Prevalence and dynamics of ribosomal DNA micro-heterogeneity are linked to population history in two contrasting yeast species

Despite the considerable number and taxonomic breadth of past and current genome sequencing projects, many of which necessarily encompass the ribosomal DNA, detailed information on the prevalence and evolutionary significance of sequence variation in this ubiquitous genomic region are severely lacking. Here, we attempt to address this issue in two closely related yet contrasting yeast species, the baker's yeast Saccharomyces cerevisiae and the wild yeast Saccharomyces paradoxus. By drawing on existing datasets from the Saccharomyces Genome Resequencing Project, we identify a rich seam of ribosomal DNA sequence variation, characterising 1,068 and 970 polymorphisms in 34 S. cerevisiae and 26 S. paradoxus strains respectively. We discover the two species sets exhibit distinct mutational profiles. Furthermore, we show for the first time that unresolved rDNA sequence variation resulting from imperfect concerted evolution of the ribosomal DNA region follows a U-shaped allele frequency distribution in each species, similar to loci that evolve under non-concerted mechanisms but arising through rather different evolutionary processes. Finally, we link differences between the shapes of these allele frequency distributions to the two species' contrasting population histories

From Small Towns to Large Cities: A Comparative Study Looking at the Factors Affecting Homicide Clearance Rates in Two Types of Colorado Geographic Areas

Since the 1960\u27s, there has been a substantial decline in clearance rates of homicides, a finding which has gained little attention from criminological researchers. This article presents a comparative study of homicide clearance in small geographic areas and large cities in Colorado using data from the FBI\u27s Supplemental Homicide Report and the Colorado Bureau of Investigation\u27s Cold Case Database. Using binary logistic regression, homicide clearance rates are predicted based on specific victim and offense characteristics such as weapon and sex, race and age of the victim. The results indicate that while it mattered if a gun was used in a small geographic area, and if the victim was a male in large cities in Colorado, race and age did not differ between the three locations. Having a white victim between the ages of 0 and 23 seemed to significantly predict homicide clearance in all three locations, while the influence of sex and weapon seemed to matter depending on the location

Unraveling the Shift to the Entrepreneurial Economy

A recent literature has emerged providing compelling evidence that a major shift in the organization of the developed economies has been taking place: away from what has been characterized as the managed economy towards the entrepreneurial economy. In particular, the empirical evidence provides consistent support that (1) the role of entrepreneurship has significantly increased, and (2) a positive relationship exists between entrepreneurial activity and economic performance. However, the factors underlying this observed shift have not been identified in a systematic manner. The purpose of this paper is to suggest some of the factors leading to this shift and implications for public policy. In particular, we find that a fundamental catalyst underlying the shift from the managed to the entrepreneurial economy involved the role of technological change. However, we also find that it was not just technological change but rather involved a number of supporting factors, ranging from the demise of the communist system, increased globalization, new competition for multinational firms and higher levels of prosperity. Recognition of the causes of the shift from the managed to the entrepreneurial economy suggests a rethinking of the public policy approach. Rather than the focus of directly and exclusively on promoting startups and SMEs, it may be that the current approach to entrepreneurship policy is misguided. The priority should not be on entrepreneurship policy but rather a more pervasive and encompassing approach, policy consistent with an entrepreneurial economy

Impacts of climate change on plant diseases – opinions and trends

There has been a remarkable scientific output on the topic of how climate change is likely to affect plant diseases in the coming decades. This review addresses the need for review of this burgeoning literature by summarizing opinions of previous reviews and trends in recent studies on the impacts of climate change on plant health. Sudden Oak Death is used as an introductory case study: Californian forests could become even more susceptible to this emerging plant disease, if spring precipitations will be accompanied by warmer temperatures, although climate shifts may also affect the current synchronicity between host cambium activity and pathogen colonization rate. A summary of observed and predicted climate changes, as well as of direct effects of climate change on pathosystems, is provided. Prediction and management of climate change effects on plant health are complicated by indirect effects and the interactions with global change drivers. Uncertainty in models of plant disease development under climate change calls for a diversity of management strategies, from more participatory approaches to interdisciplinary science. Involvement of stakeholders and scientists from outside plant pathology shows the importance of trade-offs, for example in the land-sharing vs. sparing debate. Further research is needed on climate change and plant health in mountain, boreal, Mediterranean and tropical regions, with multiple climate change factors and scenarios (including our responses to it, e.g. the assisted migration of plants), in relation to endophytes, viruses and mycorrhiza, using long-term and large-scale datasets and considering various plant disease control methods

Endophytes vs tree pathogens and pests: can they be used as biological control agents to improve tree health?

Like all other plants, trees are vulnerable to attack by a multitude of pests and pathogens. Current control measures for many of these diseases are limited and relatively ineffective. Several methods, including the use of conventional synthetic agro-chemicals, are employed to reduce the impact of pests and diseases. However, because of mounting concerns about adverse effects on the environment and a variety of economic reasons, this limited management of tree diseases by chemical methods is losing ground. The use of biological control, as a more environmentally friendly alternative, is becoming increasingly popular in plant protection. This can include the deployment of soil inoculants and foliar sprays, but the increased knowledge of microbial ecology in the phytosphere, in particular phylloplane microbes and endophytes, has stimulated new thinking for biocontrol approaches. Endophytes are microbes that live within plant tissues. As such, they hold potential as biocontrol agents against plant diseases because they are able to colonize the same ecological niche favoured by many invading pathogens. However, the development and exploitation of endophytes as biocontrol agents will have to overcome numerous challenges. The optimization and improvement of strategies employed in endophyte research can contribute towards discovering effective and competent biocontrol agents. The impact of environment and plant genotype on selecting potentially beneficial and exploitable endophytes for biocontrol is poorly understood. How endophytes synergise or antagonise one another is also an important factor. This review focusses on recent research addressing the biocontrol of plant diseases and pests using endophytic fungi and bacteria, alongside the challenges and limitations encountered and how these can be overcome. We frame this review in the context of tree pests and diseases, since trees are arguably the most difficult plant species to study, work on and manage, yet they represent one of the most important organisms on Earth

Endophytes vs tree pathogens and pests: can they be used as biological control agents to improve tree health?

Like all other plants, trees are vulnerable to attack by a multitude of pests and pathogens. Current control measures for many of these diseases are limited and relatively ineffective. Several methods, including the use of conventional synthetic agro-chemicals, are employed to reduce the impact of pests and diseases. However, because of mounting concerns about adverse effects on the environment and a variety of economic reasons, this limited management of tree diseases by chemical methods is losing ground. The use of biological control, as a more environmentally friendly alternative, is becoming increasingly popular in plant protection. This can include the deployment of soil inoculants and foliar sprays, but the increased knowledge of microbial ecology in the phytosphere, in particular phylloplane microbes and endophytes, has stimulated new thinking for biocontrol approaches. Endophytes are microbes that live within plant tissues. As such, they hold potential as biocontrol agents against plant diseases because they are able to colonize the same ecological niche favoured by many invading pathogens. However, the development and exploitation of endophytes as biocontrol agents will have to overcome numerous challenges. The optimization and improvement of strategies employed in endophyte research can contribute towards discovering effective and competent biocontrol agents. The impact of environment and plant genotype on selecting potentially beneficial and exploitable endophytes for biocontrol is poorly understood. How endophytes synergise or antagonise one another is also an important factor. This review focusses on recent research addressing the biocontrol of plant diseases and pests using endophytic fungi and bacteria, alongside the challenges and limitations encountered and how these can be overcome. We frame this review in the context of tree pests and diseases, since trees are arguably the most difficult plant species to study, work on and manage, yet they represent one of the most important organisms on Earth

Caspase involvement in autophagy

Caspases are a family of cysteine proteases widely known as the principal mediators of the apoptotic cell death response, but considerably less so as the contributors to the regulation of pathways outside cellular demise. In regards to autophagy, the modulatory roles of caspases have only recently begun to be adequately described. In contrast to apoptosis, autophagy promotes cell survival by providing energy and nutrients through the lysosomal degradation of cytoplasmic constituents. Under basal conditions autophagy and apoptosis cross-regulate each other through an elaborate network of interconnections which also includes the interplay between autophagyrelated proteins (ATGs) and caspases. In this review we focus on the effects of this crosstalk at the cellular level, as we aim to concentrate the main observations from research conducted so far on the fine-tuning of autophagy by caspases. Several members of this protease-family have been found to directly interact with key ATGs involved in different tiers across the autophagic cascade. Therefore, we firstly outline the core mechanism of macroautophagy in brief. In an effort to emphasize the importance of the intricate cross-regulation of ATGs and caspases, we also present examples drawn from Drosophila and plant models regarding the contribution of autophagy to apoptotic cell death during normal development

Evaluation of Tibial Slope on Radiographs in Pediatric Patients With Tibial Spine Fractures: An Age- and Sex-Matched Study

BACKGROUND: A recent study has reported that the radiographic measurement of posterior tibial slope (PTS) is larger in male pediatric patients with tibial spine fractures (TSF) than in controls. However, they found no difference in PTS between female patients and controls. PURPOSE: (1) To identify whether PTS is larger in female pediatric patients with TSF than in female controls and (2) to validate the relationship between PTS and pediatric TSF in male patients. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: After an a priori power analysis, 84 pediatric patients with TSF (50 female patients and 34 male patients) and 84 age- and sex-matched controls were enrolled in this study. Demographic information, including sex, age, and race, was recorded. Skeletal maturity was determined based on the stage of epiphyseal union on knee radiographs. PTS was defined as the angle between a line perpendicular to the longitudinal axis of the tibia and the posterior inclination of the medial tibial plateau on standard knee lateral radiographs. RESULTS: The mean age when the TSF occurred was 11.2 ± 2.7 years for female patients and 12.9 ± 2.5 years for male patients. There was no significant difference in skeletal maturity between female patients and female controls or between male patients and male controls. The mean PTS was not significantly different between female patients (8.8°± 2.8°) and female controls (8.3°± 3.1°) ( CONCLUSION: PTS was not found to be a risk factor for pediatric TSF in female or male patients in this study