bluuebunny/crossref_metadata_2025 huggingface dataset:
Fecal chlorophyll describes the link between primary production and consumption in a terrestrial herbivore
Authors: Christianson David , Creel Scott
Published: June 2009

Spatiotemporal variation in primary productivity is known to have strong and far‐reaching effects on herbivore ecology, but this relationship is often studied indirectly at broad scales, in part due to the difficulty in measuring selection for green biomass by individual animals. In aquatic systems, the concentration of chlorophyll in herbivore feces has been used as a direct measure of the consumption of photosynthetic primary production, but this method has not been applied to terrestrial systems. We measured chlorophyll concentration in feces from elk (Cervus elaphus) experiencing large fluctuations in primary production in the winter to spring transition over three years. We compared temporal trends in fecal chlorophyll with trends in fecal nitrogen, grass chlorophyll, grass digestible nitrogen, and landscape‐level primary productivity (as described by the normalized difference vegetation index or NDVI). We also directly examined the relationship between fecal chlorophyll and NDVI. Temporal trends in fecal chlorophyll were strong and well described by piecewise regression (adjusted coefficient of determination, = 0.881–0.888), showing uniformly low concentrations throughout winter followed by an abrupt, rapid increase beginning on different Julian days (88, 91, or 110) each year. Changes in fecal chlorophyll closely matched the temporal trend in the chlorophyll and digestible nitrogen concentration of forage grasses collected directly from elk feeding sites. Fecal chlorophyll also tracked broad temporal patterns in fecal nitrogen and NDVI, but discrepancies between the indexes may highlight preferences or constraints on selectivity for green biomass in elk. Spatially and temporally matched NDVI and fecal chlorophyll estimates were uncorrelated until NDVI reached approximately half its seasonal range. Combined, these data describe important patterns in selection for nutritious, green biomass in a temperate herbivore that would be difficult to study without data on fecal chlorophyll. Fecal chlorophyll produced novel and precise descriptions of (and detected large interannual differences in) winter length, severity, and the rate of spring green‐up, as they were experienced by a large, grazing herbivore. Measuring fecal chlorophyll provides a noninvasive, inexpensive, and direct approach to describe an important aspect of foraging ecology in terrestrial herbivores and may be particularly powerful for studying climate effects in seasonal environments.
Aphid fecundity and grassland invasion: Invader life history is the key
Authors: Borer Elizabeth T. , Adams Vincent T. , Engler Gareth A. , Adams Autumn L. , Schumann Canan B. , Seabloom Eric W.
Published: June 2009

Loss or gain of pathogens can determine the trajectory of biological invasions, and invasion by novel hosts also can alter pathogen dynamics to facilitate invasion. Recent empirical and theoretical work has implicated infection by barley and cereal yellow dwarf viruses (B/CYDV), a group of generalist pathogens of the Poaceae family (grasses), as a necessary precursor to the invasion of over 9 million hectares of California's perennial grasslands by exotic annual grasses. The mechanism underlying this pathogen‐mediated invasion hypothesis is elevated vector fecundity on exotic annual grasses. While empirical evidence supports this hypothesis, the links between aphid fecundity, host identity, and host resource supply have not been thoroughly assessed. We performed field and laboratory experiments to examine the fecundity and preference responses of three of the most common aphid vectors of B/CYDV, Rhopalosiphum padi (L.), R. maidis (Fitch), and Sitobion avenae (Fab.), to a combination of host life history (annual and perennial), host provenance (native and exotic), and nutrient supply (mineral N and P fertilization), controlling for host phylogenetic lineage. Aphids consistently had higher fecundity on annual grasses than perennials, regardless of host provenance, age, or nutrient fertilization. In addition, aphids preferentially colonized annual hosts when offered a choice among host species. Multigeneration studies have found that nutrient addition affects both host quality and composition in natural communities; our experimental results indicate that the indirect effects of nutrient fertilization in determining host community composition are of more importance than are the direct effects on host quality to aphid population dynamics.

To summarize the applications of our results, we demonstrate that, in contrast to the current focus on the qualitative differences between invaders and natives, the impact of invasive exotic grasses is not due to host provenance, per se, but arises because the annual invaders differ qualitatively from the native species in interactions with shared pathogen vectors. More generally, our work demonstrates the importance of isolating whether the fate and impacts of an invader are, at their root, due to the provenance of the invader, or due to other characteristics that determine its functional uniqueness in the context of the native community.
Assessing threats to species at risk using stage‐structured state–space models: mortality trends in skate populations
Authors: Swain Douglas P. , Jonsen Ian D. , Simon James E. , Myers Ransom A.
Published: June 2009

Population models are needed to assess the threats to species at risk and to evaluate alternative management actions. Data to support modeling is limited for many species at risk, and commonly used approaches generally assume stationary vital rates, a questionable assumption given widespread ecosystem change. We describe a modeling approach that can be applied to time series of length composition data to estimate vital rates and test for changes in these rates. Our approach uses stage‐structured population models fit within a Bayesian state–space model. This approach simultaneously allows for both process and observation uncertainty, and it facilitates incorporating prior information on population dynamics and on the monitoring process. We apply these models to populations of winter skate (Leucoraja ocellata) that have been designated as “endangered” or “threatened.” These models indicate that natural mortality has decreased for juveniles and increased for adults in these populations. The declines observed in these populations had been attributed to unsustainable rates of bycatch in fisheries for other groundfishes; our analyses indicate that increased natural mortality of adults is also an important factor contributing to these declines. Adult natural mortality was positively related to grey seal (Halichoerus grypus) abundance, suggesting the hypothesis that increased adult mortality reflected increased predation by expanding grey seal herds. Population projections indicated that the threatened population would be expected to stabilize at a low level of abundance if all fishery removals were eliminated, but that the endangered population would likely continue to decline even in the absence of fishery removals. We note that time series of size distributions are available for most marine fish populations monitored by research surveys, and we suggest that a similar approach could be used to extract information from these time series in order to estimate mortality rates and changes in these rates.
A TALE OF TWO GLOBAL HEALTH PROGRAMS Smallpox Eradication's Lessons for the Antipolio Campaign in India
Authors: Bhattacharya Sanjoy , Dasgupta Rajib
Published: June 2009

India provided one of the most challenging chapters of the worldwide smallpox eradication program. The campaign was converted from a project in which a handful of officials tried to impose their ideas on a complex health bureaucracy to one in which its components were constantly adapted to the requirements of a variety of social, political, and economic contexts. This change, achieved mainly through the active participation of workers drawn from local communities in the 1970s, proved to be a momentous policy adaptation that contributed to certification of smallpox eradication in 1980. However, this lesson appears to have been largely forgotten by those currently managing the Global Polio Eradication Initiative. We hope to show ways in which contemporary efforts to eliminate polio worldwide might profitably draw on historical information, which can indicate meaningful ways in which institutional adaptability is likely to help counter the political and social challenges being encountered in India.
Impact of groundwater abstraction on physical habitat of brown trout (Salmo trutta) in a small Danish stream
Authors: Olsen M. , Boegh E. , Pedersen S. , Pedersen M. F.
Published: June 2009

The purpose of this study was to assess the impact of groundwater abstraction on stream discharge and physical habitat conditions for brown trout (Salmo trutta) in a small Danish stream. Stream discharge was simulated using a lumped hydrological model (NAM) and a scenario was set up for stream discharge reference conditions. Stream physical habitat conditions (WUA) were simulated for four life stages of trout using a hydraulic habitat model (RHYHABSIM). The impact of groundwater abstraction on WUA for trout was assessed by combined simulations from the NAM model and the RHYHABSIM model.

The model predicted that groundwater abstraction reduced median annual discharge by 37% and mean annual 90th percentile discharge by 82%. Summer discharge was relatively most affected by groundwater abstraction and WUA was therefore particularly affected by groundwater abstraction during summer. WUA for adult trout was mainly controlled by suitable water depths (>40 cm) even under conditions without abstraction. On an annual basis WUA for fry and juvenile trout was most affected by abstraction. Future modelling should consider improving simulation of low discharges and preferably not use general hydrological models.
An integrated and physically based nitrogen cycle catchment model
Authors: Hansen J. R. , Refsgaard J. C. , Ernstsen V. , Hansen S. , Styczen M. , Poulsen R. N.
Published: June 2009

This paper presents a modelling approach where the entire land-based hydrological and nitrogen cycle from field to river outlet was included. This approach is based on a combination of a physically based root zone model (DAISY) and a physically based distributed catchment model (MIKE SHE/MIKE11). Large amounts of data available from statistical databases and surface maps were used for determination of land use and management practises to predict leaching within the catchment. The modelling approach included a description of nitrate transformations in the root zone, denitrification in the saturated zone, wetland areas and the river system within the catchment. The modelling approach was applied for the Odense Fjord catchment which constitutes one of the pilot river basins for implementation of the European Water Framework Directive. The model simulated overall nitrogen fluxes in the river system consistent with the observed values but showed some discrepancies between simulated and observed daily discharge values The results showed significant differences of denitrification capacities between larger areas such as sub-catchments. This approach has great potential for optimal planning of the establishment of wetlands and further land use legislation with respect to high denitrification rates.
Mapping suitability of controlled drainage using spatial information of topography, land use and soil type, and validation using detailed mapping, questionnaire and field survey
Authors: Joel Abraham , Wesström Ingrid , Messing Ingmar
Published: June 2009

Controlled drainage has the potential to moderate the variability in temporal water runoff and to control N leaching. The objective of this study was, firstly, to present a feasibility study to identify land that is suitable for installation of controlled drainage in four counties in the coastal areas of southern Sweden and, secondly, to present a methodology to validate land that has been identified as suitable. In the feasibility study, digital data of land use, slope gradient and soil types were individually rated and combined into suitability classes. Of 726,000 ha cultivated land, 21% was classified as very highly or highly suitable, 13% moderately suitable and 6% marginally suitable. The validation study comprised analyses of the study areas from (i) digitized information on existing drainage network associations, provided by regional authorities, (ii) a questionnaire study directed to land users and (iii) physical investigation of soil properties of chosen fields on 82 farms. At least 67% of the land being appointed as being suitable for controlled drainage in the feasibility study was drained or had a drainage demand. There was a high correspondence between the results obtained in the validation study as compared to the feasibility study.
Application of flow variability analysis to identify impacts of agricultural land-use change on the River Axe, southwest England
Authors: Climent-Soler D. , Holman I. P. , Archer D. R.
Published: June 2009

Flow variability analysis based on the annual number and duration of pulses above flow thresholds has been used to identify potential impacts of agricultural land-use change on the River Axe catchment (288.5 km2). The analysis shows significant trend and step changes in runoff response which coincide both with changes in land use and management and with changes in rainfall amount and intensity. The effects of climatic variability are taken into account by regression analysis; residuals from regression continue to show a trend which is ascribed to land-use change. Seasonal analysis indicates that the winter season has the greatest change in runoff response but little change in rainfall. In contrast, the summer season shows little change in runoff response but altered rainfall frequency. The success of flow variability methods in identifying trends and the sources of trends in the runoff response on the Axe catchment indicates the potential of the methods for more general application for the development of flood risk management policies based on land-use and management.
Assessment of irrigation dam using real options and discounted cash flow approaches: a case study in Greece
Authors: Michailidis Anastasios , Mattas Konstadinos , Karamouzis Diamantis
Published: June 2009

This article extends the evaluation techniques of an irrigation dam in northern Greece, called “Petrenia”, by comparing the real options approach along with, a traditional one, the discount cash flow. By introducing first a Monte Carlo simulation, the various uncertainty factors can be simulated and alternative value options can be computed, feeding them later in the real options model. Results from the case study in Greece clearly demonstrate that the irrigation dam can be classified as a profitable investment, by applying traditional discount cash flow analysis, while by applying the real options approach the project cannot be classified as profitable. Taking into consideration the uncertainty factors, the real options approach reveals that the investment could be postponed and decision makers can keep the option of investing open. Sequentially, discount cash flow analysis accompanied by the real options approach facilitates decision making and improves the investment assessment analysis. In this particular project assessment, two uncertainty factors, variation in dam capacity and water price, restrict the profitability of the irrigation dam, according to the results of the real options approach.
The Gaza Strip: politics and environment
Authors: Shomar Basem
Published: June 2009

In a region where politics is part of the vocabulary of daily life, this study reveals the environment as a victim of politics in the Gaza Strip. The environmental crisis in Gaza continues to worsen as the groundwater becomes increasingly polluted and the political situation delays hope of “resting” the Gaza aquifer and finding solutions for proper disposal of sewage and solid waste. Wastewater treatment plants (WWTPs) have been destroyed more than once as a result of the turbulent political situation. The Beit Lahia wastewater treatment plant flooded and killed several people in addition to causing casualties and displacing thousands of people, besides destroying homes and killing animals. The closure of the Gaza Strip led to a total paralysis of the economic sector. People's diets were seriously affected. The effects on the industrial sector were not limited only to economic dimensions but affected the environment as well. In mid-2007 alone, more than 70% of the industrial sector was closed and the environmental indicators showed around a 70% decrease in the industrial waste production compared to the previous six years. However, the pollution load was increasing due to the absence of technologies and wastewater treatment facilities. Despite all the complicated circumstances in the Gaza Strip, the population growth rate is the highest in the world which means more needs, further depletion of natural resources, and more waste and pollution.
The reform of public water utilities: successful utility reform efforts as punctuated equilibria
Authors: Schwartz Klaas
Published: June 2009

The reform of public water utilities has received increasing attention over the past decade. In this paper, the reform paths of five public water utilities from five different developing countries are compared. This paper finds that for each case, an external event or crisis brought the issue of water services high on to the political agenda, leading to a window of opportunity in which relatively radical reforms could be implemented.

However, as political support for continued reforms withered, performance improvements became difficult to sustain. Without continued political support, performance improvements can be followed by a relapse to poor performance.
Strongly representable atom structures of cylindric algebras
Authors: Hirsch Robin , Hodkinson Ian
Published: June 2009

A cylindric algebra atom structure is said to be strongly representable if all atomic cylindric algebras with that atom structure are representable. This is equivalent to saying that the full complex algebra of the atom structure is a representable cylindric algebra. We show that for any finite n ≥ 3, the class of all strongly representable n-dimensional cylindric algebra atom structures is not closed under ultraproducts and is therefore not elementary.

Our proof is based on the following construction. From an arbitrary undirected, loop-free graph Γ, we construct an n-dimensional atom structure , and prove, for infinite Γ, that is a strongly representable cylindric algebra atom structure if and only if the chromatic number of Γ is infinite. A construction of Erdős shows that there are graphs Γk(k < ω) with infinite chromatic number, but having a non-principal ultraproduct ΠDΓk whose chromatic number is just two. It follows that is strongly representable (each k < ω) but is not.
Cohomology of groups in o-minimal structures: acyclicity of the infinitesimal subgroup
Authors: Berarducci Alessandro
Published: June 2009

By recent work on some conjectures of Pillay, each definably compact group in a saturated o-minimal structure is an extension of a compact Lie group by a torsion free normal divisible subgroup, called its infinitesimal subgroup. We show that the infinitesimal subgroup is cohomologically acyclic. This implies that the functorial correspondence between definably compact groups and Lie groups preserves the cohomology.
The complexity of learning SUBSEQ(A)
Authors: Fenner Stephen , Gasarch William , Postow Brian
Published: June 2009

Higman essentially showed that ifA is anylanguage then SUBSEQ(A) is regular, where SUBSEQ(A) is the language of all subsequences of strings inA. Lets1,s2,s3,… be the standard lexico-graphic enumeration of all strings over some finite alphabet. We consider the following inductive inference problem:A(s1),A(s2),A(s3),…, learn, in the limit, a DFA for SUBSEQ(A). We consider this model of learning and the variants of it that are usually studied in Inductive Inference: anomalies, mind-changes, teams, and combinations thereof.

This paper is a significant revision and expansion of an earlier conference version [10].
Combined Maximality Principles up to large cardinals
Authors: Fuchs Gunter
Published: June 2009

The motivation for this paper is the following: In [4] I showed that it is inconsistent with ZFC that the Maximality Principle for directed closed forcings holds at unboundedly many regular cardinals κ (even only allowing κ itself as a parameter in the Maximality Principle for <κ-closed forcings each time). So the question is whether it is consistent to have this principle at unboundedly many regular cardinals or at every regular cardinal below some large cardinal κ (instead of ∞), and if so, how strong it is. It turns out that it is consistent in many cases, but the consistency strength is quite high.
Intrinsic bounds on complexity and definability at limit levels
Authors: Chisholm John , Fokina Ekaterina B. , Goncharov Sergey S. , Harizanov Valentina S. , Knight Julia F. , Quinn Sara
Published: June 2009

We show that for every computable limit ordinal α, there is a computable structure that is categorical, but not relatively categorical (equivalently, it does not have a formally Scott family). We also show that for every computable limit ordinal α, there is a computable structure with an additional relation R that is intrinsically on , but not relatively intrinsically on (equivalently, it is not definable by a computable Σα formula with finitely many parameters). Earlier results in [7], [10], and [8] establish the same facts for computable successor ordinals α.
Countable Fréchet Boolean groups: An independence result
Authors: Brendle Jörg , Hrušák Michael
Published: June 2009

It is relatively consistent with ZFC that every countable FUfin space of weight ℵ1 is metrizable. This provides a partial answer to a question of G. Gruenhage and P. Szeptycki [GS1].
In Vivo Activation of AMP-Activated Protein Kinase Attenuates Diabetes-Enhanced Degradation of GTP Cyclohydrolase I
Authors: Wang Shuangxi , Xu Jian , Song Ping , Viollet Benoit , Zou Ming-Hui
Published: June 2009

OBJECTIVE

The activation of AMP-activated protein kinase (AMPK) has been reported to improve endothelial function. However, the targets of AMPK in endothelial cells remain poorly defined. The aim of this study was to test whether AMPK suppresses the degradation of GTP-cyclohydrolase (GTPCH I), a key event in vascular endothelial dysfunction in diabetes.

RESEARCH DESIGN AND METHODS

Both human umbilical vein endothelial cells and aortas isolated from streptozotocin-injected diabetic mice were assayed for phospho-AMPK (Thr172), GTPCH I, tetrahydrobiopterin (BH4), and endothelial functions.

RESULTS

Oral administration of metformin (300 mg · kg−1 · day−1, 4 weeks) in streptozotocin-injected mice significantly blunted the diabetes-induced reduction of AMPK phosphorylation at Thr172. Metformin treatment also normalized acetylcholine-induced endothelial relaxation and increased the levels of GTPCH I and BH4. The administration of AICAR, an AMPK activator, or adenoviral overexpression of a constitutively active mutant of AMPK abolished the high-glucose–induced (30 mmol/l) reduction of GTPCH I, biopeterins, and BH4 but had no effect on GTPCH I mRNA. Furthermore, AICAR or overexpression of AMPK inhibited the high-glucose–enhanced 26S proteasome activity. Consistently, inhibition of the proteasome by MG132 abolished high-glucose–induced reduction of GTPCH I in human umbilical vein endothelial cells. Further, aortas isolated from AMPKα2−/− mice, which exhibited elevated 26S proteasome activity, had reduced levels of GTPCH I and BH4. Finally, either administration of MG132 or supplementation of l-sepiapterin normalized the impaired endothelium-dependent relaxation in aortas isolated from AMPKα2−/− mice.

CONCLUSIONS

We conclude that AMPK activation normalizes vascular endothelial function by suppressing 26S proteasome-mediated GTPCH I degradation in diabetes.
Effects of osteoarthritis on radiographic measures of laxity and congruence in hip joints of Labrador Retrievers
Authors: Gold Randi M. , Gregor Thomas P. , Huck Jennifer L. , McKelvie Pamela J. , Smith Gail K.
Published: June 2009

Objective—To determine effects of hip joint osteoarthritis on radiographic measures of hip joint laxity and congruence.

Design—Longitudinal study.

Animals—40 Labrador Retrievers.

Procedures—Dogs were assigned to 2 groups based on radiographic evidence of osteoarthritis. Dogs in the osteoarthritis group were free of osteoarthritis at initial radiographic evaluation (t1) and developed osteoarthritis by a subsequent radiographic evaluation (t2). Dogs in the nonosteoarthritis group had no radiographic osteoarthritis at either evaluation. Hip joint laxity was quantified by use of the distraction index (DI) from a distraction radiographic view and use of the Norberg angle (NA) from a ventrodorsal hip-extended radiographic view. The compression index (CI) from a compression radiographic view was used as a measure of joint congruence (concentricity).

Results—Hip joint laxity (NA or DI) did not change over time in the nonosteoarthritis group. Mean hip joint laxity (NA and DI) for the osteoarthritis group was greater at t1 than for the nonosteoarthritis group. With the onset of osteoarthritis, mean NA decreased significantly and mean CI increased significantly, but mean DI remained unchanged.

Conclusions and Clinical Relevance—No radiographic evidence for compensatory hip joint tightening associated with osteoarthritis was detected. Hip-extended radiography revealed that hip joints got looser with osteoarthritis and NA decreased. Hip joint laxity (DI) on distraction radiographs was unchanged by the onset of osteoarthritis and remained constant in the osteoarthritis and nonosteoarthritis groups at both evaluations. However, the CI increased with osteoarthritis, as reflected in nonzero indices (incongruence). The CI may be a valid marker for early hip joint osteoarthritis.
Clinical, histologic, and immunohistochemical characterization of wart-like lesions on the paw pads of dogs: 24 cases (2000–2007)
Authors: Balara Jason M. , McCarthy Robert J. , Kiupel Matti , Buote Melanie A. , Wise Annabel G. , Maes Roger K.
Published: June 2009

Objective—To determine clinical, histologic, and immunohistochemical findings for dogs with wart-like lesions involving the paw pads.

Design—Retrospective case series.

Animals—24 dogs (18 Greyhounds and 6 dogs of other breeds).

Procedures—Medical records were reviewed for information on signalment, physical examination findings, concurrent disease processes, location of all lesions, and, when available, results of histologic examination of biopsy specimens. Available biopsy specimens (n = 11) were submitted for immunohistochemical staining and a PCR assay to identify viral inclusion bodies.

Results—In Greyhounds, most lesions involved the pads of the third and fourth digits, had a consistent histologic appearance without evidence of inflammation, were negative for papillomavirus, and had an unsatisfactory response to treatment. In other breeds, lesions often involved the pads of non–weight-bearing digits, had histologic evidence of inflammation, were positive for papillomavirus, and responded to surgical treatment.

Conclusions and Clinical Relevance—Results suggested that wart-like lesions involving the paw pads of Greyhounds were a distinct clinical entity with features resembling porokeratosis plantaris discreta in humans. In Greyhounds, these lesions were not associated with an underlying viral etiology and, therefore, should not be considered plantar warts. Alternative treatments should be investigated because current treatments were generally unsuccessful in Greyhounds. Wart-like lesions of the paw pads in other breeds were often associated with papillomavirus, and surgical excision appeared curative.
Major abdominal evisceration injuries in dogs and cats: 12 cases (1998–2008)
Authors: Gower Sara B. , Weisse Chick W. , Brown Dorothy C.
Published: June 2009

Objective—To describe the clinical characteristics, treatment, complications, and outcome of dogs and cats treated surgically for major abdominal evisceration.

Design—Retrospective case series.

Animals—8 dogs and 4 cats.

Procedures—Medical records from January 1998 through March 2008 were reviewed to identify animals that underwent surgery for major abdominal evisceration. Data regarding cause of evisceration, signalment, physiologic variables, and hematologic variables were collected. Details of treatment, duration of hospitalization, and outcome were recorded. Linear regression analysis was performed to evaluate the association of signalment, physiologic variables, and hematologic variables on the number of days of hospitalization.

Results—Major abdominal evisceration was secondary to a traumatic event in 4 animals and to postsurgical dehiscence in 8 animals. All animals had evisceration of the intestines and gross contamination with dirt, leaves, or litter. Two animals eviscerated the spleen, and 1 animal had a perforated colon and was leaking feces into the peritoneal cavity. All animals underwent exploratory abdominal surgery. Surgical procedures performed included resection of compromised intestine, body wall repair, diaphragmatic hernia repair, nephrectomy, splenectomy, and primary colonic repair. All animals survived to discharge from the hospital. Median duration of hospitalization was 4 days (range, 1 to 7 days). Factors associated with an increase in duration of hospitalization included evisceration secondary to trauma, high lactate concentration at time of admission, and small body size.

Conclusions and Clinical Relevance—Despite the dramatic appearance of major abdominal evisceration in cats and dogs, prompt and aggressive medical and surgical intervention can provide a favorable outcome.
Motivations for Web-Based Scholarly Publishing: Do Scientists Recognize Open Availability as an Advantage?
Authors: PARK JI-HONG
Published: June 2009

The open availability of journal articles is expected to encourage scholars to publish in Web-based publishing venues, as it may provide more visible and wider dissemination of their research. Some studies, however, report no evidence of such relative advantages, although an advantage may be conferred by other factors. Despite emerging disputes about the effects of open availability, scholars' perceptions of the phenomenon are not well understood. Do they recognize the advantages of open availability? Or do they consider other factors more important? This study sought to answer these questions by examining reasons why scholars publish in open-access venues and the extent of their motivations. To accomplish this goal, results were tallied from a Web-based survey of 1104 scientists around the world. The data analysis identified eleven relevant motivational factors: six attitudinal factors, two perceived control factors, and one demographic factor. Together, these factors significantly influenced the intention to adopt open-access publishing. Factors related to social influence and perceived topical compatibility appeared to be insignificant. The influence of attitudinal and perceived control factors, however, varied based on tenure status. The biggest difference between tenured and untenured groups was the rank of perceived visible advantages, implying that open availability has different levels of significance depending on tenure status.
Writing a Series of Best-Selling Research Reference Books
Authors: CHUA YAN PIAW
Published: June 2009

This author conducted a needs assessment before embarking on the journey of writing a research reference book. The study was carried out to, among other things, identify the topics that the book should cover and determine what readers (561 lecturers at a teacher training institute) would consider a fair asking price for it. Based on the results of this needs assessment, the author wrote a series of books titled Research Method and Statistics, consisting of five volumes totalling fifty-eight chapters and 1677 pages. This five-volume set was published by McGraw-Hill Education Malaysia between 2006 and 2008. Since its publication, the series has been widely used by researchers, educators, and students in local higher educational institutions and is one of McGraw-Hill's best-selling series. This article describes the needs assessment and details how the results were used as the basis for writing a successful book.
Increase in diameters of vasospastic intracranial arteries by intraarterial papaverine administration
Authors: Milburn James M. , Moran Christopher J. , Cross DeWitte T. , Diringer Michael N. , Pilgram Thomas K. , Dacey Ralph G.
Published: June 2009

Object. This study was conducted to determine if there is a change in intracranial arterial diameters after papaverine infusion for vasospasm and to determine whether the change occurs in proximal, intermediate, and distal arteries.

Methods. The authors measured arterial diameters retrospectively in all patients who received intraarterial papaverine for treatment of vasospasm between November 1992 and August 1995. Patients who received papaverine in the same session with or following angioplasty were excluded. Measurements were made in a blinded manner with the aid of a magnification loupe at 12 predetermined sites on each angiogram before and after papaverine infusion. Eighty-one treatments in 34 patients were included. Angiograms obtained at the time of presentation with subarachnoid hemorrhage (SAH) were examined in 26 of the 34 patients. Nine carotid territories visualized by repeated angiography on the day after infusion were examined to determine the duration of the papaverine effect.

Conclusions. In all treatment groups an increase was found in the average arterial diameters ranging from 2.8 to 73.9%, with a mean increase of 26.5%. Increases in diameter were observed in proximal, intermediate, and distal arteries. The timing of treatments ranged from Day 3 to Day 19 post-SAH, and there was no relationship between timing and arterial responsiveness (r = −0.06). There was a moderately good correlation between the degree of vasospasm in an artery and its responsiveness to papaverine (r = −0.54, −0.66, and −0.66, for proximal, intermediate, and distal arteries, respectively). The effect of papaverine did not persist until the following day in patients in whom repeated angiography was performed.
Formation of intracerebral cavernous malformations after brain radiation treatment for central nervous system neoplasia in children
Authors: Larson Jeffrey J. , Ball William S. , Bove Kevin E. , Crone Kerry R. , Tew John M.
Published: June 2009

Object. Radiation is a common treatment modality for pediatric brain tumors. The authors present a retrospective review of six children who developed cerebral cavernous malformations after they underwent radiation treatment for central nervous system (CNS) neoplasia and propose two possible models to explain the formation of cavernous malformations.

Methods. Three boys, aged 13, 9, and 17 years, suffered intracerebral hemorrhages from cerebral cavernous malformations 87, 94, and 120 months, respectively, after they received whole-brain radiation therapy (WBRT) for acute lymphocytic leukemia. A 10-year-old girl and a 19-year-old man developed temporal lobe cavernous malformations 46 and 48 months, respectively, after they received radiation therapy for posterior fossa astrocytomas. A 12-year-old girl developed a temporal lobe cavernous malformation 45 months after WBRT was administered for a medulloblastoma. In all of these cases the cavernous malformation appeared in the irradiated field, was not known to be present prior to radiation therapy, and developed after a latency period following treatment. The incidence of cavernous malformations in these patients suggests that children who undergo radiation therapy of the brain may have an increased risk of hemorrhage.

Conclusions. Two possible models may explain the formation of cavernous malformations following brain radiation in these patients. First, the cavernous malformations may form de novo in response to the radiation. Second, the cavernous malformations may have been present, but radiographically occult, at the time of radiation therapy and may have hemorrhaged in response to the radiation. The authors conclude that cavernous malformations may develop after brain radiation and propose a possible mechanism for this formation.
Cell type—specific development of rodent central nervous system progenitor cells in culture
Authors: Meltzer Hal , Hatton James D. , U Hoi Sang
Published: June 2009

Object. The aim of the study was to assess the pluripotential central nervous system (CNS) progenitor cells that give rise to the many differentiated neuronal and glial cell types of the adult mammalian brain and the role of peptide growth factors such as the epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). The action of these factors is crucial to the survival and ultimate differentiation of these CNS progenitor cells. However, the precise role of EGF and bFGF in the time course of cellular development, the acquisition of cell type specificity, and possible differential mitogenic behavior has not been clearly defined.

Methods. The authors defined the time course of CNS progenitor cell development in cultured embryonic rodent cells by using immunocytochemical analysis to identify the expression of pluripotential (nestin)-, neuron (microtubuleassociated protein-2 [MAP-2])-, and glia (glial fibrillary acidic protein [GFAP])-specific proteins in response to treatment with EGF and bFGF alone or in combination. The bromodeoxyuridine (BUdR) labeling index for each treatment group was used to define the mitogenic effects of each growth factor. In this investigation, the authors observed that progenitor cells develop in a stereotypical fashion when exposed to bFGF or EGF. Marked staining for nestin was evident soon after plating. This declined over time as staining for MAP-2 and GFAP increased. When treated with EGF alone, cells maintained their nestin immunoreactivity longer than those treated with bFGF alone or in combination with EGF. Treatment with bFGF alone promoted a significant increase in MAP-2 and, to a much lesser extent, GFAP reactivity. This was observed concomitant with the decline in nestin staining. The BUdR labeling index was similar among the different treatment groups and declined similarly over time in all treatment groups.

Conclusions. The effects of EGF and/or bFGF on the expression of development- and lineage-specific markers likely reflect the specific effects of these factors on developmental processes. These data indicate that bFGF exerts a preferential effect on neuronal development and, to a lesser extent, glial development, which is not explained by selective mitogenicity. The persistence of nestin staining seen in the cells treated with EGF alone indicates that EGF may function as a stem cell survival factor. This study provides evidence that CNS cell type—specific development can be altered by the manipulation of peptide growth factors that act as differentiation agents.
Transparaspinal exposure of dumbbell tumors of the spine
Authors: Onesti Stephen T. , Ashkenazi Ely , Michelsen W. Jost
Published: June 2009

✓ The authors present a surgical technique for resection of dumbbell tumors of the spine. The transparaspinal exposure combines laminectomy and sectioning of the paraspinal muscles through a transverse incision. The procedure allows total tumor resection by means of a single posterior approach in selected patients, thus obviating the need for a combined anteroposterior operation. The advantages and disadvantages of the transparaspinal approach compared with the more extensive lateral extracavitary approach are discussed.
Treatment of high-grade spinal cord astrocytoma of childhood with “8-in-1” chemotherapy and radiotherapy: a pilot study of CCG-945
Authors: Allen Jeffrey C. , Aviner Shraga , Yates Allan J. , Boyett James M. , Cherlow Joel M. , Turski Patrick A. , Epstein Fred , Finlay Jonathan L. , _ _
Published: June 2009

Object. The purpose of this study was to devise an improved method of treating high-grade gliomas of the spinal cord in children who have a dismal prognosis following conventional treatment.

Methods. Eighteen children with newly diagnosed high-grade astrocytomas arising in the spinal cord were enrolled in the Children's Cancer Group (CCG) protocol 945. Following surgery, they were all assigned to receive two cycles of “8-drugs-in-1-day” (8-in-1) chemotherapy prior to radiotherapy and eight additional cycles thereafter. A centralized neuropathology review was used to confirm the diagnosis of high-grade astrocytoma in 13 of the 18 children: anaplastic astrocytoma (eight patients), glioblastoma multiforme (four patients), and mixed malignant glioma (one patient). Diagnoses were discordant in five patients. There were eight boys and five girls in the group with confirmed diagnoses, with a median age of 7 years (range 1–15 years). The extent of resection was confirmed by computerized tomography or magnetic resonance (MR) evaluation in five of 13 patients. There were six gross-total or near-total resections (> 90%), four partial or subtotal resections (10–90%), and three biopsies. Six patients showed evidence of leptomeningeal metastases at diagnosis based on staging MR examinations. Eight of the 13 patients completed at least eight of the prescribed 10 cycles of chemotherapy; five received craniospinal radiotherapy and five spinal radiotherapy.

Conclusions. The 5-year progression-free and total survival rates for the 13 children were 46 ± 14% and 54 ± 14%, respectively. Seven patients suffered a relapse at the primary site, four of whom also had leptomeningeal metastases. Seven of the 13 patients (54%) remain alive at the time of this report at a median of 76 months (range 51–93 months) from study entry. Six patients died between 8 and 38 months after diagnosis, all with active disease. Intensification of therapy may further improve outcome in this high-risk population.
Follow-up results of using microvascular decompression for treatment of glossopharyngeal neuralgia
Authors: Kondo Akinori
Published: June 2009

Glossopharyngeal neuralgia (GPN) is an uncommon disorder that is characterized by a severe lancinating pain commonly induced by swallowing. There has been some debate among various authors as to which surgical procedure should be adopted to treat cases of GPN: microvascular decompression (MVD) or partial rhizotomy. The latter necessitates the partial destruction of normal neural structures.

Object. The purpose of this paper is to present follow-up results in patients with GPN who underwent MVD.

Methods. Between 1980 and 1995, 20 patients underwent MVD for GPN. Results were studied to verify the effectiveness of MVD performed in 16 patients before 1991 who participated in follow-up evaluation for more than 5 years postoperatively. The follow-up period ranged from 5 to 16 years (mean ± standard deviation 11.6 ± 2.8 years). The method adopted for MVD was to reposition the offending vessel, such as a troublesome vertebral artery or posterior inferior cerebellar artery that is commonly ectatic and arteriosclerotic, by lifting the loop of the artery and using glue to affix it to the nearby dura mater of the petrous bone.

Conclusions. Pain was relieved in all cases. Two patients complained of persistent mild hoarseness, causing the inability to speak loudly, and two patients complained of occasional coughing episodes that occurred for a couple of years after the surgery. No other complications were reported and no recurrence of pain was noted during the follow-up period.

This procedure provided satisfactory results by preserving important perforating arteries in this area and by repositioning offending arteries in a safer and surer fashion, thus reducing complications and recurrence of GPN.
Magnetic resonance imaging findings in ossification of the posterior longitudinal ligament of the cervical spine
Authors: Koyanagi Izumi , Iwasaki Yoshinobu , Hida Kazutoshi , Imamura Hiroyuki , Abe Hiroshi
Published: June 2009

Object. Because of the lack of magnetic resonance (MR) signal from cortical bones, MR imaging is inadequate for diagnosing ossified lesions in the spinal canal. However, MR imaging provides important information on spinal cord morphology and associated soft-tissue abnormality. The purpose of this study is to determine the role of MR imaging in the diagnosis and treatment of patients with ossification of the posterior longitudinal ligament (OPLL) of the cervical spine.

Methods. The authors reviewed MR imaging findings in 42 patients with cervical OPLL who were examined with a superconducting MR imaging system. The types of OPLL reviewed included eight cases of continuous, 21 cases of segmental, and 13 cases of the mixed type. All patients were treated surgically either by anterior (26 cases) or posterior decompression (16 cases).

Conclusions. The T1-weighted images clearly demonstrated the spinal cord deformity caused by OPLL. Associated disc protrusion was found to be present at the maximum compression level in 60% of the patients in this series. The highest incidence of disc protrusion (81%) was found in patients with segmental OPLL. Intramedullary hyperintensity on T2*-weighted imaging was noted in 18 patients (43%). The neurological deficits observed in these 18 patients were significantly more severe than those observed in the other 24 patients. Postoperative MR imaging revealed improvement in the spinal cord deformity, although the intramedullary hyperintensity was still observed in most cases. The present study demonstrates the importance of associated disc protrusion in the development of myelopathy in patients with cervical OPLL. Magnetic resonance imaging findings may be used to help determine the actual levels of spinal cord compression and to suggest the method of surgical treatment.