Hindlimb tissue composition shifts between the fetal and juvenile stages in the lamb

An electronic circuit for contactless detection of impedance changes in a tissue is presented. It operates on the principle of resonant frequency change of the resonator having the observed tissue as a dielectric. The operating frequency reflects the tissue dielectric properties (i.e., the tissue composition and on the tissue physiological changes). The sensor operation was tested within a medical application by measuring the breathing of a patient, which was an easy detectable physiological process. The advantage over conventional contact bioimpedance measurement methods is that no direct contact between the resonator and the body is required. Furthermore, the sensor’s wide operating range, ability to adapt to a broad range of measured materials, fast response, low power consumption, and small outline dimensions enables applications not only in the medical sector, but also in other domains. This can be extended, for example, to food industry or production maintenance, where the observed phenomena are reflected in dynamic dielectric properties of the observed object or material.

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Chronic Wasting Due to Liver and Rumen Flukes in Sheep

Animals ◽

10.3390/ani11020549 ◽

2021 ◽

Vol 11 (2) ◽

pp. 549

Author(s):

Alexandra Kahl ◽

Georg von Samson-Himmelstjerna ◽

Jürgen Krücken ◽

Martin Ganter

Keyword(s):

Fasciola Hepatica ◽

Clinical Symptoms ◽

Current Knowledge ◽

Infection Intensity ◽

Liver Parenchyma ◽

Trematode Species ◽

Helminth Infections ◽

Juvenile Worm ◽

Juvenile Stages ◽

Common Liver Fluke

Grazing sheep and goats are constantly exposed to helminth infections in many parts of the world, including several trematode species that causes a range of clinical diseases. The clinical picture of flukes is dependent upon the organs in which they develop and the tissues they damage within the respective organs. Accordingly, infections with the common liver fluke Fasciola hepatica, which, as juvenile worm migrates through the liver parenchyma for several weeks, may be associated with hepatic disorders such as impairment of carbohydrate, protein and fat metabolism, followed by chronic wasting. In contrast, the lancet fluke Dicrocoelium dendriticum, which does not exhibit tissue migration and thus does not lead to major tissue damage and bleeding, also does not lead to significant clinical symptoms. Rumen flukes such as Cotylophoron daubneyi cause catarrhal inflammation during their migration through the intestinal and abomasal epithelium during its juvenile stages. Depending on the infection intensity this may result in a range of clinical symptoms including diarrhoea, inappetence or emaciation. In this review, we aim to provide an update on the current knowledge on flukes particularly concerning the clinical relevance of the most important fluke species in sheep.

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Replicative Deformed Wing Virus Found in the Head of Adults from Symptomatic Commercial Bumblebee (Bombus terrestris) Colonies

Veterinary Sciences ◽

10.3390/vetsci8070117 ◽

2021 ◽

Vol 8 (7) ◽

pp. 117

Author(s):

Giovanni Cilia ◽

Laura Zavatta ◽

Rosa Ranalli ◽

Antonio Nanetti ◽

Laura Bortolotti

Keyword(s):

Bombus Terrestris ◽

The Body ◽

Rt Pcr ◽

Deformed Wing Virus ◽

The United Kingdom ◽

Target Organs ◽

Specific Organ ◽

Virus Localization ◽

Juvenile Stages ◽

Asymptomatic Individuals

The deformed wing virus (DWV) is one of the most common honey bee pathogens. The virus may also be detected in other insect species, including Bombus terrestris adults from wild and managed colonies. In this study, individuals of all stages, castes, and sexes were sampled from three commercial colonies exhibiting the presence of deformed workers and analysed for the presence of DWV. Adults (deformed individuals, gynes, workers, males) had their head exscinded from the rest of the body and the two parts were analysed separately by RT-PCR. Juvenile stages (pupae, larvae, and eggs) were analysed undissected. All individuals tested positive for replicative DWV, but deformed adults showed a higher number of copies compared to asymptomatic individuals. Moreover, they showed viral infection in their heads. Sequence analysis indicated that the obtained DWV amplicons belonged to a strain isolated in the United Kingdom. Further studies are needed to characterize the specific DWV target organs in the bumblebees. The result of this study indicates the evidence of DWV infection in B. terrestris specimens that could cause wing deformities, suggesting a relationship between the deformities and the virus localization in the head. Further studies are needed to define if a specific organ could be a target in symptomatic bumblebees.

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A preliminary study on the juvenile stages of Tenebrio molitor Linnaeus, 1758 (Coleoptera: Tenebrionidae) and Sphenarium purpurascens Charpentier, 1842 (Orthoptera: Pyrgomorphidae) as exploitable nutraceutical resources

International Journal of Tropical Insect Science ◽

10.1007/s42690-021-00477-9 ◽

2021 ◽

Author(s):

Arijit Ganguly ◽

Jose Manuel Pino Moreno

Keyword(s):

Tenebrio Molitor ◽

Juvenile Stages ◽

Preliminary Study ◽

Coleoptera Tenebrionidae

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Use of Pelleted Diets in Commercially Farmed Decapods during Juvenile Stages: A Review

Animals ◽

10.3390/ani11061761 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1761

Author(s):

Mohd Amran Aaqillah-Amr ◽

Ariffin Hidir ◽

Mohamad N. Azra ◽

Abdul Rahim Ahmad-Ideris ◽

Muyassar H. Abualreesh ◽

...

Keyword(s):

Feeding Behavior ◽

Optimal Growth ◽

Careful Consideration ◽

Physical Characteristics ◽

Market Demand ◽

Nutrient Requirements ◽

Natural Diet ◽

Feed Formulation ◽

Juvenile Stages ◽

Formulated Feed

The increasing market demand for decapods has led to a considerable interest in cultivating decapod species at a larger scale. Following the development of hatchery technologies, most research has focused on the development of formulated feeds for commercially farmed decapods once they enter the juvenile stages. The use of formulated feed for decapods at a commercial scale is still in the early stages. This is probably because of the unique feeding behavior that decapods possess: being robust, slow feeders and bottom dwellers, their feeding preferences change during the transition from pelagic larvae to benthic juveniles as their digestive systems develop and become more complex. The current practice of decapod aquaculture involves the provision of juveniles with food such as natural diet, live feed, and formulated feed. Knowledge of nutrient requirements enables diets to be better formulated. By manipulating the levels of proteins and lipids, a formulated feed can be expected to lead to optimal growth in decapods. At the same time, the pellet’s physical characteristics are important factors to be considered upon formulating commercially farmed decapod feeds, considering the unique feeding behavior of the decapod. However, most published studies on decapod nutrition lack data on the physical characteristics of the feed types. Thus, it is difficult to establish a standard feed formulation that focuses on the physical pellet properties. Moreover, careful consideration must be given to the feeding behavior of species, as decapods are known as bottom feeders and are robust in terms of handling feed. Information on the pellet forms, diet composition, and unique feeding behaviors in commercially farmed decapods is gathered to suggest potential better formulated diets that can optimize growth and reproduction. Thus, the purpose of this review is to summarize the information that has been published to date and to come up with suggestions on ways to improve the feed formulation in decapods that comply with their feeding behavior and nutrient requirements. Further research is needed to explore the potential of the pelleted feed at the adult stage so the decapod can take full advantage of the nutrients present in the pellets.

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Heterochrony and the Problem of Missing Links in Evolutionary Sequences

The Paleontological Society Special Publications ◽

10.1017/s2475262200004445 ◽

1984 ◽

Vol 1 ◽

pp. 84-96 ◽

Cited By ~ 1

Author(s):

Thomas W. Broadhead ◽

Johnny A. Waters

Keyword(s):

Natural Selection ◽

Feature Recognition ◽

Biological Meaning ◽

Juvenile Stages ◽

Transitional Forms ◽

Living Organisms ◽

Taxonomic Groups ◽

Organic Change

Critics of the concept of organic change through time have demanded proof not only of “transitional forms” but of specific transitions among higher taxonomic groups. Transitional forms among species and between a species of one genus and a species of another genus have been criticized because most demonstrated ancestor-descendant transitions are considered to occur within one “kind” of organism; the “kind” concept is bereft of biological meaning.Natural selection acts upon organisms at all stages of ontogeny, and especially at larval-juvenile stages. Large shifts in the morphology of one or more features are common in groups of organisms that evolve by heterochrony. Because heterochrony involves a change in timing of the appearance or development of a particular feature, recognition of heterochrony requires a confident knowledge of ontogeny. The resulting increase in complexity (e.g. recapitulation) or decrease in complexity (e.g. paedomorphosis), well documented among living organisms, commonly excludes morphologic intermediates. Paedomorphosis is especially important in the evolution of progressively simplifying lineages and has been well documented from living plants and animals and fossil representatives of echinoderms (blastoids, crinoids), conodonts, arthropods, mollusks and vertebrates. Heterochrony characterizes the evolution of most metazoan organisms, occurs at all taxonomic levels and was probably responsible for major innovations by which higher taxonomic groups are recognized.

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