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Little is known about the ecology of insect species in the hyporheic zone of rivers, despite its importance in understanding how species survive in specialized habitats. We report on the life history and trophic characteristics of the hyporheic stonefly species Alloperla ishikariana Kohno, 1953 (Order: Plecoptera, Family: Chloroperlidae) in a gravel-bed river in northern Japan, using year-round sampling of both benthic and hyporheic larvae, as well as flying adults in the riparian zone. Adults emerged between May and August, and the larval cohort structure consisted of three sized groups with some sex dimorphism in their body size, with an average growth rate of 0.0043 mg/day. Diet analyses based on C and N stable isotope ratios indicated minimal ontogenetic diet shifts. In contrast, the temporal diet shift was more apparent with higher dependence on Oligochaeta in winter, with an increasing dependence on Chironomidae in spring and early summer. Other insect taxa, namely, Leuctridae and small-sized Lepidostoma, demonstrated a high to moderate affinity for the hyporheic zone. Alloperla ishikariana spent most of its larval stage in the hyporheic zone. With adults living from 7 to 10 days, A. ishikariana completes a life span of approximately 3 years with its larval stage in the dark. [ABSTRACT FROM AUTHOR]

Classical simultaneous confidence bands for survival functions (i.e., Hall–Wellner, equal precision, and empirical likelihood bands) are derived from transformations of the asymptotic Brownian nature of the Nelson–Aalen or Kaplan–Meier estimators. Due to the properties of Brownian motion, a theoretical derivation of the highest confidence density region cannot be obtained in closed form. Instead, we provide confidence bands derived from a related optimization problem with local time processes. These bands can be applied to the one-sample problem regarding both cumulative hazard and survival functions. In addition, we present a solution to the two-sample problem for testing differences in cumulative hazard functions. The finite sample performance of the proposed method is assessed by Monte Carlo simulation studies. The proposed bands are applied to clinical trial data to assess survival times for primary biliary cirrhosis patients treated with D-penicillamine. [ABSTRACT FROM AUTHOR]

For a two-group comparative study, a stratified inference procedure is routinely used to estimate an overall group contrast to increase the precision of the simple two-sample estimator. Unfortunately, most commonly used methods including the Cochran-Mantel-Haenszel statistic for a binary outcome and the stratified Cox procedure for the event time endpoint do not serve this purpose well. In fact, these procedures may be worse than their two-sample counterparts even when the observed treatment allocations are imbalanced across strata. Various procedures beyond the conventional stratified methods have been proposed to increase the precision of estimation when the naive estimator is consistent. In this paper, we are interested in the case when the treatment allocation proportions vary markedly across strata. We study the stochastic properties of the two-sample naive estimator conditional on the ancillary statistics, the observed treatment allocation proportions and/or the stratum sizes, and present a biased-adjusted estimator. This adjusted estimator is asymptotically equivalent to the augmentation estimators proposed under the unconditional setting. Moreover, this consistent estimation procedure is also equivalent to a rather simple procedure, which estimates the mean response of each treatment group first via a stratum-size weighted average and then constructs the group contrast estimate. This simple procedure is flexible and readily applicable to any target patient population by choosing appropriate stratum weights. All the proposals are illustrated with the data from a cardiovascular clinical trial, whose treatment allocations are imbalanced. [ABSTRACT FROM AUTHOR]

Ferromagnetic layered structure has been made at sub-surface of the antiferromagnetic FeRh bulk samples by high energy He ion beam irradiation. In accordance with the Transport of Ions in Matter simulation, such ion beam can effectively deposit the elastic collision energy in several lm regions in the depth from the surface. Measurement with a superconducting quantum interference device reveals the irradiated samples to be ferromagnetic. Assuming that only the part the energy deposited can be modified to be ferromagnetic, the corresponding irradiation induced magnetization is consistent with the data that we previously reported. On the other hand, the X-ray magnetic circular dichroism (XMCD) spectra for the irradiated samples are totally unchanged as those for the unirradiated samples. Since XMCD signal in total emission yield method is considered to be surface sensitive with a typical probing depth of several nm, the surface magnetic state is maintained to be antiferromagnetic. By utilizing these phenomena, three-dimensional magnetic patterning of FeRh can be realized, which may potentially be used for future magnetic exchange device application such as nano-scale sensors and memories. [ABSTRACT FROM AUTHOR]

A method for fabricating adhesively bonded joints with graded properties along the bond-line was proposed. By utilizing two types of acrylic adhesives, one hard and the other soft, the properties of the mixture were changed by controlling the mixing ratio. An applicator for the adhesives was developed and used for the experiments, in which property-graded adhesive layers were actually produced. The properties, i.e., stress-strain curves at various points of the property-graded adhesive layer, were experimentally measured, and the validity of the proposed method was confirmed. The Young's moduli at multiple points of the adhesive layer changed from 34.7 MPa to 634 MPa by changing the mixing ratio of the adhesives. [ABSTRACT FROM AUTHOR]

Physiological constraints can limit thermal niche breadth in organisms, particularly for small-bodied ectotherms. Daily temperature fluctuations often surpass annual (seasonal) temperature variation in the tropics, suggesting diel temperature cycles could drive thermal specialization by individuals that are active at different times of the day. We used foraging workers of the Neotropical ant Ectatomma ruidum to assess whether diurnally and nocturnally active workers differed in thermal tolerance. We compared critical thermal maxima (CT) of nocturnal and diurnal foraging workers to explore thermal niche specialization over the diel cycle. We predicted that diurnally active workers would have higher CT because they occupy a warmer thermal niche. As predicted, diurnal foragers exhibited significantly higher CT (mean 1.1 °C difference) than nocturnal foragers. Diurnal and nocturnal foragers were similar in body size, and there was no relationship between worker size and CT. We discuss possible mechanisms for this pattern, and the implications of within- versus between-colony differences in CT. [ABSTRACT FROM AUTHOR]

We have studied the in vitro transfection of a plasmid DNA with thelacZgene to HeLa-S3 cells and hemolysis in a red blood cell (RBC) suspension under pulsed ultrasound with duty cycles?of 10, 20 and 30% using a digital sonifier at a frequency of 20 kHz and an intensity of 6.2 W/cm2 on the surface of a horn tip. Cultured HeLa-S3 cells in suspension were exposed to pulsed ultrasound for an apparent exposure timet' from 0 to 60 s. HeLa-S3 viability decreased as a single exponential function of the total exposure timet=?t' with a common time constantt=3.8 s for three duty cycles. Transfection was evaluated by counting the number of ß-galactosidase(ß-Gal)-positive cells relative to the total number of cells. Pulsed ultrasound provided an enhanced transfer of the ß-Gal plasmid to HeLa-S3 cells, 3.4-fold as compared with that in the case of the control. The optimal transfection efficiencies were 0.75, 0.80 and 0.74% neart=twith?=10, 20 and 30%, respectively. The number ratio of ß-Gal-positive cells to the surviving cells after exposure increased witht' according to a modified logistic equation. The degree of hemolysis also increased exponentially witht' at a time constantt'=t0/?for the RBC suspension in physiological saline at a hematocrit concentration of 0.5% witht0=0.9 s. Thus the total exposure time for the optimal transfection efficiency wast, that is, nearly four times oft0. Hemolysis in the RBC suspension may be a useful model for determining optimal transfection by pulsed ultrasound of various duty cycles. [ABSTRACT FROM AUTHOR]

Background: The prevalence of Helicobacter pylori infection in Crohn's disease (CD) patients was investigated to determine whether the presence and severity of gastroduodenal lesions were related to H. pylori infection.Methods: Infection rates were compared between CD group (n = 90) and the control group (n = 525). Correlations between endoscopically detected lesions and H. pylori positive rates were investigated. The relationship between drug therapy and the prevalence of H. pylori infection was also analyzed.Results: H. pylori-positive rate of the 90 CD patients attending our clinic was 16.7%, significantly lower than the rate in healthy controls (40.2%) (P = 0.0001). The involvement of H. pylori infection in the gastroduodenal lesions of CD patients was also examined. The prevalence of gastroduodenal lesions in all CD patients was high, 92.2%. The lesions observed included ulcers, erosion, and "bamboo joint-like lesions" of the stomach, and ulcers, erosion, stenosis, and elevated lesions of the duodenum. None of these lesions were found to be related to H. pylori infection. However, H. pylori infection was found to exacerbate gastric ulcers (P = 0.036). The analysis of a possible relationship between a history of drug therapy and the low prevalence of H. pylori infection in CD patients showed that the prevalence of H. pylori infection was significantly lower in patients who had received antibiotics for 2 weeks or more (P = 0.002).Conclusions: The results suggest that H. pylori infection is essentially unrelated to the gastroduodenal lesions observed in CD. It seems likely, however, that H. pylori infection may exacerbate gastric ulcers and that H. pylori can be eradicated by prolonged use of antibiotics. [ABSTRACT FROM AUTHOR]

To clarify the relation between neuronal protection against ischaemia and calcium/calmodulin-dependent protein kinase II (CaM kinase II) activity, we investigated temporal alterations of the kinase activity in the hippocampus after transient forebrain ischaemia under neuroprotective conditions, employing the gerbil bilateral carotid artery occlusion model. The hippocampal CA1 neuronal density at 2 hours after 5 minutes of forebrain ischaemia was 214.7±25.8 /mm (mean±S.D.), and did not differ from the control significantly; however, it decreased to 11.7±4.2 /mm at 7 days after the ischaemia. The neuronal density at 7 days after the ischaemia was 185.1±18.5 under the hypothermic conditions, 128.7±19.6 with the brief ischaemic pretreatment, 65.0±13.4 with administration of MK-801, and 20.5±4.2 with the repetitive hyperthermic pretreatment, respectively. The Ca2+/calmodulin-dependent activity of CaM kinase II in the hippocampal cytosolic fraction was decreased to 47.5% of the control value at 2 hours after the ischaemia, when CA1 neuronal death was not observed. In contrast, the activity was 98.8% of the control under the hypothermic conditions, 91.4% with the brief ischaemic pretreatment, 71.2% with administration of MK-801, and 47.9% with the repetitive hyperthermic pretreatment, respectively. These results indicated that the preservation of the Ca2+/calmodulin-dependent activity of cytosolic CaM kinase II after ischaemia parallelled the neuroprotective effect in the gerbil hippocampus. Thus, it is suggested that the preservation of the activity may be involved in the mechanism of neuronal protection against ischaemia. [ABSTRACT FROM AUTHOR]

The mechanism of the adhesion of the suspension particles on the wall surface of the glass container is discussed. Two types of mechanism are found; 1) simple adhesion where no mutual affinity or interaction exists between the particle and the wall, 2) adhesion with affinity. In the case of the simple adhesion, the suspension particle is pressed against the wall and trapped by a thin medium film, whose pressure increases with decreasing of the medium film thickness. Important in this process is the liquid film formation on the wall. Under the pressure, the particle superdissolves into the thin liquid film at the contacting point, and the excess particle component produced deposits on both surfaces of the wall and the particle, where no direct pressure works upon. The adhesion strength increases as time goes by, since the deposition grows according to time, as long as the medium film presents and the pressure works on the particle. Adhesion due to deposition is not so popular as that due to affinity, but it is considered as an important basic form of the adhesion. For the affinity adhesion, the commonest affinity is a hydrophobic bonding effect, which may be explained by van der Waals coefficient and by determination of sliding angle of the suspension particle in the dispersion medium. Electrostatic affinity is less popular than affinity by hydrophobic bonding, but adsorption of the medium component onto the particle or the wall sometimes causes the adhesion due to this. Zeta potential of chloramphenicol crystals and glass powder was measured and its influence on the adhesion was discussed in connection with adsorption of benzethonium chloride. It was found that the adhesion strength of this type does not increase with lapse of time. [ABSTRACT FROM AUTHOR]

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Improving the quality of ulcer healing (QOUH) is one of the valid methods of prevention of relapse of gastric ulcers. We investigated the effect of lafutidine on the QOUH of gastric ulcer compared with famotidine in a randomized, multi-centre controlled trial. Consecutive 80 patients with a gastric ulcer were randomly assigned to receive twice daily either lafutidine (10 mg) or famotidine (20 mg) for 12 weeks. Esophagogastroduodenoscopy was performed to examine the ulcer healing rate and rate of fl at type ulcer scars using dye-contrast. The gastric ulcer healing rate was 92.1% in the lafutidine group (35/38) and 94.7% in the famotidine group (36/38). The rate of flat-type ulcer scars was significantly higher in the lafutidine group (68.4%, 26/38) than in the famotidine group (42.1%, 16/38) (P = 0.021). In conclusion, the present study demonstrated that lafutidine, as compared to famotidine, yields a signifi cantly superior QOUH in patients with gastric ulcers in the clinical setting. [ABSTRACT FROM AUTHOR]

: Several studies in Western countries showed that proton-pump inhibitors are superior to histamine2-receptor antagonists or placebo in the treatment of non-erosive gastro-oesophageal reflux disease. The efficacy of acid-suppressive drugs for non-erosive gastro-oesophageal reflux disease in Japan, in which the prevalence ofHelicobacter pyloriinfection is higher compared with Western countries, is unknown.: To compare the efficacy of famotidine and omeprazole in Japanese patients with non-erosive gastro-oesophageal reflux disease by a prospective randomized multicentre trial.: A total of 98 patients received either famotidine 20 mg b.d. (n = 48) or omeprazole once daily (n = 50). Frequency of gastro-oesophageal reflux disease symptoms and health-related quality of life were evaluated at baseline and after 4 weeks of treatment. Complete relief was defined as no gastro-oesophageal reflux disease symptoms during the 7-day interval in week 4.: Complete relief was achieved in 23 (48%) of patients receiving famotidine and 28 (56%) of patients treated with omeprazole. In the famotidine group, complete relief rate inH. pylori-negative patients was significantly lower thanH. pylori-positive patients (35% vs. 64%). Both famotidine and omeprazole improved most scales of health-related quality of life. Omeprazole significantly improved reflux score irrespective ofH. pyloriinfection while famotidine significantly improved reflux score inH. pylori-positive patients but not inH. pylori-negative patients.: Omeprazole is more effective than famotidine for the control of gastro-oesophageal reflux disease symptoms inH. pylori-negative patients, while similar efficacy is observed inH. pylori-positive patients with non-erosive gastro-oesophageal reflux disease. [ABSTRACT FROM AUTHOR]

In patients with severe hypertension, chronic heart failure or a history of stroke, the lower limit of autoregulation of cerebral blood flow (CBF) is shifted to higher levels of blood pressure (BP) than those observed in healthy subjects. The aim of pharmacotherapy for hypertensive patients with an impaired autoregulation of CBF should be to reduce BP while preserving an appropriate CBF. In the present study, 16 hypertensive patients who had had an episode of stroke more than 4 weeks previously were administered the angiotensin II (AT1) receptor antagonist losartan at daily doses of 25-100?mg for 4 weeks. Systolic and diastolic blood pressures were recorded for 24?h using an ambulatory BP monitoring system. CBF in both hemispheres of the cerebrum and cerebellum was quantified using single photon emission tomography with N-isopropyl-p-[123I]iodoamphetamine. At baseline, CBF was 29.7±6.7?ml/min/100?g in the cerebrum and 31.5±7.5?ml/min/100?g in the cerebellum. At the end of treatment, BP was lower, while CBF increased by 7.7%in the cerebrum, and remained at the baseline level in the cerebellum. Thus, CBF was preserved despite the reduction in BP. We consider the use of losartan is advantageous for hypertensive patients with a history of stroke in whom autoregulation of CBF is potentially impaired.Journal of Human Hypertension (2004) 18, 693-699. doi:10.1038/sj.jhh.1001735 Published online 6 May 2004 [ABSTRACT FROM AUTHOR]