Asymmetric Hybridization of Pink (Oncorhynchus gorbuscha) and Chinook (O. tshawytscha) Salmon in the St. Marys River,Michigan

Natural hybridization between pink salmon (Oncorhynchus gorbuscha) and Chinook salmon (O. tshawytscha) has been observed only in the Great Lakes, where both species have been introduced. The direction of hybridization between these species is poorly understood, thus the present study analyzed mitochondrial DNA (mtDNA) to determine whether the maternal parents were pink or Chinook salmon. During annual salmon population surveys on the St. Marys River (1998–2002), fifty putative hybrids of pink salmon and Chinook salmon were identified from meristic, morphometric and color characters. We designed primers to amplify a fragment of the mitochondrial D-loop control region that included both a variable and a control restriction site (BstNI). Polymerase chain reaction, restriction endonuclease digestion and capillary electrophoresis of mtDNA were used in order to identify the maternal parent of each hybrid salmon. In addition, the amplified fragments from the three fish species were sequenced to further verify the results. All hybrid salmon specimens were found to possess Chinook salmon mtDNA, indicating that hybridization between Chinook salmon and pink salmon is asymmetrical and likely unidirectional, occurring only between male pink salmon and female Chinook salmon. Influences contributing to the hybridization of these salmonid species could include limited spatial and temporal segregation of spawners, sexual selection, a limiting number of Chinook males, and/or physiological factors.     

Not all conscientiousness scales change alike: A multimethod, multisample study of age differences in the facets of conscientiousness.

Previous research has shown that traits from the domain of conscientiousness tend to increase with age. However, previous research has not tested whether all aspects of conscientiousness change with age. The present research tests age differences in multiple facets of conscientiousness (industriousness, orderliness, impulse control, reliability, and conventionality) using multiple methods and multiple samples. In a community sample (N = 274) and a representative statewide sample (N = 613) of 18- to 94-year-olds, self-reported industriousness, impulse control, and reliability showed age differences from early adulthood to middle age, whereas orderliness did not. The transition into late adulthood was characterized by increases in impulse control, reliability, and conventionality. In contrast, age differences in observer-rated personality occurred mainly in older adulthood. Age differences held across both ethnicity and levels of socioeconomic status. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fast ultrasound beam prediction for linear and regular two-dimensional arrays

Real-time beam predictions are highly desirable for the patient-specific computations required in ultrasound therapy guidance and treatment planning. To address the longstanding issue of the computational burden associated with calculating the acoustic field in large volumes, we use graphics processing unit (GPU) computing to accelerate the computation of monochromatic pressure fields for therapeutic ultrasound arrays. In our strategy, we start with acceleration of field computations for single rectangular pistons, and then we explore fast calculations for arrays of rectangular pistons. For single-piston calculations, we employ the fast near-field method (FNM) to accurately and efficiently estimate the complex near-field wave patterns for rectangular pistons in homogeneous media. The FNM is compared with the Rayleigh-Sommerfeld method (RSM) for the number of abscissas required in the respective numerical integrations to achieve 1%, 0.1%, and 0.01% accuracy in the field calculations. Next, algorithms are described for accelerated computation of beam patterns for two different ultrasound transducer arrays: regular 1-D linear arrays and regular 2-D linear arrays. For the array types considered, the algorithm is split into two parts: 1) the computation of the field from one piston, and 2) the computation of a piston-array beam pattern based on a pre-computed field from one piston. It is shown that the process of calculating an array beam pattern is equivalent to the convolution of the single-piston field with the complex weights associated with an array of pistons. Our results show that the algorithms for computing monochromatic fields from linear and regularly spaced arrays can benefit greatly from GPU computing hardware, exceeding the performance of an expensive CPU by more than 100 times using an inexpensive GPU board. For a single rectangular piston, the FNM method facilitates volumetric computations with 0.01% accuracy at rates better than 30 ns per field point. Furthermore, we demonstrate array calculation speeds of up to 11.5 X 10(9) field-points per piston per second (0.087 ns per field point per piston) for a 512-piston linear array. Beam volumes containing 256(3) field points are calculated within 1 s for 1-D and 2-D arrays containing 512 and 20(2) pistons, respectively, thus facilitating future real-time thermal dose predictions.     

Protein folds and protein folding

The classification of protein folds is necessarily based on the structural elements that distinguish domains. Classification of protein domains consists of two problems: the partition of structures into domains and the classification of domains into sets of similar structures (or folds). Although similar topologies may arise by convergent evolution, the similarity of their respective folding pathways is unknown. The discovery and the characterization of the majority of protein folds will be followed by a similar enumeration of available protein folding pathways. Consequently, understanding the intricacies of structural domains is necessary to understanding their collective folding pathways. We review the current state of the art in the field of protein domain classification and discuss methods for the systematic and comprehensive study of protein folding across protein fold space via atomistic molecular dynamics simulation. Finally, we discuss our large-scale Dynameomics project, which includes simulations of representatives of all autonomous protein folds.     

Microcellular extrusion of PLA utilizing solid‐state nucleation in the gas‐saturated pellet extrusion process

In this study, we explore the use of solid‐state nucleation in polymer pellets as a means to create microcellular PLA foams in extrusion. This is achieved by using gas‐saturated PLA pellets as input to the extruder. Foam density, bubble size, and bubble density is reported and compared with microcellular foams created in the gas‐injection extrusion process. PLA pellet gas concentrations between 17 and 29 mg CO₂/g PLA was found to produce quality microcellular foams in this process. Gas concentrations within this range were achieved by varying methods that included partial saturation, desorption from full saturation, and blending saturated with unsaturated pellets. This gas concentration window that produced microcellular foams was found to be independent of the saturation and desorption process used to achieve the desired concentration. We further compare the pressure drop and pressure drop rate of the gas‐saturated pellet extrusion process showing that similar foams can be produced at pressures orders of magnitude lower than the alternative gas‐injection extrusion processes. Investigations into extrusion pressures support the hypothesis that the gas‐saturated pellet extrusion process utilizes solid‐state nucleation in the feed section of the extruder to achieve high bubble density foams. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Discovery of Potent Pyrazoline-Based Covalent SARS-CoV-2 Main Protease Inhibitors**

While vaccines and antivirals are now being deployed for the current SARS-CoV-2 pandemic, we require additional antiviral therapeutics to not only effectively combat SARS-CoV-2 and its variants, but also future coronaviruses. All coronaviruses have relatively similar genomes that provide a potential exploitable opening to develop antiviral therapies that will be effective against all coronaviruses. Among the various genes and proteins encoded by all coronaviruses, one particularly “druggable” or relatively easy-to-drug target is the coronavirus Main Protease (3CL^pro or Mpro), an enzyme that is involved in cleaving a long peptide translated by the viral genome into its individual protein components that are then assembled into the virus to enable viral replication in the cell. Inhibiting Mpro with a small-molecule antiviral would effectively stop the ability of the virus to replicate, providing therapeutic benefit. In this study, we have utilized activity-based protein profiling (ABPP)-based chemoproteomic approaches to discover and further optimize cysteine-reactive pyrazoline-based covalent inhibitors for the SARS-CoV-2 Mpro. Structure-guided medicinal chemistry and modular synthesis of di- and tri-substituted pyrazolines bearing either chloroacetamide or vinyl sulfonamide cysteine-reactive warheads enabled the expedient exploration of structure-activity relationships (SAR), yielding nanomolar potency inhibitors against Mpro from not only SARS-CoV-2, but across many other coronaviruses. Our studies highlight promising chemical scaffolds that may contribute to future pan-coronavirus inhibitors.     

A radio-frequency coupling network for heating of citrate-coated gold nanoparticles for cancer therapy: design and analysis

Gold nanoparticles (GNPs) are nontoxic, can be functionalized with ligands, and preferentially accumulate in tumors. We have developed a 13.56-MHz RF-electromagnetic field (RF-EM) delivery system capable of generating high E-field strengths required for noninvasive, noncontact heating of GNPs. The bulk heating and specific heating rates were measured as a function of NP size and concentration. It was found that heating is both size and concentration dependent, with 5 nm particles producing a 50.6 ± 0.2 °C temperature rise in 30 s for 25 μg/mL gold (125 W input). The specific heating rate was also size and concentration dependent, with 5 nm particles producing a specific heating rate of 356 ± 78 kW/g gold at 16 μg/mL (125 W input). Furthermore, we demonstrate that cancer cells incubated with GNPs are killed when exposed to 13.56 MHz RF-EM fields. Compared to cells that were not incubated with GNPs, three out of four RF-treated groups showed a significant enhancement of cell death with GNPs (p<0.05). GNP-enhanced cell killing appears to require temperatures above 50 °C for the experimental parameters used in this study. Transmission electron micrographs show extensive vacuolization with the combination of GNPs and RF treatment.     

Rate analysis of sorption of Ce3+, Sm3+, and Yb3+ ions from aqueous solution using Dowex 50W-X8 as a sorbent in a continuous flow reactor

Kinetic analysis of removal of three rare earth elements metals, Ce³⁺, Sm³⁺, and Yb³⁺ ions from aqueous solutions in a continuous flow fixed bed reactor using Dowex 50W-X8 ion-exchange resin was conducted. The performance of the fixed bed sorption was evaluated using the concept of the sorption breakthrough process. Parameters characteristic of a fixed bed sorption such as breakthrough times, saturation times, critical reactor lengths, and lengths of mass transfer zone were inferred from the metal ion concentration breakthrough curves. The sorption capacity of Dowex 50W-X8 ion-exchange resin for Ce³⁺, Sm³⁺, and Yb³⁺ are 191, 252, and 294 mg/g, respectively. The sorption kinetics were evaluated using a zero-order, first-order and second-order reaction models. The kinetics of the sorption process follows a zero-order model which has not been reported before. The rate constants of sorption using the zero-order kinetic model are obtained. Two different analysis were conducted to identify whether the diffusion is intraparticle or film diffusion. Both analysis confirms that the film diffusion is the controlling mechanism in reactor bed.     

Utility of the MMPI–2-RF (Restructured Form) validity scales in detecting malingering in a criminal forensic setting: A known-groups design.

The current study examined the utility of the recently released Minnesota Multiphasic Personality Inventory–2 Restructured Form (MMPI–2-RF; Ben-Porath & Tellegen, 2008) validity scales to detect feigned psychopathology in a criminal forensic setting. We used a known-groups design with the Structured Interview of Reported Symptoms (SIRS; Rogers, Bagby, & Dickens, 1992) as the external criterion to determine groups of probable malingering versus nonmalingering. A final sample of 125 criminal defendants, who were administered both the SIRS and the MMPI–2-RF during their evaluations, was examined. The results indicated that the two MMPI–2-RF validity scales specifically designed to detect overreported psychopathology, F-r and FP-r, best differentiated between the malingering and nonmalingering groups. These scales added incremental predictive utility to one another in this differentiation. Classification accuracy statistics substantiated the recommended cut scores in the MMPI–2-RF manual (Ben-Porath & Tellegen, 2008) in this forensic setting. Implications for these results in terms of forensic assessment and detection of malingering are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Trained clients as reinforcers of counselor behavior.

Trained undergraduates to discriminate understanding statements from nonunderstanding statements. These ss met with 5 male and 5 female beginning counselors for a series of 3 or 4 interviews. During the interview, clients verbally reinforced each statement they judged to be understanding, while 2 raters judged understanding by electrically marking tape recordings of the interviews. Based on the independent observations of client and 2 raters, beginning counselors were judged as having increased their understanding statements. The experiment indicates that understanding statements made by counselors can be made a function of the number of reinforcing statements emitted by trained clients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)