Animal rabies situation in Sultanate of Oman (2017–2019)

Successful preventive and control measures of zoonotic diseases require updated epidemiological data. Sylvatic rabies is endemic in Oman since 1990. Studying of the prevalence of animal rabies in Oman (2017–2019) was the goal of the current study besides the clinical–histopathological investigations of rabies in different animal species. A total of 117 whole brains of different animal species from different regions of Oman were examined by fluorescent antibody test (FAT) and histopathology for rabies during 2017–2019. Sixty-four samples (54.7%) were positive for rabies by FAT. The most affected species were goat (53.1%) followed by camel (18.8%), which pose a great risk to farmers and veterinarians. Positive fox cases were (10.9%). Most confirmed cases of animal rabies were submitted from Northern regions of Oman. Rabies was reported recently in Al Wusta among wild ruminants, Central Oman. The seasonal cycle of animal rabies in Oman was year-round with the peak from December to April. The clinical signs and neuropathological findings were nearly similar in different animal species. Histopathology-positive cases had Negri bodies in pyramidal and purkinje neurons, non-suppurative encephalitis features, and neuronal degeneration and necrosis. The sensitivity and specificity of histopathological diagnosis of rabies in different animals were 76.47% and 100.00%, respectively. Finally, sylvatic rabies remains a major challenge to the public and animal health in Oman. Although of the value of histopathological diagnosis of rabies if no other technique is available, other complementary tests must be employed to confirm negative results.

     

Computed tomographic and radiographic morphometric study of cardiac and coelomic dimensions in captive blue-fronted Amazon parrots (Amazona aestiva,Linnaeus, 1758) with varying body condition scores

This study aimed to assess radiographic and tomographic cardiac parameters, including width and length of the heart, and the ratio of heart width to coelom width of blue-fronted Amazon parrots (Amazona aestiva) with varying body condition scores. Thirty-five captive birds were included in the study and were allocated into one of three groups according to their respective body condition score: lean, ideal and obese. No differences were observed among the groups with regard to radiographic and tomographic measurements. Computed tomography enabled better identification of the structures of the cardiovascular system without interference from the overlying structures of the celomatic cavity observed in radiographic images. However, radiographic examinations should still be considered the standard screening method to identify cardiac alterations, such as increased or reduced organ dimensions. Standardizing the techniques and measurements performed in this study may serve as a basis for further research in the field.     

Endothelial cells and angiogenesis in the horse in health and disease—A review

The cardiovascular system is the first functional organ in the embryo, and its blood vessels form a widespread conductive network within the organism. Blood vessels develop de novo, by the differentiation of endothelial progenitor cells (vasculogenesis) or by angiogenesis, which is the formation of new blood vessels from existing ones. This review presents an overview of the current knowledge on physiological and pathological angiogenesis in the horse including studies on equine endothelial cells. Principal study fields in equine angiogenesis research were identified: equine endothelial progenitor cells; equine endothelial cells and angiogenesis (heterogeneity, markers and assessment); endothelial regulatory molecules in equine angiogenesis; angiogenesis research in equine reproduction (ovary, uterus, placenta and conceptus, testis); angiogenesis research in pathological conditions (tumours, ocular pathologies, equine wound healing, musculoskeletal system and laminitis). The review also includes a table that summarizes in vitro studies on equine endothelial cells, either describing the isolation procedure or using previously isolated endothelial cells. A particular challenge of the review was that results published are fragmentary and sometimes even contradictory, raising more questions than they answer. In conclusion, angiogenesis is a major factor in several diseases frequently occurring in horses, but relatively few studies focus on angiogenesis in the horse. The challenge for the future is therefore to continue exploring new therapeutic angiogenesis strategies for horses to fill in the missing pieces of the puzzle.     

Absorption of potassium,sodium, calcium,and phosphorus by two date palm cultivars and the effect of Gibberellin treatment

Experiments were conducted to avaluate the K, Na, Ca, and P uptake by seedlings of two date palm (phoenix dactylifera L.) cultivars, Khedhri and Sekkeri as well as the effect of gibberellin (GA₃) treatment, Khedhri cultivar showed a typical hyperbolic curve of absorption of K,N, end low concentration of Ca (up to 5mM) but at higher Ca concentration, there seems to be another phase of absorption. Sekkeri cultivar exhibited similar but lower absorption rate of K and Ca while Na seems to be extruded at lower substrate concentration. The rate of P uptake by Sekkeri was irregular. Applied GA₃ slightly stimulate Na uptake by Sekkeri cultivar but at 10^–4M GA₃ enhancement of both Ca and P accummulation in both cultivars was observed.     

Influence of boron concentrations on some meta‐bolites of date palm and sorghum seedlings

Date palm (Phoenix dactylifera L. cv Khedhri) and sorghum (sorghum Sudan grass hybrid cv sugar Graze 11) plants were grown in vermiculite in a controlled environment and watered with a nutrient solution containing eight different concentrations of boron (B) (0 to 500 ppm), six months for date palm and four weeks for sorghum. The chlorophyll (Chl) content of the seedlings increased significantly with low concentrations of B for both date palm and sorghum, but no further significant increases were observed at higher concentrations. Generally, there was a positive correlation between B and calcium (Ca) content in the tissues of both seedlings when B concentrations were increased in the media. A negative correlation was found between B concentration in the media and the tissue content of phenolic compounds and the activity of some enzymes, such as polyphenol oxidase, IAA‐oxidase and phenylalanine ammonia‐lyase in the tissue, while there was a positive correlation in the case of peroxidase. Ribonucleic acid (RNA) increased significantly in date palm with the increase of B in the medium, but for sorghum, the increase occurred at 10–100 ppm and decreased at 300 and 500 ppm B in the media.     

Growth,sodium, and potassium uptake and translocation in salt stressed tomato

Salinity tolerance in some plant species has been related to characteristics of potassium (K) and sodium (Na) uptake and transport. Tomato (Lycopersicon esculentum Mill., cv. Rossel) plants were grown in nutrient solution to determine effects of two K levels [0.2 (low) and 2 mmol (high)] combined with 0, 100, and 200 mmol NaCl on growth, and on Na and K uptake and translocation. Net uptake rates of Na and K were determined by disappearance in the growth medium and by plant accumulation. At the low level of K in solution, salinity decreased shoot and root dry weight and leaf area. Addition of 2 mmol K ameliorated of the added NaCl effects and improved growth parameters. Salinity reduced net K uptake rates and to a lesser extent K translocation from root to shoot, which resulted in higher K shoot concentration and a lower K root concentration. The inhibitory effect of salinity on K translocation was greater with low K level in nutrient solution. Net uptake of K was dependent on K level in the growth medium. Addition of K resulted in decreases of shoot Na uptake. The translocation of Na from roots to shoots was reduced by K level in nutrient solution. These results indicate that K supply and K accumulation and regulation in plant tissue contribute to salt tolerance and growth enhancement.     

Variations in growth, survival and carbon isotope composition (delta(13)C) among Pinus pinaster populations of different geographic origins

To evaluate differences in growth and adaptability of maritime pine (Pinus pinaster Ait.), we studied growth, polycyclism, needle tissue carbon isotope composition (delta(13)C) as an estimate of water-use efficiency (WUE) and survival of seven populations at 10 years of age growing in a performance trial at a provenance test site in Escaroupim, Portugal. Six populations were from relatively high rainfall sites in Portugal and southwestern France (Atlantic group), and one population was from a more arid Mediterranean site in Spain. There were significant differences between some populations in total height, diameter at breast height, delta(13)C of bulk needle tissue, polycyclism and survival. A population from central Portugal (Leiria, on the Atlantic coast) was the tallest and had the lowest delta(13)C. Overall, the variation in delta(13)C was better explained by the mean minimum temperatures of the coldest month than by annual precipitation at the place of origin. Analyses of the relationships between delta(13)C and growth or survival revealed a distinct pattern for the Mediterranean population, with low delta(13)C (and WUE) associated with the lowest growth potential and reduced survival. There were significant negative correlations between delta(13)C and height or survival in the Atlantic group. Variation in polycyclism was correlated with annual precipitation at the place of origin. Some Atlantic populations maintained a high growth potential while experiencing moderate water stress. A detailed knowledge of the relationships between growth, survival and delta(13)C in contrasting environments will enhance our ability to select populations for forestry or conservation.     

Characterisation of sunflower root colonisation by <Emphasis Type="Italic">Phoma macdonaldii</Emphasis>

Phoma macdonaldii, the causal agent of black stem disease of sunflower (Helianthus annuus), also attacks roots and collars of the plants, resulting in early death. Totally resistant lines do not exist for infection of the aerial parts, but tolerant lines have been characterised. This paper presents a study on colonisation of a partially resistant and a susceptible sunflower line by P. macdonaldii. The fungus was transformed with a constitutively expressed reporter gene encoding the jellyfish green fluorescent protein via Agrobacterium tumefaciens, and colonisation of sunflower roots by this transformed strain was studied by various microscopy techniques including confocal and scanning electron microscopy. The results show that penetration of the fungus into the root occurred through natural fissures or through the epidermis and was similar in both lines. In contrast, the colonisation rate of the stele was reduced in the partially resistant line, and the morphology of the fungal hyphae was also affected. The effect on hyphal morphology was strongest in the stele, indicating a localised production of defence compounds in this line.     

Intraspecific diversity of common barley resistance to fungal diseases most widespread in southern Dagestan

A field assessment of a barley collection from the world gene pool for resistance to powdery mildew and leaf rust pathogen is carried out against a natural infection background. Broad intraspecific polymorphism of common barley in these traits is shown. A comparative analysis of breeding and local forms is given. The ecogeographic confinement of the traits is studied for the example of local barleys.