bluuebunny/crossref_metadata_2025 huggingface dataset:
Astaxanthin Production by Newly Isolated Rhodosporidium toruloides: Optimization of Medium Compositions by Response Surface Methodology
Authors: TRAN Tuyet Nhung , TRAN Quang-Vinh , HUYNH Hao Thanh , HOANG Nghia-Son , NGUYEN Hoang Chinh , NGO Dai-Nghiep
Published: December 2018

Astaxanthin is a valuable carotenoid pigment, which has been extensively used in various industries. In this study, Rhodosporidium toruloides was first used as a new microbial source for producing natural astaxanthin. Various carbon, nitrogen, and mineral sources were evaluated for their effect on astaxanthin production of R. toruloides. Response surface methodology (RSM) was then used to optimize the medium compositions for maximizing the astaxanthin concentration. Among the examined nutrients, glucose, peptone, and KH2PO4 were the most efficient carbon, nitrogen, and mineral source for astaxanthin production, respectively. Through RSM, a maximum astaxanthin concentration of 927.11 µg l-1 was obtained by using Hansen broth containing 83.74 g l-1 glucose, 20.01 g l-1 peptone, and 6.19 g l-1 KH2PO4. This study suggested that R. toruloides is a promising candidate to produce natural astaxanthin.
Transcriptome Sequencing of Two Kentucky Bluegrass (Poa pratensis L.) Genotypes in Response to Heat Stress
Authors: LI Qiong , HE Yali , TU Mingyue , YAN Junhui , YU Liangliang , QI Weiwei , YUAN Xiaojun
Published: December 2018

Kentucky bluegrass (Poa pratensis L.) (KBG) is a major cool-season turfgrass. However, as its complex genetic background and production modes, limited genomic and transcriptomic information of KBG was known so far. In this study, a transcriptome study between wild type material Ninglan (summer stress sensitive) and cultivar material KBG03 (summer stress tolerant) was conducted, under optimal (25 °C) and high (40 °C) temperatures. A total of 81.42 Gb clean reads were generated and de novo assembled into 110,784 unigenes with an average length of 1,105 bp. About 50% KBG unigenes were similar to the non-redundant (NR) database. Among the NR BLASTx top hits, 27.47% unigenes were matched to Brachypodium distachyon. After heat stress, a massive amount of unigenes showed significantly differential expression in both genotypes. After 2h heat stress, more specially up-regulated differentially expressed unigenes (DEGs) and less down-regulated DEGs were detected in Ninglan than in KBG03. At 24h, the expression of 1710 and 730 unigenes were increased and decreased uniquely in Ninglan, and 1361 up-regulated DEGs and 757 down-regulated DEGs were just found in KBG03. More heat shock proteins (HSPs) and heat shock transcription factors (HSFs) DEGs were also identified at 2h than 24h in both genotypes. In addition, by Gene Ontology (GO) enrichment analysis, three core terms (“protein folding”, “response to heat”, and “response to hydrogen peroxide”) of biological process (BP) ontology were found in both genotypes under different heat stress time. The DEGs shared in both genotypes might be related to the basic mechanism of thermal response in KBG.
Callus Induction in Baru (Dipteryx alata Vog.) Explants
Authors: REZENDE Rodrigo Kelson S. , SCOTON Ana Maria N. , JESUS Maílson V. , PEREIRA Zeva V. , PINTO Fernanda
Published: December 2018

Baru (Dipteryx alata Vog.) is a species with great economic and environmental potential; it has popular acceptance, besides being a very productive species. Alternative propagation methods are important for species maintenance and exploration. Thus, micropropagation emerged as an alternative technique, providing genetic stability and the production of a large number of seedlings. The aim of the present investigation was to develop a callus induction protocol for in vitro baru explants. The tested explants were nodal, internodal and foliar segments. The explants were disinfected for 30 seconds in 70% alcohol (v/v) and 2 minutes in sodium hypochlorite (1.25% active chlorine). This was followed by triple washing. The inoculation was carried out in test tubes containing 15 mL MS medium (30 g L-1 sucrose, 6 g L-1 agar and 100 mg L-1 ascorbic acid) supplemented with 2.0 mg L-1 naphthalene acetic acid (NAA). The solution also contained 0.0, 2.5 or 5.0 mg L-1 of 6-benzylaminopurine (BAP) with the pH adjusted to 5.8. In the incubation phase, the explants were cultured for seven days in the dark and then subjected to a photoperiod of 16 hours (43 µmol m-2 s-1) at 25 ± 2 °C. The treatments were studied with 2.5, 5.0, 7.5 or 10.0 mg L-1 BAP additions to the MS. Callus formation, contamination and oxidation evaluations were undertaken. The results obtained when using 2.0 mg L-1 NAA concluded that such a treatment should be used to induce callogenesis from nodal explants, while for the tested baru leaf explants, the best results for callus formation were given by the combination of 2.0 mg L-1 NAA with 2.5 mg L-1 of BAP to.
In vitro Antifungal Activity of a New Bioproduct Obtained from Grape Seed Proanthocyanidins on Botrytis cinerea Mycelium and Spores
Authors: NECHITA Ancuța , FILIMON Razvan V. , FILIMON Roxana M. , COLIBABA Lucia-Cintia , GHERGHEL Daniela , DAMIAN Doina , PAȘA Rodica , COTEA Valeriu V.
Published: December 2018

Botrytis cinerea is a necrotrophic fungus that affects over 200 plant species. In vineyards, this pathogen is responsible for one of the most important diseases, commonly known as botrytis bunch rot or grey mould. Keeping infection under control with synthetic fungicides leads to an increased biological resistance of pathogen populations. An alternative way to synthetic products is to obtain natural fungicides by using bioactive compounds of plants. This study focuses on the antifungal properties of a new bioproduct obtained from polymeric proanthocyanidins extracted from grape seeds of ‘Fetească neagră’ variety. The bioproduct in solid state presented a total content of polyphenols of 0.625 mg GAE mg-1, a polyphenolic index of 17.40 and an antioxidant activity of 91.27% scavenged DPPH. The bioproduct with polyphenolic structure showed a moderate effect on the radial growth of fungal mycelium, at EC50 values between 11.23 and 12.15 mg mL-1. Effective antifungal activity was showed in the inhibition of spore germination, where the EC50 values varied from 1.14 to 1.47 mg mL-1. These in vitro results sustain the possibility of including the bioproduct in the category of natural fungicides for biological control against Botrytis cinerea fungus.
Antioxidant Capacity, Total Phenols, Total Flavonoids and Colour Component of Cornelian Cherry (Cornus mas L.) Wild Genotypes
Authors: COSMULESCU Sina N. , TRANDAFIR Ion , CORNESCU Felicia
Published: December 2018

A number of selected cornelian cherry wild genotypes were investigated regarding antioxidant capacity, total phenols, total flavonoids and colour component. The total phenolic, total flavonoids and antioxidant activity of methanol extract of cornelian cherry fruits were determined using Folin-Ciocalteu, colorimetric and DPPH methods, respectively. Total phenolic content ranged from 163.69 (S1) to 359.28 (H2) mg GAE 100 g-1 FW. Genotypes H2 and H3 had the highest total phenolic content (359.28 and 343.50 mg GAE 100 g-1 FW, respectively), total flavonoids (54.26 and 64.48 mg QE 100 g-1 FW, respectively) and antioxidant capacity (2.39 and 2.71 mmolTrolox100g-1 FW, respectively). Significant differences of yellow/blue color component (b*), red/ green (a*) color component, values of lightness (L*) and chroma (C) were obtained for extracts from fruits. The present study shows the potential of certain cornelian cherry genotypes as valuable source of natural antioxidants and gene stock for breeding programs.
Lithothamnion calcareum Nanoparticles Increase Growth of Melon Plants
Authors: NEGREIROS Andreia M.P. , SALES JÚNIOR Rui , MAIA JÚNIOR Francisco F. , SILVA Rodolfo B. , COSTA José A.P. , MEDEIROS Erika V.
Published: December 2018

The application of alternative fertilizers to the soil in a sustainable way in order to supply nutrients to plants is important for growers and for the environment. Calcareous algae, Lithothamnion calcareum (Lit), is considered an alternative fertilizer because it is rich in nutrients, particularly magnesium and calcium, that are essential for plants. The objective of this study was to investigate the effect of different formulations, doses and fertilization intervals of L. calcareum on growth of melon plants. Two experiments were performed. The first experiment aimed to evaluate the effect of various formulations and doses of Lit on the growth of melon plants. The second experiment was carried out to evaluate the use of formulations and fertilization intervals of Lit. Formulations and doses of Lit had a significant effect on the efficiency in the development of melon plants. No impact was observed when using a concentrated suspension of Lit. However, four applications of Lit nanoparticle formulations every 7 days increased the growth of melon plants at doses close to 1 kg ha-1. We provide the first data related to beneficial effects on melon growth of L. calcareum, in different formulations, application intervals and doses, applied to red-yellow soil.
Identification of Soils Factors Influence in the Distributions of Tuber aestivum in Transylvanian Subcarpathian Hill, Romania
Authors: PĂCURAR Horea , DÎRJA Marcel , BUTA Mihai , PĂCURAR Ioan , ROȘCA Sanda , BILAȘCO Ștefan
Published: December 2018

Truffles are one of the most hunted varieties of mushrooms in Europe due to their high price and their increasingly frequent use in the kitchen. As demonstrated by several studies, soil conditions are among the main factors that influence the spread and development of the black truffle species. The purpose of this study was to identify the soil factors which directly and indirectly influence the distribution of black truffles (Tuber aestivum Vittad.) in Romania and to identify the areas from the Subcarpathian Hills of Transylvania which are highly favourable to their existence and growth, using G.I.S. spatial analysis and databases which include soil characteristics (soil type, texture, gleization, stagno-gleization) and territorial localisation through GPS points indicating the samples of Tuber aestivum. By implementing the statistical model of spatial analysis (BSA – Bivariate Statistical Analysis) for each characteristic, a series of areas were classified into three classes of favourability (low, medium, high) for the growth of Tuber aestivum. The results were validated indirectly by comparing the overlapping of the areas from the high favourability class with the areas covered with tree species from the Quercus genus and directly, through field research (on the surfaces with maximum favourability), done by specialised truffle seekers. The results were validated with a very high confidence rate for both methods (method 1 - overlapping of approximatively 93%, method 2 - Tuber aestivum was identified on 12 out of 15 test surfaces from the high favourability class).
Evaluation of the Phytochemical, Antioxidant, Antibacterial and Anticancer Activity of Prunus domestica Fruit
Authors: EL-BELTAGI Hossam S. , EL-ANSARY Abeer E. , MOSTAFA Mai A. , KAMEL Teba A. , SAFWAT Gehan
Published: December 2018

Plants have been used long ago through man history of life for their use in food and medicinal drives. In modern life, natural products have been extracted and isolated from several kinds of plants for the development of new drugs. There are numerous interests in natural antioxidants extracted from medicinal plants, vegetables and fruits, which might help to prevent oxidative damage. One of such plants is plum Prunus domestica L., family Rosaceae. Samples from ‘African Rose’, and ‘Santa Rosa’ plum cultivars were collected from local market in Giza governorate, Egypt. The main phytochemicals of plums (fruit flesh and skin) were analyzed. Total polyphenols, flavonoids, tannins, anthocyanins, and reducing power were higher in ‘African Rose’ fruit. The ethanolic and ethyl acetate extracts of two plum cultivars were both high in the antioxidant effect with IC50 13.923 and 18.416 μg/ml of ethanolic extract of ‘African Rose’, and ‘Santa Rosa’ respectively. The IC50 of ‘African Rose’ and ‘Santa Rose’ extract against Caco-2 was 4 and 8.5 μg/ml. GC-MS analysis was carried out, fourteen and twenty one compound were identified in ‘Santa Rosa’ and ‘African Rose’ respectively. The fruits had an antimicrobial action against gram positive and negative bacteria. There was anticancer activity against 3 cell lines: Liver cell line (HepG2), colorectal adenocarcinoma (Caco-2) cell line, and breast cell line (MCF-7).
Effects of Vanadium and Nickel on Morphological Characteristics and on Vanadium and Nickel Uptake by Shoots of Mojito (Mentha × villosa) and Lavender (Lavandula anqustifolia)
Authors: BAROUCHAS Pantelis E. , AKOUMIANAKI-IOANNIDOU Anastasia , LIOPA-TSAKALIDI Aglaia , MOUSTAKAS Nicholas K.
Published: December 2018

Vanadium and Nickel may enter the human food chain through medicinal and culinary plants which in great doses are toxic to human, so it is important to determine their potential toxicity and health risk. Therefore, the objective of this work was to study the effects of Vanadium and Nickel on morphological characteristics and on Vanadium and Nickel uptake by shoots of mojito (Mentha × vilosa) and lavender (Lavandula anqustifolia). A completely randomized block design with five Vanadium treatments (0, 5, 10, 20, 40 mg V L-1) and five replications per treatment and another one with five Nickel treatments (0, 5, 10, 20 and 40 mg Ni L-1) and five replications per treatment for mojito and lavender were conducted in pots. No visible toxic or inhibitory symptoms were observed on the plants due to the increasing amounts of Vanadium or Nickel. Shoot dry matter and root dry matter of mojito and lavender decreased with increasing Vanadium rates. Vanadium uptake by shoots of mojito and lavender increased linearly with increasing Vanadium rates. Nickel uptake by shoots of lavender increased linearly with increasing rates of Nickel. Mojito is a Nickel accumulator.
Characterization of the Spectrum of Solar Irradiance under Different Crop Protection Coverings in Mediterranean Conditions and Effect on the Interception of Photosynthetically Active Radiation
Authors: GURREA-YSASI Gonzalo , BLANCA-GIMÉNEZ Vicente , FITA Inmaculada C. , FITA Ana , PROHENS Jaime , RODRÍGUEZ-BURRUEZO Adrián
Published: December 2018

Plants use visible light and part of adjacent ultraviolet and near infrared regions for photosynthesis. Crop protection coverings enable plant cultivation in areas or seasons not suitable open field. However, the use of covering materials is a detriment to solar irradiance, which may decrease the photosynthetic rate. Here, the effect of two different covering materials, tempered glass and white polyethylene mesh, on solar irradiance was compared to open field (control) under real farming conditions. Relative irradiance (RI) and photosynthetic photon flux density (PPFD) were recorded along 380-780 nm wavelength spectrums in the two conditions at 10:00 h and 13:00 h. Also the efficiency of Capsicum peppers in capturing solar irradiance was evaluated in leaves as the reflectance of both RI and PPFD under the mentioned growing conditions. Low differences in RI among the three conditions were found, and the lowest values corresponded to glasshouse conditions. Differences were more obvious in PPFD and, compared to open field, both mesh greenhouse and glasshouse conditions provoked remarkable decreases in all the spectral bands, 50-55% and 75-80% respectively. Covering materials also differed on the ratio of reflected PPFD and incident PPFD. Glasshouse plants displayed the highest reflectance at both 10:00 h and 13:00 h (0.05-0.20), followed by mesh greenhouse (0.05-0.10), suggesting that glasshouse conditions might decrease the photosynthesis rate due to both PPFD decrease and reflectance, although the effect of polyethylene mesh should not be disregarded as it also decreases considerably PPFD. Our results have important implications for the physiology and the productivity of crops under different covering materials.
The Effect of a Sugar-Containing Preservative on Senescence-Related Processes in Cut Clematis Flowers
Authors: RABIZA-ŚWIDER Julita , SKUTNIK Ewa , JĘDRZEJUK Agata
Published: December 2018

Clematis is a new species grown as cut flower, whose vase life is variable and cultivar-depended. Little is known about senescence of its cut flowers and their response to flower preservatives. The aim of the study was to evaluate the effect of a preservative (standard preservative SP, 8-hydroxyquinoline citrate plus sucrose) or a biocide solution (8-HQC) on certain senescence-related processes in cut clematis flowers. Analyses were done immediately after harvest and at the end of the vase life when control flowers held in water were wilting. A possible relationship between senescence parameters and the vase life of clematis taxa was also sought. As in most cut flowers, the contents of reducing sugars and soluble proteins in clematis petals decreased during the vase life while the proteolytic activity, including that of the cysteine protease, increased and was accompanied by accumulation of free proline and ammonium. Cut flower longevity in cultivars under study was not associated with the initial levels of reducing sugars, soluble proteins or free proline. Neither was the initial proteolytic activity or its increase during vase life related to the vase life itself: cultivars having comparable life spans differed dramatically in the initial and final proteolytic activities. Both solutions containing 8-HQC significantly affected the senescence-related processes and flowers held in them had more soluble proteins and lower proteolytic activity (total, and that of the cysteine protease) than control flowers held in water. Approximately a twofold increase in reducing sugars was observed in flowers held in SP relative to those held in water or in 8-HQC while the accumulation of free proline and ammonium was limited in their petals. This suggests a regulating action of exogenous sugar in senescence of clematis flowers. However, the delay of senescence produced by the preservative was not always associated with a longer vase life in any given cultivar. Further studies are needed to elucidate the role of sugar in clematis flower senescence.
Yield, Quality and Phytochemicals of Organic and Conventional Raspberry Cultivated in Chihuahua, Mexico
Authors: FRIAS-MORENO María N. , OLIVAS-OROZCO Guadalupe I. , GONZALEZ-AGUILAR Gustavo A. , BENITEZ-ENRIQUEZ Yael E. , PAREDES-ALONSO Adriana , JACOBO-CUELLAR Juan L. , SALAS-SALAZAR Nora A. , OJEDA-BARRIOS Damaris L. , PARRA-QUEZADA Rafael A.
Published: December 2018

Raspberry production represents an alternative for farmers in the temperate zones of Mexico. Due to the environmental impact caused by conventional agriculture, there is currently greater demand for organic food in the national and international market. To achieve this need, new fertilization techniques based on organic amendments are being tested. In the present study, yields and quality were evaluated over a 3-year period (2015, 2016 and 2017) as well as the phytochemical compounds of the production in 2017, with management of organic versus conventional fertilization of raspberry crop in open field in Cuauhtémoc, Chihuahua, Mexico. During the three years of study, the conventional fertilization system obtained higher yields, compared to the organic one, with values of 2,698 and 2,351 g per linear meter in 2015, 2,423 and 1,301 g per linear meter in 2016 and the data for 2017 were 3,077 and 2,550 g per linear meter, respectively. Regarding quality, the results showed no statistical differences between the two systems of production about colour, firmness, total soluble solids, titratable acidity and pH of the fruit. Differently the composition of phytochemicals, phenols, flavonoids, total anthocyanins and antioxidant capacity was better under the organic management. In conclusion, the conventional system showed higher yields, the quality of the fruits was not different between the two systems, while the levels of phytochemicals were higher with the organic farming. Therefore, it is important to continue the research in order to improve soil fertility and achieve higher yields under the organic management.
Zinc Nutritional Status on Physiological and Nutritional Indicators, Metabolism of Oxidative Stress, Yield and Fruit Quality of Pecan Tree
Authors: OJEDA-BARRIOS Damaris , CASTILLO-GONZALEZ Jorge , HERNANDEZ-RODRIGUEZ Adriana , ABADIA Javier , SANCHEZ Estaban , PARRA-QUEZADA Rafael , VALLES-ARAGON Maria-Cecilia , SIDA-ARREOLA Juan A. Pedro
Published: December 2018

In the United States of America and in Mexico, zinc deficiency is a common nutritional disorder in pecan trees [Carya illinoinensis (Wangenh.) C. Koch], especially in calcareous soils. This study in Chihuahua, northern Mexico, analyses the effects of zinc nutritional status on various physiological and nutritional indicators, on the metabolism of oxidative stress, and on the yield and fruit quality of pecan. The aim was to identify possible bioindicators of soil zinc deficiency. The experimental design was completely randomized with four nutritional conditions with respect to zinc: a control and three levels of zinc deficiency - slight, moderate and severe. Zinc deficiency is characterised by small leaves with interveinal necrosis and rippled leaf margins. The lowest values of leaf area, SPAD values, total N and NO3 concentration were observed under conditions of severe zinc deficiency. With worsening zinc deficiency, results indicate an increased enzymatic activity of superoxide dismutase, catalase and glutathione peroxidase. Interestingly, under severe zinc deficiency there are decreases in trunk cross-sectional area growth, in yield and in percentage kernel. Increased activity of superoxide dismutase, catalase and peroxidase enzymes is associated with detoxification of reactive oxygen species. The activity of enzymes detoxifying reactive oxygen species lessens the negative effects of zinc deficiency stress, and may be good bioindicators of zinc deficiency and its visual symptoms on pecan trees.
GC-MS Analysis, Antioxidant, Antimicrobial and Anticancer Activities of Extracts from Ficus sycomorus Fruits and Leaves
Authors: EL-BELTAGI Hossam S. , MOHAMED Heba I. , ABDELAZEEM Abdelrahman S. , YOUSSEF Reem , SAFWAT Gehan
Published: December 2018

Higher plants have been utilized worldwide as characteristic drug a long time to cure human diseases. About 80% of individuals globally use plants as safe sources of medication to cure human diseases through completely different medicine system. One of the available indigenous medicinal plants, Ficus sycomorus belongs to the Moraceae family. The plant contains totally different teams of biologically active compounds that square measure chargeable for the biological activity. Ethanolic and ethyl acetate extracts of leaves of Ficus sycomorus contain higher concentrations of total phenols, flavonoids, tannins, alkaloids and steroids than the fruit extracts. Ethanolic extract in both fruits and leaves gave higher concentrations of phytochemical compounds than the ethyl acetate extracts. Therefore, fruit and leaves extract have antioxidant and antimicrobial activity against gram positive, negative bacteria and fungus. Also, the percentage of Liver cell line (HepG2), Colorectal adenocarcinoma (Caco-2) and Breast cell line (MCF-7) viability was decreased with increasing the concentrations of the ethanolic extract of fruits and leaves of Ficus sycomorus. The high concentrations of ethanolic extract of fruits caused high reduction in the viability of cancer cells, especially in Colorectal adenocarcinoma (Caco-2) cell line. In addition, phytochemical compound screened by GC-MS method. In GC-MS analysis, 12 bioactive phytochemical compounds were identified in fruits and 29 bioactive compounds were detected in leaves extract. These totally different active phytochemicals are found to possess a good vary of activities, which can facilitate within the protection against incurable diseases.
Introduction pages
Authors: SESTRAS Radu E.
Published: December 2018

Notulae Botanicae Horti Agrobotanici Cluj-Napoca (NBHA), Issue 2, Volume 47, 2019: The papers published in this issue Vol 47 No 2 (2019) represent new exciting researches in different topics of life science, respectively in plant science, horticulture, agronomy and crop science. Among the interesting articles we invite you to find news about temporary immersion system for micropropagation of tree species and plant root hair growth in response to hormones (reviews); sexual and vegetative propagation of Hypericum empetrifolium Willd. subsp. empetrifolium; cloning and functional characterization of CsUGD2 in cucumber (Cucumis sativus L.); potential transference of CP4 EPSPS to weed species from genetically modified Gossypium hirsutum in Northern Mexico; isolation and functional characterization of an AGAMOUS-LIKE 18 (AGL18) MADS-box gene from cucumber (Cucumis sativus L.); avocado fruit pulp transcriptomes in the after-ripening process; transcriptome sequencing of two Kentucky bluegrass (Poa pratensis L.) genotypes in response to heat stress etc. Notulae Botanicae Horti Agrobotanici Cluj-Napoca journal has moved to online-only publication at the start of 2017; beginning in 2019, the journal appears quarterly. At the same time, we maintain our standard publication, as printed form, with ‘classic’ style - volume, issue, pagination.
AND/OR Search for Marginal MAP
Authors: Marinescu Radu , Lee Junkyu , Dechter Rina , Ihler Alexander
Published: December 2018

Mixed inference such as the marginal MAP query (some variables marginalized by summation and others by maximization) is key to many prediction and decision models. It is known to be extremely hard; the problem is NPPP-complete while the decision problem for MAP is only NP-complete and the summation problem is #P-complete. Consequently, approximation anytime schemes are essential. In this paper, we show that the framework of heuristic AND/OR search, which exploits conditional independence in the graphical model, coupled with variational-based mini-bucket heuristics can be extended to this task and yield powerful state-of-the-art schemes. Specifically, we explore the complementary properties of best-first search for reducing the number of conditional sums and providing time-improving upper bounds, with depth-first search for rapidly generating and improving solutions and lower bounds. We show empirically that a class of solvers that interleaves depth-first with best-first schemes emerges as the most competitive anytime scheme.
Resolução de problemas no ensino de Ciências: utilização de Artêmia salina como modelo experimental para o estudo de plantas medicinais na escola básica
Authors: Fernandes Salgueiro Andreia Caroline , Goulart Aline Silva , Viçosa Débora Lopes , Viçosa Cátia Silene Carrazoni Lopes , Folmer Vanderlei
Published: December 2018

O ensino tradicional tem recebido críticas por não preparar os estudantes para o enfrentamento de situações-problema. A metodologia de Resolução de Problemas (MRP) baseia-se em uma abordagem orientada para a investigação. Apresentamos aqui uma proposta de trabalho com a MRP aplicada ao estudo de plantas medicinais com o modelo experimental Artêmia salina. Participaram 25 estudantes do 6º e 7º anos do ensino fundamental de uma escola de baixo IDEB. A atividade foi realizada no laboratório de ciências da escola por um período de cinco dias. Os resultados indicaram que a utilização do modelo experimental aliado à MRP mostrou-se efetivo em aumentar o interesse e participação dos estudantes pela atividade. Da mesma forma, a utilização do laboratório em contrapartida à sala de aula facilitou o processo de “fazer-se cientista”. Os estudantes, ao final da atividade, demonstraram aprendizado significativo dos temas abordados, com uma perspectiva mais ampla acerca do que é Ciência e de fazer Ciência.
Ciclo celular: construção e validação de uma sequência didática pela metodologia da engenharia didática
Authors: Kieling Ketelin Monique Cavalheiro , Da Silva Goulart Aline , Roehrs Rafael
Published: December 2018

No ensino de Biologia, muitos conteúdos são complexos e abstratos se tornando um desafio para o professor ensiná-los. Diante desta problemática, se faz necessário o uso de estratégias de ensino que possibilitem a aprendizagem destes conteúdos. A elaboração de Sequências Didáticas (SD) se apresenta como uma estratégia de planejamento de aula muito empregada no ensino de Ciências, permitindo ao professor dar sentido aos conteúdos trabalhados em sala de aula. Neste sentido, constitui-se como objetivo deste trabalho a construção, aplicação e validação de uma SD voltada ao ensino do Ciclo Celular. Para tanto, a metodologia da Engenharia Didática (ED) norteou a construção da SD a partir dos conhecimentos prévios, das dificuldades e obstáculos que os estudantes enfrentam no estudo deste conteúdo e nos auxiliou na validação da SD. Por ser um método indutivo, a validação ocorreu a partir das comparações entre a análise a priori e a análise a posteriori. Os resultados da aplicação da SD foram satisfatórios e a SD foi validada.
Hakîm et-Tirmizî’nin ‘Risâletü Keyfiyyeti’s-Sülûk ilâ Rabbi’l-Âlemîn’ Adlı Eserinde Bireysel Bir Çaba Olarak Uzlet, Halvet ve Keşf Süreci
Authors: Uyar Mehmet
Published: December 2018

Hakîm et-Tirmizî’nin Risâletü Keyfiyyeti’s-sülûk adlı
eseri uzlet, halvet ve keşf kavramları etrafında şekillenir. Kavramların işaret
ettiği sürecin adı ise sülûktur. Bu çerçevede eser, sülûkun işleyiş sürecini,
gerekçe ve yöntemlerini, sülûkta sâlike rehberlik eden kavramları ele
almaktadır. Eserde, fiziksel ve psikolojik faktörler göz önüne alınarak bir
sülûk
süreci tavsiye edilmiştir. Sâlikin niyeti, sülûka başlanmasını sağlayan
düşünsel alt yapı ve devamını sağlayacak olan psikolojik ve fiziksel unsurlar
bir bütünlük içerisinde ele alınmıştır. Sâlikin hem düşüncelerini, hem ruh
halini ve hem de fiziksel durumunu kontrol altında tutması gereken bir sülûk
metnin ana yapısını teşkil etmektedir. Önemli bir husus olarak Tirmizî,
eserinde kavramları bireysel bir çabaya yönelik ele almaktadır. Tarikatlar
öncesi dönemde sülûkun anlamsal çerçevesine dair bilgiler ihtiva etmesi
açısından eser önemli bir örnek niteliğindedir. Keşfin aşamalarını ve içeriğini
canlı bir biçimde tasvir etmesi de eserin dikkat çekici bir özelliğidir. Bu makalede,
sülûk vasıtasıyla elde edilecek keşfî bilgiler Tirmizî’nin eseri çerçevesinde
ele alınacaktır.
Öğrencilerin İmam Hatip Liselerini Tercih Etme Nedenleri (Elazığ Örneği)
Authors: Özdemir Şuayip , Karateke Tuncay
Published: December 2018

Bu çalışmada, İmam Hatip
Liselerinde öğrenim gören öğrencilerin bu okulları tercih etmelerinde etkili
olan faktörlerin belirlenmesi
amaçlanmıştır. Araştırmanın amacını ortaya koyabilmek için nicel araştırma
yönteminin betimsel tarama modeli kullanılmıştır. Araştırma örneklemi
2017-2018 eğitim öğretim yılının birinci döneminin başında Elazığ merkezde
bulunan ikisi erkek, ikisi kız, biri proje okulu olmak üzere toplam beş İmam
Hatip Lisesinden rastlantısal olarak seçilen 600 öğrenciden oluşmaktadır.
Araştırmanın verileri anket yoluyla elde edilmiştir. Verilerin analizinde
betimsel istatistiklerden frekans, yüzde ve aritmetik ortalama kullanılmıştır. Araştırmada,
İmam Hatip Liselerine yönlendirici nedenler arasında en etkili faktörün “aile,
kişisel tercih ve lise tercih puanı” olduğu görülmüştür. İmam Hatip Lisesinin
tercih edilmesindeki en etkili faktörün ise “din eğitimi” faktörü olduğu tespit
edilmiştir. Fakat Proje İmam Hatip Liselerinde öğrenim gören öğrencilerin bu
okulu tercih etmesinde “okulun eğitim kalitesi”nin daha etkili olduğu
belirlenmiştir.
İslam Borçlar Hukukunda Ta‘yin Muhayyerliği
Authors: Şahin Hasan
Published: December 2018

İslam hukukunda
tarafların karşılıklı irade beyanında bulunmaları ile kurulan akidler, tam
anlamıyla hukuki sonuç meydana getirmesi ve mülkiyetin kesin bir şekilde
intikali için birtakım şartlara ihtiyaç duyar. Ayrıca bu şartlarla birlikte
tarafların yanılmasının önüne geçilmesi için akidlerde bir takım seçimlik
haklar vardır. Bu haklar “aldanmama, rızaya dayanma ve meçhuliyet taşımama”
gibi ilkelere dayanır. Bu ilkelerden hareketle akidlerde seçme, cayma ve onama
iradesinin yer aldığı her husus muhayyerlik konusu içerisinde değerlendirilir.
Tarafların ön anlaşma ile belirledikleri muhayyerliklerden olan ta‘yin muhayyerliği
kuruluş ve tamamlanma sürecinde akdin şartlarını negatif yönde etkilememekte,
mün’akid, sahih ve lazım bir şekilde kurulmuş akidde müşteriye veya satıcıya
belirli ürünlerden birisini satış sonrası seçme imkanı vermektedir. Bu seçimlik
hak, akdin nefaz kazanmasında etkilidir diyebiliriz. Muhayyerliklerin akidlerde
var oluş esprisi olan “aldanmayı önleme” ilkesi, ta‘yin muhayyerliğinde de yer
almakta olup, aldanmaktan korkan tarafa en azından tespit edilmiş olan
mallardan dilediğini seçme imkanı vermektedir. Modern kanunlarda yer almayan bu
tür bir seçimlik hakkın İslam satış hukukunda yer alması akit sistematiği
açısından değerli bir husustur.
Merhamet Eğitiminin Saldırganlık Davranışını Azaltmadaki Rolü
Authors: Genç Muhammet Fatih
Published: December 2018

Çocuklar bazen saldırgan davranırlar ve bunun nedenini tam olarak anlamak da bizim için zordur. Saldırganlığın nedenlerini açıklayan pek çok yaklaşım ve araştırmanın yanı sıra saldırganlığın nasıl azaltılacağı üzerine de çok sayıda çalışma yapılmıştır. Bu çalışma merhamet değerinin çocukların saldırganlık davranışını azaltmada etkisi olup olmayacağının anlaşılması için yapılmıştır. Benzer sosyo-demografik özelliklere sahip iki ayrı grup uygulama için seçilmiştir. Deney grubuna sekiz oturumluk merhamet eğitimi verilmeden önce ve verildikten sonra saldırganlık ölçeği uygulanmıştır. Aynı zamanda kontrol grubuna da saldırganlık ölçeği uygulanmıştır. Hem deney hem de kontrol grubunun ön-test ve son-test puanları arasındaki fark hesaplanmıştır. Deney grubunda saldırganlık puanı manidar bir şekilde azalırken, kontrol grubunda fark olmadığı tespit edilmiştir.
Kara Davud Paşa Camii İmâreti Vakfı
Authors: Sağlam Nevzat
Published: December 2018

Kaynağını Kur’an ve sünnetten alan
vakıf, Hz. Peygamberden itibaren Müslümanların adeta birbiriyle yarıştıkları
bir hizmet alanı olmuştur. Hayır, hasenat, şefkat, merhamet, yardımlaşma gibi
değerler ve duygularla yaşayan vakıflar, yüzyıllarca bir hayır müessesesi
olarak toplum hayatında sosyal, ekonomik, dini, ilmi sahalarda önemli hizmetler
görmüşlerdir. Osmanlı dönemi devlet ricalinden Kara Davud Paşa da Üsküdar’da bir
vakıf eseri olarak yaptırdığı, Camii ve imarethanesiyle ismini
ebedileştirmiştir. Ancak kendi adıyla anılan Camii halen ayakta ise de imârethane kısmı mevcut değildir. Bu
çalışmada vakfiyesi ve arşiv belgeleri ışığında Kara Davud Paşa Camii Vakfı'nın kuruluşu, idaresi, gayr-i
menkulleri ve gelirleri ele alınmaktadır.
İmam Mâtürîdî’nin Nesh Anlayışı
Authors: Karakuş Abdulkadir
Published: December 2018

Ebû Mansûr el-Mâtürîdî (ö. 333 / 944) 3-4. yüzyıllarda, Hanefî
geleneğinin devamı olarak Horasan - Maverâünnehir coğrafyasında yaşamış, Ehl-i
Sünnet inanç sisteminin önemli öncülerindendir. İmâm Mâtürîdî, kelâm ilmi
yanında tefsir ve fıkıh alanlarında vukufiyet sahibi olup, bu sahaların hemen
her birinde pek çok eser kaleme almıştır. Ancak bunlardan sadece Kitâbü’t-Tevhîd
ve Teʼvîlâtü’l-Kur’ân günümüze ulaşmıştır. Te’vîlâtü’l-Kur’ân,
tefsir alanında özellikle onun ve o gün benzer tefsir anlayışını günümüze
taşıması bakımından çok önemli olduğu gibi aynı zamanda İmâm Matürîdî’yi
tanımak açısından da mühim bir eserdir. Bu araştırmamızda, İmâm Mâtürîdî’nin Te’vîlâtü’l-Kur’ân
adlı eserinden hareketle, müellifin nesihle ilgili olan ve literatürde neshin
vaki olduğuna dair görüşlerin beyan edildiği ayetlere yaklaşımını ortaya
koymaya çalışacağız. Çünkü nesih, tefsir ilminin önemli ve tartışmalı
konularından bir tanesidir. Kur’an tefsiriyle yakından ilişkilendirilen bu konu
üzerindeki tartışmalar, ilk dönemlerden beri süregelen bir husustur. Bu önemli
konunun İmâm Mâtürîdî tarafından ne şekilde algılandığı ve tarif edildiği, o
günün nesih algısını bilmek ve günümüzde neshi nasıl algılamamız gerektiğini
tespit etmek açısından oldukça önemlidir. İmâm Matürîdî’nin, eserinde nesihten
bahsettiği malumdur; ancak bundan kastedilenin ne olduğu sorusunun cevabı çok
açık ve net değildir. Bu sebeple, bu çalışmamızda bu sorunun cevabını
netleştirmeye, o günün diğer müfessirlerinin görüşleriyle birlikte İmâm
Mâtürîdî’nin nesih anlayışını belirlemeye gayret edip, nesih hakkında bir
kanaat ortaya koymaya çalışacağız.
Dillerin Kökenine İlişkin Kelâmî Yaklaşımlar: Bâkıllânî Örneği
Authors: Çam Elmas Gülhan
Published: December 2018

Kelâm’da dillerin kökenine dair tartışmalar
genellikle Allah’ın Kelam sıfatı ve kelamullah problemi ekseninde ele
alınmaktadır. Bu tartışma ve bağlantılı diğer tartışmalar, itikadî ekollerin
kendi tercihlerini temellendirebilmeleri gayesiyle gerçekleştirilmiştir. Kelamcıların
temel referansı Kur’an’dır. Kur’an ise, okunan ve yazılan bir dil olarak Arapça
oluşu ve i‘caz gibi edebî nitelikleri nedeniyle anlambilim sınırları içinde yer
almaktadır. Kur’an’ın dile yaptığı vurgu ve dili bir otorite olarak kabul
etmesi kelamcılar tarafından önemsenmiştir. Özellikle Bâkıllânî, dilin bu
otoritesinin farkındadır ve söz konusu otoriteyi güçlü bir şekilde
kullanmıştır.
Ali b. Ma’bed el-Mısrî’ye (ö. 218/833) Nispet Edilen Bir Hadis El Yazmasının İncelenmesi
Authors: Akgün Hüseyin
Published: December 2018

Rakkalı olmakla birlikte asıl ilmi faaliyetlerini Mısır’da gerçekleştirmiş olan Hanefi âlim Ali b. Ma’bed b. Şeddâd er-Rakkî el-Mısrî (ö. 218/833) zamanımızda pek bilinmeyen bir muhaddis ve fakîhtir. Leys b. Sa’d (ö. 175/791), İsmail b. Ca’fer (ö. 180/796), İmam Muhammed eş-Şeybânî (ö. 189/805) Abdullah b. Vehb (ö. 197/813) gibi hocalardan ders alan Ali b. Ma’bed, aynı zamanda İmam Muhammed’in Câmi’u’l-kebîr ve Câmi’u’s-sağîr adlı eserlerinin de râvisidir. Kendisine nispet edilen tek eseri olan Kitâbu’t-tâ’at ve’l-ma’siye adlı kitabı da kayıp durumdadır. İşte bu araştırmamızda ona ait olduğunu düşündüğümüz, Cambridge Üniversitesi Kütüphanesi’nde “Mich.Pap.D.953” olarak kayıtlı bulunan bir papirüs üzerine yazılmış olan hadisleri değişik açılardan incelemeyi amaçladık. Söz konusu bu papirüsle N. Abbott’un Studies in Arabic literary papyri II adlı kitabında incelediği 13 numaralı papirüsün aynı eserin iki parçası olduğu sonucuna vardık. Bu bağlamda bu papirüsün söz konusu eserine mi ait yoksa, adını bilmediğimiz başka bir eserinin bir parçası mı olduğunu da araştırdık. Bir hadis cüzü/kitabı olarak doğrudan müellifi tarafından yazdırılmış olan bu eseri incelememiz hadis kitaplarının naklindeki güvenilirliğe de ışık tutacak niteliktedir. Amacımız bu çalışmayla bu yöndeki tartışmalara bir katkıda bulunmaktır.
Kaynakları İtibarıyla Ravzatu’l-ʿUḳūl’da Hikmet İçerikli Şiirlerin Farklı Kullanımı
Authors: Gültekin Aladdin
Published: December 2018

Birey ve toplumun geçmiş tecrübelerden faydalanarak
karşılaştıkları durumların üstesinden gelmeleri adına önceki kuşaklardaki bilgi
ve deneyim sahibi büyüklerin irat ettikleri hikmet, her zaman revaç görmüştür.
Bu bağlamdaki veriler, her alandaki gerek mensur gerekse de manzum eserler
vasıtasıyla geçmişten bugüne intikal ettirilmiştir. Bu yönüyle hikmet, evrensel
değerlerin önemli bir parçası kabul edildiğinden lokal ve belli zamanlara
mahkûm bir vakıa olarak değerlendirilemez. Diğer taraftan toplumlar hangi inanç
aşamalarından geçmiş olurlarsa olsunlar onların; insana, ahlaka ve bilime dair
akıl süzgecinden geçmiş deneyim ve birikimlerinin özlü sözler ile gelecek nesillere
aktarımı hususuna özen göstermiştir. Bunu sağlayacak en önemli araçlar arasında
şiir önde gelmektedir. Ancak bu süreçte hikmetlerin, özünde herhangi bir anlam
kayması olmasa da muhatabın yapısı ve aktarım tarzına göre birtakım
değişikliklerin olduğu görülmektedir. Bu çalışmada Muhammed b. Ġāzî’nin Ravzatu’l-ʿuḳūl
adlı eserinde geçen hikmet içerikli şiirlerin daha önceki kaynaklardaki
versiyonları ile karşılaştırılması ve söz konusu değişimin ortaya konulması
amaçlanmaktadır.
Türk-İslam Medeniyetinde Vakıf Müessesesi: Bayburt Örneği
Authors: Okuyan Abdurrahman
Published: December 2018

Müslüman
toplumların sosyal ve kültürel hayatında önemli rol oynayan hayır
müesseselerinin başında vakıflar gelmektedir. Toplumların inşası bağlamında
vakıflar tarihin derinliklerine ışık tutmaktadır. Dinin ana kaynaklarından
Kur’ân ve onun yaşayan hali Hz. Peygamber (s.a.v.), vakıf kurumunu teşvik
etmiştir. “Veren el alan elden üstündür” ilkesini hayat düsturu olarak
belirleyen bir medeniyete mensup olduğumuz aşikârdır. Pek çok açıdan insanî
değerlerin dumura uğradığı bir dönemde “komşusu açken tok yatan bizden
değildir” ilkesiyle hareket eden Müslüman toplumlar, vakıflar aracılığıyla bu
hasletleri canlı tutmayı başarmıştır. Çalışmada öncelikle vakıf kavramı
açıklanmaya çalışılmış, ardından tarihsel süreçte vakıf kurumu örneklerle ele
alınmıştır. Ardından Bayburt özelinde Ferruhşâd Bey Vakfı ile Bayburt Müslüman
Dilendirmezler Cemiyeti ve devamı niteliğinde 2013 yılında kurulan dernek ele alınarak
değerlendirilmiştir. Çeşitleri, muhtevaları, faaliyet alanları açısından İslam
toplumlarının vakıflara verdiği önem ve gösterdiği hassasiyet dikkat çekici
örneklerle ortaya konulmaya çalışılmıştır.
Mu’tezile ve Şîa Arasında Fikri Bağlantı Meselesi: Tevhid İlkesi Bağlamında Kâdî Abdülcebbâr ve Ebû Ca’fer et-Tûsî Arasında Bir Karşılaştırma
Authors: Korkmazgöz Rıza
Published: December 2018

Mu’tezile ve Şîa arasında fikri bağlantı meselesi, hicri dördüncü asırdan
bugüne gündemden hiç düşmemiştir. Özellikle Sünni kelamcılar Şii-İmamiyye’nin
Mu’tezili kelam düşüncesinin büyük oranda etkisinde kaldığını iddia ederken,
İmamiyye’ye mensup kelamcılar da böyle bir etkinin varlığını reddetmekte ve
kelam anlayışlarının Kur’an’a ve İmamlar’ın sözlerine dayandığını ifade
etmektedirler. Biz bu çalışmada, Mu’tezili düşüncenin bugüne nakledilmesinde
büyük payı olan Kâdî Abdülcebbâr ile gerek kelam gerekse diğer İslami ilimler
sahasında velûd bir Şii-İmamiyye âlimi olan Ebû Ca’fer et-Tûsî arasında tevhid
ilkesi üzerinden bir karşılaştırma yaparak, söz konusu tartışmaya mütevazı bir
katkı sunmayı hedefledik. Her iki mütefekkirin bizzat kendi eserleri üzerinden
yaptığımız bu karşılaştırma bize bir kısım detay ihtilaflar istisna tutulursa,
ikisi arasında tam bir mutabakat olduğunu göstermiştir.
GARPLILAŞMANIN NERESİNDEYİZ?
Authors: Doğru Rabia
Published: December 2018

Garplılaşma, yani Batılılaşma konusu, tarihten sosyolojiye, felsefeden edebiyata, mimariden müziğe birçok alanda geniş bir literatüre sahip görünmektedir. Bunun fark edebildiğimiz en belirgin sebebi, “Batılılaşma” denen sürecin/hareketin, bizim için geçmişten bu yana bir medeniyet sancısına işaret etmesidir.
Vascular endothelial growth factor (VEGF)-related polymorphisms rs10738760 and rs6921438 are not risk factors for proliferative diabetic retinopathy (PDR) in patients with type 2 diabetes mellitus (T2DM)
Authors: Sajovic Jana , Cilenšek Ines , Mankoč Sara , Tajnšek Špela , Kunej Tanja , Petrovič Daniel , Globočnik Petrovič Mojca
Published: December 2018

Vascular endothelial growth factor (VEGF) is an important regulator of angiogenesis and has been investigated as a candidate gene in a number of conditions, including diabetes and its microvascular complications (e.g., retinopathy and nephropathy). Several VEGF-related polymorphisms have been shown to contribute to nearly half of the variability in circulating VEGF levels in healthy individuals. Our aim was to assess the association between VEGF-related rs10738760 and rs6921438 polymorphisms and proliferative diabetic retinopathy (PDR) in Slovenian patients with type 2 diabetes mellitus (T2DM). We also investigated the effect of these polymorphisms on VEGF receptor 2 (VEGFR-2) expression in fibrovascular membranes (FVMs) from patients with PDR. This case-control study enrolled 505 unrelated patients with T2DM: 143 diabetic patients with PDR as a study group, and 362 patients with T2DM of >10 years duration and with no clinical signs of PDR as a control group. Patient clinical and laboratory data were obtained from their medical records. rs10738760 and rs6921438 polymorphisms were genotyped using TaqMan SNP Genotyping assay. VEGFR-2 expression was assessed by immunohistochemistry in 20 FVMs from patients with PDR, and numerical areal density of VEGFR-2-positive cells was calculated. The occurrence of PDR was 1.7 times higher in diabetic patients carrying GA genotype of rs6921438 compared to patients with GG genotype, with a borderline statistical significance (OR = 1.7, 95% CI = 1.00 – 2.86, p = 0.05). In addition, A allele of rs6921438 was associated with increased VEGFR-2 expression in FVMs from PDR patients. However, we observed no association between AA genotype of rs6921438 nor between rs10738760 variants and PDR, indicating that the two polymorphisms are not genetic risk factors for PDR.
Analysis of multidrug-resistant bacteria in 3223 patients with hospital-acquired infections (HAI) from a tertiary general hospital in China
Authors: Wang Meng , Wei Hongyan , Zhao Yaxin , Shang Linlin , Di Linlin , Lyu Chuanfeng , Liu Jun
Published: December 2018

The frequency of antimicrobial resistance has increased globally due to misuse and overuse of antibiotics, and multi-drug resistant (MDR) bacteria are now recognized as a major cause of hospital-acquired infections (HAI). Our aim was to investigate the prevalence, distribution, and antimicrobial susceptibility rates of MDR bacteria in patients with HAI from a tertiary hospital in China. We retrospectively evaluated all patients with a confirmed diagnosis of bacterial infection at a tertiary general hospital in Jining, for the period between January 2012 and December 2014. The following clinical and demographic data were collected: age, sex, specimens, treatment, microbiology results, and antibiotic resistance patterns of isolates. Bacterial identification and susceptibility testing were performed using VITEK 2 COMPACT system. We screened a total of 15,588 patients, out of which 7579 (48.6%) had an HAI. MDR showed 3223 out of 7579 isolates (42.5%). The most frequently isolated MDR bacteria in patients with HAI were extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (n = 1216/3223, 37.7%), MDR Pseudomonas aeruginosa (n = 627/3223, 19.5%) and MDR Acinetobacter baumannii (n = 588/3223, 18.2%). MDR-HAI were more common in males (2074/3223, 64.4%) and in elderly patients (≥60 years; 1196/3223, 37.1%). Sputum was the main source of MDR isolates (2056/3223, 63.8%). Patients with MDR-HAI were predominantly distributed in different types of intensive care units. MDR strains in our study showed resistance to most current antibiotics. Overall, patients with HAI infections attributed to MDR bacteria were widely distributed in our hospital. Enhanced surveillance of MDR bacteria is critical for guiding the rational use of antibiotics and reducing the incidence of HAI.
How latent viruses cause breast cancer: An explanation based on the microcompetition model
Authors: Polansky Hanan , Schwab Hava
Published: December 2018

Most breast cancer cases show a decrease in the concentration of the breast cancer type 1 susceptibility protein (BRCA1). However, only a small portion of these cases have a mutated BRCA1 gene. Although many attempts have been made to identify the reason for the decrease in BRCA1 expression in sporadic, non-heritable breast cancer cases, the cause is still unknown. In this review, we use the Microcompetition Model to explain how certain latent viruses, which are frequently detected in breast cancer tumors, can decrease the expression of the BRCA1 gene and cause the development of breast tumors.