Many sports balls develop forces that change their motion due to spin, or the Magnus effect. Spin causes the boundary layer separation points to change leading to an asymmetric pressure distribution ...on the ball, and therefore a force. Seams on baseballs can play a similar role without spin. This paper reports the results of instantaneous velocity field measurements of non-spinning baseballs in flight. Two distinct effects of seams are reported. The first is the effect of seams on the front half of the ball where they may promote boundary layer transition. This is common in other sports balls. A second, more important, effect is to promote boundary layer separation over the seams. This only occurs near the center of the ball. Three Reynolds number values that straddle the drag crisis are measured. Various orientations of the seams are studied mapping out a full rotation of the ball. It is reported that the transition and separation points vary from one shot to the next. This is possibly due to subtle differences in baseball construction and orientation, but is more likely because the data represent random instances in a time-varying process. The average differences in separation points on opposite sides of the ball correlate well to previous force measurements on baseballs.
•Foster care youth and controls differ in neural sensitivity to social interactions.•Foster care youth have greater lateral prefrontal response to exclusion.•They also have less neural response to ...inclusion.•Some of these neural patterns are driven by adverse childhood experiences.•Neural patterns are also related to externalizing problems in foster care youth.
Adolescents in foster care may exhibit differential patterns of brain functioning that contribute to their pervasive socioemotional challenges. However, there has been limited investigation of implicated neural processes, particularly in the social domain. Thus, the current study investigated neural responses to exclusionary and inclusionary peer interactions in adolescents in foster-care.
Participants comprised adolescents aged 11–18 years in foster care (N = 69) and a community sample (N = 69). They completed an fMRI adaptation of Cyberball, a virtual ball-throwing paradigm, that included periods of exclusion and over-inclusion. To investigate neural sensitivity to peer social experiences, we quantified neural responses that scaled with consecutive inclusionary and exclusionary interactions (using parametric modulators).
Relative to the community sample, adolescents in foster care exhibited increasing response to consecutive exclusionary events in lateral prefrontal regions and decreasing response to consecutive inclusionary events in the intraparietal sulcus and temporo-occipital cortex. Further, exploratory analyses revealed that dorsolateral prefrontal activation to exclusion was related to externalizing problems, particularly in the foster care sample.
Findings highlight greater neural sensitivity to exclusionary, and lesser sensitivity to inclusionary, peer interactions in adolescents in foster care. Engagement of prefrontal clusters may reflect greater salience and emotion regulatory processes during exclusion, while parietal and temporal clusters may reflect reduced attention and behavioural engagement during inclusion. Thus foster care involvement is associated with broad changes in neural responses during peer interactions, and further these potentially relate to externalizing problems that have been identified in this vulnerable population.
When transplanted into Xenopus oocytes, the nuclei of mammalian somatic cells are reprogrammed to express stem cell genes such as Oct4, Nanog, and Sox2. We now describe an experimental system in ...which the pluripotency genes Sox2 and Oct4 are repressed in retinoic acid-treated ES cells but are reprogrammed up to 100% within 24 h by injection of nuclei into the germinal vesicle (GV) of growing Xenopus oocytes. The isolation of GVs in nonaqueous medium allows the reprogramming of individual injected nuclei to be seen in real time. Analysis using fluorescence recovery after photobleaching shows that nuclear transfer is associated with an increase in linker histone mobility. A simultaneous loss of somatic H1 linker histone and incorporation of the oocyte-specific linker histone B4 precede transcriptional reprogramming. The loss of H1 is not required for gene reprogramming. We demonstrate both by antibody injection experiments and by dominant negative interference that the incorporation of B4 linker histone is required for pluripotency gene reactivation during nuclear reprogramming. We suggest that the binding of oocyte-specific B4 linker histone to chromatin is a key primary event in the reprogramming of somatic nuclei transplanted to amphibian oocytes.
Per- and polyfluoroalkyl substances (PFAS) are widespread, persistent environmental contaminants that have been linked to various health issues. Comprehensive PFAS analysis often relies on ...ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC HRMS) and molecular fragmentation (MS/MS). However, the selection and fragmentation of ions for MS/MS analysis using data-dependent analysis results in only the topmost abundant ions being selected. To overcome these limitations, All Ions fragmentation (AIF) can be used alongside data-dependent analysis. In AIF, ions across the entire m/z range are simultaneously fragmented; hence, precursor–fragment relationships are lost, leading to a high false positive rate. We introduce IonDecon, which filters All Ions data to only those fragments correlating with precursor ions. This software can be used to deconvolute any All Ions files and generates an open source DDA formatted file, which can be used in any downstream nontargeted analysis workflow. In a neat solution, annotation of PFAS standards using IonDecon and All Ions had the exact same false positive rate as when using DDA; this suggests accurate annotation using All Ions and IonDecon. Furthermore, deconvoluted All Ions spectra retained the most abundant peaks also observed in DDA, while filtering out much of the artifact peaks. In complex samples, incorporating AIF and IonDecon into workflows can enhance the MS/MS coverage of PFAS (more than tripling the number of annotations in domestic sewage). Deconvolution in complex samples of All Ions data using IonDecon did retain some false fragments (fragments not observed when using ion selection, which were not isotopes or multimers), and therefore DDA and intelligent acquisition methods should still be acquired when possible alongside All Ions to decrease the false positive rate. Increased coverage of PFAS can inform on the development of regulations to address the entire PFAS problem, including both legacy and newly discovered PFAS.
The components and subprocesses underlying the formation of COPI-coated vesicles at the Golgi are well understood. The coating cascade is initiated after the small GTPase Arf1 is activated by the ...Sec7 domain-containing guanine nucleotide exchange factor GBF1 (Golgi brefeldin A resistant guanine nucleotide exchange factor 1). This causes a conformational shift within Arf1 that facilitates stable association of Arf1 with the membrane, a process required for subsequent recruitment of the COPI coat. Although we have atomic-level knowledge of Arf1 activation by Sec7 domain-containing GEFs, our understanding of the biophysical processes regulating Arf1 and GBF1 dynamics is limited. We used fluorescence recovery after photobleaching data and kinetic Monte Carlo simulation to assess the behavior of Arf1 and GBF1 during COPI vesicle formation in live cells. Our analyses suggest that Arf1 and GBF1 associate with Golgi membranes independently, with an excess of GBF1 relative to Arf1. Furthermore, the GBF1-mediated Arf1 activation is much faster than GBF1 cycling on/off the membrane, suggesting that GBF1 is regulated by processes other than its interactions Arf1. Interestingly, modeling the behavior of the catalytically inactive GBF1/E794K mutant stabilized on the membrane is inconsistent with the formation of a stable complex between it and an endogenous Arf1 and suggests that GBF1/E794K is stabilized on the membrane independently of complex formation.
Dissolved organic compounds in oil sands process affected water (OSPW) are known to be responsible for most of its toxicity to aquatic organisms, but the complexity of this mixture prevents use of ...traditional bottom-up approaches for predicting toxicities of mixtures. Therefore, a top-down approach to predict toxicity of the dissolved organic fraction of OSPW was developed and tested. Accurate masses (i.e., m/z) determined by ultrahigh resolution mass spectrometry in negative and positive ionization modes were used to assign empirical chemical formulas to each chemical species in the mixture. For each chemical species, a predictive measure of lipid accumulation was estimated by stir-bar sorptive extraction (SBSE) to poly(dimethyl)siloxane, or by partitioning to solid-supported lipid membranes (SSLM). A narcosis mode of action was assumed and the target-lipid model was used to estimate potencies of mixtures by assuming strict additivity. A model developed using a combination of the SBSE and SSLM lipid partitioning estimates, whereby the accumulation of chemicals to neutral and polar lipids was explicitly considered, was best for predicting empirical values of LC50 in 96-h acute toxicity tests with embryos of fathead minnow (Pimephales promelas). Model predictions were within 4-fold of observed toxicity for 75% of OSPW samples, and within 8.5-fold for all samples tested, which is comparable to the range of interlaboratory variability for in vivo toxicity testing.
Renal failure is common among patients undergoing liver transplantation. Liver allocation based on the model for end-stage liver disease score has increased the number of recipients who require ...perioperative renal replacement therapy (RRT). Although RRT can be continued intraoperatively, the risks and benefits of intraoperative RRT are not well defined. The aim of this study is to report the intraoperative management of patients with pretransplant renal failure at a transplant center with extremely infrequent utilization of intraoperative RRT.
We performed a retrospective analysis of all adult patients undergoing orthotopic liver or simultaneous liver-kidney (SLK) transplantation between June 2009 and December 2015. Patients were divided into 2 groups based on their need for pretransplant RRT.
A total of 785 patients underwent liver or SLK transplant during the study period. One hundred and seventy-four patients (22.2%) required preoperative dialysis. Only 2 patients required intraoperative RRT. There was no difference in the incidence of acidosis or hyperkalemia between patients who required preoperative dialysis and those who did not.
We describe the successful management of patients undergoing liver or SLK transplantation almost entirely without the need for intraoperative RRT.
Increasing Spanish fluency in the United States likely shapes ethnoracial group boundaries and inequality. We study a key site for group boundary negotiations—the housing market—where Spanish usage ...may represent a key source of information exchange between landlords and prospective renters. Specifically, we examine the use of Spanish in advertisements for online rental housing and its effect on White, Black, and Latinx Americans' residential preferences. Using a corpus of millions of Craigslist rental listings, we show that Spanish listings are concentrated in majority-Latinx neighborhoods with greater proportions of immigrant and Spanish-speaking residents. Furthermore, units that are advertised in Spanish tend be lower priced relative to non-Spanish ads in the same neighborhood. We then use a survey experiment to demonstrate that Spanish usage decreases White, Black, and non-Spanish-speaking Latinx Americans' interest in a housing unit and surrounding neighborhood, whereas Spanish-speaking Latinx respondents are less affected. We discuss these findings in light of past work on neighborhood demographic preferences, segregation, and recent theorizing on within-category inequality.
Purpose
The aim of this study was to evaluate the potential and feasibility of radiomic features extracted from low field strength (0.35 T) magnetic resonance images (MRIs) in predicting treatment ...response for patients with pancreatic cancer undergoing stereotactic body radiotherapy (SBRT).
Methods
Twenty patients with unresected, non‐metastatic pancreatic ductal adenocarcinoma (PDAC) were enrolled, all of whom received neoadjuvant chemotherapy followed by five‐fraction MR‐guided SBRT with a radiation dose range of 33−50 Gy. For each patient, five daily setup scans were acquired from a hybrid 0.35 T MRI/radiotherapy unit. Tumor heterogeneity quantified with radiomic features extracted from the gross tumor volume (GTV) was averaged over the course of treatment. Random forest (RF) and adaptive least absolute shrinkage and selection operator (LASSO) classification models were constructed to identify radiomics features predictive of treatment response. Predictive capability of the top‐performing features was then evaluated using the receiver operating characteristic area under curve (AUC) obtained using leave‐one‐out cross‐validation.
Results
Half of the 20 patients showed response to treatment, defined by tumor regression on histopathology or tumor response on follow‐up dynamic contrast‐enhanced computed tomography (CT). The most predictive features selected by the RF method were GLCM energy and GLSZM gray‐level variance. The RF‐based model achieved an AUC = 0.81 with a 95% confidence interval of 0.594 to 1 The LASSO algorithm selected GLCM energy as the only predictive feature, achieving an AUC = 0.81 with 95% confidence interval of 0.596 to 1.
Conclusion
The findings of this study suggest that radiomic features extracted during MR‐guided SBRT may contain predictive information about response of PDAC patients to treatment. Using the images acquired during treatment of PDAC patients supports continued expansion of radiomic analysis based on low field strength MR images and may hold the potential for providing timely indications of response to treatment.
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