Tree structural and species diversities in Okwangwo Forest, Cross River State, Nigeria

For sound forest management decisions, appraisal of flora species and forest structure is crucial for any meaningful conservation work. We assessed tree species distribution in Okwangwo Forest, Nigeria. Systematic sampling technique was adopted for plot selection. 24 transects, measuring 1000m long at 500 m intervals were laid. Four sample plots of 0.25 ha were located alternately at 250m intervals along each transect, making 96 plots (24 ha) in all. The diameters of all the trees with dbh .10 cm were measured. All measured trees were identified to species level. Data were analyzed using descriptive statistics such as means, frequencies, percentages and charts. Also, species relative densities and  richness were computed. Tree species were grouped into abundance classes. A total of 125 tree  species belonging to 36 families and 96 genera were recorded in the area with Margaleffs index of species richness of 2.2754. Most (99) of the tree species  encountered were threatened/endangered, 23 species were rare with only 3 tree species (Brachystegia eurycoma, Bailonella toxisperma and Ceiba pentandra)  being  abundant in the area. Frequent and occasional species were not encountered in the area. Leguminoseae  was the most represented family  with 14.84% (19  species) with Styraceae, Polygonaceae,  Papilionioideae, Sapindaceae, Connaraceae, Flacourtiaceae, Tiliaceae, Asparagaceae, Ochnaceae,  Bignoniaceae,  Mimosoideae, Piperaceae, Anisophyllaceae and Violaceae being the least with one species each. The mean basal area of 111.32 m2/ha recorded in the area was higher than the value suggested for a well-stocked and managed forest in Nigeria. There were more trees in the lower diameter classes than in the larger classes. The result of soil physical and chemical properties was also impressive with potential for site quality improvement going by the good stand structure

Enterotoxicigenicity profile of Escherichia coli, Vibrio, and Salmonella species isolated from well and river water sources in Oproama town in the Niger Delta, Nigeria

Well water is the only source of drinking water in Oproama Town in Rivers state, Nigeria. Water from these sources is consumed without treatment, and potentially poses a health risk to the local population. The Enterotoxigenicity profile of Escherichia coli, Vibrio and Salmonella species isolated from well and river water sources in Oproama were investigated using fluid accumulation (FA) ratio. The study revealed that Salmonella isolate (S9) from the river showed doubtful toxicity out of the ten Escherichia coli, ten Vibrio and ten Salmonella isolates. This study revealed a near-absence of enterotoxigenic Escherichia coli, Vibrio and Salmonella organisms from the waters in Oproama. More studies are required to further test the overall safety of these water sources due to the potential risk of consuming untreated water. KEYWORDS: Escherichia coli, Vibrio, Salmonella, Enterotoxigenicit

Conference summary report of the 10th Annual General and Scientific Meeting of the Nigerian Society of Neonatal medicine (NISONM) held in Ibadan, Nigeria on 4th -7th July, 2017

The 10th Annual General and Scientific Meeting (AGSM) of the Nigerian Society of Neonatal Medicine (NISONM) took place in Ibadan, South -West Nigeria. The theme of the conference was: Imperatives in neonatal survival initiatives in Nigeria: The current state. The conference addressed a variety of topics relevant to newborn health from eminent speakers from across the globe. The four-day conference included preconference workshops and community mobilization/ health outreach in Lagelu local government area

Cosmic Ray Anomalies from the MSSM?

The recent positron excess in cosmic rays (CR) observed by the PAMELA satellite may be a signal for dark matter (DM) annihilation. When these measurements are combined with those from FERMI on the total ($e^++e^-$) flux and from PAMELA itself on the $\bar p/p$ ratio, these and other results are difficult to reconcile with traditional models of DM, including the conventional mSUGRA version of Supersymmetry even if boosts as large as $10^{3-4}$ are allowed. In this paper, we combine the results of a previously obtained scan over a more general 19-parameter subspace of the MSSM with a corresponding scan over astrophysical parameters that describe the propagation of CR. We then ascertain whether or not a good fit to this CR data can be obtained with relatively small boost factors while simultaneously satisfying the additional constraints arising from gamma ray data. We find that a specific subclass of MSSM models where the LSP is mostly pure bino and annihilates almost exclusively into $\tau$ pairs comes very close to satisfying these requirements. The lightest $\tilde \tau$ in this set of models is found to be relatively close in mass to the LSP and is in some cases the nLSP. These models lead to a significant improvement in the overall fit to the data by an amount $\Delta \chi^2 \sim 1/$dof in comparison to the best fit without Supersymmetry while employing boosts $\sim 100$. The implications of these models for future experiments are discussed.Comment: 57 pages, 31 figures, references adde

Decaying Dark Matter in the Supersymmetric Standard Model with Freeze-in and Seesaw mechanims

Inspired by the decaying dark matter (DM) which can explain cosmic ray anomalies naturally, we consider the supersymmetric Standard Model with three right-handed neutrinos (RHNs) and R-parity, and introduce a TeV-scale DM sector with two fields \phi_{1,2} and a $Z_3$ discrete symmetry. The DM sector only interacts with the RHNs via a very heavy field exchange and then we can explain the cosmic ray anomalies. With the second right-handed neutrino N_2 dominant seesaw mechanism at the low scale around 10^4 GeV, we show that \phi_{1,2} can obtain the vacuum expectation values around the TeV scale, and then the lightest state from \phi_{1,2} is the decay DM with lifetime around \sim 10^{26}s. In particular, the DM very long lifetime is related to the tiny neutrino masses, and the dominant DM decay channels to \mu and \tau are related to the approximate \mu-\tau symmetry. Furthermore, the correct DM relic density can be obtained via the freeze-in mechanism, the small-scale problem for power spectrum can be solved due to the decays of the R-parity odd meta-stable states in the DM sector, and the baryon asymmetry can be generated via the soft leptogensis.Comment: 24 pages,3 figure

Decaying into the Hidden Sector

The existence of light hidden sectors is an exciting possibility that may be tested in the near future. If DM is allowed to decay into such a hidden sector through GUT suppressed operators, it can accommodate the recent cosmic ray observations without over-producing antiprotons or interfering with the attractive features of the thermal WIMP. Models of this kind are simple to construct, generic and evade all astrophysical bounds. We provide tools for constructing such models and present several distinct examples. The light hidden spectrum and DM couplings can be probed in the near future, by measuring astrophysical photon and neutrino fluxes. These indirect signatures are complimentary to the direct production signals, such as lepton jets, predicted by these models.Comment: 40 pages, 5 figure

Effective Dark Matter Model: Relic density, CDMS II, Fermi LAT and LHC

The Cryogenic Dark Matter Search recently announced the observation of two signal events with a 77% confidence level. Although statistically inconclusive, it is nevertheless suggestive. In this work we present a model-independent analysis on the implication of a positive signal in dark matter scattering off nuclei. Assuming the interaction between (scalar, fermion or vector) dark matter and the standard model induced by unknown new physics at the scale $\Lambda$, we examine various dimension-6 tree-level induced operators and constrain them using the current experimental data, e.g. the WMAP data of the relic abundance, CDMS II direct detection of the spin-independent scattering, and indirect detection data (Fermi LAT cosmic gamma-ray), etc. Finally, the LHC reach is also explored

Phenomenology of Dark Matter from A4 Flavor Symmetry

We investigate a model in which Dark Matter is stabilized by means of a Z2 parity that results from the same non-abelian discrete flavor symmetry which accounts for the observed pattern of neutrino mixing. In our A4 example the standard model is extended by three extra Higgs doublets and the Z2 parity emerges as a remnant of the spontaneous breaking of A4 after electroweak symmetry breaking. We perform an analysis of the parameter space of the model consistent with electroweak precision tests, collider searches and perturbativity. We determine the regions compatible with the observed relic dark matter density and we present prospects for detection in direct as well as indirect Dark Matter search experiments.Comment: 15 pages, 4 figures.v2: minor modifications, matches version accepted for publication in JHE

Right-handed Sneutrino Dark Matter in Supersymmetric B-L Model

We show that the lightest right-handed sneutrino in TeV scale supersymmetric B-L model with inverse seesaw mechanism is a viable candidate for cold dark matter. We find that it accounts for the observed dark matter relic abundance in a wide range of parameter space. The spin-independent cross section of B-L right-handed sneutrino is consistent with the recent results CDMS II and XENON experiments and it is detectable in future direct detection experiments. Although the B-L right-handed sneutrinos annihilate into leptons, the PAMELA results can not be explained in this model unless a huge boost factor is considered. Also the muon flux generated by B-L right-handed sneutrino in the galactic center is smaller than Super-Kamiokande's upper bound.Comment: 16 pages, 7 figures; version accepted for publication in Journal of High Energy Physic