THE EPIDEMIOLOGY AND CONTROL OF NOSEMA DISEASE OF THE HONEY-BEE

The proportion of honey-bees infected with Nosema apis (Zander) declines in summer as the old infected bees die, for they cease to transmit their infection to the newly emerged individuals during the flying season. N. apis spores survive the summer on combs contaminated with infected faeces during the preceding winter. Although bees clean the combs during the summer, all infected material is not removed, and even well-used brood comb, which has been repeatedly cleaned by bees, can carry infection. Only a few bees may contract infection in the autumn from these faeces, but they join the winter cluster and initiate the next outbreak of the disease. Transferring a colony on to clean comb early in the spring or summer removes the source of the disease, and it then disappears when all the old infected bees die.
Old broodless comb can be sterilized quite simply by fumigation for a few days with the vapours of formalin or glacial acetic acid. Acetic acid is preferable, because it does not poison any honey or pollen in the combs. Formaldehyde can safely be used only with empty combs.
The autumn is the best time for treating colonies chemotherapeutically, because the combs are then cleanest and the few bees which are infected can be cured during the winter. The drug can be incorporated in the syrup normally fed to colonies in autumn, and there is no risk of seriously contaminating subsequent honey crops. However, such treatment cannot eliminate the disease because sufficient spores remain on the combs for the disease to start again when the drug supplied in the winter stores is exhausted.     

Summer Hot Snaps and Winter Conditions: Modelling White Syndrome Outbreaks on Great Barrier Reef Corals

Coral reefs are under increasing pressure in a changing climate, one such threat being more frequent and destructive outbreaks of coral diseases. Thermal stress from rising temperatures has been implicated as a causal factor in disease outbreaks observed on the Great Barrier Reef, Australia, and elsewhere in the world. Here, we examine seasonal effects of satellite-derived temperature on the abundance of coral diseases known as white syndromes on the Great Barrier Reef, considering both warm stress during summer and deviations from mean temperatures during the preceding winter. We found a high correlation (r² = 0.953) between summer warm thermal anomalies (Hot Snap) and disease abundance during outbreak events. Inclusion of thermal conditions during the preceding winter revealed that a significant reduction in disease outbreaks occurred following especially cold winters (Cold Snap), potentially related to a reduction in pathogen loading. Furthermore, mild winters (i.e., neither excessively cool nor warm) frequently preceded disease outbreaks. In contrast, disease outbreaks did not typically occur following warm winters, potentially because of increased disease resistance of the coral host. Understanding the balance between the effects of warm and cold winters on disease outbreak will be important in a warming climate. Combining the influence of winter and summer thermal effects resulted in an algorithm that yields both a Seasonal Outlook of disease risk at the conclusion of winter and near real-time monitoring of Outbreak Risk during summer. This satellite-derived system can provide coral reef managers with an assessment of risk three-to-six months in advance of the summer season that can then be refined using near-real-time summer observations. This system can enhance the capacity of managers to prepare for and respond to possible disease outbreaks and focus research efforts to increase understanding of environmental impacts on coral disease in this era of rapidly changing climate.     

Phenological characteristics of the tree layer of Kumaun Himalayan forests

The phenology of tree components of natural forests occurring between 350 and 2150 m in Kumaun Himalaya is descibed. All forests had more evergreen than deciduous taxa. The degree of evergreenness increased with increasing elevation and decreasing summer dryness. For most species (including all dominants) concentrated leafdrop and simultaneous leafing occurred during the warm-dry period of the year. About half of the species showed multiple leafing.All species had a sharp flowering peak in April. Wet-season flowering was rare. Most of the species flowered synchronously. In the sal- (Shorea robusta) and pine (Pinus roxburghii) forests a single peak of fruit maturation occurred in summer, while in other forests there also was a secondary peak in autumn.Nomenclature generally follows Osmaston (1926), the authority is given where the species is mentioned first.Financial support from the Department of Science and Technology, Government of India, is grategully acknowledged. We thank Dr. Y. P. S. Pangtey and Dr. J. C. Tewari for their help respectively in plant identification and ordination.     

A simulation model for an Iridaea splendens (Gigartinales,Rhodophyta) population in Vancouver,Canada

Populations of Iridaea splendens at Brockton Point, Stanley Park, Vancouver, Canada were observed to alternate in dominance between the gametophytic phase in summer and tetrasporophytic phase in winter. The mechanism regulating this alternation is not clear. Using a matrix projection model to simulate population growth, we show that this alternation is possible if there are differential survival and recruitment rates of the two phases in summer and winter. Sensitivity and elasticity analyses indicate the relative importance of perennation vs. recruitment. Recruitment from tetrasporophytes and from gametophytes both contribute about 25% to the population growth. Perennation among gametophytes is more important than among tetrasporophytes. The implication of this is that if this population is to be harvested, more tetrasporophytes can be harvested than gametophytes without resulting in the depletion of the resource. This is simulated in the matrix model by comparing the relative effects on population growth of increasing the mortality rate of the perennation phase of tetrasporophyte and gametophyte by 50 to 75%, and increasing recruitment rate in either phase, from summer to winter or from winter to summer.Dedicated to Dr T. Bisalputra of the University of British Columbia on the occasion of his retirement.     

The HLA system and its contribution to the genetics of rheumatic diseases

The results of the study of histocompatibility antigens at loci A, B and Dr in patients with RA and SLE, and their first degree relatives are presented. HLA antigens B12. B18, B27, Dr2 and Dr4 were associated with RA. The antigens HLA A11, B7, B35, Dr2 and Dr3 were associated with SLE. The influence of HLA antigens on formation of clinical picture of RA and SLE was determined. Evaluation of interallelic and interloci antigens interaction in a relative risk of disease suggests that, in some cases, there is a "superdominance" effect. Some combinations of HLA antigens at loci B and Dr increase the disease risk for RA and SLE. Analysis of test-marker linkage to genes predisposed to RA and SLE provides no direct confirmation of the hypothesis of their location on the short arm of the sixth chromosome between loci B and Dr, though this possibility cannot be completely excluded.     

Environmental signals implicated in Dr fimbriae release by pathogenic Escherichia coli

Afa/Dr diffusely adhering Escherichia coli have been shown to cause urinary tract infections and enteric infections. Virulence of Dr-positive IH11128 bacteria is associated with the presence of Dr fimbriae. In this report, we show for the first time that the Dr fimbriae are released in the extracellular medium in response to multiple environmental signals. Production and secretion of Dr fimbriae are clearly thermoregulated. A comparison of the amounts of secreted fimbriae showed that the secretion is drastically increased during anaerobic growth in minimal medium. The effect of anaerobiosis on secretion seemed to depend on both the growth phase and the culture medium. The secretion was maximal during the logarithmic-phase growth and corresponded to 27 and 57% of total Dr fimbriae produced by bacteria grown in mineral medium+glucose and LB broth, respectively. Thus, the anaerobic environment of the colon would favour the secretion of Dr fimbriae during bacterial multiplication. The controlled release of the Dr fimbriae, which is carried out in the absence of cellular lysis, appears independent of the action of proteases or a process of maturation. The mechanism employed in the liberation of Dr fimbriae thus seems different from that described for the adhesins FHA and Hap of Bordetella pertussis and Haemophilus influenzae.     

细叶满江红大孢子果的扫描电镜观察

细叶满江红(Azolla filicufoides Lam.)是优良的水生绿肥和饲料作物,又是用孢子果越夏和过冬的好材料,植物学者对其进行广泛研究已有悠久的历史。本文记述了电镜扫描观察到的大孢子果及小孢子囊泡胶块的图象;认为大孢子果表面同小孢子囊泡胶块的附着力,与大孢子果的萌发力有相关性;指出孢子果带菌,将是导致高温季节大田满江红发生毁灭性病害“自然倒萍”的主要因素之一。     

The discomfort index,mortality and the London summers of 1976 and 1978

The Discomfort Index (DI), and its associated heat load categories as worked out for conditions in Israel, was used in a study of the summer months of 1976 and 1978 in London. The cool summer of 1978 presented no heat load problems but the exceptionally warm summer of 1976, especially the period between 22 June and 9 July, produced several days of moderate heat load conditions. During this hot spell mortality from ischaemic heart disease, cerebrovascular accidents and respiratory disease all increased substantially. It is suggested that the heat load categories, although rarely attained, would be useful in predicting danger periods during heatwave conditions in the United Kingdom.     

Circannual Variations in Blood Cholesterol Levels

The seasonality of blood cholesterol is still not well established. Some have described a seasonal pattern with highest levels during autumn and lowest in summer, whereas others have reported no change. A number of studies showed circannual variations with maximum levels in winter and minimum in summer. The aim of this study was to examine the circannual variation of cholesterol in a large cohort in Israel. In the Israeli CORDIS study, employees of 21 factories were screened for cardiovascular disease risk factors during 1985-7. As part of the information gathered, serum cholesterol and blood counts were available for 3,726 men and 1,514 women. Serum cholesterol levels fit a circannual rhythm assessed by the cosinor analysis. Highest levels of serum cholesterol were found in spring and lowest in summer. We conclude that there is a circannual change of serum cholesterol, which could be partially associated with changes in environmental temperature. The circannual variation in serum cholesterol was considerable and should be taken into account when carrying out clinical evaluation of patients.     

Three Human Skeletons From The Pk Burial Sheridan County,Wyoming

Abstract

Fragmentary skeletal material from a burial found near the Big Horn Mountains of north-central Wyoming was determined to constitute the remains of three individuals. The few artifacts in association provide little basis for an assessment of cultural affiliation, however, cranial characteristics suggest a close relationship to previously studied Siouan populations.

In February, 1962 Mr. Donald C. Grey of Sheridan, Wyoming submitted skeletal material recovered from the PK Burial Site in Sheridan County, Wyoming to Dr. William M. Bass for identification. Assistance in the analysis of the material was given by Mr. Donald C. Lacy, a graduate studentinphysicalanthropology. According to Mr. Grey (personal communication February 14, 1962), the PK Burial Site was discovered during the summer of 19 59 by a University of Illinois geology student, a member of a summer field crew based at Sheridan College, Sheridan, Wyoming. He discovered a human skull (See Fig. 1: a, b, and c) exposed in the side of a small hilltop overlooking a rodeo corral on a ranch west of Sheridan. The site is located in the foothills of the Big Horn Mountains.     

Experimental oral polio vaccines and acquired immune deficiency syndrome

The simian immunodeficiency virus (SIV) of the common chimpanzee is widely acknowledged as the direct ancestor of HIV-1. There is increasing historical evidence that during the late 1950s, kidneys were routinely excised from central African chimpanzees by scientists who were collaborating with the polio vaccine research of Dr Hilary Koprowski, and sent - inter alia - to vaccine-making laboratories in the USA and Africa, and to unspecified destinations in Belgium. While there is no direct evidence that cells from these kidneys were used as a substrate for growing Dr Koprowski's oral polio vaccines, there is a startling coincidence between places in Africa where his CHAT vaccine was fed, and the first appearances in the world of HIV-1 group M and group-M-related AIDS. Because of the enormous implications of the hypothesis that AIDS may be an unintended iatrogenic (physician-caused) disease, it is almost inevitable that this theory will engender heated opposition from many of those in the scientific establishment, and those with vested interests.     

Some aspects of the ecology of the desert snail Sphincterochila prophetarum in relation to energy and water flow

Summary Between 1976–1978, we studied the ecology of the Sphincterochila prophetarum, the most common snail, on stony slopes in Northern Negev. Energy and water flow determinations were made at the individual and population levels on a field observation basis and metabolic data were derived from laboratory simulations.The snails are active during 5–7% of the time during the year, while the remaining 95% of the time, the snails are in aestivation under stones. The energy and water inputs during the short feeding periods are very fast. Only 8% of the total energy in the eaten food are assimilated. Eighty-nine percent of the total assimilated energy are utilized in respiration during the various periods of activity and dormancy.The water loss during the feeding and activity period is about 37% of the total annual input. The snails lose twice as much the amount of water during the winter dormancy periods than in the summer dormancy period.Dedicated to Prof. Evenari and Dr. Springer     

Annual variation in lymphocystis infection frequency in flounder, Platichthys flesus (L.)

The infection frequency of the virus induced lymphocystis disease has been registered in flounder from the Oslofjord, Norway, during a 4 year period. The disease has a clear regular seasonal variation, and also an annual variation. The percentage infection in the summer was 1–10%, and in the winter up to 57%. The possibility that the high pollution level of the inner Oslofjord could be the reason for the high frequency of lymphocystis disease, is discussed.     

Pulsed-field gel electrophoresis profiles of aeromonads isolated from healthy and diseased Helix aspersa from French snail farms

The XbaI digestion patterns of chromosomal DNA of 42 aeromonads isolated from French breeding snails during a new epizootic disease, which rapidly progressed to death during the summer of 1994, were analyzed by pulsed-field gel electrophoresis. Biochemical identification to species level was also performed. Interestingly, we found that 76% of the aeromonads isolated from diseased snails clustered into a unique pulsotype (P1) whatever their geographic origin, and were assessed to belong to Aeromonas hydrophila. Other strains belonged to Aeromonas caviae or remained unspecified. Our results provide retrospective supplementary epidemiological evidence for implication of A. hydrophila strains in the snail summer disease.     

Tracking climate impacts on the migratory monarch butterfly

Understanding the impacts of climate on migratory species is complicated by the fact that these species travel through several climates that may be changing in diverse ways throughout their complete migratory cycle. Most studies are not designed to tease out the direct and indirect effects of climate at various stages along the migration route. We assess the impacts of spring and summer climate conditions on breeding monarch butterflies, a species that completes its annual migration cycle over several generations. No single, broad‐scale climate metric can explain summer breeding phenology or the substantial year‐to‐year fluctuations observed in population abundances. As such, we built a Poisson regression model to help explain annual arrival times and abundances in the Midwestern United States. We incorporated the climate conditions experienced both during a spring migration/breeding phase in Texas as well as during subsequent arrival and breeding during the main recruitment period in Ohio. Using data from a state‐wide butterfly monitoring network in Ohio, our results suggest that climate acts in conflicting ways during the spring and summer seasons. High spring precipitation in Texas is associated with the largest annual population growth in Ohio and the earliest arrival to the summer breeding ground, as are intermediate spring temperatures in Texas. On the other hand, the timing of monarch arrivals to the summer breeding grounds is not affected by climate conditions within Ohio. Once in Ohio for summer breeding, precipitation has minimal impacts on overall abundances, whereas warmer summer temperatures are generally associated with the highest expected abundances, yet this effect is mitigated by the average seasonal temperature of each location in that the warmest sites receive no benefit of above average summer temperatures. Our results highlight the complex relationship between climate and performance for a migrating species and suggest that attempts to understand how monarchs will be affected by future climate conditions will be challenging.     

The role of phenolic compounds in disease resistance in geranium

The present study was conducted in the hill station of G B Pant University of Agriculture and Technology, Ranichauri, Uttarakhand, which is known for its diversity in medicinal and aromatic plants. The plant geranium, also known as rose or lemon geranium is highly valued for its essential oil which is used in the cosmetic and preferring industries. The plant suffers due to stem and root rot both during summer and winter seasons. In the present study, geranium plants showed maximum stem rot incidence (60.55%) and plant mortality (17.20%) during the winter season, whereas in summer the crops showed maximum root rot and wilt complex incidence (38.33%) with plant mortality up to (12.22%). The average stem rot mortality was comparatively low (16–20%) in summer but increased to 18–26% in winter crop. Several phenolic acids such as as tannic, gallic, caffeic, ferulic and benzoic were detected by using high performance liquid chromatography (HPLC) in variable amounts in these plants. The disease intensity varied from 97.77 to 92.46% from season to season. The significance of the phenolic compounds is discussed in relation to disease prevalence.     

Distribution and ecology of campylobacters in coastal plain streams (Georgia, United States of America)

Campylobacter is the leading cause of bacterium-associated diarrhea in the United States and most developed countries. While this disease is considered a food-borne disease, many clinical cases cannot be linked to a food source. In rural and agrarian areas environmental transmission may be an important factor contributing to case loads. Here we investigated the waterborne prevalence of campylobacters in a mixed-use rural watershed in the coastal plain of southern Georgia (United States). Six sites representing various degrees of agricultural and human influence were surveyed biweekly to monthly for 1 year for the presence of culturable thermophilic campylobacters and other measures of water quality. Campylobacters were frequently present in agriculture- and sewage-impacted stretches of streams. The mean campylobacter counts and overall prevalence were highest downstream from a wastewater treatment plant that handled both human and poultry slaughterhouse waste (相似文献   

The impact of rising temperatures on the prevalence of coral diseases and its predictability: A global meta-analysis

Coral reefs are under threat from disease as climate change alters environmental conditions. Rising temperatures exacerbate coral disease, but this relationship is likely complex as other factors also influence coral disease prevalence. To better understand this relationship, we meta-analytically examined 108 studies for changes in global coral disease over time alongside temperature, expressed using average summer sea surface temperature (SST) and cumulative heat stress as weekly sea surface temperature anomalies (WSSTAs). We found that both rising average summer SST and WSSTA were associated with global increases in the mean and variability in coral disease prevalence. Global coral disease prevalence tripled, reaching 9.92% in the 25 years examined, and the effect of ‘year’ became more stable (i.e. prevalence has lower variance over time), contrasting the effects of the two temperature stressors. Regional patterns diverged over time and differed in response to average summer SST. Our model predicted that, under the same trajectory, 76.8% of corals would be diseased globally by 2100, even assuming moderate average summer SST and WSSTA. These results highlight the need for urgent action to mitigate coral disease. Mitigating the impact of rising ocean temperatures on coral disease is a complex challenge requiring global discussion and further study.