Insect pathogens as biological control agents: back to the future

The development and use of entomopathogens as classical, conservation and augmentative biological control agents have included a number of successes and some setbacks in the past 15 years. In this forum paper we present current information on development, use and future directions of insect-specific viruses, bacteria, fungi and nematodes as components of integrated pest management strategies for control of arthropod pests of crops, forests, urban habitats, and insects of medical and veterinary importance. Insect pathogenic viruses are a fruitful source of MCAs, particularly for the control of lepidopteran pests. Most research is focused on the baculoviruses, important pathogens of some globally important pests for which control has become difficult due to either pesticide resistance or pressure to reduce pesticide residues. Baculoviruses are accepted as safe, readily mass produced, highly pathogenic and easily formulated and applied control agents. New baculovirus products are appearing in many countries and gaining an increased market share. However, the absence of a practical in vitro mass production system, generally higher production costs, limited post application persistence, slow rate of kill and high host specificity currently contribute to restricted use in pest control. Overcoming these limitations are key research areas for which progress could open up use of insect viruses to much larger markets. A small number of entomopathogenic bacteria have been commercially developed for control of insect pests. These include several Bacillus thuringiensis sub-species, Lysinibacillus (Bacillus) sphaericus, Paenibacillus spp. and Serratia entomophila. B. thuringiensis sub-species kurstaki is the most widely used for control of pest insects of crops and forests, and B. thuringiensis sub-species israelensis and L. sphaericus are the primary pathogens used for medically important pests including dipteran vectors,. These pathogens combine the advantages of chemical pesticides and microbial control agents (MCAs): they are fast acting, easy to produce at a relatively low cost, easy to formulate, have a long shelf life and allow delivery using conventional application equipment and systemics (i.e. in transgenic plants). Unlike broad spectrum chemical pesticides, B. thuringiensis toxins are selective and negative environmental impact is very limited. Of the several commercially produced MCAs, B. thuringiensis (Bt) has more than 50% of market share. Extensive research, particularly on the molecular mode of action of Bt toxins, has been conducted over the past two decades. The Bt genes used in insect-resistant transgenic crops belong to the Cry and vegetative insecticidal protein families of toxins. Bt has been highly efficacious in pest management of corn and cotton, drastically reducing the amount of broad spectrum chemical insecticides used while being safe for consumers and non-target organisms. Despite successes, the adoption of Bt crops has not been without controversy. Although there is a lack of scientific evidence regarding their detrimental effects, this controversy has created the widespread perception in some quarters that Bt crops are dangerous for the environment. In addition to discovery of more efficacious isolates and toxins, an increase in the use of Bt products and transgenes will rely on innovations in formulation, better delivery systems and ultimately, wider public acceptance of transgenic plants expressing insect-specific Bt toxins. Fungi are ubiquitous natural entomopathogens that often cause epizootics in host insects and possess many desirable traits that favor their development as MCAs. Presently, commercialized microbial pesticides based on entomopathogenic fungi largely occupy niche markets. A variety of molecular tools and technologies have recently allowed reclassification of numerous species based on phylogeny, as well as matching anamorphs (asexual forms) and teleomorphs (sexual forms) of several entomopathogenic taxa in the Phylum Ascomycota. Although these fungi have been traditionally regarded exclusively as pathogens of arthropods, recent studies have demonstrated that they occupy a great diversity of ecological niches. Entomopathogenic fungi are now known to be plant endophytes, plant disease antagonists, rhizosphere colonizers, and plant growth promoters. These newly understood attributes provide possibilities to use fungi in multiple roles. In addition to arthropod pest control, some fungal species could simultaneously suppress plant pathogens and plant parasitic nematodes as well as promote plant growth. A greater understanding of fungal ecology is needed to define their roles in nature and evaluate their limitations in biological control. More efficient mass production, formulation and delivery systems must be devised to supply an ever increasing market. More testing under field conditions is required to identify effects of biotic and abiotic factors on efficacy and persistence. Lastly, greater attention must be paid to their use within integrated pest management programs; in particular, strategies that incorporate fungi in combination with arthropod predators and parasitoids need to be defined to ensure compatibility and maximize efficacy. Entomopathogenic nematodes (EPNs) in the genera Steinernema and Heterorhabditis are potent MCAs. Substantial progress in research and application of EPNs has been made in the past decade. The number of target pests shown to be susceptible to EPNs has continued to increase. Advancements in this regard primarily have been made in soil habitats where EPNs are shielded from environmental extremes, but progress has also been made in use of nematodes in above-ground habitats owing to the development of improved protective formulations. Progress has also resulted from advancements in nematode production technology using both in vivo and in vitro systems; novel application methods such as distribution of infected host cadavers; and nematode strain improvement via enhancement and stabilization of beneficial traits. Innovative research has also yielded insights into the fundamentals of EPN biology including major advances in genomics, nematode-bacterial symbiont interactions, ecological relationships, and foraging behavior. Additional research is needed to leverage these basic findings toward direct improvements in microbial control

Excitation and Deexcitation of Benzene

This chapter contains sections titled: - Introduction; - The Nature of the Lower Excited States of Benzene; - Transitions Between Lower Energy States; - Excited State Geometry; - The Influence of the Environment on Electronic States; - The S1 ↔ S0 Radiative Transition; - The S1 ↔ Triplet Radiationless Transition; - The S1 → S0 Radiationless Transition; - The T1 → S0 Phosphorescence Transition; - The T1 → S0 Radiationless Transition; - Transitions from Higher (n > 1) Excited States; - Relevant Photochemical Reactions of Excited States of Benzene; - Benzene Excimer; - Conclusioninfo:eu-repo/semantics/publishedVersio

Type 2 diabetes – an autoinflammatory disease driven by metabolic stress

Type 2 diabetes has traditionally been viewed as a metabolic disorder characterised by chronic high glucose levels, insulin resistance, and declining insulin secretion from the pancreas. Modern lifestyle, with abundant nutrient supply and reduced physical activity, has resulted in dramatic increases in the rates of obesity-associated disease conditions, including diabetes. The associated excess of nutrients induces a state of systemic low-grade chronic inflammation that results from production and secretion of inflammatory mediators from the expanded pool of activated adipocytes. Here, we review the mechanisms by which obesity induces adipose tissue dysregulation, detailing the roles of adipose tissue secreted factors and their action upon other cells and tissues central to glucose homeostasis and type 2 diabetes. Furthermore, given the emerging importance of adipokines, cytokines and chemokines in disease progression, we suggest that type 2 diabetes should now be viewed as an autoinflammatory disease, albeit one that is driven by metabolic dysregulation

The scientific impact of the Cambridge Structural Database: a citation-based study

Four groups of the most highly cited scientific articles (46 in total), which either describe the Cambridge Structural Database (CSD) System or report scientific research applications of the CSD, have been selected for citation analysis. The analysis has been carried out to study the scientific importance of crystal structure information made available to the international research community via the CSD or via reviews and research articles that make use of the CSD as a primary information source. Two groups, A and B of ten articles each (A published before 1998, and B published post-1998), are authored by staff of the CCDC, while two further groups, C and D containing ten reviews and 16 research articles, respectively, are authored by external scientific users of CSD information. Citations have been analysed by their number, and in terms of the journals, scientific subject areas and geographical regions from which the citations originate. Between them, the 46 articles have received 44 381 citations with 15 articles cited more than 1000 times. Citations come from a very broad range of journals and subject areas, with chemistry and crystallography being the dominant fields as expected, but with a very significant citation rate from the life sciences, particularly from the USA. In recent years, there has been a major increase in citations arising from south Asia and the Far East, principally from China, India, Malaysia, Pakistan, Japan, Thailand and Taiwan, who together now rival, and sometimes exceed, the citation rates from Europe and the USA. The effect of citations from new journals, particularly Acta Crystallographica Section E: Structure Reports Online, Crystal Growth and Design and CrystEngComm is clearly reflected in the data

Top Ten Tips Palliative Care Clinicians Should Know About Psychedelic-Assisted Therapy in the Context of Serious Illness

Psychedelic-assisted therapy (PAT) is a burgeoning treatment with growing interest across a variety of settings and disciplines. Empirical evidence supports PAT as a novel therapeutic approach that provides safe and effective treatment for people suffering from a variety of diagnoses, including treatment-resistant depression, substance use disorder, and post-traumatic stress disorder. Within the palliative care (PC) field, one-time PAT dosing may lead to sustained reductions in anxiety, depression, and demoralization-symptoms that diminish the quality of life in both seriously ill patients and those at end of life. Despite a well-noted psychedelic renaissance in scholarship and a renewed public interest in the utilization of these medicines, serious illness-specific content to guide PAT applications in hospice and PC clinical settings has been limited. This article offers 10 evidence-informed tips for PC clinicians synthesized through consultation with interdisciplinary and international leading experts in the field with aims to: (1) familiarize PC clinicians and teams with PAT; (2) identify the unique challenges pertaining to this intervention given the current legalities and logistical barriers; (3) discuss therapeutic competencies and considerations for current and future PAT use in PC; and (4) highlight critical approaches to optimize the safety and potential benefits of PAT among patients with serious illness and their caregivers