Health Risks Associated with Consumption of Vegetables Grown using Domestic Wastewater in Minna, Niger State, Nigeria

Most vegetables consumed in the cities of developing countries are grown using wastewater discharged through township drainage network. This paper, therefore, investigates the risk involved in the consumption of such vegetables. The human daily intake rate (DIR) and Health Risk Index (HRI) of heavy metals were calculated using established formulae and the values of DIR ranged from 0.10 mg/kg/day to 0.71 mg/kg/day in wastewater plots in dry season for adults and 0.10 mg/kg/day to 0.14 mg/kg/day for children. Health risk index (HRI) values ranges from 0.40 mg/kg/day to 0.75 mg/kg/day in wastewater plots for adults in dry season and 0.20 mg/kg/day to 0.95 mg/kg/day for children. In wet season wastewater plots, the HRI ranges from 0.40 mg/kg/day to 0.95 mg/kg/day for children. The values of Hazard index (HI) ranged between 1.00 mg/kg/day and 1.21 mg/kg/day for all the seasons. Statistical analysis showed that there is a significant difference between the wet and dry season values for all the parameters assessed. Finally, uptake of heavy metals from the soil by all the vegetable crops under investigation was established. Therefore proper monitoring needs to be carried out to regulate consumption of vegetables produced from the experimental sites as continuous application of the industrial wastewater may lead to further accumulation of these heavy metals

Assessment of Heavy Metals Uptake by Vegetables Cultivated on Soil Receiving Industrial Wastewater in Minna, Nigeria

Consumption of vegetable crops grown on soil irrigated with industrial wastewater has been the order of the day in most urban towns and cities of Nigeria, despite reports of its serious health impact. This study assessed the possibility of uptake of heavy metals by crops grown on soil receiving industrial wastewater during rainy and dry seasons. The crops investigated are Spinach, Cayenne Pepper, Jute mallow, roselle and lady’s fingers okra. The initial composition of the wastewater was analyzed to contain 0.89 mg/l of chromium, 0.74 mg/l of cadmium, 1.04 mg/l of copper and 2.81 mg/l of iron. Control water used for this experiment contain no trace of any of these heavy metals. The experimental soil was also analyzed and contained 0.10 mg/kg of chromium, 0.06 mg/kg of iron before irrigation in dry season. After irrigation at the wastewater plots, the heavy metal concentrations in soil had increased to 6.24 mg/kg of chromium and 7.50 mg/kg of iron. In wet season, the concentrations of heavy metals in the soil were 0.00 mg/kg of chromium and 2.32 mg/kg of iron before irrigation. After irrigation in wet season, the concentrations increased to 6.01 mg/kg of iron. Mean difference of heavy metal concentrations were significantly high in vegetables in dry season, with values ranging from 0.03 mg/kg to 211mg/kg in wastewater plots, 0.20 mg/kg to 215 mg/kg in wet seasons wastewater plots, 0.00 mg/kg to 157 mg/kg in dry season. It is however recommended that consumption of vegetables irrigated with domestic/industrial wastewater be strongly discouraged because of its serious health implications.&nbsp

A protosolar nebula origin for the ices agglomerated by Comet 67P/Churyumov-Gerasimenko

The nature of the icy material accreted by comets during their formation in the outer regions of the protosolar nebula is a major open question in planetary science. Some scenarios of comet formation predict that these bodies agglomerated from crystalline ices condensed in the protosolar nebula. Concurrently, alternative scenarios suggest that comets accreted amorphous ice originating from the interstellar cloud or from the very distant regions of the protosolar nebula. On the basis of existing laboratory and modeling data, we find that the N$_2$/CO and Ar/CO ratios measured in the coma of the Jupiter family comet 67P/Churyumov-Gerasimenko by the ROSINA instrument aboard the European Space Agency's Rosetta spacecraft match those predicted for gases trapped in clathrates. If these measurements are representative of the bulk N$_2$/CO and Ar/CO ratios in 67P/Churyumov-Gerasimenko, it implies that the ices accreted by the comet formed in the nebula and do not originate from the interstellar medium, supporting the idea that the building blocks of outer solar system bodies have been formed from clathrates and possibly from pure crystalline ices. Moreover, because 67P/Churyumov-Gerasimenko is impoverished in Ar and N$_2$, the volatile enrichments observed in Jupiter's atmosphere cannot be explained solely via the accretion of building blocks with similar compositions and require an additional delivery source. A potential source may be the accretion of gas from the nebula that has been progressively enriched in heavy elements due to photoevaporation.Comment: The Astrophysical Journal Letters, in pres

Characterization of the Subsurface of 67P/Churyumov-Gerasimenko's Abydos Site

We investigate the structure of the subsurface of the Abydos site using a cometary nucleus model with parameters adapted to comet 67P/Churyumov-Gerasimenko and the Abydos landing site. We aim to compare the production rates derived from our model with those of the main molecules measured by Ptolemy. This will allow us to retrieve the depths at which the different molecules still exist in solid form

Observation of Anomalous Internal Pair Creation in 8^8Be: A Possible Signature of a Light, Neutral Boson

Electron-positron angular correlations were measured for the isovector magnetic dipole 17.6 MeV state ($J^\pi=1^+$, $T=1$) $\rightarrow$ ground state ($J^\pi=0^+$, $T=0$) and the isoscalar magnetic dipole 18.15 MeV ($J^\pi=1^+$, $T=0$) state $\rightarrow$ ground state transitions in $^{8}$Be. Significant deviation from the internal pair creation was observed at large angles in the angular correlation for the isoscalar transition with a confidence level of $> 5\sigma$. This observation might indicate that, in an intermediate step, a neutral isoscalar particle with a mass of 16.70$\pm0.35$ (stat)$\pm 0.5$ (sys) MeV$/c^2$ and $J^\pi = 1^+$ was created.Comment: 5 pages, 5 figure

Origin of molecular oxygen in Comet 67P/Churyumov-Gerasimenko

Molecular oxygen has been detected in the coma of comet 67P/Churyumov-Gerasimenko with abundances in the 1-10% range by the ROSINA-DFMS instrument on board the Rosetta spacecraft. Here we find that the radiolysis of icy grains in low-density environments such as the presolar cloud may induce the production of large amounts of molecular oxygen. We also show that molecular oxygen can be efficiently trapped in clathrates formed in the protosolar nebula, and that its incorporation as crystalline ice is highly implausible because this would imply much larger abundances of Ar and N2 than those observed in the coma. Assuming that radiolysis has been the only O2 production mechanism at work, we conclude that the formation of comet 67P/Churyumov-Gerasimenko is possible in a dense and early protosolar nebula in the framework of two extreme scenarios: (1) agglomeration from pristine amorphous icy grains/particles formed in ISM and (2) agglomeration from clathrates that formed during the disk's cooling. The former scenario is found consistent with the strong correlation between O2 and H2O observed in 67P/C-G's coma while the latter scenario requires that clathrates formed from ISM icy grains that crystallized when entering the protosolar nebula.Comment: The Astrophysical Journal Letters, in pres

The Distribution of Constituent Charm Quarks in the Hadron

Using a statistical approach in the framework of non-covariant perturbation theory the distributions for light and charmed quarks in the hadron have been derived, taking into account the mass of the charmed quark. The parameters of the model have been extracted from the comparison with NA3 data on hadroproduction of J/psi particles. A reanalysis of the EMC data on charm production in muon-nucleon scattering has been performed. It has been found in comparison with the conventional source of charmed quarks from photon-gluon fusion, that the EMC data indicate the presence of an additional contribution from deep-inelastic scattering on charmed quarks at large x. The resulting admixture of the Fock states, containing charmed quarks in the decomposition of the proton wave function is of the order of 1%. The approach presented for the excitation of the Fock states with charmed quarks can also be applied to states with beauty quarks as well as to the hadronic component of the virtual photon (resolved photon component).Comment: 23 pages, 4 PostScript figures, Latex2e. In revised version in comparison with the original one all (?) mistypings have been corrected, one more thank has been added and the comparison of the pion and the proton J/psi production is described in more detai

Burden of cytopaenias among HIV positive pregnant women at the University College Hospital, Ibadan

Introduction: Few studies have examined cytopaenia among HIV positive pregnant women.Objectives: To assess burden of cytopaenia among HIV positive pregnant women.Methodology: This cross-sectional study of women on HAART <6months, defined anemia as hematocrit <33%, leucopenia as total white blood cell count <3,000 cells/mm3 and thrombocytopenia as absolute platelet count <100,000 cells/mm3. Univariate and bivariate analyses were performed.Results: Over 8 years, of 1,197 women, the mean age was 29.02(±5.4) years and mean gestational age 25.9(±8.1) weeks. Prevalence of anaemia was 76.8%, leucopaenia 6.9% and thrombocytopenia 4.7%. The mean haematocrit was 28.5%(±4.5); median white blood count 5,500/mm3 ; median platelet count 200,000/mm3 and median CD4 323 cells/mm3.Mean haematocrit was highest (29.7%±5.3) in women in the first trimester but lowest (28.4% ±4.6) in women in second trimester (p=0.04). Compared with earlier trimesters, women in the third trimester had higher median white blood count (5,600 cells/mm3), higher neutrophil (61.0% ±11.2) but lower lymphocytes(28.3%± 9.2) (p=0.18; 0.00, 0.00). Median absolute platelet count was highest (206,000 cells/mm3) in the first trimester but lowest (195,000 cells/mm3) in third trimester (0.04). Women with lower CD4 had higher prevalence of cytopaenias.Conclusion: Cytopaenias are not uncommon in this population especially with lower CD4

Hot Gauge Theories and ZNZ_{N} Phases

In this paper the several aspects of the $Z_{N}$ symmetry in gauge theories at high temperatures are discussed. The metastable $Z_{N}$ bubbles in the $SU(N)$ gauge theories with fermions may have, generically, unacceptable thermodynamic behavior. Their free energy $F \propto T^4$ with a positive proportionality constant. This leads not only to negative pressure but also to negative specific heat and, more seriously, to negative entropy. We argue that although such domains are important in the Euclidean theory, they cannot be interpreted as physical domains in Minkowski space. The related problem is connected with the analysis of the high-temperature limit of the confining phase. Using the two-dimensional QCD with adjoint fermions as a toy model we shall demonstrate that in the light fermion limit in this theory there is no breaking of the $Z_{N}$ symmetry in the high-temperature limit and thus there are no $Z_{N}$ bubbles.Comment: preprint PUPT-1415, 21

Dual variables for the SU(2) lattice gauge theory at finite temperature

We study the three-dimensional SU(2) lattice gauge theory at finite temperature using an observable which is dual to the Wilson line. This observable displays a behaviour which is the reverse of that seen for the Wilson line. It is non-zero in the confined phase and becomes zero in the deconfined phase. At large distances, it's correlation function falls off exponentially in the deconfined phase and remains non-zero in the confined phase. The dual variable is non-local and has a string attached to it which creates a Z(2) interface in the system. It's correlation function measures the string tension between oppositely oriented Z(2) domains. The construction of this variable can also be made in the four-dimensional theory where it measures the surface tension between oppositely oriented Z(2) domains.Comment: 13 pages, LaTeX, 4 figures are included in the latex fil