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1.
Many populations of Heterodera rostochiensis mostly from the main potato growing areas of England and Wales, were tested with eelworm-resistant potato varieties (andigena hybrids). Except in the Eastern Region, where resistant varieties were planted alongside commercial varieties in infested fields, tests were done in pots inoculated with a standard number of cysts extracted from a single soil sample from each field. The tests showed that England and Wales could be divided into areas according to the percentage of cysts(< 10%, 11–70%,> 70%) produced on the resistant compared with a commercial non-resistant variety. On the peat soils of the East Anglian fens and in Bedfordshire, Essex and Kent (area A) most populations produce few cysts on resistant varieties. In much of the East Midlands and Yorkshire (area D), populations produce many cysts on resistant varieties which behave much as ordinary susceptible potatoes. Populations in the rest of England and Wales (areas B, C) vary and in many districts every field must be tested separately. If the pathotypes occurring in Britain had separate origins in South America, the present distribution in England and Wales is probably due to chance introductions dispersed with seed and following the patterns of trade in seed potatoes. As all commercial varieties, before the release of eelworm-resistant ones, were about equally susceptible to the different pathotypes, the varieties themselves probably played little part in determining the present distribution of pathotypes.  相似文献   

2.
Analysis of data from the National Soil Inventory of England and Wales obtained between 1978 and 2003 shows widespread increases in soil pH – i.e., soils became less acid – across both countries during the survey period. In general, soil pH increased under all land uses. At least part of the increase and its regional variation could be explained by decreased sulphur deposition from the atmosphere. Changes in liming practices on arable land probably also contributed. The effect of decreased sulphur deposition was moderated by land use, soil properties – particularly soil pH and organic carbon content – and the level of past sulphur deposition.  相似文献   

3.
Routine sources of data on chickenpox morbidity and mortality in England and Wales were reviewed for 1967-85. Only two epidemics occurred, one in 1967 and one in 1980, both of which were immediately followed by two to three years of low incidence. The age distribution of the disease appears to be changing, with more cases now being reported in children aged 0-4 years. The number of deaths in adults have, however, increased, particularly those deaths that are associated with pneumonia and immunosuppression. At present in England and Wales more deaths are attributed to chickenpox than to whooping cough and mumps.Widespread use of selective immunisation against chickenpox might be justified in England and Wales, but before routine immunisation of the child population can be considered special surveys to determine the incidence and severity of chickenpox and the effect of the vaccine on the subsequent development of herpes zoster are needed as well as cost-benefit studies of immunisation.  相似文献   

4.
5.
Abstract. 1. Estimates of the relative crypsis of the melanic and typical morphs of B.betularia have been made at fifty-two sites in southern England and south Wales and these estimates were compared with melanic frequencies in samples from these sites.
2. The decrease from east to west in the frequency of the melanic form, carbonaria , and increase in the frequency of a second melanic form, insularia , across the southern part of England and Wales is largely independent of changes in smoke concentration, sulphur dioxide concentration or relative crypsis.
3. When all the available information on the distribution of the melanics of B.betularia is considered, sulphur dioxide concentration is correlated with the geographic variation in carbonaria frequency. This, together with evidence of the close relationship between carbonaria crypsis and sulphur dioxide levels, indicates that outside southern England and south Wales, either selective predation, or some direct selective effect of pollutants, is of major importance in determining the variation in carbonaria frequency.
4. Some features of the pattern of the spread of carbonaria in England and Wales during the last century give reasons for expecting non-industrial selective factors to be of greater importance in determining the distribution of melanics of B.betularia in southern England and south Wales than in the rest of Britain.  相似文献   

6.
Probably in response to recent changes in habitat structure, populations of a number of species of deer are increasing both in numbers and in geographical distribution in lowland Britain. In the wake of this expansion there is increasing awareness and concern over damage to agriculture/horticulture and forestry, as well as damage to sensitive vegetation in conservation areas. Despite a perception that damage levels are rising, data that actually quantify the scale of impact by deer on lowland agriculture and forestry interests or conservation habitats are scarce. This review attempts to draw together such objective data as are available to assess more formally the actual impact of deer damage in these different contexts and the economic significance of damage caused. The review concludes with a brief consideration of implications for management. The majority of agricultural damage reported in England and Wales was due to Fallow, Red and Roe Deer; Muntjac were only implicated in a little horticultural damage where they are numerous. Most reports were of damage to pasture or cereals, with oilseed rape, nursery and orchard crops also frequently damaged. Because of fundamental differences in ecology and distribution, different species of deer were implicated in different types of damage, depending on feeding habit and distribution in relation to geographical patterns of crop-type. In a woodland context, Fallow, Red and Roe Deer were implicated in the majority of reported damage in lowland UK, which is most frequent in the north of England and lowest in Wales. Despite the apparent severity of damage caused to agriculture or forestry, the actual economic significance of such damage would appear in many cases to be negligible or small. Field crops frequently recover completely from such damage, and although woodland crops may be checked and quality of the timber may be reduced as a consequence of earlier browsing damage, losses may be far less than they first appear. This whole question of the true economic cost of deer damage needs further research. Deer damage to conservation habitats in England and Wales appears largely restricted to woodland; impact on heathlands, grasslands and wetlands is generally welcomed as helping to arrest invasion of scrub. Within woodlands, while concern is expressed in a small number of cases over losses of sensitive ground flora or suppression of natural regeneration, the major problem is in damage to coppice regrowth on sites where coppice management has been recently reintroduced.  相似文献   

7.
Seven different measurements of fox skulls from animals of known sex were recorded for 571 fox skulls from Wales and South-East England. A multivariate technique, discriminant function analysis, is used to classify the skulls according to sex and regional origin. Differences detected suggest that male skulls tend to be larger, and that skulls from Wales are larger than those from South-East England. The classifications are presumed to reflect true differences between sexes and regions.  相似文献   

8.
In England and Wales hospital admissions for childhood asthma almost trebled over the period 1975-81. This may have reflected a true increase in the incidence of acute asthma, a swing from primary to hospital care, or both. The trend was not due to a change in diagnostic fashion. Monthly admissions showed a pronounced seasonal variation with fewest admissions in winter, rising in spring and early summer to peak in the autumn. A deep admission trough was present in August. The monthly admission profile was very similar throughout England and Wales, suggesting that major "trigger" factors were responsible.  相似文献   

9.
The incidence and the clinical course of patients suffering from sickle-cell syndrome (Hb SS; Hb SC; Hb S thal) in England and Wales are not known. In 1979 an ad hoc committee was formed to investigate these problems. Initially, a questionnaire was sent to 227 haematologists in England and Wales to determine the number of cases in these countries. The replies have indicated that 1367 cases were seen in 1978 and 1979. Probably this may represent only half the total number of cases. From this survey it has been possible to draw up a composite map showing the location of patients, which has provided a basis to determine the clinical course of the disease, and for further studies into the complications and management of sickle-cell disease in England and Wales. From a second questionnaire preliminary data about the general management and mortality in England and Wales have been recorded.  相似文献   

10.
Two pathotypes of the cereal cyst-eelworm (Heterodera avenae), occurred commonly in England and Wales and a third pathotype was apparently present in low numbers in a few areas. Pathotype 1, which can breed on most cultivars of wheat, barley and oats, but not on Drost barley nor barley cultivars containing the gene for resistance from barley No. 191, was most common in the south west of England. Pathotype 2, which can breed on most cereals, including Drost barley but not No. 191, was common throughout England and Wales and mixtures of these pathotypes occurred in many places. Pathotype 3, which can breed on barley No. 191 and probably on Drost and most cultivars of cereals, was rare and was found only in low numbers together with either or both Pathotypes 1 and 2. In the initial tests it was present or suspected in only nine fields (6%), but when these soils were retested in more detail the following year, Pathotype 3 was confirmed at only one site.  相似文献   

11.
OBJECTIVE--To assess the prevalence of antibiotic resistance and serotype distribution among pneumococci in England and Wales in 1990 and 1995. DESIGN--Observational surveys in March 1990 and March 1995. During two weeks in each survey period all pneumococci isolated in public health laboratories in England and Wales were collected and assessed for sensitivity to antibiotics and the distribution of serogroups or serotypes. SETTING--The network of public health laboratories throughout England and Wales. SUBJECTS--1127 individual patient isolates of Streptococcus pneumoniae obtained during the two surveys. MAIN OUTCOME MEASURES--Sensitivity or resistance to a range of antibiotics; serogroup or serotype. RESULTS--The prevalence of intermediate or full resistance to penicillin increased from 1.5% in 1990 to 3.9% in 1995 and resistance to erythromycin increased from 2.8% to 8.6%. About 92% of isolates belonged to serogroups or serotypes included in the currently available pneumococcal vaccine. CONCLUSION--Resistance to penicillin and erythromycin has increased among pneumococci in England and Wales. Continued surveillance to assess further increases in the prevalence of pneumococcal resistance to antibiotics is essential.  相似文献   

12.
Australian isolates (79) of Salmonella enterica subsp. enterica serovar Virchow ( Salmonella Virchow) were characterized by phage typing. Thirteen phage types were identified, of which phage type (PT) 8, representing 54 of 79 isolates, was predominant, as it had been in England and Wales up to 1994 when it was replaced by PT26. Other phage types identified in Australia were distinct from those observed in England and Wales. This suggests that PT8 may be a global phage type, while others may be distinct to particular geographical regions.  相似文献   

13.
In field trials at eight sites throughout the UK the mean thermal time requirement for navy beans from sowing to harvest for a standard cultivar, Marcus, was 2069 Ontario Heat Units (OHU). Low level plastic covers increased the range of warm environments at one site and gave a mean thermal time required of 2098 OHU. Analysis of daily air temperatures from six weather stations throughout the UK over a 29 year period, showed a 14 day possible planting period on the south coast of England, but gave a high probability of crop failure in Scotland. Maps of England and Wales indicating the probability of achieving 2000 OHU were produced from 5 km grid point temperatures. Less than 2% of the land had more than a 60% chance of receiving 2000 OHU under the present climate, however this area increased to 70% with a mean temperature rise of 1.5°C. Although 2000 OHU is often used as the thermal time requirement of navy beans, these trials showed that it may be more accurate to use the higher figure of 2087 OHU from sowing to harvest, and restrict the use of 2000 OHU to the period between emergence and harvest. When the map was redrawn using 2087 OHU and current climate, no parts of England and Wales showed a reasonable chance of growing the present cultivars of navy beans.  相似文献   

14.
Trends in mortality attributed to asthma in the 5-34-year age group were examined in New Zealand, Australia, England and Wales, the United States, Canada, and West Germany for the years 1959-79. An epidemic of deaths from asthma occurred in the mid-1960s in New Zealand, Australia, and England and Wales but not in the other countries. In Australia and England and Wales the death rate quickly returned to pre-epidemic levels, but in New Zealand the decline in mortality was slow, and by 1974 the death rate was still almost double the pre-epidemic level. Of great concern was an abrupt increase in reported deaths from asthma in New Zealand after 1976 with the mortality rate during 1977-9 being greater than during the previous epidemic. In contrast, asthma mortality had remained relatively stable in the other populations.The new epidemic in New Zealand was investigated and appeared to be real. It could not be explained by changes in the classification of deaths from asthma, inaccuracies in death certification, or changes in diagnostic fashions. The most likely explanation appeared to be related to the management of asthma in New Zealand, and this is being investigated.  相似文献   

15.
Observations on siting, dimensions and structure of salmonid redds   总被引:3,自引:0,他引:3  
Redds of trout, Salmo trutta L., Atlantic salmon, S. salar L., and rainbow trout, S. gairdneri Richardson, were studied at sites in north-east England, south-west Wales and southern England (Dorset). Spawning females preferred gravels of 20–30 mm diameter and water velocities at 0·6 depth of 15 cm s-1 and < c. 2·0 body lengths s-1. After logarithmic transformation the major horizontal dimensions of redds could be related to one another by linear regressions, and redd tail length could, similarly, be related to female fish length. Egg burial depth in upland stony streams in north-east England and south-west Wales could be predicted from a linear regression of mean depth upon female length. Information is also given on gravel composition and redd structure.  相似文献   

16.
Acid atmospheric deposition can cause losses of metal nutrients from the organic layer of a soil. The size of these losses depend on the sizes of the different pools in which the metals are present, as these pools differ in mobility. The metal pools in an organic soil layer of a Douglas fir forest in the Netherlands subjected to acid deposition were determined by means of extractions and percolations. Na was mainly dissolved and exchangeably adsorbed, K dissolved, exchangeably adsorbed and present in the soil microbial biomass, Ca exchangeably adsorbed and present in organic precipitates, Mg exchangeably adsorbed and present in the soil biomass, and Mn exchangeably adsorbed and present in inorganic precipitates. The main part of the metals was exchangeably adsorbed. The adsorption affinity increased in the order Na < K < Mg < Mn ≈ Ca. The vertical distribution of the metals in the organic layer showed that all metals were continuously lost from the organic layer. The differences between the metals in retention and vertical distribution patterns were in agreement with their differences in deposition rate, pool distribution, and exchange affinity. Since the metals were mainly exchangeably adsorbed, and the acidifying cations dominated the atmospheric deposition, acid deposition and cation exchange must be processes that strongly affect the losses of metals from this organic soil layer. R F Huettl Section editor  相似文献   

17.
In England and Wales between 1951 and 1980 233 reported outbreaks of communicable disease attributed to milk or dairy products affected nearly 10 000 people, of whom four died. Tuberculosis and brucellosis have been controlled, but milk-borne outbreaks of salmonellosis and campylobacter enteritis due to raw or defectively pasteurised milk are common and may be increasing in number. Universal heat treatment of milk is an effective preventive measure, and it is regrettable that the continued sale of untreated milk is to be permitted in England and Wales.  相似文献   

18.
A recent report of widespread declines in soil organic C (SOC) in the UK over the 10–25 years until the early 2000s has focussed attention on the importance of resampling previously characterized sites to assess long‐term trends in SOC contents and the importance of soils as a potentially volatile and globally significant reservoir of terrestrial C. We have used two sets of long‐term experimental plots which have been under constant and known management for over a century and for which historical data exist that allow comparison over recent decades to determine what, if any, changes in SOC content have occurred. The plots used are the Palace Leas (PL) Meadow Hay Plots in north‐east England (UK) established in 1897, and from the Park Grass (PG) Continuous Hay experiment established in 1856 at Rothamsted in south‐east England. Collectively, these plots represent the only grassland sites in the UK under long‐term management where changes in SOC over several decades can be assessed, and are probably unique in the world. The plots have received different manure and fertilizer treatment and have been under known management for at least 100 years. In 1982, total SOC contents were determined for the 0–27 cm layer of six of the PL plots using measurements of SOC concentrations, bulk density and soil depth. In 2006, the same six PL plots were resampled and SOC contents determined again. Four of the plots showed no net change in SOC content, but two plots showed net loss of SOC of 15% and 17% (amounting to decreases of 18 and 15 t C ha?1) since 1982. However, these differences in total SOC content were in a similar range to the variations in bulk density (6–31%) with changing soil water content. In 1959, the soil masses and SOC concentrations to 23 cm depth were measured on six PG plots with fertilizer and manure treatments corresponding closely with those measured on PL. In 2002, the SOC concentrations on the same plots were measured again. On three of the PG plots, SOC concentrations had declined by 2–10%, but in the other three it had increased by 4–8% between 1959 and 2002. If it is assumed that the soil bulk density had not changed over this period, the losses of SOC from the top soils ranged range from 10 to 3 t C ha?1, while the gains ranged from 4 to 7 t C ha?1. When the differences with time in SOC contents for the six PL and the six PG plots were examined using paired t‐tests, that is, regarding the plots as two sets of six replicate permanent grasslands, there were no significant differences between 1982 and 2006 for the PL plots or between 1959 and 2002 for the PG plots. Thus, these independent observations on similar plots at PL and PG indicate there has been no consistent decrease in SOC stocks in surface soils under old, permanent grassland in England in recent decades, even though meteorological records for both sites indicate significant warming of the soil and air between 1980 and 2000. Because the potential influences of changes in management or land use have been definitively excluded, and measured rather than derived bulk densities have been used to convert from SOC concentrations to SOC amounts, our observations question whether for permanent grassland in England, losses in SOC in recent decades reported elsewhere can be attributed to widespread environmental change.  相似文献   

19.
Data from the Hospital In-patient Enquiry were used to define the regional patterns of hospital discharge rates for upper urinary tract stones and renal colic in England and Wales. By combining the rates for stones and colic, and by distinguishing emergency from planned admissions, the biases produced by repeated admissions of the same patient and by regional variations in diagnosis and coding may be reduced. There are regional variations in incidence of upper urinary tract stones: Wales and the southern regions of England have a generally higher incidence than northern regions. These variations may be related to regional differences in diet or occupation; or they may partly depend on associations between stone incidence and atmospheric temperature, exposure to ultraviolet irradiation, and hardness of drinking water.  相似文献   

20.
Analysis of perinatal mortality attributed to congenital malformations in England and Wales, using data from birth and death registration over the years 1974-81 showed significant declines in England and Wales as a whole and in the individual Regional Health Authority (RHA) areas. A greater decrease in death rate from congenital malformations, particularly central nervous system malformations, was seen among stillbirths than among early neonatal deaths. There were marked regional differences in perinatal mortality due to central nervous system malformations over the period but not in cardiovascular system malformations or in other malformations. The highest mortality rates due to central nervous system malformations occurred in the North, North-West, West and South-West of England and in Wales, and the lowest rates in the South and South-East. The larger percentage reductions in the mortality rates were found in most of the regions which had had the highest rates. Possible explanations for the decline in regional rates are suggested.  相似文献   

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