Shaping Rollable Display Devices: Effects of Gripping Condition, Device Thickness, and Hand Length on Bimanual Perceived Grip Comfort.

OBJECTIVE: To examine the effects of the gripping condition, device thickness, and hand length on bimanual perceived grip comfort associated with unrolling hand-held rollable screens. BACKGROUND: Rollable displays can be rolled and unrolled to change screen size. Although diverse rollable display device concepts have been suggested, little is known regarding ergonomic forms for comfortable screen unrolling. METHOD: Thirty young individuals (10 in each hand-length group) evaluated three rollable display device prototypes in three gripping conditions (no restriction on using side bezels, minimal use of side bezels, and restriction on the gripping type). Prototypes differed in their right-side thickness (2, 6, and 10 mm). Side bezel regions grasped during screen unrolling and corresponding bimanual grip comfort ratings were obtained. RESULTS: To improve perceived grip comfort and accommodate user-preferred gripping methods, rollable display devices should be 6 mm (preferably 10 mm) thick (vs. 2 mm) and have at least 20-mm-wide side bezels. Relative to device thickness, gripping conditions were more influential on grip comfort ratings. The "no restriction" condition improved grip comfort ratings and strengthened bimanual coupling in terms of grip comfort ratings. CONCLUSION: Contrary to current smartphone trends toward thinner and bezel-less designs, hand-held rollable display devices should be sufficiently thick and have sufficiently wide side bezels for screen unrolling. APPLICATION: Hand-held rollable display devices should be 6- or preferably 10-mm thick (vs. 2 mm) and have at least 20-mm-wide side bezels to ensure higher perceived grip comfort during bilateral screen unrolling.

Effects of display curvature and task duration on proofreading performance, visual discomfort, visual fatigue, mental workload, and user satisfaction.

This study examined the effects of display curvature and task duration on proofreading performance, visual discomfort, visual fatigue, mental workload, and user satisfaction. Five 27″ rear-screen mock-ups with distinct curvature radii (600R, 1140R, 2000R, 4000R, and flat) were used. Ten individuals per display curvature completed a series of four 15 min comparison-proofreading trials at a 600 mm viewing distance. Only proofreading speed benefited from display curvature, with 600R providing the highest mean proofreading speed. Proofreading speed increased and accuracy decreased for all display curvatures over the 1 h proofreading period. Visual discomfort, visual fatigue, and mental workload increased during the first 15 min of proofreading. A decrease in critical fusion frequency during that period indicated increases in visual fatigue and mental workload. A short break between 15 min proofreading tasks could be considered to prevent further degradation of task performance and ocular health.

Where to put the creases? Interactions between hand length, task, screen size, and folding method on the suitability of hand-held foldable display devices.

Limited information is available regarding ergonomic foldable display device forms. This two-stage study involving young South Koreans (divided into three hand-length groups) was conducted to determine ergonomic forms for hand-held foldable display devices considering folding/unfolding comfort and preference. Stage I obtained the suitability of three screen sizes for five tasks. Stage II evaluated 14 different bi- and tri-folding methods considering screen size, folding direction, and folding time. The effects of hand length were all non-significant. Screen size preferences were task-dependent; small screens were preferred for making calls, and medium screens for web searching and gaming. Folding methods affected folding/unfolding comfort and preference; outward screen and Z-shape screen folding were the most preferred bi- and tri-fold concepts, respectively. Screen protection and access appeared to be competing factors in the user preference determination process. Foldable screen size and folding method should be determined by considering tasks, folding/unfolding comfort, and user preferences. Practitioner summary: A 13.5 cm screen was preferred for making calls, whereas a 17.5 cm screen was best for web searching and gaming. An outward bi-fold screen concept with a 17.5 cm screen and Z-shape tri-fold screen concept with a 22.9 cm screen were preferred. Overall, the Z-shape concept was most preferred. Abbreviations: SD: standard deviation; ANOVA: analysis of variance; H: Height; W: Width; T: Thickness.

Determining Ergonomic Smartphone Forms With High Grip Comfort and Attractive Design.

OBJECTIVE: The authors aimed to identify ergonomic smartphone forms by investigating the effects of hand length, four major smartphone dimensions (height, width, thickness, and edge roundness), and smartphone mass on grip comfort and design attractiveness. BACKGROUND: Despite their potential effect on grip comfort and design attractiveness, the dimensions specified above have never been simultaneously considered in a study investigating smartphone gripping. METHOD: Seventy-two young individuals participated in a three-stage study. Stage 1 determined the ranges of the four smartphone dimensions suitable for grip comfort and identified the strengths of their influences. Stage 2 investigated the effects of width and thickness (determined to have the greatest influence) on grip comfort and design attractiveness. Mock-ups of varying masses were fabricated using the dimensions determined during the first two stages to investigate the effect of mass on grip comfort and design attractiveness in Stage 3. RESULTS: Phone width was found to significantly influence grip comfort and design attractiveness, and the dimensions of 140 × 65 (or 70) × 8 × 2.5 mm (height × width × thickness × edge roundness) provided high grip comfort and design attractiveness. The selected dimensions were fit with a mass of 122 g, with masses in the range of 106-137 g being comparable. CONCLUSION: The findings of this study contribute to ergonomic smartphone design developments by specifying dimensions and mass that provide high grip comfort and design attractiveness. APPLICATION: The dimensions and mass determined in this study should be considered for improving smartphone design grip comfort and attractiveness.

The ethanol extract of Aquilariae Lignum ameliorates hippocampal oxidative stress in a repeated restraint stress mouse model.

BACKGROUND: Chronic stress contributes to the development of brain disorders, such as neurodegenerative and psychiatric diseases. Oxidative damage is well known as a causative factor for pathogenic process in brain tissues. The aim of this study is to evaluate the neuroprotective effect of a 30% ethanol extract of Aquilariae Lignum (ALE) in repeated stress-induced hippocampal oxidative injury. METHODS: Fifty BALB/c male mice (12 weeks old) were randomly divided into five groups (n = 10). For 11 consecutive days, each group was orally administered with distilled water, ALE (20 or 80 mg/kg) or N-acetylcysteine (NAC; 100 mg/kg), and then all mice (except unstressed group) were subjected to restraint stress for 6 h. On the final day, brain tissues and sera were isolated, and stress hormones and hippocampal oxidative alterations were examined. We also treated lipopolysaccharide (LPS, 1 µg/mL)-stimulated BV2 microglial cells with ALE (1 and 5 µg/mL) or NAC (10 µM) to investigate the pharmacological mechanism. RESULTS: Restraint stress considerably increased the serum levels of corticosterone and adrenaline and the hippocampal levels of reactive oxygen species (ROS), nitric oxide (NO), and malondialdehyde (MDA). ALE administration significantly attenuated the above abnormalities. ALE also significantly normalized the stress-induced activation of astrocytes and microglial cells in the hippocampus as well as the elevation of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1ß). The in vitro assay outcome supplemented ALE could dramatically block NF-κB activation in microglia. The anti-oxidative stress effects of ALE were supported by the results of antioxidant components, 4-hydroxynonenal (4-HNE), NADPH oxidase 2 (NOX2), inducible nitric oxide synthase (iNOS) and NFE2L2 (Nrf2) in the hippocampal tissues. CONCLUSIONS: We firstly demonstrated the neuroprotective potentials of A. Lignum against hippocampal oxidative injury in repeated restraint stress. The corresponding mechanisms might involve modulations in the release of ROS, pro-inflammatory cytokines and stress hormones.

Effects of display curvature, display zone, and task duration on legibility and visual fatigue during visual search task.

This study examined the effects of display curvature (400, 600, 1200 mm, and flat), display zone (5 zones), and task duration (15 and 30 min) on legibility and visual fatigue. Each participant completed two 15-min visual search task sets at each curvature setting. The 600-mm and 1200-mm settings yielded better results than the flat setting in terms of legibility and perceived visual fatigue. Relative to the corresponding centre zone, the outermost zones of the 1200-mm and flat settings showed a decrease of 8%-37% in legibility, whereas those of the flat setting showed an increase of 26%-45% in perceived visual fatigue. Across curvatures, legibility decreased by 2%-8%, whereas perceived visual fatigue increased by 22% during the second task set. The two task sets induced an increase of 102% in the eye complaint score and a decrease of 0.3 Hz in the critical fusion frequency, both of which indicated an increase in visual fatigue. In summary, a curvature of around 600 mm, central display zones, and frequent breaks are recommended to improve legibility and reduce visual fatigue.

Antifungal Activity of Bee Venom and Sweet Bee Venom against Clinically Isolated Candida albicans.

OBJECTIVES: The purpose of this study was to investigate the antifungal effect of bee venom (BV) and sweet bee venom (SBV) against Candida albicans (C. albicans) clinical isolates. METHODS: In this study, BV and SBV were examined for antifungal activities against the Korean Collection for Type Cultures (KCTC) strain and 10 clinical isolates of C. albicans. The disk diffusion method was used to measure the antifungal activity and minimum inhibitory concentration (MIC) assays were performed by using a broth microdilution method. Also, a killing curve assay was conducted to investigate the kinetics of the anti- fungal action. RESULTS: BV and SBV showed antifungal activity against 10 clinical isolates of C. albicans that were cultured from blood and the vagina by using disk diffusion method. The MIC values obtained for clinical isolates by using the broth microdilution method varied from 62.5 µg/ mL to 125 µg/mL for BV and from 15.63 µg/mL to 62.5 µg/mL for SBV. In the killing-curve assay, SBV behaved as amphotericin B, which was used as positive control, did. The antifungal efficacy of SBV was much higher than that of BV. CONCLUSION: BV and SBV showed antifungal activity against C. albicans clinical strains that were isolated from blood and the vagina. Especially, SBV might be a candidate for a new antifungal agent against C. albicans clinical isolates.

Regulation of STEP61 and tyrosine-phosphorylation of NMDA and AMPA receptors during homeostatic synaptic plasticity.

BACKGROUND: Sustained changes in network activity cause homeostatic synaptic plasticity in part by altering the postsynaptic accumulation of N-methyl-D-aspartate receptors (NMDAR) and α-amino-3-hydroxyle-5-methyl-4-isoxazolepropionic acid receptors (AMPAR), which are primary mediators of excitatory synaptic transmission. A key trafficking modulator of NMDAR and AMPAR is STriatal-Enriched protein tyrosine Phosphatase (STEP61) that opposes synaptic strengthening through dephosphorylation of NMDAR subunit GluN2B and AMPAR subunit GluA2. However, the role of STEP61 in homeostatic synaptic plasticity is unknown. FINDINGS: We demonstrate here that prolonged activity blockade leads to synaptic scaling, and a concurrent decrease in STEP61 level and activity in rat dissociated hippocampal cultured neurons. Consistent with STEP61 reduction, prolonged activity blockade enhances the tyrosine phosphorylation of GluN2B and GluA2 whereas increasing STEP61 activity blocks this regulation and synaptic scaling. Conversely, prolonged activity enhancement increases STEP61 level and activity, and reduces the tyrosine phosphorylation and level of GluN2B as well as GluA2 expression in a STEP61-dependent manner. CONCLUSIONS: Given that STEP61-mediated dephosphorylation of GluN2B and GluA2 leads to their internalization, our results collectively suggest that activity-dependent regulation of STEP61 and its substrates GluN2B and GluA2 may contribute to homeostatic stabilization of excitatory synapses.

Large-Scale Refolding and Enzyme Reaction of Human Preproinsulin for Production of Human Insulin.

Human insulin is composed of 21 amino acids of an A-chain and 30 amino acids of a B-chain. This is the protein hormone that has the role of blood sugar control. When the recombinant human proinsulin is expressed in Escherichia coli, a serious problem is the formation of an inclusion body. Therefore, the inclusion body must be denatured and refolded under chaotropic agents and suitable reductants. In this study, H27R-proinsulin was refolded from the denatured form with ß-mercaptoethanol and urea. The refolding reaction was completed after 15 h at 15°C, whereas the reaction at 25°C was faster than that at 15°C. The refolding yield at 15°C was 17% higher than that at 25°C. The refolding reaction could be carried out at a high protein concentration (2 g/l) using direct refolding without sulfonation. The most economical and optimal refolding condition for human preproinsulin was 1.5 g/l protein, 10 mM glycine buffer containing 0.6 M urea, pH 10.6, and 0.3 mM ß-mercaptoethanol at 15°C for 16 h. The maximum refolding yield was 74.8% at 15°C with 1.5 g/l protein. Moreover, the refolded preproinsulin could be converted into normal mature insulin with two enzymes. The average amount of human insulin was 138.2 g from 200 L of fermentation broth after enzyme reaction with H27R-proinsulin. The direct refolding process for H27R-proinsulin was successfully set up without sulfonation. The step yields for refolding and enzyme reaction were comparatively high. Therefore, our refolding process for production of recombinant insulin may be beneficial to the large-scale production of other biologically active proteins.

N-methyl-D-aspartate receptors mediate activity-dependent down-regulation of potassium channel genes during the expression of homeostatic intrinsic plasticity.

BACKGROUND: Homeostatic intrinsic plasticity encompasses the mechanisms by which neurons stabilize their excitability in response to prolonged and destabilizing changes in global activity. However, the milieu of molecular players responsible for these regulatory mechanisms is largely unknown. RESULTS: Using whole-cell patch clamp recording and unbiased gene expression profiling in rat dissociated hippocampal neurons cultured at high density, we demonstrate here that chronic activity blockade induced by the sodium channel blocker tetrodotoxin leads to a homeostatic increase in action potential firing and down-regulation of potassium channel genes. In addition, chronic activity blockade reduces total potassium current, as well as protein expression and current of voltage-gated Kv1 and Kv7 potassium channels, which are critical regulators of action potential firing. Importantly, inhibition of N-Methyl-D-Aspartate receptors alone mimics the effects of tetrodotoxin, including the elevation in firing frequency and reduction of potassium channel gene expression and current driven by activity blockade, whereas inhibition of L-type voltage-gated calcium channels has no effect. CONCLUSIONS: Collectively, our data suggest that homeostatic intrinsic plasticity induced by chronic activity blockade is accomplished in part by decreased calcium influx through N-Methyl-D-Aspartate receptors and subsequent transcriptional down-regulation of potassium channel genes.

Target genes involved in antiproliferative effect of modified ginseng extracts in lung cancer A549 cells.

Lung cancer is the most common cancer and the leading cause of cancer-related deaths. Panax ginseng has long been used to treat cancer and other diseases worldwide. Most of the pharmacological actions of ginseng are attributed to a variety of ginsenosides, which are often metabolized by intestinal bacteria into more effective forms. In this study, we found that the antiproliferative activity of ginseng was increased after enzymatic processing of ginseng saponin (50% inhibitory concentration, >70 µg/ml). To elucidate the mechanism by which modified ginseng extract (MGX) induced cell death in human lung cancer cells, the gene expression profiles of A549 cells regulated by MGX were assayed using Agilent PrimeView Human Gene Expression Arrays. The expression of 17 genes involved in the regulation of cell signaling, cell metabolism, transport, and cytoskeleton-regulation was up-regulated, whereas the expression of 16 genes implicated in invasion and metastasis and cellular metabolism was down-regulated in MGX-treated A549 cells. Moreover, nuclear staining with 4',6-diamidino-2-phenylindole revealed that MGX clearly caused nuclear condensation and fragmentation which are observed in apoptosis cell. These results elucidate crucial anticancer mechanisms of MGX and provide potential new targets for the assessment of anticancer activity of MGX.

Expression and purification of recombinant human granulocyte colony-stimulating factor in fed-batch culture of Escherichia coli.

Granulocyte colony-stimulating factor (G-CSF) is a cytokine that has multiple roles in hematopoietic cells such as the regulation of proliferation and differentiation. Here, we describe fed-batch culture, refolding, and purification of rhG-CSF. The suitability of urea or sarcosine for solubilizing inclusion bodies (IBs) was tested. It was observed that urea is more efficient for solubilizing and refolding IBs than sarcosine is. The purity of rhG-CSF and the removal percentage of the rhG-CSF isoforms during purification were increased by pH 5.5 precipitation. The purity and the yield of purified rhG-CSF were 99% and 0.5 g of protein per liter culture broth, respectively. Our protocols of recombinant protein purification using ion exchange chromatography and semipreparative high performance liquid chromatography of pH-precipitated refolded solution may be informative to the industrial scale production of biopharmaceuticals.

Isolation and Characterization of a 32-kDa Fibrinolytic Enzyme (FE-32kDa) from Gloydius blomhoffii siniticus Venom: Fibrinolytic Enzyme from Gloydius blomhoffii siniticus Venom.

OBJECTIVES: This study was undertaken to isolate a fibrinolytic enzyme from the snake venom of Gloydius blomhoffii siniticus and to investigate its enzymatic characteristics and hemorrhagic activity as a potential pharmacopuncture agent. METHODS: The fibrinolytic enzyme was isolated by using chromatography, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and fibrin plate assay. The characteristics of the enzyme were investigated using fibrin plate assay, protein hydrolysis analysis, and hemorrhage assay. Its amino acid composition was determined. RESULTS: The fibrinolytic enzyme with the molecular weight of 32kDa (FE-32kDa) from Gloydius blomhoffii siniticus showed a fibrin hydrolysis zone at the concentration of 0.2 mg/mL in the fibrin plate assay. The fibrin hydrolysis activity of the enzyme was inhibited completely by ethylenediaminetetraacetic acid (EDTA), ethyleneglycoltetraacetic acid (EGTA), and 1, 10-phenanthroline, thiothreitol and cysteine, and partially by phenylmethanesulfonylfluoride (PMSF). Metal ions such as Fe(2+) and Hg(2+) inhibited the fibrin hydrolysis completely, but Zn(2+) enhanced it. FE-32kDa hydrolyzed α-chain but did not hydrolyze ß-chain and γ-chain of fibrinogen. High-molecular-weight polypeptides of gelatin were hydrolyzed partially into low-molecular-weight polypeptides, but the extent of hydrolysis was limited. FE-32kDa induced hemorrhage beneath back skin of mice at the dose of 2 µg. CONCLUSIONS: FE-32kDa is a α-fibrin(ogen)olytic metalloprotease that requires Zn(2+) for fibrinolytic activity and causes hemorrhage, suggesting that the enzyme is not appropriate for use as a clinical pharmacopuncture.

Study on a 4-week recovery test of sweet bee venom after a 13-week, repeated, intramuscular dose toxicity test in sprague-dawley rats.

OBJECTIVES: This study was performed to check for reversibility in the changes induced by a 13-week, repeated, dose toxicity test of Sweet Bee Venom (SBV) in Sprague-Dawley (SD) rats. METHODS: Fifteen male and 15 female SD rats were treated with 0.28 mg/kg of SBV (high-dosage group) and the same numbers of male and female SD rats were treated with 0.2 mL/kg of normal saline (control group) for 13 weeks. We selected five male and five female SD rats from the high-dosage group and the same numbers of male and female SD rats from the control group, and we observed these rats for four weeks. We conducted body-weight measurements, ophthalmic examinations, urinalyses and hematology, biochemistry, histology tests. RESULTS: (1) Hyperemia and movement disorder were observed in the 13-week, repeated, dose toxicity test, but these symptoms were not observed during the recovery period. (2) The rats in the high-dose group showed no significant changes in weight compared to the control group. (3) No significant differences in the ophthalmic parameters, urine analyses, complete blood cell counts (CBCs), and biochemistry were observed among the recovery groups. (4) No changes in organ weights were observed during the recovery period. (5) Histological examination of the thigh muscle indicated cell infiltration, inflammation, degeneration, necrosis of muscle fiber, and fibrosis during the treatment period, but these changes were not observed during the recovery period. The fatty liver change that was observed during the toxicity test was not observed during the recovery period. No other organ abnormalities were observed. CONCLUSION: The changes that occurred during the 13-week, repeated, dose toxicity test are reversible, and SBV can be safely used as a treatment modality.

Simplified large-scale refolding, purification, and characterization of recombinant human granulocyte-colony stimulating factor in Escherichia coli.

Granulocyte-colony stimulating factor (G-CSF) is a pleiotropic cytokine that stimulates the development of committed hematopoietic progenitor cells and enhances the functional activity of mature cells. Here, we report a simplified method for fed-batch culture as well as the purification of recombinant human (rh) G-CSF. The new system for rhG-CSF purification was performed using not only temperature shift strategy without isopropyl-l-thio-ß-d-galactoside (IPTG) induction but also the purification method by a single step of prep-HPLC after the pH precipitation of the refolded samples. Through these processes, the final cell density and overall yield of homogenous rhG-CSF were obtained 42.8 g as dry cell weights, 1.75 g as purified active proteins, from 1 L culture broth, respectively. The purity of rhG-CSF was finally 99% since the isoforms of rhG-CSF could be separated through the prep-HPLC step. The result of biological activity indicated that purified rhG-CSF has a similar profile to the World Health Organization (WHO) 2(nd) International Standard for G-CSF. Taken together, our results demonstrate that the simple purification through a single step of prep-HPLC may be valuable for the industrial-scale production of biologically active proteins.

Isolation from Gloydius blomhoffii siniticus Venom of a Fibrin(ogen)olytic Enzyme Consisting of Two Heterogenous Polypeptides.

OBJECTIVE: This study was undertaken to isolate a fibrin(ogen)olytic enzyme from the snake venom of Gloydius blomhoffii siniticus and to investigate the enzymatic characteristics and hemorrhagic activity of the isolated enzyme as a potential pharmacopuncture agent. METHODS: The fibrinolytic enzyme was isolated by using chromatography, sodium dodecyl sulfatepolyacrylamide gel electrophoresis, and fibrin plate assay. The characteristics of the enzyme were determined by using fibrin plate assay, protein hydrolysis analysis, and hemorrhage assay. Its amino acid composition was determined. RESULTS: The fibrin(ogen)olytic enzyme with the molecular weight of 27 kDa (FE-27kDa) isolated from G. b. siniticus venom consisted of two heterogenous disulfide bond-linked polypeptides with the molecular weights of 15 kDa and 18 kDa. When more than 20 µg of FE-27kDa was applied on the fibrin plate, fibrinolysis zone was formed as indicating its fibrinolytic activity. The fibrinolytic activity was inhibited completely by phenylmethanesulfonylfluoride (PMSF) and ethylenediaminetetraacetic acid (EDTA) and partially by thiothreitol and cysteine. Metal ions such as Hg(2+) and Fe(2+) inhibited the fibrinolytic activity completely, but Mn(2+) did not. FE-27kDa preferentially hydrolyzed α- chain of fibrinogen and slowly hydrolyzed ß- chain, but did not hydrolyze γ- chain. High-molecular-weight polypeptides of gelatin were hydrolyzed partially into polypeptides with molecular weights of more than 45 kDa. A dosage of more than 10 µg of FE- 27kDa per mouse was required to induce hemorrhage beneath the skin. CONCLUSION: FE-27kDa was a serine proteinase consisting of two heterogeneous polypeptides, hydrolyzed fibrin, fibrinogen, and gelatin, and caused hemorrhage beneath the skin of mouse. This study suggests that the potential of FE-27kDa as pharmacopuncture agent should be limited due to low fibrinolytic activity and a possible side effect of hemorrhage.

Nature and fate of supranormal differential renal function: lessons from long-term follow-up after pyeloplasty.

OBJECTIVE: To understand the nature and long-term fate of supranormal differential renal function (snDRF), analysis of a post-pyeloplasty database was performed. MATERIALS AND METHODS: Preoperative diethylenetriaminepentaacetic acid (DTPA) diuretic renal scans (DRS) identified 33 children with snDRF (>55%). Postoperatively, all showed improved hydronephrosis in ultrasound imaging or normalized drainage pattern in DRS during more than 5 years of follow-up. The fate of snDRF was described, and the nature of snDRF was speculated by associating it with clinical and ultrasound-related variables. RESULTS: Median age at operation was 22 months. Preoperative hydronephrosis was grade III in 27 patients (82%) and grade IV in 6 (18%). Hydronephrosis was normalized or improved, showing relief of obstruction. Overall fate of snDRF revealed significant reduction of DRF in 23 patients (70%), of whom 18 (81%) showed normalization during 5 years of follow-up. Stationary change of snDRF was seen in one-third of patients. Comparison of clinical and ultrasound-related variables revealed lower age, lower renal parenchyma thickness (RPT) increase, and higher preoperative DRF in the normalized group compared with the other group. The normalized group also showed a higher number in Society of Fetal Urology grade 4 hydronephrosis and lower RPT, although they reached borderline statistical significance. CONCLUSION: Long-term follow-up revealed that 70% of snDRF significantly decreased and normalized in most patients. The normalized group was younger and showed more hydronephrotic changes. Hydronephrotic change is suggested as a possible cause of snDRF.

A stem-group cnidarian described from the mid-Cambrian of China and its significance for cnidarian evolution.

Palaeontological data of extinct groups often sheds light on the evolutionary sequences leading to extant groups, but has failed to resolve the basal metazoan phylogeny including the origin of the Cnidaria. Here we report the occurrence of a stem-group cnidarian, Cambroctoconus orientalis gen. et sp. nov., from the mid-Cambrian of China, which is a colonial organism with calcareous octagonal conical cup-shaped skeletons. It bears cnidarian features including longitudinal septa arranged in octoradial symmetry and colonial occurrence, but lacks a jelly-like mesenchyme. Such morphological characteristics suggest that the colonial occurrence with polyps of octoradial symmetry is the plesiomorphic condition of the Cnidaria and appeared earlier than the jelly-like mesenchyme during the course of evolution.

Binding strength-associated toxicity reduction by birnessite and hydroxyapatite in Pb and Cd contaminated sediments.

In situ stabilization of sediment-bound heavy metals has been proposed as an alternative to ex situ treatment due to the concerns on ecosystem disturbance and remediation cost. The present study was conducted to test the performance of birnessite, hydroxyapatite, and zeolite as stabilizing agents for Pb and Cd in sediment. The heavy metal binding capacity and strength of the stabilizing agents were determined by analyzing Langmuir model parameters. The three agents showed the similar binding capacity (i.e., maximum monolayer sorption constant, K(a)) ranging from 1.13 to 3.62×10(5) mg/kg for Pb and 1.07 to 1.33×10(5) mg/kg for Cd. In contrast, binding strength (i.e., binding energy constant, b) of birnessite and hydroxyapatite was about one order higher than that of zeolite. This is further supported by five-step sequential extraction data: more than 99 and 70% of freshly spiked Pb and Cd were present as not-readily extractable fractions in birnessite and hydroxyapatite, respectively while the fractions were 17.9 and 14.1% in zeolite. Toxicity Characteristic Leaching Procedure (TCLP) test was also conducted to verify the effectiveness of the heavy metal-stabilizing ability of birnessite and hydroxyapatite. Birnessite successfully retained both Pb and Cd against the leaching solution, satisfying the TCLP extract concentration limits (i.e., 5 and 1 mg/L, respectively). However, hydroxyapatite released about 223.7 mg/L of Cd into the solution, which greatly exceeded the limit. The toxicity test with Hyalella azteca showed that their survival rate increased by 92.5-100% when birnessite or hydroxyapatite was added to Pb- or Cd-spiked sediment as a stabilizing agent. Our data demonstrate the potential use of birnessite and hydroxyapatite as an effective in situ remediation means for heavy metal-contaminated sediment with minimal risk to the aquatic ecosystem.

Stereo channels with different temporal frequency tunings.

To investigate the spatial and temporal frequency tunings for stereopsis, we measured the contrast sensitivity for depth discrimination with variable spatiotemporal frequencies and disparities using drifting sinusoidal gratings. The results showed that the contrast sensitivity changed with the stimulus disparity and the disparity tuning function varied with the spatial frequency. The disparity in the peak sensitivity decreased proportionally with the spatial frequency (size-disparity correlation). Although the temporal frequency exhibited a limited influence on the peak disparity, the temporal frequency tuning varied with the spatial frequency. The shape of the temporal frequency tuning function was lowpass for higher spatial frequencies, whereas it was bandpass for low spatial frequencies. These results suggest that more than one channel with different temporal as well as spatial frequency tunings contribute to stereopsis.