Assessment of amide I spectroscopic maps for a gas-phase peptide using IR-UV double-resonance spectroscopy and density functional theory calculations.

The spectroscopy of amide I vibrations has become a powerful tool for exploring protein structure and dynamics. To help with spectral interpretation, it is often useful to perform molecular dynamics (MD) simulations. To connect spectroscopic experiments to simulations in an efficient manner, several researchers have proposed "maps," which relate observables in classical MD simulations to quantum spectroscopic variables. It can be difficult to discern whether errors in the theoretical results (compared to experiment) arise from inaccuracies in the MD trajectories or in the maps themselves. In this work, we evaluate spectroscopic maps independently from MD simulations by comparing experimental and theoretical spectra for a single conformation of the α-helical model peptide Ac-Phe-(Ala)5-Lys-H(+) in the gas phase. Conformation-specific experimental spectra are obtained for the unlabeled peptide and for several singly and doubly (13)C-labeled variants using infrared-ultraviolet double-resonance spectroscopy, and these spectra are found to be well-modeled by density functional theory (DFT) calculations at the B3LYP/6-31G** level. We then compare DFT results for the deuterated and (13)C(18)O-labeled peptide with those from spectroscopic maps developed and used previously by the Skinner group. We find that the maps are typically accurate to within a few cm(-1) for both frequencies and couplings, having larger errors only for the frequencies of terminal amides.

Erratum: Numerical test of the replica-symmetric Hamiltonian for correlations of the critical state of spin glasses in a field [Phys. Rev. E 105, 054106 (2022)].

This corrects the article DOI: 10.1103/PhysRevE.105.054106.

Critical slowing down exponents of mode coupling theory.

A method is provided to compute the exponent parameter λ yielding the dynamic exponents of critical slowing down in mode coupling theory. It is independent from the dynamic approach and based on the formulation of an effective static field theory. Expressions of λ in terms of third order coefficients of the action expansion or, equivalently, in terms of six point cumulants are provided. Applications are reported to a number of mean-field models: with hard and soft variables and both fully connected and dilute interactions. Comparisons with existing results for the Potts glass model, the random orthogonal model, hard and soft-spin Sherrington-Kirkpatrick, and p-spin models are presented.

Stark coefficients for highly excited rovibrational states of H2O.

Quantum beat spectroscopy is combined with triple-resonance vibrational overtone excitation to measure the Stark coefficients (SCs) of the water molecule for 28 rovibrational levels lying from 27,600 to 41,000 cm(-1). These data provide a stringent test for assessing the accuracy of the available potential energy surfaces (PESs) and dipole moment surfaces (DMSs) of this benchmark molecule in this energy region, which is inaccessible by direct absorption. SCs, calculated using the combination of a high accuracy, spectroscopically determined PES and a recent ab initio DMS, are within the 1% accuracy of available experimental data for levels below 25,000 cm(-1), and within 4.5% for coefficients associated with levels up to 35,000 cm(-1). However, the error in the computed coefficients is over 60% for the very high rovibrational states lying just below the lowest dissociation threshold, due, it seems, to lack of a high accuracy PES in this region. The comparative analysis suggests further steps, which may bring the theoretical predictions closer to the experimental accuracy.

Numerical test of the replica-symmetric Hamiltonian for correlations of the critical state of spin glasses in a field.

A growing body of evidence indicates that the sluggish low-temperature dynamics of glass formers (e.g., supercooled liquids, colloids, or spin glasses) is due to a growing correlation length. Which is the effective field theory that describes these correlations? The natural field theory was drastically simplified by Bray and Roberts in 1980. More than 40 years later, we confirm the tenets of Bray and Roberts's theory by studying the Ising spin glass in an externally applied magnetic field, both in four spatial dimensions (data obtained from the Janus collaboration) and on the Bethe lattice.

Field theory of fluctuations in glasses.

We develop a field-theoretical description of dynamical heterogeneities and fluctuations in supercooled liquids close to the (avoided) MCT singularity. Using quasi-equilibrium arguments, we eliminate time from the description and we completely characterize fluctuations in the beta regime. We identify different sources of fluctuations and show that the most relevant ones are associated to variations of "self-induced disorder" in the initial condition of the dynamics. It follows that heterogeneites can be described through a cubic field theory with an effective random field term. The phenomenon of perturbative dimensional reduction ensues, well known in random field problems, which implies an upper critical dimension of the theory equal to 8. We apply our theory to finite size scaling for mean-field systems and we test its prediction against numerical simulations.

Clinical and Epidemiological Study on Tubercular Uveitis in a Tertiary Eye Care Centre in Italy.

PURPOSE: To describe frequency, clinical characteristics, and visual prognosis of tubercular uveitis (TBU) in a nonendemic country. METHODS: We retrospectively reviewed 3743 charts of patients with endogenous uveitis visited from 2008 to 2018 at a tertiary referral centre in Rome, Italy. We included immunocompetent patients with diagnosis of TBU. Patients were divided in two groups: patients with history of uveitis without a previous diagnosis of TBU (group A) and patients at their first episode of TB uveitis (group B). RESULTS: TBU was diagnosed in 28 (0.75%) out of 3743 patients. Twelve (42.9%) patients came from tuberculosis endemic areas. All patients received specific antitubercular treatment (ATT) and were evaluated for a mean follow-up of 3.2 ± 2.9 years. Group A showed a greater number of ocular complications when compared with group B. ATT was effective in reducing the frequency of recurrences of uveitis in patients of group B. CONCLUSION: Intraocular inflammation can be the first manifestation of tuberculosis. Our data highlight that early diagnosis and specific treatment of TBU may allow to decrease recurrences and to improve visual outcomes.

Nitrogen Fixation by Azotobacter vinelandii Strains Having Deletions in Structural Genes for Nitrogenase.

Phenotypic reversal of Nif(-) mutant strains to Nif(+) under molybdenum-deficient conditions has been cited as evidence that Azotobacter vinelandii possesses two nitrogen fixation systems: the conventional molybdenum-enzyme system and an alternative nitrogen-fixation system. Since explanations other than the existence of an alternative system were possible, deletion strains of A. vinelandii lacking the structural genes for conventional nitrogenase (nifHDK) were constructed. These strains were found to grow in molybdenum-deficient nitrogen-free media, reduce acetylene (at low rates), and incorporate molecular nitrogen labeled with nitrogen-15. Thus it can be concluded that the phenotypic reversal phenomenon cannot be due to altered phenotypic expression of nif mutations under molybdenum-deficient conditions, but is due to the existence of an alternative nitrogen-fixation system in A. vinelandii as originally proposed.

Cavity approximation for graphical models.

We reformulate the cavity approximation (CA), a class of algorithms recently introduced for improving the Bethe approximation estimates of marginals in graphical models. In our formulation, which allows for the treatment of multivalued variables, a further generalization to factor graphs with arbitrary order of interaction factors is explicitly carried out, and a message passing algorithm that implements the first order correction to the Bethe approximation is described. Furthermore, we investigate an implementation of the CA for pairwise interactions. In all cases considered we could confirm that CA[k] with increasing k provides a sequence of approximations of markedly increasing precision. Furthermore, in some cases we could also confirm the general expectation that the approximation of order k , whose computational complexity is O(N(k+1)) has an error that scales as 1/N(k+1) with the size of the system. We discuss the relation between this approach and some recent developments in the field.

Long-term prospective evaluation of offspring of diabetic mothers.

We have suggested that altered maternal metabolism may affect the subsequent anthropometric and neuropsychological development of children who were in utero during disturbances in maternal fuel economy. This study reports the physical growth through 8 yr of age and the neuropsychological development through 4 yr of age in offspring of diabetic mothers (ODM). At birth, 50% of infants had weights greater than 90th percentile for gestational age. By 12 mo, length and weight were similar to the general population. Height remained normal until 7 yr of age, when it became slightly greater than average. After 5 yr of age, relative weight increased dramatically, and by 8 yr of age, half of the ODM had weights greater than 90th percentile. This childhood obesity in ODM is correlated with maternal prepregnant weight and independently with amniotic fluid insulin at 32-38 wk gestation. The Brazelton Neonatal Behavioral Assessment Scale (BNBAS) was administered to 185 newborn ODM. Significant correlations were found between poorer second- and third-trimester glycemic regulation and lower scores in three of four newborn BNBAS dimensions. The Stanford-Binet Intelligence Scale was measured in 102 ODM at 4 yr of age. We found an inverse correlation between childhood IQ and second- and third-trimester maternal lipid metabolism (serum free fatty acids and beta-hydroxybutyrate). This correlation is not explained by adverse perinatal events, socioeconomic status, maternal IQ, ethnicity, or diabetes type. These long-range associations between altered maternal metabolism and childhood growth and development continue to support Freinkel's hypothesis of fuel-mediated teratogenesis.

Long-term effects of the intrauterine environment. The Northwestern University Diabetes in Pregnancy Center.

We sought to test the hypothesis that long-term postnatal development may be modified by metabolic experiences in utero. We enrolled offspring of women with pregestational diabetes (this included type 1 and type 2 diabetes) and gestational diabetes in a prospective study from 1977 to 1983. Fetal beta-cell function was assessed by measurement of amniotic fluid insulin (AFI) concentration at 32-38 weeks' gestation. Postnatally, offspring were seen yearly for neuropsychological testing, measurement of anthropometrics, and modified glucose tolerance testing. Neuropsychological control subjects were followed longitudinally. Additional control subjects had anthropometrics measured once, and a random subset of these had a single oral glucose challenge at 10-16 years. The rates of major neuropsychological disturbances in our cohort did not differ significantly from national estimates. However, aberrant maternal metabolism was associated with poorer intellectual performance and psychomotor development. The macrosomia observed at birth in offspring of diabetic mothers (ODM) resolves by 1 year of age. Obesity recurs in childhood; and by 14-17 years, the mean BMI is 24.6 +/- 5.8 kg/m2 in ODM versus 20.9 +/- 3.4 kg/m2 in control subjects. Obesity in adolescence is associated with sex, mother's weight, and AFI concentration. Impaired glucose tolerance (IGT) is found in 36% of ODM and is also associated with elevated amniotic fluid insulin in utero. In confirmation of our original hypothesis, aberrant maternal metabolism is associated with poorer intellectual and psychomotor development, obesity, and IGT in offspring. Excessive insulin secretion in utero, as assessed by AFI concentration, is a predictor of both obesity and IGT in adolescence. This study is a long-term prospective evaluation of the effects of maternal diabetes on pregnant women and their offspring. In this article, we report the results of the correlations between indexes of maternal and fetal metabolism during pregnancy and the offspring's subsequent physical, metabolic, and psychological development from birth through adolescence.

Usefulness of radionuclide ventriculography in assessment of coronary artery spasm.

Provocative tests that permit detection of coronary artery spasm are widely used in patients with ischemic syndromes. To assess the usefulness of radionuclide ventriculography combined with provocative tests for diagnosis of coronary spasm, the left ventricular (LV) response to exercise, hyperventilation and a cold pressor test was determined in 3 groups. Group I included 10 normal subjects; group II, 49 patients with typical effort angina and fixed obstructive coronary artery disease at catheterization; and group III, 19 patients suspected of having vasospastic angina based on clinical and electrocardiographic findings, each of whom had normal coronary angiographic findings. In group I, LV ejection fraction (EF) increased during hyperventilation and exercise testing in 9 of 10 subjects (90%) and failed to decrease 5% in 9 of 10 subjects (90%) during cold testing. In contrast, while 18 of 49 patients (37%) of group II showed LV dysfunction with cold testing and 8% with hyperventilation, all showed abnormal LV function during exercise. Finally, in group III, LVEF increased during exercise, mimicking the response in normal group, while dysfunction was present in 14 of 19 (74%) during hyperventilation and in 17 of 19 (89%) during cold testing. When results of hyperventilation and cold testing were combined, abnormal responses were present in all patients. Thus, radionuclide ventriculography, when performed in association with 3 forms of stress--exercise, hyperventilation and cold testing--allows accurate identification of patients likely to have coronary spasm.

Nonoperative management of multilevel lumbar disk herniations in an adolescent athlete.

Herniated lumbar nucleus pulposus is rare in the pediatric age-group; for surgically proven cases, the estimated prevalence is between 0.8 and 3.2%. Most of the current literature indicates that herniated nucleus pulposus in pediatric patients differs from that in adult patients in epidemiologic characteristics, clinical manifestations, and frequency of associated neurologic findings. To our knowledge, the current case is the first published report of lumbar disk herniations at three levels in a 15-year-old male adolescent, whose abnormalities were verified by computed tomography and myelography. Most investigators recommend surgical treatment; however, our patient had good results with nonoperative management that consisted of nonsteroid anti-inflammatory drugs, passive extension, lumbar traction, segmental mobilization, and a progressive program of dynamic lumbar stabilization exercises. The patient is now asymptomatic and able to participate in selected limited contact sports and most farm activities; however, contact sports are prohibited for 1 year. If follow-up computed tomographic imaging of the lumbar spine demonstrates no progression of the disk abnormalities and if the patient remains asymptomatic, he could consider participation in contact sports after necessary conditioning.

Injuries in adolescent and preadolescent boys at two large wrestling tournaments.

We evaluated injury patterns at two wrestling tournaments involving 1742 participants, aged 6 to 16 years. The overall injury rate was 12.7%. Injuries requiring withdrawal from the tournament occurred in 4.6% of the participants. Of all participants, 3% sustained an injury in their first match, and 1.1% sustained an injury during their first match that required withdrawal from the tournament. Primary areas of injury were the upper extremity (33%) and the neck and back (24%). Wilcoxon rank-sum tests revealed that increasing age and increasing weight were correlated with injury, whereas multiple logistic regression analysis revealed that only increasing age was correlated with injury. These findings suggest the need for medical supervision at large wrestling tournaments, where it is likely that severe injuries will occur. In addition, older wrestlers and perhaps heavier wrestlers are at an increased risk for injury.

Analysis of the infinity-replica symmetry breaking solution of the Sherrington-Kirkpatrick model.

In this work we analyze the Parisi infinity-replica symmetry breaking solution of the Sherrington-Kirkpatrick model without external field using high order perturbative expansions. The predictions are compared with those obtained from the numerical solution of the infinity-replica symmetry breaking equations, which are solved using a pseudospectral code that allows for very accurate results. With these methods we are able to get more insight into the analytical properties of the solutions. We are also able to determine numerically the end point x(max) of the plateau of q(x) and find that lim(T-->0)x(max)(T)>0.5.

Internal anatomy of the larynx and the spread of cancer.

This project investigated the potential spread of cancer within the larynx by an analysis of the permeability and resistance of the subepithelial spaces. Permeation and diffusion of dye injections in the loose connective tissues below the epithelium was analyzed by histologic preparations in the sagittal plane. The margins of the infusion were identified grossly and microscopically, and the influence of the fibrous, elastic, and muscular components was analyzed with reference to the dispersion of the dyes. A close correlation between laboratory data from normal postmortem larynges and clinical problems of laryngeal cancer was observed in this study.

Comparison of the pick-and-smear and Saccomanno methods for sputum cytologic analysis.

The two methods of preparing sputum specimens for cytologic study, the (fresh) pick-and-smear technique and the (blended) Saccomanno technique, were compared using 249 consecutive specimens. Two slides were prepared for each specimen by each technique. Of the specimens, 103 showed squamous metaplasia, carcinoma in situ or carcinoma. A semiquantitative rating system (0 to 4+) was used to determine the number of diagnostic cells for each method for those 103 cases. More diagnostic cells were found on the Saccomanno preparations (217) than on the fresh preparations (154). There were 121 diagnostic cells in the Saccomanno preparations versus 95 diagnostic cells in the fresh preparations from 63 squamous metaplasias; 7 versus 3 for the preparations from 5 carcinomas in situ; 64 versus 42 from 28 squamous cell carcinomas; 3 versus 1 from 1 large cell undiffernomas; and 12 diagnostic cells in Saccomanno preparations versus 5 in fresh preparations from 3 small cell cancers. Twelve squamous metaplasias, two carcinomas in situ, four squamous carcinomas, one adenocarcinoma and one small cell cancer had no diagnostic cells on the fresh preparations; four squamous metaplasias and one squamous carcinoma had no diagnostic cells on the Saccomanno preparations. More diagnostic information and fewer false-negative results were achieved with the Saccomanno technique.

Laryngeal spaces and lymphatics: current anatomic concepts.

This investigation evaluates the anatomic concepts of individual spaces or compartments within the larynx by isotope and dye diffusion. The authors identified continuity of spaces particularly within the submucosal planes and a relative isolation within the fixed structures resulting from the longitudinal pattern of fibroelastic tissues, muscle bands, and perichondrium. The historical data of anatomic resistance are refuted by the radioisotope patterns of dispersion and the histologic evidence of tissue permeability to the carbon particles. There is little clinical application of the compartment concept to the perimeter of growth and the configuration of extensive endolaryngeal cancers. The internal and extralaryngeal lymphatic network is presented and the regional associations are identified. The normal ipsilateral relationship is distorted by dispersion within the endolarynx supervening the anatomic midline. The effects of lymphatic obstruction caused by regional lymphadenectomy, tumor fixation, and irradiation-infection sequelae are illustrated; these result in widespread bilateral lymphatic nodal terminals. Finally, the evidence suggests that the internal network is modified by external interruption to accommodate an outflow system in continuity with the residual patent lymphatic channels.

Attitudes of undergraduate physical education majors in Brazil toward teaching students with disabilities.

This study assessed the relationship of attitudes of physical education majors in Brazil to specific disabling conditions, i.e., Emotional and Behavioral Disorders, Specific Learning Disabilities, Moderate Mental Retardation, and Orthopedic Impairment. This study also identified which selected teachers' attributes, i.e., age, sex, years of teaching, course work in adapted physical education, course work in special education, years teaching students with disabilities, quality of teaching experience, and perceived competence were related to favorable attitudes. Analysis showed no significant differences toward teaching students with these disabilities. Simultaneous multiple regression procedure also showed perceived competence was the only statistically significant predictor of attitudes toward teaching such students.

Using RICE for Injury Relief.

Few athletes, whether serious or casual, completely avoid injuries to soft body tissues like muscles (strains) or ligaments (sprains). Though painful, minor sprains or strains often don't require a trip to the doctor's office. What, then, is a mildly injured body to do to get on the right track to healing?