Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
PLoS One ; 19(5): e0302664, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38820359

RESUMO

The ever-increasing demand for electricity has presented a grave threat to traditional energy sources, which are finite, rapidly depleting, and have a detrimental environmental impact. These shortcomings of conventional energy resources have caused the globe to switch from traditional to renewable energy sources. Wind power significantly contributes to carbon-free energy because it is widely accessible, inexpensive, and produces no harmful emissions. Better and more efficient renewable wind power production relies on accurate wind speed predictions. Accurate short-term wind speed forecasting is essential for effectively handling unsteady wind power generation and ensuring that wind turbines operate safely. The significant stochastic nature of the wind speed and its dynamic unpredictability makes it difficult to forecast. This paper develops a hybrid model, L-LG-S, for precise short-term wind speed forecasting to address problems in wind speed forecasting. In this research, state-of-the-art machine learning and deep learning algorithms employed in wind speed forecasting are compared with the proposed approach. The effectiveness of the proposed hybrid model is tested using real-world wind speed data from a wind turbine located in the city of Karachi, Pakistan. Moreover, the mean square error (MSE), root mean square error (RMSE), and mean absolute error (MAE) are used as accuracy evaluation indices. Experimental results show that the proposed model outperforms the state-of-the-art legacy models in terms of accuracy for short-term wind speed in training, validation and test predictions by 98% respectively.


Assuntos
Previsões , Vento , Previsões/métodos , Modelos Teóricos , Energia Renovável , Algoritmos , Aprendizado de Máquina
2.
Front Plant Sci ; 13: 1035163, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36311077

RESUMO

Tomato is the second most important vegetable crop consumed globally, by the virtue of its antioxidant-rich phytochemicals and bioactive compounds. Identifying genotypes with high antioxidant capacities and nutritionally rich phytochemicals is imperative for improving human health. The present study aimed to analyze 21 antioxidant and nutritional compounds in 93 geographically diverse, high yielding, better quality, stress tolerant tomato genotypes (hybrids, parental lines, inbred lines, and advanced lines). Significant variation (p < 0.05) was detected for investigated traits among the tested genotypes. Principal component analysis revealed the hybrids NIAB-Jauhar, Iron-lady F1, NBH-258, Ahmar F1, NIAB-Gohar, the parents H-24, B-25, AVTO1080, Astra and AVTO1003, as well as the lines LBR-17, AVTO1315, AVTO1311 and Lyp-1 revealed superior performance for the traits such as chlorophylls, lycopene, total carotenoids, total antioxidant capacity, total oxidant status, protease, alpha-amylase and total flavonoid content. Whereas the hybrids Surkhail F1, NBH-204, NBH-229, NBH-151, NBH-196, NBH-152, NBH-261, NBH-228, NIAB-Jauhar, NBH-256 and NBH-255, the lines 21354, AVTO1315, Newcherry, LA4097, AVTO1311 and UAF-1 together with the parents Naqeeb, NCEBR-5, M-82 and LBR-10 exhibited significant contribution to the traits such as total soluble sugars, reducing sugars, malondialdehyde, ascorbic acid, esterase, peroxidase and superoxide dismutase. Moreover, the semi-determinate and determinate tomato genotypes together with the categories parent and line with positive factor scores of 3.184, 0.015, 0.325 and 0.186 in PC- I, exhibited better performance for the trait such as total chlorophylls, lycopene, total carotenoids, total oxidant status, protease, alpha-amylase, total antioxidant capacity, esterase and total flavonoid content. Whereas again the semi-determinate and indeterminate tomato genotypes along with the category hybrid with positive factor scores of 2.619, 0.252 and 0.114 in PC- II, exhibited better performance for the traits such as total soluble sugars, reducing sugars, chlorophyll b, malondialdehyde content, ascorbic acid, superoxide dismutase and peroxidase. Hybrid vigor was observed in the hybrids for investigated traits. The aforementioned tomato genotypes showing outstanding performance in the respective traits can be exploited in the breeding programs to improve nutritional quality of tomato that can further improve human health.

3.
Int J Mol Med ; 20(1): 91-5, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17549394

RESUMO

Insulin-like growth factor (IGF)-I is a ubiquitously synthesized peptide that, along with IGF-II, acts via the IGF-R type I receptor. IGF-I and its receptor are expressed in the adrenal gland of humans and bovines, the secretion of which they seem to stimulate. As in humans and cows, the main glucocorticoid hormone secreted by guinea-pig adrenals is cortisol, and hence we have studied the adrenocortical effects of IGF-I in this species. In vivo experiments showed that prolonged IGF-I administration raised the plasma concentration of cortisol in both normal and dexamethasone/captopril-treated guinea pigs, thereby ruling out the possibility that IGF-I may act by activating the hypothalamic-pituitary-adrenal axis and the renin-angiotensin system. In vitro experiments demonstrated that IGF-I enhanced basal, but not maximally agonist [ACTH and angiotensin-II (Ang-II)]-stimulated, cortisol secretion from freshly dispersed guinea-pig inner adrenocortical cells. The IGF-I immuno-neutralization suppressed the IGF-I secretagogue effect, without altering the cortisol response to both ACTH and Ang-II. IGF-I raised cyclic-AMP and inositol triphosphate release from dispersed guinea-pig cells, and the effect was reversed by the adenylate cyclase inhibitor SQ-22536 and the phospholipase-C (PLC) inhibitor U-73122. SQ-22536, U-73122, the protein kinase (PK) A inhibitor H-89 and the PKC inhibitor calphostin-C decreased by approximately 50% the cortisol response of dispersed cells to IGF-I, and the combined exposure to SQ-22536 and U-73122 abolished it. We conclude that IGF-I stimulates glucocorticoid secretion from guinea-pig adrenocortical cells, acting via selective receptors coupled to both the adenylate cyclase/PKA- and PLC/PKC-dependent signaling cascades.


Assuntos
Córtex Suprarrenal/citologia , Córtex Suprarrenal/fisiologia , Hidrocortisona/metabolismo , Fator de Crescimento Insulin-Like I/administração & dosagem , Fator de Crescimento Insulin-Like I/farmacologia , Córtex Suprarrenal/metabolismo , Animais , Captopril/farmacologia , AMP Cíclico/análise , AMP Cíclico/metabolismo , Dexametasona/farmacologia , Cobaias , Hidrocortisona/análise , Hidrocortisona/sangue , Técnicas In Vitro , Fosfatos de Inositol/análise , Fosfatos de Inositol/metabolismo , Masculino , Zona Fasciculada/fisiologia , Zona Reticular/fisiologia
4.
Int J Mol Med ; 17(4): 633-6, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16525720

RESUMO

Atrial natriuretic peptide (ANP) is a regulatory hormone widely expressed, along with its receptors, in organs and body tissues. ANP is well known to inhibit aldosterone secretion from mammalian adrenals, but its effect on glucocorticoid-hormone production is controversial. In vivo experiments showed that prolonged ANP administration raised the plasma concentration of cortisol in both normal and dexamethasone/captopril-treated guinea pigs (i.e. in animals with pharmacologically interrupted hypothalamic-pituitary-adrenal axis and renin-angiotensin system). ANP did not affect cortisol secretion from dispersed guinea pig zona fasciculata-reticularis cells, but enhanced catecholamine release from adrenomedullary cells. ANP stimulated cortisol output from guinea pig adrenal slices containing medullary chromaffin tissue, and the beta-adrenoceptor antagonist l-alprenolol blocked this effect. The conclusion is drawn that ANP, when the structural integrity of the adrenal gland is preserved, is able to enhance glucocorticoid secretion in guinea pigs, through an indirect mechanism involving the rise in the catecholamine release, which in turn, acting in a paracrine manner, stimulate secretion of inner adrenocortical cells.


Assuntos
Glândulas Suprarrenais/efeitos dos fármacos , Fator Natriurético Atrial/farmacologia , Hidrocortisona/metabolismo , Glândulas Suprarrenais/metabolismo , Medula Suprarrenal/efeitos dos fármacos , Medula Suprarrenal/metabolismo , Alprenolol/administração & dosagem , Alprenolol/farmacologia , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Fator Natriurético Atrial/administração & dosagem , Captopril/administração & dosagem , Captopril/farmacologia , Catecolaminas/metabolismo , Dexametasona/administração & dosagem , Dexametasona/farmacologia , Relação Dose-Resposta a Droga , Epinefrina/metabolismo , Feminino , Glucocorticoides/administração & dosagem , Glucocorticoides/farmacologia , Cobaias , Hidrocortisona/sangue , Técnicas In Vitro , Injeções Subcutâneas , Masculino , Norepinefrina/metabolismo , Comunicação Parácrina/efeitos dos fármacos , Comunicação Parácrina/fisiologia
5.
J Biosci ; 27(5): 509-13, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12381875

RESUMO

The ultrastructure of the corpuscles of Stannius (CS) of Heteropneustes fossilis reveals a homogenous cellular composition characterized by only one cell type, with large secretory granules and abundant ribosomal endoplasmic reticulum. These cells are comparable to the type 1 cell described in the CS of other teleosts; type 2 cells, whose presence is ubiquitous in the CS of freshwater species are absent in H. fossilis. Our data on the CS of H. fossilis demonstrate that not all freshwater species possess type 2 cells in their CS and these are not essential for life in freshwater


Assuntos
Peixes-Gato/anatomia & histologia , Glândulas Endócrinas/ultraestrutura , Animais , Microscopia Eletrônica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...