4,765 research outputs found
Atherosclerosis in aged mice over-expressing the reverse cholesterol transport genes
We determined whether over-expression of one of the three genes involved in reverse cholesterol transport, apolipoprotein (apo) AI, lecithin-cholesterol acyl transferase (LCAT) and cholesteryl ester transfer protein (CETP), or of their combinations influenced the development of diet-induced atherosclerosis. Eight genotypic groups of mice were studied (AI, LCAT, CETP, LCAT/AI, CETP/AI, LCAT/CETP, LCAT/AI/CETP, and non-transgenic) after four months on an atherogenic diet. The extent of atherosclerosis was assessed by morphometric analysis of lipid-stained areas in the aortic roots. The relative influence (R²) of genotype, sex, total cholesterol, and its main sub-fraction levels on atherosclerotic lesion size was determined by multiple linear regression analysis. Whereas apo AI (R² = 0.22, P < 0.001) and CETP (R² = 0.13, P < 0.01) expression reduced lesion size, the LCAT (R² = 0.16, P < 0.005) and LCAT/AI (R² = 0.13, P < 0.003) genotypes had the opposite effect. Logistic regression analysis revealed that the risk of developing atherosclerotic lesions greater than the 50th percentile was 4.3-fold lower for the apo AI transgenic mice than for non-transgenic mice, and was 3.0-fold lower for male than for female mice. These results show that apo AI overexpression decreased the risk of developing large atherosclerotic lesions but was not sufficient to reduce the atherogenic effect of LCAT when both transgenes were co-expressed. On the other hand, CETP expression was sufficient to eliminate the deleterious effect of LCAT and LCAT/AI overexpression. Therefore, increasing each step of the reverse cholesterol transport per se does not necessarily imply protection against atherosclerosis while CETP expression can change specific athero genic scenarios.39139
Serologic diagnosis of Toxoplasma gondii in swines slaughtered without inspection in Northern Brazil
Actividade sequestrante de radicais livres do medronho (Arbutus unedo L.).
O medronho e um fruto usado no fabrico de bebidas alcoólicas, geleias
e doces. A sua composição química apresenta elevados teores de açúcares,
minerais, e uma grande quantidade de compostos com actividade antioxidante
com comprovados efeitos benéficos na saúde humana. No presente trabalho
teve por objectivo avaliar a actividade antioxidante do medronho. Para tal, em
extractos metanó1icos foi quantificado o tear em fenóis totais, e a actividade
antioxidante através dos métodos do poder redutor, do efeito bloqueador de
radicais de DPPH (2,2-difenil-l-picrilhidrazilo) e do efeito sequestrante de
radicais superóxido. O tear de fenóis totais observado nas amostras de
medronho foi de 43,66±S,12 meq. de acido gálico/ g de extracto. Os valores de
EC,. obtidos para o poder redutor e para 0 efeito bloqueador de radicais
superóxido foi de, respectivamente 1,83 ± 0,18 mg/mL e 2,66 ± 1,44 mg/g de
extracto. Na avaliação do efeito bloqueador de radicais de DPPH, foi
determinado 0 valor de EC25, que correspondeu a 0,69 ± 0,33 mg/g de extracto
Efeitos de diferentes solventes e tempos na extracção de compostos antioxidantes presentes em avelãs (Corylus avellana L.)
Neste trabalho pretendeu-se estudar o efeito das condições experimentais sobre a extracção de fenóis totais presentes no miolo de avelã e na actividade antioxidante, de forma a avaliar o potencial destes frutos secos como fonte natural de antioxidantes. Foram testados três solventes (água em ebulição, metanol e acetona à temperatura ambiente) e vários tempos de contacto. Para cada situação, determinaram-se o rendimento de extracção, o teor em fenóis totais e o potencial antioxidante, avaliado pelo efeito bloqueador dos radicais livres de DPPH (2,2-difenil-1-picrilhidrazilo). Os maiores rendimentos de extracção foram obtidos para os extractos de acetona, aumentando com o tempo de contacto. Em relação aos fenóis totais, estes foram quantificados no miolo de avelã em todos os ensaios realizados, demonstrando a existência desses compostos no fruto. As maiores concentrações de fenóis totais foram obtidas com a extracção com água em ebulição (44,3+7,7 mg equivalentes de ácido gálico/g extracto) e acetona (80%) durante 24 H (36,2+8,8 mg equivalentes de ácido gálico/gextracto). Em relação à actividade antioxidante, os extractos mais eficientes (com menores valores de EC50), foram os de acetona, variando entre 1,12 e 1,53 mg/ml
Efeito do armazenamento da azeitona na qualidade de azeites elementares da Cv. Cobrançosa.
O objectivo do trabalho que se apresenta foi avaliar a influência do
armazenamento da azeitona na qualidade do azeite, uma vez que esta ainda é
uma prática usual na região de Trás-os-Montes.
O presente estudo decorreu na campanhas de 1997/1998 e 1998/1999
tendo incidido respectivamente em 4 e 5 lotes de azeitonas da Cv. Cobrançosa
que foram laborados em 3 tempos distintos (To- I dia após colheita; T7-7 dias
após colheita; T14 - 14 dias após colheita). Os parâmetros químicos avaliados
foram a acidez, o índice de peróxido, a absorvência no ultravioleta e a
resistência à oxidação. Nos azeites da campanha de 1997/1998 foram ainda
avaliados os teores em polifenóis totais e esteróis. Na campanha de 1998/1999
foi também avaliado o teor em tocoferóis.
À excepção do índice de peróxido todos os parâmetros avaliados
evidenciam diferenças significativas com o armazenamento da azeitona. Os
valores de acidez, K270' estigmasterol, eritrodiol e uvaol sofrem incrementos
com o armazenamento. Pelo contrário os valores de K232, resistência à oxidação,
polifenóis totais, -sitosterol e tocoferóis apresentaram reduções significativas
Web architecture affects the functional response of the space web-builder Kochiura aulica against Trioza erytreae in the laboratory
The “citrus greening disease” or huanglongbing (HLB) is caused by the Gram-negative
bacteria Candidatus Liberibacter spp. One vector of HLB, the African citrus psyllid Trioza erytreae
(del Guercio, 1918), was recorded for the first time in 2014, in mainland Spain, and since then, it has
spread throughout the Iberian Peninsula. Spiders could be natural enemies of T. erytreae. In this work,
we assessed the potential of a model spider species, selected according to the most abundant guild
in the field, as a natural enemy of T. erytreae. Theridiidae was the most successful family, capturing
adults of T. erytreae in the field. Kochiura aulica (Theridiidae) was selected as a model for functional
response assays in the laboratory. The effect of web-building plasticity on the functional response of
K. aulica was investigated using two types of arena. The spiders developed tubular-like or branch-like
webs according to the spatial constraints. The web architecture significantly shifted the trapping
efficiency of K. aulica. Functional responses for tubular and branch webs were both Type-II, but
more psyllid prey were captured and killed in the tubular webs than in branch webs. In addition,
significantly more psyllids survived in branch-like webs. Our results suggest that web architecture
is a key factor driving the number of captured adults of the psyllid. Space web builders could be
successful natural enemies of T. erytreae, although further research is needed to clarify the influence
of web-building plasticity on the functional response and trapping efficiency of spiders.The authors are grateful to the European Union grant, programme H2020 entitled: PREHLB:
Preventing HLB epidemics for ensuring citrus survival in Europe. H2020-SFS-2018–2 Topic
SFS-05–2018-2019–2020—new and emerging risks to plant health (Project nº 817526)—as well as to
the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds
FCT/MCTES to CIMO (UIDB/00690/2020) and Associated Laboratory SusTEC (LA/P/0007/2020).info:eu-repo/semantics/publishedVersio
Use of YOLOv5 object detection algorithms for insect detection
Climate change affects global temperature and precipitation patterns that influence the intensity and, in some cases, the frequency of extreme environmental events, such as forest fires, hurricanes and storms. These events can be particularly conducive to the increase of plant pests and diseases, which causes significant production losses. So, the early detection of pests is of the main importance to reduce pest losses and implement more safe control management strategies protecting the crop, human health, and the environment (e.g., precision in the pesticide application). Nowadays, pests’ detection and prediction are mainly based on counting insects on attacked organs or in traps by experts, but this is a costly and time-consuming task for extensive and geographically dispersed olive groves. Machine learning algorithms, using image analysis, can be used for autonomous pests’ detection and counting. In the present practical work, YOLOv5 was chosen to detect and count the olive fly adults (Bactrocera oleae Rossi), a key pest of olives. YOLOv5s architecture of YOLO’s algorithm was used to test its efficiency in olive fly detection on a mobile deployment solution. The results obtained were quite satisfactory, and the experimental results obtained have been analyzed and presented, encompassing a set of metrics such as precision, recall, and the mean average precision. This study will be extended for other pests and disease detection in future work. Also, this solution will be integrated into a web-based information and management service (with sensors and e-traps) that remotely detect the presence and severity of pest attacks.This work is financed by National Funds through the Portuguese funding agency, FCT - Fundação para a Ciência e a Tecnologia, within project .info:eu-repo/semantics/publishedVersio
Discrimination of varietal olive oils of the portuguese cultivars Cobrançosa, Madural and Verdeal based on their fatty acids composition
The fatty acid composition has been traditionally used to discriminate the
different vegetable oils and confirm their authenticity. The aim of the present study
was to check the possible use of the fatty acid profile to differentiate varietal olive
oils of the three most important cultivars in Northeast Portugal (Cobrançosa,
Madural and Verdeal). Fifteen varietal olive oils from each of the three cultivars
were collected to achieve that goal.
Fatty acids were determined, as methylesters, by HRGC. Methylesters were
prepared by transesterefication with BF3/methanol after saponification with
methanolic KOH. The fatty acid pattern was performed with a Chrompack CP9001
equipped with a split-splitless injector, a FID and a 50m x 0,25 mm i.d. fused silica
capillary column coated with a 0.19µm film of CP-Sil88 (Chrompack). The
temperatures of injector, detector and oven were 230, 250 and 185ºC, respectively.
The results as shown by two-way Anova techniques and discriminant analysis
demonstrate that C16:1c, C17:1, C18, C18:1c, C18:2cc and C18:3ccc can be used to
discriminate the origin of each of the three olive oils
Effect of olive fruit fly infestation on the quality of olive oil from cultivars cobrançosa, madural and verdeal transmontana
Olives (Olea europaea L.) from cultivars
Cobrançosa, Madural and Verdeal
Transmontana were collected separately
and divided into two different
groups according to the presence or
absence of infestation by the olive fruit
fly (Bactrocera oleae Gmel.). These two
groups were then mixed in varying percentages
to create five groups of olives
per cultivar with infestation levels: 0,
12.5, 25, 50 and 100%. Each group was
then processed to produce olive oil. The results, regarding mainly acidity, peroxide
value, and stability to oxidation,
suggest that olive fruit fly infestation
reduces the quality of the olive oil. The
effects of infestation varied according
to cultivar, but in general the total tocopherol
content was always lower at
the 100% infestation level. The oil from
cultivar Verdeal Transmontana had the
lowest tocopherol content compared to
oil from cultivars Cobrançosa and Madural,
which could explain the lower
quality of its oil
Systematics of species of the genus Akodon (Rodentia: Sigmodontinae) in southeastern Brazil and implications for the biogeography of the Campos de Altitude
http://deepblue.lib.umich.edu/bitstream/2027.42/111041/1/MP197.pd
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