Diseases associated with hypercobalaminemia in dogs in United Kingdom: A retrospective study of 47 dogs

Cobalamin concentration is often assessed in clinical practice but little is known about the significance of hypercobalaminemia. The objective of this retrospective study was to identify the conditions associated with hypercobalaminemia in dogs and to investigate association with clinicopathological variables. Medical records of dogs having serum cobalamin measured between 2016 and 2018 were reviewed. One hundred sixty dogs were included and 47 (29%) showed hypercobalaminemia. Dogs with hypercobalaminemia had gastrointestinal (57%), hepatic (11%), neurological (11%), endocrine (9%), renal (4%), pancreatic (2%), and miscellaneous (6%) diseases. Overall, 11% had neoplasia. This distribution was not significantly different from that for hypocobalaminemic and normocobalaminemic dogs. There were significantly more dogs with hyperfolatemia in the hypercobalaminemia group. These results suggest that in clinical practice hypercobalaminemia is commonly identified in gastrointestinal and hepatic disease in dogs, but can also be seen with endocrine and neurological conditions. The frequency of hyperfolatemia alongside hypercobalaminemia may reflect common metabolic pathways.     

Analysis of amino acid uptake and translocation in Arabidopsis with a low‐cost hydroponic system

In soils, amino acids may be an important source of nitrogen for plants, at least in those where organic matter is not quickly degraded. The physiology of uptake of amino acids by roots was mainly studied in the 70's and 80's, before genes encoding amino acid importers were cloned in the 90's. While two families of amino acid transporters have been identified, yielding a total of about 100 genes, the role of each member is yet to be elucidated. As a tool for studying the role of amino acid transporters from Arabidopsis we set up a new hydroponic system suitable for radioisotope use. This system enables reproducible amino acid uptake by roots and estimation of the transport to the shoots of the amino acid taken up. We show that the rates of glutamine (Gln) uptake by wild‐type roots and transfer to the shoots were linear, and that other tested amino acids were translocated to the shoots with lower efficiency than Gln. A T‐DNA insertion mutant for a Gln exporter was compared to the wild‐type plants. Gln uptake and transfer were similar in both genotypes, showing that the suppression of the exporter did not affect uptake or transfer of amino acids to the shoots. The main advantage of the hydroponic system presented here is that all the materials used to grow Arabidopsis are virtually free and can therefore be discarded, a useful feature when working with radioactivity.     

Mutualism between euryhaline tilapia Sarotherodon melanotheron heudelotii and Chlorella sp.—Implications for nano-algal production in warmwater phytoplankton-based recirculating systems

The West-African euryhaline tilapia, Sarotherodon melanotheron heudelotii shift from visually feeding on zooplankton when juveniles to mostly filter feeding on phytoplankton when adults. When reared using an appropriate ration in intensive aquaculture systems, S. m. heudelotii also consume algal-based detritus, and contribute to sediment mineralization, clean up their environment, and ultimately stimulate and sustain algal growth. We analysed such practical advantages for phytoplankton-based recirculating systems, using S. m. heudelotii and Chlorella sp. as biological material originating from the prototype of such a system operated in Senegal. We performed a 24-h factorial design experiment in 36 tubs, cross-classifying three levels of S. m. heudelotii (fishless control, unfed fish, and fed fish) with four levels of Chlorella initial density.Chlorella overall mean density increased significantly from fishless, to unfed fish, and fed fish treatments, and with Chlorella initial density. S. m. heudelotii did not alter nitrogen nor phosphorus concentrations, only affected by algal initial densities. Most ammonia excreted by fish was probably uptaken by Chlorella. Bacteria-mediated diurnal nitrification was possibly an alternative ammonium loss mechanism at highest oxygen concentrations. Algae were not limited by nitrogen or phosphorus but most likely by low dissolved organic carbon availability. Chlorella differential responses with fed vs. unfed Sarotherodon suggest that CO₂ supplied by heterotrophic S. m. heudelotii respiration played a key role. Observed Chlorella growth rates were similar to the highest rates obtained in algal mass cultures, enriched with CO₂, nitrate and phosphate, under artificial lighting.Our results suggest the existence of a Sarotherodon-Chlorella mutualism in our systems, where S. m. heudelotii provide CO₂, the major limiting factor of Chlorella growth, whereas Chlorella oxygenate and detoxify the water media from ammonia, promoting S. m. heudelotii production. This mutualism could be used to optimize photosynthetic suspended-growth aquaculture systems, particularly in the Tropics where light is abundant and temperature is continuously high.     

Using operating area size and adjacency constraints to mitigate the effects of harvesting activities on boreal caribou habitat

Context

Sustained timber harvesting conflicts with the long-term viability of boreal caribou (Rangifer tarandus caribou) populations. The spatial arrangement of harvest blocks in the landscape could mitigate the impact of logging on caribou populations. For the forest industry, however, these measures represent constraints that reduce the annual allowable cut (AAC).

Objective

Estimate the long-term impacts of spatial constraints to harvesting, applied alone or in combination, on AAC and boreal caribou populations.

Methods

We divided a 30,000 km² region into 20 harvest block sizes varying from 50 to 1000 km², and modeled the implementation of spatially explicit harvest schedule plans in combination with wildfire and caribou population dynamics. We then evaluated the probability of persistence of boreal caribou populations.

Results

The probability of maintaining an AAC target declined with increasing target AAC, increasing size of operating area, and increasing adjacency constraints. In contrast, the probability of maintaining caribou populations declined with increasing AAC, decreasing size of operating areas, and decreasing adjacency constraints. An increase in operating area size from 50 to 300 km² produced a considerable gain in AAC for all adjacency constraints.

Conclusions

Because adjacency constraints led only to a small increase in the probability of maintaining caribou populations, we recommend adopting less constraining landscape management actions, such as a 70-year period between two consecutive harvests in the same ~300-km² operating area.

     

Argan Oil Element Content is a Powerful Marker of the Quality of the Fruit Used for its Preparation

Plant Foods for Human Nutrition - Argan oil is prepared by cold pressing argan kernels collected from fully ripe fruit. Argan oil market price is particularly elevated. Consequently, efficient...     

Complete Larval Development of the Fresh Water Prawn Macrobrachium vollenhovenii in Cameroon

The African River prawn Macrobrachium vollenhovenii is the largest of the local Palaemonidae prawns along the Cameroonian coast and an important target species for fisheries and aquaculture. A preliminary study on larviculture of this species was carried out at the IRAD-AQUASOL hatchery in Kribi, Cameroon. Berried females M. vollenhovenii were obtained from the Lobe and Lokoundje Rivers in the Southern Region, typical Lower Guinea rainforest streams. The larval rearing system consisted of a single recirculation system of four 65 L cylindrical plastic containers connected to a submerged biological filter container (65 L). Experiments were conducted three times in the same condition, with two batches of larvae reared separately in duplicate per experiment, at a density of 40/L, temperature 26°C, and salinity 16%. Larvae were fed from 1 day after hatching until metamorphosis to postlarvae (PL) with newly hatched Artemia nauplii, three times daily at the rate of 5 nauplii per mL water. The number of newly hatched larvae per female body weight unit was not affected by the female size and ranged between 531 to 1349 larvae g^?1. The six batches succeeded from hatching to metamorphosis, and the 11 distinct larval stages described for M. rosenbergii were found. Larvae in all the batches developed more or less at the same pace up to stage V. However, a clear difference in the timing of appearance of the developmental stages was observed between batches and individuals of the same batch during the subsequent stages. The transition from stage V to stage VI and from stage IX to stage X was longer than the passage to other stages and seems to be the critical rearing period of M. vollenhovenii. From day 20 onward to sampling, the larval stage index (LSI) showed that larval development of the batch 1 was significantly faster than for all other batches. The time for first appearance of postlarvae was variable between batches (41–74 days), and batch 1 larvae passed through metamorphosis within a shorter span of time (41 days). Survival up to postlarvae was variable among batches, ranging between 3%–9%, and was better in batch 1 (9.31 ± 1.09). The general poor performance in terms of survival and metamorphosis rates of larvae seems to be related to the wild condition of broodstock. To improve performance of larvae, domestication of stock may be necessary. This result is the first recorded success in larviculture of M. vollenhovenii in Cameroon.     

Induction of Defense Gene Expression and the Resistance of Date Palm to Fusarium oxysporum f. sp. Albedinis in Response to Alginate Extracted from Bifurcaria bifurcata

In many African countries, the Bayoud is a common disease spread involving the fungus Fusarium oxusporum f. sp. albedinis (Foa). The induction of plant natural defenses through the use of seaweed polysaccharides to help plants against pathogens is currently a biological and ecological approach that is gaining more and more importance. In the present study, we used alginate, a natural polysaccharide extracted from a brown algae Bifurcaria bifurcata, to activate date palm defenses, which involve phenylalanine ammonia-lyase (PAL), a key enzyme of phenylpropanoid metabolism. The results obtained showed that at low concentration (1 g·L⁻¹), alginate stimulated PAL activity in date palm roots 5 times more compared to the negative control (water-treated) after 24 h following treatment and 2.5 times more compared to the laminarin used as a positive stimulator of plant natural defenses (positive control of induction). Using qRT-PCR, the expression of a selection of genes involved in three different levels of defense mechanisms known to be involved in response to biotic stresses were investigated. The results showed that, generally, the PAL gene tested and the genes encoding enzymes involved in early oxidative events (SOD and LOX) were overexpressed in the alginate-treated plants compared to their levels in the positive and negative controls. POD and PR protein genes selected encoding β-(1,3)-glucanases and chitinases in this study did not show any significant difference between treatments; suggesting that other genes encoding POD and PR proteins that were not selected may be involved. After 17 weeks following the inoculation of the plants with the pathogen Foa, treatment with alginate reduced the mortality rate by up to 80% compared to the rate in control plants (non-elicited) and plants pretreated with laminarin, which agrees with the induction of defense gene expression and the stimulation of natural defenses in date palm with alginate after 24 h. These results open promising prospects for the use of alginate in agriculture as an inducer that triggers immunity of plants against telluric pathogens in general and of date palm against Fusarium oxysporum f. sp. albedinis in particular.