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The aim of this investigation was to study castor, canola, and sesame vegetable oils in order to evaluate their potential use as lubricants in steel mechanical components. For this purpose, densities of each oil were evaluated using the pycnometer method, as well as their dynamic viscosities through a Brookfield DV-II rotational viscometer. Both properties were evaluated at temperatures of 25, 40 and 100 °C. Additionally, viscosity indexes were determined according to ASTM D 2270. These rheological properties were used to estimate the lubrication regime considering parameters of real contact conditions in mechanical components. Friction and wear analyses were carried out to investigate the behaviour of the vegetable oil as lubricants. Such tests were carried out at room temperature on a CSM tribometer with pin-on-disk configuration by using castor, canola and sesame oils as lubricants. AISI 4140 hardened steel against AISI 100Cr6 steel pin was used as a mechanical component. From the rheological study, it was observed that canola and sesame oils behave as dilatant fluids at the evaluated temperatures, while castor oil behaves like a Newtonian fluid at 25 and 40 °C. Castor oil showed the highest density value among oils studied, but it also exhibited the lowest value of viscosity index (271). Contrarily, sesame oil was the least dense, but it exhibited the highest viscosity index (545). On the other hand, the lubrication regime study showed that by using castor oil as a lubricant in the mechanical component (4140/100Cr6), the system worked in a mixed lubrication regime while by using canola and sesame oils the system operated in boundary lubrication conditions. Finally, the kinetic friction coefficients were different for each lubricant obtaining the lowest value with castor oil while the highest value of friction coefficient was exhibited by the sesame oil lubricant.
Identifying risk factors of individuals in a clinical-high-risk state for psychosis are vital to prevention and early intervention efforts. Among prodromal abnormalities, cognitive functioning has shown intermediate levels of impairment in CHR relative to first-episode psychosis and healthy controls, highlighting a potential role as a risk factor for transition to psychosis and other negative clinical outcomes. The current study used the AX-CPT, a brief 15-min computerized task, to determine whether cognitive control impairments in CHR at baseline could predict clinical status at 12-month follow-up.
Baseline AX-CPT data were obtained from 117 CHR individuals participating in two studies, the Early Detection, Intervention, and Prevention of Psychosis Program (EDIPPP) and the Understanding Early Psychosis Programs (EP) and used to predict clinical status at 12-month follow-up. At 12 months, 19 individuals converted to a first episode of psychosis (CHR-C), 52 remitted (CHR-R), and 46 had persistent sub-threshold symptoms (CHR-P). Binary logistic regression and multinomial logistic regression were used to test prediction models.
Baseline AX-CPT performance (d-prime context) was less impaired in CHR-R compared to CHR-P and CHR-C patient groups. AX-CPT predictive validity was robust (0.723) for discriminating converters v. non-converters, and even greater (0.771) when predicting CHR three subgroups.
These longitudinal outcome data indicate that cognitive control deficits as measured by AX-CPT d-prime context are a strong predictor of clinical outcome in CHR individuals. The AX-CPT is brief, easily implemented and cost-effective measure that may be valuable for large-scale prediction efforts.
What are the effects of wearable police cameras on perceptions of the police? In this study, we report causal estimates from a crossover randomized controlled trial in Uruguay on the effects of use of body-worn cameras by traffic police on the perceptions of legitimacy and satisfaction by drivers ticketed for traffic violations. We pay particular attention to the effects on procedural justice—that is, perceptions of the fairness of the interactions between officers and drivers—without neglecting other features of legitimacy (i.e., effectiveness, distributive justice, and lawfulness). With the exception of lawfulness, wearable surveillance apparatuses showed improvements across all dimensions of legitimacy compared to control conditions, with medium to large effect sizes. The overall satisfaction from the police-public interaction was significantly higher when officers used body-worn cameras. These findings suggest that wearable surveillance technology can lead to enhanced perceptions of legitimacy across multiple dimensions, not just increased efficiency, as well as the perceived overall quality of police-public interaction.
This research communication addresses the hypothesis that in dual-purpose goats, exposure to 1 h of extra-light given from 16 to 17 h after dawn (pulse of light) in winter stimulates milk yield. One group of goats was maintained under natural short photoperiod (natural day; ND (n = 7)). Another group of lactating females was submitted to an artificial long-day photoperiod consisting of 16 h light and 8 h darkness (long days; LD (n = 7)). A third group of females received one single hour of extra-light 16 h after the fixed dawn (pulse of light; PL (n = 6)). Goats from LD and PL yielded 30% more milk than goats from ND. Mean percentages of fat, protein and lactose contents in milk did not differ between the 3 groups at any stage of lactation, but these components in grams/day were higher in goats from PL than in the others two groups within the first 45 d of lactation. In conclusion, dual-purpose lactating goats that started their lactation during natural short days, the daily exposition to a 1-h pulse of light is sufficient to stimulate milk yield compared to females maintained under natural short photoperiod.
Smallflower umbrella sedge is a prolific C3 weed commonly found in rice fields in 47 countries. The increasing infestation of herbicide-resistant smallflower umbrella sedge populations threatens rice production. Our objectives for this study were to characterize thermal requirements for germination of smallflower umbrella sedge seeds from rice fields in California and to parameterize a population thermal-time model for smallflower umbrella sedge germination. Because the use of modeling techniques is hampered by the lack of thermal-time model parameters for smallflower umbrella sedge seed germination, trials were carried out by placing field-collected seeds in a thermogradient table set at constant temperatures of 11.7 to 41.7 C. Germination was assessed daily for 30 d, and the whole experiment was repeated a month later. Using probit regression analysis, thermal time to median germination [θT(50)], base temperature for germination (Tb), and SD of thermal times for germination [σθT(50)] were estimated from germination data, and model parameters were derived using the Solver tool in Microsoft Excel®. Germination rates increased linearly below the estimated optimum temperatures of 33.5 to 36 C. Estimated Tb averaged 16.7 C, whereas θT(50) equaled 17.1 degree-days and σθT(50) was only 0.1 degree-day. The estimated Tb for smallflower umbrella sedge is remarkably higher than that of japonica and indica types of rice, as well as Tb of important weeds in the Echinochloa complex. Relative to the latter, smallflower umbrella sedge has lower thermal-time requirements to germination and greater germination synchronicity. However, it would also initiate germination much later because of its higher Tb, given low soil temperatures early in the rice growing season in California. When integrated into weed growth models, these results might help optimize the timing and efficacy of smallflower umbrella sedge control measures.
Inadequate protein quality may be a risk factor for poor growth. To examine the effect of a macronutrient–micronutrient supplement KOKO Plus (KP), provided to infants from 6 to 18 months of age, on linear growth, a single-blind cluster-randomised study was implemented in Ghana. A total of thirty-eight communities were randomly allocated to receive KP (fourteen communities, n 322), a micronutrient powder (MN, thirteen communities, n 329) and nutrition education (NE, eleven communities, n 319). A comparison group was followed cross-sectionally (n 303). Supplement delivery and morbidity were measured weekly and anthropometry monthly. NE education was provided monthly. Baseline, midline and endline measurements at 6, 12 and 18 months included venous blood draws, diet, anthropometry, morbidity, food security and socio-economics. Length-for-age Z-score (LAZ) was the primary outcome. Analyses were intent-to-treat using mixed-effects regressions adjusted for clustering, sex, age and baseline. No differences existed in mean LAZ scores at endline (−1·219 (sd 0·06) KP, −1·211 (sd 0·03) MN, −1·266 (sd 0·03) NE). Acute infection prevalence was lower in the KP than NE group (P = 0·043). Mean serum Hb was higher in KP infants free from acute infection (114·02 (sd 1·87) g/l) than MN (107·8 (sd 2·5) g/l; P = 0·047) and NE (108·8 (sd 0·99) g/l; P = 0·051). Compliance was 84·9 % (KP) and 87·2 % (MN) but delivery 60 %. Adjusting for delivery and compliance, LAZ score at endline was significantly higher in the KP v. MN group (+0·2 LAZ; P = 0·026). A macro- and micronutrient-fortified supplement KP reduced acute infection, improved Hb and demonstrated a dose–response effect on LAZ adjusting consumption for delivery.
Hermaphroditism is thought to be an advantageous strategy common in marine molluscs that exhibit simultaneous, sequential or alternating hermaphroditism. Several species of patellid limpets have previously been shown to be protandrous hermaphrodites. The present study aimed to confirm whether this phenomenon occurs in Patella piperata. Transitional forms of simultaneous protandrous hermaphroditism were found in intermediate size classes of P. piperata, in Madeira (North-eastern Atlantic). Sequential hermaphroditism was confirmed after histological analysis. The overall sex-ratio was biased towards females but approached similar proportions in the larger size classes. Analysis of size at sex change showed that at a shell length of 36 mm 50% of the population probably have changed sex. The results reported confirm the occurrence of sequential hermaphroditism. These findings are of utmost importance to the understanding of the reproductive biology of this species with direct effect on management and conservation of this traditionally harvested limpet.
Species distribution models (SDMs) are statistical tools used to develop continuous predictions of species occurrence. ‘Integrated SDMs’ (ISDMs) are an elaboration of this approach with potential advantages that allow for the dual use of opportunistically collected presence-only data and site-occupancy data from planned surveys. These models also account for survey bias and imperfect detection through the use of a hierarchical modelling framework that separately estimates the species–environment response and detection process. This is particularly helpful for conservation applications and predictions for rare species, where data are often limited and prediction errors may have significant management consequences. Despite this potential importance, ISDMs remain largely untested under a variety of scenarios. We performed an exploration of key modelling decisions and assumptions on an ISDM using the endangered Baird’s tapir (Tapirus bairdii) as a test species. We found that site area had the strongest effect on the magnitude of population estimates and underlying intensity surface and was driven by estimates of model intercepts. Selecting a site area that accounted for the individual movements of the species within an average home range led to population estimates that coincided with expert estimates. ISDMs that do not account for the individual movements of species will likely lead to less accurate estimates of species intensity (number of individuals per unit area) and thus overall population estimates. This bias could be severe and highly detrimental to conservation actions if uninformed ISDMs are used to estimate global populations of threatened and data-deficient species, particularly those that lack natural history and movement information. However, the ISDM was consistently the most accurate model compared to other approaches, which demonstrates the importance of this new modelling framework and the ability to combine opportunistic data with systematic survey data. Thus, we recommend researchers use ISDMs with conservative movement information when estimating population sizes of rare and data-deficient species. ISDMs could be improved by using a similar parameterization to spatial capture–recapture models that explicitly incorporate animal movement as a model parameter, which would further remove the need for spatial subsampling prior to implementation.
This study analyzes the relationship between the two intrapersonal perfectionism dimensions (i.e., Self-Oriented Perfectionism-Critical, SOP-C, and Self-Oriented Perfectionism-Strivings, SOP-S) and the components of aggressive behavior (cognitive, emotional and motor) in a sample of 804 (48.3% females) Spanish students between the ages of 8 and 11 (M = 9.57; DE = 1.12). The Spanish versions of the SOP-C and SOP-S subscales of the Child/Adolescent Perfectionism Scale and the Aggression Questionnaire were used. Students with high SOP-C scored significantly higher (p < .001) than their peers with low SOP-C on all components of aggressive behavior. The magnitude of these differences (Cohen’s d index) ranged from .40 to .59. In contrast, non-significant statistical differences were found between students with high and low SOP-S. Moreover, logistic regression analysis revealed that SOP-C significantly and positively predicted high Hostility, Anger and Physical and Verbal Aggression, whereas none of these components were significantly predicted by SOP-S (95% CI). Results are discussed, taking into account the debate on the conceptualization and nature of intrapersonal perfectionism.
Protected areas are frequently used loci for ecological and conservation research, with several national/international designations identifying scientific research as a key objective. For example, Ecological Stations (ESs) in Brazil are strictly protected areas with the explicit goals of protecting nature and hosting scientific research. Nevertheless, simply mandating scientific research does not necessarily translate into action. Here, we quantitatively assess the scientific productivity of ESs and identify the main socio-ecological factors associated with different levels of scientific research. Specifically, we adopt a multi-model inference approach with a hurdle regression model to independently evaluate the factors associated with the presence/absence of research and the volume of studies in ESs. Surprisingly, given their stated remit, a large proportion of ESs had little or no scientific productivity. Results also indicate that older ESs were more likely to be associated with published research and that the volume of publications was associated with the number of years since the first article was published. The presence of a management plan and a management council were also significant positive drivers of research. Our results strongly suggest that, despite their clear mandate, ESs are not effectively fulfilling their role as a policy instrument for generating valuable scientific data.
Contextually appropriate interventions delivered by primary maternal care providers (PMCPs) might be effective in reducing the treatment gap for perinatal depression.
To compare high-intensity treatment (HIT) with low-intensity treatment (LIT) for perinatal depression.
Cluster randomised clinical trial, conducted in Ibadan, Nigeria between 18 June 2013 and 11 December 2015 in 29 maternal care clinics allocated by computed-generated random sequence (15 HIT; 14 LIT). Interventions were delivered individually to antenatal women with DSM-IV (1994) major depression by trained PMCPs. LIT consisted of the basic psychosocial treatment specifications in the World Health Organization Mental Health Gap Action Programme – Intervention Guide. HIT comprised LIT plus eight weekly problem-solving therapy sessions with possible additional sessions determined by scores on the Edinburgh Postnatal Depression Scale (EPDS). The primary outcome was remission of depression at 6 months postpartum (EPDS < 6).
There were 686 participants; 452 and 234 in HIT and LIT arms, respectively, with both groups similar at baseline. Follow-up assessments, completed on 85%, showed remission rates of 70% with HIT and 66% with LIT: risk difference 4% (95% CI −4.1%, 12.0%), adjusted odds ratio 1.12 (95% CI 0.73, 1.72). HIT was more effective for severe depression (odds ratio 2.29; 95% CI 1.01, 5.20; P = 0.047) and resulted in a higher rate of exclusive breastfeeding. Infant outcomes, cost-effectiveness and adverse events were similar.
Except among severely depressed perinatal women, we found no strong evidence to recommend high-intensity in preference to low-intensity psychological intervention in routine primary maternal care.
Infant protein intake has been associated with child growth, however, research on maternal protein intake during pregnancy is limited. Insulin-like growth factors (IGF) play a role in early fetal development and maternal protein intake may influence child body composition via IGF-1. The aim of this study was to investigate the association of maternal protein intake throughout pregnancy on cord blood IGF-1 and child body composition from birth to 5 years of age. Analysis was carried out on 570 mother–child dyads from the Randomised cOntrol trial of LOw glycaemic index diet study. Protein intake was recorded using 3-d food diaries in each trimester of pregnancy and protein intake per kg of maternal weight (g/d per kg) was calculated. Cord blood IGF-1 was measured at birth. Infant anthropometry was measured at birth, 6 months, 2 and 5 years of age. Mixed modelling, linear regression, and mediation analysis were carried out. Birth weight centiles were positively associated with early-pregnancy protein intake (g/d per kg), while weight centiles from 6 months to 5 years were negatively associated (B=−21·6, P<0·05). These associations were not mediated by IGF-1. Our findings suggest that high protein intake in early-pregnancy may exert an in utero effect on offspring body composition with a higher weight initially at birth but slower growth rates into childhood. Further research is needed to elucidate the exact mechanisms by which dietary protein modulates fetal growth.
The aim of this research was to investigate the influence of substrate roughness on the adhesion and tribological performance of thin TiN coatings obtained by physical vapor deposition. For that purpose, substrates of AISI H13 steel with surface finishes of 0.06, 0.28 and 0.90 μm in Ra were coated with TiN under the same coating conditions. The chemical composition of the steel, as well as that of the TiN coating, were obtained using EDS analysis. Adhesion tests were carried out following the procedure of BSi 1071-8 standard while hardness was evaluated by ASTM C 1327-03. On the other hand, dry sliding friction tests were conducted with a pin-on-disk tribometer, according to the ASTM G 99-05 standard. This study showed that the roughness of the coating increases as the substrate roughness increases. Regarding adhesion and hardness, all the samples showed an adhesion class 1 according to the standard and a hardness value of 14.51 GPa. Nevertheless, the highest substrate roughness produced the best adhesion. On the other hand, the lowest values for the friction coefficient and wear behavior were obtained by the sample with the lowest substrate roughness of 0.06 µm. In addition, it was found that friction and wear increase when the substrate roughness increases.
The influence of the concentration of carbon black nanoparticles on the mechanical behavior of a structural adhesive was studied to evaluate and understand the stiffness, strength, and deformation behavior of a reinforced epoxy adhesive. Two carbon black nanoparticles with different dielectric properties and sizes (Monarch® 120 and Vulcan® XC72R) were studied. A bi-component structural epoxy adhesive was selected. Specimens with different concentrations of carbon black were manufactured (0, 5, 10, and 20% on volume of resin) for each type of nanoparticle. The specimens were cured in a hydraulic hot-plates press machine. The mechanical behavior of the adhesives was found not to vary significantly as a function of carbon black nanoparticles amount. A scanning electron microscopy analysis was performed to evaluate the fracture surface. The fracture surfaces of specimens were correlated with the mechanical response obtained through tensile tests.
Many animals that swim or fly use their body to accelerate the fluid around them, transferring momentum from their flexible bodies and appendages to the surrounding fluid. The kinematics that emerge from this transfer result from the coupling between the fluid and the active and passive material properties of the flexible body or appendages. To elucidate the fundamental features of the elastohydrodynamics of flexible appendages, recent physical experiments have quantified the propulsive performance of flexible panels that are actuated on their leading edge. Here we present a complementary computational study of a three-dimensional flexible panel that is heaved sinusoidally at its leading edge in an incompressible, viscous fluid. These high-fidelity numerical simulations enable us to examine how propulsive performance depends on mechanical resonance, fluid forces, and the emergent panel deformations. Moreover, the computational model does not require the tethering of the panel. We therefore compare the thrust production of tethered panels to the forward swimming speed of the same panels that can move forward freely. Varying both the passive material properties and the heaving frequency of the panel, we find that local peaks in trailing edge amplitude and forward swimming speed coincide and that they are determined by a non-dimensional quantity, the effective flexibility, that arises naturally in the Euler–Bernoulli beam equation. Modal decompositions of panel deflections reveal that the amplitude of each mode is related to the effective flexibility. Panels of different material properties that are actuated so that their effective flexibilities are closely matched have modal contributions that evolve similarly over the phase of the heaving cycle, leading to similar vortex structures in their wakes and comparable thrust forces and swimming speeds. Moreover, local peaks in the swimming speed and trailing edge amplitude correspond to peaks in the contributions of the different modes. This computational study of freely swimming flexible panels gives further insight into the role of resonance in swimming performance that is important in the engineering and design of robotic propulsors. Moreover, we view this reduced model and its comparison to laboratory experiments as a building block and validation for a more comprehensive three-dimensional computational model of an undulatory swimmer that will couple neural activation, muscle mechanics and body elasticity with the surrounding viscous, incompressible fluid.
Respiratory infections among infants constitute a major burden to health care systems in developed nations, yet the course and risk factors leading to these conditions are poorly understood. We examine the longitudinal patterns of respiratory infection hospitalisation (RIH) and how these patterns are influenced by neonatal pulmonary morbidities. We included all live births (n = 429 058) occurring in the Australian state of Queensland between January 2009 and December 2015. Data were structured so that each participant had a record (present/absent) of RIH for each month from birth to 12 months. Initially, latent class growth analysis was used to identify the trajectories of RIH adjusted for spatial–temporal factors; using the identified trajectories of RIH as outcomes, we built a multinomial logistic regression model to identify neonatal predictors of RIH trajectories. Our results indicated that a four-class solution was the best fit to the data, comprising a ‘no-risk’ trajectory, a ‘low-risk’ trajectory, an ‘early-risk’ trajectory and a ‘chronic-risk’ trajectory. Compared with the no-risk trajectory, membership in the other trajectories was predicted by a range of neonatal pulmonary morbidities, with transient tachypnoea of newborn showing a specific relationship with the early-risk group and sleep apnoea showing a specific and strong risk with the chronic-risk group. Our findings suggest the possibility of identifying neonates at risk of recurrent RIH and implementing effective intervention strategies prior to neonatal discharge.
The functional composition of plant communities in montane regions has been studied for decades, and most recent analyses find that environmentally favourable landscapes at lower altitudes tend to be dominated by species with resource-acquisitive traits, while more resource-conservative taxa dominate higher-altitude communities. However, it is unclear the extent to which this pattern is driven by co-gradient variation within clades or changes in clade representation across the gradient. To test for co-gradient variation, species composition, phylogenetic structure and functional traits were quantified for 97 species within the plant family Melastomataceae at five locations across a 2500-m altitudinal gradient along Volcán Barva in Costa Rica. Average melastome leaf force to punch, specific leaf area and leaf size vary with altitude, while four other functional traits do not. Taxonomic dissimilarity between communities was correlated with altitudinal difference, while phylogenetic dissimilarity was correlated with altitudinal dissimilarity only when measured with a metric that emphasizes shallow turnover of the tips of the phylogeny. These results highlight how species turnover may be more pronounced than functional or phylogenetic variation along altitudinal gradients. In addition, these results highlight the conservation value of lowland tropical forests, which here harbour a disproportionate amount of phylogenetic and functional diversity.