This work analyzes the thermal behavior of a vehicle cabin by using a dynamic thermal model, which allows to accurately reproduce the vehicle interior temperature under different external ...environmental conditions. The thermal model considers heat transfer through the glazed and opaque surfaces of the vehicle using the energy balance method. It considers changes in weather conditions, vehicle geometry, body construction characteristics, types of opaque and glazed surfaces, and existing thermal loads. Experimental tests (with and without solar radiation) were carried out to validate the dynamic thermal model. The model predicts the temperature variations of the air inside the vehicle cabin. The results showed a maximum variation of 1.38 K without solar incidence and 3.78 K with solar radiation.
Keywords: dynamic thermal model, vehicle, heat balance, thermal load.
Resumen
El objetivo principal del presente trabajo fue analizar el comportamiento térmico de la cabina de un vehículo utilizando un modelo térmico dinámico, que permite reproducir de manera precisa el comportamiento de la temperatura interior del vehículo bajo distintas condiciones ambientales externas. El modelo térmico considera la transferencia de calor a través de las superficies acristaladas y opacas del vehículo utilizando el método de balance de energía, para lo cual se toman en cuenta los cambios en las condiciones climatológicas, la geometría del vehículo, las características constructivas de la carrocería, tipos de superficies opacas y acristaladas y las cargas térmicas existentes. Se realizaron ensayos experimentales (con y sin radiación solar) para validar el modelo térmico dinámico. El modelo permite reproducir las variaciones de la temperatura del aire interior de la cabina del vehículo. Los resultados obtenidos muestran una variación máxima de 1.38 K, sin incidencia solar y 3.78 K con radiación solar.
Palabras Clave: modelo térmico dinámico, vehículo, balance de calor, carga térmica.
•In the new model at limit d → 0 the usual Q10 model is recovered as a particular case•In the proposed model the activation energy (Ea) is temperature-dependent•The new model generalises the Q10 ...coefficient and unifies conflicting results•The mathematical model is based on the theory of deformed exponential functions•To challenge the usual model it is provided significant evidence in conflicting cases
The Q10 temperature coefficient, which is widely used in scientific literature, is a measure of the temperature sensitivity of chemical reaction rates or biological processes. However, the conclusions drawn from applying this coefficient to experimental data obtained from biological processes are not universal. In many biological processes, Q10 values are often discordant with the results predicted by the Arrhenius law. The hypothesis tested in the present study is that this problem arises mainly from the fact that the Q10 coefficient is defined by the ratio between rates described by exponential laws instead of power laws. Considering this hypothesis and the need to review the mathematical laws and models currently used to describe rates and Q10 coefficients, we propose a model beyond the usual Arrhenius theory or exponential decay law herein. The proposed mathematical model is based on the theory of deformed exponential functions, with the ordinary Q10 model representing the conventional exponential function. Therefore, all results following the standard model remain valid. Moreover, we include a Q10 free open-source code, written in Python, and compatible with Windows, Linux and macOS platforms. The validation of the proposed model and confirmation of the given hypothesis were performed based on the following temperature-dependent biological processes: soil organic carbon (SOC) decomposition (which is essential to forecast the impact of climate change on terrestrial ecosystems); the metabolism of Arctic zooplankton; physiological processes of the respiratory and cardiovascular systems; rate of oxygen consumption in mitochondria of the eurythermal killifish Fundulus heteroclitus, and leaf respiration.
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Memphis Hübner (1819) is the most species‐rich genus among the Neotropical Charaxinae, occurring from southern United States to Argentina. Memphis acidalia (Hübner, 1819; Anaeini), a common and ...widespread species distributed in all of South America east of the Andes, is part of a complex of superficially similar, and supposedly related, species with high intraspecific variability. Immature stages are fundamental sources of information for Anaeini taxonomy; however, knowledge on immature stages of Memphis is incomplete. Thus, we describe the immature external morphology, biology and behaviour, plus the chaetotaxy of the first instar of M. acidalia victoria (H. Druce, 1877) and provide distinguishing characteristics of its life stages from those of similar sympatric species, namely. Memphis moruus (Fabricius, 1775), Memphis editha (Comstock, 1961), Memphis philumena (Doubleday, 1849) and Memphis oenomais (Boisduval, 1870). In general, the immature stages are similar to other “moruus‐type'' species of Memphis, differing from other species mostly on the co lour patterns of the fifth instar and pupa.
It is unclear how athletes regulate their performance prior and during exercise when deceptive methods are applied. Therefore, the aim of this study was to test if time manipulation can influence ...pacing strategy and running performance. Ten recreationally active subjects were informed they would complete four 60-min time trials only with time feedback. The first session was a familiarization trial (60-min), and in the following three sessions, the time feedback was modified: normal chronometer (NC—60 min.), 10% faster (Faster chronometer—FC—54 min.), and 10% slower (slower chronometer—SC—66 min.). Total distance was different between conditions, while average of total speed, Heart Rate, oxygen consumption, and Rate of Perceived Exertion were similar (p > 0.05). A slow start pacing strategy was adopted in all conditions and did not differ between conditions when averaged across the session; however, when analyzing the first and final 10 min of the session, differences were found between conditions. Finally, the observed time was an important determinant of the regulation of exercise intensity, because, although the pacing strategy adopted in all conditions was regulated according to previous exercise information, adjustments were made in the initial (NC) and final (FC) phases of the trials.
In complex coronary artery disease, it is sometimes difficult to determine which lesions are associated with reversible ischemia and should be stented. Fractional flow reserve (FFR) is an established ...objective methodology to indicate which lesions produce ischemia. Despite this, the selection of lesions to be stented is often based on the subjectively interpreted angiogram alone. The aim of this study in patients admitted for elective percutaneous intervention (PCI) was to evaluate the change in strategy if the decision to intervene was based on FFR measurement rather than on angiographic assessment. Two hundred fifty consecutive patients (471 arteries) scheduled for PCI were included in this study. All stenoses ≥50% by visual estimation and initially selected to be stented by 3 independent reviewers were assessed by FFR measurements. If FFR was <0.75, stenting was performed; if FFR was ≥0.75, no interventional treatment was given. Optimal pressure measurements were obtained in 452 lesions (96%). Diameter stenosis was 62 ± 12%, and FFR was 0.67 ± 0.17 for the entire group. In 68% of the stenoses, initial strategy as assessed from the angiogram was followed, and in 32%, there was a change in the planned approach based on FFR. In 48% of the patients, there was ≥1 lesion in which the treatment decision was changed after physiologic measurements. In conclusion, in this prospective, nonselective, but complete study representing the real world of PCI, 32% of the coronary stenoses and 48% of patients would have received a different treatment if the decision had been based on angiography only, stressing the utility of physiologic assessment in refining decision making during PCI.
A proteomic analysis of the apoplastic fluid (APF) of coffee leaves was conducted to investigate the cellular processes associated with incompatible (resistant) and compatible (susceptible) Coffea ...arabica-Hemileia vastatrix interactions, during the 24-96 hai period. The APF proteins were extracted by leaf vacuum infiltration and protein profiles were obtained by 2-DE. The comparative analysis of the gels revealed 210 polypeptide spots whose volume changed in abundance between samples (control, resistant and susceptible) during the 24-96 hai period. The proteins identified were involved mainly in protein degradation, cell wall metabolism and stress/defense responses, most of them being hydrolases (around 70%), particularly sugar hydrolases and peptidases/proteases. The changes in the APF proteome along the infection process revealed two distinct phases of defense responses, an initial/basal one (24-48 hai) and a late/specific one (72-96 hai). Compared to susceptibility, resistance was associated with a higher number of proteins, which was more evident in the late/specific phase. Proteins involved in the resistance response were mainly, glycohydrolases of the cell wall, serine proteases and pathogen related-like proteins (PR-proteins), suggesting that some of these proteins could be putative candidates for resistant markers of coffee to H. vastatrix. Antibodies were produced against chitinase, pectin methylesterase, serine carboxypeptidase, reticuline oxidase and subtilase and by an immunodetection assay it was observed an increase of these proteins in the resistant sample. With this methodology we have identified proteins that are candidate markers of resistance and that will be useful in coffee breeding programs to assist in the selection of cultivars with resistance to H. vastatrix.
l
-Carnitine plays a key role in the regulation of energy metabolism and growth in fish. The aim of this study was to determine the effects of dietary
l
-carnitine levels on carnitine homeostasis and ...energy metabolism in diploid and triploid trout (
Oncorhynchus mykiss
). Diploid and triploid trout (29.5 ± 0.6 and 31.8 ± 0.5 g, respectively) were fed with three diets supplemented with 15, 200 or 530 mg
l
-carnitine/kg, respectively, for 56 days. Compared to 15 mg
l
-carnitine, total carnitine content increased in the liver by 182% in diploid and by 154% in triploid trout fed 530 mg
l
-carnitine. In muscle, total carnitine content increased by 60 and 73% in diploid and by 34 and 75% in triploid with the increase in dietary
l
-carnitine levels.
l
-Carnitine caused no significant change in the plasma concentrations of metabolites like proteins (ammonia, urea and protein), lipid (triglycerides), carbohydrate (glucose, lactate) and enzyme activities (lipase, lactate, alanine transaminase, lactic acid dehydrogenase). Triploid trout had significantly lower plasma ammonia (
P
= 0.003), lipase (
P
= 0.005) and triiodothyronine (T
3
;
P
= 0.003) levels than diploid trout. In conclusion, ploidy significantly affected the energy metabolism in rainbow trout, dietary
l
-carnitine levels altered the
l
-carnitine homeostasis, but not influence nutritional metabolism.
Drug interaction studies selecting patients in a real-life setting are scarce, and most studies to date are characterized by a small sample size.
To evaluate the effect of amiodarone on warfarin ...maintenance dose and adverse events in an anticoagulation cohort from a tertiary cardiovascular service.
This study recruited 866 patients, and oral anticoagulant therapy was monitored by the prothrombin time expressed as the international normalized ratio (INR). Genotyping of CYP2C9*2, CYP2C9*3, and VKORC1 3673 polymorphisms was performed.
Of the 866 patients, 111 (12.8%) were taking amiodarone and warfarin simultaneously, and 514 (59.4%) reached the therapeutic target dose. The warfarin maintenance dose was significantly lower in patients simultaneously using amiodarone (23.8 ± 11.3 mg/wk) compared with other patients (29.5 ± 14.3 mg/wk; P < 0.001). Patients taking amiodarone had higher INR/current dose ratios (0.83 ± 0.04 per mg) compared with patients not using amiodarone (0.71 ± 0.02 per mg, P = 0.001). Adverse event frequency was not different between the groups (P = 0.40). No genotype effect was noted on the odds of bleeding associated with amiodarone use.
Simultaneous use of amiodarone influences warfarin maintenance dose, but is not associated with adverse events.
New Findings
•
What is the central question of this study?
The hypothesis that nitric oxide and NMDA glutamate receptor activation modulate cardiovascular responses to the microinjection of methyl ...ATP into the paraventricular nucleus (PVN) was tested in the present study.
•
What is the main finding and its importance?
The cardiovascular responses that are evoked by the microinjection of methyl ATP into the PVN involve NO production that promotes glutamate release and a subsequent activation of NMDA glutamate receptors in postsynaptic pre‐autonomic neurons, modulating sympathetic nerve activity. Data show new insights into the role of the ATP–NO–glutamate pathway in the PVN in cardiovascular modulation.
We hypothesize that a local ATP–NO–NMDA glutamate receptor interaction in the paraventricular nucleus (PVN) modulates the baseline mean arterial pressure and heart rate in unanaesthetized rats. The microinjection of α,β‐methylene ATP methyl ATP; 0.06, 0.12 and 1.2 nmol (100 nl)−1 into the PVN caused pressor and tachycardiac responses. Cardiovascular responses evoked by methyl ATP 0.12 nmol (100 nl)−1 in the PVN were blocked by pretreatment with the ganglion blocker pentolinium (5 mg kg−1 i.v.). Also, responses to the injection of methyl ATP 0.12 nmol (100 nl)−1 into the PVN were reduced by pretreatment with the selective P2 purinergic receptor antagonist pyridoxalphosphate‐6‐azophenyl‐2′,4′‐disulfonic acid 0.5 nmol (100 nl)−1, the neuronal NO synthase inhibitor Nω‐propyl‐l‐arginine 0.04 nmol (100 nl)−1 or the selective NMDA glutamate receptor antagonist LY235959 2 nmol (100 nl)−1. In addition, an injection of the NO donor sodium nitroprusside 27 nmol (100 nl)−1 into the PVN caused similar cardiovascular responses to those observed after methyl ATP, which were blocked by local pretreatment with LY235959. Therefore, the present results suggest that cardiovascular responses evoked by methyl ATP in the PVN involve a local production of NO, which promotes local glutamate release and activation of NMDA receptors that are probably located in pre‐autonomic parvocellular neurons, leading to sympathetic nervous system stimulation.
Recent studies reported comparatively lower heterotrophic bacteria (HB) abundances in tropical regions, indicating that factors involved in bacterial losses could be more relevant in the tropics. ...Heterotrophic nanoflagellates (HNF) are considered the main predators of HB in aquatic ecosystems, and one should expect higher abundances in the tropics because of differences in the food web configuration (absence of large daphnids). However, there are no comprehensive studies comparing HB and HNF abundances in a latitudinal gradient. We hypothesized that HB abundance would be lower in the tropics because HNF abundance would be higher, resulting in a tighter HNF-HB coupling. To test this hypothesis, we compiled a large dataset of HB and HNF abundances from tropical and temperate freshwater environments. We found that both HB and HNF abundances were lower in the tropical region, and that HNF-HB coupling does not differ between temperate and tropical regions. The lower HNF abundance and lack of coupling may be explained by a strong top-down control on HNF and/or their herbivory preference. Besides, no relationship was found between bacterial specific growth rate and either chlorophyll-a and HB abundance, indicating that bacterial losses may have an important role in tropical freshwaters. Thus, we found that HNF is likely not the main controllers of HB abundance, and that grazing by ciliates and cladocerans, together with the physiological effects of higher temperatures, may explain the high bacterial loss rates in the tropics.
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