Energy Stored in Above-Ground Biomass Fractions and Model Trees of the Main Coniferous Woody Plants

The paper considers energy stored in above-ground biomass fractions and in model trees of the main coniferous woody plants (Picea abies (L.) H. Karst., Abies alba Mill., Pinus sylvestris (L.), Larix decidua Mill.), sampled in 22 forest stands selected in different parts of Slovakia. A total of 43 trees were felled, of which there were 12 spruces, 11 firs, 10 pines, and 10 larches. Gross and net calorific values were determined in samples of wood, bark, small-wood, twigs, and needles. Our results show that these values significantly depend on the tree species, biomass fractions, and sampling point on the tree. The energy stored in the model trees calculated on the basis of volume production taken from yield tables increases as follows: spruce < fir < pine < larch. Combustion of tree biomass releases an aliquot amount of a greenhouse gas—CO2, as well as an important plant nutrient, nitrogen—into the atmosphere. The obtained data must be taken into account in the case of the economic utilization of energy stored in the fractions of above-ground tree biomass and in whole trees. The achieved data can be used to assess forest ecosystems in terms of the flow of solar energy, its accumulation in the various components of tree biomass, and the risk of biomass combustion in relation to the release of greenhouse gases.

Thermal conductivity of untreated and chemically treated poplar bark and wood

The thermal insulation properties of bark and wood of a poplar tree (Populus nigra × alba) were investigated using a guarded hot plate device (GHP) and a purpose-built miniature heat flow meter (Mini-HFM). To reduce their density and improve their performance as insulation material, bark and wood were chemically treated. The correlation between thermal conductivity and test temperature as well as between thermal conductivity and material moisture was investigated. By means of the treatment 44 and 34% of the mass of bark and wood, respectively, was removed and the equilibrium moisture content of the both materials decreased significantly. For untreated bark, a thermal conductivity of 0.071 Wm−1 K−1 and 0.140 Wm−1 K−1, respectively, were determined in transverse and axial direction. For wood, measurements showed comparably higher conductivities of 0.078 Wm−1 K−1 and 0.204 Wm−1 K−1 in transverse and axial direction. By reducing density, thermal conductivity of bark decreased up to 24%, whereas for wood reductions between 10 and 35% were found. It was shown that the self-constructed Mini-HFM is a useful and reliable instrument to determine the thermal conductivity on a small wood sample in the three main anatomical directions.

Reflections on a Career in Plant Virology: A Chip Floating on a Stream

At the time I entered college and for a few years afterward, I had very few concrete goals. Hence, my progress was more a matter of luck than planning and was somewhat analogous to a small wood chip floating down a slow stream, bumping into various objects tossed and turned hither and thither, all the while being surrounded by larger and more appealing chips. I have been extremely lucky to have been associated with numerous helpful and knowledgeable mentors, colleagues, postdocs, students, and coworkers whose advice had major impacts on my life. Therefore, throughout this article, I have attempted to acknowledge central individuals who contributed to my progress in academia and to highlight the positive bumps to my chip on the steam that affected the directions of my career. Expected final online publication date for the Annual Review of Virology, Volume 8 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Evaluation of the potential amount of dendromass left in beech stands of the Little Carpathians after intentional felling and its economic assessment

The paper deals with the determination of the amount of logging residues including merchantable timber volume (brush) left in the beech stands for further use. Logging residues were recorded in all types of intentional felling starting with intentional improvement felling up to 50 years and ending with intentional regeneration felling. The potential amount of biomass left was divided into the share of brush and the share of small wood. The parameter was monitored for 3 years and all measured values were then statistically evaluated and related to 1 m3 of intentional felling in beech stands. A partial goal of this publication is characterization of economic impacts of the proposal for processing the recorded volume of logging residues left in the beech stands on the forest branch in Smolenice. The economic impacts are characterized in two proposed and mutually compared scenarios. The first scenario considers framework contractors for logging works with their own machines, i.e. by assignments, as a mediation of service invoiced for the assumed amount (m3) forwarded to the roadside landing, with the ownership of the forwarded dendromass belonging to Lesy SR (Forests of the Slovak Republic). Then, the dendromass is sold from the roadside landing to customers who are going to transport and process it at their own expense. The second scenario considers sales of assumed amounts of left dendromass including brush to customers who will provide for its transport and processing on the identified roadside landing within a set deadline under obligation to return the site to its original condition if there is possible damage. In this case, Lesy SR would be only a control body supervising labour quality and set-up technological procedures.

Naturalization and spread of the alien species Ozognathus cornutus (LeConte, 1859) (Coleoptera: Ptinidae: Ernobiinae) in Italy

Ozognathus cornutus (LeConte, 1859) (Coleoptera: Ptinidae: Ernobiinae), species native to North America, is a saproxylophagous species and is known to feed on decaying tissues within conspicuous galls and on vegetal decaying organic material such as dried fruits or small wood shavings and insect excrements in galleries made by other woodboring species. A few years after the first record in 2011, its naturalization in Italy is here reported. The insect was found as successor in galls of Psectrosema tamaricis (Diptera Cecidomyiidae), Plagiotrochus gallaeramulorum, Andricus multiplicatus and Synophrus politus (Hymenoptera Cynipidae). The galls seem to have played an important ecological role in speeding up the naturalization process. The lowest proportion of galls used by O. cornutus was recorded for P. tamaricis (23%), the only host belonging to Cecidomyiidae, while the percentages recorded for the other host species, all Cynipidae forming galls on oaks, were higher: 43.6%, 61.1% and 76.9% in A multiplicatus, S. politus and P. gallaeramulorum, respectively. Although O. cornutus is able to exploit other substrates like dried fruits and vegetables, for which it could represent a potential pest, it prefers to live as a successor in woody and conspicuous galls, which thus can represent a sort of natural barrier limiting the possible damages to other substrates.

TaqMan probe assays on different biological samples for the identification of three ambrosia beetle species, Xylosandrus compactus (Eichoff), X. crassiusculus (Motschulsky) and X. germanus (Blandford) (Coleoptera Curculionidae Scolytinae)

Molecular assays based on qPCR TaqMan Probes were developed to identify three species of the genus Xylosandrus, X. compactus, X. crassiusculus and X. germanus (Coleoptera Curculionidae Scolytinae). These ambrosia beetles are xylophagous species alien to Europe, causing damages to many ornamental and fruiting trees as well as shrubs. DNA extraction was carried out from adults, larvae and biological samples derived from insect damages on infested plants. For X. compactus, segments of galleries in thin infested twigs were cut and processed; in the case of X. crassiusculus, raw frass extruded from exit holes was used, while DNA of X. germanus was extracted from small wood chips removed around insect exit holes. The assays were inclusive for the target species and exclusive for all the non-target species tested. The LoD was 3.2 pg/µL for the frass of X. crassiusculus and 0.016 ng/µL for the woody matrices of the other two species. Both repeatability and reproducibility were estimated on adults and woody samples, showing very low values ranging between 0.00 and 4.11. Thus, the proposed diagnostic assays resulted to be very efficient also on the woody matrices used for DNA extraction, demonstrating the applicability of the protocol in the absence of dead specimens or living stages.

Effect of heat treatment on shore-D hardness of some wood species

Hardness is an important wood property for several applications. Typically, it is necessary to use traditional methods, such as a universal test machine, to determine a wood’s hardness value. This work reports the hardness of some wood species before and after heat treatment (ThermoWood method) using the Shore-D hardness method. The Shore-D hardness value of untreated wood ranged between 35.3 for Limba wood and 77.2 for Santos wood. With heat treatment, hardness decreased, and the decrease was greater for samples that underwent harsher treatment (2 h at 212 °C). The decrease of hardness was highest for Sipo wood (14%) and the lowest for Afrormosia wood (2.5%). Analysis of variance tests showed that there was a significant difference between wood species, heat treatment, and the interaction between both variables at the chosen level of significance (P ≤ 0.05). Results showed that Shore-D hardness could be used to measure hardness directly in a production line or in small wood companies without using a universal test machine.

Antimicrobial Bacteria and Viruses Detected Through Systematic Sampling in the Childcare Environment

Background: Approximately two-thirds of children aged <5 years receive out-of-home child care. Childcare attendees have an increased risk of infections compared to children not in childcare settings, possibly due to their close contact in a shared environment. As multidrug-resistant organisms (MDROs) increasingly move from healthcare-associated to community settings, childcare can provide a venue for further transmission of these pathogens. Our objective was to evaluate the bioburden of pathogens present on fomites in childcare centers and how surface contamination changes over time. Methods: The study was conducted in the single-room play area of an Ypsilanti, Michigan, childcare center caring for children aged 3–5 years. Polyester swabs were used to collect surface samples from 16 locations in the room, including (1) laminate, wood and plastic tabletops and furniture; (2) a stainless steel sink and adjacent plastic trash bin; and (3) wood, metal and plastic toys. A water sample was also collected at a 17th site. Samples were collected twice weekly for 5 of 6 weeks, followed by 1 additional collection (September–October 2019). Tryptic soy agar was used for standard plate counts and selective media were used to identify methicillin-resistant Staphylococcus aureus (MRSA), Vvancomycin-resistant Enterococcus (VRE), and extended-spectrum β-lactamase (ESBL)–producing Enterobacteriaceae. Single-plex RT-PCR was used to detect norovirus and adenovirus. Results: Among 175 samples collected on 11 days, MRSA and ESBL-producing Enterobacteriaceae were detected from 10.3% (18 of 175) and 8.0% (14 of 175), respectively, of environmental specimens. No specimens were positive for VRE or norovirus. Adenovirus was detected in 20 of 175 specimens (11.4%). Median bioburden by site ranged from 85 CFU/mL to 2,510 CFU/mL. The highest median bioburden was observed at the sink (2,510 CFU/mL), followed by the plastic building block table (1,620 CFU/mL), the small wood blocks (1,565 CFU/mL) and water from a water play area and an adjacent tabletop (1,260 and 1,100 CFU/mL respectively). The highest single day bioburden was 273,000 CFU/mL at the sink. Conclusion: The presence of MDROs on childcare center fomites raised concern for exposure to these pathogens among vulnerable populations. More study is needed to determine the degree to which these contaminated fomites drive transmission between children. We found the highest bioburdens on sites where children played or washed with water, identifying potential targets for more frequent cleaning.Funding: NoneDisclosures: Emily T. Martin reports a consulting from Pfizer.

Effects of Virtual Reality on Student Learning in Materials and Methods Course

Virtual Reality (VR) offers a method of active and interactive learning. In this research, a VR-based simulated environment is used to help students gain an understanding in the sequencing of construction activities within an undergraduate materials and methods course. The VR simulation was developed to augment traditional classroom learning methods. The sequencing simulation allows students to freely navigate through the simulation and walk through the steps of the construction for a small wood frame structure. The simulation was developed for both immersive and non-immersive desktop-based simulations. During early studies, it was found that students were receptive of the technology and perceived a benefit in understanding spatial qualities as well as components of assembly but actual effects of learning were not identified. The current study explores the actual effects of student learning when incorporating simulation into the coursework. This paper discusses the comparison of students learning from a control group where the simulation was not used to the learning of a group who utilized the desktop-based simulation in addition to traditional classroom methods.