1,721,103 research outputs found
Dandelion Herb: Chemical Composition and Use in Poultry Nutrition
No full textTaraxacum officinale, also known as dandelion herb, is a popular medicinal and therapeutic herb used for many years and is mostly raised in Europe, Asia, North and South America. It contains several nutrients and bioactive substances, especially the leaves and roots of this herb, which are a rich source of fiber, lecithin, choline, and micronutrients such as minerals (potassium, magnesium, calcium, zinc, etc., iron) and vitamins (A, C, K, and B-complex). The root has been commonly used for digestive and liver problems due to its stimulatory effects on the production of bile and detoxification functions. The leaves of dandelion have stimulatory functions on the
digestive system and possess diuretic effects. Furthermore, several studies have shown that dandelion leaves can enhance the growth and productivity of poultry. Various functions on the intestinal mucosa have been reported, including the effects on the architecture of villi, villus height/crypt depth ratio, and cellular infiltration. This herb also has various beneficial functions, such as immunomodulatory effects, stimulation of the digestive system and insulin activation, enhancing the metabolism of androgens, and acting as a probiotic, antiangiogenic, antineoplastic and demulcent. Moreover, the dandelion herb can treat indigestions and hepatitis B infection. Due to the lack of studies on the effects of dandelion, further research has to be conducted to exploit the medicinal properties of this herb for its beneficial health impact on humans, pet and livestock animals (e.g., poultry) nutrition
Herb and Plant-derived Supplements in Poultry Nutrition
No full textModern poultry industry faces the everlasting challenge of the growing
demand for high-quality, low-priced food without compromising general hygiene,
health, and welfare standards. To exploit optimal growth potential, antibioticsupplemented
feeds were implemented in the past decades. But later on, alternative
strategies to trigger the productive characteristics of birds were proposed, including the
use of phytochemicals. Phytobiotics are herbs and their derivatives, endowed with
many beneficial effects. Herbs and their products enhance feed intake by mitigating
intestinal damage, strengthening intestinal integrity, compensating nutritional needs for
local and general immune response, reducing the concentration of pathogenic
microflora, and preventing local inflammatory response. This form of feed
manipulation recently gained interest in the poultry sector due to the lack of side
effects, immune system modulation boosting, and stress tolerance. On the other hand,
several types of research highlighted the potentially harmful effects of some herbs and
their metabolites. This raised concerns among consumers about their safety and
implications as feed supplements or medicines. This chapter will provide insights into
phytobiotics, their role in immunity and growth, and the possible risks of herbal
supplemented feeds in the poultry sector
Antibiotic and antimicrobial feed additives
No full textSince their discovery, antibiotics have been widely used in animals to prevent or treat diseases and, after the 1950s,
as feed proficiency enhancers and growth promoters in animal farming (livestock and fish), although in smaller
amounts. For instance, antibiotics such as
oxytetracycline (OTC), aureomycin, bacitracin, penicillin, and streptomycin have been used in a quantity of
1 20 ppm (mg kg21) in combination with animal feed. If, on one side, such a “broadening” use
of antibiotics allowed an improvement in animal production, on the other side, it raised several controversial environmental
and ethical concerns. A typical example is the drawback derived from the antibiotics used in intensive fish farming for disease prevention
and treatment, which is related to water pollution due to drug residue diffusion.
It is worth noting that since the banning of antibiotics as growth promoters in the European Union and USA, with the only exception of metaphylactic and prophylactic
purposes, their use in food-producing animals strongly decreased, suggesting that the control measures taken at
country level were effective. However, there have been different pictures of these drugs’ use across
countries. For instance, polymyxins (e.g., colistin) are halved in food-producing animals in the USA, positively
impacting human hospitalizations where such drugs are the elective treatment for multidrug-resistant bacteria. On
the other hand, in the European Union, polymyxins are used more in food-producing animals than in humans. In
contrast, aminopenicillins, third- and fourth-generation cephalosporins, and quinolones are used more in humans
than in food-producing animals.
Despite the aforementioned considerations, antibiotic use increased in developing countries and is expected to rise
by 67% by 2030 worldwide. Therefore, it is reasonable to hypothesize
that such perpetrated use of antibiotics in animals is one of the leading causes of antibiotic resistance spread in the last
20 years among humans and pets.
If antibiotic withdrawal times are not respected, or the drugs are administered through injection in food-producing
animals, drug residues in foodstuffs (e.g., milk, eggs, and meat) can occur with consequent harmful effects on consumers’
and animals’ health.
Many literature reports evidenced the presence of antibiotics in foods of animal origin [milk,
cheese, honey, and meat] and pet food, shading the light also on
their toxic effects in vitro and in vivo as a consequence of their use as feed additives
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Bee pollen, from the flower to the harvest, and its potential therapeutic properties
Full text linkPollen is contained in flowers, and it is the strategic element that the gymnosperms and angiosperms have implemented
to carry out sexual reproduction. The pollen grain can have different shapes, from round to triangular, up to multilobed
shapes typical of each species. Each pollen grain is a single cell containing two male gametes. Inside we find the cytoplasm,
with the nucleus and the organelles, and externally, a coating layer that determines its resistance. Both male
gametes are involved in fertilization, resulting in the formation of a zygote and an endosperm. Pollen in angiosperms is
contained in the apical part of the stamens. In gymnosperms, pollen is produced in microcones. The stamens are filaments
with buttons in the upper part, called anthers. The anther usually contains four paired pollen sacs responsible for
producing the pollen grains. Once mature, the anther opens, and the pollen is released. The pollen, on the surface of the
anthers, appears as a powder with colors ranging from white and yellow, to the different varieties of red, brown, black,
or green, based on the botanical species, whose dimensions vary from 250 μm up to 5 μm. The female organ of the
flower is the Pistil. This organ in the larger basal part contains the ovary, where the ovules are stored.
In the apical part, we find the stigma, which, thanks to an adhesive substance, will hold the pollen, which, by opening,
will allow the pollen tube to descend into the ovary and fertilize the ovule, which will become a seed. This phenomenon
is called pollination. Self-pollination occurs in monecious plants when pollen grains
are transferred from the anther to the stigma on the same flower or an adjacent flower on the same plant. Crosspollination
occurs in diecious plants when pollen grains are carried on the stigmas of different plants. Pollination can
occur thanks to the wind as for conifers or by other vectors and is defined as anemogamous, hydrogamous, or zoogamous.
The first depends on the wind, the second on the water, and the third on animals; particularly, the one that occurs
thanks to insects is said to be entomogamous. Evolution has ensured that this union between the vegetable and animal worlds was created, and to make it even more effective, the plants have dressed their flowers in colors, scents, and sweet
nectar to attract animals and use them as vectors for the pollination. Even the choice to place the pollen on the anthers was successful as the insect to get to the
nectar must obligatorily get dirty with pollen. The passage from flower to flower will carry out the pollination service.
Bees play a role of primary importance. Bees retain blooms of the same type to best perform their task before moving on
to another. In this way, the plants ensure the species’ survival and the bees’ nectar and pollen to be used as food for the
hive. Some trees have specialized in producing flowers, fruits, and male and female genital organs so that a particular
insect can only reach them. This mutualistic relationship has allowed the creation of botanical biodiversity over time.
Even the morphology of the pollen changes according to the species it belongs to. Pollen transported
by the wind is usually small and with smooth shapes to better allow their transport.
Typically, these pollens determine allergic phenomena in humans. The pollen grains, which require entomophilous
pollination, have different shapes and sizes; externally, they are covered by a layer composed of lipids and carotenoids
called Pollenkit, which makes the grains sticky, whose purpose is to be recognized by the female part of the flower.
They can also present hooks or protrusions to better attach to pollinators. In the outer
part, the pollen grain has a layer called Sporoderma. The Sporoderma
is divided into two structures, the intina in the innermost part, which surrounds the plasmalemma, the cell with its internal
organs and has a structure made up of cellulose fibers, which offers mechanical protection against crushing. The
outermost layer is called Esina; its function is support and resistance thanks to a conformation rich in Sporopolleine,
which is highly structured and cross-linked polymer. It is divided into nexin more internally and sexin more externally. Its external morphology is typical for each species and variety. This characteristic is exploited
in palynology for the identification of the botanical origin of the pollen, which also allows the distinction of the various
kinds of honey, which, thanks to the pollen of origin, acquire typical flavors and aromas.
Other substances are present in the granule, which makes it a perfect system to survive for a long time, maintaining
its peculiarities. There may be openings on the surface, which, if circular in shape, are defined as Pores or Shots if they have an elongated shape; their task is to let the pollen tube out. They can occur on the entire surface or only in the
equatorial zone. Internally there are two nuclei whose function is to develop the seed and the fruit simultaneously.
As far as Propolis is concerned, it is not naturally present in the hive; rather, bees produce it after collecting resinous
substances from arboreal essences and are mixed with bee enzymes, pollen, and wax.
The resin plays a protective role for both floral and vegetative buds against external agents such as bacteria and
fungi, as well as an attractive purpose for the bees and all pollinating insects. Resin can be found at the bark level, and
it is produced mainly to protect the plants from infections and pathogens entry
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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