ABSTRACT

This study reviews the Public Transportation (PT) Systems and the opportunities and requirements applied

in Libya. Beginning with the definition of public transport systems and their functions and areas of applied and

advanced systems for public transport and advanced systems for traffic management, systems and operations of

transport vehicles and advanced systems to control private vehicle and safety, with a discussion of the

importance of each of them, this paper discusses the requirements of the application of Bus Rapid Transit

(BRT) systems in mass with focus placed on the importance of developing an outline plan for the public

transport systems. The concept master plan and the options available in Tripoli shall be discussed to develop its

map of structural public transportation systems and recommend consideration of the possible adoption of a map

structure developed in the advanced countries and some developing countries in this area, with their adaptations

depending on the circumstances of Tripoli. It also concludes with the need to establish a permanent institution

representing the parties involved, including the public sectors, academia; and vested in the institutions

responsible for managing, directing, and the preparation of a strategic plan for public transport systems,

including the development of the master plan for those systems. The study recommends starting with pilot

projects carefully selected by an explanatory expansion in the application.

Key words: public transport system, bus rapid transit, safety, control private vehicles, traffic management,

Tripoli.

ABSTRACT

This study reviews the Public Transportation (PT) Systems and the opportunities and requirements applied

in Libya. Beginning with the definition of public transport systems and their functions and areas of applied and

advanced systems for public transport and advanced systems for traffic management, systems and operations of

transport vehicles and advanced systems to control private vehicle and safety, with a discussion of the

importance of each of them, this paper discusses the requirements of the application of Bus Rapid Transit

(BRT) systems in mass with focus placed on the importance of developing an outline plan for the public

transport systems. The concept master plan and the options available in Tripoli shall be discussed to develop its

map of structural public transportation systems and recommend consideration of the possible adoption of a map

structure developed in the advanced countries and some developing countries in this area, with their adaptations

depending on the circumstances of Tripoli. It also concludes with the need to establish a permanent institution

representing the parties involved, including the public sectors, academia; and vested in the institutions

responsible for managing, directing, and the preparation of a strategic plan for public transport systems,

including the development of the master plan for those systems. The study recommends starting with pilot

projects carefully selected by an explanatory expansion in the application.

Key words: public transport system, bus rapid transit, safety, control private vehicles, traffic management,

Tripoli

Given the pressing need for new antiprotozoal drugs without cross-resistance with current (failing) chemotherapy, we have explored 3-tridecylpyridinium alkaloids (3TPAs), derivatives of viscosamine, as antiparasitic agents. We have developed a simple synthetic route toward viscosamine and related cyclic and linear monomers and oligomers. Evaluation for cytotoxicity on the protozoan parasites Trypanosoma brucei, Leishmania spp., and Plasmodium falciparum revealed several 3TPAs with antiprotozoal activity in the nanomolar range. Their promising selectivity index in vitro prompted us to study the dynamics of cytotoxicity on trypanosomes in more detail. Parasites were killed relatively slowly at therapeutically safe concentrations, in a process that did not target the cell cycle. Clearance of T. brucei cultures was observed at drug concentrations of 1–10 μM.

The higher strength 7xxx aluminum alloys exhibited low resistance to stress corrosion cracking (SCC) when aged to the peak hardness (T6 temper). The overaged alloys (T7 temper) developed to enhance the SCC with loss in the strength of the alloy. Recently, retrogression and re-aging (RRA) heat treatments are used for improving the SCC behavior for alloys in T6 tempers such as 7075, 7475 and 8090. In this study, an application of retrogression and re-aging heat treatment processes are carried out to enhance toughness properties of the 7079-T651 aluminum alloy, while maintaining the higher strength of T651-temper. The results of charpy impact energy and electrical conductivity tests show a significantly increases in absorbed energy and electrical conductivity values, when the alloys are exposed to various retrogression temperatures (190, 200, 210°C) and times (20, 40, 60 minutes), and then re-aged at 160°C for 18 hours.

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Abstract The contribution of supraspinal, spinal or peripheral mu-opioid receptors (MORs) to the overall antinociception of systemic centrally penetrating versus peripherally restricted opioids has not been thoroughly investi gated. Therefore, we examined paw pressure thresholds in Wistar rats with complete Freund’s adjuvant hindpaw inflammation following different doses of intraplantar (i.pl.) as well as intravenous (i.v.) fentanyl (6.25 50 mg/kg), morphine (1–7.5 mg/kg) or loperamide (1–7.5 mg/kg). Antago nism of the i.v. mu-opioid agonists by intracerebroventricular (i.c.v.), intrathecal (i.t.) or i.pl. naloxone-methiodide (NLXM) revealed the rela tive contributions of supraspinal, spinal and peripheral MOR to the overall antinociceptive effects. In parallel, the MOR density at these three levels of pain transmission was assessed by radioligand binding. Antinociceptive effects of i.v. fentanyl and morphine, but not of the peripherally restricted loperamide were two- to threefold greater and longer lasting compared with their i.pl. administration. I.c.v. but not i.pl. NLXM significantly antagonized fentanyl’s and morphine’s antinociception by 70–80%, whereas i.t. NLXM reduced it by 20–30%. In contrast, antinociception of i.v. loperamide was abolished by i.pl. but not by i.c.v. or i.t. NLXM. In parallel, a respective 32- and sixfold higher MOR density in supraspinal and spinal versus peripheral sensory neurons was detected. In conclusion, in comparison with supraspinal and spinal opioid receptors, peripheral opioid receptors do not significantly contribute to the antinociception of systemic fentanyl and morphine during inflammatory pain. Antinocicep tion of their i.v. administration was superior over both i.v and i.pl. lopera mide, acting exclusively via peripheral MOR. These findings may guide the future development of novel peripherally restricted opioids.

• Background and Aims: Loss in the antinociceptive efficacy of systemic, spinal, and supraspinal administration of opioids has been reported in rats with diabetic neuropathic pain. Recent studies investigated alterations in opioid receptor expression and signaling at the spinal level, however, results were conflicting. Since diabetic neuropathy is primarily a disease of the peripheral sensory neuron, this study aimed at investigating alterations of mu-opioid responsiveness during the development of streptozotocin-induced diabetic neuropathic pain in rats.

Background and Aims: The contribution of supraspinal, spinal or peripheral opioid receptors to the overall antinociceptive effects of centrally penetrating versus peripherally restricted opioids is still a matter of debate. Therefore, we examined the antinociceptive effects and its antagonism by intracerebroventricular, intrathecal or intraplantar naloxone methiodide of systemic fentanyl and morphine versus loperamide in relation to the density of mu-opioid receptors (MOR) at the three levels of pain transmission.

 Background and Aims: Painful diabetic neuropathy is a peripheral sensory neuron disease, is difficult to treat and is known to be less susceptible to opioid analgesics. In diabetic neuropathy little is known so far about alterations in mu-opioid receptor (MOR) expression, coupling and efficacy of sensory neurons within the spinal cord of diabetic neuropathy. Therefore, the aim of this study was to investigate the changes in MOR expression, signaling and function of sensory neurons at spinal cord level in streptozotocin induced diabetic rats. In addition, it is examined whether i.t. NGF treatment will restore the MOR expression and G-protein coupling and consequently will rescue the deficit in peripheral fentanyl induced analgesia of diabetic rats.

 Background and Aims: Visceral pain seems to be attenuated by intrathecal (i.t.) application of corticotropin-releasing factor (CRF) receptor antagonists. In contrast, i.t. CRF elicits inhibition of somatic pain that is reversed by the opioid antagonist naloxone. Previous studies have identified CRFR1 and more predominantly CRFR2 receptors within the dorsal horn of the spinal cord. At present it is unclear to which proportion each CRF receptor subtype contributes to the modulation of inflammatory somatic pain and on which opioid containing neuron population it is located.