Seroprevalence and risk factors for Trypanosoma evansi, the causative agent of surra, in the dromedary camel (Camelus dromedarius) population in Southeastern Algeria.

Surra, caused by Trypanosoma evansi, is a re-emerging animal trypanosomosis, which is of special concern for camel-rearing regions of Africa and Asia. Surra decreases milk yield, lessens animal body condition score and reduces market value of exported animals resulting in substantial economic losses. A cross-sectional seroprevalence study of dromedary camels was conducted in Algeria, and major risk factors associated with infection were identified by collecting data on animal characteristics and herd management practices. The seroprevalence of T. evansi infection was determined in sera of 865 camels from 82 herds located in eastern Algeria using an antibody test (card agglutination test for Trypanosomiasis - CATT/T. evansi). Individual and herd seroprevalence were 49.5% and 73.2%, respectively, indicating substantial exposure of camels to T. evansi in the four districts studied. Five significant risk factors for T. evansi hemoparasite infection were identified: geographical area, herd size, husbandry system, accessibility to natural water sources and type of watering. There was no association between breed, sex or age with T. evansi infection. Results of this study provide baseline information that will be useful for launching control programmes in the region and potentially elsewhere.

Genetic Variation in Damaged Populations of Pistacia atlantica Desf.

The Atlas Pistachio tree, Pistacia atlantica Desf., has great importance in the ecological landscape of North Africa, due to its adaptive plasticity, as well as its use as a rootstock in the cultivation of the economically important species, Pistacia vera L. The conservation and valuation of this species require sampling and an assessment of its genetic variability. For the first time in North Africa, the inter-simple sequence repeats (ISSR) molecular marker has been used in genetic-diversity assessment and in the population relationships of P. atlantica subsp. atlantica. The ISSR markers tested showed 74.1% polymorphism, while molecular variance (AMOVA) analysis revealed a high percentage of the total genetic diversity of 55.7% among the four populations studied. Cluster analysis with neighbor-joining (NJ) and principal coordinate analysis (PCO) divided the study sites into four distinct groups according to their geographical locations (Tiaret, Batna, Djelfa, and Bechar). Isolation by distance or Mantel test gave a positive correlation of r = 0.86 between geographical and genetic distances. The results in this study indicate an absence of gene flow, implying that conservation efforts should be taken separately for each population.

Phenolic constituents and antioxidant activity of Euphorbia retusa Forssk.

The aim of the present study was to evaluate the phenolic contents in capsule and root methanolic extracts of Euphorbia retusa followed by identification of phenolic on capsule extracts through high-performance liquid chromatography (HPLC- DAD) for the first time. Likewise, the antioxidant activity of both extracts was investigated by using Cupric reducing antioxidant capacity (CUPRAC). The result implies that E. retusa capsules have the highest phenolic and flavonoid contents with 105.33 ± 7.75 µg GAE.mg-1 extract 19.95 ± 0.96 µg QEs.mg-1 extract; respectively and the highest activity in CUPRAC assay with epigallocatechin 3-O-Gallate was the major flavonoid. Thus, our findings indicate that E. restusa capsules may be valorized in industrial fields.

Concentration, Distribution, and Potential Aquatic Risk Assessment of Metals in Water from Chott Merouane (Ramsar Site), Algeria.

In this study, 28 surface water samples were collected from eight different sites throughout the Chott Merouane. Samples were detected by atomic absorption spectrometry for Cd, Co, Cr, Cu, Fe, Ni, Mn, Pb, and Zn. The dissolved metal concentrations (mg/L) ranged from 0.05 to 0.90 mg/L for Cd, 0.13-6.45 mg/L for Co, bDL-2.05 mg/L for Cr, 0.03-0.27 mg/L for Cu, 0.34-7.41 mg/L for Fe, 01.6-4.54 mg/L for Ni, 0.15-1.19 mg/L for Mn, 0.23-5.88 mg/L for Pb, and 0.01-0.28 mg/L for Zn. Compared with U.S. EPA standards and other freshwaters worldwide, the most mean concentration of metals in surface water of this salt lake are higher than the guideline levels of aquatic life. This was further corroborated by results from the water quality indices that Chott Merouane is seriously polluted by metals. The values of the metal pollution index indicated that metal pollution level was Cd > Pb > Ni > Fe > Cr > Cu > Mn > Zn, and those metals belong to moderate or high pollution level. The Nemerow pollution index further indicated that Chott Merouane was suffering from serious metal contamination. Based on geostatistics analyses, generally distributions of these metal contents decreased in the order of the North Chott Merouane ≈ the Northwest Chott Merouane > the Eastern part of Chott Merouane > the South Chott Merouane. The quality of water has drastically deteriorated due to the mixed source of anthropogenic inputs. Therefore, necessary conservation and management measures should be taken to improve the water quality of this Ramsar wetland.

How do newly matured vessels start conducting water? The significance of lateral pathways for connecting newly matured vessels to the transpiration stream.

Despite the long history of research on xylem structure and function, there are no reports in the literature explaining how xylem vessel elements began conducting water just after their maturation. This study was conducted to demonstrate the anatomical arrangement of newly matured vessels, looking specifically for the first pathways connecting newly matured vessels to the transpiration stream. Using the developing stems of Paraserianthes lophantha (Willd.) I.C.Nielsen as the experimental system, the course of vessel differentiation and maturation along the developing bundles was followed by using the dye-pressure method. Water pathways from newly matured vessels to other functioning vessels were directly visualized by the technique of single-vessel dye injection. Some isolated newly matured vessels from the transpiration stream were detected using two apoplastic tracers. The results of this study converge to support the hypothesis that the movement of water in the newly matured vessels depends completely on lateral contacts with other functioning vessels via vessel-to-vessel paths or vessel relays. In cases where the lateral pathways were absent, the flow within the newly matured vessels was substantially blocked resulting in a significant hydraulic isolation of the newly matured vessels. These results might contribute to a better understanding of the pattern of water movement within the developing xylem systems, and underscore that xylem vessels start conducting water through lateral transport, although their primary function is the axial transport.

Human Health Risks Associated with Metals from Urban Soil and Road Dust in an Oilfield Area of Southeastern Algeria.

Hassi Messaoud town is a recent city that is situated inside the oil field, which hosts an important petroleum extraction field and refinery. Large-scale and long-term oil refinery and corresponding industrial activities may contaminate the surrounding soil/dust and could lead to pollution levels that can affect human health. The soil and road dust samples were analysed for different trace elements: copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn). Geo-accumulation index (I(geo)), pollution index (PI), and integrated pollution index (IPI) were calculated to evaluate the heavy metal contamination level of urban soil and road dust. The I(geo) values indicate unpolluted to moderate polluted of investigated metals in the soil samples. The assessment results of PI support the results of I(geo), and IPI indicates heavy metals in road dust polluted seriously. The noncarcinogenic health risk assessment shows that ingestion of soil/dust particles is the route for exposure to heavy metals, followed by dermal adsorption. The human exposure risk assessment based on different exposure pathways showed that the hazard index (HI) was <1.0 for all of the elements. The relative exposure risk (noncarcinogenic) was greater for toddlers. Although the overall risk was within the acceptable limit of 1.00, the HI of Pb from the soil (0.103) and road dust (0.132) was close to the threshold limits, which over the long-term may pose a health risk.

Evaluation of antioxidant activities of the edible and medicinal Acacia albida organs related to phenolic compounds.

This study compared phenolic contents and antioxidant activity in different organs of Acacia albida (leaves and bark) and focuses on identification of phenolic compounds of leaves by HPLC-DAD. The analysed organs exhibited differences in total polyphenol contents (100 and 59.5 mg GAE g(-1) DW). Phenolic contents of leaves were two times higher than those in bark. Ethanolic extracts exhibited good antioxidant activities with IC50 = 26 µg mL(-1) for DPPH and EC50 = 50 µg mL(-1) for FRAP. Identification by HPLC-DAD revealed the presence of nine phenolic compounds known for their high antioxidant activity. The results suggested that this species can be used as source of natural antioxidants.

Intervessel connectivity and relationship with patterns of lateral water exchange within and between xylem sectors in seven xeric shrubs from the great Sahara desert.

The main objective of this study was to evaluate the role of intervessel contacts in determining the patterns of hydraulic integration both within and between xylem sectors. The degree of intervessel contacts and the lateral exchange capability within and between sectors were examined and correlated in different xeric shrubs. A dye injection method was used to detect the connections between vessels; an apoplastic dye was sucked through a known number of vessels and its distribution in the xylem network was followed. Hydraulic techniques were used to measure axial and tangential conductivity both within and between xylem sectors. The intra- and inter-sector integration indexes were then determined as the ratio of tangential to axial conductance. Species differed significantly in the degree of intervessel contacts, intra- and inter-sector integration index. In all cases, hydraulic integration was observed to be higher within sector than between sectors. From the correlation analyses, the intervessel contacts showed a very weak relationship with inter-sector integration index and a strong positive relationship with intra-sector integration index. Results suggested that (1) the factors affecting patterns of lateral flow within xylem sectors might be relatively different from those between sectors. (2) The degree of intervessel contacts was a major determinant of hydraulic integration within the same xylem sector. (3) Intervessel connectivity alone was a poor predictor of hydraulic integration between different sectors, implying a significant contribution of other anatomical, physiological and environmental factors in determining the patterns of integrated-sectored transport within woody stems.