The relationship between outbreaks, rainfall and low density populations of the African armyworm, Spodoptera exempta, in Kenya

2001 ◽  
Vol 98 (3) ◽  
pp. 285-294 ◽  
Author(s):  
Charles F. Dewhurst ◽  
William W. Page ◽  
Derek J.W. Rose

Mass emergences of moths from conspicuous gregarious-phase caterpillars in high densities are important sources of migrant moths, which are borne downwind to cause a progression of armyworm outbreaks northwards from Tanzania to Ethiopia, and southwards from Rhodesia to South Africa. This progression might possibly be checked by destroying outbreak caterpillars. The sources of moths which cause the first outbreaks before the progression starts are not known, and the possibility is examined that these come from scattered populations of solitary-phase caterpillars hidden at the bases of green grasses, where they are sometimes found at considerable density. Recent analyses of weather patterns on the estimated dates of arrival of the moths responsible for fourteen groups of outbreaks in Rhodesia suggest that outbreaks could often be caused by convergent windflow concentratin glow-density moth populations from sources between Rhodesia and the Mozambique coast, and that these sources may persist for several months. A model is presented which attempts to relate the phase forms found in the field with the life system of the armyworm .


2013 ◽  
Vol 98 (8) ◽  
pp. 3280-3287 ◽  
Author(s):  
Yasuyo Nakajima ◽  
Masanobu Yamada ◽  
Masako Akuzawa ◽  
Sumiyasu Ishii ◽  
Yasuhiro Masamura ◽  
...  

Context: Subclinical hypothyroidism (SCH) and metabolic syndrome (MetS) increase with age; however, their relationship remains unclear. Objective: Our objective was to investigate the relationship between SCH and indices of metabolic syndrome and follow up subjects for 1 year. Design: Cross-sectional and longitudinal follow-up studies of cases were collected from Takasaki Hidaka Hospital between 2003 and 2007. Participants: Overall, 11 498 participants of health checkups were analyzed. The mean age was 48 ± 9 years. Main Outcome Measures: The relationship between SCH and indices of MetS were examined. Results: Serum free T4 levels were lower in women than men in most of the age groups, and the prevalence of SCH, 6.3% in women vs 3.4% in men, increased with age, reaching 14.6% in 70-year-old women. Multivariate logistic-regression analyses revealed that waist circumference and the serum triglyceride and low-density lipoprotein-cholesterol levels were significantly higher in subjects with SCH than without among women. Reflecting these findings, the adjusted odds ratio of MetS in patients with SCH was higher than in the euthyroid subjects in women with an odds ratio of 2.7 (95% confidence interval 1.1–5.6; P = .017) but not in men. Furthermore, progression from euthyroid into SCH resulted in a significant increase in the serum triglyceride levels but not low-density lipoprotein-cholesterol in women. Conclusion: Japanese women exhibited a high prevalence of SCH associated with low free T4 levels. There was a strong association between SCH and several indices of metabolic syndrome in women. SCH may affect serum triglyceride levels and be a risk factor for metabolic syndrome.


2017 ◽  
Vol 50 (1) ◽  
pp. 36-57 ◽  
Author(s):  
Nurul Hidayah ◽  
Mariatti Mustapha ◽  
Hanafi Ismail ◽  
Mohamad Kamarol

This study determines the applicability of nanofillers (silica, boron nitride, and zinc oxide) in linear low-density polyethylene (LLDPE)/silicone rubber (SR) insulation compounds. Design of experiment is adopted to model the relationship between the properties (permittivity, loss tangent, dielectric strength, and volume resistivity) and factors (SR content, type of nanofiller, and nanofiller loading) for performance optimization. It is observed that SR content and type of nanofiller significantly influence the electrical properties of LLDPE/SR nanocomposites. Nanofiller loading, however, causes a small variation in the properties of the nanocomposites except for dielectric strength. From the optimization, it is found that the optimum formulation composition is 10 wt% of SR and 2 vol% of nanoboron nitride.


1995 ◽  
Vol 380 ◽  
Author(s):  
Alfred P. Weber ◽  
James D. Thorne ◽  
Sheldon K. Friedlander

ABSTRACTThe microstructure of an agglomerate can be characterized by the coordination number. The relationship between the fractal dimension and the coordination number of agglomerates of nanometer particles was investigated in experiments and computer simulations. The results for silver agglomerates formed by laser ablation agreed well with the simulations. The coordination number is low for low density fractals because of the large fraction of surface particles which have fewer bonds. The sensitivity of the coordination number to the fractal dimension increases with increasing fractal dimension.


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