Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Ecotoxicol Environ Saf ; 227: 112941, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34710816

RESUMO

In the freshwater catfish, Mystus cavasius, locally known as gulsha, ovarian maturation is triggered by long-day conditions. Using dopaminergic neuronal activity in the brain, the purpose of this study was to identify the brain's detection of a nocturnal light pulse that induced ovarian development. Since direct inhibition of pituitary gonadotropin release is exerted by dopamine (DA), it may serve as a neuromodulator of photoperiodic stimulation in teleosts. We studied functional effects of photoperiodicity on dopaminergic rhythmicity in gulsha brain. Nocturnal illumination and Nanda-Hamner photocycles revealed that ovarian development is induced by a 1 h light pulse between zeitgeber time (ZT) 12 and 13. Daily fluctuations in DA, 3, 4-dihydroxyphenylacetic acid (DOPAC) and DOPAC/DA were observed under a 12L:12D photoperiod. Fish exhibited increased levels during the daytime and decreased levels at night. Rhythmic patterns of dopaminergic activity also showed clear circadian oscillations under constant light, but not constant dark conditions. After 7 days of exposure to long photoperiod (14L:10D), DA, DOPAC and DOPAC/DA in the brain at ZT12 and ZT16 were significantly higher than during a short photoperiod (10L:14D). Melatonin-containing water inhibited the release of DA and DOPAC 6 h and 24 h after treatment, respectively, and DOPAC/DA 6 h after treatment. This inhibition was blocked by the melatonin receptor antagonist, luzindole. These results suggest that a 1 h nocturnal light pulse induces ovarian development through alteration of dopaminergic neuronal excitability in the brain, via oscillation in melatonin triggered by photic stimuli, which may interfere with the reproductive endocrine axis in gulsha.


Assuntos
Peixes-Gato , Melatonina , Animais , Encéfalo , Dopamina , Luz , Fotoperíodo
2.
Int J Mol Sci ; 22(21)2021 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-34768875

RESUMO

Heavy metal toxicity is one of the most devastating abiotic stresses. Heavy metals cause serious damage to plant growth and productivity, which is a major problem for sustainable agriculture. It adversely affects plant molecular physiology and biochemistry by generating osmotic stress, ionic imbalance, oxidative stress, membrane disorganization, cellular toxicity, and metabolic homeostasis. To improve and stimulate plant tolerance to heavy metal stress, the application of biostimulants can be an effective approach without threatening the ecosystem. Melatonin (N-acetyl-5-methoxytryptamine), a biostimulator, plant growth regulator, and antioxidant, promotes plant tolerance to heavy metal stress by improving redox and nutrient homeostasis, osmotic balance, and primary and secondary metabolism. It is important to perceive the complete and detailed regulatory mechanisms of exogenous and endogenous melatonin-mediated heavy metal-toxicity mitigation in plants to identify potential research gaps that should be addressed in the future. This review provides a novel insight to understand the multifunctional role of melatonin in reducing heavy metal stress and the underlying molecular mechanisms.


Assuntos
Melatonina/farmacologia , Metais Pesados/toxicidade , Estresse Fisiológico/fisiologia , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Ecossistema , Fertilizantes , Melatonina/metabolismo , Melatonina/fisiologia , Metais Pesados/metabolismo , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Reguladores de Crescimento de Plantas/metabolismo , Plantas/efeitos dos fármacos , Plantas/metabolismo , Solo/química , Poluentes do Solo/metabolismo
3.
Data Brief ; 54: 110331, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38550233

RESUMO

The quality of datasets is crucial in computer graphics and machine learning research and development. This paper presents the Render Lighting Dataset, featuring 63,648 rendered images of Blender's primitive shapes with various lighting conditions and engines. The images were created using Blender 4.0's Cycles and Eevee Render Engines, with careful attention to detail in texture mapping and UV unwrapping. The dataset covers six different lighting conditions, including Area Light, Spotlight, Point Light, Tri-Light, HDRI (Sunlight), and HDRI (Overcast), each adjusted using Blender's different options in the Color Management panel. With thirteen unique materials, ranging from Coastal Sand to Glossy Plastic, the dataset provides visual diversity for researchers to explore material properties under different lighting conditions using different render engines. This dataset serves as a valuable resource for researchers looking to enhance 3D rendering engines. Its diverse set of rendered images under varied lighting conditions and material properties allows researchers to benchmark and evaluate the performance of different rendering engines, develop new rendering algorithms and techniques, optimize rendering parameters, and understand rendering challenges. By enabling more realistic and efficient rendering, advancing research in lighting simulation, and facilitating the development of AI-driven rendering techniques, this dataset has the potential to shape the future of computer graphics and rendering technology.

4.
Data Brief ; 53: 110109, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38357462

RESUMO

"Why don't students learn?" is a common question that educators try to address. To encourage students to become more engaged in the learning process, we believe in fostering their natural curiosity by encouraging them to ask high-level questions. To support this approach, we have compiled a dataset of questions that we hope will aid in the training of artificial intelligence (AI) models and ultimately improve the learning experience for students. To develop our dataset, we collected anonymous student questioning data in the Summer 2023 semester, utilizing our online application named "Palta Question", resulting in a dataset of 8,811 unique questions. The dataset consists of students' inquiries which underwent basic question validation using a sophisticated keyword-based approach, manual categorization by topic and course content, as well as complexity assessment using Bloom's taxonomy keywords which have also been included in the dataset. To ensure question uniqueness, we implemented the Levenshtein distance algorithm to exclude questions with a high similarity rate. This dataset provides targeted insights into student inquiry patterns and knowledge gaps within the domain of 'Introduction to Computers and Research' and 'Data Structure' courses, originating from the students at Independent University, Bangladesh (IUB). While its scope is confined to a specific student group and academic context, limiting broader applicability, it remains valuable for detailed studies in these subjects and serves as a useful foundation for AI-based educational research tools. To demonstrate the effectiveness of the dataset, we also tested it to train the AI to perform basic tasks like sorting questions according to their courses and topics. However, we envision researchers utilizing it to enhance education and aid in students' learning.

5.
Front Plant Sci ; 15: 1353352, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38689842

RESUMO

Among tropical fruit trees, coconut holds significant edible and economic importance. The natural growth of coconuts faces a challenge in the form of low temperatures, which is a crucial factor among adverse environmental stresses impacting their geographical distribution. Hence, it is essential to enhance our comprehension of the molecular mechanisms through which cold stress influences various coconut varieties. We employed analyses of leaf growth morphology and physiological traits to examine how coconuts respond to low temperatures over 2-hour, 8-hour, 2-day, and 7-day intervals. Additionally, we performed transcriptome and metabolome analyses to identify the molecular and physiological shifts in two coconut varieties displaying distinct sensitivities to the cold stress. As the length of cold stress extended, there was a prominent escalation within the soluble protein (SP), proline (Pro) concentrations, the activity of peroxidase (POD) and superoxide dismutase (SOD) in the leaves. Contrariwise, the activity of glutathione peroxidase (GSH) underwent a substantial reduction during this period. The widespread analysis of metabolome and transcriptome disclosed a nexus of genes and metabolites intricately cold stress were chiefly involved in pathways centered around amino acid, flavonoid, carbohydrate and lipid metabolism. We perceived several stress-responsive metabolites, such as flavonoids, carbohydrates, lipids, and amino acids, which unveiled considerably, lower in the genotype subtle to cold stress. Furthermore, we uncovered pivotal genes in the amino acid biosynthesis, antioxidant system and flavonoid biosynthesis pathway that presented down-regulation in coconut varieties sensitive to cold stress. This study broadly enriches our contemporary perception of the molecular machinery that contributes to altering levels of cold stress tolerance amid coconut genotypes. It also unlocks several unique prospects for exploration in the areas of breeding or engineering, aiming to identifying tolerant and/or sensitive coconut varieties encompassing multi-omics layers in response to cold stress conditions.

6.
Cureus ; 15(9): e45658, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37868568

RESUMO

Tumour-to-tumour metastases (TTM) are a rare phenomenon in which a primary tumour has metastasised within another distant primary tumour. We present the case of a 63-year-old female who presented with right-sided breast cancer. An incidental left-sided renal mass was detected on staging CT of the thorax, abdomen, and pelvis (CT-TAP). The patient had no evidence of metastases below the diaphragm. Histology following a radical left nephrectomy revealed metastatic breast cancer within a renal cell carcinoma (RCC). The patient underwent chemotherapy and surgery for right-sided breast cancer. Follow-up imaging demonstrated the metastatic spread of the breast cancer. This is an unusual case of TTM from breast to an initially occult RCC primary.

7.
Biol Trace Elem Res ; 201(1): 65-81, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35249208

RESUMO

In this study, the concentrations of iodine in household salt samples (n = 690) were determined by following the iodometric titration method, and the health risks of Bangladeshi people were assessed based on the semi-probabilistic approach and the US Environmental Protection Agency (USEPA) deterministic model. After adjusting 20% of cooking losses, the iodine concentration (mean, range) in salt samples of Phultala, Dighalia, Terokhada, Rupsha, Batiaghata, Dumuria, Paikgacha, Koyra, Dacope, and KCC was (29.68 ± 8.67, 14.39-48.26), (31.05 ± 6.68, 15.24-43.18), (26.94 ± 5.57, 16.09-45.72), (24.33 ± 5.61, 12.70-37.26), (26.69 ± 6.73, 10.16-44.87), (27.20 ± 8.44, 9.31-53.34), (27.71 ± 8.09, 8.46-47.42), (28.39 ± 7.80, 11.01-46.57), (28.20 ± 7.97, 3.38-49.10), and (29.21 ± 6.62, 18.62-40.64) mg/kg, respectively. The iodine contents in 97.25% of samples were within the standard fortification level of Bangladesh (15-50 mg/kg), while 2.61% of samples were below this limit. The semi-probabilistic risk assessment studies showed that 80.14% of samples at a low ingestion rate could provide optimal nutrition (150-299 µg/day) to the whole population. Contrarily, at medium, moderate-high, and high consumption rates 34.93%, 65.22%, and 85.94% of samples, respectively, belonged to above the requirements to excessive exposure categories (300-1100 µg/day), which might cause iodine-induced diseases. The target hazard quotient (THQ) values for the adults in most of the samples were within the threshold risk limit (THQ < 1.0), whereas THQ values in 6.82% to 85.97% of samples for the children at low to high ingestion rates, respectively exceeded this limit, which revealed that the adults were almost safe, but the children might face non-carcinogenic health effects. Therefore, regular monitoring of iodine concentration in iodized salts should be done to prevent iodine deficiency or iodine-induced disorders.


Assuntos
Iodo , Cloreto de Sódio na Dieta , Adulto , Criança , Humanos , Bangladesh/epidemiologia , Estudos Transversais , Cloreto de Sódio na Dieta/análise , Cloreto de Sódio , Medição de Risco
8.
Cureus ; 15(2): e35296, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36968878

RESUMO

INTRODUCTION:  Piriformis syndrome (PS) is a rare focal soft tissue rheumatic disease. Due to heavy rural work, we questioned whether PS was more prevalent in the rainy monsoon than in other seasons. In this pilot research, we studied the pattern of PS, the frequency of PS over the seasons, and whether there were typical preceding events.  Methods: In this time-series descriptive study, PS cases diagnosed in a community-based clinic between January 2018 and December 2019 were enrolled. PS was diagnosed by clinical features and a 50% immediate pain relief from ultrasonogram-guided lidocaine (2%) injection in the piriformis muscle (PM). PS mimics were excluded. RESULTS:  A total of 38 PS cases (11 males) were enrolled consecutively. In 2018, during dry winter (November-February), pre-monsoon (March-May), and rainy monsoon (June-October), nine, seven, and one PS cases were diagnosed, respectively; in 2019, the numbers were three, eight, and seven, respectively. Thus, over two years, 12 PS patients were diagnosed in dry winter, 15 in pre-monsoon, and eight in rainy monsoon. There was no correlation with the type of preceding events. There were no differences in the pattern of PS between the seasons. CONCLUSIONS:  In this pilot study, over two years more new PS cases were observed in the pre-monsoon and dry winter than in the rainy season; this was not supporting our research question. There was no association with specific preceding events.

9.
Accid Anal Prev ; 159: 106211, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34126276

RESUMO

Work zone safety management and research relies heavily on the quality of work zone crash data. However, it is possible that a police officer may misclassify a crash in structured data due to: restrictive options in the crash report; a lack of understanding about their importance; lack of time due to police officers' work load; and ignorance of work zone as one of the crash contributing factors. Consequently, work zone crashes are under representative in crash statistics. Crash narratives contain valuable information that is not included in the structured data. The objective of this study is to develop a classifier that applies text mining techniques to quickly find missed work zone (WZ) crashes through the unstructured text saved in the crash narratives. The study used three-year crash data from 2017 to 2019. The data from 2017 to 2018 was used as training data, and the 2019 data was used as testing data. A unigram + bigram noisy-OR classifier was developed and proven to be an efficient and effective means of classifying work zone crashes based on key information in the crash narrative. The ad-hoc analysis of misclassified work zone crashes sheds light on when, where and the plausible reasons as to why work zone crashes are more likely to be missed.


Assuntos
Acidentes de Trânsito , Polícia , Mineração de Dados , Humanos , Narração , Gestão da Segurança
10.
Chemosphere ; 187: 385-394, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28858718

RESUMO

High salinity is a major constraint for wheat productivity in many countries, including Bangladesh. Here, we examined the effects of salt-induced toxicity on growth and production of 10 local wheat cultivars by analyzing physiological, biochemical and agronomical responses to identify the salt-tolerant attributes among the contrasting genotypes. Results of cluster analyses based on salt tolerance indices of plant growth-related and yield-contributing parameters, ionic balance (Na+, K+ and Na+/K+ ratio), and stress indicators (SPAD values and proline) revealed Gourab and Shatabdi as salt-sensitive, BARI Gom 27 and 28 as salt-tolerant and the other six examined varieties as moderately salt-tolerant cultivars. Hierarchical clustering and principle component analyses also demonstrated BARI Gom 27 and 28 as the highest salt-tolerant cultivars, especially in terms of Na+/K+ ratio and proline level. Additionally, lower accumulations of hydrogen peroxide and malondialdehyde, and higher activities of antioxidant enzymes catalase, peroxidase and ascorbate peroxidase in the salt-tolerant BARI Gom 28 than in the salt-sensitive Gourab indicated reduced oxidative damage in BARI Gom 28 relative to that in Gourab. Collectively, our findings suggest that the optimum growth and yield of salt-tolerant cultivars are associated with decreased Na+/K+ ratio, increased proline level and reduced oxidative stress. Furthermore, BARI Gom 27 and 28 could be suggested as suitable cultivars for cultivation in salt-affected areas, and the contrasting salt-responsive genotypes can be used as valuable genetic resources in breeding and dissection of molecular mechanisms underlying wheat adaptation to high salinity.


Assuntos
Tolerância ao Sal/genética , Triticum/crescimento & desenvolvimento , Ascorbato Peroxidases , Bangladesh , Catalase , Genótipo , Íons , Estresse Oxidativo , Potássio , Prolina , Salinidade , Sódio , Triticum/efeitos dos fármacos , Triticum/genética
11.
Plant Signal Behav ; 11(11): e1247138, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27739913

RESUMO

Skunk cabbage (Symplocarpus renifolius) blooms in early spring and its inflorescence, referred to as the spadix, can produce enough heat to melt snow. Here, we investigated glycolytic carbon flow at the PEP branch-point in thermogenic spadices. Our analyses revealed that petals and pistils in thermogenic florets exhibited higher expression of SrPEPC and SrAOX transcripts than those of SrPK, SrPEPCK, and SrPEPtase. Moreover, enzymatic analyses showed high activities of PEPC in the extracts from thermogenic florets. Finally, mitochondria from thermogenic florets showed low respiratory activities when pyruvate was used as a substrate, although a significant malate-mediated cyanide-insensitive respiration was observed. Collectively, these results suggest that PEP metabolism, primarily catabolized by PEPC, plays a critical role in thermogenesis in S. renifolius.


Assuntos
Araceae/enzimologia , Citosol/enzimologia , Mitocôndrias/enzimologia , Proteínas Mitocondriais/metabolismo , Oxirredutases/metabolismo , Fosfoenolpiruvato Carboxilase/metabolismo , Proteínas de Plantas/metabolismo , Araceae/metabolismo , Citosol/metabolismo , Proteínas Mitocondriais/genética , Oxirredutases/genética , Fosfoenolpiruvato Carboxilase/genética , Proteínas de Plantas/genética , Temperatura
13.
Biosci Biotechnol Biochem ; 66(1): 44-50, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11866118

RESUMO

The pbp3 gene encoding PBP3 of Bacillus cereus was cloned and sequenced. For this purpose, PBP3 was first purified from B. cereus ts-4, and N-terminal amino acid sequences of the peptides obtained from the protease digests of the protein were analyzed. The B. cereus ts-4 pbp3 gene consisted of an open reading frame of 1,986 bp encoding 662 amino acid residues with a calculated molecular mass of 73,044 Da. The active site-motifs SXXK, SXN, and KTG are present at the positions 393, 452, and 590, respectively, in the deduced amino acid sequence. The pbp3 structural gene was ligated into the pET17 x b expression vector and pET-pbp3 was constructed. A protein was produced by the cells of E. coli carrying pET-pbp3. The produced protein migrated at about 75 kDa in SDS-polyacrylamide gel and strongly reacted with biotinylated ampicillin.


Assuntos
Proteínas de Transporte/genética , Expressão Gênica , Muramilpentapeptídeo Carboxipeptidase/genética , Sequência de Aminoácidos , Bacillus cereus , Sequência de Bases , Proteínas de Transporte/isolamento & purificação , Clonagem Molecular , DNA Complementar , Escherichia coli , Dados de Sequência Molecular , Muramilpentapeptídeo Carboxipeptidase/isolamento & purificação , Peptídeos/análise , Análise de Sequência de DNA , Análise de Sequência de Proteína , Homologia de Sequência de Aminoácidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA