A simple method has been developed for detecting a broad range of genital human papillomavirus (HPV) types using the polymerase chain reaction (PCR). We utilized two consensus sequence primer pairs within the E6 and E7 open reading frames to amplify HPV DNA; malignant HPV DNA (from HPV-16, -18, -31, -33, -52b and -58) was amplified using the pU-1M/ pU-2R primer pair whereas benign HPV DNA (from HPV-6 and -11) was amplified using the pU-31B/ pU-2R primer pair. Identification of the amplification product was confirmed by restriction enzyme digestion. In this study, a pU-1M/pU-2R-mediated PCR was successfully applied to 39 cervical carcinoma specimens; HPV-16 was detected in 19 cases, HPV-18 in five cases, HPV-31 in two cases, HPV-33 in two cases, HPV-52b in one case, HPV-58 in three cases, and an unknown type(s) was detected in four cases. Overall, the prevalence of HPV was 84.6 %. The results indicate that this detection system is useful for the detection of HPVs not only of known types but also of new types.
1. We examined the effects of habitat fragmentation caused by dams on freshwater fish species using a database of 7848 fish presence/absence surveys, conducted between 1953-2003 in Hokkaido, Japan. 2. A series of generalised linear models showed that for 11 of 41 taxa examined, the probability of occurrence had been influenced either negatively (eight taxa) or positively (three taxa) by the presence of a dam downstream from their habitat. 3. Maps of modelled predictions revealed that dams had had widespread negative impacts on certain taxa, while for other taxa the impact was limited to specific basins. Two of the three taxa whose probability of occurrence was increased in areas above dams have long been transplanted into reservoirs in Japan. 4. For four of the eight taxa whose probability of occurrence was reduced above dams and all three taxa whose probability of occurrence increased above dams, the temporal length of habitat isolation (i.e. the number of years between dam construction and sampling) was also a significant predictor of the probability of occurrence. This pattern indicates that these taxa experienced a gradual rather than an instantaneous population impact as a result of dam construction. 5. The eight taxa whose probability of occurrence was reduced as a consequence of dams all exhibit migratory life cycles. Although migratory taxa are probably more susceptible to the negative effect of dams, we could not detect significant relationships between migration life histories and the effect of fragmentation by dams. 6. These analyses enable stream and fisheries managers to quantify the impacts of habitat fragmentation because of dams for individual species. The spatially explicit nature of our analyses also enables identification of the areas of the impact at broad geographical scales. Using our results, managers can take effective conservation and restoration measures to predict, mitigate or remove the impact of dams. For example, our results can be used to prioritise dams for removal or to predict losses of biodiversity and ecosystem services in advance of dam construction.
We investigated aquatic macrophytes, water quality, and phytoplankton biomass and species composition in three shallow lakes with different levels of vegetation cover and nutrient concentration in Kushiro Moor, during August 2000. Trapa japonica can live in a wide range of nutrient levels. This species forms an environment with a steeper extinction of light, higher concentrations of dissolved organic carbon (DOC), lower concentrations of dissolved oxygen (DO) near the bottom, and lower concentrations of nitrate + nitrite and soluble reactive phosphorus (SRP) than other vegetation types. The pH was much higher in a Polygonum amphibium community, and the DO near the bottom did not decrease compared to a T. japonica community in the summer. The relationship between chlorophyll a and the limiting nutrient (total phosphorus (TP) when total nitrogen (TN) : TP is ≥10 and TN/10 when TN : TP is <10) significantly differed between lakes with and without submerged vegetation. The chlorophyll a concentrations at a given nutrient level were significantly lower in water with submerged macrophytes than in water without them. Correspondence analysis showed that the difference in phytoplankton community structure across sites was largely due to the presence or absence of submerged macrophytes, and the ordination of phytoplankton species in the lakes with submerged macrophytes is best explained by environmental gradients of TN, chlorophyll, pH and SRP.
This study investigated whether repeated use of limited spawning grounds (i.e., redd superimposition) by pink salmon (Oncorhynchus gorbuscha) can cause density-dependent mortality. Loss of eggs from part of Auke Creek, Alaska, was estimated from a series of mark-recapture experiments and maximum likelihood models. The number of eggs lost per day during the 5-week spawning season and for 2 weeks afterward was roughly proportional to spawner abundance and weakly related to stream discharge. Freshets after cessation of spawning induced negligible egg loss. The maximum daily egg loss estimated by one model was 398 000 eggs (80% CI = 267 000 - 1 581 000) or equivalently a loss of about 300 female spawners when the daily spawner abundance (both male and female) in the study area was at most 1000.
We examined the effects of dams on freshwater fish species based on data collected during 1990-2004 from 200 drainage systems in Japan. Of the 76 fish species examined, the occurrence of 20 species within Petromyzontidae, Cyprinidae, Cobitididae, Salmonidae, Cottidae, and Gobiidae was negatively affected by the presence of dams located in the downstream reaches of fish survey sites, whereas the occurrence of 12 species within Cyprinidae, Adrianichthyidae, Centrarchidae, and Gobiidae was positively associated with the presence of dams. A significantly higher proportion of the fishes with a negative damming effect were diadromous species as compared to the fishes with a positive damming effect. Conversely, the latter group had a significantly higher proportion of nonnative species than the former. A significant interaction existed between the effects of damming and the effects of elevation on family-specific species richness. Families dominated by native migratory species showed a greater reduction in the number of species above dams at lower elevations, whereas families represented primarily by nonnative species had higher species richness above dams at higher elevations, except for Centrarchidae, which was always higher in species richness above dams regardless of elevation. Based on our findings, dams in Japan have adversely affected native freshwater fishes by blocking their migration routes, favoring nonnative fishes, or altering existing habitats.
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