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Two genetically engineered, recombinant versions of native barnacle troponin C (TnC) (BTnC2) were created from the bacterially expressed, recombinant, wild-type BTnC (BTnCWT) to investigate the role of the Ca2+-specific sites in force regulation. The mutant BTnC4– contains a single amino acid mutation in site IV which results in the inactivation of site IV Ca2+ binding; the mutant BTnCTrunc lacks the last 11 amino acids of the C-terminal, and hence most of site IV. Both mutant proteins, which retain an active site II, bind to native TnC-depleted myofibrillar bundles and restore approximately 40% of the tension-generating capacity, about half that seen with purified native BTnC1 or BTnC2. This observation implies that the Mg2+-dependent interaction with troponin I (TnI) is at a location on TnC other than the C-terminal Ca2+-binding sites of BTnC2. Replacement with BTnCTrunc increases the sensitivity of the myofibrillar bundle to changes in ionic strength. Decreasing the ionic strength from 0.15 to 0.075 M increased force by 34%, a value much greater that the 8% increase seen in control bundles or bundles substituted with BTnC4–. These findings implicate TnC in determining this fibre characteristic, although this cannot be simply due to the alteration in the numbers of Ca2+ ions bound by the troponin complex since both BTnC4– and BTnCTrunc bind only 1 mol Ca2+/mol protein [ABSTRACT FROM AUTHOR]

If S and C denote, respectively, the symmetric group and inverse semigroup on n symbols, then S ⊂C and a semigroup T⊂C is S -normal if α Tα ⊂ Tfor every α∈ S . The S -normal semigroups are classified. [ABSTRACT FROM AUTHOR]

The war in Ukraine significantly impacts the mental health and well-being of its youth. Like other communities affected by war, Ukraine's youth are at risk of developing psychopathological symptoms, and there is a shortage of mental health and psychosocial support services to address this. Resilience-building initiatives present an alternative approach to supporting the well-being of young people by promoting protective processes to enhance the likelihood of positive development in the context of adversity. Emerging research findings suggest that young people themselves can serve as powerful facilitators of such initiatives with one another. Yet, evidence about culturally and contextually relevant protective processes is needed to guide such interventions, especially among young people experiencing the war and working to boost resilience within their communities. In this study, we identified key protective processes Ukrainian youth depend on as they adapt to the conflict while also preparing to implement a resilience-building intervention as a facilitator. Through thematic analysis of transcripts of three training sessions with Ukrainian youth ( n  = 15, 100% female; aged 18-22), we identified the following themes: positive thinking, sense of control, emotion awareness and regulation, close personal relationships, and community support. Findings also highlighted the cultural and contextual nuance of these protective processes, as well as individual differences in the ways they co-occurred and manifested within each youth. Results have implications for developing tailored yet flexible resilience-building interventions that can be delivered by lay people, including youth with their peers, in Ukraine and other cultures and contexts., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Giordano, Lipscomb, Jefferies, Kwon and Giammarchi.)

Introduction: American Indian and Alaska Native (AI/AN) children possess numerous cultural assets, yet higher exposures to neighborhood risks (e.g., lack of housing, crime) may present barriers to healthy cognitive development, including executive function (EF). Cultural socialization may promote resilience and support children's early cognition, but this has not been adequately studied. The present study examined the effects of neighborhood risk and cultural socialization on EF for AI/AN preschool children., Method: Parents/caregivers of 768 AI/AN preschoolers from the 2015 AI/AN Head Start Family and Community Experiences (FACES) Study rated neighborhood risk via two scales: "Neighborhood Problems" and "Environmental Conditions," and cultural socialization practices via two scales: cultural activities and tribal language activities. Children's EF was measured directly using the Pencil Tap Task and the Leiter-R attention subscale., Results: Families perceived neighborhood risks as relatively low, and overall risk did not predict children's EF. However, higher average language socialization was significantly related to higher EF, as were two specific language activities (encouraging children to learn their tribal language, making sure children heard their tribal language) and two cultural activities (playing AI/AN games, participating in tribal ceremonies), controlling for neighborhood risk., Discussion: Findings suggest some aspects of cultural socialization may promote resilience among AI/AN preschoolers by supporting early EF. Mechanisms may include increased spiritual, social, and cultural connections, and practice with EF skills during cultural games. Future research should partner with AI/AN communities to investigate culturally grounded EF interventions and reevaluate measures of neighborhood risk to promote resilience and connectedness for AI/AN children., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Merculief, Lipscomb, McClelland, Geldhof and Tsethlikai.)

Youth in foster care experience major deficits on standardized measures of academic functioning, are at high risk of academic failure, and are more likely than their non-foster peers to be disciplined at school. School discipline-related problems increase risk of problematic educational and behavioral outcomes including dropping out of school, repeating a grade, and engagement in delinquent and criminal behavior. Identifying which youth are at greatest risk for experiencing school discipline is needed in order to improve the educational experiences of youth in foster care. The current investigation examined the effects of youth and contextual characteristics on school discipline events among 315 youth in foster care. Results revealed that being male, in a higher-grade, and a student of color, living apart from one's sibling, and school mobility significantly predicted discipline events. An additional statistical model divided youth into groups based on race, sex, and disability status taking into account the multiple identities youth have. These results suggest that gender, race, and disability status cumulatively inform school discipline experienced among youth in foster care., Competing Interests: Declarations of interest None.

Purpose: The purpose of this article was to examine specific linkages between early visual-motor integration skills and executive function, as well as between early object manipulation skills and social behaviors in the classroom during the preschool year., Method: Ninety-two children aged 3 to 5 years old (M age  = 4.31 years) were recruited to participate. Comprehensive measures of visual-motor integration skills, object manipulation skills, executive function, and social behaviors were administered in the fall and spring of the preschool year., Results: Our findings indicated that children who had better visual-motor integration skills in the fall had better executive function scores (B = 0.47 [0.20], p < .05, β = .27) in the spring of the preschool year after controlling for age, gender, Head Start status, and site location, but not after controlling for children's baseline levels of executive function. In addition, children who demonstrated better object manipulation skills in the fall showed significantly stronger social behavior in their classrooms (as rated by teachers) in the spring, including more self-control (B - 0.03 [0.00], p < .05, β = .40), more cooperation (B = 0.02 [0.01], p < .05, β = .28), and less externalizing/hyperactivity (B = - 0.02 [0.01], p < .05, β = - .28) after controlling for social behavior in the fall and other covariates., Conclusion: Children's visual-motor integration and object manipulation skills in the fall have modest to moderate relations with executive function and social behaviors later in the preschool year. These findings have implications for early learning initiatives and school readiness.

Silicone wristbands can be used as passive sampling tools for measuring personal environmental exposure to organic compounds. Due to the lightweight and simple design, the wristband may be a useful technique for measuring children's exposure. In this study, we tested the stability of flame retardant compounds in silicone wristbands and developed an analytical approach for measuring 41 flame retardants in the silicone wristband in order to evaluate exposure to these compounds in preschool-aged children. To evaluate the robustness of using wristbands to measure flame retardants, we evaluated the stability of 3 polybrominated diphenyl ethers (BDEs), and 2 organophosphate flame retardants (OPFRs) in wristbands over 84 days and did not find any evidence of significant loss over time at either 4 or -20°C (p>0.16). We recruited a cohort of 92 preschool aged children in Oregon to wear the wristband for 7 days in order to characterize children's acceptance of the technology, and to characterize their exposure to flame retardants. Seventy-seven parents returned the wristbands for analysis of 35 BDEs, 4 OPFRs, and 2 other brominated flame retardants although 5 were excluded from the exposure assessment due to protocol deviations (n=72). A total of 20 compounds were detected above the limit of quantitation, and 11 compounds including 4 OPFRs and 7 BDEs were detected in over 60% of the samples. Children's gender, age, race, recruitment site, and family context were not significantly associated with returning wristbands or compliance with protocols. Comparisons between flame retardant data and socio-demographic information revealed significant differences in total exposures to both ΣBDEs and ΣOPFRs based on age of house, vacuuming frequency, and family context. These results demonstrate that preschool children in Oregon are exposed to BDEs that are no longer being produced in the United States and to OPFRs that have been used as an alternative to polybrominated compounds. Silicone wristbands were well tolerated by young children and were useful for characterizing personal exposure to flame retardants that were not bound to particulate matter., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Distal arthrogryposes (DAs) are a group of disorders characterized by congenital contractures of distal limbs without overt neurological or muscle disease. Unexpectedly, mutations in genes encoding the fast skeletal muscle regulatory proteins troponin T (TnT), troponin I (TnI), and beta-tropomyosin (beta-TM) have been shown to cause autosomal dominant DA. We tested how these mutations affect contractile function by comparing wild-type (WT) and mutant proteins in actomyosin ATPase assays and in troponin-replaced rabbit psoas fibers. We have analyzed all four reported mutants: Arg63His TnT, Arg91Gly beta-TM, Arg174Gln TnI, and a TnI truncation mutant (Arg156ter). Thin filaments, reconstituted using actin and WT troponin and beta-TM, activated myosin subfragment-1 ATPase in a calcium-dependent, cooperative manner. Thin filaments containing either a troponin or beta-TM DA mutant produced significantly enhanced ATPase rates at all calcium concentrations without alternating calcium-sensitivity or cooperativity. In troponin-exchanged skinned fibers, each mutant caused a significant increase in Ca2+ sensitivity, and Arg156ter TnI generated significantly higher maximum force. Arg91Gly beta-TM was found to have a lower actin affinity than WT and form a less stable coiled coil. We propose the mutations cause increased contractility of developing fast-twitch skeletal muscles, thus causing muscle contractures and the development of the observed limb deformities.

We recently reported a dilated cardiomyopathy (DCM) causing mutation in a novel disease gene, TNNC1, which encodes cardiac troponin C (TnC). We have determined how this mutation, Gly159Asp, affects contractile regulation when incorporated into muscle fibres. Endogenous troponin in rabbit skinned psoas fibres was partially replaced by recombinant human cardiac troponin containing either wild-type or Gly159Asp TnC. We measured both the force-pCa relationship of these fibres and the activation rate using the caged-Ca(2+) compound nitrophenyl-EGTA. Gly159Asp TnC had no significant effect on either the Ca(2+) sensitivity or cooperativity of force generation when compared to wild type. However, the mutation caused a highly significant (ca. 50%) decrease in the rate of activation. This study shows that whilst not affecting the force-pCa relationship, the mutation Gly159Asp causes a significant decrease in the rate of force production and a change in the relationship between the rate of force production and generated force. In vivo, this mutation may cause both a slowing of force generation and reduction in total systolic force. This represents a novel mechanism by which a cardiomyopathy-causing mutation can affect contractility.

Percussionists inadvertently use visual information to strategically manipulate audience perception of note duration. Videos of long (L) and short (S) notes performed by a world-renowned percussionist were separated into visual (Lv, Sv) and auditory (La, Sa) components. Visual components contained only the gesture used to perform the note, auditory components the acoustic note itself. Audio and visual components were then crossed to create realistic musical stimuli. Participants were informed of the mismatch, and asked to rate note duration of these audio-visual pairs based on sound alone. Ratings varied based on visual (Lv versus Sv), but not auditory (La versus Sa) components. Therefore while longer gestures do not make longer notes, longer gestures make longer sounding notes through the integration of sensory information. This finding contradicts previous research showing that audition dominates temporal tasks such as duration judgment.

The effects of the cardiotonic potentiator EMD 57033 on different TnC (troponin C) isoforms were investigated. Endogenous skeletal TnC was extracted from glycerinated, permeabilized rabbit psoas fibres and replaced with either purified native rabbit psoas TnC (fast TnC) or human recombinant cTnC (cardiac TnC) (3 mg/ml in relaxing solution for 30 min). In both conditions, 10 microM EMD 57033 increased maximal calcium-activated force (Pmax) and gave a leftward shift in the pCa-tension curve. With cTnC, the increase in Pmax was much greater (228%) compared with the effect seen for fast TnC (137%), which was the same as that in unextracted control fibres. When the whole troponin was replaced rather than just TnC, the effects of EMD 57033 on fibres replaced with cTn were the same as with the cTnC subunit alone, except that the force at low Ca2+ concentrations was not increased as much. If TnC was only partially extracted, it was found that the degree of extraction did not influence the effect of EMD 57033, except when force was decreased to below 10% of the pre-extraction Pmax. Dynamic stiffness was not altered by EMD 57033 in any of the preparations. The rate of tension recovery following a release-restretch method (ktr) was decreased by EMD 57033. We conclude that EMD 57033 acts by a rate-modulating effect, and that the quantitative response of this effect is dependent on the TnC isoform present.

The effect of manganese doping on the free radical generation rate, free radical scavenging and UVA absorption properties of micronised sunscreen grade titania has been studied with respect to enhancement of the UVA photostability of test sunscreen formulations containing the organic UVA absorber Parsol 1789. Manganese doping has been shown to increase the UVA:UVB absorption ratio of titania, reduce free radical generation rates by over 90%, and provide free radical scavenging behaviour. Adding manganese-doped titania to a test formulation incorporating Parsol 1789 shows that manganese doping increases UVA attenuation stability by up to 3 times the amount achieved by comparable commercial undoped titania materials. HPLC data shows this to be related to an improved stabilisation of the organic sunscreen components. Manganese doped titania shows improved efficacy over undoped titania in sunscreen formulations containing organic UV absorbers.

Intussusception, the telescoping of one segment of bowel onto an adjacent segment, is uncommon in adults in the United States. This is in contrast to intussusception in the tropics, where most cases occur in adults with GI infections. HIV-infected patients are at high risk for conditions that predispose to intussusception, namely tumors and infections of the GI system. We describe a case of intussusception in an adult patient with AIDS and review the pertinent clinical and diagnostic features of this condition.

Mutagenesis studies on conserved histidine residues identified as possible metal binding ligands in clavaminic acid synthase isozyme 2 were consistent with His-145 and His-280 acting as iron ligands, in support of crystallographic and previous mutagenesis studies. Mutagenesis of the four cysteines and a glutamine residue, conserved in both clavaminic acid synthase isozymes 1 and 2, demonstrated that none of these residues is essential for activity., (Copyright 2000 Academic Press.)

Background & Aims: The use of nurse endoscopists to perform flexible sigmoidoscopy is expanding, increasing the availability of colorectal cancer screening. However, the effectiveness of this practice has not been studied in randomized trials. The aim of this trial was to examine the miss rate of polyps, the depth of sigmoidoscope insertion, and the incidence of complications during flexible sigmoidoscopy performed by nurse endoscopists and by gastroenterologists., Methods: Three hundred twenty-eight patients were randomized to undergo screening flexible sigmoidoscopy performed by a nurse endoscopist or by a gastroenterologist. Frequency of missed polyps was determined by repeat sigmoidoscopy, performed by a gastroenterologist blinded to the identity of the first endoscopist. Multiple logistic regression analysis identified characteristics associated with missed polyps., Results: Gastroenterologists and nurse endoscopists had equivalent miss rates for adenomatous polyps (20% vs. 21%, respectively; P = 0.91). No complications occurred in any patient. Gastroenterologists inserted the sigmoidoscope further than nurse endoscopists (61 vs. 55 cm, respectively; P < 0.00001). Polyp location in the descending colon (odds ratio, 4.1; 95% confidence interval, 1.7-10.3) was highly associated with missed polyps., Conclusions: No differences in detection of adenomatous polyps or frequency of complications were found. These data suggest that experienced nurse endoscopists may perform screening flexible sigmoidoscopy as safely and as effectively as gastroenterologists.

240 university students were given The Cognitive Laterality Battery as well as a questionnaire, the answers to which were used to identify those who had experienced an "Old Hag Attack." This refers to a hypnagogic sleep disorder in which there is paralysis and, quite often, terrifying hallucinations. Those suffering from this disorder showed a statistically significantly different profile of scores from normal subjects on The Cognitive Laterality Battery. The implications of this finding for existing theories concerning "Old Hag Attacks" are discussed.

240 undergraduates were shown 50 color slides of paintings representing ten areas of subject matter and five levels of realism. The subjects rated from 1 to 9 their liking of each painting and then took the Cognitive Laterality Battery. Individuals with clear preference for realism formed one group and those showing clear preference for abstraction formed a second. A multivariate analysis of variance for subjects' Cognitive Laterality Battery scores showed a significant interaction, which may be interpreted as supporting the idea that there is a possible neuropsychological basis for the realism-abstraction preference dimension in aesthetics.

A case of a 1970s methadone clinic is presented within the context of a theory of family dynamics which includes a "perverse triangle." The study of the clinic, its clients, and their families reveals a number of pervasive conflicts and covert coalitions. In the clinic, clients and paraprofessionals combine to undercut professionals and limit the effects of any meaningful treatment. Nontherapeutic alliances, first experienced in the family of the addict, are replicated not only in the clinic but in the treatment system as a whole. The effects of these pathogenic relationships, at any organizational level, are to inhibit the maturation of the addict.