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1.
Parasit Vectors ; 17(1): 187, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605410

RESUMO

BACKGROUND: In the context of climate change, a growing concern is that vector-pathogen or host-parasite interactions may be correlated with climatic factors, especially increasing temperatures. In the present study, we used a mosquito-microsporidian model to determine the impact of environmental factors such as temperature, humidity, wind and rainfall on the occurrence rates of opportunistic obligate microparasites (Microsporidia) in hosts from a family that includes important disease vectors (Culicidae). METHODS: In our study, 3000 adult mosquitoes collected from the field over 3 years were analysed. Mosquitoes and microsporidia were identified using PCR and sequencing of the hypervariable V5 region of the small subunit ribosomal RNA gene and a shortened fragment of the cytochrome c oxidase subunit I gene, respectively. RESULTS: DNA metabarcoding was used to identify nine mosquito species, all of which were hosts of 12 microsporidian species. The prevalence of microsporidian DNA across all mosquito samples was 34.6%. Microsporidian prevalence in mosquitoes was more frequent during warm months (> 19 °C; humidity < 65%), as was the co-occurrence of two or three microsporidian species in a single host individual. During warm months, microsporidian occurrence was noted 1.6-fold more often than during the cold periods. Among the microsporidians found in the mosquitoes, five (representing the genera Enterocytospora, Vairimorpha and Microsporidium) were positively correlated with an increase in temperature, whereas one (Hazardia sp.) was significantly correlated with a decrease in temperature. Threefold more microsporidian co-occurrences were recorded in the warm months than in the cold months. CONCLUSIONS: These results suggest that the susceptibility of mosquitoes to parasite occurrence is primarily determined by environmental conditions, such as, for example, temperatures > 19 °C and humidity not exceeding 62%. Collectively, our data provide a better understanding of the effects of the environment on microsporidian-mosquito interactions.


Assuntos
Culicidae , Microsporídios , Animais , Culicidae/parasitologia , Temperatura , Umidade , Mosquitos Vetores , Microsporídios/genética , DNA
2.
J Phys Chem A ; 128(15): 3015-3023, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38593044

RESUMO

Respiratory viruses, such as influenza and severe acute respiratory syndrome coronavirus 2, represent a substantial public health burden and are largely transmitted through respiratory droplets and aerosols. Environmental factors such as relative humidity (RH) and temperature impact virus transmission rates, and a precise mechanistic understanding of the connection between these environmental factors and virus transmission would improve efforts to mitigate respiratory disease transmission. Previous studies on supermicrometer particles observed RH-dependent phase transitions and linked particle phase state to virus viability. Phase transitions in atmospheric aerosols are dependent on size in the submicrometer range, and actual respiratory particles are expelled over a large size range, including submicrometer aerosols that can transmit diseases over long distances. Here, we directly investigated the phase transitions of submicrometer model respiratory aerosols. A probe molecule, Nile red, was added to particle systems including multiple mucin/salt mixtures, a growth medium, and simulated lung fluid. For each system, the polarity-dependent fluorescence emission was measured following RH conditioning. Notably, the fluorescence measurements of mucin/NaCl and Dulbecco's modified Eagle's medium particles indicated that liquid-liquid phase separation (LLPS) also occurs in submicron particles, suggesting that LLPS can also impact the viability of viruses in submicron particles and thus affect aerosol virus transmission. Furthermore, the utility of fluorescence-based measurements to study submicrometer respiratory particle physicochemical properties in situ is demonstrated.


Assuntos
Mucinas , Aerossóis e Gotículas Respiratórios , Umidade , Aerossóis/química
3.
Soft Matter ; 20(15): 3243-3247, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38572565

RESUMO

In this study, by fabricating DNA doped with tetraphenylethene-containing ammonium surfactant, the resulting solvent-free DNA ionic complex could undergo a humidity-induced phase change that could be well tracked by the fluorescence signal of the surfactant. Taking advantage of the humidity-induced change in fluorescence, the reported ionic DNA complex could accurately indicate the humidity in real time.


Assuntos
Cristais Líquidos , Cristais Líquidos/química , Umidade , Materiais Biocompatíveis , DNA/química , Tensoativos/química
4.
J Hazard Mater ; 470: 134278, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38631247

RESUMO

Resuspension caused by human walking activities is an important source of indoor bioaerosols and has been associated with health effects such as allergies and asthma. However, it is unknown whether inhalation of resuspended bioaerosols is an important exposure pathway for airborne infection. Also, crucial factors influencing the resuspension of settled microbes have not been quantified. In this study, we experimentally investigated the resuspension of culturable bacteria from human-stepping on polyvinyl chloride (PVC) flooring under different conditions. We determined the bacterial resuspension emission factor (ER), a normalized resuspension parameter for the ratio of resuspended mass in the air to the mass of settled particles, for two common bacteria, Escherichia coli and Salmonella enterica. The investigation involved varying factors such as microbial surface-attached durations (0, 1, 2, and 3 days), the absence or presence of nutrients on flooring surfaces, and changes in relative humidity (RH) (35%, 65%, and 85%). The results showed that, in the absence of nutrients, the highest ER values for E. coli and S. enterica were 3.8 × 10-5 ± 5.2 × 10-6 and 5.3 × 10-5 ± 6.0 × 10-6, respectively, associated with surface-attached duration of 0 days. As the surface-attached duration increased from 0 to 3 days, ER values decreased by 92% and 84% for E. coli and S. enterica, respectively. In addition, we observed that ER values decreased with the increasing RH, which is consistent with particle adhesion theory. This research offers valuable insights into microbial resuspension during human walking activities and holds the potential for assisting in the assessment and estimation of risks related to human exposure to bioaerosols.


Assuntos
Escherichia coli , Umidade , Caminhada , Humanos , Pisos e Cobertura de Pisos , Salmonella enterica , Aerossóis , Poluição do Ar em Ambientes Fechados , Microbiologia do Ar , Cloreto de Polivinila/química , Nutrientes
5.
Commun Biol ; 7(1): 465, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38632312

RESUMO

High temperature and humidity in the environment are known to be associated with discomfort and disease, yet the underlying mechanisms remain unclear. We observed a decrease in plasma glucagon-like peptide-1 levels in response to high-temperature and humidity conditions. Through 16S rRNA gene sequencing, alterations in the gut microbiota composition were identified following exposure to high temperature and humidity conditions. Notably, changes in the gut microbiota have been implicated in bile acid synthesis. Further analysis revealed a decrease in lithocholic acid levels in high-temperature and humidity conditions. Subsequent in vitro experiments demonstrated that lithocholic acid increases glucagon-like peptide-1 secretion in NCI-H716 cells. Proteomic analysis indicated upregulation of farnesoid X receptor expression in the ileum. In vitro experiments revealed that the combination of lithocholic acid with farnesoid X receptor inhibitors resulted in a significant increase in GLP-1 levels compared to lithocholic acid alone. In this study, we elucidate the mechanism by which reduced lithocholic acid suppresses glucagon-like peptide 1 via farnesoid X receptor activation under high-temperature and humidity condition.


Assuntos
Microbioma Gastrointestinal , Peptídeo 1 Semelhante ao Glucagon , Animais , Camundongos , Peptídeo 1 Semelhante ao Glucagon/genética , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Umidade , Proteômica , RNA Ribossômico 16S , Temperatura , Fatores de Transcrição , Ácidos e Sais Biliares , Ácido Litocólico
6.
PLoS One ; 19(4): e0297381, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38635828

RESUMO

The new thermal insulating shotcrete is of great significance for the management of thermal damage in deep mines, and its own strength has a greater impact on the roadway insulation and safe production, so it is very necessary to study the shear strength of the new thermal insulating shotcrete under the influence of the deep hot and humid environment and the stress of mining. For the heat-insulating shotcrete, firstly, we carried out the concrete variable angle shear test under different loading rates, which concluded that the shear rate and peak shear stress showed a trend of increasing and then decreasing; as the angle increases, the different rates have a greater impact on the peak shear stress of the specimen. Secondly, the concrete variable angle shear test was carried out under the temperature and humidity cycle, which revealed that the shear strength of thermal insulated shotcrete increased firstly and then decreased with the increase of temperature at the same number of cycles. Finally, the empirical equations between the cohesive force c, the angle of internal friction ϕ and the number of warm and wet cycles n and the temperature of warm and wet cycles T are fitted with the MATLAB software respectively, and the research results provide technical references for the management of geothermal temperature in deep well projects.


Assuntos
Temperatura Alta , Temperatura , Umidade , Estresse Mecânico
7.
Sci Rep ; 14(1): 9130, 2024 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-38644400

RESUMO

Rice serves as a fundamental food staple for humans. Its production process, however, unavoidably exposes it to pesticides which may detrimentally impact its quality due to residues. Therefore, it is extremely necessary to monitor pesticide residues on rice during storage. In this research, the Quatformer model, which considers the effects of temperature and humidity on pesticide residues in rice grains, was utilized to forecast the amount of pesticide residues in rice grains during the storage process, and the predicted results were combined with actual observations to form a quality assessment index. By applying the K-Means algorithm, the quality of rice grains was graded and assessed. The findings indicated that the model had high prediction accuracy, and the MAE, MSE, MAPE, RMSE and SMAPE indexes were calculated to be 0.0112, 0.0814, 0.1057, 0.1055 and 0.0204, respectively. These findings provide valuable technical and theoretical support for planning storage conditions, enhancing pesticide residue decomposition, and monitoring rice quality during storage.


Assuntos
Armazenamento de Alimentos , Oryza , Resíduos de Praguicidas , Oryza/química , Resíduos de Praguicidas/análise , Armazenamento de Alimentos/métodos , Contaminação de Alimentos/análise , Temperatura , Algoritmos , Umidade
8.
Sci Rep ; 14(1): 9163, 2024 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-38644433

RESUMO

Emerging infestations of bed bugs are affecting normal human lifestyle globally. This study has been designed to optimize the rearing conditions for Cimex lectularius L. (Hemiptera), to support the scientific research on them. Bed bugs have been projected onto three different temperature (20 °C, 25 °C, and 30 °C) and relative humidity (50%, 70%, and 90%) conditions to check their overall growth and survival rate. Adult mortality, weight loss, egg laying, percentage hatching, hatching initiation and completion, nymph mortality, and molting have been evaluated to optimize the best conditions. The temperature at 25 °C with 90% RH showed minimum mortality for adults (female 13.33 ± 3.33% and male 6.67 ± 3.33%) and nymphs (13.33 ± 3.33%), while maximum egg laying (40.33 ± 1.86), with highest percentage hatching (98.23 ± 0.58%). At 30 °C with 90% RH, hatching initiation and completion (5.19 ± 0.12 days and 7.23 ± 0.16 days) as well as molting initiation and completion (3.73 ± 0.12 days and 7.00 ± 0.24 days) were found to be fastest. Thus, it can be concluded that 25 °C with 90% RH is ideal for rearing of adults and 30 °C with 90% RH is appropriate for rapid growth of nymphs.


Assuntos
Percevejos-de-Cama , Umidade , Ninfa , Temperatura , Animais , Percevejos-de-Cama/crescimento & desenvolvimento , Percevejos-de-Cama/fisiologia , Feminino , Masculino , Ninfa/crescimento & desenvolvimento , Muda/fisiologia , Laboratórios
9.
Sci Data ; 11(1): 425, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658632

RESUMO

Near-surface atmospheric moisture is a key environmental and hydro-climatic variable that has significant implications for the natural and human systems. However, high-resolution moisture data are severely lacking for fine-scale studies. Here, we develop the first 1 km high spatial resolution dataset of monthly moisture index collection in China (HiMIC-Monthly) over a long period of 2003~2020. HiMIC-Monthly is generated by the light gradient boosting machine algorithm (LightGBM) based on observations at 2,419 weather stations and multiple covariates, including land surface temperature, vapor pressure, land cover, impervious surface proportion, population density, and topography. This collection includes six commonly used moisture indices, enabling fine-scale assessment of moisture conditions from different perspectives. Results show that the HiMIC-Monthly dataset has a good performance, with R2 values for all six moisture indices exceeding 0.96 and root mean square error and mean absolute error values within a reasonable range. The dataset exhibits high consistency with in situ observations over various spatial and temporal regimes, demonstrating broad applicability and strong reliability.


Assuntos
Atmosfera , China , Tempo (Meteorologia) , Umidade , Algoritmos , Monitoramento Ambiental/métodos
10.
Genet Sel Evol ; 56(1): 23, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38553689

RESUMO

BACKGROUND: In the current context of climate change, livestock production faces many challenges to improve the sustainability of systems. Dairy farming, in particular, must find ways to select animals that will be able to achieve sufficient overall production while maintaining their reproductive ability in environments with increasing temperatures. With future forecasted climate conditions in mind, this study used data from Holstein and Montbeliarde dairy cattle to: (1) estimate the genetic-by-temperature-humidity index (THI) interactions for female fertility, and (2) evaluate the production-fertility trade-off with increasing values of THI. RESULTS: Two-trait random regression models were fitted for conception rate (fertility) and test-day protein yield (production). For fertility, genetic correlations between different THI values were generally above 0.75, suggesting weak genotype-by-THI interactions for conception rate in both breeds. However, the genetic correlations between the conception rate breeding values at the current average THI (THI = 50, corresponding to a 24-h average temperature of 8 °C at 50% relative humidity) and their slopes (i.e., potential reranking) for heat stress scenarios (THI > 70), were different for each breed. For Montbeliarde, this correlation tended to be positive (i.e., overall the best reproducers are less affected by heat stress), whereas for Holstein it was approximately zero. Finally, our results indicated a weak antagonism between production and fertility, although for Montbeliarde this antagonism intensified with increasing THI. CONCLUSIONS: Within the range of weather conditions studied, increasing temperatures are not expected to exacerbate the fertility-production trade-off. However, our results indicated that the animals with the best breeding values for production today will be the most affected by temperature increases, both in terms of fertility and production. Nonetheless, these animals should remain among the most productive ones during heat waves. For Montbeliarde, the current selection program for fertility seems to be adequate for ensuring the adaptation of fertility traits to temperature increases, without adverse effects on production. Such a conclusion cannot be drawn for Holstein. In the future, the incorporation of a heat tolerance index into dairy cattle breeding programs would be valuable to promote the selection of animals adapted to future climate conditions.


Assuntos
Transtornos de Estresse por Calor , Leite , Animais , Bovinos/genética , Feminino , Umidade , Temperatura , Leite/metabolismo , Lactação/genética , Temperatura Alta , Fertilidade/genética , Transtornos de Estresse por Calor/veterinária
11.
Food Chem ; 446: 138885, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38447387

RESUMO

Biobased multi-stimulation materials have received considerable attention for intelligent packaging and anti-counterfeiting applications. Cellulose nanocrystals (CNCs) and cyanidins are good material candidates for monitoring food freshness as they are eco-friendly natural substances. This work incorporated cyanidin with a CNC-hosting substrate to develop a simple, environment-friendly colorimetric device to visualize food freshness. Across the pH range of 2-13, the indicator exhibited noticeable color changes ranging from red to gray and eventually to orange. The CNC-cyanidin (CC) film exhibited a dramatic color change from blue to dark red and high sensitivity at a relative humidity of 30 %-100 %. In corresponding to the total volatile elemental nitrogen (TVB-N) level of shrimp, the indicator showed distinguishable colors at different stages of shrimp. The findings imply that the samples have substantial potential for use as an intelligent indicator for tracking shrimp freshness.


Assuntos
Antocianinas , Alimentos Marinhos , Umidade , Concentração de Íons de Hidrogênio , Antocianinas/química , Embalagem de Alimentos
12.
Food Chem ; 447: 138926, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-38471278

RESUMO

4-Terpineol (4-TA), a typical monocyclic monoterpene essential oil compound with important biological activities, poor stability and solubility severely hamper its biological activities. To date, ß-cyclodextrin (ß-CD) encapsulating essential oil to form inclusion complexes (ICs) is considered as a satisfactory treatment. Nevertheless, the detailed inclusion mechanism of ß-CD for 4-TA especially the behavior of 4-TA during inclusion formation have not available yet. Herein, 4-TA/ß-CD ICs were successfully synthesized by the co-precipitation method, and hydrogen bonds and hydrophobic interactions played a key role in the formation of ICs, and the isopropyl of 4-TA entered the cavity through the wide rim of ß-CD. Moreover, the release profile demonstrated that high RH (85 % and 99 %) triggered the release of TA from ICs. This study suggests the great potential of cyclodextrin inclusion strategy for improving the stability and sustained release of 4-TA in food preservation application.


Assuntos
Ciclodextrinas , Óleos Voláteis , beta-Ciclodextrinas , Umidade , beta-Ciclodextrinas/química , Ciclodextrinas/química , Óleos Voláteis/química , Solubilidade
13.
Animal ; 18(4): 101112, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38518429

RESUMO

Feedlot cattle are at times exposed to high environmental temperatures. Faecal cortisol metabolites were related to possible indicators of heat stress that could be measured under field conditions: respiratory dynamics (respiration rate), body surface temperature and adaptive behaviours, such as water consumption, posture (standing, lying), and activity (eating, drinking and rumination). Twelve (12) yearling Black Angus steers were divided into two treatment groups: a hot treatment (HOT; n = 6) and a thermoneutral-treatment (TN; n = 6) and individually housed in a climate-controlled facility at The University of Queensland, Australia. In the TN treatment, all animals were exposed to an ambient temperature of 20.34 ± 0.25 °C, relative humidity 71.51 ± 3.26% and Temperature humidity index (THI) 66.91 ± 0.33 throughout. In the HOT treatment group, environmental conditions were exposed to different climatic phases from thermoneutral to hot conditions, where they remained for 7 d, and then returned to TN conditions in the recovery period. The dry bulb ambient temperature (TA) and relative humidity (RH) in the pens of cattle in the HOT treatment were increased from 28 °C (daily maximum ambient temperature) and 45% RH at 0700 h to a daily maximum TA and RH of 35 °C (daily maximum ambient temperature) and 50% (THI 77) at 1100 h, which was maintained until 1600 h, after which it declined until it reached the baseline at 2000 h. In both treatments, there was a significant decrease in faecal cortisol metabolite concentration from the start to the end of the experiments they adapted to the experimental facility. The concentration of faecal cortisol metabolites was greater in the HOT treatment, compared to the TN treatment during the heat exposure period, but there was no difference in the transition or recovery periods. Respiration rate was greater in the HOT treatment during heat exposure, and it increased with ambient dry bulb temperature above 26 °C, the latter being the upper critical temperature. Although positive correlations were detected between faecal cortisol metabolites and body surface temperature measurements, particularly the shoulder and rump, as well as standing time, panting score and drinking, a stepwise regression found that faecal cortisol metabolites were only significantly correlated with one variable, respiration rate. It is concluded that respiration rate is the best indicator of the stress induced by hot conditions for cattle.


Assuntos
Temperatura Corporal , Hidrocortisona , Bovinos , Animais , Temperatura Alta , Temperatura , Resposta ao Choque Térmico , Umidade
14.
Colloids Surf B Biointerfaces ; 237: 113831, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38508084

RESUMO

Biofilms are complex porous materials formed by microorganisms, polysaccharides, proteins, eDNA, inorganic matter, and water. They are ubiquitous in various environmental niches and are known to grow at solid-liquid, solid-air and air-liquid interfaces, often causing problems in several industrial and sanitary fields. Their removal is a challenge in many applications and numerous studies have been conducted to identify promising chemical species as cleaning agents. While these substances target specific components of biofilm structure, the role of water content in biofilm, and how it can influence wettability and detergent absorption have been quite neglected in the literature. Estimating water content in biofilm is a challenging task due to its heterogeneity in morphology and chemical composition. In this study, we controlled water content in Pseudomonas fluorescens AR 11 biofilms grown on submerged glass slides by regulating environmental relative humidity after drying. Interfacial properties of biofilm were investigated by measuring wetting of water and soybean oil. The morphology of biofilm structure was evaluated using Confocal Laser Scanning Microscopy and Scanning Electron Microscopy. The results showed that biofilm water content has a significant and measurable effect on its wettability, leading to the hypothesis that a preliminary control of water content can play a crucial role in biofilm removal process.


Assuntos
Pseudomonas fluorescens , Molhabilidade , Pseudomonas fluorescens/fisiologia , Umidade , Biofilmes , Água
15.
Sci Rep ; 14(1): 6339, 2024 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-38491197

RESUMO

Detailed examinations of the internal structure of tablets are imperative for comprehending their formulation, physical attributes, and ensuring their safe utilization. While X-ray computed tomography (CT) is valuable for noninvasively analyzing internal structural changes, the influence of humidity on these structural changes remains unexplored. Accordingly, we aimed to assess the viability of X-ray CT in non-destructively evaluating the internal structure of humidified magnesium oxide (MgO) tablets. MgO tablets were subjected to conditions of 40 °C and 75% humidity for 7 days, weighed pre- and post-humidification, and subsequently stored at room temperature (22-27 °C) until day 90. Their internal structure was evaluated using X-ray CT. We observed a substantial increase in the weight of MgO tablets concomitant with moisture absorption, with minimal changes observed upon storage at room temperature. The skewness reduced immediately post-moisture absorption, remained almost the same post-storage at room temperature, and failed to revert to pre-humidification levels during the storage period. These findings highlight the utility of X-ray CT as an effective tool for non-destructive, three-dimensional, and detailed evaluation of internal structural transformations in MgO tablets.


Assuntos
Óxido de Magnésio , Tomografia Computadorizada por Raios X , Óxido de Magnésio/química , Fenômenos Químicos , Comprimidos/química , Umidade
16.
ACS Sens ; 9(3): 1584-1591, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38450591

RESUMO

Chemoresistive gas sensors made from SnO2, ZnO, WO3, and In2O3 have been prepared by flame spray pyrolysis. The sensors' response to CO and NO2 in darkness and under illumination at different wavelengths, using commercially available LEDs, was investigated. Operation at room temperature turned out to be impractical due to the condensation of water inside the porous sensing layers and the irreversible changes it caused. Accordingly, for sensors operated at 70 °C, a characterization procedure was developed and proven to deliver consistent data. The resulting data set was so complex that usual univariate data analysis was intricate and, consequently, was investigated by correlation and principal component analysis. The results show that light of different wavelengths affects not only the resistance of each material, both under exposure to the target gases in humidity and in its absence, but also the sensor response to humidity and the target gases. It was found that each of the materials behaves differently under light exposure, and it was possible to identify conditions that need further investigations.


Assuntos
Gases , Análise Multivariada , Umidade , Porosidade , Análise de Componente Principal
17.
PLoS One ; 19(3): e0300920, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38512950

RESUMO

We previously reported that variations in the number and type of bacteria found in public spaces are influenced by environmental factors. However, based on field survey data alone, whether the dynamics of bacteria in the air change as a result of a single environmental factor or multiple factors working together remains unclear. To address this, mathematical modeling may be applied. We therefore conducted a reanalysis of the previously acquired data using principal component analysis (PCA) in conjunction with a generalized linear model (Glm2) and a statistical analysis of variance (ANOVA) test employing the χ2 distribution. The data used for the analysis were reused from a previous public environmental survey conducted at 8:00-20:00 on May 2, June 1, and July 5, 2016 (regular sampling) and at 5:50-7:50 and 20:15-24:15 on July 17, 2017 (baseline sampling) in the Sapporo underground walking space, a 520-meter-long underground walkway. The dataset consisted of 60 samples (22 samples for "bacterial flora"), including variables such as "temperature (T)," "humidity (H)," "atmospheric pressure (A)," "traffic pedestrians (TP)," "number of inorganic particles (Δ5: 1-5 µm)," "number of live airborne bacteria," and "bacterial flora." Our PCA with these environmental factors (T, H, A, and TP) revealed that the 60 samples could be categorized into four groups (G1 to G4), primarily based on variations in PC1 [Loadings: T(-0.62), H(-0.647), TP(0.399), A(0.196)] and PC2 [Loadings: A(-0.825), TP(0.501), H(0.209), T(-0.155)]. Notably, the number of inorganic particles significantly increased from G4 to G1, but the count of live bacteria was highest in G2, with no other clear pattern. Further analysis with Glm2 indicated that changes in inorganic particles could largely be explained by two variables (H/TP), while live bacteria levels were influenced by all explanatory variables (TP/A/H/T). ANOVA tests confirmed that inorganic particles and live bacteria were influenced by different factors. Moreover, there were minimal changes in bacterial flora observed among the groups (G1-G4). In conclusion, our findings suggest that the dynamics of live bacteria in the underground walkway differ from those of inorganic particles and are regulated in a complex manner by multiple environmental factors. This discovery may contribute to improving public health in urban settings.


Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Bactérias , Umidade , Modelos Teóricos , Microbiologia do Ar
18.
J Forensic Sci ; 69(3): 888-904, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38528830

RESUMO

There are many factors that may affect the longevity of or guide the use of canine training aids. Literature to date has mainly focused on identifying the headspace volatiles associated with training aids or odors and only minimal research exists into how different variables may alter those volatiles. The current study examines several factors affecting canine training aids: humidity, air flow, transportation, and operational deployment, using the triacetone triperoxide polymer odor capture-and-release canine training aid (TATP POCR) as the target. The TATP POCR is an absorption-based canine training aid developed to be used to safely train canines to detect the odor of the explosive TATP in operational settings. Comparisons of the TATP POCR to neat TATP are made throughout the manuscript. First, humidity increased the background components of the POCR matrix, as well as the amount of TATP recovered was above the POCR. Humidity thus affected the amount of TATP detected but did not prevent detection. Second, air flow lessened the lifetime of the TATP POCR. Third, the practice of using primary and secondary containment successfully prevented contamination, cross-contamination, and significant target loss, thereby maintaining kit integrity. Finally, the absorption of background odors from training environments was not observed. TATP headspace concentrations between a Deployed and Control POCR kit were not significantly different at time 0 (i.e., upon opening), which suggests that the operational use does not affect the function of the TATP POCR system. This information provides pivotal evidence for explosives detection canine handlers or trainers who utilize the TATP POCR.


Assuntos
Umidade , Odorantes , Cães , Animais , Compostos Heterocíclicos com 1 Anel , Peróxidos/análise , Movimentos do Ar , Polímeros , Substâncias Explosivas
19.
Biomacromolecules ; 25(4): 2367-2377, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38456841

RESUMO

Soil quality is one of the main limiting factor in the development of the food sector in arid areas, mainly due to its poor mechanics and lack of water retention. Soil's organic carbon is nearly absent in arid soils, though it is important for water and nutrient transport, to soil mechanics, to prevent erosion, and as a long-term carbon sink. In this study, we evaluate the potential benefits that are brought to inert sand by the incorporation of a range of, mainly, cellulosic networks in their polymeric or structured (fiber) forms, analogously to those found in healthy soils. We explore the impact of a wide range of nonfood polysaccharide-based amendments, including pulp fibers, nanocellulose, cellulose derivatives, and other readily available polysaccharide structures derived from arthropods (chitosan) or fruit peels (pectin) residues. A practical methodology is presented to form sand-polymer composites, which are evaluated for their soil mechanics as a function of humidity and the dynamics of their response to water. The mechanics are correlated to the network of polymers formed within the pores of the sandy soil, as observed by electron microscopy. The response to water is correlated to both the features of the network and the individual polysaccharides' physicochemical features. We expect this work to provide a rapid and reproducible methodology to benchmark sustainable organic amendments for arid soils.


Assuntos
Celulose , Areia , Benchmarking , Umidade , Solo/química , Água/química , Polímeros
20.
Int J Biometeorol ; 68(4): 777-793, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38427096

RESUMO

To adapt to Earth's rapidly changing climate, detailed modelling of thermal stress is needed. Dangerous stress levels are becoming more frequent, longer, and more severe. While traditional measurements of thermal stress have focused on air temperature and humidity, modern measures including radiation and wind speed are becoming widespread. However, projecting such indices has presented a challenging problem, due to the need for appropriate bias correction of multiple variables that vary on hourly timescales. In this paper, we aim to provide a detailed understanding of changing thermal stress patterns incorporating modern measurements, bias correction techniques, and hourly projections to assess the impact of climate change on thermal stress at human scales. To achieve these aims, we conduct a case study of projected thermal stress in central Hobart, Australia for 2040-2059, compared to the historical period 1990-2005. We present the first hourly metre-scale projections of thermal stress driven by multivariate bias-corrected data. We bias correct four variables from six dynamically downscaled General Circulation Models. These outputs drive the Solar and LongWave Environmental Irradiance Geometry model at metre scale, calculating mean radiant temperature and the Universal Thermal Climate Index. We demonstrate that multivariate bias correction can correct means on multiple time scales while accurately preserving mean seasonal trends. Changes in mean air temperature and UTCI by hour of the day and month of the year reveal diurnal and annual patterns in both temporal trends and model agreement. We present plots of future median stress values in the context of historical percentiles, revealing trends and patterns not evident in mean data. Our modelling illustrates a future Hobart that experiences higher and more consistent numbers of hours of heat stress arriving earlier in the year and extending further throughout the day.


Assuntos
Transtornos de Estresse por Calor , Modelos Teóricos , Humanos , Temperatura , Umidade , Vento , Sensação Térmica
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