Preliminary survey of ticks (Acari : Ixodidae) on cattle in northern Sudan

In a cross sectional survey conducted during the period June 2001 to July 2002, the geographical distribution of ticks on cattle in the Sudan was determined. Seventeen locations were surveyed from Northern, Central, Eastern, Western, Blue Nile and White Nile Provinces. Total body collections of ticks were made from 20 cattle at each location. Four tick genera and 11 species were identified. The tick species collected included Amblyomma lepidum, Amblyomma variegatum, Boophilus decoloratus, Hyalomma anatolicum anatolicum, Hyalomma dromedarii, Hyalomma impeltatum, Hyalomma marginatum rufipes, Hyalomma truncatum, Rhipicephalus evertsi evertsi, Rhipicephalus sanguineus group and Rhipicephalus simus simus. Major ecological changes have occurred due to extensive animal movement, deforestation, desertification and establishment of large mechanized agricultural schemes. These factors have certainly affected the distribution of ticks and tick-borne diseases in the Sudan. The absence of A. variegatum and A. lepidum in northern Sudan was not surprising, since these tick species are known to survive in humid areas and not in the desert and semi-desert areas of northern Sudan. The absence of B. annulatus in northern and central Sudan is in accordance with the finding that this tick species is restricted to the southern parts of the central Sudan. The presence of H. anatolicum anatolicum in Um Benin in relatively high abundance is an interesting finding. The present finding may indicate that the southern limit of this species has changed and moved southwards to latitude 13o N. It is concluded that major changes in tick distribution have taken place in the Suda

Enhanced delivery and detection of terahertz frequency radiation from a quantum cascade laser within dilution refrigerator

We report on significant enhancements to the integration of terahertz (THz) quantum cascade lasers (QCL) and THz detection with a two-dimensional electron gas (2DEG) within a dilution refrigerator obtained by the inclusion of a multi-mesh 6 THz low-pass filter to block IR radiation, a Winston cone to focus light output, and gating the 2DEG for optimised sensitivity. We show that these improvements allow us to obtain a > 2.5 times reduced sample electron temperature (160 mK compared with 430 mK previously), during cyclotron resonance (CR) measurements of a 2DEG under QCL illumination. This opens up a route to performing sub-100 mK experiments using excitation by THz QCLs

Traffic Optimization and Multi-sided Pricing in Congested Networks

The paper we consider traffic optimization problem for a model with multi-sided dynamic pricing in the telecommunications market with incomplete competition and taking into account congested networks. The model consists in the use of mathematical modeling methods, game theory and queueing theory. It is assumed that telecommunication companies agree on the rules of incoming and outgoing traffic charging in pairs, and this charging is built as a function of the tariffs that companies offer their subscribers for service. Companies are limited the agreement on mutual rules of reciprocal proportional charging for access traffic at first, which subsequently determine the tariffs for the network users. The reciprocity of the rules means that companies are subject to the same rules for the entire time interval during which the agreement is in force. Taking into account imperfect competition in the telecommunications market and using traffic and profit optimization method for each company the equilibrium tariffs and the volume of services are found with subject to congestion in multi-service networks. Numerical calculation is performed to illustrate the results. © 2018, Springer Nature Switzerland AG

Traffic Optimization and Multi-sided Pricing in Congested Networks

The paper we consider traffic optimization problem for a model with multi-sided dynamic pricing in the telecommunications market with incomplete competition and taking into account congested networks. The model consists in the use of mathematical modeling methods, game theory and queueing theory. It is assumed that telecommunication companies agree on the rules of incoming and outgoing traffic charging in pairs, and this charging is built as a function of the tariffs that companies offer their subscribers for service. Companies are limited the agreement on mutual rules of reciprocal proportional charging for access traffic at first, which subsequently determine the tariffs for the network users. The reciprocity of the rules means that companies are subject to the same rules for the entire time interval during which the agreement is in force. Taking into account imperfect competition in the telecommunications market and using traffic and profit optimization method for each company the equilibrium tariffs and the volume of services are found with subject to congestion in multi-service networks. Numerical calculation is performed to illustrate the results. © 2018, Springer Nature Switzerland AG

The spreading of East Coast Fever into Great Bahr- El Ghazal Region, North West of South Sudan

Theileriosis is a fatal tick-borne disease caused by Theileria parva (T.parva) and affecting cattle mainly in East and Central Africa. A cross-sectional survey was conducted during June to November 2015 in 12 localities of Great Bahr- El Ghazal Region, South Sudan to investigate the prevalence of East Coast Fever in indigenous zebu (Nilotic) cattle kept under traditional management system. A total of 600 blood and 105 lymph node smears were collected from cattle. Microscopic examination of Giemsa stained blood smears revealed prevalence of 8.7% for Theileria spp piroplasms. Surprisingly, all the105 lymph node smears were negative for Theileria schizonts. In addition, out of 599 blood samples examined, 464 (77.5%) were positive for Theileria parva DNA using p104 nested polymerase chain reaction (nPCR) with significant differences (P < 0.001) between the localities of the study areas. Out of eight pooled ticks species that were identified (Amblyomma variegatum, Rhipicephalus evertsi evertsi, R. decoloratus, Hyalomma rufipes, R.annulatus, H. truncatum, R. sanguineus group and R. praetextus), one tick species (Amblyomma variegatum) was positive for Theileria parva DNA. The study concluded that T. parva is endemic in the region in spite of the absence of R. appendiculatus. Detection of T. parva DNA in A. variegatum may indicate the role of this tick species in transmission of T. parva among cattle. However, a need for further investigationemploying more samples and using more advanced techniques is highly recommended. Keywords: Epidemiology, East Coast fever; Bahr- El Ghazal; South Sudan

Molecular characterization of Theileria parva parasites from South Sudan using the PCR-RFLP approach on antigen genes

In an attempt to characterize Theileria parva parasites circulating in South Sudan cattle , polymerase chain reaction (PCR)-based assays were carried out using four single copy encoding antigen genes p104, PIM, p150 and p67 in addition to one microsatellite MS321. A total of 20 bovine DNA samples from two locations in South Sudan were included in this study, in addition to two references strains, Muguga and Katete. A total of nine alleles were identified for the polymorphic immunodominant molecule (PIM) locus using restriction fragment length polymorphism (RFLP), against 2 alleles each for the p150 and p104 loci, respectively. This confirms that differences in the polymorphic PIM genes alone could be used to characterize subdivisions in the T. parva populations in the field. On the other hand, 4 alleles were identified for the MS321 locus and 2 alleles for the p67 locus. The data indicate that the studied parasites are genetically closely related, mainly cattle derived and genetically quite distinct from the Muguga strain

Preliminary survey of ticks (Acari: Ixodidae) on cattle in Central Equatoria State, Southern Sudan

In a preliminary survey conducted in 2005, the species composition and seasonality of ticks infesting cattle in Central Equatoria State, Southern Sudan was determined. Three locations were selected (Gumbo, Khor Rumla and Nyaing) and surveyed every 3 months. Two cattle herds in each of the three locations were visited four times during the study period. Total body collections of ticks were made from each of five cattle (Nilotic Zebu breed) kept in six different herds. Four tick genera and ten species were identified. The tick species identified were Amblyomma lepidum, Amblyomma variegatum, Boophilus annulatus, Boophilus decoloratus, Hyalomma marginatum rufipes, Hyalomma truncatum, Rhipicephalus appendiculatus, Rhipicephalus evertsi evertsi, Rhipicephalus praetextatus and Rhipicephalus sanguineus group. The highest number of ticks was collected in October during the rainy season. A finding of great significance was that R. appendiculatus, vector of East Coast fever, has now firmly established itself throughout the year with possible implications for cattle production in Central Equatoria State

شناسایی مولکولی انگل تیلریا پاروا در جنوب سودان با استفاده از آزمون PCR-RFLP بر روی ژن های مولد آنتی ژن

In an attempt to characterize Theileria parva parasites circulating in South Sudan cattle , polymerase chain reaction (PCR)-based assays were carried out using four single copy encoding antigen genes p104, PIM, p150 and p67 in addition to one microsatellite MS321. A total of 20 bovine DNA samples from two locations in South Sudan were included in this study, in addition to two references strains, Muguga and Katete. A total of nine alleles were identified for the polymorphic immunodominant molecule (PIM) locus using restriction fragment length polymorphism (RFLP), against 2 alleles each for the p150 and p104 loci, respectively. This confirms that differences in the polymorphic PIM genes alone could be used to characterize subdivisions in the T. parva populations in the field. On the other hand, 4 alleles were identified for the MS321 locus and 2 alleles for the p67 locus. The data indicate that the studied parasites are genetically closely related, mainly cattle derived and genetically quite distinct from the Muguga strain

Akt2, a Novel Functional Link between p38 Mitogen-Activated Protein Kinase and Phosphatidylinositol 3-Kinase Pathways in Myogenesis

Activation of either the phosphatidylinositol 3-kinase (PI 3-kinase)/Akt or the p38 mitogen-activated protein kinase (MAPK) signaling pathways accelerates myogenesis but only when the reciprocal pathway is functional. We therefore examined the hypothesis that cross-activation between these signaling cascades occurs to orchestrate myogenesis. We reveal a novel and reciprocal cross-talk and activation between the PI 3-kinase/Akt and p38 MAPK pathways that is essential for efficient myoblast differentiation. During myoblast differentiation, Akt kinase activity correlated with S473 but not T308 phosphorylation and occurred 24 h after p38 activation. Inhibition or activation of p38 with SB203580, dominant-negative p38, or MKK6EE regulated Akt kinase activity. Analysis of Akt isoforms revealed a specific increase in Akt2 protein levels that coincided with AktS473 phosphorylation during myogenesis and an enrichment of S473-phosphorylated Akt2. Akt2 promoter activity and protein levels were regulated by p38 activation, thus providing a mechanism for communication. Subsequent Akt activation by S473 phosphorylation was PI 3-kinase dependent and specific for Akt2 rather than Akt1. Complementary to p38-mediated transactivation of Akt, activation or inhibition of PI 3-kinase regulated p38 activity upstream of MKK6, demonstrating reciprocal communication and positive feedback characteristic of myogenic regulation. Our findings have identified novel communication between p38 MAPK and PI 3-kinase/Akt via Akt2