Application of shoot growth rules for understanding responses to pruning.

Knowledge of fruit tree shoot types is helpful to explain why pruning is often not successful in reducing tree size. In many horticultural circumstances, epicormic shoot growth can be considered as being almost exclusively stimulated by severe pruning of large branches (older than one year old) or strong water shoots in which sylleptic shoots have previously grown and "used up" the locations in close proximity to the pruning cut where proleptic buds would have been present in a less vigorous shoot. The strong growth response to heavy pruning is natural and is the primary reason why pruning cannot be relied upon exclusively to control tree size when trees are grown in highly fertile soils without size-controlling rootstocks. This chapter deals with understanding responses to pruning of fruit trees by application of shoot growth rules.

Growth and foliar nutrition of a hybrid poplar clone following the application of a mixture of papermill biosolids and lime mud

Fertilization of hybrid poplar (HP) plantations with papermill by-products is a promising solution to improve soil fertility and nutrient availability, increase plantation productivity, and provide added value to these materials that would otherwise be incinerated or sent to the landfill. We assessed the growth and foliar nutrition of a HP clone (Populus x. canadensis × P. maximowiczii) at six plantation sites aged three to five years in southern Quebec, Canada. Sites received a fertilization treatment consisting of a mixture of papermill biosolids (120 to 140 t ha-1, depending on site) and lime mud (10 to 15 t ha-1) before being planted, or no fertilization (control). Tree growth was significantly improved by fertilization, with fertilized trees showing a mean annual height increment of 1.3 m (all-site mean; SD = 0.2), compared with 0.5 m (SD = 0.4) for unfertilized trees. Foliar Ca and Mg increased following fertilization and levels met optimal thresholds at all sites, whereas N, P, and K concentrations also increased but nutritional deficiencies remained for these elements at several sites. Our results confirm the benefits of fertilizing hybrid poplars with papermill by-products, but indicate that adjustments in application rates or type of by-products could be made in order to fully satisfy nutritional requirements and thus optimize tree growth.

PCTBC: Power Control Tree-Based Cluster Approach for Sybil Attack in Wireless Sensor Networks

Wireless Sensor Networks (WSNs) have come across several things which include collecting data, handling data and distribution for super visioning specific applications such as the services needed, managing anything that occurred naturally, etc. They totally rely on applications. Therefore, the WSNs are classified under major networks. This is very essential. It can be defined as a network of networks that helps in proper flow of data. The main characteristics of WSN include its continuous changes in topologies, connected nodes with several chips and tunic routing protocol. There should be the better utilization of the available resources so that its life span may exceed. There should be an effective usage of available assets to avoid the waste. In our research, we propose a hybrid approach, namely, the Power Control Tree-Based Cluster (PCTBC) to identify the Sybil attacks in WSNs. It employs several stages structured clustering of nodes based on position and identity verification. This approach is utilized for the usage of energy consumption, effectiveness of detecting Sybil attacks inside clusters. The main aspects put into consideration are the efficient routing protocol of the distance between the hops and the energy power remains, where the distance between the hops is being computed using the Received Signal Strength Indication (RSSI) and also the packet transmission can be properly tuned on the basis of the distance. Also, the proposed approach considers the energy consumption for the transmission of the defined packet.

Anti-malarial Drugs are Not Created Equal for SARS-CoV-2 Treatment: A Computational Analysis Evidence

Background: The evolution of the pandemic is putting national healthcare systems to a huge effort worldwide and at present, there is no preferred antiviral treatment for COVID-19. Recently, SARS-Cov-2 protease structure was released and may be exploited in in-silico studies in order to conduct molecular docking analysis. Methods: In particular, we compared the binding of two used antimalarial drugs (i.e. chloroquine and hydroxychloroquine) which showed some potential clinical effects in COVID-19 patients, using as positive control tree antiviral recognized compounds, ritonavir, lopinavir and darunavir. Results: Our results showed that hydroxychloroquine but not chloroquine exhibited a significant binding activity to the main protease similar to that possessed by protease inhibitors tested for other viral infections. Conclusion: Our data suggest that hydroxychloroquine may exert additional direct antiviral activity compared to chloroquine. In the absence of clinical studies comparing the efficacy of these two compounds, hydroxychloroquine may offer additional effects and may be considered as first choice.

A Study of Disaster Prevention and Characteristics of Landslides Triggered by the 2019 Typhoon Mitag in Samcheok

Close on the heels of the East Coast Forest Fires (ECFF) in April 2000, Samcheok in the region witnessed landslides in October 2019. Therefore, it is imperative to understand the association between forest fire and slope stability. Accordingly, survey plots were set up around the site of the landslide to investigate micro-topography, forest structure, and growth environment. The results revealed that B plots scored high on appearance and the density of trees, while A plots had high values on the H/D ratio. Further, it is important to control tree density in the restored forests because the H/D ratio, which induces slope stability, exceeds suitable values at both A and B plots, resulting in intense competition among the trees growing in the affected sites. The findings are useful for proposing a mountain management project to prevent sediment-related disasters. Moreover, they would aid in evaluating the root cohesion of trees contributing to slope stability on the east coast region of Gangwon-do, which is prone to disasters such as large-scale forest fires, heavy rains, and landslides.

Effects of Climatic Variability and Non-Climatic Factors on Mopane Worms’ (Gonimbrasia Belina) Distribution and Livelihood Options in North Central Namibia

Mopane worms (Gonimbrasia belina) are an important source of food and income for households in Northern Namibia. However, their access and availability in many areas have declined, mainly due to climate change and human activities. This has affected many households’ livelihoods, making them vulnerable to poverty and food insecurity. With these factors in mind, this study sought to identify the extent to which the availability and distribution of mopane worms are influenced in the Tsandi and Okahao constituencies. The study used structured questionnaires to collect information from households in the study area, to interview key informants, and to carry out group discussions. A total of 70 households and 6 key informants were interviewed, along with 4 focus group discussions that were carried out to elicit perceptions, and to obtain views on the availability of mopane worms, and possible causes of the decline in the study area. Data were analysed using descriptive statistics, while GIS was used to determine trends in vegetation cover, temperature and rainfall in the area. The rainfall trend indicates variability, with a generally declining trend. A slight increase in temperature has been observed too. Vegetation showed a browning trend in the study area, indicating declining habitats of mopane worms. The results have indicated that more women depend on mopane worms for survival, mainly as a source of income. Thus the decline in their availability greatly affects their food sources and their income diversification opportunities. Trading was found to be an important form of employment for the unemployed rural people, but with the potential to generate higher income levels that can improve their livelihoods. Moreover, despite the climatic factors, human activities seemed to indicate a greater influence on the availability of mopane worms, due to activities such as overharvesting, land clearing for agriculture and household use/fencing. Thus, there is a greater need to control the harvesting of mopane worms and to control tree cutting activities in order to reduce the impacts of climatic and non-climatic factors on their availability.