Temporal changes in the level of infestation of Simulium ornatum Meigen (complex) (Simuliidae: Diptera) larvae by the endosymbiotic fungus Harpella melusinae Lichtwardt (Harpellales: Trichomycetes)

The fungus Harpella melusinae (Harpellales: Trichomycetes) is obligately associated with the midguts of larval Simuliidae (Diptera). The level of infestation of a population of Simulium ornatum by H. melusinae was monitored at a stream in Hampshire, England. Significant temporal changes in the level of infestation were recorded during monthly and weekly collections; a twenty-fold increase being recorded over a nine-day period. Possible mechanisms by which these changes occur are discussed.     

Calcium influences the stability and conformation of rotavirus SAH glycoprotein VP7 expressed in Dictyostelium discoideum

We have previously reported expression of the rotavirus outer capsid glycoprotein, VP7, in the relatively new expression host, Dictyostelium discoideum. To optimise yields of recombinant VP7, we examined the role of Ca²⁺ since stability of both VP7 and mature rotavirus during a rotavirus infection are calcium-dependent. Low micromolar levels of free extracellular Ca²⁺ were required to maximise yields of VP7 in D. discoideum whilst levels of VP7 were reduced following depletion of intracellular Ca²⁺ reserves using A23187 and EGTA. Immunoblot analysis suggested that VP7 was being degraded in an intracellular compartment. Immunoprecipitation with a conformation-dependent neutralising antibody confirmed that EGTA-induced Ca²⁺ chelation alters the conformation of VP7. These results suggest that stability of VP7 is dependent on maintaining adequate levels of intracellular Ca²⁺ and that conformational changes in VP7 which occur following depletion of Ca²⁺ reserves induce rapid proteolysis of the protein. Since these results establish conditions for expressing optimal levels of VP7 in the correct conformation they have important implications for the development of a subunit vaccine based on recombinant VP7.     

Behavioral and hormonal aspects of reproduction in captive goeldi’s monkeys (Callimico goeldii) in a comparative and evolutionary context

The fate of most nonhuman primate species is intimately related to man. The increasing encroachment on the natural habitat has resulted in the decimation and even near extinction of some species. Along with this development, the basic concept in many modern zoos has changed from one of merely display to self-perpetuating units. Primate research facilities are orienting their research programs towards reproductive physiology and behavior in an effort to provide basic knowledge of reproduction in these species. This increased emphasis in the area of reproductive biology and the various efforts to improve breeding of these mostly endangered primates in captivity has stimulated the author to write this review. It represents an attempt to provide the reader with basic background information relating to the endocrinology and behavior of reproduction in the clawed New World monkeys as it exists at the time of publication. The intermediate evolutionary position ofCallimico goeldii between the clawed New World monkeys and the ‘true New World monkeys’ and our relatively poor knowledge about reproduction and behavior in this particular species fully justifies the focus on Goeldi’s monkey in this essay. This review is an attempt to provide a brief history of previous studies but also the basis for research in the future. The current status of knowledge of the small-bodied clawed monkeys is also discussed in an evolutionary context, with an emphasis on the different reproductive strategies in this dynamic group of primates. The outcome, not surprisingly, confirms the unique position ofCallimico goeldii in its social, ecological, and evolutionary environment.     

Behavioural and chemosensory responses of the turnip root fly (Delia floralis) to glucosinolates

This study investigates the behavioural and neural mechanisms involved in the oviposition behaviour of the turnip root fly,Delia floralis (Fallen). Behavioural studies showed that glucosinolates modulated the oviposition behaviour of the flies on artificial leaves as well as the number of eggs laid in the soil at the base of these leaves. Electrophysiological responses to glucosinolates were obtained from type A and type D sensilla on the prothoracic and mesothoracic tarsi, as well as from the long contact sensilla on the labellum. The neural responses from these sensilla were positively correlated with the oviposition behaviour of the flies and with the number of eggs laid. Of the eleven glucosinolates tested in the behavioural and electrophysiological tests, the flies were most responsive to glucobrassicanapin, gluconapin and glucobrassicin. The type D tarsal sensilla were more responsive to the glucosinolates than either the type A tarsal sensilla or the labellar sensilla. The structure-activity investigations showed that slight modifications to the chemical composition of the glucosinolates resulted in changes in neural activity.     

Effects of promoter,intron and enhancer elements on transient gene expression in sugar-cane and carrot protoplasts

Various chimaeric promoter regions coupled to the uidA -glucuronidase gene were evaluated for transient expression strength following electroporation into sugar-cane (monocot) and carrot (dicot) protoplasts. Multiple enhancer elements increased expression in sugar-cane, by up to 400-fold for the artificial Emu promoter relative to the CaMV 35S promoter. The relative expression strengths of promoters varied substantially between the species. Sugar-cane also differed in some respects from previously tested species in the family Poaceae. For example, in sugar-cane the nopaline synthase and CaMV 35S promoters were of equivalent strength, and insertion of Adh1 intron 1 into the 5 transcribed region decreased expression strength.     

A linkage study in seven breast cancer families.

Seven breast cancer families are examined for evidence of linkage to a site in the region of 17q12-q21, by using five markers. The families constitute a subset of a larger series of familial breast cancer; the seven families were selected because constitutional DNA was available on informative members, either from clinical samples or extracted from paraffin blocks. Two-point lod scores are reported. The maximum lod score, 0.8824, is obtained with marker NM23 at theta = 0. This is clearly not significant in itself; however, when taken in context with evidence from existing reports, it provides support for linkage to this region.     

Carbon uptake in Eurasian boreal forests dominates the high-latitude net ecosystem carbon budget

Arctic-boreal landscapes are experiencing profound warming, along with changes in ecosystem moisture status and disturbance from fire. This region is of global importance in terms of carbon feedbacks to climate, yet the sign (sink or source) and magnitude of the Arctic-boreal carbon budget within recent years remains highly uncertain. Here, we provide new estimates of recent (2003–2015) vegetation gross primary productivity (GPP), ecosystem respiration (R_eco), net ecosystem CO₂ exchange (NEE; R_eco − GPP), and terrestrial methane (CH₄) emissions for the Arctic-boreal zone using a satellite data-driven process-model for northern ecosystems (TCFM-Arctic), calibrated and evaluated using measurements from >60 tower eddy covariance (EC) sites. We used TCFM-Arctic to obtain daily 1-km² flux estimates and annual carbon budgets for the pan-Arctic-boreal region. Across the domain, the model indicated an overall average NEE sink of −850 Tg CO₂-C year⁻¹. Eurasian boreal zones, especially those in Siberia, contributed to a majority of the net sink. In contrast, the tundra biome was relatively carbon neutral (ranging from small sink to source). Regional CH₄ emissions from tundra and boreal wetlands (not accounting for aquatic CH₄) were estimated at 35 Tg CH₄-C year⁻¹. Accounting for additional emissions from open water aquatic bodies and from fire, using available estimates from the literature, reduced the total regional NEE sink by 21% and shifted many far northern tundra landscapes, and some boreal forests, to a net carbon source. This assessment, based on in situ observations and models, improves our understanding of the high-latitude carbon status and also indicates a continued need for integrated site-to-regional assessments to monitor the vulnerability of these ecosystems to climate change.     

Getting to the root of the problem: new evidence for the use of plant root foods in Mesolithic hunter-gatherer subsistence in Europe

Vegetation History and Archaeobotany - This paper presents new evidence for the harvesting of edible plant roots and tubers at Northton, a Mesolithic hunter-gatherer site on Harris, in the Western...     

Management of raised blood pressure in New Zealand: a discussion document.

A report to the National Advisory Committee on Core Health and Disability Support Services, New Zealand, on the management of raised blood pressure recommends that decisions to treat raised blood pressure should be based primarily on the estimated absolute risk of cardiovascular disease rather than on blood pressure alone. In general, patients with a blood pressure of 150-170 mm Hg systolic or 90-100 mm Hg diastolic, or both, should be given treatment to lower blood pressure if the risk of a major cardiovascular disease event in 10 years is more than about 20%. The results of clinical trials indicate that, at this level of absolute risk, 150 people would require treatment to reduce the annual number of cardiovascular events by about one. Implementation of these recommendations may result in a smaller proportion of people aged under 60, particularly women, receiving treatment but an increased proportion of older people treated. In the absence of specific contraindications, low dose diuretics and low dose beta blockers should be considered for first line treatment, since for only these drug groups is there direct evidence of reduced risk of stroke and coronary disease in people with raised blood pressure.