Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

Serological Evidence of Bluetongue Virus Antibodies in Sheep and Goats at Two Rearing Regions of North Somalia

To determine the presence and prevalence of bluetongue virus infection in sheep and goats at different geographical regions of North Somalia, a competitive enzyme-linked immune-sorbent assay (cELISA) for the detection of serum antibody against BTV in clinically healthy sheep and goats was carried out in Northern Somalia in two main districts of sheep and goats-rearing regions namely, Togdheer, and Waqoyi Galbed in the period between July 2008 to April 2009. Results for bluetongue infection, herd size, and herd location, mixing with other animal species with various other associations were detected among demographic, husbandry and disease variables. All animals tested were apparently normal without showing clinical signs and without history of any specific clinical signs for BTV infection. Out of 24 (601) sheep/herds investigated, 3 (12.5%) herds were seronegative and 21 (87.5%) were seropositive by cELISA with seroprevalence on herd level ranged from 4.2 % - 42.9 % with a total seroprevalence of both districts 21.8% (n=131). Out of 24 (466) goat/herds investigated, 8 (33.3%) herds were seronegative and 16 (66.7%) were seropositive by cELISA to BT virus infection with seroprevalence ranged from 12.5 % - 38.5 % on herd level with a total district seroprevalence of 16.0 % (n=77). The results of the present investigation indicate that the bluetongue virus exists within the sheep and goat herds. The findings suggest that the disease is widely distributed in most investigated parts of the North Somalia where possible insect vectors may prevail and may suggest disease endimicity which is probably subclinical or in-apparent in sheep and goats of North Somalia. The prevalence differed significantly between herd types but did not show a geographical trend. The results presented here may record the first confirmation of bluetongue virus (BTV) antibody in sheep and goats in North Somalia

Prevalence of Enzootic Bovine Leukosis (EBL) in the Northern Somalia

In the present study, a commercial immuno enzymatic assay (blocking- ELISA), were used to detect BLV antibodies in bovine serum using two monoclonal antibodies against the viral gp51 from bovines of two major districts namely, Waqoyi Galbed, and Togdheer of northern Somalia (Somaliland). Out of 468 tested cows collected from 20 herds, 1.5 % was found affected by Enzootic Bovine Leucosis (EBL) reacted positively to blocking-ELISA. On herd level, out of 20 herds tested, 6 (30.0%) were seropositive. On animal level, according to age groups tested, out of 91 tested sera aged from 2y-5y, 2.2% (n=2) animals were seropositive, while out of 259 bovine sera tested aged from 5y-8y, 1.7% (n=5) animals were seropositive. Prevalence on district level, in Waqoyi Galbed, out of 204 tested cows from 9 herds, 1.47% (n=3) animals were found seroreactive, and on herd level, out of 9 herds tested, 2 herds (22.2%) were seropositive and 7 (77.8%) were seronegative. In Togdheer, out of 264 tested cows from 11 tested herds, 4 (1.52%) animals were found seropositive, and on herd level out of the 11 herds tested 4 herds (36.4%) were seropositive and 7 (63.6%) were seronegative. This paper reports the first serological evidence of EBL virus infection in dairy cows in the Somaliland investigated regions

A seroprevalence study of ovine and caprine brucellosis in three main regions of Somaliland (Northern Somalia)

A random survey to study the seroprevalence of ovine and caprine brucellosis was carried out between July 2008 and January 2009 in three main districts of arid and semiarid rearing regions of Somaliland. A total of 1938 sheep, and 1344 goats’ blood sera were randomly collected from 42 herd/flock of accessible unvaccinated sheep andgoats to be analyzed. Rose Bengal Plate Test (RBPT) and indirect ELISA (I-ELISA) were used to screen all serum samples. At herd level, for sheep, a total 42 herd/flocks were examined, out of which, 2 (4.8%) were seronegative while 40 (95.2%) were seropositive by I-ELISA, 10 (23.8%) were seronegative and 32 (76.2%) seropositive by RBPT. Atherd level, for goats, a total 42 herd/flocks were examined, out of which, 6 (14.3%) were seronegative while 36 (85.7%) were seropositive by I-ELISA, 11 (26.2%) were seronegative and 32 (73.8%) seropositive by RBPT. A non significant seroprevalence differences were found at herd level between the three studied districts. There was no significant difference in the prevalence of brucellosis between the different studieddistricts. This study throws a strong light on that sheep and goats should be included in a national program for control and eradication of brucellosis in Somaliland. Further epidemiological studies and identification of the Brucella biotypes involved is recommended

A serosurvey of Bovine Brucellosis in three cattle-rearing regions of Somaliland (Northern Somalia)

A random survey to study the seroprevalence of bovine brucellosis has been carried out between July 2008 and December 2008 in three main districts of Somaliland (Awdal, Waqoyi Galbed and Togdheer) of northern Somalia. A total of 1668 bovine blood sera were randomly collected from 46 herd/flock of accessible unvaccinated male andfemale cattle to be analyzed. Rose Bengal Plate Test (RBPT) and indirect ELISA (I-ELISA) were used to screen all sera samples. The prevalence of brucellosis in the tested bovine sera were 5.5% (n=91), and 4.4% (n=74) by RBPT, and by I-ELISA respectively. There was a little difference regarding to sex of the prevalence between males andfemales in the overall studied districts as it was 5.0% and 3.8% in males by RBPT and I-ELISA respectively, while it was 5.8% and 5.0% in females respectively. There were little differences in prevalences of brucellosis among the studied districts which was highest in Awdal (6.5%) whereas in Waqoyi Galbeed (5.1%) and in Togdheer (5.5%) byRBPT, while it was in (5.1%), followed by Waqoyi Galbeed (4.1%), and Togdheer (4.1%) regions by (I-ELISA). There was no significant  difference in the seroprevalence according to the age

A priori testing of sparse adaptive polynomial chaos expansions using an ocean general circulation model database

This work explores the implementation of an adaptive strategy to design sparse ensembles of oceanic simulations suitable for constructing polynomial chaos surrogates. We use a recently developed pseudo-spectral algorithm that is based on a direct application of the Smolyak sparse grid formula and that allows the use of arbitrary admissible sparse grids. The adaptive algorithm is tested using an existing simulation database of the oceanic response to Hurricane Ivan in the Gulf of Mexico. The a priori tests demonstrate that sparse and adaptive pseudo-spectral constructions lead to substantial savings over isotropic sparse sampling in the present setting