scholarly journals Dispersal of Potato Cyst Nematodes Measured Using Historical and Spatial Statistical Analyses

2012 ◽  
Vol 102 (6) ◽  
pp. 620-626 ◽  
Author(s):  
N. C. Banks ◽  
M. Hodda ◽  
S. K. Singh ◽  
E. M. Matveeva
Keyword(s):  
Control Strategies ◽  
Potato Cyst Nematodes ◽  
Cyst Nematodes ◽  
Detection Distance ◽  
Rate Of Spread ◽  
Linear Distance ◽  
Straight Line ◽  
Constant Rate ◽  
Straight Line Distance ◽  
Road Distance

Rates and modes of dispersal of potato cyst nematodes (PCNs) were investigated. Analysis of records from eight countries suggested that PCNs spread a mean distance of 5.3 km/year radially from the site of first detection, and spread 212 km over ≈40 years before detection. Data from four countries with more detailed histories of invasion were analyzed further, using distance from first detection, distance from previous detection, distance from nearest detection, straight line distance, and road distance. Linear distance from first detection was significantly related to the time since the first detection. Estimated rate of spread was 5.7 km/year, and did not differ statistically between countries. Time between the first detection and estimated introduction date varied between 0 and 20 years, and differed among countries. Road distances from nearest and first detection were statistically significantly related to time, and gave slightly higher estimates for rate of spread of 6.0 and 7.9 km/year, respectively. These results indicate that the original site of introduction of PCNs may act as a source for subsequent spread and that this may occur at a relatively constant rate over time regardless of whether this distance is measured by road or by a straight line. The implications of this constant radial rate of dispersal for biosecurity and pest management are discussed, along with the effects of control strategies.

scholarly journals Does Distance Still Matter For Internal Migration And, If So, How? Evidence From 1986 To 2006

2015 ◽  
Author(s):  
Omoniyi Alimi ◽  
David Mare ◽  
Jacques Poot
Keyword(s):  
Travel Time ◽  
Internal Migration ◽  
Urban Areas ◽  
Goodness Of Fit ◽  
Socioeconomic Differences ◽  
Straight Line ◽  
Straight Line Distance ◽  
Deterrence Effect ◽  
Migration Flows ◽  
Road Distance

In this paper we re-examine the structure of internal migration flows in New Zealand.  We use data on gross migration flows between the 39 main and secondary urban areas for the four intercensal periods between 1986 and 2006.  We confirm that the gravity model – in which migration is inversely related to distance – fits the data well, and that the way in which distance is measured (travel time, road distance or straight-line distance) matters to some extent for the goodness of fit of the model. We also show that some forms of socioeconomic differences influence migration in the same way as distance. Perhaps surprisingly, we find that the deterrence effect of distance on migration was increasing, at least until 2001. Improvements in connectivity through reduced travel time have not increased migration flows. 

Conventional and real-time PCR-based species identification and diversity of potato cyst nematodes (Globodera spp.) from Victoria, Australia

Nematology ◽  
2008 ◽  
Vol 10 (4) ◽  
pp. 471-478 ◽  
Author(s):  
Lila Nambiar ◽  
James Cunnington ◽  
Motiul Quader
Keyword(s):  
Sequence Analysis ◽  
Real Time ◽  
Real Time Pcr ◽  
Binding Sites ◽  
Sequence Variation ◽  
Control Strategies ◽  
Globodera Pallida ◽  
Pcr Analysis ◽  
Potato Cyst Nematodes ◽  
Cyst Nematodes

AbstractPCR (conventional and real-time) and DNA sequence analysis were used to identify species and genotypes of potato cyst nematodes from sites in Victoria, Australia. Only Globodera rostochiensis was detected. Sequence analyses of these isolates of PCN have confirmed the PCR-based results and have revealed the presence of genetically diverse populations in infested fields. However, the sequence variation was not in the diagnostic primer binding sites. The melting peaks, from multiplex real-time PCR analysis, for Globodera pallida and G. rostochiensis were 83.3 and 88.7, respectively. The importance of DNA extraction, PCR and sequence analysis for the molecular identification of PCN is discussed. This study has significant implications for detecting species of PCN in order to monitor/develop control strategies for the PCN of quarantine importance.

Effects of Various Sewage Sludge Treatment Processes on the Survival of Potato Cyst-Nematodes (Globodera spp.) and the Implications for Disposal

1989 ◽  
Vol 21 (8-9) ◽  
pp. 909-916
Author(s):  
A. M. Spaull ◽  
D. M. McCormack ◽  
E. B. Pike
Keyword(s):  
Anaerobic Digestion ◽  
Potato Cyst Nematodes ◽  
Cyst Nematodes ◽  
Sludge Treatment ◽  
Treatment Processes ◽  
Sewage Sludge Treatment ◽  
Thermophilic Digestion ◽  
C 30 ◽  
Effluent Exposure ◽  
Potato Crops

Samples of sewage sludges, taken over a 12-month period from 9 Scottish sewage works, contained on average 0.24 cysts of Globodera spp. (potato cyst-nematodes) of which 11% were viable. The incidence was not significantly related to season or to the presence of vegetable-processing effluent. Exposure of cysts in sludge to mesophilic anaerobic digestion (35 °C, 30 min) cold anaerobic digestion (9 weeks), pasteurisation (70 °C, 30 min) and aerobic thermophilic digestion (60 °C, ld) reduced viability of eggs within the cysts by almost 100%. Sludges so treated can therefore be considered to be free from infection risk to potato crops, although the non-infective cysts may still be recovered. Treatment with lime at pH 11.5 (20 °C, 24 h), by aerobic stabilisation in an oxidation ditch (7 weeks) and by activated-sludge treatment (5d) did not reduced viability acceptably. Accelerated cold digestion did not reduce viability sufficiently after the usual 15 weeks but rendered eggs completely non-viable after 21 weeks. The results show that even sludge treated to destroy viable cysts should not be applied to land used for growing seed potatoes and subject to testing for freedom from infestation. Treatment destroying viability should increase the acceptability of sludge for ware potato growers, although the numbers of cysts applied in untreated sludge would be unlikely to increase significantly levels of cysts in soils already infested.

scholarly journals Taxonomy, Morphological and Molecular Identification of the Potato Cyst Nematodes, Globodera pallida and G. rostochiensis

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 184
Author(s):  
John Wainer ◽  
Quang Dinh
Keyword(s):  
Life Cycle ◽  
Molecular Identification ◽  
Soil Sampling ◽  
Globodera Pallida ◽  
Potato Cyst Nematodes ◽  
Cyst Nematodes ◽  
Primary Focus

The scope of this paper is limited to the taxonomy, detection, and reliable morphological and molecular identification of the potato cyst nematodes (PCN) Globodera pallida and G. rostochiensis. It describes the nomenclature, hosts, life cycle, pathotypes, and symptoms of the two species. It also provides detailed instructions for soil sampling and extraction of cysts from soil. The primary focus of the paper is the presentation of accurate and effective methods to identify the two principal PCN species.

scholarly journals Locomotion postural variability and coordination in boys with overweight

2021 ◽  
pp. 105971232110240
Author(s):  
Shahab Parvinpour ◽  
Marzie Balali ◽  
Mohsen Shafizadeh ◽  
Fatemeh Samimi Pazhuh ◽  
Michael Duncan ◽  
...  
Keyword(s):  
Body Mass ◽  
Movement Pattern ◽  
Approximate Entropy ◽  
Normal Weight ◽  
Multiscale Entropy ◽  
Body Movements ◽  
Straight Line ◽  
Straight Line Distance

The purpose of this study was to examine the variability and coordination of postural adaptations in normal weight children and those with overweight in running and hopping. Fifty-six boys between 7 and 10 years were classified into groups as overweight ( n = 33) or normal-weight ( n = 23). They performed two trials of running and hopping over a 20-m straight line distance. Accelerometers were attached on the trunk and head for collecting body movements in different directions from 15 strides. Postural variability and coordination were calculated by multiscale entropy and cross approximate entropy for the running and hopping trials, separately. Findings highlight overweight boys had significantly higher trunk-head coordination in mediolateral direction than normal-weight boys (0.72 vs. 0.68). The hopping movement pattern had highest variability (9.88 vs. 8.77) and trunk–head coordination (0.61 vs. 0.67) than running. Excess body mass demands additional postural adaptations to compensate for reducing the risk of losing balance laterally in boys with overweight.

Dispersal patterns in a regional koala population in south-east Queensland

2003 ◽  
Vol 30 (3) ◽  
pp. 281 ◽  
Author(s):  
David S. Dique ◽  
Jim Thompson ◽  
Harriet J. Preece ◽  
Deidré L. de Villiers ◽  
Frank N. Carrick
Keyword(s):  
Urban Areas ◽  
Home Ranges ◽  
Adult Males ◽  
Dispersal Patterns ◽  
Young Males ◽  
Straight Line ◽  
The Social ◽  
Straight Line Distance ◽  
Males And Females ◽  
Natal Home

Koala dispersal was investigated as part of a detailed ecological study of a nationally significant koala population located 20 km south-east of Brisbane, Queensland. From 1996 to 2000, 195 koalas from three sites were captured and fitted with radio-collars. A total of 40 koalas (23 males and 17 females) dispersed from these sites. Most (93%) dispersing individuals were 20–36 months of age. Three adult females (more than 36 months old) dispersed and no adult males dispersed during the study. A significantly higher proportion of young males dispersed than females. Dispersal occurred between June and December, with most dispersal of males commencing in July and August and that of females commencing between September and November prior to, and early in, the annual breeding season. The mean straight-line distance between the natal and breeding home ranges for males and females was similar and was measured at 3.5 km (range 1.1–9.7 km) and 3.4 km (range 0.3–10.6 km) respectively. Dispersing males and females tended to successfully disperse south and west of their natal home ranges and were generally unable to successfully disperse to urban areas within the study area, as a high proportion of the mortality of dispersing koalas was associated with attacks by domestic dogs and with collisions with vehicles on roads. Information from other studies indicates that most young koalas disperse from their natal areas. It is likely that the social behaviour and mating systems of koala populations provide mechanisms for young koalas to disperse. The potential role of dispersal in the dynamics of regional koala populations is discussed.

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