Aims: Examine the regulation of a spore coat protein and the effects on spore properties. Methods and Results: A c. 23 kDa band in coat/exosporial extracts of Bacillus anthracis Sterne spores varied in amount depending upon the conditions of sporulation. It was identified by MALDI as a likely orthologue of ExsB of Bacillus cereus. Little if any was present in an exosporial preparation with a location to the inner coat/cortex region established by spore fractionation and immunogold labelling of electron micrograph sections. Because of its predominant location in the inner coat, it has been renamed Cotc. It was relatively deficient in spores produced at 37°C and when acidic fermentation products were produced a difference attributable to transcriptional regulation. The deficiency or absence of Cotc resulted in a less robust exosporium positioned more closely to the coat. These spores were less hydrophobic and germinated somewhat more rapidly. Hydrophobicity and appearance were rescued in the deletion strain by introduction of the cotc gene. Conclusions: The deficiency or lack of a protein largely found in the inner coat altered spore hydrophobicity and surface appearance. Significance and Impact of the Study: The regulated synthesis of Cotc may be a paradigm for other spore coat proteins with unknown functions that modulate spore properties in response to environmental conditions.

We provide both the precise value and general upper and lower bounds for the Gromov-Hausdorff distance d GH pS m , S n q between spheres S m and S n (endowed with the round metric) for 0 ď m ă n ď 8. Some of these lower bounds are based on certain topological ideas related to the Borsuk-Ulam theorem. Via explicit constructions of (optimal) correspondences we prove that our lower bounds are tight in the cases of d GH pS 0 , S n q, d GH pS m , S 8 q, d GH pS 1 , S 2 q, d GH pS 1 , S 3 q and d GH pS 2 , S 3 q. We also formulate a number of open questions. CONTENTS 1. Introduction 1.1. Overview of our results 1.2. Discussion 1.3. Acknowledgements 2. Preliminaries 2.1. Notation and conventions about spheres. 3. Some general lower bounds 3.1. The proof of Proposition 1.3 3.2. Other lower bounds 4. The proof of Theorem 1 Space filling curves. Spherical suspensions. The proof of Theorem 6. 5. A Borsuk-Ulam theorem for discontinuous functions and the proof of Theorem 2 5.1. A succinct proof of Theorem 8 5.2. The proofs of Theorem 2 and 3 6.

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Utilization of wind and solar energy at permanent and temporary polar research stations is reviewed in light of the ongoing search for a diesel fuel replacement. Renewable energy sources are available that can help to reduce the need to transport and handle bulk fossil fuels in remote and extreme cold climate regions. Fundamental concepts that underpin these technologies are described, and some of the strategies devised to meet the physical and logistical challenges of cold climate operations are outlined. Factors that limit the penetration of intermittent renewable energy sources are discussed, and the evolution of wind-thermal devices is examined in the context of producing year-round heat and power.

Diplodia corticola is a fungal pathogen contributing to oak (Quercus spp.) decline in the Mediterranean and US (Félix et al., 2017; Ferreira et al., 2021). In 2021, this pathogen was detected in Tennessee (TN) causing branch dieback in Q. alba (Onufrak et al., 2022). In September 2021, a matured pin oak (Q. palustris) with wilted leaves and elongated branch cankers was observed in the State Botanical Garden of Tennessee-Knoxville (TN, US). Small sections of the phloem were sampled from canker margins of a symptomatic branch using a sterile scalpel, surface sterilized, and plated onto potato dextrose agar amended with antibiotics (PDA++) (Gazis et al. 2018). Three days later, a fungal isolate resembling D. corticola was cultured on ½ PDA. Diplodia corticola is characterized on half-strength PDA by fast growth, irregular margins, and dense white mycelium that turns dark, grayish as the mycelium matures (Úrbez-Torres et al., 2010; Alves et al., 2004). Total genomic DNA was extracted from this isolate following Gazis et al. (2018), and the internal transcribed spacer (ITS), large ribosomal subunit (LSU), and transcription elongation factor 1-α (ef1-α) were amplified (Ferreira et al. 2021). Resulting PCR products were sequenced and assembled into consensus sequences using Unipro UGENE v. 44.0 (Okonechnikov et al., 2012). Each consensus sequence identity was determined using BLAST on the NCBI nucleotide database, restricted to type material. The ITS (accession OQ189888), ef-1α (accession OQ201608), and LSU (accession OQ189887) sequences had a 99.6% (accession KF766156.1), 98.6% (accession XM_020275852.1), and 100% (accession KF766323.1) identity match with D. corticola type culture CBS112549, respectively. To complete Koch’s postulates and assess potential pathogenicity on economically and ecologically relevant oaks, 10 pin (Q. palustris; caliper 15.6 ± 2.0 mm), 10 overcup (Q. lyrata; caliper 15.1 ± 2.4 mm), and 10 sawtooth (Q. acutissima; 16.1 ± 2.1 mm) oaks were acclimated in the greenhouse for 1 week prior to the experiment. Five trees of each species were then randomly inoculated at 30 cm above the soil line with a 3 mm diameter plug of D. corticola (grown for 10 days on PDA; Sitz et al. 2017). To serve as a control, the remaining 5 trees for each species received a 3 mm diameter PDA plug. Fifteen days post-inoculation, seepage was observed in D. corticola-inoculated pin (5/5 trees), overcup (4/5 trees), and sawtooth (4/5 trees) oaks. No seepage from wound sites was noted in control trees. Cankers were exposed, photographed, and then measured using ImageJ (Rasband, 2012). Using a sterile scalpel, four wood chips were excised from canker margins and plated onto PDA++. We recovered D. corticola from symptomatic inoculated pin (5/5 trees), overcup (4/5 trees), and sawtooth (4/5 trees) oaks and confirmed species identity by extracting DNA and amplifying the ITS, ef-1α, and LSU regions as described above (Gazis et al., 2018; Ferreira et al., 2021). The resulting consensus sequences matched the D. corticola type culture (CBS112549) ITS (99.0%-99.8% identity), ef-1α (91.0%-99.1% identity), and LSU (96.9%-100% identity) barcoding regions. Cankers were significantly larger in D. corticola-inoculated pin (4.7 ± 1.5 cm2; P = 0.003), overcup (6.8 ± 2.9 cm2; P = 0.009), and sawtooth (5.1 ± 1.3 cm2; P = 0.001) oaks in comparison to the control trees from these groups. Based on current reports, this is the first record of D. corticola causing dieback in pin oak (Q. palustris) in TN.