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The subionospheric very low frequency (VLF) radio wave technique provides the possibility of investigating the response of the ionospheric D‐region to a diversity of transient and long‐term physical phenomena originating from above (e.g., energetic particle precipitation) and from below (e.g., atmospheric waves). In this study, we identify the periodicities that appear in VLF measurements and investigate how they may be related to changes in space weather and atmospheric activity. The powerful VLF signal transmitted from NAA (24 kHz) on the east coast of the United States, and received at Sodankylä, Finland, was analyzed. Wavelet transform, wavelet power spectrum, wavelet coherence, and cross‐wavelet spectrum were computed for daily averages of selected ionospheric, space weather, and atmospheric parameters from November 2008 until June 2018. Our results show that the significant VLF periods that appear during solar cycle 24 are the annual oscillation, semiannual oscillation, 121‐day, 86‐day, 61‐day, and solar rotation oscillations. We found that the annual oscillation corresponds to variability in mesospheric temperature and solar Lyman‐α (Ly‐α) flux and the semiannual oscillation to variability in space weather‐related parameters. The solar rotation oscillation observed in the VLF variability is mainly related to the Ly‐α flux variation at solar maximum and to geomagnetic activity variation during the declining phase of the solar cycle. Our results are important since they strengthen our understanding of the Earth’s D‐region response to solar and atmospheric forcing.

We present a new method for identifying the source regions of lightning‐generated whistlers observed at a fixed location. In addition to the spatial distribution of causative lightning discharges, we calculate the ratio of lightning discharges transmitted into ground detectable whistlers as a function of location. Our method relies on the time of the whistlers and the time and source location of spherics from a global lightning database. We apply this method to whistlers recorded at 15 ground‐based stations in the Automatic Whistler Detector and Analyzer Network operating between 2007 and 2018 and to located lightning strokes from the World Wide Lightning Location Network database. We present the obtained maps of causative lightning and transmission rates. Our results show that the source region of whistlers corresponding to each ground station is around the magnetic conjugate point of the respective station. The size of the source region is typically less than 2,000 km in radius with a small fraction of sources extending to up to 3,500 km. The transmission ratio is maximal at the conjugate point and decreases with increasing distance from it. This conforms to the theory that whistlers detected on the ground propagated in a ducted mode through the plasmasphere, and thus, the lightning strokes of their causative spherics must cluster around the footprint of the ducts in the other hemisphere. Our method applied resolves the whistler excitation region mystery that resulted from correlation‐based analysis methods, concerning the source region of whistlers detected in Dunedin, New Zealand.

In recent years, a small insect was discovered predating seeds of Crocanthemum canadense (Canada Frostweed or Rockrose), which is an endangered plant with small, localized populations in Nova Scotia. This insect targets primarily chasmogamous flowers (insect-pollinated, open flowers) but not cleistogamous flowers (self-pollinated, closed) of Canada Frostweed. This behavior is of concern because a decrease in the number of seeds produced by outcrossing could cause a decrease in genetic variance within populations at affected sites (e.g., Canadian Forces Base Greenwood, NS). We extracted DNA from larvae collected from chasmogamous flowers and used the mitochondrial cytochrome oxidase subunit I (COI) gene to barcode the DNA. Results from queries showed a 91% match to Mompha (Lepidoptera: Momphidae) species on GenBank, indicating that this insect was a member of the genus Mompha, but that this particular species was not in the database. To further characterize this lepidopteran, we collected and incu...

Pollen is a biological product obtained to manufacture tree, weed, and grass allergen extracts, used to diagnose and treat allergies. Genetic and environmental factors affect the composition of pollen, e.g., the plant varieties from which pollen are obtained, weather, and levels of air pollution during plant growth. Therefore, appropriate guidelines and training of personnel to perform the activities associated with pollen are essential to produce appropriate allergen extracts. Various regulatory institutions, which vary in different countries, including the Food and Drug Administration (FDA) in the USA, control how such products should be produced. For example, the FDA regulates the manufacturing of pollen extracts but not the quality of the pollen used to prepare them, relying on each manufacturer to set its own standards to do so. To the contrary, European regulatory agencies, including the European Medicines Agency, control both the quality of the pollen and the manufacturing process to produce pollen extracts. Regulatory agencies, allergen manufacturers, scientific institutions, and pollen collection entities should collaborate to develop and implement guidelines appropriate for worldwide use for both the collection and processing of pollen raw materials. This article provides an overview of the subject of pollen for use in allergen extracts.

The lace plant, Aponogeton madagascariensis, is an aquatic monocot that forms perforations in its leaves as part of normal leaf development. Perforation formation occurs through developmentally regulated programmed cell death (PCD). The molecular basis of PCD regulation in the lace plant is unknown, however ethylene has been shown to play a significant role. In this study, we examined the role of ethylene receptors during perforation formation. We isolated three lace plant ethylene receptors AmERS1a, AmERS1b and AmERS1c. Using quantitative PCR, we examined their transcript levels at seven stages of leaf development. Through laser-capture microscopy, transcript levels were also determined in cells undergoing PCD and cells not undergoing PCD (NPCD cells). AmERS1a transcript levels were significantly lower in window stage leaves (in which perforation formation and PCD are occurring) as compared to all other leaf developmental stages. AmERS1a and AmERS1c (the most abundant among the three receptors) had the highest transcript levels in mature stage leaves, where PCD is not occurring. Their transcript levels decreased significantly during senescence-associated PCD. AmERS1c had significantly higher transcript levels in NPCD compared to PCD cells. Despite being significantly low in window stage leaves, AmERS1a transcripts were not differentially expressed between PCD and NPCD cells. The results suggested that ethylene receptors negatively regulate ethylene-controlled PCD in the lace plant. A combination of ethylene and receptor levels determines cell fate during perforation formation and leaf senescence. A new model for ethylene emission and receptor expression during lace plant perforation formation and senescence is proposed.

Many field-collected fungal specimens are maintained in herbaria worldwide. These specimens contain an untapped wealth of taxonomic and ecological fungal biodiversity information. However, DNA can be difficult to obtain from preserved specimens. We present a DNA barcoding protocol specifically for preserved fungal specimens (ascomycetes and basidiomycetes). The E.C. Smith Herbarium at Acadia University houses 20,000 fungal specimens representative of northeastern North America. We achieved a DNA barcoding success rate of 18% from pre-1980 specimens (n = 39) using a kit-based DNA extraction protocol and sequencing of the full internal transcribed spacer (ITS) region of ribosomal DNA. This result surpassed success rates of previous protocols. We also explored the use of mini-barcodes from the ITS1 region only. Mini-barcodes (n = 13) demonstrated a 92% success rate in post-1980 specimens compared to full barcodes (46% success rate, n = 13) while retaining all the identification power of full barcodes in the examined specimens. Our approach will enable herbarium collections to be used more efficiently to populate DNA sequence databases such as GenBank. This approach will expand the number of reference DNA barcode sequences from vouchered fungal specimens within publicly available databases.