The possibility that resource limits constrain the growth of mobile epifaunal populations associated with Sargassum patens plants was investigated by placing plants and associated animals into field ...microcosms which excluded fish predators, and then comparing faunal abundance and size-structure changes in different microcosm treatments with field populations. Four different microcosm treatments were set up: two treatments containing defaunated plants inoculated with caprellid amphipods, and two control treatments with natural faunas. The estimated secondary production of faunas enclosed in all microcosm treatments rapidly settled on a constant value (5 mg/day) which was similar to that determined in experiments conducted in Western Australia using the same microcosms but for faunas associated with a seagrass rather than a macroalga. These results support the hypothesis that the secondary production of epifaunal communities associated with macrophytes is constrained by quantifiable food resource ceilings. Predation by the most common fish species in the area, the wrasse Halichoeres tenuispinis, did not appear to alter macrofaunal production in the S. patens bed; however, it did greatly affect the faunal size-structure by eliminating most of the larger animals. The majority of epifaunal animals ≥2.0 mm sieve-size were consumed by H. tenuispinis, while negligible numbers of 0.5-mm sieve-size animals were captured. We postulate that food resource ceilings and predatory size-selectivity are widespread phenomena, affecting epifaunal populations at a variety of locations. Predation is predicted to generally increase rather than decrease faunal abundance because the consumption of each large invertebrate by a predator frees sufficient resources to feed several smaller individuals.
Recent experimental studies have revealed that traumatic brain injury as well as ischemic brain injury can cause chronic progressive neuronal damage. In the present study, we demonstrate previously ...unreported delayed cerebral atrophy on computerized tomography (CT) scans in severely head-injured patients. Seventeen severely head-injured patients who required mild hypothermia to control intracranial hypertension after the failure of conventional therapies were retrospectively analyzed. All 17 patients survived more than 1 year. Delayed neuronal loss (DNL) was observed in only eight of the 17 patients. Eight patients with DNL required longer durations of mild hypothermia to control intracranial hypertension than nine patients without DNL. Six of these eight patients with DNL achieved functional recovery despite progressive atrophic changes demonstrated on CT scans. On CT scans, DNL was characterized by (1) the sudden appearance at several months postinjury of a low-density area in the hemisphere ipsilateral to the injury; (2) the preservation of essential cortical structure although related white matter structures showed severe atrophic changes; and (3) no spread of the low-density area to the contiguous territory of the other main cerebral artery. It is concluded that focal primary injury to underlying brain, if severe enough, can result in delayed hemispheric atrophy.
Background and purpose
Corticobasal syndrome (
CBS
) is pathologically characterized by tau deposits in neuronal and glial cells and by reactive astrogliosis. In several neurodegenerative disorders,
...18
F‐
THK
5351 has been observed to bind to reactive astrocytes expressing monoamine oxidase B. In this study, the aim was to investigate the progression of disease‐related pathology in the brains of patients with
CBS
using positron emission tomography with
18
F‐
THK
5351.
Methods
Baseline and 1‐year follow‐up imaging were acquired using magnetic resonance imaging and positron emission tomography with
18
F‐
THK
5351 in 10 subjects: five patients with
CBS
and five age‐matched normal controls (
NC
s).
Results
The 1‐year follow‐up scan images revealed that
18
F‐
THK
5351 retention had significantly increased in the superior parietal gyrus of the patients with
CBS
compared with the
NC
s. The median increases in
18
F‐
THK
5351 accumulation in the patients with
CBS
were 6.53% in the superior parietal gyrus, 4.34% in the precentral gyrus and 4.33% in the postcentral gyrus. In contrast, there was no significant increase in the regional
18
F‐
THK
5351 retention in the
NC
s.
Conclusions
Longitudinal increases in
18
F‐
THK
5351 binding can be detected over a short interval in the cortical sites of patients with
CBS
. A monoamine oxidase B binding radiotracer could be useful in monitoring the progression of astrogliosis in
CBS
.
A measurement of the B$_s^0$→J/ψϕ decay parameters using 80.5 fb-1 of integrated luminosity collected with the ATLAS detector from 13 Te proton–proton collisions at the LHC is presented. ...The measured parameters include the CP-violating phase ϕs, the width difference Δ Γs between the B$_s^0$ meson mass eigenstates and the average decay width Γs. The values measured for the physical parameters are combined with those from 19.2fb-1 of 7 and 8 Te data, leading to the following: ϕs=-0.087±0.036(stat.)±0.021(syst.)radΔΓs=0.0657±0.0043(stat.)±0.0037(syst.)ps-1Γs=0.6703±0.0014(stat.)±0.0018(syst.)ps-1Results for ϕs and Δ Γs are also presented as 68% confidence level contours in the ϕs–Δ Γs plane. Furthermore the transversity amplitudes and corresponding strong phases are measured. ϕs and Δ Γs measurements are in agreement with the Standard Model predictions.
To evaluate the mechanism of tolerance to ischemia, inductions of heat shock protein (HSP) 70 and heat shock cognate protein (HSC) 70 mRNAs in gerbil hippocampus were compared with in situ ...hybridization between cases of a single 3.5-min period of forebrain ischemia and a 3.5-min period of ischemia 2 days after 2-min pretreatment with ischemia. Immunohistochemistry for HSP70 protein and morphological studies were also performed in the same brains up to 7 days after the reperfusion. Following a single 3.5-min period of ischemia, HSP70 and HSC70 mRNAs were induced in all hippocampal cells. However, the hippocampal CA1 cells produced only a minimum of HSP70 protein, and the cells were almost lost by 7 days. Following 3.5 min of ischemia after 2-min pretreatment, large populations of the CA1 cells survived at 7 days. The peak time of the HSP70 and HSC70 mRNA induction shifted to an earlier period of reperfusion in all hippocampal cells as compared with the case of a single episode of ischemia. The peak of HSP70 and HSC70 mRNA induction shifted from 1 day to 3 h in the CA1 cells. The CA1 cells produced strongly immunoreactive HSP70 from 3 hr to 2 days. These results suggest that pretreatment with an initial period of ischemia (for 2 min) accelerated HSP70 and HSC70 gene expression at the transcriptional level, ameliorated the translational disturbance of HSP70 mRNA to protein, and saved the CA1 cells from subsequent lethal ischemia (for 3.5 min). These changes of heat shock gene expression might play important roles in the acquisition of ischemic tolerance of hippocampal CA1 neurons.
In this paper, we give a new proof of the Iwasawa main conjecture using the Euler systems of Gauss sums. Our proof is different from that of Mazur and Wiles and that of Rubin and Greither. Rubin's ...proof used the Euler systems of cyclotomic units and the plus part of the ideal class groups. Instead of cyclotomic units, we use the Euler systems of Gauss sums and directly study the minus part of the ideal class groups.
We examined the long-term effects of dietary diacylglycerol (DG) and triacylglycerol (TG) with similar fatty acid compositions on the development of obesity in C57BL/6J mice. We also analyzed the ...expression of genes involved in lipid metabolism at an early stage of obesity development in these mice. Compared with mice fed the high-TG diet, mice fed the high-DG diet accumulated significantly less body fat during the 8-month study period. Within the first 10 days, dietary DG stimulated β-oxidation and lipid metabolism-related gene expression, including acyl-CoA oxidase, medium-chain acyl-CoA dehydrogenase, and uncoupling protein-2 in the small intestine but not in the liver, skeletal muscle, or brown adipose tissue, suggesting the predominant contribution of intestinal lipid metabolism to the effects of DG. Furthermore, analysis of digestion products of 14CDG and those of 14CTG revealed that the radioactivity levels detected in fatty acid, 1-monoacylglycerol, and 1,3-DG in intestinal mucosa were significantly higher after intrajejunal injection of DG rather than TG.
Thus, dietary DG reduces body weight gain that accompanies the stimulation of intestinal lipid metabolism, and these effects may be related to the characteristic metabolism of DG in the small intestine.
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