bluuebunny/crossref_metadata_2025_split huggingface dataset:
Productivity of Glossina austeni Newst. maintained on lop-eared rabbits
Authors: Jordan A. M. , Curtis C. F. 
Published: July 2009

A life-table and age-specific fecundity schedule are given for females of Glossina austeni Newst. maintained on lop-eared rabbits. From these the innate capacity for increase in numbers (τm) is calculated, from two sets of data, as 0.0166 and 0.0155 per day, respectively. These values are better than previously obtained for Glossina and it is concluded that as such they were mainly due to the excellent nutrition of the flies. A colony in which all female offspring produced are added to the breeding stock is referred to as being in the ‘expanding phase’. The stable age distribution that would be established in a rabbit-fed colony of G. austeni in the expanding phase and the expected rate of increase in numbers of the colony when the stable age distribution exists are calculated from the value of τm.The characteristics of a colony of G. austeni in the ‘stationary phase’, when only those offspring required to maintain the colony at a constant size are retained, are described. It is concludef that a stationary colony of y adult flies would have a disposable output per week of 0.277y young adult males and 0.233y young adult females. Some implications of these findings in relation to the sterible male techinque for tsetse control are briefly discussed.
Activity Cycles ofGlossina pallidipesAust.,G. palpalis fuscipesNewst. andG. brevipalpisNewst
Authors: Harley J. M. B. 
Published: July 2009

A series of 24-hr catches ofGlossina pallidipesAust.,G. palpalis fuscipesNewst. andG. brevipalpisNewst. was carried out on the north-east shore of Lake Victoria over a period of 11 months in 1962–63. The object was to define and compare the daily pattern of activity of the three species as indicated by the numbers caught hourly on three black cattle that were used as bait. Catching during the hours of darkness was done by the light of dimmed hurricane lamps. The period of observation covered successively a dry season, a wet season, a cool dry season and a hot dry season.At all seasons, males ofG. pallidipeswere caught in gradually increasing numbers from just before dawn until shortly before sunset, after which a rapid decrease took place. Females ofG. pallidipesexhibited a different pattern, with a gradual rise in activity in the morning until about midday, after which activity remained more or less constant until shortly before sunset, when a rapid fall occurred. There was never any indication of a morning peak in activity such as has been described for this species elsewhere. Activity during the night was at an extremely low level.Activity of both males and females ofG. p. fuscipesstarted about dawn, increased to a peak in the middle hours of the day, and then fell fairly rapidly in the evening; the exact time of the peak was variable. None was caught during the night.There was some activity ofG. brevipalpisthroughout the diel, but marked peaks of activity were exhibited by both sexes. In the open, these took place immediately after sunset and immediately before sunrise, the latter being the smaller. In the shade, the morning peak in both sexes was an hour later than in the open, and the evening peak in males alone was an hour earlier.These results are compared with those of other workers, and the influence of physical factors is discussed. Particular values of temperature and saturation deficit were not closely associated with particular levels of activity of any of the three species, and light intensity is probably the physical factor that is most consistently the same at times of particular levels of activity at all seasons.
Effect of gamma-radiation on the tsetse fly Glossina Morsitans Westw
Authors: Dean G. J. , Wortham S. M. 
Published: July 2009

Puparia of Glossina morsitans Westw. were collected in the Zambesi valley and contained developmental stages from final phases of third-instar larvae to pupae near to eclosion. These puparia or the emerging adults were exposed to gamma-radiation from a Co60 source at rates between 54 and 122 rad/min. Effective mortality in the pupal stage increased from 23 per cent, at 2,000 rads to 64 per cent, at 15,000 rads, while those deposited in spring (August-October) were more sensitive to gamma-rays than those collected in winter (May-July).Under described test conditions, 25 pairs of untreated flies produced a mean of 21 pupae in a 28-day test period, insemination averaged 95 per cent., and 56 and 62 per cent, of the males and females survived, respectively. Continuous irradiation reduced reproduction by over 95 per cent, between 8,000 and 15,000 rads wiih males emerging within the first two weeks after treatment; while males emerging during the third post-treatment week were completely sterilised with dosages above 4,000 rads. Treatments given as fractions one and four days apart gave a slightly higher level of residual fertility than that obtained with similar but continuous total dosages. Irradiation of adult males reduced reproduction to an extent comparable with that observed in males emerging from pupae within two weeks of treatment (> 90 per cent, from 8,000 rads). Females treated either as adults or as pupae were completely sterilised with doses of 1,000 to 8,000 rads. Males exposed to 8,000 and 12,000 rads retained their sterility throughout 39- and 45-day test periods, and were fully competitive with untreated males.Survival of virgin flies emerging from treated pupae was reduced both by increasing dosage from 4,000 to 15,000 rads, and decreasing pupal age at the time of treatment. Mortality during the 28-day mating period decreased with 1,000 and 2,000 rads, increased up to 8,000 rads, and apparently decreased with 12,000 and 15,000 rads. When the doses were fractionated, survival was longer than when treatment was continuous, and mortality was reduced to the level expected from the size of the first fraction. Virgin adult males given doses between 4,000 and 18,000 rads, and females given 2,000 and 4,000 rads, lived longer than the corresponding controls.The ability of the males to inseminate females was not affected by any of the treatments, and sperm from irradiated males were mobile and apparently behaved normally. Dominant lethality in the males was expressed by the failure to produce pupae in matings with untreated females, and in the treated female fly by the complete failure of oogenesis.
Interplant movement of apterous aphids with special reference to Myzus persicae (Sulz.) (Hem., Aphididae)
Authors: Ferrar P. 
Published: July 2009

It is likely that under some conditions apterous aphids are significantly involved in the spread of plant viruses, most importantly by walking across soil from plant to plant. Various factors which affect their importance are considered in the paper.Figures are given for the frequency of movement of apterae of Myzus persicae (Sulz.) under settled conditions; this was found to vary with the species of host-plant that the aphid was on.Eourth-instar and adult apterae can walk proficiently on soil. The effect of soil condition on this is described. The walking speed of adult apterae on soil is 5.2 cm./min. at 18°C, and 1.2 cm./min. at 8.5°C. The walking speed of fourth-instar aphids on soil is 3.2 cm./min. at 18°C.Experiments showed that walking aphids are well able to locate a new host-plant, and that the attraction is visual.The significance of these observations is discussed, and it is concluded that apterae have a greater potential as virus vectors than has been generally realised.
The effect of temperature, humidity and quantity of food on the development and diapause of Trogoderma parabile Beal.
Authors: Burges H. D. 
Published: July 2009

The rate of development and the egg-production of the Dermestid beetle, Trogoderma parabile Beal, at 30°C. and 60 to 70 per cent. R.H. and the effect upon larval development of the volume of food, the temperature and the relative humidity have been determined.In 15 to 450 cc. of wheatfeed at 30°C. and 60 to 70 per cent. E.H., active adults are formed from eggs in a mean of 39 days (egg 6, larva 26, pupa 5 and pre-emergence 2). Males develop slightly more rapidly than females. On average, a female adult lives 8 days and 53 of her offspring reach maturity. The weekly rate of increase of a population of stable age distribution (A) is × l·7.At temperatures between 17·5 and 37·5°C. (and at 70 per cent. R.H.) and at humidities between near 0 and 90 per cent. R.H. (and 30°C.) larvae can grow to a large size; but in 0·7 to 25 cc. of food some of these large larvae enter a facultative diapause, as a result of restricted space. Disturbance of the food increases the proportion of diapause larvae. The diapause larvae feed and moult intermittently. At 30°C. and 60–70 per cent. R.H., a period of seven weeks after hatching has been adopted arbitrarily to distinguish diapause and non-diapause larvae. Only a limited success was obtained in breaking the diapause, which is less readily broken than that of T. granarium Everts.
Seasonal variations in the fat content and size of Glossina swynnertoni Austen.
Authors: Glasgow J. P. , Bursell E. 
Published: July 2009

A population of Glossina swynnertoni Aust., at Shinyanga, Tanganyika, has been studied in respect of size and fat content of non-teneral males by monthly samples over a period of 13 years.Flies are large from February to July and small from August to January, and this change in size suggests an effect of the wet season (December to May) and dry season (June to November) upon the parent females, allowing for the time-lag of two months representing pupal development and mean age of adult males at capture. Male flies have more fat in the rains and less in the dry season and it is possible that similar changes in the nutritional status of females are responsible for the observed size changes.The correlation found in earlier work between the size of male flies in any month and saturation deficit two months earlier is confirmed, but reasons are given for rejecting a simple causal interpretation of this correlation.Since 1951, there has been a progressive decrease in size of G. swynnertoni in the area studied, more especially as regards those produced in the dry season.
Rearing Pseudotheraptus wayi Brown (Coreidae) a pest of coconuts in East Africa, and evaluation of its susceptibility to various insecticides.
Authors: Wheatley P. E. 
Published: July 2009

A method is described for the large-scale rearing of Pseudotheraptus wayi Brown, the Coreid causing immature nutfall of coconuts in East Africa.Adults were kept in cages with sides of thick white drill and wire-gauze, in an outdoor insectary at Matuga, near Mombasa, Kenya, and were provided with freshly collected fallen nutlets from which the bracts had been removed. Eggs were normally laid on the walls of the cage. The nutlets were replaced every two days, and all newly hatched nymphs removed and placed in other cages supplied with fresh nutlets every second day. There was some mortality in the first- and second-instar nymphs due to the handling entailed when nutlets were replaced, but in the later nymphal stages it was very low. Under these rearing conditions, the life-cycle from egg to adult was completed in from 35 to 40 days.The toxicities to Pseudotheraptus of dieldrin, DDT, γ BHC, malathion and pyrethrins in a solvent were compared by topical application of measured-drop doses from an Agla micrometer syringe in a range of five concentrations (except for DDT, where eight concentrations were used). The mortality counts at 72 hr. were taken as the measure of toxicity.Analysis of the log dosage/probit regression lines indicated that dieldrin was markedly more toxic than DDT to Pseudotheraptus, and that the toxicity to this insect of pyrethrins was of a very low order.In a supplementary experiment to determine whether the addition of resin improved the toxicity of DDT when applied topically, batches of adults were treated with measured drops of a solution of p, p'DDT (0·5 per cent, for females, 0·25 per cent, for males) and others with the same concentrations of DDT to which coumarone indene resin at one-tenth of the DDT content had been added. The toxicity of the DDT was not enhanced.
The Growth-Changes and Structure of the Egg of the African Migratory Locust,Locusta migratoria migratorioides, R. & F. (Orthoptera, Acrididae)
Authors: Roonwal Mithan Lal 
Published: July 2009

The eggs ofLocusta migratoria migratorioides, R. & F., increase in size during development. The increase is due to the absorption of water from the surrounding moist soil.The wet weight of a freshly laid egg is 0·0063±0·0008 gms, and of a fully developed egg 0·014±0·002 gms. The dry weight of a freshly laid egg is 0·003± 0·0004 gms. and of a fully developed egg 0·0024±0·0002 gms. The water-content of an egg increases from 51·92±3·53 per cent, of the wet weight in the freshly laid egg to 82·36±2·14 per cent, in the fully developed egg.The egg-wall consists of an exo- and endochorion and a thick vitelline membrane. The latter has a felt-like structure in the freshly laid egg, but as the egg develops, this membrane increases in thickness and acquires a laminated character.The micropylar apparatus consists of a ring of about 35–43 oblique, funnelshaped canals arranged round the egg near its posterior end.
The Food-cycle of Dysdercus fasciatus in Acacia Savannah in Northern Rhodesia
Authors: Bebbington A. G. , Allan W. 
Published: July 2009

A study of the variations of the population of Dysdercus fasciatus on cotton and on its wild host-plants is described.The most important host of D. fasciatus in the Acacia savannah of Northern Rhodesia is Thespesia rogersii, and it is shown that at certain times a general flighting of stainer takes place from this host-plant caused by food shortage or defoliation. Generally a period of food shortage occurs during the earlier months of the year owing to rotting of the old crop and extensive destruction of the early new crop by the larvae of a Cossid moth. This causes an early influx into cotton, which leads to the establishment of a large population in the field at a critical period in the development of the bolls. When the early crop is retained on the trees a continuously increasing food supply is provided, and this first movement does not take place. A second movement from Thespesia, which is largely due to defoliation, begins generally in June. It has been shown that a second influx into cotton coincides with this later movement from Thespesia. A late influx such as this is of little practical importance since the greater part of the crop is picked in May and June.The observations recorded indicate clearly that the movement of D. fasciatus into cotton is not due to any attraction exercised by the crop but is caused by a forced movement of stainers from Thespesia rogersii.
Predictors of survival after aortic valve replacement in patients with low‐flow and high‐gradient aortic stenosis
Authors: Ding Wen‐Hong , Lam Yat‐Yin , Duncan Alison , Li Wei , Lim Eric , Kaya Mehmet G. , Chung Robin , Pepper John R. , Henein Michael Y. 
Published: July 2009

AimsTo identify predictors of survival following aortic valve replacement (AVR) in patients with low‐flow and high‐gradient aortic stenosis (AS).Methods and resultsEighty‐six patients (aged 71 ± 10 years) with severe AS [aortic valve mean pressure gradient >40 mmHg or valve area <1.0 cm2] and left ventricular (LV) dysfunction [ejection fraction (EF) <50%] underwent AVR. Cox proportional hazards were used to identify independent clinical and echocardiographic predictors of mortality. Operative (30‐day) mortality was 10%. Peri‐operative mortality was associated with lower mean LVEF, higher mitral E:A ratio, peak systolic pulmonary artery pressure (PSPAP), and serum creatinine (by 12%, 2.3, 28 mmHg, and 74 mmol/L, respectively, all P < 0.001), NYHA class III–IV (100 vs. 65%), concomitant CABG (89 vs. 55%), urgent surgery (78 vs. 35%), and longer bypass‐time (by 28 min, all P < 0.05). Mortality at 4 years was 17%. Univariate predictors [hazard ratio (HR)] of 4‐year mortality were: lower EF (HR 0.68 per % increase, P < 0.001), presence of restrictive LV filling (HR: 3.52, P < 0.001), raised PSPAP (HR: 1.07, P < 0.001), and CABG (HR: 4.93, P = 0.037). However, only low EF (<40%, HR 0.74, P = 0.030), the presence of restrictive filling (HR 1.77, P = 0.033), and raised PSPAP (>45 mmHg, HR 2.71, P = 0.010) remained as independent predictors after multivariate analysis.ConclusionThe severity of pre‐operative systolic and diastolic LV dysfunction is the major predictor of mortality following AVR for low‐flow and high‐gradient AS.
Spring Dead Spot of Bermudagrass: A Challenge for Researchers and Turfgrass Managers
Authors: Tredway Lane P. , Tomaso-Peterson Maria , Perry Hunter , Walker Nathan R. 
Published: July 2009

Spring dead spot is a destructive disease of bermudagrass turf in climates where the host is exposed to freezing temperatures during winter dormancy. The disease is the result of a complex interaction between a dormant host plant, fungal pathogens in the genus Ophiosphaerella, and environmental conditions. Although progress has been made in our understanding of the individual factors that determine spring dead spot development, we must begin to understand how factors interact to influence the disease. This knowledge will facilitate the development of effective and integrated management plans for spring dead spot in bermudagrass turf. Accepted for publication 8 May 2009. Published 10 July 2009.
Adult versus adolescent onset of smoking: how are mood disorders and other risk factors involved?
Authors: Ajdacic‐Gross Vladeta , Landolt Karin , Angst Jules , Gamma Alex , Merikangas Kathleen R. , Gutzwiller Felix , Rössler Wulf 
Published: July 2009

ABSTRACTAims  To examine the strength of association between smoking and mood disorders and the association between smoking and its traditional risk factors, comparing those who started smoking in adolescence with those who started smoking in early adulthood.Design and participants  The analyses relied on prospective data from the Zurich Study. This longitudinal community study started in 1979 with a stratified sample of 591 participants aged 20/21 years, weighted towards those with mental disorders. Follow‐up interviews were conducted at ages 23, 28, 30, 35 and 41.Measurements  In this analysis the adult versus adolescent onset of smoking was regressed on the cumulative prevalence of mood disorders, personality characteristics measured by the Freiburg Personality Inventory, common risk factors such as parental smoking, conduct and school problems, troubles with the family and basic socio‐demographic variables (sex, education).Findings  In the Zurich Study cohort we found that 61.6% were former or current smokers, of whom 87% started smoking before the age of 20 and 13% after the age of 20. Adolescent onset of smoking was associated strongly with later major depression, dysthymia or bipolar disorders and, furthermore, with parental smoking, extroverted personality and discipline problems and rebelliousness in youth. However, only depression and dysthymia were associated with adult onset smoking and other risk factors associated with smoking were not so associated in this group.Conclusions  Correlates of smoking onset in adolescence are mainly not applicable to the onset of smoking in young adulthood. Smoking onset beyond adolescence is an open research issue.
General scaling rules of the hysteretic water retention function based on Mualem’s domain theory
Authors: Mualem Y. , Beriozkin A. 
Published: July 2009

SummaryBased on the domain theory of hysteresis, the present study rigorously derives a unified scaling transformation for predicting the wetting scanning retention function, θw(ψ), following any sequence of wetting and drying processes, from the measured main wetting curve. It is proved theoretically that a shape‐similarity exists among the different wetting curves of a given soil. Each wetting scanning curve and the main wetting curve are described by the same normalized equation, over the common interval of ψ values. This shape‐similarity is a direct result of the Mualem domain theory. On this basis, a general unique equation is formulated for prediction of all wetting scanning curves, of all orders, which is compatible with the Mualem dependent, as well as independent, domain theory. On the same theoretical basis, it is proved that no similarity exists among the drying scanning curves. Thus, the use of the scaling transformation for prediction of the drying scans is subjected to inconsistency with the physical principles underlying the dependent domain theory. As a result, scaling in this case would inevitably lead to inaccuracies in the calculated drying curves. A significant step forward has been made in the present study, from Mualem’s dependent domain model (1984) with its implicit predictive formulae of the drying scanning curves. A unique explicit equation was theoretically derived, applicable for describing the drying scanning curves of all orders. This unique equation of the drying scanning curves, together with the general single equation of the wetting scanning curves, provided closure of all theoretical wetting and drying scans within the main hysteresis loop. Consequently, the retention function following any sequence of successive wetting and drying processes can be predicted by these two equations determined by the measured boundary curves.
Accumulation and solubility of metals during leaf litter decomposition in non‐polluted and polluted soil
Authors: Scheid S. , Günthardt‐Goerg M. S. , Schulin R. , Nowack B. 
Published: July 2009

SummaryThe decomposition of alder (Alnus glutinosa) and poplar (Populus tremula) leaf litter placed in direct contact with non‐polluted and metal‐polluted soil was investigated over 25 months in a controlled model‐ecosystem experiment using the litterbag method. In addition to mass loss, we monitored the total and soluble concentrations of carbon, Cu, Zn, Cd and Pb. Leaves from trees grown on polluted soil had larger initial Zn, Cd and dissolved organic carbon concentrations. Neither the origin of the leaves (from trees grown on non‐polluted or polluted soil) nor the placement of the leaves in polluted or unpolluted soil affected the decomposition process. Total metal contents increased in leaves placed on polluted soil over time. The solubility of metals in the leaf litter decreased over time, indicating that leaves acted as a temporary pool for metals from the soil in direct contact with the leaves. The sorbed metals were strongly bound in the litter even after two years of decomposition. The strong binding and thus reduced bioavailability of the metals provides an explanation for why they had no observable effects on litter decomposition.