Estimating Population Attribute Values in a Table: “Get Me Started in” Iterative Proportional Fitting

Iterative proportional fitting (IPF) is a technique that can be used to adjust a distribution reported in one data set by totals reported in others. IPF is used to revise tables of data where the information is incomplete, inaccurate, outdated, or a sample. Although widely applied, the IPF methodology is rarely presented in a way that is accessible to nonexpert users. This article fills that gap through discussion of how to operationalize the method and argues that IPF is an accessible and transparent tool that can be applied to a range of data situations in population geography and demography. It offers three case study examples where IPF has been applied to geographical data problems; the data and algorithms are made available to users as supplementary material.     

Stormflow generation involving pipe flow in a zero‐order basin of Peninsular Malaysia

Hydrological responses in a zero‐order basin (ZOB), a portion of whose discharge emerged via preferential flow through soil pipes, were examined over a 2‐year period in Peninsular Malaysia to elucidate primary stormflow generation processes. Silicon (Si) and specific conductance (EC) in various runoff components were also measured to identify their sources. ZOB flow response was dependent on antecedent precipitation amount; runoff increased linearly with precipitation during events >20 mm in relatively wet antecedent moisture conditions. Runoff derived from direct precipitation falling onto saturated areas accounted for <0·2% of total ZOB flow volume during the study period, indicating the predominance of subsurface pathways in ZOB flow. ZOB flow (high EC and low Si) was distinct from perennial baseflow via bedrock seepage (low EC and high Si) 5 m downstream of the ZOB outlet. Pipe flow responded quickly to ZOB flow rate and was characterized by a threshold flow capacity unique to each pipe. Piezometric data and pipe flow records demonstrated that pipes located deeper in the soil initiated first, followed by those at shallower depths; initiation of pipe flow corresponded to shallow groundwater rise above the saprolite‐soil interface. Chemical signatures of pipe flow were similar to each other and to the ZOB flow, suggesting that the sources were well‐mixed soil‐derived shallow groundwater. Based upon the volume of pipe flow during storms, the combined contribution of the pipes monitored accounted for 48% of total ZOB flow during the study period. Our results suggest that shallow groundwater, possibly facilitated by preferential flow accreted above the saprolite–soil interface, provides dominant stormflow, and that soil pipes play an important role in the rapid delivery of solute‐rich water to the stream system. Copyright © 2006 John Wiley & Sons, Ltd.     

Metabolic and physiological regulation of Chlorella sp.(Trebouxiophyceae,Chlorophyta) under nitrogen deprivation

A freshwater green microalgae Chlorella sp., UMACC344 was shown to produce high lipid content and has the potential to be used as feedstock for biofuel production. In this study, photosynthetic effciency, biochemical pro?les and non-targeted metabolic pro?ling were studied to compare between the nitrogen-replete and deplete conditions. Slowed growth, change in photosynthetic pigments and lowered photosynthetic effciency were observed in response to nitrogen deprivation. Biochemical pro?les of the cultures showed an increased level of carbohydrate, lipids and total fatty acids, while the total soluble protein content was lowered. A trend of fatty acid saturation was observed in the nitrogen-deplete culture with an increase in the level of saturated fatty acids especially C16:0 and C18:0, accompanied by a decrease in proportions of monounsaturated and polyunsaturated fatty acids. Fifty-nine metabolites, including amino acids, lipids, phytochemical compounds, vitamins and cofactors were signi?cantly dysregulated and annotated in this study. Pathway mapping analysis revealed a rewiring of metabolic pathways in the cells, particularly purine, carotenoid, nicotinate and nicotinamide, and amino acid metabolisms. Within the treatment period of nitrogen deprivation, the key processes involved were reshu ? ing of nitrogen from proteins and photosynthetic machinery, together with carbon repartitioning in carbohydrates and lipids.     

Treatment of broad palaeodose distributions in OSL dating of dune sands from the western Murray Basin, South Australia

Preliminary results of an optically stimulated luminescence dating study in the western Murray Basin in semi-arid south-eastern Australia are presented. The ultimate objective of the dating study is a reconstruction of dune formation indicative of palaeoclimatic changes in this region. So far, one site has been dated using the single-aliquot regenerative (SAR) dose protocol for quartz. A high scatter in individual palaeodoses was observed, which is unexpected in supposedly well bleached aeolian deposits. Therefore other sources of variability such as microdosimetry and bioturbation have to be taken into account. Nevertheless, the resulting ages are in chronostratigraphic order and document a long aeolian record from 180 to 9 ka.     

Spatio-temporal distribution of seismic activity during the Umbria-Marche crisis, 1997

We present the spatio-temporal distribution of more than 2000 earthquakesthat occurred during the Umbria-Marche seismic crisis, between September 26and November 3, 1997. This distribution was obtained from recordings of atemporary network that was installed after the occurrence of the first two largest shocks (Mw =, 5.7, Mw = 6.0) of September 26. This network wascomposed of 27 digital 3-components stations densely distributed in theepicentral area. The aftershock distribution covers a region of about 40 km long and about2 km wide along the NW-SE central Apennines chain. The activity is shallow,mostly located at less than 9 km depth. We distinguished three main zonesof different seismic activity from NW to SE. The central zone, that containsthe hypocenter of four earthquakes of magnitude larger than 5, was the moreactive and the more complex one. Sections at depth identify 40–50^°dipping structures that agree well with the moment tensor focalmechanisms results. The clustering and the migration of seismicity from NW to SE and the generalfeatures are imaged by aftershock distribution both horizontally and at depth.     

OSL Age Determination of Archaeological Stone Structures Using Trapped Aeolian Sediments: A Case Study from the Negev Highlands,Israel

Optically stimulated luminescence (OSL) dating is widely applied to sediments in paleoenvironmental sciences. However, there are only limited examples determining the age of archaeological stone structures by OSL using dust deposits. The age of dust deposits associated with ancient buildings may be used to date the onset of settlement (sediment below structures), settlement activity (occupation layer), or the time after a settlement had been abandoned or destroyed (sediment between collapsed roofs and walls). In this study, OSL dating is applied to establish numerical dates for settlement structures situated in the Negev Highlands, Israel. Two archaeological sites are investigated to identify their occupation history, by dating nine samples of aeolian dust trapped within the remains of ancient buildings. The OSL dating technique is applied using coarse grain quartz and a standard single‐aliquot regenerative‐dose (SAR) protocol. It was possible to date the onset of sedimentation in a later phase of the human occupation or shortly after the sites were abandoned, to 3.7 ± 0.3 ka (Intermediate Bronze Age) at the central site and to 2.7 ± 0.2 ka (Iron Age) at the ephemeral site. These results are supported by archaeological evidence gained from pottery finds and the architecture of the ancient buildings.     

The study of mercury pollution distribution around a chlor-alkali petrochemical complex, Bandar Imam, southern Iran

Sewage outflow resulting from a chlor-alkali unit of Bandar Imam Petrochemical Complex (BIPC) has been released into the Persian Gulf (Khoor Moosa) for many years, leading to seawater contamination and finally influencing the ecological conditions and the marine ecosystem. In this study, in order to determine the distribution pattern of contaminated points in sea sediments, 15 stations were selected for Hg-content determination in sediments regarding its distribution and relation with contaminant source inflow into the sea. The Hg content of the samples ranged from 0.03 to 103.7 ppm, the maximum of which was detected in a sample collected from a depth of 0–10 cm, somewhere close to a sewage outflow channel of a chlor-alkali unit. Hg content of sediments had a meaningful relationship with chlor-alkali unit outflow volume. As geological setting within the area cannot provide the water with the present level of mercury, the resulting contamination should be due to BIPC activity.     

Hydraulic Conductivity of Compacted Granite Residual Soil Mixed with Palm Oil Fuel Ash in Landfill Application

Laboratory tests were carried out on compacted granite residual soil treated with 0 to 15% Palm Oil Fuel Ash (POFA), with a view to evaluate its hydraulic conductivity for its application in landfilling. The Soil–POFA mixtures were compacted using both Standard and Modified Proctors compactive efforts at 2% dry of Optimum Moulding water Content (?2%), at Optimum Moulding water Content (0%), at 2 and 4% on the wet side of Optimum Moulding water Content (+2 and +4%). The samples were permeated with water and the effect of moulding water content; compactive effort and POFA content were examined. The samples that met the minimum threshold of 1 × 10^?9 m/s were used in plotting the acceptable zones criterion at various POFA mixtures. The results gave indications of reduction in the hydraulic conductivity values, with increase in compactive efforts, moulding water content and POFA content up to about 10%. This was the most suitable soil–POFA mixture for the hydraulic application.     

Behavioral of sediment transport at lowland and mountainous rivers: a special reference to selected Malaysian rivers

Mountain rivers and lowland rivers differ in many ways. Some of the many elements that distinguish both river systems apart are the rivers’ geomorphological appearances, hydraulic geometry, pollution transport, sediment transport, and its own roughness and coarseness. In this particular study, the element of sediment transport is given distinctive attention too. This study employs the deterministic approach for bed load prediction entailing the use of the parameterization concept where particle size and flow variation is taken into full consideration. Apart from that, the classical approach of Shields number is also used to determine the transport rates at the fluvial system. However, due to some limitation and range of applicability, the Shields number approach was re-modified to suit the range of applicability. Changes were made to the alleviating critical stress term and formulating exponential approach. For this research, it was important to deduce the underlying principles which are universal and common to all river systems, due to obvious and distinct differences between the mountain and lowland rivers. A special attribute was given to the Malaysian natural rivers because of the limited recorded data available. All datasets were compiled and tested with the bed load predictors to observe the commonality pattern between the lowland and mountain river systems. Most of the bed load transport equations limit the range of applicability by isolating the flow regime or bed roughness individually. Thus, it was vital for researchers to find the commonality pattern between these two river systems which needed to be statistically sound in its form. It was postulated that the particle densimetric Froude number is graphically and statistically fit for both river systems. Hence, this predictor is used as it has a high potential to be included in the sediment transport parameterization for Malaysian natural rivers.