SPORT: A new sub-nanosecond time-resolved instrument to study swift heavy ion-beam induced luminescence - Application to luminescence degradation of a fast plastic scintillator

We developed a new sub-nanosecond time-resolved instrument to study the dynamics of UV-visible luminescence under high stopping power heavy ion irradiation. We applied our instrument, called SPORT, on a fast plastic scintillator (BC-400) irradiated with 27-MeV Ar ions having high mean electronic stopping power of 2.6 MeV/\mu m. As a consequence of increasing permanent radiation damages with increasing ion fluence, our investigations reveal a degradation of scintillation intensity together with, thanks to the time-resolved measurement, a decrease in the decay constant of the scintillator. This combination indicates that luminescence degradation processes by both dynamic and static quenching, the latter mechanism being predominant. Under such high density excitation, the scintillation deterioration of BC-400 is significantly enhanced compared to that observed in previous investigations, mainly performed using light ions. The observed non-linear behaviour implies that the dose at which luminescence starts deteriorating is not independent on particles' stopping power, thus illustrating that the radiation hardness of plastic scintillators can be strongly weakened under high excitation density in heavy ion environments.Comment: 5 figures, accepted in Nucl. Instrum. Methods

Exact results on spin dynamics and multiple quantum dynamics in alternating spin-1/2 chains with XY-Hamiltonian at high temperatures

We extend the picture of a transfer of nuclear spin-1/2 polarization along a homogeneous one-dimensional chain with the XY-Hamiltonian to the inhomogeneous chain with alternating nearest neighbour couplings and alternating Larmor frequencies. To this end, we calculate exactly the spectrum of the spin-1/2 XY-Hamiltonian of the alternating chain with an odd number of sites. The exact spectrum of the XY-Hamiltonian is also applied to study the multiple quantum (MQ) NMR dynamics of the alternating spin-1/2 chain. MQ NMR spectra are shown to have the MQ coherences of zero and $\pm$ second orders just as in the case of a homogeneous chain. The intensities of the MQ coherences are calculated.Comment: 10 pages, 4 figure

Evaluation of two lyophilized molecular assays to rapidly detect foot-and-mouth disease virus directly from clinical samples in field settings

Accurate, timely diagnosis is essential for the control, monitoring and eradication of foot‐and‐mouth disease (FMD). Clinical samples from suspect cases are normally tested at reference laboratories. However, transport of samples to these centralized facilities can be a lengthy process that can impose delays on critical decision making. These concerns have motivated work to evaluate simple‐to‐use technologies, including molecular‐based diagnostic platforms, that can be deployed closer to suspect cases of FMD. In this context, FMD virus (FMDV)‐specific reverse transcription loop‐mediated isothermal amplification (RT‐LAMP) and real‐time RT‐PCR (rRT‐PCR) assays, compatible with simple sample preparation methods and in situ visualization, have been developed which share equivalent analytical sensitivity with laboratory‐based rRT‐PCR. However, the lack of robust ‘ready‐to‐use kits’ that utilize stabilized reagents limits the deployment of these tests into field settings. To address this gap, this study describes the performance of lyophilized rRT‐PCR and RT‐LAMP assays to detect FMDV. Both of these assays are compatible with the use of fluorescence to monitor amplification in real‐time, and for the RT‐LAMP assays end point detection could also be achieved using molecular lateral flow devices. Lyophilization of reagents did not adversely affect the performance of the assays. Importantly, when these assays were deployed into challenging laboratory and field settings within East Africa they proved to be reliable in their ability to detect FMDV in a range of clinical samples from acutely infected as well as convalescent cattle. These data support the use of highly sensitive molecular assays into field settings for simple and rapid detection of FMDV

Effect of place of birth and transport on morbidity and mortality of preterm newborns

OBJETIVO: Verificar a influência do local de nascimento e do transporte sobre a morbimortalidade de recém-nascidos prematuros na Região Sul do Brasil. MÉTODOS: Estudo de coorte com recém-nascidos prematuros transferidos para a unidade de tratamento intensivo de referência (grupo transporte = 61), tendo sido acompanhados até a alta. Os dados sobre o atendimento no hospital de origem e transporte foram obtidos no momento da internação. Esse grupo foi comparado com neonatos da maternidade de referência, pareados por idade gestacional (grupo controle = 123), tendo como desfecho primário o óbito e desfechos secundários as alterações da glicemia, temperatura e saturação de oxigênio no momento da internação e a incidência de enterocolite necrosante, displasia broncopulmonar e sepses. Na associação entre as variáveis e o desfecho, foi utilizado o risco relativo. Foi adotado um nível de significância de α = 5% e β = 90%. RESULTADOS: A distância média percorrida foi de 91 km. A idade gestacional média foi de 34 semanas. Entre os recém-nascidos transferidos, 23% (n = 14) não tiveram atendimento pediátrico na sala de parto. No transporte, 33% dos recém-nascidos foram acompanhados por pediatra, e os equipamentos utilizados foram: incubadora (57%), bomba de infusão (13%), oxímetro (49%) e aparelho para aferição da glicemia (21%). O grupo transporte apresentou maior incidência de hiperglicemia, risco relativo (RR) = 3,2 (2,3-4,4), hipoglicemia, RR = 2,4 (1,4-4,0), hipertermia, RR = 2,5 (1,6-3,9), e hipoxemia, RR = 2,2 (1,6-3,0). Foram observados 18% de óbitos no grupo dos transferidos e 8,9% no grupo controle, RR = 2,0 (1,0-2,6). CONCLUSÕES: A pesquisa expõe deficiências no atendimento e transporte dos recém-nascidos, sendo necessária uma melhor organização do atendimento perinatal e do transporte na região nordeste do Rio Grande do Sul.OBJECTIVE: To evaluate the effect of place of birth and transport on morbidity and mortality of preterm newborns in the southern region of Brazil. METHODS: This cohort study included preterm newborns transported to a reference intensive care unit (transport group = 61) and followed up until discharge. Data about care in hospital of origin and transport were obtained at admission. This group was compared with infants born in the maternity ward of the reference hospital paired according to gestational age (control group = 123). Primary outcome was death, and secondary outcomes were changes in blood glucose, temperature and oxygen saturation at admission and the incidence of necrotizing enterocolitis, bronchopulmonary dysplasia and sepsis. Relative risk (RR) was used to evaluate the association between variables and outcome. The level of significance was set at α = 5% and β = 90%. RESULTS: Mean travel distance was 91 km. Mean gestational age was 34 weeks. Of the neonates in the transport group, 23% (n = 14) did not receive pediatric care in the delivery room. During transportation, 33% of newborns were accompanied by a pediatrician, and the equipment available was: incubator (57%), infusion pump (13%), oximeter (49%) and device for blood glucose test (21%). The transport group had a greater incidence of hyperglycemia (RR = 3.2; 2.3-4.4), hypoglycemia (RR = 2.4; 1.4-4.0), hyperthermia (RR = 2.5; 1.6-3.9), and hypoxemia (RR = 2.2; 1.6-3.0). The percentage of deaths was 18% in the transport group and 8.9% in the control group (RR = 2.0; 1.0-2.6). CONCLUSIONS: This study revealed deficiencies in neonatal care and transport. Perinatal care and transport should be better organized in the northeastern region of Rio Grande do Sul, Brazil

Evaluation of the Efficiency of Aqueous Extact of Neem Fruits on Insect Pest of Rice in Rice Agroecosystem of Maga in the Far North Region of Cameroon

The chemical fight against insects pest causes many problems on the biodiversity of ecosystems, destabilizes the trophic level of the ecosystem and has harmful effects on the on health human. Mean while the biological fight using plants extractions can equally play the same role of killing pest, reason why the present study which was carried out in the irrigated perimeters of Maga in the Far North region of Cameroon, have as principal objective to evaluate the aqueous extraction of neem fruit on the insects pest of rice. The specific objectives were to know the biological diversity of insect pest in the irrigated perimeters of Maga, and their repartitioning in the phenological stages, again, to see the effects of the aqueous extractions of the neem fruits on the insects pest per variety and in function of the phenological stages, also to evaluate the damages cause by insects pest during the talling stage in function of the varieties, finally, to evaluate loss cause by the insects pest. The study was made on two rice varieties which were IR46 and NERICA3 in a split plot disposition. The capturing of the insects was done with the help of a sweep net and the identification of the species was done with the help of an entomological buttle, the identification key of insects by Heinrich (1993), Hill (1983), Heinrichs and Barrion (2004) and the families recognition keys by Delvare and Aberlenc (1989).The method of Breniere permited the estimation of loss of output at the talling and harvesting stages of rice caused by the insect pest. The analysis of variance of the result was done using SPSS 20. In the class of insects, twenty two species of insects fall in twenty families divided in seven orders were collected. Among the captured insects, we investigated fourteen insects which were pest. The biological fight have shown an effectiveness in the nursery, talling, and a positive and non negligible effects on the reduction insects pest in the heading and maturation stages and thus has permitted the reduction of damages from insects on the rice plants