A novel simulation-based analysis of a stochastic HIV model with the time delay using high order spectral collocation technique

The economic impact of Human Immunodeficiency Virus (HIV) goes beyond individual levels and it has a significant influence on communities and nations worldwide. Studying the transmission patterns in HIV dynamics is crucial for understanding the tracking behavior and informing policymakers about the possible control of this viral infection. Various approaches have been adopted to explore how the virus interacts with the immune system. Models involving differential equations with delays have become prevalent across various scientific and technical domains over the past few decades. In this study, we present a novel mathematical model comprising a system of delay differential equations to describe the dynamics of intramural HIV infection. The model characterizes three distinct cell sub-populations and the HIV virus. By incorporating time delay between the viral entry into target cells and the subsequent production of new virions, our model provides a comprehensive understanding of the infection process. Our study focuses on investigating the stability of two crucial equilibrium states the infection-free and endemic equilibriums. To analyze the infection-free equilibrium, we utilize the LaSalle invariance principle. Further, we prove that if reproduction is less than unity, the disease free equilibrium is locally and globally asymptotically stable. To ensure numerical accuracy and preservation of essential properties from the continuous mathematical model, we use a spectral scheme having a higher-order accuracy. This scheme effectively captures the underlying dynamics and enables efficient numerical simulations.

Brain Tumor Segmentation Using Deep Learning on MRI Images

Brain tumor (BT) diagnosis is a lengthy process, and great skill and expertise are required from radiologists. As the number of patients has expanded, so has the amount of data to be processed, making previous techniques both costly and ineffective. Many academics have examined a range of reliable and quick techniques for identifying and categorizing BTs. Recently, deep learning (DL) methods have gained popularity for creating computer algorithms that can quickly and reliably diagnose or segment BTs. To identify BTs in medical images, DL permits a pre-trained convolutional neural network (CNN) model. The suggested magnetic resonance imaging (MRI) images of BTs are included in the BT segmentation dataset, which was created as a benchmark for developing and evaluating algorithms for BT segmentation and diagnosis. There are 335 annotated MRI images in the collection. For the purpose of developing and testing BT segmentation and diagnosis algorithms, the brain tumor segmentation (BraTS) dataset was produced. A deep CNN was also utilized in the model-building process for segmenting BTs using the BraTS dataset. To train the model, a categorical cross-entropy loss function and an optimizer, such as Adam, were employed. Finally, the model's output successfully identified and segmented BTs in the dataset, attaining a validation accuracy of 98%.

Assessment of erosion rate in a rainfed agricultural area on the Northwestern coast of Egypt using 137Cs measurements

In the present work, the use of the fallout radionuclide ¹³⁷Cs as a tracer for estimating soil redistribution rates over the past 60 years was tested in Egypt at an agricultural field with a smooth slope (0-10%) located in Ras El-Hekma on the Northwestern coast. The average annual soil erosion rate was derived from ¹³⁷Cs inventories (Bq m^-2) and by using the conversion Diffusion and Migration Model (DMM). The activity concentrations of ¹³⁷Cs with uncertainty ranging between 7.5 and 20.9% were measured using HPGe gamma spectrometry. Approximately exponential shape for the distribution of ¹³⁷Cs activity concentration was observed within the upper 20 cm of the soil profile associated with the reference site while for the study sites, the ¹³⁷Cs depth distribution profiles indicate generally an increase of activity reaching a maximum peak of ¹³⁷Cs usually at a depth of 10-15 cm followed by an abrupt exponential decrease of ¹³⁷Cs activity concentration with depth. The measured average reference inventory for this area was 697 Bq m^-2 with a coefficient of variation of 23%. This value is close to the estimated reference inventory using the conversion model, which was 744 Bq m^-2. Transect sampling strategy was adopted at the study area where three parallel transects were chosen based on the common slope. The estimated average annual erosion rate for the three transects was found to be 7.5 t ha^-1 y^-1, and sediment delivery ratio was approximately 98%, which shows the moderate vulnerability of the Ras El-Hekma area to water erosion.

Re-evaluating the Economic Injury Level for Alfalfa Weevil (Coleoptera: Curculionidae) Control in Low Desert Irrigated Alfalfa

Alfalfa (Medicago sativa L.) dominates cropping systems in the Western United States and is first in terms of acreage planted in Arizona. The alfalfa weevil, Hypera postica (Gylenhall) and/or Hypera brunneipennis (Boheman), respectively, is the most destructive pest in terms of yield loss in low desert-grown alfalfa hay. The current economic threshold of 15-20 larvae per sweep, established in California in 1975, is currently not suitable or adopted by growers in the western U.S. low desert. Here, we conducted 4 yr of field trials to re-evaluate this economic threshold. Supporting observations of agricultural growers and professionals in the region, our results indicate that the economic threshold established in 1975 is too high. Specifically, one to three large larvae often cause a significant decrease in yield justifying weevil control based on current hay prices and costs of insecticide application. These results are discussed in the context of sustainable alfalfa production in the western U.S. low desert.

Insight into the photocatalytic properties of diatomite@Ni/NiO composite for effective photo-degradation of malachite green dye and photo-reduction of Cr (VI) under visible light

Diatomite frustules decorated by nano Ni/NiO nanoparticles (Diatomite@Ni/NiO) were synthesized as a novel photocatalyst for effective degradation of malachite green cationic dye (M.G) and photocatalytic-reduction of Cr (VI) ions. The composite was characterized by different analytical techniques and revealed enhancing in the surface area (400 m²/g), 5.8 nm as average pore diameter and showed lower band gap energy (1.71 eV) than NiO as single phase. The photocatalytic activity of the composite in the removal of M.G and reduction of Cr (VI) was evaluated under visible light considering the pH, illumination time, catalyst mass, and the pollutants concentrations. The results revealed complete removal of 25 mg/L M.G can be achieved using 20 mg, 30 mg, 40 mg and 50 mg of the after 150 min, 90 min, 60 min, and 30 min, respectively. The complete degradation of 50 mg/L can be obtained after 240 min, 90 min, and 60 min using 20 mg, 40 mg, and 50 mg of the catalyst, respectively. This also was reported for the photocatlytic-reduction of 25 mg/L of Cr(VI) ions as the complete reduction was estimated after 180 min, 60 min and 30 min using 20 mg, 40 mg, and 50 mg, respectively. Also, 50 mg/L of Cr (VI) can be completely reduced after 240 min, 90 min, and 60 min using 20 mg, 40 mg, and 50 mg as catalyst dosage, respectively. The photocatalytic degradation of M.G controlled mainly by the generated electron-hole pairs and the superoxide species while the photocatalytic-reduction of Cr (VI) controlled mainly by the directly excited electrons of Ni/NiO and partially by the formed superoxide radicals. Hence, the synthetic diatomite@Ni/NiO composite can be considered as potential photocatalyst in the degradation of M.G dye and photoreduction of Cr (VI) ions.

First-line tracheal resection and primary anastomosis for postintubation tracheal stenosis

Introduction Tracheal stenosis following intubation is the most common indication for tracheal resection and reconstruction. Endoscopic dilation is almost always associated with recurrence. This study investigated first-line surgical resection and anastomosis performed in fit patients presenting with postintubation tracheal stenosis. Methods Between February 2011 and November 2014, a prospective study was performed involving patients who underwent first-line tracheal resection and primary anastomosis after presenting with postintubation tracheal stenosis. Results A total of 30 patients (20 male) were operated on. The median age was 23.5 years (range: 13-77 years). Seventeen patients (56.7%) had had previous endoscopic tracheal dilation, four (13.3%) had had tracheal stents inserted prior to surgery and one (3.3%) had undergone previous tracheal resection. Nineteen patients (63.3%) had had a tracheostomy. Eight patients (26.7%) had had no previous tracheal interventions. The median time of intubation in those developing tracheal stenosis was 20.5 days (range: 0-45 days). The median length of hospital stay was 10.5 days (range: 7-21 days). The success rate for anastomoses was 96.7% (29/30). One patient needed a permanent tracheostomy. The in-hospital mortality rate was 3.3%: 1 patient died from a chest infection 21 days after surgery. There was no mortality or morbidity in the group undergoing first-line surgery for de novo tracheal lesions. Conclusions First-line tracheal resection with primary anastomosis is a safe option for the treatment of tracheal stenosis following intubation and obviates the need for repeated dilations. Endoscopic dilation should be reserved for those patients with significant co-morbidities or as a temporary measure in non-equipped centres.

Host plant suitability and feeding preferences of the grapevine pest Abagrotis orbis (Lepidoptera: Noctuidae)

Thirteen plant species were tested for their suitability as hosts for Abagrotis orbis (Grote), a climbing cutworm pest of grapevines in British Columbia. Choice tests were also conducted to investigate larval feeding preferences for the Brassicaceae species joi choi, Brassica rapa variety. Chinensis L., spring draba; Draba verna L.; and shepherd's purse, Capsella bursa-pastoris (L.) Medik; compared with postdormant buds of grape, Vitis vinifera L. (Vitaceae), and leaves of nine other plant species from several families. Results showed that tah tsai, Brassica rapa L. variety rosularis (M. Tsen & S. H. Lee) Hanelt (Brassicaceae), is a superior host for A. orbis based on shorter time to adult eclosion, heavier pupae, and higher rates of survival. Later-instar larvae died when fed draba, whereas those reared on shepherd's purse did not survive beyond the third instar. White clover, Trifolium repens L. (Fabaceae), and grape leaves were unsuitable hosts throughout development. Fifth-instar A. orbis preferred plants of the Brassicaceae family, dandelion, Taraxacum officinale Weber (Asteraceae), and strawberry, Fragaria sp. L. (Rosaceae), compared with postdormant grape buds. The results of this study suggest that the winter annual mustards draba and shepherd's purse that often grow abundantly in vine rows might help reduce climbing cutworm damage to the buds of grapevines.

Synthesis, X-ray Structure, and Pharmacological Activity of Some 6,6-Disubstituted Chromeno[4,3-b]- and Chromeno- [3,4-c]-quinolines

Some chromeno[4,3-b]quinolines 4a-i were obtained from beta-chloro carboxyaldehydes 3a-c with different aniline derivatives namely, aniline, 4-fluoroaniline, and 2-aminophenol. Surprisingly, 3a-c reacted with 2-aminothiophenol and afforded the chromeno[3,4-c]quinoline derivatives 5a-c. Single-crystal X-ray diffraction studies of 4e and 5b provided good support for the established structure. Compounds 4b and 5b showed significant anti-inflammatory and ulcerogenic score activities compared to that of indomethacin.

Effect of temperature and relative humidity on the cellular defense response of Ephestia kuehniella larvae fed Bacillus thuringiensis

While maintained under all combinations of three temperatures and two RH, fifth instar larvae of the Mediterranean flour moth, Ephestia kuehniella were fed wheat treated with spores and crystals of Bacillus thuringiensis var. kurstaki. Larvae that had fed on wheat with the bacterial preparation contained higher concentrations of nodules in their haemocoel than did larvae fed on wheat without bacteria. Nodule concentrations in larvae fed untreated wheat were unaffected by temperature or relative humidity. Larvae fed treated wheat had higher nodule concentrations at 32 degrees C than at 15 and 23 degrees C, and higher nodule concentrations at a relative humidity of 85% than at 43%. The percentage of larvae that pupated was lower when larvae were fed the bacterial preparation, and was significantly higher at 23 degrees C than at 15 and 32 degrees C, regardless of whether larvae were fed bacteria or not. Less time was required for larvae to develop to pupation at higher temperatures and at higher humidity. Mean time to pupation was lower for bacteria-fed larvae than for those fed untreated wheat, and this appeared to be a result of truncation of the distribution of times to pupation because only rapidly developing larvae survived to pupation.

Potentiation of diclofenac-induced anti-inflammatory response by aminoguanidine in carrageenan-induced acute inflammation in rats: the role of nitric oxide

OBJECTIVE

To investigate whether aminoguanidine (AG) treatment enhances the anti-inflammatory effect of diclofenac in an acute inflammation model in rats.

MATERIAL AND METHODS

In 48 rats carrageenan-induced paw edema was used as an acute inflammation model. Inflammatory activity was assessed at 1.5, 3 and 6 h after sub-planter injection of carrageenan (0.1 ml of a 1% solution in 0.85% saline). The anti-inflammatory effect of diclofenac (25 mg/kg, i.p.) was studied in comparison to that of the selective inducible nitric oxide synthase (iNOS) inhibitor, AG, and of nitric oxide donor, sodium nitroprusside (SNP).

RESULTS

AG, failed to inhibit inflammation during the first 3 h following carrageenan administration, but caused a slight, although statistically insignificant inhibition at 6 h. Diclofenac significantly reduced the carrageenan-induced edema in rat paw at all the time points studied. Administration of diclofenac after AG pretreatment caused significant (P < 0.001) reduction in edema that was double that of diclofenac alone 6 h after carrageenan injection. Administration of SNP as a single dose after AG pretreatment prevented any potentiation of anti-inflammatory response that was observed in the case of AG combined with diclofenac treatment.

CONCLUSION

These results show that AG markedly potentiates the anti-inflammatory activity of diclofenac at 6 h and this potentiation effect is nitric oxide-dependent.

Protective effect of aminoguanidine against cardiovascular toxicity of chronic doxorubicin treatment in rats

The cardiotoxicity-induced by chronic treatment of doxorubicin have recently be attributed to free radical formation and/or release of nitric oxide. In the present study, an already established rat model of doxorubicin -induced cardiotoxicity was used. Doxorubicin in a total cumulative dose of 15 mgkg(-1) I.P. given in six equal injections over two week period was administered. After three weeks of doxorubicin administration, the blood pressure, serum lactate dehydrogenase, lipid peroxides, asites fluid and mortality rate were significantly increased. Doxorubicin-induced cardiotoxicity was further confirmed by examining the histopathology of heart sections. Myocardial fibres necrosis with prominent acute inflammatory cells were observed in rats hearts treated with doxorubicin. Aminoguanidine, an inhibitor of nitric oxide synthase, 100 mgkg(-1) injected every other day for two week was given concurrently with doxorubicin. Aminoguanidine given concurrently with doxorubicin return blood pressure, lactate dehydrogenase and lipid peroxides to normal control values. Furthermore, aminoguanidine reduces the mortality rate, ascites fluid formation- induced by doxorubicin and improved the histopathology of rats hearts treated with doxorubicin. In conclusion, inhibition of nitric oxide formation may be beneficial in protecting rat hearts against doxorubicin- induced cardiotoxicity.

Renal metabolism of acrylonitrile to cyanide: in vitro studies

Acrylonitrile (VCN) is a widely used industrial chemical. The present work examines the mechanism of its renal toxicity. In renal centrifugal fractions from Sprague-Dawley rats, the metabolism of VCN to cyanide (CN(-)) was highest in the microsomal fraction and required a NADPH-generating system in the presence of magnesium ions for maximum activity. This biotransformation of VCN to CN(-)was characterised with respect to time (15 min), microsomal protein concentration (3 mg ml(-1)), pH (7.5) and temperature (37 degrees C). The V(max)of the reaction was 118.2 pmol CN(-)mg(-1)protein min(-1)and K(m)was 160.2 micromol VCN. Activation of VCN to CN(-)was markedly increased in microsomes obtained from phenobarbital (PB), ethanol, 4-methylpyrazole and 3-methylcholanthrene-treated rats by 161.5, 89.6, 71.0 and 50.2%, respectively. Addition of SKF 525-A (5x10(-4)m) or benzimidazole (2 m m) to the incubation mixtures significantly inhibited VCN metabolism by 66.6 and 78.8%, respectively. VCN metabolism to CN(-)was enhanced significantly by the addition of 10 m m of glutathione (GSH), l -cysteine, d -penicillamine, cysteamine or 2-mercaptoethanol to 389.5, 886.5, 611. 1, 145.5 and 384.0% of control, respectively. These findings indicate that VCN is metabolised in the kidney via cytochrome P-450-dependent mixed function oxidase system. 1999 Academic Press.

Feeding cyromazine to Luhmann hens: residues in tissues and effects on some biochemical constituents

Cyromazine was fed to Luhmann hens at 0.15 ppm level supplemented the basal diet for 3 weeks. The build up of cyromazine residues in liver and muscles of hens up to 7th day, the balance between cyromazine intake and elimination had taken place between 7 and 10 days. After cyromazine was withdrawn from the diet its residues was depleted within 7 days. During the 3 weeks of feeding on the treated diet, the accumulated residues reduced the blood glucose and hepatic protein significantly up to 2 weeks, while the hepatic lipids was slightly increased on the 7th day. Also such residues had adverse effects on the activities of alkaline phosphatase (AP) and transaminases (GOT, GPT) and extend on red blood cells, white blood cells, hemoglobin content (Hb) and packed cell volume (PCV) compared with the untreated hens.