Application of remote sensing technique in biomass change detection: a case study of Bromley and Chihota, Zimbabwe

Biomass is defined as the total mass of living plant matter in a given unit of an environment area.  Several factors influence the change in biomass content of an area. The rate of change varies from mass seasonal drying of grasslands to gradual degradation of forestry area.  It is in the interest of environmental monitoring and sustainable development that biomass change be constantly determined. There are various field methods used worldwide to determine density of forest resources but have several limitations because of the nature of factors influencing biomass change.  These include seasonal changes, human activities, forest fires etc.  Remote Sensing as an enabling technology provides an efficient avenue of assessment of biomass content of any area.  This research focused on biomass content that constituted forest resources. Two main methods used were qualitative analysis involving visual image interpretation relying on knowledge of spectral reflectance characteristics of ground cover types and quantitative analysis involving use of mathematical capacity of the computer to extract information on pixel digital number The techniques employed in these methods were complementary and were combined in a systematic manner to optimize the potential of remotely sensed data in biomass change. Comparison of two methods information, revealed that biomass content obtained from the remotely sensed data from the two study areas were almost identical. Extra ancillary data like population information and detailed land use data, can be integrated into GIS together with results from remote sensing analysis to enhance the decision making process.Keywords:  Biomass, Forest, Image, Interpretation, Qualitative, Quantitativ

Flexoelectricity and pattern formation in nematic liquid crystals

We present in this paper a detailed analysis of the flexoelectric instability of a planar nematic layer in the presence of an alternating electric field (frequency $\omega$), which leads to stripe patterns (flexodomains) in the plane of the layer. This equilibrium transition is governed by the free energy of the nematic which describes the elasticity with respects to the orientational degrees of freedom supplemented by an electric part. Surprisingly the limit $\omega \to 0$ is highly singular. In distinct contrast to the dc-case, where the patterns are stationary and time-independent, they appear at finite, small $\omega$ periodically in time as sudden bursts. Flexodomains are in competition with the intensively studied electro-hydrodynamic instability in nematics, which presents a non-equilibrium dissipative transition. It will be demonstrated that $\omega$ is a very convenient control parameter to tune between flexodomains and convection patterns, which are clearly distinguished by the orientation of their stripes

A spatially based field specific crop recordkeeping system prototype for farmers

The purpose of this study was to develop a spatially based application that is able to capture, query, update and maintain crop production historical records for each field. Maps of the farm showing the fields were made. The fields were then numbered. These spatial data were prepared using ArcGIS 9.3. A database was created in Microsoft Access 2007. The database contained information on crops, fertilizers and past management. The information was linked to the spatial data table and maintained in the database. An application was developed using Visual Basic 6 in Map Objects allowing for the manipulation of spatial data within the visual basic environment. Results have shown that a record keeping system may link crop records to respective mapped crop fields in a GIS environment. This was then used to view crop field area, update new field data in the non spatial database and query and display field data for a specified period of interest. New data were added to their respective tables whenever available.Keywords:  Recordkeeping system, Crop field, spatial, Farm, Management, Applicatio

Religious service attendance and spiritual well-being are differentially associated with risk of major depression

Background: The complex relationships between religiosity, spirituality and the risk of DSM-IV depression are not well understood. Method: We investigated the independent influence of religious service attendance and two dimensions of spiritual well-being (religious and existential) on the lifetime risk of major depression. Data came from the New England Family Study (NEFS) cohort (n=918, mean age=39 years). Depression according to DSM-IV criteria was ascertained using structured diagnostic interviews. Odds ratios (ORs) for the associations between high, medium and low tertiles of spiritual well-being and for religious service attendance and the lifetime risk of depression were estimated using multiple logistic regression. Results: Religious service attendance was associated with 30% lower odds of depression. In addition, individuals in the top tertile of existential well-being had a 70% lower odds of depression compared to individuals in the bottom tertile. Contrary to our original hypotheses, however, higher levels of religious well-being were associated with 1.5 times higher odds of depression. Conclusions: Religious and existential well-being may be differentially associated with likelihood of depression. Given the complex interactions between religiosity and spirituality dimensions in relation to risk of major depression, the reliance on a single domain measure of religiosity or spirituality (e.g. religious service attendance) in research or clinical settings is discouraged