International Comparison of the Sources of Productivity Slowdown 1973 1982

This paper uses an integrated model of aggregate supply to analyze the post-1973 slowdown in productivity growth in the seven major OECD economies. Factor substitution, unexpected demand changes, profitability, and inventory disequilibrium all contribute to the explanation, which is based on a three-factor nested aggregate production function, including energy, and postulating Harrod-neutral disembodied technical progress. The model is first applied separately to the seven countries assuming constant (though country-specific) rates of technical progress. This model provides empirical evidence that this rate of progress has in fact slowed down for several of the faster-growing countries, even after adjusting for factor substitution and cyclical factors. The model is therefore re-estimated, and the sources of productivity decline recalculated, on the hypothesis that rates of efficiency growth in other countries are converging to those in the United States.

Faecal carriage of multi-drug resistant Enterobacteriaceae in hospitalized children at University Teaching Hospital Sylvanus Olympio of Lomé, Togo

Background: High prevalence of infections and associated antibiotherapy may put children at increased risk for development of multidrug-resistance (MDR), mostly to bacterial infections. The objective of this study therefore was to determine the prevalence of gastrointestinal carriage of MDR Enterobacteriaceae among hospitalized children in the Paediatric department of Sylvanus Olympio University Hospital, Lomé, Togo.Methodology: A descriptive cross-sectional study was carried out on randomly selected hospitalized children in the Paediatric wards of the hospital from November 03 to November 10, 2020, after obtaining informed consent from their parents/guardians. Rectal swabs and stool samples were collected from each participant and cultured for isolation of members of the family Enterobacteriaceae on Hektoen enteric agar containing 4 µg/L cefotaxime, which was incubated aerobically at 37oC for 24 hours. The isolates were identified using in-house biochemical tests. Antibiotic susceptibility test (AST) of each isolate to a panel of antibiotics including ertapenem and imipenem was done by the disc diffusion method and interpreted according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) clinical breakpoints version 2020 V.1.1. ESBL production was detected by the double-disc synergy test of amoxicillin and clavulanic acid, and resistance to carbapenem was inferred by resistance to ertapenem and imipenem discs in the AST. Multi-drug resistance (MDR) was defined as resistance to at least three families of antibiotics. Statistical analysis of data was carried out on Excel 2010 and EPI INFO 7.2 and p value < 0.05 was considered to be statistical significance. Results: A total of 70 hospitalized children during the study period were randomly recruited with an average age of 4 years 3 days and a range of 1 day to 18 years. The male gender was predominant (54.3%) with a M: F ratio of 1.2. Samples were culture positive in 85.7% (60/70) and a total of 72 species of Enterobacteriaceae were isolated in 93.3% (56/60) of these cultures. Escherichia coli was the most frequently isolated species(56.9%, 41/72). More than 90% (65/72) of the isolates were resistant to ampicillin, 58.3% (42/72) to third generation cephalosporins, 59.7% (43/72) to fourth generation cephalosporins, 43% (31/72) to aminoglycosides, 55.6% (40/72) were multi-drug resistant, 48.6% (35/72) were ESBL-producing strains, and 6.9% (5/72) were carbapenem resistant. Eighty-three percent (29/35) of ESBL-producing and all the carbapenem resistant isolates (5/5) were recovered from children on antibiotic therapy. The prevalence of ESBL-producing phenotypes among culture-positive children on antibiotic treatment (72.5%, 29/40) was significantly higher than among culture-positive children not on antibiotic treatment (20.0%, 4/20), indicating that antibiotic therapy was significantly associated with carriage of MDR isolates (OR=10.545, 95% CI=2.882-38.590, p=0.0002). Conclusion: The high faecal carriage rate of MDR Enterobacteriaceae, which are all ESBL-producing strains, in this study is worrying. There is urgent need to develop measures to monitor and limit the spread of these MDR organisms in children and the community in Togo

High faecal carriage of extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-PE) among hospitalized patients at Sylvanus Olympio Teaching Hospital, Lomé, Togo in 2019

Background: Extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-PE) are a global health concern, associated with increased morbidity and mortality. Even in the absence of infections, colonization by these pathogens is still a great threat because of the risk of cross transfer among hospitalized patients. Faecal carriage of ESBL-PE remained poorly documented in Africa. This study aimed to determine faecal carriage rate of ESBL-PE, factors associated with carriage, and antimicrobial susceptibility of the strains among hospitalized patients at Sylvanus Olympio Teaching Hospitals (CHU SO) in Lomé, Togo. Methodology: This was a cross-sectional study of 105 randomly selected hospitalized patients between September and November 2019. Socio-demographic and clinical data as well as rectal swabs were collected after obtaining the consent of the selected participants. Rectal swabs were cultured on selective bromocresol purple (BCP) lactose agar containing 6µg/l ceftazidime, for isolation of Enterobacteriaceae. Identification of each isolate was performed using Uriselect 4 medium and API 20E. Antibiotic susceptibility of the bacterial isolates was performed by the Bauer-Kirby agar disc diffusion test and interpreted according to CASFM-EUCAST recommendations. Results: The faecal carriage rate of ESBL-PE among selected hospitalized patients was 80.9% (85/105). Escherichia coli was the most frequent bacteria 69.5% (73/105), followed by Klebsiella pneumoniae 22.8% (24/105). The antibiotic profile of ESBL producing Escherichia coli showed resistance to amoxycillin+clavulanic acid (72.6%), ticarcillin+clavulanic acid (82.2%), piperacillin+tazobactam (30.1%), cefoxitin (30.1%) ciprofloxacin (84.9%), levofloxacin (76.7%), nalidixic acid (83.6%), chloramphenicol (26.0%), gentamicin (49.3%), sulfamethoxazole-trimethoprim (86.3%), imipenem (5.5%), and ertapenem (21.9%). All (100%) isolates were sensitive to amikacin and fosfomycin. None of the characteristics or risk factors assessed was significantly associated with faecal carriage of ESBL-PE. Conclusion: Faecal carriage rate of ESBL-PE in these hospitalized patients was very high, but no factor was associated with carriage of ESBL-PE among the study population. Implementation of infection control measures, and surveillance are needed to limit the spread of these resistant pathogens within CHU SO healthcare facilities

Baited-boats : an innovative way to control riverine tsetse, vectors of sleeping sickness in West Africa

Background: Human African Trypanosomiasis (HAT) is an important neglected tropical disease caused by Trypanosoma spp. parasites transmitted by species of tsetse fly (Glossina spp). The most important vectors of HAT are riverine tsetse and these can be controlled by attracting them to stationary baits such as insecticide-impregnated traps or targets deployed along the banks of rivers. However, the geographical nature of some riverine habitats, particularly mangroves but also extensive lake and river networks, makes deployment of baits difficult and limits their efficacy. It is known that tsetse are attracted by the movement of their hosts. Our hypothesis was that mounting a target on canoes typically used in Africa ('pirogues') would produce an effective means of attracting-and-killing riverine tsetse in extensive wetland habitats. Methods: In Folonzo, southern Burkina Faso, studies were made of the numbers of tsetse attracted to a target (75 x 50 cm) of blue cloth and netting mounted on a pirogue moving along a river, versus the same target placed on the riverbank. The targets were covered with a sticky film which caught tsetse as they contacted the target. Results: The pirogue-mounted target caught twice as many G. tachinoides and G. p. gambiensis, and 8 times more G. morsitans submorsitans than the stationary one (P < 0.001). Conclusion: Pirogues are common vehicle for navigating the rivers, lakes and swamps of West Africa. The demonstration that tsetse can be attracted to targets mounted on such boats suggests that pirogues might provide a cost-effective and convenient platform for deploying targets to control tsetse in the mangrove systems of West Africa where HAT persists. Further studies to assess the impact of pirogue-mounted targets on tsetse populations in HAT foci and the protective value of targets for pirogue passengers are recommended

Detection and identification of pathogenic trypanosome species in tsetse flies along the Comoe River in Cote d'Ivoire

In order to identify pathogenic trypanosomes responsible for African trypanosomiasis, and to better understand tsetse-trypanosome relationships, surveys were undertaken in three sites located in different eco-climatic areas in Cote d'Ivoire during the dry and rainy seasons. Tsetse flies were caught during five consecutive days using biconical traps, dissected and microscopically examined looking for trypanosome infection. Samples from infected flies were tested by PCR using specific primers for Trypanosoma brucei s.l., T. congolense savannah type, T. congolense forest type and T. vivax. Of 1941 tsetse flies caught including four species, i.e. Glossina palpalis palpalis, G. p. gambiensis, G. tachinoides and G. medicorum, 513 (26%) were dissected and 60 (12%) were found positive by microscopy. Up to 41% of the infections were due to T. congolense savannah type, 30% to T. vivax, 20% to T. congolense forest type and 9% due to T. brucei s.l. All four trypanosome species and subgroups were identified from G. tachinoides and G. p. palpalis, while only two were isolated from G. p. gambiensis (T. brucei s.l., T. congolense savannah type) and G. medicorum (T. congolense forest, savannah types). Mixed infections were found in 25% of cases and all involved T. congolense savannah type with another trypanosome species. The simultaneous occurrence of T. brucei s.l., and tsetse from the palpalis group may suggest that human trypanosomiasis can still be a constraint in these localities, while high rates of T. congolense and T. vivax in the area suggest a potential risk of animal trypanosomiasis in livestock along the Comoe River

Multifragmentation of a very heavy nuclear system (II): bulk properties and spinodal decomposition

The properties of fragments and light charged particles emitted in multifragmentation of single sources formed in central 36AMeV Gd+U collisions are reviewed. Most of the products are isotropically distributed in the reaction c.m. Fragment kinetic energies reveal the onset of radial collective energy. A bulk effect is experimentally evidenced from the similarity of the charge distribution with that from the lighter 32AMeV Xe+Sn system. Spinodal decomposition of finite nuclear matter exhibits the same property in simulated central collisions for the two systems, and appears therefore as a possible mechanism at the origin of multifragmentation in this incident energy domain.Comment: 28 pages including 14 figures; submitted to Nucl. Phys.

Neemazal ® as a possible alternative control tool for malaria and African trypanosomiasis?

Background: Research efforts to identify possible alternative control tools for malaria and African trypanosomiasis are needed. One promising approach relies on the use of traditional plant remedies with insecticidal activities. Methods: In this study, we assessed the effect of blood treated with different doses of NeemAzal ® (NA, neem seed extract) on mosquitoes (Anopheles coluzzii) and tsetse flies (Glossina palpalis gambiensis) (i) avidity to feed on the treated blood, (ii) longevity, and (iii) behavioural responses to human and calf odours in dual-choice tests. We also gauged NeemAzal ® toxicity in mice. Results: In An. coluzzii, the ingestion of NA in bloodmeals offered by membrane feeding resulted in (i) primary antifeedancy; (ii) decreased longevity; and (iii) reduced response to host odours. In G. palpalis gambiensis, NA caused (i) a knock-down effect; (ii) decreased or increased longevity depending on the dose; and (iii) reduced response to host stimuli. In both cases, NA did not affect the anthropophilic rate of activated insects. Overall, the most significant effects were observed with NA treated bloodmeals at a dose of 2000 μg/ml for mosquitoes and 50 μg/ml for tsetse flies. Although no mortality in mice was observed after 14 days of follow-up at oral doses of 3.8, 5.6, 8.4 and 12.7 g/kg, behavioural alterations were noticed at doses above 8 g/kg. Conclusion: This study revealed promising activity of NA on A. coluzzii and G. palpalis gambiensis but additional research is needed to assess field efficacy of neem products to be possibly integrated in vector control programmes

Measurements of sideward flow around the balance energy

Sideward flow values have been determined with the INDRA multidetector for Ar+Ni, Ni+Ni and Xe+Sn systems studied at GANIL in the 30 to 100 A.MeV incident energy range. The balance energies found for Ar+Ni and Ni+Ni systems are in agreement with previous experimental results and theoretical calculations. Negative sideward flow values have been measured. The possible origins of such negative values are discussed. They could result from a more important contribution of evaporated particles with respect to the contribution of promptly emitted particles at mid-rapidity. But effects induced by the methods used to reconstruct the reaction plane cannot be totally excluded. Complete tests of these methods are presented and the origins of the ``auto-correlation'' effect have been traced back. For heavy fragments, the observed negative flow values seem to be mainly due to the reaction plane reconstruction methods. For light charged particles, these negative values could result from the dynamics of the collisions and from the reaction plane reconstruction methods as well. These effects have to be taken into account when comparisons with theoretical calculations are done.Comment: 27 pages, 15 figure

Multifragmentation in Xe(50A MeV)+Sn Confrontation of theory and data

We compare in detail central collisions Xe(50A MeV) + Sn, recently measured by the INDRA collaboration, with the Quantum Molecular Dynamics (QMD) model in order to identify the reaction mechanism which leads to multifragmentation. We find that QMD describes the data quite well, in the projectile/target region as well as in the midrapidity zone where also statistical models can be and have been employed. The agreement between QMD and data allows to use this dynamical model to investigate the reaction in detail. We arrive at the following observations: a) the in medium nucleon nucleon cross section is not significantly different from the free cross section, b) even the most central collisions have a binary character, c) most of the fragments are produced in the central collisions and d) the simulations as well as the data show a strong attractive in-plane flow resembling deep inelastic collisions e) at midrapidity the results from QMD and those from statistical model calculations agree for almost all observables with the exception of ${d^2 \sigma \over dZdE}$. This renders it difficult to extract the reaction mechanism from midrapidity fragments only. According to the simulations the reaction shows a very early formation of fragments, even in central collisions, which pass through the reaction zone without being destroyed. The final transverse momentum of the fragments is very close to the initial one and due to the Fermi motion. A heating up of the systems is not observed and hence a thermal origin of the spectra cannot be confirmed.Comment: figures 1 and 2 changed (no more ps -errors