Galactomannans are polysaccharides obtained from legume seed extraction. They present a chemical structure consisting of D-mannose chains linked by glycosidic bonds and galactose branches. The main ...focus lies in their use as thickeners in the food industry, aimed at improving the dielectric properties of food during heating processes within the radiofrequency and microwave ranges. In this work, the prepared galactomannan samples were electrically analyzed through impedance spectroscopy, which is a powerful physical technique. From the experimental measurements, the dielectric permittivity and loss tangent of the galactomannan solutions were analyzed and the electrical modulus formalism was used to study the dielectric relaxations. Crude galactomannans exhibited higher values of permittivity, conductivity, and losses compared to purified galactomannans. Increasing ethanol concentration in galactomannan purification causes an increase in the permittivity and conductivity of galactomannan solutions. In a 1% solution, at 1 kHz, the permittivity increased from 378.56 to 538.09, while in the 2% solution, this increase was from 656.22 to 1103.24. Regarding the conductivity, at the same frequency, the increase was from 1.6 × 10−3 to 3.3 × 10−3 Ω−1m−1 and from 2.9 × 10−3 to 5.5 × 10−3 Ω−1m−1, respectively. The rise of the ethanol concentration in galactomannan purification led to a decrease in the relaxation time, from 448.56 to 159.15 μs and from 224.81 to 89.50 μs in the solution with 1 and 2%, respectively. The results suggest that galactomannan from Adenanthera pavonina L. has potential for use in the food industry.
Abstract The combination of ethnobotanical and ecological knowledge is an important tool in indicating priority species for conservation. We sought to gather ethnobotanical knowledge on the diversity ...and use of woody medicinal plants in the Chapada Araripe region, assessing the real availability of woody medicinal resources in the Araripe Forests in the cerrado and carrasco areas, and indicate priority species for conservation. A total of 107 species were recorded in the ethnobotanical surveys, classified into 39 families and 83 genera, of which 92 species, 36 families and 70 genera for the cerrado areas, and 47 species, 25 families and 39 genera, for the carrasco areas. 59% were present in the phytosociological surveys for cerrado and 38% for carrascos. Species with high versatility of medicinal use did not necessarily have high local availability, and some were not recorded in the sampling. Thirteen species in cerrados and four in carrascos were indicated as conservation priorities. Use not aligned of species with the reality of the present time can indeed affect the vegetation landscape, and in a future scenario, not taking local measures to conserve protected forest resources, besides increasing the lists of local conservation priorities, can affect economic practices, increasing social and environmental conflicts.
Recent studies demonstrated that changes in DNA methylation (DNAm) and inactivation of two imprinted genes (MKRN3 and DLK1) alter the onset of female puberty. We aimed to investigate the association ...of DNAm profiling with the timing of human puberty analyzing the genome-wide DNAm patterns of peripheral blood leukocytes from ten female patients with central precocious puberty (CPP) and 33 healthy girls (15 pre- and 18 post-pubertal). For this purpose, we performed comparisons between the groups: pre- versus post-pubertal, CPP versus pre-pubertal, and CPP versus post-pubertal.
Analyzing the methylome changes associated with normal puberty, we identified 120 differentially methylated regions (DMRs) when comparing pre- and post-pubertal healthy girls. Most of these DMRs were hypermethylated in the pubertal group (99%) and located on the X chromosome (74%). Only one genomic region, containing the promoter of ZFP57, was hypomethylated in the pubertal group. ZFP57 is a transcriptional repressor required for both methylation and imprinting of multiple genomic loci. ZFP57 expression in the hypothalamus of female rhesus monkeys increased during peripubertal development, suggesting enhanced repression of downstream ZFP57 target genes. Fourteen other zinc finger (ZNF) genes were related to the hypermethylated DMRs at normal puberty. Analyzing the methylome changes associated with CPP, we demonstrated that the patients with CPP exhibited more hypermethylated CpG sites compared to both pre-pubertal (81%) and pubertal (89%) controls. Forty-eight ZNF genes were identified as having hypermethylated CpG sites in CPP.
Methylome profiling of girls at normal and precocious puberty revealed a widespread pattern of DNA hypermethylation, indicating that the pubertal process in humans is associated with specific changes in epigenetically driven regulatory control. Moreover, changes in methylation of several ZNF genes appear to be a distinct epigenetic modification underlying the initiation of human puberty.
This study aimed to evaluate the Brucella ovis ΔabcBA strain as a vaccine candidate in the murine model. BALB/c mice were subcutaneously or intraperitoneally immunized with a single dose or three ...doses of the B. ovis ΔabcBA strain and then were challenged with wild-type B. ovis. Single or multiple immunizations provided only mild protection, with significantly smaller numbers of wild-type B. ovis CFU in the livers of immunized mice but not in the spleens. Encapsulation of B. ovis ΔabcBA significantly improved protection against experimental challenges in both BALB/c and C57BL/6 mice. Furthermore, immunization with encapsulated B. ovis ΔabcBA markedly prevented lesions in the spleens and livers of experimentally challenged mice. These results demonstrated that the encapsulated B. ovis ΔabcBA strain confers protection to mice; therefore, this strain has potential as a vaccine candidate for rams.
Highlights • Ferric iron uptake via IroN and TonB uptake contributes to fitness of Salmonella typhimurium in the inflamed intestine. • Ferrous iron uptake via FeoB contributes to Salmonella fitness ...in the intestine after antibiotic treatment. • The benefit conferred by FeoB after antibiotic treatment is independent of T3SS-induced intestinal inflammation. • Disruption of the gut microbiota by antibiotics may alter the availability of ferrous iron to colonizing Salmonella.
Protecting riparian vegetation around streams is vital in reducing the detrimental effects of environmental change on freshwater ecosystems and in maintaining aquatic biodiversity. Thus, identifying ...ecological thresholds is useful for defining regulatory limits and for guiding the management of riparian zones towards the conservation of freshwater biota.
Using nationwide data on fish and invertebrates occurring in small Brazilian streams, we estimated thresholds of native vegetation loss in which there are abrupt changes in the occurrence and abundance of freshwater bioindicators and tested whether there are congruent responses among different biomes, biological groups and riparian buffer sizes.
Mean thresholds of native vegetation cover loss varied widely among biomes, buffer sizes and biological groups: ranging from 0.5% to 77.4% for fish, from 2.9% to 37.0% for aquatic invertebrates and from 3.8% to 43.2% for a subset of aquatic invertebrates. Confidence intervals for thresholds were wide, but the minimum values of these intervals were lower for the smaller riparian buffers (50 and 100 m) than larger ones (200 and 500 m), indicating that land use should be kept away from the streams. Also, thresholds occurred at a lower percentage of riparian vegetation loss in the smaller buffers, and were critically lower for invertebrates: reducing only 6.5% of native vegetation cover within a 50‐m riparian buffer is enough to cross thresholds for invertebrates.
Synthesis and applications. The high variability in biodiversity responses to loss of native riparian vegetation suggests caution in the use of a single riparian width for conservation actions or policy definitions nationwide. The most sensitive bioindicators can be used as early warning signals of abrupt changes in freshwater biodiversity. In practice, maintaining at least 50‐m wide riparian reserves on each side of streams would be more effective to protect freshwater biodiversity in Brazil. However, incentives and conservation strategies to protect even wider riparian reserves (~100 m) and also taking into consideration the regional context will promote a greater benefit. This information should be used to set conservation goals and to create complementary mechanisms and policies to protect wider riparian reserves than those currently required by the federal law.
Resumo
Proteger a vegetação no entorno de riachos é vital para reduzir os efeitos das mudanças ambientais sobre os ecossistemas aquáticos e para a manutenção de sua biodiversidade. Assim, a identificação de limiares ecológicos é útil para regular os limites de uso e para orientar o manejo de zonas ripárias, visando a conservação da biota aquática.
Usando dados de peixes e invertebrados aquáticos de pequenos riachos do Brasil, nós estimamos os limiares de perda de vegetação nativa nos quais ocorrem mudanças abruptas na ocorrência e abundância de bioindicadores aquáticos. Também testamos se existem respostas congruentes entre os diferentes biomas, grupos biológicos e áreas de vegetação ripária (buffers).
Os valores médios dos limiares de perda de vegetação nativa variaram marcadamente entre biomas, tamanhos de buffer e grupos biológicos: entre 0,5% e 77,4% para peixes, entre 2,9% e 37,0% para invertebrados aquáticos e entre 3,8% e 43,2% para um subconjunto de invertebrados aquáticos. Os intervalos de confiança dos limiares foram amplos, mas os valores mínimos dos intervalos foram reduzidos para os menores buffers ripários (50 e 100 m) em comparação com os maiores (200 e 500 m), indicando que o uso do solo deve ser mantido longe dos riachos. Além disso, os limiares ocorreram em menores porcentagens de perda de vegetação ripária nos buffers menores, e foram criticamente baixos para invertebrados aquáticos: uma redução de apenas 6,5% da cobertura de vegetação nativa no buffer ripário de 50 m é suficiente para ultrapassar os limiares de perda de invertebrados.
Síntese e aplicações. A elevada variabilidade dos limiares de declínio abrupto da biodiversidade aquática em resposta a perda de vegetação ripária nativa sugere cautela no uso de uma largura única de proteção ripária para ações de conservação e definição de políticas nacionais. Os bioindicadores mais sensíveis podem ser usados como sinais precoces que alertam a aproximação de mudanças abruptas na biodiversidade aquática. Na prática, manter reservas ripárias (áreas de preservação permanente—APP) de pelo menos 50 m de largura, em ambos os lados dos riachos, parece ser mais efetivo em proteger a biodiversidade de água doce do Brasil. Contudo, incentivos e estratégias de conservação que protejam reservas ripárias ainda maiores (~100 m de largura) e que levem em consideração o contexto regional podem promover um maior benefício. Essas informações podem ser usadas para definir metas de conservação e para criar mecanismos e políticas complementares para proteger reservas ripárias (APP) ainda maiores do que aquelas atualmente requeridas pela lei federal.
The high variability in biodiversity responses to loss of native riparian vegetation suggests caution in the use of a single riparian width for conservation actions or policy definitions nationwide. The most sensitive bioindicators can be used as early warning signals of abrupt changes in freshwater biodiversity. In practice, maintaining at least 50‐m wide riparian reserves on each side of streams would be more effective to protect freshwater biodiversity in Brazil. However, incentives and conservation strategies to protect even wider riparian reserves (~100 m) and also taking into consideration the regional context will promote a greater benefit. This information should be used to set conservation goals and to create complementary mechanisms and policies to protect wider riparian reserves than those currently required by the federal law.
This study aimed to evaluate protection induced by the vaccine candidate B. ovis ΔabcBA against experimental challenge with wild type B. ovis in rams. Rams were subcutaneously immunized with B. ovis ...ΔabcBA encapsulated with sterile alginate or with the non encapsulated vaccine strain. Serum, urine, and semen samples were collected during two months after immunization. The rams were then challenged with wild type B. ovis (ATCC25840), and the results were compared to non immunized and experimentally challenged rams. Immunization, particularly with encapsulated B. ovis ΔabcBA, prevented infection, secretion of wild type B. ovis in the semen and urine, shedding of neutrophils in the semen, and the development of clinical changes, gross and microscopic lesions induced by the wild type B. ovis reference strain. Collectively, our data indicates that the B. ovis ΔabcBA strain is an exceptionally good vaccine strain for preventing brucellosis caused by B. ovis infection in rams.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This study aimed to investigate dentin wettability and surface morphology after selective removal of carious lesion by erbium‐doped yttrium aluminum garnet (Er:YAG) laser, followed by dentin ...biomodification with carbodiimide (EDC) and chitosan (CHI). Seventy‐eight bovine dentin specimens were submitted to caries induction. Specimens were distributed according to methods of carious removal (n = 39): bur at low‐speed (40,000 rpm) or Er:YAG laser (noncontact mode, 250 mJ/pulse and 4Hz). All specimens were etched with 35% phosphoric acid, and subdivided according to dentin biomodification (n = 13): Control (no biomodification), EDC or CHI. The contact angle (n = 10) between adhesive system (3M ESPE) and dentin surface was measured by a goniometer. Eighteen specimens (n = 3) were analyzed by scanning electron microscopy. Data were analyzed by two‐way ANOVA and Tukey's test (α = .05). The method used to remove carious lesion did not influence the wettability of dentinal surface (p = .748). The angles produced on the remaining dentin after biomodification were influenced (p = .007). CHI promoted higher contact angles (p = .007) and EDC did not differ from the control group (p = .586). In the bur‐treated group, most tubules were open, regardless of which biomodifier was used. Laser modified the organic matrix layer. CHI promoted partially closed tubules in some areas while EDC exposed dentinal tubules. Regardless of which method was used for selective removal of carious lesion, biomodification with EDC did not affect the dentin wettability, whereas CHI changed the wettability of remaining dentin. Both biomodifiers promoted a slight change on dentin morphology.
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