bluuebunny/crossref_metadata_2025 huggingface dataset:
Measuring riparian condition: A comparison of assessments by landholders and scientists
Authors: Wilson Andrea , Jansen Amy , Curtis Allan , Robertson Alistar
Published: July 2006

Summary  To a large extent, the condition of riparian areas in Australia is determined by the management actions of private landholders. In this study, we discuss findings from our research in the Goulburn Broken Catchment comparing landholder and scientist assessments of the condition of riparian areas. We interviewed 33 landholders and undertook ecological condition assessments at 38 sites on privately managed river frontages. Using mail survey data that included landholder assessments of riparian condition, we were then able to compare landholder and scientist assessments. Despite substantial effort in this catchment to improve riparian condition, the riparian zones sampled were generally in poor condition. Landholder and scientist assessments of ecological condition showed a significant positive correlation. This indicated broad agreement, despite some substantial differences in assessment of some components of the condition score. Disparities between scientist and landholder assessments were related to the estimation of native ground cover, leaf litter cover and tree canopy continuity within riparian zones. The capacity of this simple assessment tool to differentiate varying levels of riparian zone degradation demonstrates the potential utility of mailed, self‐assessment surveys to inform management programs and decisions about the allocation of resources for restoration efforts.
Motility is involved in Silicibacter sp. TM1040 interaction with dinoflagellates
Authors: Miller Todd R. , Belas Robert
Published: July 2006

Silicibacter sp. TM1040, originally isolated from a culture of the dinoflagellate Pfiesteria piscicida, senses and responds to the dinoflagellate secondary metabolite dimethylsulfoniopropionate (DMSP) by flagella‐mediated chemotaxis behaviour. In this report we show that swimming motility is important for initiating the interaction between the bacterium and dinoflagellate. Following transposon mutagenesis, three mutants defective in wild‐type swimming motility (Mot–) were identified. The defects in motility were found to be in homologues of cckA and ctrA, encoding a two‐component regulatory circuit, and in a novel gene, flaA, likely to function in flagellar export or biogenesis. Mutation of flaA or cckA results in the loss of flagella and non‐motile cells (Fla–), while CtrA– cells possess flagella, but have reduced motility due to increased cell length. All three Mot– mutants were defective in attaching to the dinoflagellate, particularly to regions that colocalized with intracellular organelles. The growth rate of the dinoflagellates was reduced in the presence of the Fla– mutants compared with Fla+ cells. These results indicate that bacterial motility is important for the Silicibacter sp. TM1040–P. piscicida interaction.
AFLPs congruent with morphological differentiation of Asian common minnow Zacco (Pisces: Cyprinidae) in Taiwan
Authors: Ma Gwo‐Chin , Tsao Hsien‐Shao , Lu Hsiao‐Pei , Yu Hon‐Tsen
Published: July 2006

Morphological and amplified fragment length polymorphism (AFLP) analyses were used to examine the evolutionary relationships among Asian common minnows (Zacco spp.) in Taiwan, where four morphotypes were recently reported. Congruent results from the two sets of analyses indicate that the four morphotypes represent four separate morphometric clades with distinct AFLPs. Consequently, we conclude that four species exist in Taiwan and the systematics of Zacco should be revised accordingly. We also discuss conservation implications and offer a key to the four proposed Zacco species.
An ancient African radiation of corvoid birds (Aves: Passeriformes) detected by mitochondrial and nuclear sequence data
Authors: Fuchs Jérôme , Fjeldså Jon , Pasquet Eric
Published: July 2006

The Malaconotidae, Platysteiridae and Vangidae represent an African and Malagasy assemblage of closely related corvoid taxa with distinctive morphology. Their relationships with their putative Asian closest relatives, and thus their biogeographic history, have not hitherto been thoroughly evaluated. We present evidence that the African and Malagasy groups originated through a single African colonization event c. 37.7 ± 4.6 Myr BP. Three main groups that differ in their foraging behaviour diverged c. 35.8 ± 4.5 Myr BP, suggesting that an African radiation occurred around that time. Several disperal events out of Africa to Madagascar (Vangidae) and Indo‐Malaya (Philentoma, Hemipus and Tephrodornis) took place about 28.9 ± 4.0 Myr BP (Oligocene), a period when faunistic exchanges between Eurasia and Africa seem to have been common. Our estimation of the colonization of Madagascar by the Vangidae is 28.9 ± 4.0 Myr BP, in congruence with the estimated colonization of Madagascar by several African vertebrate groups (carnivorous mammals, snakes, sylvioid passerines, treefrogs, turtles).
Tests and Confidence Intervals for an Extended Variance Component Using the Modified Likelihood Ratio Statistic
Authors: CHRISTENSEN OLE F. , FRYDENBERG MORTEN , JENSEN JENS L. , PEDERSEN JØRGEN G.
Published: July 2006

Abstract. The large deviation modified likelihood ratio statistic is studied for testing a variance component equal to a specified value. Formulas are presented in the general balanced case, whereas in the unbalanced case only the one‐way random effects model is studied. Simulation studies are presented, showing that the normal approximation to the large deviation modified likelihood ratio statistic gives confidence intervals for variance components with coverage probabilities very close to the nominal confidence coefficient.
On the Theory of Optimal Regional Development Based on an Exhaustible Resource
Authors: HOWE CHARLES W.
Published: July 2006

Extensive literatures exist on both regional development and the optimum use of nonrenewable resources over time, but the two have not been melded to consider the effect of combining the optimization of resource exploitation with optimization of population growth and infrastructure investment. A model incorporating these dimensions of regional growth is analyzed using control theory to characterize the optimal time paths of the source‐related investment, resource use, and infrastructure investment. An example of nonrenewable groundwater use in the Colorado High Plains region is analyzed to show the shortcomings of existing regulatory schemes.
Considerations in Extending Shift‐Share Analysis: Note
Authors: HAYNES KINGSLEY E. , MACHUNDA ZACHARY B.
Published: July 2006

One of the limitations to the widespread use of the Esteban‐Marquillas shift‐share extension has been the Stokes (1974) proof of the lack of regional additivity of the Esteban‐Marquillas competitive components. Since the Arcelus extension (1984) of the traditional shift‐share decomposition is a continuation of the logical framework by Esteban‐Marquillas (1972), the Stokes criticism would at first appear to have equal relevance to this new work. This note demonstrates that the relationship between the rate of growth of the larger region and the rates of growth of its constituent subregions is ignored in the Stokes criticism and in the subsequent critique by Beaudry and Martin (1979). By explicitly incorporating the relationship between the rate of growth of the larger region and the rates of growth of the constituent subregions, we also demonstrate that the recent shift‐share extensions by Esteban‐Marquillas and Arcelus share with the classical shift‐share decomposition the desirable additive properties under regional disaggregation of the data.
Effects of Transfers on Remote Regional Economies: The Transfer Economy in Rural Alaska
Authors: KNAPP GUNNAR , HUSKEY LEE
Published: July 2006

In this paper we examine the effects of transfers on the economies of remote regions. A model which describes the consequences of different types of transfers on settlement patterns is developed. The growth of the transfer economy in rural Alaska and its effect on population and income is reviewed. We find that transfer programs in remote regions may have consequences far broader than their original intent. While the programs may improve the standard of living for regional residents, they may also lead to inefficient settlement patterns, increasing dependence on transfers, and a higher cost of eventual adjustment.
American Fertility and Industrial Restructuring: A Possible Link
Authors: ETTLINGER NANCY
Published: July 2006

Despite the fact that economic and demographic factors conventionally are considered to be integrally related, researchers have overlooked recent changes in the structure of the American economy that may have affected fertility in the United States. This article seeks to raise questions and explores the possibility that recent processes of industrial restructuring have created new employment patterns and socioeconomic conditions which have influenced American fertility positively. Specifically, conditions of underemployment and unemployment, generated by the service and manufacturing sectors, may be conducive to increased fertility.
The Arts and Employment: A Case Study of the Stratford Festival
Authors: MITCHELL CLARE J. A. , WALL GEOFFREY
Published: July 2006

This paper examines the impact of the Stratford Festival on employment within the community of Stratford, Ontario. The specific objective is to calculate the number of “secondary” jobs created in Stratford per “primary” job generated at the festival. This is achieved in three stages. First, primary employment is calculated from information provided by theatre personnel. Second, secondary employment is assessed from information collected in a survey of local business proprietors. Third, a festival‐employment multiplier is derived. This reveals the number of secondary jobs created in the community per job at the festival. Results indicate that 1.6 jobs result in Stratford for every job generated at the theatre. This finding provides evidence that cultural organizations contribute positively to the economic climate of a community. The economic consequences of cultural events constitute an important argument for their continued support.
Poverty and Income Transfer Policy at the State Level
Authors: PLOTNICK ROBERT D.
Published: July 2006

This note presents a method for developing data on poverty at the state level and applies it to produce estimates of state poverty for the mid‐1980s. The findings are based on four alternative measures of poverty: the official one, pretransfer poverty, prewelfare poverty and pre‐state‐transfer poverty, a new measure especially useful for analyzing the impact of state transfer policies on poverty. The data are reported and then used to compare the antipoverty impact of states’income support policies.
Business Survival in Rural America: A Three‐State Study
Authors: BUSS TERRY F. , LIN XIANNUAN
Published: July 2006

Many economists expect that new business survival rates in rural areas ought to be low because of inherent disadvantages of rural economies (e.g. small markets). What little evidence there is in support of this expectation is based on data which is biased toward rural areas. Using unemployment insurance tax records (ES202) for Arkansas, Maine, and North Dakota, the authors calculate and analyze new firm survival rates. Results show that new business survival rates are as high in rural areas as they are in urban areas. Further, survival rates in different industrial sectors are comparable, even when level of urbanization is taken into account. The authors conclude that economists may be overstating the inviability of rural in relation to urban economies.
State Fiscal Responses to Federal Government Grants
Authors: STOTSKY JANET G.
Published: July 2006

This paper examines the effect of federal government grants on state fiscal decisions. The study presents a disaggregated analysis of state government that allows for the precise measurement of important fiscal effects. State government is modeled as maximizing a social welfare function defined over government expenditures and taxes. The positive theory of grant response is tested and confirmed. The results indicate that matching grants stimulate government expenditures more than nonmatching grants. The results also suggest that federal grant cutbacks will lead to reductions in state expenditures for all key programs but that the composition of this change will depend on the nature of the federal cutbacks.
Interregional Trade in Producer Services: Review and Synthesis
Authors: HARRINGTON JAMES W. , MACPHERSON ALAN D. , LOMBARD JOHN R.
Published: July 2006

This paper reviews some of the past decade's studies of producer or intermediate‐services exports from local regions. After a discussion of conceptual and methodological problems and inconsistencies, we present these studies according to the three basic methodologies: surveys, location quotients, and input‐output. Overall, our sense is that these studies support limited but important conclusions: (1) If intermediate services are defined broadly, certain of these activities have as their major function interregional or international transfer or trade. By nature, these distributive services have widespread clients, and benefit from locations with substantial physical and communications infrastructure. (2) Among most business‐and financial‐service activities, most offices are established to serve a local region, but may derive some revenues from beyond this expected zone. (3) The exceptions—the activities and establishments that derive much of their revenue beyond such “normal” zones—are particularly specialized, particularly large, or parts of multiregional enterprises. (4) Such firms tend to locate in larger or more specialized urban places, probably because of the labor force, the corporate connections, and the rapid dissemination of ideas, contacts, and information within and among the largest metropolitan areas. These conclusions lead to some general policy recommendations.
The Spatial Structure of Large U. S. Law Firms
Authors: WARF BARNEY , WIJE CHAND
Published: July 2006

Large law firms exert a disproportionate influence over the structure and practice of the legal profession. The spatial structure of these corporations, including the distribution of headquarters and branch offices and their interlinkages, is poorly understood. This paper explores the geography of domestic employment among the largest U. S. 500 law firms using linkage analysis. It highlights the concentration of such firms in large cities and the particular importance of New York and Washington, D. C. In the international arena, U. S. law firms are highly influential. The paper examines the spatial distribution of overseas employment by large U. S. law firms and utilizes input‐output analysis to explore the domestic employment impacts of foreign legal services exports.
Regional Impacts of Foreign Trade in China, 1984–1989
Authors: FAN C. CINDY
Published: July 2006

An issue of heated debate in China is whether the current economic reforms would lead to greater regional inequalities. In this paper one aspect of the reforms, the open‐door policy, is put into focus. Specifically, the analysis investigates how the effect of foreign trade on economic development differs across regions, and whether these regional variations have changed from 1984 to 1989. Based upon the expansion method, models that resolve both the spatial and temporal variations of a relationship are constructed and estimated. The results indicate that foreign trade benefits core provinces and major industrial regions more than other parts of China, but that these differences have diminished in 1989. These findings may be interpreted as evidence of some diffusion of growth from more developed to less developed regions. On the other hand, regional linkages and the mechanisms of diffusion are not well understood and they deserve more attention and research.
Interstate Differences in State and Local Revenues
Authors: IZRAELI ODED
Published: July 2006

The focus of this study is the examination of the interstate differences in per capita state and local revenues. On one side free competition among states is supposed to keep the interstate differences in per capita state and local revenues at a minimum level. On the other side, the interstate differences in variables like income and taste of consumers, natural conditions (like climate), state's size (scale effect), and others may explain the existing interstate differences in per capita state and local revenues. The empirical results indicate that we successfully explained over 90 percent of the variance in per capita state and local revenues. Additional empirical results reveal that the federal government distributes money among states in a discriminate fashion based on region and size.
Canada and the International System of Bank Headquarters Cities, 1968–1989
Authors: SEMPLE R. KEITH , RICE MURRAY D.
Published: July 2006

ABSTRACT This paper examines spatial‐temporal trends in the international system of corporate banking centers. It is evident that the largest corporations locate their headquarters in a formal national decision‐making hierarchy and that national and regional nodes within this hierarchy house the headquarters of major banks. Initially these banks link clients internally. However, as domestic corporations evolve into transnationals, banks follow their customers overseas and establish foreign headquarters. The results of the study indicate that, until 1975, American banking corporations and their financial centers dominated global banking. Since then other countries, most notably Japan and Germany, have successfully challenged this hegemony, while others like the United Kingdom and Canada have been in relative decline. The 1980s witnessed a new era of international coordination of the world's largest industrial countries. Canada, for example, opened its doors to international banking, joined the G‐7, and presently is linked to the world's major banking centers.
Dynamics of the U.S. Interstate Migration System, 1975‐1992
Authors: MILLER GLENN H.
Published: July 2006

ABSTRACT. This note is an empirical study that further develops existing analysis by McHugh and Gober published in this journal (1992). The note follows McHugh and Gober by using annual state‐to‐state migration flow data from Internal Revenue Service records and measures of migration efficiency in analyzing the U.S. interstate migration system. It extends the analysis to a longer period, however—1975 to 1992. This note enhances McHugh and Gober's analysis by extending our knowledge of changes in U.S. migration patterns into the 1990s. But it also suggests modifications to some of their conclusions. First, the note concludes that the emergence of a new pattern of population redistribution in the U.S. in the 1980s, as reported by McHugh and Gober, was indeed significant, but that it was transitory. Second, the note's analysis does not support McHugh and Gober's conclusion of a fairly strong inverse relationship between migration effectiveness and economic expansions and contractions.
Nongovernmental Organizations and the Option Value of Donated Land
Authors: CHAMBERS CATHERINE M. , CHAMBERS PAUL E. , WHITEHEAD JOHN C.
Published: July 2006

ABSTRACT Nongovernmental organizations frequently receive donations of land that have unknown characteristics. This paper presents an analytical model of the option to preserve such land. The nongovernmental organizations' option value arises from the option to preserve or sell the land to generate funds for other preservation projects. We show that die preservation option is equivalent to an option that allows the nongovernmental organization to choose between he maximum of the market value of the land and the preservation value of the land. From the resulting closed from solution of the option to preserve, we perform comparative statics showing how the relevant factors (preservation value of the land, the development value of the land, the length of the that the option is available, and the uncertainty surrounding the relative values of preservation and development) influence the value of the preservation option. In addition, to the basic model, we present three model modifications. The first examines the effects of costly preservation and costly nonpreservation. In the second extension, we examine the effects of freeriding modeled by a continuous variable. In the final modification, we relax the assumption of the fixed survey period and show the optimal development date.
Regional Economic Activity and Petroleum Industry Incentive Policies: Utah's Uintah Basin
Authors: DUFFY‐DENO KEVIN T. , ROBISON M. HENRY
Published: July 2006

ABSTRACT Proponents of petroleum industry subsidies often assert that such policies will have positive economic implications for rural communities. This paper examines the economic impacts of such a policy in Utah. Specifically, this paper quantifies the direct and indirect economic and fiscal impacts of a tax credit granted for oil and gas well workovers in Utah's Uintah Basin. The analysis is made possible by an input‐output model constructed specifically for Utah's oil producing economy. The tax credit policy was found to generate a net fiscal loss for the state. However, it does generate employment in the Uintah Basin. The total per job cost to the state of generating an average of one job per year for 5 years through the tax credit policy is $24,056 (1991 dollars). However, if the public expenditure impacts are taken into account, then the cost per job could be as high as $48,423 (1991 dollars). Whether there are other ways to generate the same employment gains at a lower cost was lost in the political debate surrounding this petroleum industry tax credit.
Square Pegs and Round Holes: Can the Economic Paradigm be Used to Value the Wilderness?
Authors: KAHN JAMES R.
Published: July 2006

ABSTRACT This paper examines whether economic valuation methods are capable of meaningfully measuring the value of the wilderness in monetary terms. Although non‐monetary valuation methods are often important in policy making arenas, this paper focuses on monetary methods. Three questions are examined to determine if these economic valuation methods can contribute to the development of wilderness policy. First, are the valuation methods which have been developed by economists capable of expressing in dollar terms the value of all the services which the wilderness supplies? Second, if these valuation methods are not capable of eliciting all the relevant values, are they still useful for public policy purposes? Third, can the valuation methods be modified or can new methods be developed which can measure some of the values which have not been captured by the previously employed methods? The paper reviews existing valuation methods according to these criteria and finds that the ability to value the wilderness is limited by the shortcomings of currently employed techniques. Refinements to existing methods and potential new methods are suggested to further the valuation process.
The Impact of Tourism on Local Government Expenditures
Authors: WONG JOHN D.
Published: July 2006

The aim of this study is to broaden the understanding of the impact of tourism on local government expenditures. Specifically, a regression model is developed to examine the hypothesis that there is a direct relationship between the degree of reliance of the local economy on tourism and local government expenditures. This study indicates that the degree of reliance of a local economy on tourism does have a statistically significant impact on the level of capital outlays, transportation, police protection, fire protection, corrections, parks and recreation, financial administration, and general government administration expenditures. This analysis indicates that the share of tourism in the local economy can influence expenditures on a variety of local government services, thus tourism should not be regarded as a totally costless instrument of economic development.
Neighborhood Exposure to Toxic Releases: Are There Racial Inequities?
Authors: KRIESEL WARREN , CENTNER TERENCE J. , KEELER ANDREW G.
Published: July 2006

This paper explores the use of empirical evidence to determine whether the exposure of minorities to environmental risks constitutes aversive racism. Connections are drawn between definitions of aversive racism and statistical approaches to research into the relationship between race and risk, paying particular attention to the influence of both non‐racial discrimination and industrial location factors. Federal judicial and executive remedies to aversive racism are examined in light of the standards of evidence presented. An empirical study of the connection between race and exposure to toxic releases is then presented for Census block groups in Georgia and Ohio. It was found that the significance of race depends on the breadth of the explanatory model used in the analysis. A model of overall exposure to toxic releases shows that race is significant in a narrow model of discrimination but not in a broader model including industrial location factors. However, a model of targeting of minorities in the recent location of toxics‐emitting facilities fails to show discrimination in any of the regression analyses. These findings support the view that environmental justice concerns cannot be addressed through reform of siting processes; broader remedies involving more stringent protection of exposure to toxic emissions are more likely to be effective.
Productivity Change in Manufacturing Regions: A Multifactor/Shift‐Share Approach
Authors: HAYNES KINGSLEY E. , DINC MUSTAFA
Published: July 2006

ABSTRACT
The traditional shift‐share model measures the combined effects of output growth and productivity change on employment. A region with above average employment growth either has a favorable industry mix or enjoys a competitive advantage over other regions. To separate the effects of output and productivity, the shift‐share model is extended to decompose the effects of changes in output and productivity on employment. This paper modifies the Rigby‐Anderson extension by separating the contribution of labor and capital to productivity growth in the analysis of regional economic performance, and investigates twenty (two‐digit SIC) manufacturing sectors in twelve states (six snowbelt, six sunbelt states) to assess whether observed changes in employment were due to changes in output or to productivity.
Mood Disorders and Epilepsy Surgery: Lightening the Burden in More Ways than One?
Authors: Garcia Paul A.
Published: July 2006

Changes in Depression and Anxiety after Resective Surgery for Epilepsy

Devinsky O, Barr WB, Vickrey BG, Berg AT, Bazil CW, Pacia SV, Langfitt JT, Walczak TS, Sperling MR, Shinnar S, Spencer SS

Neurology 2005;65(11):1744–1749

Objective

To determine changes in depression and anxiety after resective surgery.

Methods

Data from subjects enrolled in a prospective multicenter study of resective epilepsy surgery were reviewed with the Beck Psychiatric Symptoms Scales (Beck depression inventory [BDI] and Beck anxiety inventory [BAI]) and Composite International Diagnostic Interview (CIDI) up to a 24-month period. χ2 analyses were used to correlate proportions.

Results

A total of 358 presurgical BDI and 360 BAI results were reviewed. Moderate and severe levels of depression were reported in 22.1% of patients, and similar levels of anxiety were reported by 24.7%. Postoperative rates of depression and anxiety declined at the 3-, 12-, and 24-month follow-up periods. At the 24-month follow-up, moderate to severe levels of depression symptoms were reported in 17.6% and 14.7% of the patients who continued to have postoperative seizures. Moderate to severe depression and anxiety were found in 8.2% of those who were seizure-free. There was no relationship, prior to surgery, between the presence or absence of depression and anxiety and the laterality or location of the seizure onset. There were no significant relationships between depression or anxiety at 24-month follow-up and the laterality or location of the surgery.

Conclusions

Depression and anxiety in patients with refractory epilepsy significantly improve after epilepsy surgery, especially in those who are seizure-free. Neither the lateralization nor the localization of the seizure focus or surgery was associated with the risk of affective symptoms at baseline or after surgery.
Do Seizures Harm the Brain?
Authors: Bergen Donna C.
Published: July 2006

Cognitive Decline in Severe Intractable Epilepsy

Thompson PJ, Duncan JS

Epilepsia 2005;46(11):1780–1787

Purpose

To explore the relation between seizure-related variables and cognitive change in patients with severe intractable epilepsy.

Methods

A retrospective analysis of data from 136 patients who had undergone a cognitive assessment on two occasions at an interval of ≥10 years. Cognitive measures included tests of memory and executive skills in addition to intelligence quotients (IQ). Details were available regarding seizure type and frequency in the intertest interval.

Results

Cognitive decline was severe and occurred across a wide range of cognitive functions. The frequency of generalized tonic–clonic seizures was the strongest predictor of decline. Complex partial seizure frequency was associated with a decline in memory and executive skills but not in IQ. Seizure-related head injuries and advancing age carried a poor cognitive prognosis, whereas periods of remission were associated with a better cognitive outcome. Early age at onset was not implicated, and duration of epilepsy was a much less potent predictor of cognitive decline than has been reported in cross-sectional studies. No evidence indicated that a higher level of cognitive function protected against cognitive decline.

Conclusions

Our findings, together with those from animal studies and surgically treated patients, suggest that seizures can have a direct adverse effect on cognition and that good seizure control even after years of intractability can have a beneficial impact on cognitive prognosis. This study was based on individuals who merited two cognitive assessments ≥10 years apart and hence is biased in favor of those with the most severe forms of refractory epilepsy and those with decline.
Diffusion-Weighted Imaging: Can it Play a Role in the Evaluation of Patients with Epilepsy?
Authors: Kanner Andres M.
Published: July 2006

Diffusion-Weighted and Perfusion MRI Demonstrates Parenchymal Changes in Complex Partial Status Epilepticus

Szabo K, Poepel A, Pohlmann-Eden B, Hirsch J, Back T, Sedlaczek O, Hennerici M, Gass A

Brain 2005;128(Pt 6):1369–1376

Diffusion-weighted MRI (DWI) and perfusion MRI (PI) have been mainly applied in acute stroke, but may provide information in the peri-ictal phase in epilepsy patients. Both transient reductions of brain water diffusion, namely a low apparent diffusion coefficient (ADC), and signs of hyperperfusion have been reported in experimental and human epilepsy case studies. We studied 10 patients with complex partial status epilepticus (CPSE) with serial MRI, including DWI and PI. All patients showed regional hyperintensity on DWI, and a reduction of the ADC in (i) the hippocampal formation and the pulvinar region of the thalamus (six out of 10 patients), (ii) the pulvinar and cortical regions (two out of 10), (iii) the hippocampal formation only (one out of 10), and (iv) the hippocampal formation, the pulvinar and the cortex (one out of 10). In all patients, a close spatial correlation of focal hyperperfusion with areas of ADC/DWI change was present. In two patients, hyperperfusion was confirmed in additional SPECT (single photon emission computed tomography) studies. All patients received follow-up MRI examinations showing partial or complete resolution of diffusion and perfusion abnormalities depending on the length of the follow-up interval. The clinical course, EEG, and SPECT results all indicate that MRI detected changes related to prolonged epileptic activity. Combined PI and DWI can visualize haemodynamic and tissue changes after CPSE in the hippocampus, thalamus, and affected cortical regions.
Virus-Induced Injury of the Dentate Gyrus: Deconstructing the Gate in the Way of Seizures
Authors: Mazarati Andrey
Published: July 2006

Kappa Opioid Control of Seizures Produced by a Virus in an Animal Model

Solbrig MV, Adrian R, Baratta J, Lauterborn JC, Koob GF

Brain 2006;129(Pt 3):642–654

Epilepsy remains a major medical problem of unknown aetiology. Potentially, viruses can be environmental triggers for development of seizures in genetically vulnerable individuals. An estimated half of encephalitis patients experience seizures and 4% develop status epilepticus. Epilepsy vulnerability has been associated with a dynorphin promoter region polymorphism or low dynorphin expression genotype, in man. In animals, the dynorphin system in the hippocampus is known to regulate excitability. The present study was designed to test the hypothesis that reduced dynorphin expression in the dentate gyrus of hippocampus due to periadolescent virus exposure leads to epileptic responses. Encephalitis produced by the neurotropic Borna disease virus in the rat caused epileptic responses and dynorphin to disappear via dentate granule cell loss, failed neurogenesis and poor survival of new neurons. Kappa opioid (dynorphin) agonists prevented the behavioural and electroencephalographic seizures produced by convulsant compounds, and these effects were associated with an absence of dynorphin from the dentate gyrus granule cell layer and upregulation of enkephalin in CA1 interneurons, thus reproducing a neurochemical marker of epilepsy, namely low dynorphin tone. A key role for kappa opioids in anticonvulsant protection provides a framework for exploration of viral and other insults that increase seizure vulnerability and may provide insights into potential interventions for treatment of epilepsy.
Market Reaction to Changes in the S&P SmallCap 600 Index
Authors: Gowri Shankar S. , Miller James M.
Published: July 2006

Firms added to (deleted from) the S&P 600 index experience a significant price increase (decrease) at announcement. Firms that newly enter (exit) the S&P universe experience a larger price increase (decrease) than firms that move between S&P indexes. Trading volumes are higher after the announcement and institutional ownership increases (decreases) following index additions (deletions). However, the price and volume effects are temporary and are fully reversed within 60 days, in contrast to the permanent effects reported for S&P 500 changes. Our results support the temporary price‐pressure hypothesis and are similar to results reported for Russell 2000 index changes.
IPO Placement Risk and the Number of Co‐Managers
Authors: Davidson Wallace N. , Xie Biao , Xu Weihong
Published: July 2006

Previous studies show that co‐managers mainly affect initial public offering (IPO) aftermarket activities. We investigate the role of co‐managers in IPO pre‐market activities. We argue that co‐managers help reduce IPO placement risk and hypothesize that IPO issuers hire more co‐managers when placement risk is higher. We find the number of co‐managers is positively associated with three proxies for placement risk. IPOs with more price uncertainty and high‐tech IPOs hire more co‐managers, while IPOs in regulated industries hire fewer co‐managers. We also find larger IPOs, recent IPOs, and IPOs with more reputable lead underwriters hire more co‐managers.
Sex Differences in the Relationships Between Electrocardiographic Abnormalities and the Extent of Left Ventricular Hypertrophy by Echocardiography
Authors: Ochi Hikari , Noda Akiko , Miyata Seiko , Skegawa Mayo , Iwase Mitsunori , Koike Yasuo , Ito Rieko , Yamada Hiroshi , Takamatsu Junki , Yokota Mitsuhiro
Published: July 2006

Background: Several criteria have been proposed for the electrocardiographic diagnosis of left ventricular hypertrophy (LVH). However, their diagnostic accuracy is questionable. Furthermore, the diagnostic accuracy of abnormalities in ST‐T patterns for LVH is known to be uncertain, especially in women. We examined the relationship between electrocardiographic abnormalities and the extent of LVH.

Methods: We studied 76 men and 48 women who satisfied electrocardiographic voltage criteria for LVH (RV5 or RV6≥ 2.6 mV, SV1+ RV5 or SV1+ RV6≥ 3.5 mV). They were classified into three groups based on ST‐T pattern: normal, early strain, and strain. We defined echocardiographic evidence of LVH as an LV wall thickness ≥ 12 mm.

Results: LVH was identified by echocardiography in 55.3% of men and in 47.9% of women. In strain and early strain groups, the prevalence of echocardiographic LVH was significantly higher in men than in women (strain group: 100 vs 75%, P < 0.05, early strain group: 81.8 vs 42.1%, P < 0.05), it did not differ significantly between men and women in normal group. In men, QRS voltage values were significantly correlated with echocardiographic indices. In group strain of men, significant good correlations were observed between QRS voltage values and echocardiographic indices. However, in women, there were no significant correlation between QRS voltage values and echocardiographic indices even in strain group.

Conclusions: The combined criteria of both QRS voltage and ST‐T classification could provide a greater accuracy in diagnosing LVH compared to the criteria using QRS voltage alone in men rather than in women.
The Initial (Earliest) Report of Polymorphous Ventricular Tachycardia
Authors: Jani Sonal , Schweitzer Paul
Published: July 2006

In these short historical notes, we describe the early history of polymorphic ventricular tachycardia. Polymorphous ventricular tachycardia was probably first noted in 1918 by Wilson and Robinson. In a publication describing complete heart block and ventriculophasic arrhythmia, they noted a tachyarrhythmia characterized by multiple extrasystoles of different types at a rapid rate. Also, we briefly discuss the earliest recognized torsades de pointes by Dessertenes in 1966 and the first description of catecholaminergic polymorphic ventricular tachycardia, by Reid in 1977.
Torsades de Pointes as a Cause of Sudden Death in a Patient with Aortic Stenosis and Atrial Fibrillation
Authors: Dilaveris Polychronis , Vassilopoulos Charalambos , Tsagga Evaggelia , Vavuranakis Manolis , Stefanadis Christodoulos
Published: July 2006

The occurrence of sudden cardiac death during Holter monitoring in patients with aortic stenosis has been reported previously. In the majority of the reported cases, the cause of death was a malignant ventricular tachyarrhythmia. The presence of a strong association between frequency and complexity of ventricular arrhythmias and sudden death in patients with aortic stenosis has been proposed. We report the case of a 77‐year‐old woman with aortic stenosis and atrial fibrillation who had an episode of torsades de pointes that degenerated into ventricular fibrillation during Holter monitoring. A short–long–short sequence, but not increased ventricular ectopics, precipitated torsades de pointes and sudden death in this case which is strongly indicative of triggered activity as the underlying mechanism of the lethal arrhythmia.
Culture of multiple peroperative biopsies and diagnosis of infected knee arthroplasties
Authors: MIKKELSEN DORTE B. , PEDERSEN CHRISTIAN , HØJBJERG TOVE , SCHØNHEYDER HENRIK C.
Published: July 2006

Prosthetic joint infections remain difficult to diagnose. In 1981, Kamme & Lindberg described a diagnostic procedure with five peroperative biopsies in patients with total hip arthroplasty (Clin Orthop Relat Res 1981;154:201–7). Its usefulness, however, has not been ascertained for other prosthetic joints undergoing surgical revision. Therefore, we undertook a retrospective study of 120 surgical revisions in 118 patients with knee arthropasties where such biopsies had been obtained. Cases were categorized into three groups based on information available prior to revision and peroperative inspection: prosthetic joint infection (n=26), aseptic loosening (n=58), and mechanical problems (n=36). Fifteen sets were positive, 13 had significant growth (i.e. ≥3 biopsies with the same microbe/s), and 2 had insignificant growth (≤2 positive biopsies). Excluding the group with a mechanical problem, the sensitivity for infection was 12/26 (46%), the specificity 58/58 (100%), the positive predictive value 12/12 (100%), and the negative predictive value 58/72 (81%). In the group with infection there was a trend towards less exposure to antibiotics in cases with positive cultures than cases with negative cultures. The Kamme & Lindberg procedure is applicable also to knee arthroplasties, but the low sensitivity and negative predictive value underline the need for new diagnostic methods.
Genetic alterations of the KLF6 gene in colorectal cancers
Authors: CHO YONG GU , CHOI BYUNG JUN , KIM CHANG JAE , SONG JAE WHIE , KIM SU YOUNG , NAM SUK WOO , LEE SUG HYUNG , YOO NAM JIN , LEE JUNG YOUNG , PARK WON SANG
Published: July 2006

To investigate whether the KLF6 gene plays an important role in the development and/or progression of colorectal cancers, we searched for mutations and allelic loss of the KLF6 gene in 123 colorectal adenocarcinomas by performing PCR‐SSCP sequencing. We found five somatic missense mutations: S155N, G163S, G163D, P183L and G195S. Three of them affected the activation domain of KLF6 and four mutations were predicted to disrupt the putative phosphorylation sites. On LOH analysis, 63 cases were heterozygous for at least one marker and 27 cases (42.9%) showed allelic loss at these markers. These data further support that the KLF6 gene may be one of the candidate tumor suppressor genes in colorectal cancers and that genetic alteration of the KLF6 gene might play a role in the development of colorectal carcinomas.
Restraint stress enhances alveolar bone loss in an experimental rat model
Authors: Nakajima K. , Hamada N. , Takahashi Y. , Sasaguri K. , Tsukinoki K. , Umemoto T. , Sato S.
Published: July 2006

Background and Objective:  The purpose of the present study was to examine the effects of restraint stress on periodontal breakdown resulting from Porphyromonas gingivalis‐challenged periodontitis in rats.

Material and Methods:  To examine the influence of restraint stress on periodontal breakdown, rats were orally challenged with the periodontal pathogen P. gingivalis. Twenty male, specific pathogen‐free (SPF) 3‐wk‐old, Sprague‐Dawley rats were divided into four groups: group A (controls), group B (exposed to restraint stress for 12 h/d for 22 d), group C (orally challenged with P. gingivalis), and group D (exposed to restraint stress for 12 h/d for 22 d and orally challenged with P. gingivalis). After 22 d, all animals were killed. The distance from the alveolar bone crest to the cemento–enamel junction was determined, concentrations of adrenocorticotropic hormone were measured as stress markers, and atrophy of the thymus and spleen were assessed. In addition, the furcation area of the maxillary molars was examined histologically, while gingival cytokine gene expression was assessed by mRNA using reverse transcription–polymerase chain reaction (RT–PCR).

Results:  In the restrained group, all stress markers were elevated, and the thymus and spleen were atrophied. Combined restraint stress and oral challenge with P. gingivalis resulted in significantly higher bone loss, and osteoclasts were observed. RT–PCR analysis revealed low cytokine gene expression in the restrained groups.

Conclusion:  These results suggest that the presence of restraint stress significantly enhances the progression of P. gingivalis‐challenged periodontitis in rats.
Identification of a cowpea γ‐thionin with bactericidal activity
Authors: Franco Octávio L. , Murad Andre M. , Leite José R. , Mendes Paulo A. M. , Prates Maura V. , Bloch Carlos
Published: July 2006

Antimicrobial peptides are an abundant group of proteinaceous compounds widely produced in the plant kingdom. Among them, the γ‐thionin family, also known as plant defensins, represents one typical family and comprises low molecular mass cysteine‐rich proteins, usually cationic and distributed in different plant tissues. Here, we report the purification and characterization of a novel γ‐thionin from cowpea seeds (Vigna unguiculata), named Cp‐thionin II, with bactericidal activity against Gram‐positive and Gram‐negative bacteria. Once the primary structure was elucidated, molecular modelling experiments were used to investigate the multimerization and mechanism of action of plant γ‐thionins. Furthermore, Cp‐thionin II was also localized in different tissues in cowpea seedlings during germination in contrasting conditions, to better understand the plant protection processes. The use of plant defensins in the construction of transgenic plants and also in the production of novel drugs with activity against human pathogens is discussed.
Does side matter? Review comparing right versus left‐sided laparoscopic adrenalectomy
Authors: Fok Ka‐Lung , Poon Chi‐Ming , Leung Canice Tak‐Lun , Li Anthony Chi‐Ngai , Chan Angus Chi‐Wai , Leong Heng‐Tat
Published: July 2006

Objective:  There is concern about the limitation in right‐sided tumour due to the more demanding surgical technique. We aimed to compare right versus left laparoscopic adrenalectomy in terms of operative outcome.

Methods:  This is a review of medical records from 1999 to 2003 in a district hospital. Patients’ records were retrieved from the computer system under procedure name of adrenalectomy (ICD code 07.22). Primary outcome measures included complication and mortality. Other outcome measures included operation time, blood loss and length of stay.

Results:  Thirty‐two consecutive cases (left = 18 vs right = 14) of laparoscopic adrenalectomy were performed from 1999 to 2003. The median age of patients was 45 years. Twenty‐four of them were Conn’s Syndrome (left 14 vs right 10). Median size of tumour was 2 cm (range 0.5–5 cm, left = 2 cm vs right = 1.7 cm; P = 0.87; Mann–Whitney U‐test). One left‐sided tumour was complicated with perinephric haematoma requiring needle aspiration. There was no operative mortality in both groups. There was no difference in operation time (median time; left = 127 min vs right = 120 min; P = 0.91). There were two conversions (right = 1 vs left = 1) due to bleeding and unclear anatomy. The majority of them had minimal blood loss with none above 200 mL. All patients resumed full diet and were ambulatory within 2 days after the operation. There was no difference in hospital stay (right 4.5 days vs left 5 days; P = 0.28 Mann–Whitney U‐test). There was no significant difference between the outcomes of left and right‐sided tumour.

Conclusions:  There is no difference in clinical outcomes between left and right laparoscopic adrenalectomy.
Minimally invasive operating suite in the 21st century: Endo‐Lap operating room
Authors: Yau Kwok‐Kay , Chung Chi‐Chiu , Wong James Cheuk‐Hoo , Li Michael Ka‐Wah
Published: July 2006

Although a number of innovative and futuristic operating room (OR) designs have been proposed, the challenge to implement the OR of the future has never been fulfilled. We believe the setting of future OR should be an integration of the entire spectrum of surgical care: from diagnostic to preoperative planning, and from intraoperative navigation to education. Besides overcoming the deficiencies of today’s OR, it should also create a platform that allows easy inclusion of upcoming innovation. The opening of the brand new, innovative operating room in the Pamela Youde Nethersole Eastern Hospital, the Endo‐Lap OR, is considered a benchmark in the territory. As minimally invasive surgery continues to flourish, we believe the concept and vision behind this Endo‐Lap OR will help to shed light on the future development of OR.