The influences of boiling and drying treatments on the behaviors of tension wood with gelatinous layers in <Emphasis Type="Italic">Zelkova serrata</Emphasis>     

Kentaro Abe  Hiroyuki Yamamoto 《Journal of Wood Science》2007,53(1):5-10

This study examined how boiling and drying treatments influenced various physical properties of the tension wood with gelatinous fibers (G-fibers) of a 29-yearold Zelkova branch. By boiling treatment, tension wood with numerous G-fibers contracted considerably in the longitudinal direction and the longitudinal Young’s modulus decreased in spite of the water-saturated condition. The drying treatment caused green tension wood and boiled tension wood with numerous G-fibers to shrink longitudinally and increased their longitudinal Young’s moduli. These specific behaviors in tension wood were highly correlated with the proportion of G-fibers in a specimen and were probably caused by the microscopic behavior of cellulose microfibril (CMF) in the gelatinous layers (G-layers). The longitudinal shrinkage of tension wood due to drying suggests the existence of a hygro-sensible, noncrystalline region in the CMF, which is abundant in the G-layer. Furthermore, the noncrystalline region in the CMF softens during boiling treatment, resulting in the reduction of the longitudinal Young’s modulus in tension wood. The longitudinal contraction of tension wood with G-fibers by boiling might be caused by the tensile growth stress remaining in green G-layers. However, no changes were detected in the 004 d-spacing of cellulose crystal in tension wood from the boiling and drying treatments, regardless of the proportion of G-fibers.  相似文献   

Assessing the influence of mechanical ventilation on blood gases and blood pressure in rattlesnakes          下载免费PDF全文

Mads F Bertelsen  Rasmus Buchanan  Heidi M Jensen  Cleo AC Leite  Augusto S Abe  Søren S Nielsen  Tobias Wang 《Veterinary anaesthesia and analgesia》2015,42(4):386-393

ObjectiveTo characterize the impact of mechanical positive pressure ventilation on heart rate (HR), arterial blood pressure, blood gases, lactate, glucose, sodium, potassium and calcium concentrations in rattlesnakes during anesthesia and the subsequent recovery period.Study designProspective, randomized trial.AnimalsTwenty one fasted adult South American rattlesnakes (Crotalus durissus terrificus).MethodsSnakes were anesthetized with propofol (15 mg kg⁻¹) intravenously, endotracheally intubated and assigned to one of four ventilation regimens: Spontaneous ventilation, or mechanical ventilation at a tidal volume of 30 mL kg⁻¹ at 1 breath every 90 seconds, 5 breaths minute⁻¹, or 15 breaths minute⁻¹. Arterial blood was collected from indwelling catheters at 30, 40, and 60 minutes and 2, 6, and 24 hours following induction of anesthesia and analyzed for pH, PaO₂, PaCO₂, and selected variables. Mean arterial blood pressure (MAP) and HR were recorded at 30, 40, 60 minutes and 24 hours.ResultsSpontaneous ventilation and 1 breath every 90 seconds resulted in a mild hypercapnia (PaCO₂ 22.4 ± 4.3 mmHg [3.0 ± 0.6 kPa] and 24.5 ± 1.6 mmHg [3.3 ± 0.2 kPa], respectively), 5 breaths minute⁻¹ resulted in normocapnia (14.2 ± 2.7 mmHg [1.9 ± 0.4 kPa]), while 15 breaths minute⁻¹ caused marked hypocapnia (8.2 ± 2.5 mmHg [1.1 ± 0.3 kPa]). Following recovery, blood gases of the four groups were similar from 2 hours. Anesthesia, independent of ventilation was associated with significantly elevated glucose, lactate and potassium concentrations compared to values at 24 hours (p < 0.0001). MAP increased significantly with increasing ventilation frequency (p < 0.001). HR did not vary among regimens.Conclusions and clinical relevanceMechanical ventilation had a profound impact on blood gases and blood pressure. The results support the use of mechanical ventilation with a frequency of 1–2 breaths minute⁻¹ at a tidal volume of 30 mL kg⁻¹ during anesthesia in fasted snakes.  相似文献   

Seed germination and seedling establishment of the monocarpic dwarf bamboo Sasa veitchii var. hirsuta     

Yuhei Abe  Shozo Shibata 《Journal of Forest Research》2014,19(1):166-173

In order to determine the influences of environmental factors on seed germination and to identify the effects of germination characteristics on seedling establishment for Sasa veitchii var. hirsuta, germination experiments and a survey on current seedling dynamics were conducted in a natural habitat after mass flowering. The results of the germination experiments revealed that the seeds require a low-temperature environment for germination; those exposed to low-temperature conditions for a time similar to the length of winter (4 months of low-temperature conditions) germinated gradually, while those exposed for longer (>4 months of low-temperature conditions) germinated rapidly. These results were compatible with field observations indicating that seedlings emerged from June to October in the year after mass flowering, and they suggested this germination characteristic (i.e., variation of germination timing due to seed dormancy) may play an ecological function in spreading risk (although it may also increase the potential for seed predation). The results also revealed that stronger light and alternating temperature conditions had no effect on germination, whereas high temperatures and drying had negative effects. The outcomes of the survey on current seedling dynamics revealed that the seedling establishment ratio was high in a forest understory compared to that seen at a site where solar radiation was strong and soil water content was low. This implies that germination characteristics may promote seedling establishment in forest understory.  相似文献   

Effect of improvement cutting on the community structure of aphyllophoraceous fungi on Okinawa Island     

Satoshi Yamashita  Tsutomu Hattori  Shin Abe  Hideaki Goto  Hiroki Sato 《Journal of Forest Research》2014,19(1):143-153

Improvement cutting, which decreases tree density by cutting and thinning while leaving logging residues, has been practiced on Okinawa Island since the 1970s and changes not only the vegetation composition but also the amount and composition of woody debris on the forest floor. To quantitatively compare the effect of improvement cutting with the effects of woody debris and vegetation on the community structure of aphyllophoraceous fungi, we conducted a field survey of vegetation composition, the amount and composition of woody debris, and the aphyllophoraceous fungi flora on Okinawa Island in December 2006. We established 3 plots in forest stands without logging and 13 plots in a forest that had undergone improvement cutting from 1 to 22 years before our field survey. The number and volume of woody debris tended to be highest soon after improvement cutting. We recorded 1,172 fungal samples belonging to 81 species in four orders. Fungal species richness was correlated with the composition of the woody debris. Fungal species composition in forest plots 1 year after improvement cutting differed from most of the other logged forests. Variation partitioning revealed that the effects of improvement cutting explained 14.1 % of the total variation in fungal species composition, and that differences in woody debris and vegetation not related to improvement cutting explained 40.4 %. Changes in the composition of woody debris caused by improvement cutting explained at most 2.7 % of the variation. This suggests that improvement cutting does not have a strong effect on fungal community structure, but woody debris does.  相似文献   

Changes in estrogen receptor expression in the chick thymus during late embryonic development     

Masafumi Katayama  Tomokazu Fukuda  Toshimitsu Hatabu  Kiyoaki Narabara  Asaki Abe  Yasuhiro Kondo 《Animal Science Journal》2014,85(3):277-285

In chickens, although estrogen receptors (ER) are reported to be associated with the immunological processes, detailed information about the differences in ER expression in the tissues related to the development of lymphocytes is not fully known, especially during the developmental stage. To learn more about this immunological relationship, we used semi‐quantitative polymerase chain reaction method to detect the ER expression levels in the thymus tissues of chicks during the developmental stage. Furthermore, ER‐expressing cells were detected by immunohistochemistry. The results of this study show that the expression level of ER increased on embryonic day 16 and decreased on day 20. Furthermore, ER expression was significantly higher in male than in female chickens at day 16. The increased expression on day 16 and decreased level on day 20 were also reproduced in the incidence of immunoreactive cells, although there was a 1‐day delay in the elevated incidence of the cells. This study revealed the changes in ER expression and the incidence of ER‐positive cells in the thymus of chickens during the developmental stage.  相似文献   

Sex reversal and nursery growth of Nile tilapia, Oreochromis niloticus (L.), free-swimming in earthen ponds     

R P Phelps  G Conterras Salazar  V Abe  B J Argue 《Aquaculture Research》1995,26(4):293-295

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Evaluating the impact of COVID-19 on ex-vessel prices using time-series analysis     

Abe  Keita  Ishimura  Gakushi  Baba  Shinya  Yasui  Shota  Nakamura  Kosuke 《Fisheries Science》2022,88(1):191-202

The spread of coronavirus disease 2019 (COVID-19) and subsequent lockdown measures have impacted economies and industries worldwide. The fisheries industry witnessed a sharp decline in demand and a slump in fish prices due to its dependence on the food service industry. It is important to quantitatively assess those fish species affected most and the extent of the pandemic’s impact on them, to take specific countermeasures. We propose a time-series analysis as an alternative to the current practice of using ad hoc year-on-year comparisons. Although the pandemic makes it difficult to construct a counterfactual approach due to the lack of an appropriate control group, we use time-series forecasting to simulate normal conditions using pre-pandemic data. In Tokyo, the unit price of fish species that were negatively impacted by the food services industry dropped by 12.65% to 14.64%, and by 26.08% to 28.22% after the declaration of a state of emergency. Seasonality, short weekly cycles, and short-term market trends are factors that affect the price of fish. Species-specific impact estimates related to the COVID-19 pandemic can allow policymakers to implement recovery measures in a more targeted and effective manner. The results of our analysis can increase fishers’ and policymakers’ awareness of the usefulness of economic analyses and incentivize them to release data to establish a system to accumulate and analyze data strategically for urgent and appropriate interventions in the fisheries industry.

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Fish meal vs. corn gluten meal as a protein source for dry cat food.     

M Funaba  T Tanak  M Kaneko  T Iriki  Y Hatano  M Abe 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(12):1355-1357

To compare the effects of two dietary protein sources, fish meal (FM) and corn gluten meal (CGM), fecal moisture content, nitrogen balance and urinary excretion were examined in adult cats. The dietary protein source did not cause a significant difference in daily food intake, water intake, urine volume, dry matter digestibility or urinary nitrogen excretion, but fecal moisture content was lower (P<0.02) in the CGM group. The HCl-insoluble fraction of urinary sediment tended to be higher in the CGM group (P<0.10), although urinary pH was similar in the two groups. These results suggest that CGM is comparable with FM in respect to nutritional value and the urine acidifying effect, but FM may be preferable to CGM for the prevention of constipation and struvite urolithiasis in cats.  相似文献   

Resetting central and peripheral circadian oscillators in transgenic rats     

Yamazaki S  Numano R  Abe M  Hida A  Takahashi R  Ueda M  Block GD  Sakaki Y  Menaker M  Tei H 《Science (New York, N.Y.)》2000,288(5466):682-685

In multicellular organisms, circadian oscillators are organized into multitissue systems which function as biological clocks that regulate the activities of the organism in relation to environmental cycles and provide an internal temporal framework. To investigate the organization of a mammalian circadian system, we constructed a transgenic rat line in which luciferase is rhythmically expressed under the control of the mouse Per1 promoter. Light emission from cultured suprachiasmatic nuclei (SCN) of these rats was invariably and robustly rhythmic and persisted for up to 32 days in vitro. Liver, lung, and skeletal muscle also expressed circadian rhythms, which damped after two to seven cycles in vitro. In response to advances and delays of the environmental light cycle, the circadian rhythm of light emission from the SCN shifted more rapidly than did the rhythm of locomotor behavior or the rhythms in peripheral tissues. We hypothesize that a self-sustained circadian pacemaker in the SCN entrains circadian oscillators in the periphery to maintain adaptive phase control, which is temporarily lost following large, abrupt shifts in the environmental light cycle.  相似文献   

Cartilage acidic protein-1B (LOTUS), an endogenous Nogo receptor antagonist for axon tract formation     

Sato Y  Iketani M  Kurihara Y  Yamaguchi M  Yamashita N  Nakamura F  Arie Y  Kawasaki T  Hirata T  Abe T  Kiyonari H  Strittmatter SM  Goshima Y  Takei K 《Science (New York, N.Y.)》2011,333(6043):769-773

Neural circuitry formation depends on the molecular control of axonal projection during development. By screening with fluorophore-assisted light inactivation in the developing mouse brain, we identified cartilage acidic protein-1B as a key molecule for lateral olfactory tract (LOT) formation and named it LOT usher substance (LOTUS). We further identified Nogo receptor-1 (NgR1) as a LOTUS-binding protein. NgR1 is a receptor of myelin-derived axon growth inhibitors, such as Nogo, which prevent neural regeneration in the adult. LOTUS suppressed Nogo-NgR1 binding and Nogo-induced growth cone collapse. A defasciculated LOT was present in lotus-deficient mice but not in mice lacking both lotus- and ngr1. These findings suggest that endogenous antagonism of NgR1 by LOTUS is crucial for normal LOT formation.  相似文献