of Tyr151 and substitution of Pro152 for Gly in their autolysis loops when aligned with the sequences of tropical-zone fish and bovine trypsins. In addition, the contents of charged amino acid residues at the N-terminal regions (positions 20–50) of WP-T and AC-T were extremely higher than those of other fish and bovine trypsins. Moreover, one amino acid (Asn72) and two amino acids (Asn72 and Val75) coordinating with Ca²⁺ in bovine trypsin were exchanged for another amino acids in WP-T (His) and AC-T (His and Glu), respectively, and the contents of negative charged amino acids at their Ca²⁺-binding regions were lower than those of tropical-zone fish and bovine trypsins. Therefore, it was considered that these structural characteristics of WP-T and AC-T are closely related to their lower thermostability.     

Inhibitory effects of funoran on the adherence and colonization of oral bacteria

Funoran, a sulfated polysaccharide extracted from the seaweed Gloiopeltis furcata, strongly inhibited the adsorption of mutans streptococci to saliva-coated hydroxyapatite (S-HA) used as an experimental pellicle and strongly desorbed cariogenic mutans streptococci pre-adsorbed to S-HA. Colonization inhibition and anticariogenic effects of funoran were also investigated in experimental rats. The colonization of Streptococcus cricetus E49 inoculated on the molar teeth of experimental rats administered funoran was less frequent than that in a funoran-free group. The mean buccal and lingual, sulcal, and total caries scores of rat groups administered funoran were significantly lower than those of the funoran-free group. The inhibitory effect of funoran on periodontopathic bacterial attachment was studied in vitro. Funoran strongly inhibited the adsorption of Porphyromonas gingivalis, Fusobacterium nucleatum, and actinomyces species to S-HA and collagen-coated hydroxyapatite (Co-HA) and apparently inhibited their attachment to the human gingival fibroblast Gin-1 cell line. The present study indicates that funoran inhibits colonization by cariogenic and periodontopathic bacteria and excludes them from human oral cavity.     

Involvement of phosphoinositide 3-kinase in regulation of adhesive activity of highly metastatic hepatoma cells

We have established hepatoma clones from benzopyrene-treated liver cells, one of which (G-5) shows extensive metastasis to the lung when injected subcutaneously into mice [Tanigaki, Y. et al. (1995) Invasion Metastasis 15, 70-80]. In the present study, we performed in vitro assays suitable for examination of the adhesive and invasive properties of the highly metastatic cells. G-5 cells efficiently entered the pores of fibronectin-coated filters. Treatment of the cells with an inhibitor of phosphoinositide 3-kinase (PI 3-kinase), wortmannin, significantly impaired the invasive activity. A structurally unrelated inhibitor, 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002) also prevented invasion. Both inhibitors suppressed cell adhesion to fibronectin-coated dishes. G-5 cells were next transfected with a mutant regulatory subunit (Deltap85) of PI 3-kinase, which was expected to impair the function of PI 3-kinase. The transfectants showed suppressed adhesion to the dishes and did not efficiently migrate into the filters. The lower adhesive ability of the transfected cells was not further affected by inhibitors of PI 3-kinase. Thus, PI 3-kinase activity contributes significantly to the adhesive and invasive properties of G-5 cells.     

Dual stimulatory and inhibitory effects of fluorine-substitution on mutagenicity: an extension of the enamine epoxide theory for activation of the quinoline nucleus

OBJECTIVE: The incidence and distribution of enamel defects among patients with celiac disease were examined. STUDY DESIGN: The oral cavity was explored in 137 patients with celiac disease (mean age 16.2 years; age range 5 to 68 years) and in 52 control patients (mean age 19.8 years; age range 5 to 64 years). Permanent dentition enamel defects were recorded, along with their number and locations. The decayed, missing, and filled teeth index rates were also established, and an investigation was made of the human leukocyte antigens among the patients with celiac disease. The results obtained were analyzed with the chi-squared test, statistical significance being regarded for p < or = 0.05. RESULTS: Enamel defects were observed in 72 (52.5%) of the patients with celiac disease (52 patients had systematic defects) and in 22 (42.3%) of the control patients (9 patients had systematic defects). Systematic defects were significantly more common in the celiac disease group. In the patients with celiac disease, 72.2% were symmetrical, compared with 40.9% of the defects in the control patients. The incisors were the most frequently affected teeth, the extent of involvement being significantly greater in the celiac disease group. In patients with celiac disease, DR7, DR3, and DQ2 were the most commonly observed human leukocyte antigens. The mean decayed, missing, and filled teeth index rates were 4.8 and 6.2 in the celiac disease group and the control group, respectively. CONCLUSIONS: Enamel defects are common among patients with celiac disease. They tend to be bilateral and symmetrical, and they are chronologically distributed. The lesions affect mainly the incisors and the molars. Patients with such characteristics should be evaluated for possible celiac disease.     

A 30-ns 64-Mb DRAM with built-in self-test and self-repair function

A 64-Mb dynamic random access memory (DRAM) with a 30-ns access time and 19.48-mm×9.55-mm die size has been developed. For reducing inter-bit-line coupling noise, the DRAM features a latched-sense, shared-sense circuit with open bit-line readout and folded bit-line rewrite operations. To reduce test costs and increase chip reliability, it has been equipped with built-in self-test and self-repair (BIST and BISR) circuits that use spare SRAM cells     

Inside Front Cover: Mobility and Dynamics of Charge Carriers in Rubrene Single Crystals Studied by Flash‐Photolysis Microwave Conductivity and Optical Spectroscopy (Adv. Mater. 5/2008)

Electrodeless photoconductivity measurements of a rubrene single crystal are performed by microwave conductivity and transient optical spectroscopy, demonstrating anisotropy and ambipolarity. From these comprehensive studies, Akinori Saeki, Seiichi Tagawa, and co‐workers discuss on p. 920 the optoelectronic properties of rubrene single crystal in terms of charge recombination of holes and electrons, exciton–exciton annihilation, quantum efficiency of charge carrier generation, triplet contribution, and the extinction coefficients of ionic species accessed by pulse radiolysis.