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BackgroundWrist-worn activity trackers are popular, and an increasing number of these devices are equipped with heart rate (HR) measurement capabilities. However, the validity of HR data obtained from such trackers has not been thoroughly assessed outside the laboratory setting. ObjectiveThis study aimed to investigate the validity of HR measures of a high-cost consumer-based tracker (Polar A370) and a low-cost tracker (Tempo HR) in the laboratory and free-living settings. MethodsParticipants underwent a laboratory-based cycling protocol while wearing the two trackers and the chest-strapped Polar H10, which acted as criterion. Participants also wore the devices throughout the waking hours of the following day during which they were required to conduct at least one 10-min bout of moderate-to-vigorous physical activity (MVPA) to ensure variability in the HR signal. We extracted 10-second values from all devices and time-matched HR data from the trackers with those from the Polar H10. We calculated intraclass correlation coefficients (ICCs), mean absolute errors, and mean absolute percentage errors (MAPEs) between the criterion and the trackers. We constructed decile plots that compared HR data from Tempo HR and Polar A370 with criterion measures across intensity deciles. We investigated how many HR data points within the MVPA zone (≥64% of maximum HR) were detected by the trackers. ResultsOf the 57 people screened, 55 joined the study (mean age 30.5 [SD 9.8] years). Tempo HR showed moderate agreement and large errors (laboratory: ICC 0.51 and MAPE 13.00%; free-living: ICC 0.71 and MAPE 10.20%). Polar A370 showed moderate-to-strong agreement and small errors (laboratory: ICC 0.73 and MAPE 6.40%; free-living: ICC 0.83 and MAPE 7.10%). Decile plots indicated increasing differences between Tempo HR and the criterion as HRs increased. Such trend was less pronounced when considering the Polar A370 HR data. Tempo HR identified 62.13% (1872/3013) and 54.27% (5717/10,535) of all MVPA time points in the laboratory phase and free-living phase, respectively. Polar A370 detected 81.09% (2273/2803) and 83.55% (9323/11,158) of all MVPA time points in the laboratory phase and free-living phase, respectively. ConclusionsHR data from the examined wrist-worn trackers were reasonably accurate in both the settings, with the Polar A370 showing stronger agreement with the Polar H10 and smaller errors. Inaccuracies increased with increasing HRs; this was pronounced for Tempo HR.

In this study, infant vocabulary development was tracked in a multilingual society (Singapore) within a socioeconomically diverse sample. The sample comprised 1316 infants from 17.4 to 27.7 months (669 females, 647 males; 88% Chinese race, 4% Malay, 4% Indian, and 0.004% mixed-race [4% declined to provide race information]). Children varied in English language exposure and socioeconomic status. Analyses focused on identifying demographic predictors of English vocabulary size in multilingually exposed infants. Adaptations of the Macarthur-Bates Communicative Development Inventory for English, Mandarin, and Malay are provided as well as English vocabulary norms that account for variation in English exposure. This manuscript reports the first set of English language norms--calibrated to English exposure--for multilingual infants in a non-Western setting.

COVID-19 has modified numerous aspects of children's social environments. Many children are now spoken to through a mask. There is little empirical evidence attesting to the effects of masked language input on language processing. In addition, not much is known about the effects of clear masks (i.e., transparent face shields) versus opaque masks on language comprehension in children. In the current study, 2-year-old infants were tested on their ability to recognize familiar spoken words in three conditions: words presented with no mask, words presented through a clear mask, and words presented through an opaque mask. Infants were able to recognize familiar words presented without a mask and when hearing words through opaque masks, but not when hearing words through clear masks. Findings suggest that the ability of infants to recover spoken language input through masks varies depending on the surface properties of the mask.

Fenske-Hall molecular orbital computations for Mo3M'S4 cubane-type clusters indicate that their electronic structures are dependent on the nature of M'. Results also show that when M' is a transition metal, it creates metal-metal bonds with the Mo triangle and shares electron density with the Mo3S4 core. Furthermore, high CO stretching frequencies can be attributed to competition between CO pi* orbitals and Mo3 orbitals for electron density.

A study was conducted to determine how electronic structures of transition metal sulfide are associated to their activities as hydrodesulfurization catalysts. Fenske-Hall method was utilized to calculate band structures of Rh2S3 and RuS2 catalysts. Results revealed that the two sulfides did not exhibit metal-metal bonding activity. Instead, both showed metal-sulfur phi bonding and they featured heterogeneous and homogeneous hydrodesulfurization mechanisms which were responsible for their catalytic abilities.

A study was conducted to evaluate the effectiveness of the Fenske-Hall molecular orbital method to a tight-binding band structure formalism for periodic systems. Such a method was utilized to determine the electronic structure of inorganic solids such as transitional metal sulfides and oxide. Results revealed that the two-dimensional MoS2 slabs showed a description of coordinately unsaturated molybdenum and sulfur atoms whose surface bonds were stronger that bulk of Mo-S bonds.

The use of a carbon monoxide gas as a reducing and desulfurizing agent enabled forming metal-metal bonds in a conversion of a {M3S2} aggregate to a {M3S} cluster. This transformation establishes a synthetic relationship between {Pt2MS2} trigonal bipyramidal aggregates and {pt2MS} tetrahedral clusters. The process involves heterometalation, carbonylation and reductive desulfurization and provides a general approach to metal-metal bond formation and the synthesis of triangular heterometallic clusters of platinum.

Complexes with bi- or tridentate coordination modes, mono- and dideprotonated ligands are produced by the controlled reduction of amino acids with nonpolar side chains and salicylaldehyde binding copper(II). The complexes are composed of chiral amino acid derivatives with Cu(II) units that can be utilized as models for biological racemization and transamination reactions of amino acids. The antiferromagnetic coupling between the Cu(II) centers of the complexes is caused by the phenolato-bridged, dimeric structure of the dianionic ligands.

Objective: To investigate and ascertain the source of a nursing home outbreak of gastroenteritis in Melbourne in 1997. Method: A retrospective cohort study. We obtained fecal and food samples and environmental swabs, and reviewed food handling. Results: There were 25 cases, and 21 of these had their meals pureed (liquidised). The relative risk for eating pureed food and becoming ill was 5.8 (95% CI 2.2-15.4). Clostridium perfringens and its enterotoxin was detected in nine fecal samples. Sample of pureed food tested positive for coliforms. Conclusions: This outbreak was cause by C. perfringens contaminating pureed food. Food liquidising provides opportunities for re-contamination of cooked food through the use of contaminated equipment and deficiencies in food handling practices. Pureed foods should be reheated to 70 decrees C after liquidising to inactive pathogens. Implications: Health care facilities need to make specific precautions to manage the special hazards involved in preparing pureed food.

The conversion of Pt2(PPh3)4(mu-S)2 to [Ag{Pt2(PPh3)4(mu-S)2]2+ via [AgPt2(PPh3)5(mu3-S)2]+ and Ag2Pt2Cl2(PPh3)4(mu3-S)2 was analzyed to characterize the sequential growth of heteropolymetallic sulfides. Analysis of the synthetic growth process indicated the presence of an aggregate growth mechanism that was characterized by the stepwise addition of Ag+ and the Pt2 metalloligand. Furthermore, the reaction was characterized by the suquential unfolding and folding of the {PT2S2} butterfly core.

Identities for the electron intracule density I(R) in atoms and molecules are derived within the Hiller–Sucher–Feinberg (HSF) formalism. It is proven that, when applied to arbitrary (exact or approximate) electronic wave functions, these identities produce intracule densities that satisfy a modified condition for the electron coalescence cusp. A corollary of this proof provides a new, simplified derivation of the cusp condition for the exact I(R). An expression for the Hartree–Fock approximation to the HSF electron intracule density that contains only two- and three-electron terms is obtained and its properties are analyzed. A simple scaling of the three-electron contributions in this expression assures integrability of the approximate I(R) and improves its overall accuracy. Numerical tests carried out for the H-, He, Li+, Be2+, Li, and Be systems demonstrate that the application of the scaled HSF-type identity to Hartree–Fock wave functions affords dramatic improvements in the short-range behavior of the electron intracule density. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Examines the vibrational excitation of the reaction hydrogen + lithium[sub2](v, J) → LiH + Li. Summary of trajectory results of the reaction; Factors influencing phase space treatment.