Airborne pollen in Genoa (NW-Italy): a comparison between two pollen-sampling stations

A comparison between two pollen-sampling stationsin the city area of Genoa is presented. The samplingsites are placed 3 km apart, respectively in theeastern urban area (St. Martino Hospital – S.M.) andin the historical centre (Botanical Garden – B.G.).Pollen sampling was carried out during the years1995–1997 at the two different sites by volumetricHirst-type sampler and then compared. The dailyairborne pollen concentration of Urticaceae, Poaceae,Cupressaceae/Taxaceae, Corylaceae/Betulaceae andOleaceae resulted prevailingly higher at S.M., while a good correspondence was observed from a phenologicpoint of view. Asteraceae have shown the bestqualitative-quantitative consistency. In springtime adifference was recorded for Urticales, maybe due tolocal occurence (B.G.) of Broussonetia papyrifera(Moraceae). On the whole, the correspondence betweenthe two different sampling stations proved to besatisfactory.     

Winners and losers in the competition for space in tropical forest canopies

Trees compete for space in the canopy, but where and how individuals or their component parts win or lose is poorly understood. We developed a stochastic model of three‐dimensional dynamics in canopies using a hierarchical Bayesian framework, and analysed 267 533 positive height changes from 1.25 m pixels using data from airborne LiDAR within 43 ha on the windward flank of Mauna Kea. Model selection indicates a strong resident's advantage, with 97.9% of positions in the canopy retained by their occupants over 2 years. The remaining 2.1% were lost to a neighbouring contender. Absolute height was a poor predictor of success, but short stature greatly raised the risk of being overtopped. Growth in the canopy was exponentially distributed with a scaling parameter of 0.518. These findings show how size and spatial proximity influence the outcome of competition for space, and provide a general framework for the analysis of canopy dynamics.     

Collection,particle sizing and detection of airborne viruses

Viruses that affect humans, animals and plants are often dispersed and transmitted through airborne routes of infection. Due to current technological deficiencies, accurate determination of the presence of airborne viruses is challenging. This shortcoming limits our ability to evaluate the actual threat arising from inhalation or other relevant contact with aerosolized viruses. To improve our understanding of the mechanisms of airborne transmission of viruses, air sampling technologies that can detect the presence of aerosolized viruses, effectively collect them and maintain their viability, and determine their distribution in aerosol particles, are needed. The latest developments in sampling and detection methodologies for airborne viruses, their limitations, factors that can affect their performance and current research needs, are discussed in this review. Much more work is needed on the establishment of standard air sampling methods and their performance requirements. Sampling devices that can collect a wide size range of virus-containing aerosols and maintain the viability of the collected viruses are needed. Ideally, the devices would be portable and technology-enabled for on-the-spot detection and rapid identification of the viruses. Broad understanding of the airborne transmission of viruses is of seminal importance for the establishment of better infection control strategies.     

Seasonal variation of fungal propagules in a fruit market environment, Nagpur (India)

The concentration of airborne fungal spores in a marketenvironment was examined to provide basic information needed to evaluatethe importance of varying levels and heterogeneity. Sampling has beencarried out by rotorod sampler and exposed Petri plate method to obtainthe quantitative and qualitative estimations respectively.Aspergillus was the most frequent and predominant genusdetected. Cladosporium, Penicillium and Alternariaspores were also fairly abundant which are well known as allergenic andpathogenic. The high concentration of airborne spores was recordedduring December–January. While the maximum concentration ofAspergillus was found during summer months in the marketenvironment.