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991.
One of the difficulties to rear Anguilla japonica larvae is the frequent occurrence of notochord deformities. We tested the effect of salinity on the occurrence of the deformities, because we have been using 50 % diluted seawater (50 % SW) for glass eel production, on the basis of the fact that intermediate salinity saves energy due to lower cost for osmoregulation and contributes higher survival and growth rates. We reared 6-day-old larvae in 50 and 100 % SW for 85 days and observed their morphology. The occurrence rate of deformed larvae, including kyphosis and scoliosis, was significantly higher in 50 % SW (35.8 %) than in 100 % SW (25.4 %), while survival rate was significantly higher in 50 % SW (69.8 %) than in 100 % SW (32.3 %) and growth in 50 % SW (mean body depth: 7.9 ± 5.3 mm) was better than in 100 % SW (6.8 ± 4.6 mm). We speculate that the most of severely deformed larvae could not survive in the tougher condition of 100 % SW, showing the lower occurrence of deformed larvae. Eventually, the yield of normal larvae after 85 days rearing was 1.9-fold higher in 50 % SW than in 100 % SW, implying that the advantage of 50 % SW for rearing eel larvae outweighs the risk of deformities.  相似文献   
992.
Potato psyllid, Bactericera cockerelli (?ulc), causes economic damage to potato crops throughout the major potato growing regions of western North America. When cultivated crops are not available, potato psyllid often occurs on non-crop hosts. In the southern U.S. and northern Mexico, native species of Lycium (Solanaceae) are important non-crop hosts for the psyllid. We determined whether Old World species of Lycium now widespread in the Pacific Northwest are reservoirs of potato psyllid in this growing region. We examined Lycium spp. across a wide geographic region in Washington, Oregon, and Idaho at irregular intervals during three growing seasons. Potato psyllids were present at all locations. To determine whether Lycium is also a host during intervals of the year in which the potato crop is not available, we monitored a subset of these sites over the entire year. Six sites were monitored at 1- to 3-week intervals from June 2014 to June 2016. Psyllids were present on Lycium throughout the year at all sites, including during winter, indicating that Lycium is also a host when the potato crop is seasonally not available. Psyllid populations included a mixture of Northwestern and Western haplotypes. We observed well-defined spring and fall peaks in adult numbers, with peaks separated by long intervals in which psyllid numbers were very low. Seasonal patterns in psyllid numbers on these non-native Lycium hosts were very similar to what has been observed on native Lycium in the desert southwest region of the U.S. Our findings demonstrate that potato psyllid associates with Lycium across a broad geographic region within the Pacific Northwest. These results will assist in predicting sources of potato psyllid colonizing potatoes in this important growing region.  相似文献   
993.
This paper focuses on examining the dynamic nature of community supported agriculture (CSA) and the real-world experiences which mark its contours, often making it distinct from the early idealized CSA “model.” Specifically, our study examines the narratives of the farmers of Devon Acres CSA over its duration, in tandem with a survey of recent shareholders in order to understand and explain its evolution. The framework we develop here shows that this CSA is largely characterized by instrumental and functional beliefs and practices, with some elements in the collaborative mode. A key contribution of this research is the development of a framework which helps to highlight the relative fluidity and patchwork quality of CSA participant positions over time. At Devon Acres, the real-world factors and issues influencing CSA evolution are seen to be products of both the local and larger contexts, evident in such areas as shifts in farmer learning and adaptation, differences between beliefs and practices in member volunteer efforts, and changes in farm and resource conditions. With respect to CSA more broadly, we argue that the reality of dominant food system context and site-specific influences on CSA development compels us to rework our attachment to early idealized “model” traits. Expansion in CSA numbers, evidence of adaptation and situated learning, and retention of the local and organic as core traits, speak to the pragmatic yet transformative potential of CSA contribution to food system change.
Robert FeaganEmail:

Robert Feagan   PhD, is a faculty member in the interdisciplinary Contemporary Studies Program at the Brantford Campus of Wilfrid Laurier University in Ontario, Canada. His research and teaching interests are in local and regional food systems—farmers’ markets, CSAs, etc., in university–community partnerships, in community development, and in the green-burial movement. Ideas and objectives of “sustainability” underlie his many research directions. Amanda Henderson   earned a Masters Degree from the Faculty of Environmental Studies at York University in Toronto. She lives and works on a communal eco-farm in rural Ontario, Canada.  相似文献   
994.
In this paper, the orthogonal experimental method was carried out to optimize the curing process of aeronautical composite X850/T800 in autoclave process. Four important curing parameters including curing pressure, heating rate, curing temperature and heat preservation time were taken into account, and sixteen samples were fabricated to study the effects of the four parameters mentioned above on the curing quality by interlaminar properties test and microstructure analysis. The interlaminar properties and the interfacial bonding quality of these samples were studied by the short-beam three points bending test and scanning electron microscopy, respectively. Results revealed that the optimal curing process of X850/T800 composite laminate should be as follows: curing pressure of 0.6 MPa, heating rate of 1.5 °C/min, curing temperature of 160 °C, and heat preservation time of 120 min.  相似文献   
995.
Neosalanx taihuensis were sampled from the Tian-e-zhou Oxbow from March 2006 through November 2007. Two separate spawning seasons were identified based on the annual reproductive cycles of the females, designated as the autumn-spawning season and the spring-spawning season. Lifespan of the offspring of the spring-spawning fish was 1 year, with them dying after the subsequent spring spawning. Autumn-spawned females seem to be the offspring of the spring-spawning fish, based on monthly changes in the length–frequency distributions. Spring-mature females had higher absolute fecundity, gonadosomatic index, and relative condition factor in 2007 than in 2006. Relative condition factor of the immature female offspring of spring-spawning fish was higher in 2007 than in 2006, portending a further increase in reproductive investment during the spring spawning of 2008. The increasing reproductive investment suggests that the population of N. taihuensis in the Tian-e-zhou Oxbow may be recovering from its recent decline.  相似文献   
996.
Severe mottle necrosis (Shirogusare-byo in Japanese) was found on mature tubers of sweet potato (Ipomoea batatas) in Ibaraki Prefecture in October 2004. The causal organism was identified as Pythium scleroteichum hitherto unknown in Japan. Sweet potato cultivar Purple Sweet Lord was more susceptible than cultivars Beniazuma, Benimasari, Koukei-14, and Tamayutaka to the pathogen at 25°C, while this difference in the susceptibility was not clear at 15°C.  相似文献   
997.
Host immune responses conducted against antigens of Eimeria bovis are key factors for the development of protective immunity against this protozoan disease. In this study we investigated the expression of E. bovis-derived antigens on the host cell surface membrane during E. bovis first merogony in vitro. Host cells carrying E. bovis-meront I stages expressed E. bovis host cell surface antigens (EbHCSAg) on their surface membrane which were recognised by hyperimmune sera of calves and by sera from rats immunized with E. bovis merozoites I, when tested by indirect immune fluorescent antibody test (IIFAT), laser scanning confocal microscopy (LSCM) and immune electron microscopy. Expression of EbHCSAg on permissive host cells was earliest detected 7 days p. i., thus coinciding with the onset of the parasite replication. Membrane-associated EbHCSAg were removed from infected host cells by proteinase K, partially by Triton X-100, Triton X-114 and Triton X-405, but not by 1 M NaCl, CHAPS or phospholipase C treatment. Antibodies, affinity-purified on paraformaldehyde/glutardialdehyde (PAGA)-fixed E. bovis meront I-infected bovine host cells bound to the surface meront I-carrying cells and to merozoites I (IIFAT, LSCM) but, in contrast to untreated sera, not to sporozoites. When tested on methanol-fixed merozoites I and sporozoites by IIFAT, affinity-purified antibodies bound to structures in the apical complex area of merozoites I, but not to sporozoites, whilst untreated sera caused diffuse labelling of internal structures of both parasite stages. Immune electron microscopy demonstrated binding of affinity-purified antibodies to micronemes and dense granules of merozoites I. Although the function of EbHCSAg is still unknown, results of this study might suggest an involvement in the development of protective immunity against E. bovis infections.  相似文献   
998.
A carbonaceous sorbent was prepared from the wood of Japanese larch (Larix leptolepis) by dehydration with concentrated sulfuric acid in a 69% yield. The abilities of the sorbent to remove Cr(VI) from aqueous solutions were investigated. Research parameters included the initial solution pH, temperature, and initial concentration of Cr(VI) in solution. The removal of Cr(VI) was highly solution pH dependent and was mainly governed by physicochemical sorption under weak acidic conditions. The equilibrium data fit well in the Langmuir isotherm model. The Langmuir constants were calculated at different temperatures, and the sorption capacity increased with rising temperature, indicating the endothermic nature of the Cr(VI) sorption onto the sorbent. The desorption experiments suggest that the Cr(VI) sorption is generally irreversible, owing to strong interaction of HCrO 4 with the active sites of the sorbent.  相似文献   
999.

•Introduction  

In the context of climate change, assessing climate–growth relationships is of high importance in order to understand how forest ecosystems evolve and to test climate models at regional scale.  相似文献   
1000.

Objective

To evaluate the cardiorespiratory effects of a 7° reverse Trendelenburg position (RTP) in anaesthetized horses.

Study design

Randomized, non-blinded clinical trial.

Animals

A total of 125 horses undergoing elective surgery in dorsal recumbency.

Methods

Horses were allocated to one of three weight classes and assigned to be positioned either on a horizontal table or on a table in 7° RTP, according to a randomized block design. In all horses, anaesthesia was maintained with isoflurane in oxygen and a constant rate infusion of romifidine. All horses were mechanically ventilated throughout anaesthesia, and routine cardiovascular monitoring and arterial blood gas analysis were performed at 15-minute intervals and relevant variables calculated. Data from the first 60 minutes of anaesthesia were compared between both positions using a mixed model analysis of variance.

Results

A significant interaction was found between position and weight class for the alveolar to arterial oxygen tension gradient and F-shunt: these variables were lower in RTP than in horizontal position in the two lowest weight classes and vice versa in the highest weight class. Arterial oxygen tension and oxygenation indices were significantly worse in the horses in the higher weight classes.

Conclusions and clinical relevance

A 7° RTP did not result in clinically relevant changes in gas exchange or cardiovascular function. Horses with a higher body weight are at increased risk for hypoxaemia during anaesthesia in dorsal recumbency.  相似文献   
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