Is an intermediate state populated on the folding pathway of ubiquitin?

AbstractIn the last couple of years, there has been increasing debate as to the presence and role of intermediate states on the folding pathways of several small proteins, including the 76-residue protein ubiquitin. Here, we present detailed kinetic studies to establish whether an intermediate state is ever populated during the folding of this protein. We show that the differences observed in previous studies are attributable to the transient aggregation of the protein during folding. Using a highly soluble construct of ubiquitin, which does not aggregate during folding, we establish the conditions in which an intermediate state is sufficiently stable to be observed by kinetic measurements

Historical documentation of the Allegheny Woodrat (Neotoma magister) in Massachusetts

Although most summaries of the distribution of the Allegheny Woodrat, Neotoma magister, do not include the Commonwealth of Massachusetts, there are two historical reports that lack details of its distribution in Massachusetts. Herein, we review those literature reports and provide details on a specimen from the Berkshire Mountains taken in 1958. No additional observations of woodrats have been documented in Massachusetts over the subsequent 60 years. Recent searching for evidence of woodrats at the Berkshire Mountains site and efforts in the past several decades to locate a population elsewhere in Massachusetts have not been successful. The Allegheny Woodrat historically did occur in Massachusetts and, based on the limited available habitat and the documented patterns of decline in other portions of the Northeast, especially New York, it is almost surely now extirpated from the Commonwealth

Interactions between respiratory oscillators in adult rats

Breathing in mammals is hypothesized to result from the interaction of two distinct oscillators: the preBötzinger Complex (preBötC) driving inspiration and the lateral parafacial region (pFL) driving active expiration. To understand the interactions between these oscillators, we independently altered their excitability in spontaneously breathing vagotomized urethane-anesthetized adult rats. Hyperpolarizing preBötC neurons decreased inspiratory activity and initiated active expiration, ultimately progressing to apnea, i.e., cessation of both inspiration and active expiration. Depolarizing pFL neurons produced active expiration at rest, but not when inspiratory activity was suppressed by hyperpolarizing preBötC neurons. We conclude that in anesthetized adult rats active expiration is driven by the pFL but requires an additional form of network excitation, i.e., ongoing rhythmic preBötC activity sufficient to drive inspiratory motor output or increased chemosensory drive. The organization of this coupled oscillator system, which is essential for life, may have implications for other neural networks that contain multiple rhythm/pattern generators

The contribution of Trichoderma to balancing the costs of plant growth and defense

Trichoderma is a fungal genus of cosmopolitan distribution and high biotechnological value, with several species currently used as biological control agents. Additionally, the enzyme systems of the fungus are widely applied in industry. Species of Trichoderma protect plants against the attack of soil-borne plant pathogens by competing for nutrients and inhibiting or killing plant pathogenic fungi and oomycetes, through the production of antibiotics and/or hydrolytic enzymes. In addition to the role of Trichoderma spp. as biocontrol agents, they have other benefi cial effects on plants, including the stimulation of plant defenses and the promotion of plant growth. In this review, we focus on the complex plant defense signaling network that allows the recognition of fungi as non-hostile microbes, including microbial-associated molecular patterns (MAMPs), damageassociated molecular patterns (DAMPs) and secreted elicitors. We also examine how fungal interactions with plant receptors can activate induced resistance by priming and balancing plant defense and growth responses. Our observations are integrated into a model describing Trichoderma-plant hormone signaling network interactions. [Int Microbiol 2013; 16(2):69-80]Keywords: Trichoderma spp.; plant–Trichoderma symbiosis; Arabidopsis thaliana; phytohormone networking&nbsp

Human Performance Contributions to Safety in Commercial Aviation

In the commercial aviation domain, large volumes of data are collected and analyzed on the failures and errors that result in infrequent incidents and accidents, but in the absence of data on behaviors that contribute to routine successful outcomes, safety management and system design decisions are based on a small sample of non- representative safety data. Analysis of aviation accident data suggests that human error is implicated in up to 80% of accidents, which has been used to justify future visions for aviation in which the roles of human operators are greatly diminished or eliminated in the interest of creating a safer aviation system. However, failure to fully consider the human contributions to successful system performance in civil aviation represents a significant and largely unrecognized risk when making policy decisions about human roles and responsibilities. Opportunities exist to leverage the vast amount of data that has already been collected, or could be easily obtained, to increase our understanding of human contributions to things going right in commercial aviation. The principal focus of this assessment was to identify current gaps and explore methods for identifying human success data generated by the aviation system, from personnel and within the supporting infrastructure

Explanatory Model on Academic Self-Efficacy in Engineering Students: Role of Anxiety, Dysthymia, and Negative Affect

Students in engineering tend to be loners, making interpersonal relationships and mental health issues more likely to arise. The COVID pandemic caused university students to experience anxi-ety and depression, which affected their academic performance and self-esteem. However, stu-dents’ mental health was rarely evaluated after the pandemic, especially engineering students, who showed higher levels of depression than students from other disciplines. The present study aims to establish an explanatory model of academic self-efficacy based on factors related to mental health, such as anxiety, depression, and negative emotions. The method used was quan-titative cross-sectional, and a structural equation modeling was used. A sample of 561 students (54.4% males and 45.6% females) was analyzed. Instruments to measure self-efficacy, negative affect, depression, and anxiety, previously validated and with adequate reliability, were applied. The results showed that a state of anxiety affects academic self-efficacy negatively and directly; depression and negative affect indirectly affect academic self-efficacy mediated by a state of anxiety. These results show that a student with depression problems and a predominance of negative emotions is vulnerable to present anxiety in an academic setting. This anxiety causes his efficacy beliefs to decrease. As a result, he does not feel capable of facing academic challenges