RESUMO
Transverse single-spin asymmetries of very forward neutral pions generated in polarized p+p collisions allow us to understand the production mechanism in terms of perturbative and nonperturbative strong interactions. During 2017, the RHICf Collaboration installed an electromagnetic calorimeter in the zero-degree region of the STAR detector at the Relativistic Heavy Ion Collider (RHIC) and measured neutral pions produced at pseudorapidity larger than 6 in polarized p+p collisions at sqrt[s]=510 GeV. The large nonzero asymmetries increasing both in longitudinal momentum fraction x_{F} and transverse momentum p_{T} have been observed at low transverse momentum p_{T}<1 GeV/c for the first time, at this collision energy. The asymmetries show an approximate x_{F} scaling in the p_{T} region where nonperturbative processes are expected to dominate. A non-negligible contribution from soft processes may be necessary to explain the nonzero neutral pion asymmetries.
RESUMO
The past decade experienced a stunning change in the incidence and fatality rates of pesticide poisonings in China. A study on representative case records of pesticide poisoning in a chinese province is presented here. A three-fold increase in poisoning cases due to a lack of preventive measures was reported at the beginning of the 1980s, under the rural economic reformation. Occupational intoxication incidence was swiftly reduced within a couple of years, and further stepped down as the adequate means were taken. On the contrary, the increase in non-occupational cases declined very slowly. The fatality rate of occupational poisoning cases was kept low (around few per thousand), while the non-occupational remarkably declined from 30% to 11% thanks to the efforts of health and medical care centres. The number and fatality rate of non-occupational cases thus came to play a more and more important role. Such trend is worth our attention.
Assuntos
Doenças Profissionais/induzido quimicamente , Praguicidas/intoxicação , Doença Aguda , Adolescente , Adulto , China/epidemiologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Doenças Profissionais/epidemiologiaRESUMO
A retrospective cohort study on the effect of the suspected teratogenic pesticide N, N'-methylene-bis-(2-amino-1,3,4-thiadiazole) (MATDA) on outcomes of pregnancy was conducted. The exposed group (6,173 pregnancies) was composed of childbearing women who, during their gestation, consumed rice harvested from a field where MATDA had been applied. The control I group (10,145) came from an adjacent county where MATDA had never been used; the control II group (3,326) consisted of women who had been pregnant previous to the introduction of this pesticide in the same region as the exposed group. The validity of the survey was verified by comparability and data-checking studies. After adjustment for the calendar year, maternal age, and pregnancy order, no significant differences were found in rates of spontaneous abortion, fetal death and stillbirth, birth defects, as well as in sex ratio and birth weight between the study groups. The same result was found in the comparison of individual categories of malformation. The rates of the birth defects were 23.84, 21.49, and 22.78 per 1,000 live births for the exposed, internal, and external control groups, respectively. No dose-response relationship was revealed. The results were consistent with previous reports and indicated the difference between animal experiments and human exposures. Although MATDA is teratogenic in animals, it is clear that the pesticide does not adversely effect outcomes of pregnancy in humans as currently applied.