Modeling a habitat suitability index for the eastern fall cohort of Ommastrephes bartramii in the central North Pacific Ocean

The eastern fall cohort of the neon flying squid, Ommastrephes bartramii, has been commercially exploited by the Chinese squid jigging fleet in the central North Pacific Ocean since the late 1990s. To understand and identify their optimal habitat, we have developed a habitat suitability index （HSI） model using two potential important environmental variables -- sea surface temperature （SST） and sea surface height anomaly （SSHA） -- and fishery data from the main fishing ground （165°-180°E） during June and July of 1999-2003. A geometric mean model （GMM）, minimum model （MM） and arithmetic weighted model （AWM） with different weights were compared and the best HSI model was selected using Akaike＇s information criterion （AIC）. The performance of the developed HSI model was evaluated using fishery data for 2004. This study suggests that the highest catch per unit effort （CPUE） and fishing effort are closely related to SST and SSHA. The best SST- and SSHA-based suitability index （SI） regression models were SISST-based = 0.7SIeffort-SST ＋ 0.3 SICPUE-SST, and SISSHA-based =0.5Sleffort-SSHA ＋ 0.5SICPUE-SSHA, respectively, showing that fishing effort is more important than CPUE in the estimation of SI. The best HSI model was the AWM, defined as HSI=0.3SISSHA-based＋ 0.7SISSHA-based, indicating that SSHA is more important than SST in estimating the HSI of squid. In 2004, monthly HSI values greater than 0.6 coincided with the distribution of productive fishing ground and high CPUE in June and July, suggesting that the models perform well. The proposed model provides an important tool in our efforts to develop forecasting capacity of squid spatial dynamics.

Diagenetic and geochemical studies of the Buchan Formation (Upper Devonian) in the Central North Sea

The Upper Devonian Buchan Formation reservoirs in the UK Central North Sea are litharenite/sublitharenite and were deposited in fluvial-aeolian settings. The grain-coating clays in the aeolian sandstones have effectively inhibited quartz overgrowth. Hence, the reduction of reservoir quality is mainly due to mechanical compaction and early dolomite pre- cipitation in both fluvial and aeolian sandstones; quartz overgrowth and kaolinite illitization in fluvial sandstones; and limited smectite illitization in aeolian sandstones. The carbon/oxygen stable isotopes of dolomite cements suggest a predominantly marine carbon source and precipitation temperatures between 25 and 58 ~C indicating a shallow burial depth during dolomite precipitation. The temperatures and the dolomite distribution indicate that the cements originated from the overlying Upper Permian Zechstein carbonates. Extensive quartz overgrowths formed at 80 and 120 ~C in the late and deep diagenetic burial history. The most probable silica source was from feldspar kaolinitization and pressure dissolution of quartz grains. Through detailed petrography and geochemical analyses, the burial-paragenesis-thermal history of the Buchan Formation has been constructed. Similar diagenetic processes are likely to have occurred in the Buchan Formation in other parts of the Central and Northern North Sea. This study may allow new petroleum plays to be considered in areas previously thought to have poor hydrocarbon potential.

Comparative analysis of interdecadal precipitation variability over central North China and sub Saharan Africa

The interdecadal variability of precipitation over sub-Saharan Africa (SSA) and central North China (CNC) is examined and compared in this study. Previous studies have found that the two regions have similar interdecadal dry–wet evolution in the past 100 years. The results show obvious decadal precipitation fluctuations in the two regions. In CNC, a persistent negative precipitation anomaly is detected from the early 1970s to the 2000s. In SSA, a negative precipitation anomaly is apparent since the late 1970s, while a distinct upward trend is found since the 1990s although the precipitation anomaly is still negative. Significant correlation is found between the decadal precipitation anomalies in SSA and the SST modes (Atlantic Multidecadal Oscillation (AMO) and Pacific Decadal Oscillation (PDO)), as well as the North Atlantic Oscillation (NAO), while in CNC the decadal precipitation is influenced by the NAO and PDO. The EOF results show that the total explained variance of the first four EOFs in SSA is smaller than that of CNC. The fourth and third modes in SSA are significantly associated with the AMO and PDO respectively, while the first, third, and fourth modes are significantly associated with the NAO. The first mode in CNC is significantly associated with the NAO. The first mode of the precipitation anomaly in SSA fluctuates out of phase with that in CNC, while in-phase changes are apparent among the third and the fourth modes.

Facies Architecture of the Fluvial-Aeolian Buchan Formation (Upper Devonian) and Its Implications on Field Exploration: A Case Study from Ardmore Field, Central North Sea, UK

The Upper Devonian Buchan Formation in the Central North Sea is a typical terrestrial deposit and predominantly comprises fine to medium-grained sandstones with occasional conglomerates and mudstones. The Buchan Formation has been previously described as being made up mostly of braided fluvial sandstones;however, this study confirms the presence and significance of aeolian sandstones within this fluvial-dominated sequence. Facies architecture is investigated through analogue outcrop study, well log curves and numerical facies modelling, and the results show contrasting differences between fluvial and aeolian facies. The fluvial facies is composed of multiple superimposed and sand-dominated fining-upward cycles in the vertical direction, and laterally an individual cycle has a large width/thickness ratio but is smaller than the field scale. However, the high channel deposition proportion (CDP, average value = 72%) in fluvial-dominated intervals means that it is likely all the sand bodies are interconnected. Aeolian facies comprise superimposed dune and interdune depositions and can be laterally correlated over considerable distances (over 1 km). Although the aeolian sandstones are volumetrically minor (approx. 30%) within the whole Buchan Formation, they have very high porosity and permeability (14.1% - 28%, 27 - 5290 mD) and therefore are excellent potential reservoirs. The fluvial sandstones are significantly cemented by quartz overgrowth and dolomite and by comparison with the aeolian sandstones are poor reservoirs. Aeolian sandstones can be differentiated from fluvial sandstones using several features: pin-stripe lamentation, good sorting, high visible porosity, friable nature and lack of muddy or conglomeratic contents;these characteristics allow aeolian sandstones can be tentatively recognized by low gamma ray values, high sonic transit time and low density in uncored wells. The thin, laterally correlatable and permeable aeolian sandstones within the Buchan Formation are effective reservoirs and could form important exploration targets when the Devonian is targeted elsewhere in the North Sea.

Comparison of trends and frequencies of drought in central North China and sub- Saharan Africa from 1901 to 2010

This study compares the trends and frequencies of drought between central North China(CNC) and(SSA) for the periods 1901–2010 and 1951–2010. The Standardized Precipitation Evapotranspiration Index(SPEI) and Self-Calibrating Palmer Drought Severity Index(sc-PDSI) are used to assess the drought trends and frequencies. In general, the results exhibit downward trends of drought index values and upward trends of drought frequencies over CNC and SSA. A high rate of the trends' slopes for the drought index and a low rate of the frequencies' slopes is found over CNC with respect to SPEI and sc-PDSI. Furthermore, some abrupt changes are revealed after applying the sequential Mann–Kendall test to detect change points. These findings offer insight into the trends and frequencies of drought over the regions studied. Further analysis needs to be undertaken to understand the mechanisms underlying the occurrence of drought in these areas.

Neodymium isotopes distribution and transport in the central North Pacific deep water

Radiogenic Neodymium (Nd) isotopes in the central North Pacific deep water have been generally interpreted as reflecting Pacific arcs input according to previous studies,while little is known about the specific path and mode of radiogenic Nd from these arcs to deep water.In this study,Nd isotopic data from surface scrapings of 17 Fe-Mn crusts from the central North Pacific deep water (around 20°N) have been reported.Based on these data together with recently published data on dissolved Nd isotopes in seawater for this region,we propose that radiogenic Nd isotopes in North Pacific Intermediate Water (NPIW 300-800 m) from the western Pacific margin is an important source for the central North Pacific deep water,while the surface water of this area has little influence on dominating deep water Nd isotopes.Such a view emphasizes the role of vertical mixing and advection of the marginal ocean currents in balancing Nd isotopes in central North Pacific deep water,and helps to understand oceanic Nd cycling.Moreover,the values of Nd from surface scrapings of Fe-Mn crusts are relatively homogenous,with an average value of about-3.4,which is higher than that of modern seawater (～-3.9).This difference over short time scales reflects the quick evolution of Nd isotopes in central North Pacific deep water.

Prioritization of Water Resources Management Problems in North Central Nigeria Using Rapid Impact Assessment Matrix (RIAM)

This study employed the Rapid Impact Assessment Matrix (RIAM) to prioritize the water resources management problems in the North Central Nigeria. This was done through the assessment of the status of water resources management in the region, evaluation of existing policy and strategy of water management, identification of the management problems and the prioritization with RIAM. The stakeholders identified water resources management problems, ranked them in other of severity in different categories and also evaluated them using the RIAM techniques in the administered questionnaire. Eleven problems were analyzed based on the physical/chemical, biological/ecological, social/cultural and economic/operational factors using several impact indicators. Scores were assigned, the RIAM models applied and the averages taken to arrive at the final assessment scores. The two major water resources management problems identified are: 1) inadequate funds for further agricultural, hydroelectric, navigation and industrial development;2) poor data collection and banking. These problems were prioritized by RIAM in order of severity for urgent intervention. The RIAM technique has made a key contribution to the prioritization of water resources management by providing insights into urgent problems according to stakeholders and thus guides the policy maker in appropriate decision making.

Petrology and geochemical characteristics of Precambrian granitic basement complex rocks in the southernmost part of North-Central Nigeria

The Precambrian basement complex in the southernmost part of North-Central Nigeria is underlain by migmatitic banded gneisses, granitic intrusions and dykes of dolerite, rhyolite porphyry and pegmatite. The rocks are generally felsic, containing modal and normative hypersthene, as well as normative corundum. The basement complex has experienced high-grade regional metamorphism as indicated by the presence of hypersthene and plagioclase of andesine composition. Anatectic melting is suggested by the occurrence of ptygmatic folds, folded gneissose foliation, numerous quartzo-feldspathic veins and lenses of dark-colured, micaceous schistose rocks. Geochemically, the rocks have magnesian, calc-alkalic and strongly peraluminous characteristics. Their overall characteristics suggest derivation from progressive (fractional) partial melting of pelitic rocks during high-grade regional metamorphism, possibly associated with intense hydrothermal activities. The magnesian characteristics reflect close affinity to relatively hydrous, oxidizing melts and source regions in settings broadly related to subduction.

Diagnostic Analysis on a Regional Rainstorm Weather in North-central Henan Province

[Objective] The research aimed to analyze a regional rainstorm weather process in north-central Henan Province. [Method] Based on the conventional meteorological observation data and the rainfall data of Henan Meteorological Station, the diagnostic analysis of atmospheric thermodynamics and dynamics on a rainstorm weather process in north-central Henan Province on July 19, 2010 was carried out. The characteristics of physical quantity field and the evolution of weather situation in north-central Henan Province when the rainstorm happened were studied. [Result] Western Pacific subtropical high strengthened to extend westward. The dynamic uplifting of low vortex at the middle and low layers, the strong water vapor transportation of southwest low-level jet caused the regional rainstorm weather process in north-central Henan Province. The diagnostic results of physical quantity showed that the deep, thick wet layer and the sustained water vapor convergence provided the abundant water vapor for rainstorm generation. The positive vorticity advection center developed and spread from northwest to southeast, which was favorable for the development of vertical movement. The structure maintenance of positive vorticity at the middle and low layers, negative vorticity at the middle and high levels provided the power condition for the regional rainstorm generation. The pumping effect of convergence at the middle and low layers, divergence at the high layer was favorable for the strengthening of vertical ascending motion at the low layer. The uplifting effect of dew point front at the middle and low layers triggered the release of unstable energy. The confrontation of warm and cold air was one of the important reasons for the regional rainstorm. TBB characteristic analysis showed that TBB was from -60 to -50 ℃ in north-central Henan Province in the whole strong precipitation time, and the moving speed was equivalent to that of southwest vortex. The low-value belt of TBB corresponded with the rainstorm occurrence zone in Henan, and the minimum-value center of TBB was basically consistent with the strongest center of precipitation. [Conclusion] The research provided the scientific basis for the short-term forecast of rainstorm.

An Eight-Year Review of the Frequency and Outcome of Dog Bite and Clinical Rabies in a Teaching Hospital in North Central Nigeria

Introduction: Rabies is a neglected tropical disease that is highly fatal and yet it is under-reported in the developing countries like Nigeria. The domestic dog is the primary reservoir host as well as the most important source of infection usually conveyed by saliva through bites. Aim: This study sought to determine the frequency and outcome of dog bite injury and clinical rabies presented to the Accident and Emergency unit of Benue State University Teaching Hospital Makurdi, Benue State, Nigeria. Methods: This retrospective hospital-based study reviewed the medical records of all patients with dog bite who presented over an eight-year period from August 2014 to July 2022. Rabies virus infection was diagnosed on clinical basis. A structured proforma was used to extract relevant information and data was analysed using the statistical package for social sciences (SPSS) version 21. Result: Mean and median age was 27.03 ± 10.98 and 29 years respectively, range of 2 - 47 years and 11 (73.3%) were males. There were 15 cases of dog bite out of 17,187 patients making frequency of 1.14 per 1000 persons constituting 0.09% or about 2 cases yearly. Seven (46.7%) of this total number had clinical rabies infection with 7 (100.0%) mortality. All 7 (100.0%) with clinical rabies had a furious (encephalitic) form. Rabies immunoglobulin was prescribed in 8 (53.3%), 6 (40.0%) received them while 13 (86.7%) received post-exposure rabies vaccine. Conclusion: Dog bite is an uncommon reason for Accident and Emergency visit in our facility with male preponderance. However, about 46.7% of the dog bite victims developed clinical symptoms suggestive of furious (encephalitic) form of rabies with 100.0% fatality.

ON THE DIFFERENTIATION OF THE ECONOMIC DEVELOPMENT OF CHINA’S NORTH,CENTRAL & SOUTH COASTAL REGIONS

Ⅰ. An analysis of the development trend of the economy in the north,middle aud south coastal regions or China since China began to implementreform and open

Hydrographic structure and circulation in the central area of the North Eastern Atlantic

-On the basis of the hydrographic data observed within the Canary Basin in autumn 1985, temperature-salinity properties, distributions of water masses and barocltne flow field, as well as the volume transports in this area are described more detailly. The analyses indicate that the activity in the waters of the Canary Basin is mainly attributed to the interleaving and mixing between the originated water masses (e. g. Surface Water, North Atlantic Central Water, Mediterranean Water and Deep Water) and the modified water masses (Subpolar Mode Water, Labrador Sea Water and Antarctic Intermediate Water) from the outside of the study area and the variation of themselves. The east recirculation of the Subtropic Gyre in the North Atlantic consists of Azores Current and Canary Current.Azores Current is formed with several flow branches around the Azores Island, while the main flow lies at 35?N south of the Azores Island. It begins to diverge near the 15?W. The return flow found off the Portugal coast may be its northern branch. The southern invasion of the Labrador Sea Water and the Subpolar Mode Water are prevented by Azores front which serves an obvious boundary separating the North Western Atlantic (Central) Water and the North Eastern Atlantic (Central) Water.

Genetic diversity of Plasmodium falciparum isolates from naturally infected children in north-central Nigeria using the merozoite surface protein-2 as molecular marker

Objective: To characterize the genetic diversity of Plasmodium falciparum ( P. falciparum ) field isolates in children from Lafia, North-central Nigeria, using the highly polymorphic P. falciparum merozoite surface protein 2 (MSP-2) gene as molecular marker. Methods: Three hundred and twenty children were enrolled into the study between 2005 and 2006. These included 140 children who presented with uncomplicated malaria at the Dalhatu Araf Specialist Hospital, Lafia and another 180 children from the study area with asymptomatic infection. DNA was extracted from blood spot on filter paper and MSP-2 genes were genotyped using allele-specific nested PCR in order to analyze the genetic diversity of parasite isolates. Results: A total of 31 and 34 distinct MSP-2 alleles were identified in the asymptomatic and uncomplicated malaria groups respectively. No difference was found between the multiplicity of infection in the asymptomatic group and that of the uncomplicated malaria group ( P >0.05). However, isolates of the FC27 allele type were dominant in the asymptomatic group whereas isolates of the 3D7 allele type were dominant in the uncomplicated malaria group. Conclusions: This study showed a high genetic diversity of P. falciparum isolates in North-central Nigeria and is comparable to reports from similar areas with high malaria transmission intensity.

Knowledge, Attitude and Practice of Physicians in the Treatment of Hypertension in North-Central Nigeria

Background and Objectives: Hypertension is a global health hazard and most cases are first attended to by the physicians. Achieving a control will depend on the knowledge, attitude and practice of the physicians. We therefore determined the knowledge, attitude and practices of physicians on the detection and treatment of arterial hypertension in north-central Nigeria. Design and Methods: A cross-sectional study of 100 of the 250 physicians attending a continuing medical education lecture series in Bida was conducted using a pre-validated self administered questionnaire. Results: The mean age of the physicians was 41.05 ± 8.71 years and 59 (73.8%) were males. Forty-one (51.2%) of them have practiced for more than 10 years. Arterial hypertension was considered an important health problem by 93.8% of the physicians, 30% of them believed that it should not be referred to a specialist. Majority of the physicians request for urinalysis (96.2%), electrocardiogram (95.0%), fasting blood glucose (88.8%), blood urea nitrogen (98.8%) and fasting lipid profile (97.5%) to either assess target organ damage or associated co-morbid conditions. Fifty-seven (71.2%) of the physicians prescribe diuretics as the initial drug. However, the knowledge of the other drugs on initiation of therapy of mild uncomplicated hypertension was poor. The sources of information on arterial hypertension by physicians were scientific programs (73.8%), drug companies (38.8%) and journals in 11.3%. Conclusion: The knowledge, attitude and practice of physicians in the detection and management of hypertension were modest. Educative programs like continuing medical education, seminars, and conferences on cardiovascular disorders are advised to be organized regularly to strengthen these and update the physicians.

Analysis of Rainfall Variability Using Remote Sensing and GIS in North Central Nigeria

The importance of rainfall variability in successfully understanding the dynamics of climate change in any region cannot be overemphasized. This study examines rainfall variability in the North Central region including the Federal Capital Territory Abuja using remote sensing and geographic information system (GIS) application. The study employed satellite data basically from near real time data of Moderate Resolution Imaging Spectroradiometer (MODIS). Thereafter, the point data of rainfall was clipped to the shape file of Nigeria Boundary and interpolation using Inverse Distance Weight (IDW) was done to generate rainfall spatial maps from 2000-2017. The result reveal high temporal variation in rainfall particularly Niger, Plateau, Benue and Nassarawa states. The study therefore recommends close monitoring of periodic pattern of rainfall characteristics in the region by the Nigerian meteorological agency and to encourage farmers into drought tolerant and irrigation farming.

Comparative Assessment of the Proximate and Mineral Composition of <i>Cucumis sativus</i>L. and <i>Solanum aethiopicum</i>L. Fruit Samples Grown in South Eastern and North Central Regions of Nigeria Respectively

Studies were carried out to comparatively assess the proximate and mineral composition of Solanum aethiopicum L. and Cucumis sativus L. fruit samples grown in the South Eastern and North Central regions of Nigeria respectively, following standard analytical procedures and instrumentation. The mineral elements (Na, K, Zn and Ca) were determined using atomic absorption spectrophotometer after wet digestion of the samples while the proximate parameters (ash content, moisture content, crude fibre content, crude protein content, crude fat content and carbohydrate content) were determined in accordance with standard analytical procedures. The mean range of the moisture, crude fibre, crude protein, crude fat, ash and carbohydrate contents in the S. aethiopicum L. fruit samples grown in the North Central and South Eastern regions of Nigeria were 72.49 - 88.23, 2.15 - 3.67, 1.31 - 1.85, 0.43 - 0.76, 0.51 - 0.84 and 3.18% - 5.72% respectively. Additionally, the moisture, crude fibre, crude protein, crude fat, ash and carbohydrate contents in the Cucumis sativus L. fruit samples grown in the South Eastern and North Central regions of Nigeria, had mean range of values of 93.60 - 98.76, 0.53 - 0.77, 2.14 - 2.84, 0.29 - 0.46, 0.90 - 1.14 and 3.88% - 4.66% respectively. The range of mean values of Na, K, Zn and Ca in the S. aethiopicum L. fruit samples from the South Eastern and North Central regions of Nigeria were 0.36 - 0.57, 1.92 - 2.80, 0.84 - 1.01 and 0.43 - 0.61 μg/g respectively. Also, Na, K, Zn and Ca had mean range of values of 1.36 - 4.08, 10.16 - 13.09, 0.45 - 0.66 and 5.85 - 9.3 μg/g respectively in the C. sativus L. fruit samples grown in the South Eastern and North Central regions in Nigeria. The levels of the determined proximate of parameters and mineral elements in the studied fruit samples from the investigated regions of Nigeria were statistically significant. This therefore indicates that the geographical locations where these fruit samples grew could have significantly impacted on their nutrient content levels. The levels of the determined proximate parameters from the selected regions of Nigeria shows that consumption of the fruit samples (S aethiopicum L. and C. sativus L.) especially regularly, would help supply the essential nutrients and minerals required for a healthy living.

Geospatial Technology Potentials in Reawakening the Consciousness of Soil Distribution in Nigeria’s North-Central Region and Mediating the Herdsmen-Farmers Conflicts

The pervasive herdsmen-farmers conflicts in the north-central region of Nigeria have changed the narrative of Nigeria’s enduring ethnic crises to ideologies, which are in-controvertibly sinister. The consequences of this tension, which has defied possible military responses, political, religious and cultural strategies are potentially devastating, not just for Nigeria, but the whole of West African region. Since the particular nature of these conflicts increasingly highlights the significance and inevitability of land resources for crops farming and cattle rearing, it is imperative to create awareness of the elemental nature of soils, especially their diversities in these conflict-prone areas. This study’s objective was to produce a Geographic Information System (GIS) based digital soil map (DSM) of the north-central region of Nigeria, and to delineate soil distribution and unique properties. Based on this study, the DSM offers a quick access to quantitative soil data covering the study area. It indicates that soil mapping units 15d, 18d and 24b are dominant, and constitute about 40% of the local arable lands. The broad pattern of distribution of these soils reflects both the climatic conditions and the geological structure of the region. The soils are highly weathered with limited capacities to supply essential nutrients needed by crop plants. These issues raise a number of questions, most of which focuses on the best possible way to maximize these soils to accommodate both crop farming and cattle rearing. It is our hope that taking the advantage of GIS to stimulate the knowledge and consciousness of soil distribution in the region will place the weight where it is appropriate in terms of food security through crops production and cattle rearing, and hence forge a more realistic pathway to reconciliation and conflict resolution.

Comparative Assessment of the Phytochemical and Selected Heavy Metal Levels in <i>Cucumis sativus</i>L. and <i>Solanum aethiopicum</i>L. Fruit Sample Grown in South Eastern and North Central Regions of Nigeria Respectively

Studies were carried out to comparatively assess the phytochemical and heavy metal levels in Solanum aethiopicum L. and Cucumis sativus L. fruit samples grown in the South Eastern and North Central regions of Nigeria respectively using standard analytical procedures and instrumentation. The fruit samples were assayed for selected heavy metals (Pb, Cd and Cu) using atomic absorption spectrophotometer after wet digestion of the samples. The five detected phytochemicals (flavonoids, alkaloids, terpenoids, saponins and glycosides) were present at varying amounts in the investigated fruit samples from the South Eastern and North Central regions of Nigeria. The range of mean values of flavonoids, terpenoids, saponins and glycosides in the S. aethiopicum L. fruit samples from the two studied regions were 0.50 - 0.57, 0.53 - 1.26, 0.44 - 0.78, 1.12 - 1.93 and 0.40 - 0.50 mg/g respectively. The range of mean values of flavonoids, alkaloids, terpenoids, saponins and glycosides in the C. sativus L. fruit samples from the two studied regions of Nigeria were 1.27 - 1.69, 0.53 - 0.55, 0.96 - 1.51, 0.41 - 0.83 and 0.90 - 1.74 mg/g respectively. The range of mean vales of Pb, Cd, and Cu in the S. aethiopicum L. fruit samples from the two studied regions were 0.15 - 0.24, 0 - 0.01, 0.78 - 1.12 μg/g respectively. 0.31 - 0.40, 0.02 - 0.05 and 0.62 - 0.96 μg/g were the range of mean values of Pb, Cd and Cu respectively in the C. sativus L. fruit samples from the two studied regions of Nigeria. Of the three investigated heavy metals, only Cd was at toxic levels in the C. sativus L. fruit samples from the South Eastern and North Central regions of Nigeria. This is therefore a health concern to the fruit consumers that includes these fruits in their habitual daily fruit diets. Although the therapeutic and pharmaceutical benefits that would be derived from consuming, the investigated fruit samples has been shown in this study, there is therefore a possible risk of undue exposure to environmental pollutants such as heavy metal, especially through growing these fruits in polluted soils resulting from unwholesome anthropogenic practices. For fruit consumers to derive maximum health benefits from consuming these fruits, pollutants like heavy metals must be at non-toxic levels and this can only be achieved by ensuring that these fruits samples are grown and harvested in environments with less anthropogenic activities.

Assessment of Drought Vulnerability and Occurrence Zones in North Central Nigeria

Assessment of drought vulnerability and occurrence zones in North Central Nigeria was carried out in this study using standardized Precipitation Index (SPI). The Standardized Precipitation Index (SPI) 12 months’ time scale was computed from long-term rainfall data between 1960 and 2015 obtained from the Nigerian Meteorological Agency (NIMET) Abuja. The SPI results were further subjected to Mann-Kendal and Sen’s slope analysis for trend detection. To assess the vulnerability of drought and occurrence zones, the SPI and other geo-spatial techniques were employed to generate drought vulnerability maps for three epochs: 2000-2005, 2005-2010 and 2010-2015 respectively. The SPI values were interpolated using Inverse Weighted (IDW) techniques in ArcGIS10.5 to generate the vulnerability maps for the selected model years. The outcome of drought trend and vulnerability maps reveals increasing drought trend dominated by near normal and moderate conditions in Abuja, Ilorin and Lokoja while moderate and severe droughts were observed in Minna and Jos. The study therefore recommends holistic drought monitoring and management strategies in order to mitigate its adverse impact on water resources and rainfall-dependent agriculture.

湘中北晚二叠世石煤元素地球化学特征

湘中北地区晚二叠世吴家坪组赋存少量石煤,其属性特征鲜明。为揭示湘中北地区石煤元素地球化学特征,采集4个湘中北地区晚二叠世石煤样品,利用X射线衍射仪、带能谱的扫描电镜、X射线荧光光谱仪、电感耦合等离子质谱仪和逐级化学提取试验,测定了石煤样品的矿物成分、常量元素和微量元素含量,进行了微量元素赋存状态分析。结果表明:湘中北地区晚二叠世石煤高灰特征显著,石煤全硫含量差异性大,以硫化铁为主,有机硫次之;石煤矿物种类较少,以石英为主,陆源碎屑输入量极大;石煤高度富集V、Cr、As、Cd、Mo和Sb,其中Cd达到了上地壳丰度的555倍;石煤微量元素赋存特征复杂,其中Ni、Zn、Sr、Mo、Cd赋存状态多样,Li、V、Cr、Cu、Rb、Zr、Ba、U和REEs赋存状态相对简单;根据湘中北晚二叠世石煤元素地球化学特征认为石煤沉积于被动大陆边缘区域,接受陆源碎屑输入,沉积物源区以长英质酸性岩为主。石煤具有海相环境沉积物特征,沉积过程受海水影响强烈,相对稳定的缺氧环境,为V、Mo等元素自生富集提供了条件。