Recession Characteristics Research Articles

Can time domain and source area tracers reduce uncertainty in rainfall‐runoff models in larger heterogeneous catchments?

We used both time domain (deuterium) and source area (alkalinity) tracers to reduce uncertainty in simple conceptual rainfall‐runoff models applied to a larger (749 km2) heterogeneous catchment with both upland and lowland headwaters. Stepwise, tracer‐aided model development resulted in different model structures for the uplands and lowlands as representative elementary watersheds (REWs). These were differentiated by the parameterization of a nonlinear overland flow mechanism in the former, and the incorporation of high soil moisture storage capacity in the latter. Use of tracers and recession characteristics also helped to reduce parameter uncertainty and provided models that could simulate flows and tracer responses reasonably well over a full hydrological year. However, it was apparent that other processes (e.g., more complex mixing, fractionation, etc.) would need to be parameterized to explain the full variation in isotope dynamics. It is also evident that the information content of tracer data declines as the intensity of sampling decreases, particularly in the lowlands. The models of the REWs were coupled to provide plausible simulations of the up‐scaled flow and tracer response at the outfall of the 749 km2catchment, though the usefulness of source area tracers decreased markedly at this larger scale. Whereas the approach provides a step toward simple models that are likely to give the “right answer for the right reasons,” further improvements appear to require increased parameterization and/or higher‐resolution tracer data.

Safety Recession Characteristics of High Speed Milling Cutter

In order to research the influence property of pre-tightening force, centrifugal force and dynamic cutting force on cutter components, and reveal safety recession of the cutter components, this paper makes load analysis for high speed milling cutter, studies cutter deformation, joint surface crushing, ductile fracture and other damage characteristics, gets the safety recession order of cutter components by safety margin theory. By means of the grey correlation analysis for safety recession, acquires the safety recession model of cutter. The experiment results confirmed that screw component firstly occurs the safety recession, and the safety recession model has certain reliability.

Radiographic evaluation of Gustafson’s criteria for the purpose of forensic age diagnostics

The main criteria used in dental age estimation in living young individuals are mineralisation and eruption of the third molars. In order to further diversify the spectrum of characteristics after completion of third molar development, tests were undertaken to determine whether the characteristics studied by Gustafson can be ascertained with the required forensic certainty with the aid of the orthopantomogram and whether the evaluation of these could render forensic odontological age diagnoses possible beyond the 18th year of life. For this purpose, 1,299 conventionally produced orthopantomograms of 650 female and 649 male Germans aged from 15 to 40years were studied. The characteristics of secondary dentin formation, cementum apposition, periodontal recession and attrition were evaluated in all the mandibular premolars. The correlation of the individual characteristics with chronological age was studied with the aid of a multiple regression analysis in which chronological age formed the dependent variable. Depending on the tooth studied, the R values amounted to 0.65 to 0.73; the standard error of estimate was 5.3 to 5.7years. Basically, the regression equations calculated can be recommended for age estimation in living individuals, although it should be borne in mind that the applicability of the new method presented is limited by the quality of the X-ray images.

Peak flow responses and recession flow characteristics after thinning of Japanese cypress forest in a headwater catchment

We evaluated the effects of forest thinning on peak flow and recession characteristics of storm runoff in headwater catchments at Mie Prefecture, Japan. In catchment M5, 58.3% of stems were removed, whereas catchment M4 remained untreated as a control catchment. Storm precipitation and runoff was monitored from June 2004 to January 2007 for the pre-thinning period (113 events) and from March 2007 to June 2009 for post-thinning (103 events). Based on paired-catchment analysis between M5 and M4, volumes of peak flow did not increase significantly after thinning. Recession constant K increased, while recession time of storm runoff did not differ between pre- and post-thinning periods. Storm hydrograph recession tended to be more gradual (i.e., higher K values) after thinning due to increases in available soil water associated with higher net precipitation and decreased evapotranspiration. The lack of changes in peak flow can be attributed to the minimal soil disturbance during thinning. Our hydrograph analysis in paired catchments indicates that thinning may alter specific internal hydrological pathways, such as subsurface flow and groundwater flow.

Population genetic analyses of susceptibility to increased body weight

IntroductionObesity is a complex condition with multifactorial origin. Assuming that such a state is genetically controlled, the aim of our study was to evaluate the degree of genetic homozygosity among overweight and obese individuals by the homozygously recessive characteristics (HRC) test.Material and methodsWe analysed the presence, distribution and individual combination of 15 selected genetically controlled recessive phenotype traits in a sample of 140 individuals with increased body mass index (overweight individuals n = 100 and obese individuals n = 40) and a control group of normal weight individuals (n = 300).ResultsObese individuals have significantly higher mean values for genetic homozygosity than those with normal weight (normal weight: 3.61 ±1.48; obese: 4.13 ±1.47, p < 0.05) and difference in the presence of certain individual combinations of evaluated phenotype traits (Σχ2 = 76.9; p < 0.01). There was no difference in average homozygosity of such genetic markers between groups of normal weight and overweight individuals (normal weight: 3.61 ±1.48; overweight: 3.93 ±1.51, p > 0.05) and between groups of overweight and obese individuals (overweight: 3.93 ±1.51; obese: 4.13 ±1.47, p > 0.05). There is no difference in the presence of certain individual combinations of evaluated phenotype traits between overweight and obese individuals (Σχ2 = 20.6; p > 0.05).ConclusionsThere is a populational genetic difference in the degree of genetic homozygosity and variability between the group of normal weight and group of obese individuals, indicating a possible genetic component. Overweight and obese individuals have a genetic predisposition, but different expression of genetic loads could be one of the possible explanations for different susceptibility to increase of fat mass and body mass index.

The Use of the Recession Index as Indicator for Components of Flow

Hydrograph recession analysis is widely used in hydrological research and water resources planning and management. The most common application is the forecasting of low flows, estimating groundwater resources in a catchment, rainfall runoff models and hydrograph analysis. In the rainfall runoff modelling, some authors have included the recession characteristics in their model. They used the recession parameter for hydrograph separation and modelling surface runoff.This paper presents an alternative commonly used techniques for hydrograph recession analysis, namely of an individual recession segment, the master recession and a relatively recent approach based on wavelet transform was carried out in order to separate analytically the linear component hydrographs by recession index K that is commonly used as an indicator of flow. These methods were applied to a set of measures hydrometric the North-eastern Algeria in the watershed Seybouse. The results show that all the methods tested produce reasonable and comparable results.

Understanding the dynamics of high and low spring flow: a key to managing the water resources in a small urbanized hillslope of Lesser Himalaya, India

Water scarcity is becoming a major problem in High Mountain Basins of Indian Himalaya. Access to fresh water becomes a core concern for every dweller in the summer season all across the Indian Himalayan Region. This paper presents an assessment of two low yielding perennial springs in one of the urban center located in the very steep mountain slopes of Lesser Himalaya. Spring hydrographs were analyzed to investigate the variability and availability of spring flow in three seasons. Dynamic spring flow volume in storage and time at which the flow may cease were also assessed, as they play a crucial role for planning short-term measures. The linear model using the exponential decay equation is found to be sufficiently accurate to model the recession characteristics of spring outflow from the hardrock aquifers for winter season, as the main contribution comes from baseflow with delayed interflow, which is slow diffuse flow in nature. The present study examines the findings from 1 year of spring outflow and rainfall when deficient monsoonal rainfall (moderate drought) is recorded in major parts of the country. The data can play a significant role in estimating dependable minimum water availability from the spring outflow and planning for appropriate capacity of low to medium storage structure for conserving the excess water which goes unutilized even during the high scarcity period. The analysis of duration curve suggests, more focus should be given for conserving the surplus water available during the monsoon through appropriate storage structures, which can be used during the leanest month.

Are Recoveries from Banking and Financial Crises really so Different?

This paper studies the behavior of recoveries from recessions across 59 advanced and emerging market economies over the past 40 years. Focusing specifically on the performance of output after the recession trough, we find little or no difference in the pace of output growth across types of recessions. In particular, banking and financial crisis do not affect the strength of the economic rebound, although these recessions are more severe, implying a sizable output loss. However, recovery does change with some characteristics of recession. Recoveries tend to be faster following deeper recessions, especially in emerging markets, and tend to be slower following long recessions. Most recessions are associated with a slowing, if not outright decline in house prices, but recessions with large declines in house prices also tend to have slower recoveries. Long recessions and those associated with poor housing-market outcomes can lead to sustained output losses relative to pre-crisis trends. Consistent with microeconomic studies showing permanent income loss to job-losing workers during recessions, we find that the sustained deviation in output from trend is associated with a reduction in labor input, especially linked to declines in employment and labor-force participation following recessions. On net, our results imply that the output/employment gap following a severe, long recessions is considerably smaller than is typically assumed by standard macro models, which in turn may have substantial implications for macroeconomic policy during recoveries.

Groundwater intrusion into leaky sewer systems

Vast volumes of groundwater are drained by urban sewer systems. This unwanted flow component intrudes into sewer systems through leaky joints or connected house drains. However, unlike urban storm drainage, it has a high seasonal variation corresponding to groundwater storage and long slow recessions similar to baseflow in rivers also fed by shallow groundwater exfiltrating into the surface waters. By applying the nonlinear reservoir algorithm as used for baseflow separation from total flow in a river, groundwater flow is separated from daily measured influents to treatment plants in Lower Saxony and Baden-Württemberg, Germany and in the Terkos Lake watershed near Istanbul, Turkey. While waste water flows vary only moderately within a year, separated intruded groundwater flows show recessions and seasonal variations correlated to baseflow in neighbouring rivers. It is possible to conclude that recession characteristics of treatment plant influents allow quantification and prediction of groundwater intrusion into sewer systems.

Behavior of Carbon-Carbon Composite under Intense Heating

This paper is concerned with modeling of ablation behavior of carbon-carbon composites used in hot spot areas of reentry space and hypersonic vehicles. Of the three modes of ablation (thermal, chemical and mechanical), the chemical (oxidation) is considered to influence the performance of the material. Aerodynamic heat flux need to be computed separately and is the input for this. The thermal field is obtained by 3D finite element method. Nonlinear transient thermal analysis is carried out, as the material properties are dependent on temperatures. Oxidation rates are computed using the analytical relations available in literature. The oxidation is divided into two regimes: reaction rate and diffusion rate controlled. Mainly the surface temperature controls the regime. The oxidation protected materials are considered by using the parameter “activation energy.” The variations of ambient temperature, pressure and oxygen concentration with altitude are taken into consideration. As the recession takes place, newer surfaces are exposed to aerodynamic heating. Numerical examples are presented to show the effects of: heat flux, altitude and oxidation protection on the recession characteristics. Change of regime from reaction to diffusion rate control depends on parameters such as flow velocity and altitude. The latter has significant influence on ablation rate.

Degree of genetic homozygosity and distribution of AB0 blood types among patients with spina bifida occulta and spina bifida aperta

IntroductionAssuming that spina bifida (SB) is a genetically controlled disease, the aim of our study was to evaluate the degree of genetic homozygosity and the distribution of AB0 blood types among patients with SB occulta and SB aperta by the homozygously recessive characteristics (HRC) test.Material and methodsOur study included an analysis of the presence, distribution and individual combination of 15 selected genetically controlled morpho-physiological traits in a sample of 100 patients with SB (SB occulta N = 50 and SB aperta N = 50) and a control group of individuals (N = 100).ResultsWe found a statistically significant difference between the mean values for genetic homozygosity (SB 4.5 ±0.3; control 3.0 ±0.2, p < 0.001) and also differences in the presence of certain individual combinations of such traits. In 12 (80.0%) of the 15 observed characteristics, recessive homozygosity was expressed to a greater degree among the group of SB patients, while for 9 (60.0%) of the traits this level of difference was statistically significant (Σχ 2 = 266.3, p < 0.001). There was no difference in average homozygosity of such genetic markers between groups of SB occulta and SB aperta patients, but the type of individual variation in the two studied groups significantly differed. In the group of patients with SB the frequency of 0 blood group was significantly increased while B blood group was significantly decreased.ConclusionsOur results clearly show that there is a populational genetic difference in the degree of genetic homozygosity and variability between the group of patients with SB and individuals without clinical manifestations, indicating a possible genetic component in the aetiopathogenesis of spina bifida.

No evidence of apomixis in matroclinal progeny from experimental crosses in the genus Fragaria (strawberry) based on RAPDs

Crossing experiments in Fragaria have frequently resulted in some matroclinal progeny. These have been attributed to either accidental selfing and/or pollen contamination, or apomixis. In this study 202 carefully controlled intra and interspecific crosses in Fragaria were made. No progeny were produced from 164 interploid crosses made between diploids, hexaploids and octoploids but 38 intraploid crosses resulted in 904 F1 plants, of which 42 (4.6%) were found to be morphologically matroclinal. All matroclinal progeny subsequently studied by RAPDs were found to be hybrids and not apomicts. The absence of apomixis among matroclinal progeny in this study casts doubt on previous reports of apomixis in Fragaria. Our results showed that the complete morphological similarity of progeny to the seed parent, even in recessive characteristics, cannot therefore be taken as evidence of apomixis, and may rather indicate the heterozygosity of the pollen parent, emphasising the need to use DNA markers for confirmation of apomixis.

Morphogenetic variability during selection of elite water polo players

In this population-genetic study, we compared morphological and genetic variability of a control group of individuals with that of developing and elite water polo players from Serbia, using a test of determination of homozygously recessive characteristics in humans (HRC-test). Comparisons of the frequencies of ABO and Rh blood types were also made for the groups examined. The degree of genetic homozygosity showed not only statistically significant differences in the mean values obtained for the studied samples (control group 5.1 ± 0.2; emerging water polo players 3.5 ± 0.1; elite water polo players 1.9 ± 0.3 HRCs, out of 20 analysed characteristics), but also differences in the type of distribution, as well as the presence of specific combinations of such traits. During identification of swimming talents, the degree of genetic homozygosity showed a significant decrease, from 4.8 ± 0.3 in the group of pre-competitive young boys, to 2.7 ± 0.3 in selected adult team members, to only 1.9 ± 0.3 in elite water polo players. In the group of pre-competitive young individuals, all characteristics tested also had homo-recessive combinations, while in the group of elite water polo players only 8 of 20 traits were expressed as homozygously recessive. In the group of elite water polo players, who were World and European champions as well as Olympic champions, the frequencies of the A and B blood types were low, AB was absent, and the frequency of the O blood type was high at 72.2% (i.e. almost twice the expected percentage).

The Use of Hydrograph Analysis to Evaluate the Groundwater Contribution to Tigris River Flow at Mosul City

The flow regime of the River Tigris has been studied during ten successive years from 1975 - 1984. The annual hydrographs of the river were analyzed to determine the ground water components by considering the general form of the river regime, and the minimum flows during recession. Master recession curve was derived from the river flow records of the studied catchment area by combining the characteristics of various recession records, and used to check the separation of components contributing to the river flow and also indicate the number of aquifers involve in contributing the ground water to the river. Four major aquifers outside the study area and within the Turkish territory appeared from the analysis contributing ground water of about 58% to 75% percent of the total flow during the ten years period. The total volume of water in storage from the beginning of recession was also determined along the ten years and was varying between 1.0 x 109 – 6.0 x 10 9 m3/ year.

Speculative Capital, Financial Crisis and Emerging Epic Recession

This article re-examines the current financial crisis in the wake of the banking panic of 2008 that erupted in September 2008 and the implosion of financial institutions involving Fannie Mae/Freddie Mac, Lehman Brothers, AIG and others associated with the panic. It is argued that the financial crisis entered a second phase or stage with the above implosions, deepening the general credit contraction and propelling in turn the US and global economy toward a new kind of global economic downturn called an ‘epic recession’. Epic recession, it is argued, is a hybrid, unstable condition that shares characteristics of both traditional recessions and classic global depression. In addition to being more resistant to traditional fiscal-monetary control measures, it is characterized by spreading deflation (from asset values to product, commodity and wages), by growing global currency instability, and by the growing synchronization of real economic decline across global economic sectors. The article notes that the current state of the crisis, and the banking panic of 2008, is similar in a number of ways to the period of 1930–1931 in the US rather than to lesser financial instability events since the 1980s. The article critically examines the dominant strategy employed to date by the US Treasury and US Federal Reserve—a liquidity strategy—and argues that such strategy has been, and will continue to be, a total failure despite a commitment by both agencies to now provide $4 trillion to the banking system. The strategy has failed, it is maintained, because the financial crisis is a solvency crisis and not a liquidity crisis. The article traces the failures of the Treasury and Federal Reserve in detail since the onset of the crisis in late summer 2007. It then explains that the root causes of the crisis originate neither in financial deregulation nor in loose central bank monetary policy, both of which are but enablers of the crisis. Rather the true causes reside in the changing institutional nature of finance capital itself in the late 20th century and in the increasing relative shift of capital to speculative forms of investment at the expense of non-speculative capital accumulation. This growing speculative investment shift is reflected in the massive $38 trillion debt run-up in the US in recent decades, in the current accelerating deflationary unwinding of that debt, and in the credit contraction and epic recession of historic dimensions that the speculative debt-unwinding is now provoking. The nature of speculative finance in the early 21st century is then considered, as well as the relationship between speculative finance and epic recession. These investigations are a prelude to subsequent theoretical work, aimed at integrating a deeper understanding of speculative investment and the new finance capital with Marxist crisis theory based on disproportionality analyses.

Effects of subsurface drainage tiles on streamflow in Iowa agricultural watersheds: Exploratory hydrograph analysis

AbstractFlow from artificial subsurface (tile) drainage systems may be contributing to increasing baseflow in Midwestern rivers and increased losses of nitrate‐nitrogen. Standard hydrograph analysis techniques were applied to model simulation output and field monitoring from tile‐drained landscapes to explore how flow from drainage tiles affects stream baseflow and streamflow recession characteristics. DRAINMOD was used to simulate hydrologic response from drained (24 m tile spacing) and undrained agricultural systems. Hydrograph analysis was conducted using programs PART and RECESS. Field monitoring data were obtained from several monitoring sites in Iowa typical of heavily drained and less‐drained regions. Results indicate that flow from tile drainage primarily affects the baseflow portion of a hydrograph, increasing annual baseflow in streams with seasonal increases primarily occurring in the late spring and early summer months. Master recession curves from tile‐drained watersheds appear to be more linear than less‐tiled watersheds although comparative results of the recession index k were inconsistent. Considering the magnitude of non‐point source pollutant loads coming from tile‐drained landscapes, it is critical that more in‐depth research and analysis be done to assess the effects of tile drainage on watershed hydrology if water quality solutions are to be properly evaluated. Copyright © 2008 John Wiley &amp; Sons, Ltd.

Salinograph trends as indicators of the recession characteristics of stream components

AbstractCompared to hydrograph recession analysis, which is widely applied in engineering hydrology, the quantitative assessment of stream salinity with time (i.e. the salinograph) has received significantly less attention. In particular, while in many previous hydrological studies an inverse relationship between hydrograph and salinograph responses is apparent, the concept of salinity accession (the inversely related salinity counterpart to hydrograph recession) has not been introduced nor quantitatively evaluated in previous literature. In this study, we conduct a mathematical analysis of salinograph accession, and determine new quantitative relationships between salinity accession and hydrograph recession parameters. An equation is formulated that reproduces the general trend in salinity accession. A salinity accession parameter kc is then introduced and is shown to be the ratio of direct runoff to total stream flow recession parameters: kr/k. The groundwater recession parameter kg was estimated using a simple and rapid method that uses both salinograph and hydrograph data. Salinity accession type‐curves illustrate that under certain conditions, the relative steepness of individual salinographs is dependent upon the ratio of groundwater salinity to direct runoff salinity: Cg/Cr. The salinity accession algorithms are applied to two contrasting field settings: Scott Creek, South Australia and Sandy Creek, northern Queensland, Australia. It was found that kg &gt; k during periods of obvious stream flow recession, for the events analysed. Salinograph accession behaviour was fairly similar for both sites, despite contrasting environments. Using assumed end‐member salinities for groundwater and direct runoff based upon field observations, the behaviour of kc from the Scott Creek site was approximately reproduced by varying the initial groundwater to runoff flow ratio: Qg0/Qr0, within reasonable parameter ranges. The use of salinograph information when used in addition to standard hydrograph analyses provided useful information on recession characteristics of stream components. Copyright © 2008 John Wiley &amp; Sons, Ltd.

Population genetic analyses of susceptibility to developing alcohol dependence

Acting on the assumption that susceptibility to alcohol dependence is genetically controlled, we have developed a hypothesis that a generally increased homozygosity level, as well as a changed variability in the group of alcoholics, could be a population genetic parameter for predicting this dependence.A morphophysiological test was used to identify the proportion of homozygously recessive characteristics (HRC test), so that the comparison of presence and distribution of the 25 selected homorecessive traits was carried out between the group of 100 cured alcoholics (the A group), and a control group consisting of 100 non-alcoholics (the C group).This population genetic study revealed not only a statistically significant difference in the mean values of genetic homozygosity (A: 9.3 ± 0.2, C: 8.2 ± 0.2), but also the differences in the distribution type, as well as in the variances of presence of certain specific combinations of such traits. In 18 of the 25 observed characteristics, recessive homozygosity was expressed to a greater degree among the group of alcoholics, while for 10 of the traits this level of difference was statistically significant.The fact that the genes controlling such qualitative recessive traits are distributed in different human chromosomes as their visible markers, could indicate that the genetic homozygosity degrees are visibly higher in the sample of alcohol dependents when compared to the group of individuals free from such dependence. Further application of the HRC testing as an easy procedure may have its practical use in identifying the presence of such indicators in young individuals in order to detect a possible future inclination to alcoholism.

The Influence of Pulleys on the Quantitative Characteristics of Medial Rectus Muscle Recessions: The Torque Vector Model

To develop a new pulley-based torque vector mathematical model for medial rectus muscle recessions and compare it based on known clinical characteristics, to the currently accepted nonpulley length-tension model. The following quantitative characteristics of the results of bilateral medial rectus muscle recessions were chosen for study to see whether the new torque vector model or the classic length-tension model would better predict these characteristics: (1) larger bilateral medial rectus muscle recessions produce more effect per millimeter, with the dose-response curve approximating an exponential shape; (2) the exact location of the preplaced medial rectus muscle suture prior to muscle disinsertion in recessions has minimal effect on the postoperative ocular alignment; and (3) medial rectus muscle recessions of more than eight mm are likely to produce an early consecutive exotropia. Based on the documented location of the medial rectus muscle pulley, the change in the torque vector per millimeter of medial rectus muscle recession was calculated and shown to have an exponential shape. For all three of the quantitative characteristics chosen, the torque vector model appears to better predict the results of medial rectus muscle recessions when compared with the length-tension model. Many quantitative characteristics of medial rectus muscle recessions are better explained by the torque vector model, instead of the classical length-tension model, and support the presence, location, and function of the medial rectus muscle pulley. This new understanding of ocular motility mechanics may influence surgical technique and introduce new surgical considerations for correction of ocular motility disorders.

Bolivia: Impact of Shocks and Poverty Policy on Household Welfare

This paper evaluates the short term impacts on poverty of pro-poor expenditure and total social expenditure during the 1998-2002 period of Bolivian economic recession. Observed characteristics of recession are simulated by the combined effects of negative terms of trade shock, reduction in foreign saving flows and low output growth. Evaluation is performed by simulating the impacts of shocks and social expenditures in an environment of low growth: i) on macro aggregates of consumption, income, saving and prices (based on a simple static 1-2-3 model), ii) on household income and consumption levels, and iii) on consumption based poverty indicators. The following were main results from experiments:The terms of trade shock had greater negative impact on household income then reduction in foreign saving flows. In contrast, reduction in foreign saving flows had greater negative impact on household consumption then the terms of trade shock. The head count ratio has been greater from reduction in foreign saving flows then from the terms of trade shock. Poverty gap and poverty intensity has concentrated in rural areas, being greater from reduction in foreign saving flows then from the terms of trade shock.The combined positive effects from observed social expenditure policy and effort in an environment of low output growth, did not compensate the combined negative impacts from the experienced terms of trade shock and reduction in foreign saving flows.These conclusions show that under macroeconomic disequilibrium poverty reduction efforts become policies of poverty containment or safety net programs. Poverty reduction is a long term objective that requires long term commitment for an environment on macroeconomic stability.