Overcoming the coupled climate and biodiversity crises and their societal impacts.

Earth's biodiversity and human societies face pollution, overconsumption of natural resources, urbanization, demographic shifts, social and economic inequalities, and habitat loss, many of which are exacerbated by climate change. Here, we review links among climate, biodiversity, and society and develop a roadmap toward sustainability. These include limiting warming to 1.5°C and effectively conserving and restoring functional ecosystems on 30 to 50% of land, freshwater, and ocean "scapes." We envision a mosaic of interconnected protected and shared spaces, including intensively used spaces, to strengthen self-sustaining biodiversity, the capacity of people and nature to adapt to and mitigate climate change, and nature's contributions to people. Fostering interlinked human, ecosystem, and planetary health for a livable future urgently requires bold implementation of transformative policy interventions through interconnected institutions, governance, and social systems from local to global levels.

Diverse functional responses to drought in a Mediterranean-type shrubland in South Africa.

• Mediterranean-type ecosystems contain 20% of all vascular plant diversity on Earth and have been identified as being particularly threatened by future increases in drought. Of particular concern is the Cape Floral Region of South Africa, a global biodiversity hotspot, yet there are limited experimental data to validate predicted impacts on the flora. In a field rainout experiment, we tested whether rooting depth and degree of isohydry or anisohydry could aid in the functional classification of drought responses across diverse growth forms. • We imposed a 6-month summer drought, for 2 yr, in a mountain fynbos shrubland. We monitored a suite of parameters, from physiological traits to morphological outcomes, in seven species comprising the three dominant growth forms (deep-rooted proteoid shrubs, shallow-rooted ericoid shrubs and graminoid restioids). • There was considerable variation in drought response both between and within the growth forms. The shallow-rooted, anisohydric ericoid shrubs all suffered considerable reductions in growth and flowering and increased mortality. By contrast, the shallow-rooted, isohydric restioids and deep-rooted, isohydric proteoid shrubs were largely unaffected by the drought. • Rooting depth and degree of iso/anisohydry allow a first-order functional classification of drought response pathways in this flora. Consideration of additional traits would further refine this approach.

Experimental biogeography: the role of environmental gradients in high geographic diversity in Cape Proteaceae.

One of the fundamental dimensions of biodiversity is the rate of species turnover across geographic distance. The Cape Floristic Region of South Africa has exceptionally high geographic species turnover, much of which is associated with groups of closely related species with mostly or completely non-overlapping distributions. A basic unresolved question about biodiversity in this global hotspot is the relative importance of ecological gradients in generating and maintaining high geographic turnover in the region. We used reciprocal transplant experiments to test the extent to which abiotic environmental factors may limit the distributions of a group of closely related species in the genus Protea (Proteaceae), and thus elevate species turnover in this diverse, iconic family. We tested whether these species have a "home site advantage" in demographic rates (germination, growth, mortality), and also parameterized stage-structured demographic models for the species. Two of the three native species were predicted to have a demographic advantage at their home sites. The models also predicted, however, that species could maintain positive population growth rates at sites beyond their current distribution limits. Thus the experiment suggests that abiotic limitation under current environmental conditions does not fully explain the observed distribution limits or resulting biogeographic pattern. One potentially important mechanism is dispersal limitation, which is consistent with estimates based on genetic data and mechanistic dispersal models, though other mechanisms including competition may also play a role.

Antimicrobials in animal agriculture: parables and policy.

In addition to the scientific, economic, regulatory and other policy factors that impact on antimicrobial decision-making in different jurisdictions around the world, there exist ethical, social and cultural bases for the contemporary use of these products in animal agriculture. Thus, the use of the word 'parable' to describe the contemporary moral stories that help to guide ethical antimicrobial use practices and broader policy decisions in animal agriculture is appropriate. Several of these stories reflect difficult decisions that arise from conflicting moral imperatives (i.e. both towards animal welfare and towards human health). Understanding the factors that combine to define the past and present paradigms of antimicrobial usage is crucial to mapping a path forward. There exist barriers, as well as opportunities, for advancing scenarios for reducing antimicrobial usage under a variety of voluntary, regulatory and legal policy frameworks. Any new approaches will ideally be structured to extend the use of present-day antimicrobials into the future, to provide novel alternatives for regulating any newly introduced antimicrobial products so as to maximize their useful life span and to ensure the optimal use of these products in animal agriculture to protect not only the health of animals and the interests of animal health/agriculture stakeholders, but also the human health and the interests of the public at large. A full range of policy approaches, which span the realm from strictly enforced regulations and laws to voluntary guidelines and compliance, should be explored with respect to their risks and benefits in a variety of worldwide settings and in full consideration of a range of stakeholder values.

Polymerase chain reaction and restriction fragment length polymorphism mediated detection and speciation of Candida spp causing intraocular infection.

PURPOSE: To determine the usefulness of polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis in the identification and speciation of Candida spp that causes ocular infection. METHODS: Oligonucleotide primers based on the cytochrome P450 L1 A1 demethylase gene were used to successfully amplify by PCR a single 1.0-kb and a single 500-bp DNA fragment from C. albicans, C. tropicalis, C. krusei, C. glabrata, C. parapsilosis, and C. pelliculosa genomic DNA. RFLPs within the PCR product were identified after restriction enzyme digestion. RESULTS: The sensitivity of the amplification reaction after two rounds of PCR was 10 fg genomic C. albicans DNA or one copy of the gene. No amplification product was obtained when DNA from C. guilliermondii, Aspergillus fumigatus, Fusarium solani, human leukocytes, or 10 species of bacteria was used as a template. Experiments with spiked normal vitreous demonstrated equal sensitivity as long as the volume of vitreous did not exceed 20% of the total PCR volume. RFLP analysis of the PCR product generated from each species obtained from the first- and second-round amplification products enabled species identification after digestion with specific endonucleases. Application of the technique to four clinical samples was successful. CONCLUSIONS: It is expected that the simplicity of the DNA extraction technique allied with the broad specificity of the outer primers for all ophthalmically relevant Candida spp and the sensitivity of the second-round PCR will aid in the detection of fungal DNA in small intraocular samples. PCR-RFLP analysis has great potential in the rapid detection and identification of Candida spp and in the provision of a useful laboratory tool for the future.

Nosocomial Malassezia pachydermatis bloodstream infections in a neonatal intensive care unit.

Malassezia pachydermatis, a lipophilic yeast, has been described to cause sporadic nosocomial bloodstream infections (BSI). Nosocomial outbreaks of M. pachydermatis BSI have never been described. A cluster of M. pachydermatis BSIs in the neonatal intensive care unit at Louisiana State University Medical Center, University Hospital provided the opportunity to investigate the epidemiology of this organism and apply molecular epidemiologic typing techniques. A case-patient was defined as any neonatal intensive care unit patient in University Hospital with a blood culture positive for M. pachydermatis from January 1, 1989, through August 15, 1991. Five patients met the case definition. Case-patients were premature as estimated by gestational age and required prolonged hospitalization. Case-patients received parenteral nutrition and intravenous lipids for twice as many days as randomly selected controls. No environmental source of M. pachydermatis was identified; however, infants on each side of a previously identified M. pachydermatis-colonized infant became colonized with M. pachydermatis during a 20-day period. Chromosomal analysis of five M. pachydermatis blood isolates from two case-patients had identical banding patterns. These data show that M. pachydermatis can cause nosocomial BSI outbreaks, that premature infants receiving parenteral nutrition and/or lipids may be at greatest risk and that transmission is most likely from person to person, probably via the hands of medical personnel.

Reinstatement of orienting behavior by d-amphetamine in rats with superior colliculus lesions.

The involvement of the nigrotectal pathway in the expression of visual orienting behavior was assessed by a combination of superior colliculus (SC) lesions and increased dopamine transmission produced by administration of d-amphetamine. Orienting behavior elicited by apparently moving or stationary light displays, its habituation, and recovery were observed. In intact animals, amphetamine injections had a small but reliable effect on the habituation of orienting behaviors. Rats with SC lesions did not orient to the lights. Amphetamine-injected rats with SC lesions did orient, and the topography of their orienting behavior, rate of habituation, and recovery of orienting with changes in the light display were comparable to those of the intact animal. These results suggest a view of SC-lesion-impaired orienting behavior as a disturbance of sensory attention and emphasize the interaction of the SC and other neural systems in processes mediating the direction of attention.

Effect of visual experience on the habituation of orienting behavior.

Orienting behavior elicited by novel visual and auditory stimuli was examined in light-reared (LR) and dark-reared (DR) rats at 30, 60, 90, or 120 days of age. Orienting behavior was assessed by examining the rat's ability to interrupt ongoing licking and perform appropriate head and postural adjustments when apparently moving or stationary light displays or tones were presented. When the lights were first presented to the LR and DR rats, their orienting behavior did not differ at any of the ages examined. However, age and visual experience did influence habituation and recovery of orienting with changes in the light display. The older DR rats habituated with fewer repeated presentations of the light displays than their LR counterparts and did not recover orienting as effectively to all the subsequent changes of the light displays. The younger LR and DR rats did not differ reliably. These results are discussed with regard to the nature of the habituation process for rodents and the relation between visual experience and habituation of attentional responses.

Effects of superior colliculus lesions on rats' orienting and detection of neglected visual cues.

Superior colliculus lesions generally result in a deficit in visual orienting described as sensory neglect. This observation was confirmed in this study: Rats with lesions did not orient to some stimuli that intact rats readily oriented to. However, rats with lesions did orient to stimuli that the intact rats treated as more salient. Also, when the less salient stimuli signaled aversive stimulation, the rats with lesions detected these stimuli. These findings suggest that superior colliculus lesions do not affect the detection of visual stimuli that have been neglected.

Toewebs as a source of gram-negative bacilli.

The prevalence of Gram-negative bacilli on the toewebs was 8% in normal students, 24% in hospital outpatients with suspected Tinea pedis, 41% in industrial workers wearing protective clothing and 58% in coal miners. Prevalence was greatest in those exposed to wet working conditions. In miners, the presence of Gram-negative bacilli was related to symptoms of itching/soreness and cracking/fissuring, and was negatively related to malodour, but this latter trend was reversed in outpatients and in industrial workers. The feet are a source of many 'enteric' and 'environmental' bacilli and could contribute to infection elsewhere than in the toewebs themselves.

Nail infections.

The increasing prevalence of onychomycoses, along with the wider range of organisms now recognized as potential pathogens, necessitates the accurate laboratory identification of the specific fungus involved. Although the majority of infections still are caused by dermatophyte and Candida species, many other nondermatophyte molds, such as Scytalidium dimidiatum, have been shown to be common agents of disease in certain geographic areas. It is well recognized that infections by nondermatophytes such as Scopulariopsis, Acremonium, and Aspergillus species occur worldwide. The availability of a range of new antifungal agents with various spectra of activity means that the exact identification of the pathogen is necessary to select the optimum treatment.

Growth, phenology and reproduction of an arid-environment winter ephemeral Dimorphotheca pluvialis in response to combined increases in CO2 and UV-B radiation.

The winter ephemeral Dimorphotheca pluvialis was grown in open-top chambers in ambient or elevated CO2 (350 or 650 micromol mol(-1)), combined with ambient (2.39 to 7.59 kJ m(-2) d(-1)) or increased (4.94 to 11.13 kJ m(-2) d(-1)) UV-B radiation. Net CO2 assimilation rate and leaf water use efficiency increased in elevated CO2, but increased UV-B did not affect gas exchange. Leaf biomass was greater under increased UV-B, but vegetative biomass was unaffected in elevated CO2. Initiation of reproduction was delayed, and proportional investment in reproductive biomass at harvest was reduced in elevated CO2. Increased UV-B stimulated reproduction, particularly in ambient CO2, but also in elevated CO2 at a later stage. Changes in reproductive phenology and prolonged development in elevated CO2 during the stressful late season could indirectly be detrimental to reproductive success of D. pluvialis, but stimulation of reproduction by enhanced UV-B may to some extent mitigate this.

The global distribution of ecosystems in a world without fire.

This paper is the first global study of the extent to which fire determines global vegetation patterns by preventing ecosystems from achieving the potential height, biomass and dominant functional types expected under the ambient climate (climate potential). To determine climate potential, we simulated vegetation without fire using a dynamic global-vegetation model. Model results were tested against fire exclusion studies from different parts of the world. Simulated dominant growth forms and tree cover were compared with satellite-derived land- and tree-cover maps. Simulations were generally consistent with results of fire exclusion studies in southern Africa and elsewhere. Comparison of global 'fire off' simulations with landcover and treecover maps show that vast areas of humid C(4) grasslands and savannas, especially in South America and Africa, have the climate potential to form forests. These are the most frequently burnt ecosystems in the world. Without fire, closed forests would double from 27% to 56% of vegetated grid cells, mostly at the expense of C(4) plants but also of C(3) shrubs and grasses in cooler climates. C(4) grasses began spreading 6-8 Ma, long before human influence on fire regimes. Our results suggest that fire was a major factor in their spread into forested regions, splitting biotas into fire tolerant and intolerant taxa.

The lipophilic yeasts: state of the art and prospects.

Malassezia yeasts (lipophilic yeasts), have been classified to include seven species. Although molecular methods such as sequencing of RNA and karyotyping were used to determine the species, traditional techniques are also being explored for their identification. These include studies of morphology and the utilization of individual lipids. Reports now show the predominance of individual species recovered from normal skin and from patients with diseases such as pityriasis versicolor and seborrhoeic dermatitis. The majority of systemic infections reported have been in the bloodstream of premature neonates. Clusters of cases have occurred and molecular techniques employed to study the epidemiology. With the development of discriminatory methods to determine individual species and strains present in disease and in nature, our understanding of the pathogenicity and the epidemiology of this genus can be advanced.

A glabrous Microsporum canis in Greater London.

A variant of Microsporum canis, which produces glabrous colonies on primary culture, has been frequently isolated from cases of scalp and body ringworm by this department. The records of this laboratory, which undertakes a diagnostic service covering most of the Greater London Area, show that the prevalence of M. canis among scalp infections has increased during the past ten years, and this species is presently responsible for the majority of cases diagnosed by culture. The glabrous form now represents one third of the scalp isolates of M. canis and it has been found most commonly in the West and South of Greater London.