bluuebunny/crossref_metadata_2025 huggingface dataset:
SUPPLIES OF SOME RAW MATERIALS IN BRITISH AGRICULTURE AND THEIR IMPLICATION'S ON SOIL FERTILITY
Authors: BARKER A. S.
Published: August 2010

Before the war, livestock production was responsible for the major part of the removals of N, P, K nutrients from British farms, but during the war (temporary ?) precedence in this respect was taken by direct human food crops. In both periods the feeding of home–grown crops to livestock was probably responsible for an annual rate of nutrient losses exceeding those due to removals from farms in crops and stock products combined.

In addition to larger fertilizer inputs required for the expanded area of direct human food crops during the war, similar increases were essential for the attempt to sustain the pre–war cattle output, even with substantial reductions in the numbers of all other livestock. Nutrient materials for these purposes were not available during the war in quantity sufficient to allow. phosphate and potash applications to grassland in any appreciable degree; permanent grass, therefore, was the most likely to deteriorate in “fertility,” i.e. in potential productivity.

So long as relatively unlimited supplies of imported feeding–stuffs are available at prices permitting their profitable processing into livestock products, they may largely compensate for the N, P, K losses incurred in the analogous conversion of home–grown crops and the nutritive quality of the latter fodders is not necessarily a consideration of prime importance. The war has demonstrated that British farming has still a long way to go before it approaches a self–sufficient livestock economy on the pre–war scale and should that be desirable in the future, it implies the production of foods of higher nutritive values.

A post–war expansion of U.K. cattle and sheep production will demand the utmost economic exploitation of grass since it provides the cheapest mode of feeding. That implies a general improvement in past standards of management to secure from grass the maximum contribution to the total nutritive requirements of the stock, which in turn will, depend on increased throughputs of the major soil nutrients more commensurate with removals than has been the common practice.
Decline of a Tropical Montane Amphibian Fauna
Authors: Lips Karen R.
Published: August 2010

On the basis of surveys conducted between 1991 and 1996, I report a decline of the amphibian fauna at Las Tablas, Puntarenas Province, Costa Rica. I propose that the reduction in the abundance of Atelopus chiriquiensis and Hyla calypsa, the presence of dead and dying individuals of six species of frogs and salamanders, and changes in population sex ratios of A. chiriquiensis and H. calypsa are evidence for “atypical” population fluctuations. Species with both aquatic eggs and aquatic larvae were most affected (e.g., Rana vibicaria, Hyla rivularis), whereas species with direct development or those that lack tadpoles, such as rainfrogs ( Eleutherodactylus spp.) and some salamanders (e.g., Bolitoglossa minutula), do not seem to have declined in numbers. In light of this evidence and in comparison with other declines in tropical upland Australia, Brazil, and Costa Rica, I conclude that environmental contamination (biotic pathogens or chemicals) or a combination of factors (environmental contamination plus climate change) may be responsible for declines in the amphibian populations at this protected site.

Una Redución en las Poblaciones de Anfibios en una Localidad Tropical Ubicada en las Montañas

Basado en encuestas dirigidas por un período de 5 años, reporto una disminución de la fauna anura en un sitio elevado de la región sur central de Costa Rica. Yo propongo que la reducción en el número de individuos, los individuos muertos o moribundos y los cambios en la proporción radial de los sexos, demuestran que las fluctuaciones no son típicas o normales. Las especies más afectadas son aquellas que tienen posturas de huevos acuáticos y renacuajos acuáticos, mientras que aquellas con desarrollo directo (sin renacuajos) no parecen haber disminuido en la misma cantidad. Tomando en cuenta estos datos y comparándolos a las disminuciones observadas en otros sitios montañosos del trópico, concluyo que la contaminación del medio ambiente (causado por un microbio patógeno o químico) o quizás causado por una combinación de factores (contaminación del medio ambiente más cambios del clima) puede ser la causa de la disminución de la población anfibia de este sitio protegido.
Species Redundancy and Ecosystem Reliability
Authors: Naeem Shahid
Published: August 2010

The concept of species redundancy in ecosystem processes is troublesome because it appears to contradict the traditional emphasis in ecology on species singularity. When species richness is high, however, ecosystem processes seem clearly insensitive to considerable variation in biodiversity. Some elementary principles from reliability engineering, where engineered redundancy is a valued part of systems design, suggest that we should rethink our stance on species redundancy. For example, a central tenet of reliability engineering is that reliability always increases as redundant components are added to a system, a principle that directly supports redundant species as guarantors of reliable ecosystem functioning. I argue that we should embrace species redundancy and perceive redundancy as a critical feature of ecosystems which must be preserved if ecosystems are to function reliably and provide us with goods and services. My argument is derived from basic principles of reliability engineering which demonstrate that the probability of reliable system performance is closely tied to the level of engineered redundancy in its design. Empirical demonstrations of the value of species redundancy in ecosystem reliability would provide new insights into the ecology of communities and the value of species conservation.

Redundancia de Especies y Confiabilidad del Ecosistema

El concepto de redundancia de especies en procesos ecológicos es problemático puesto que aparentemente contradice el énfasis tradicional en ecologia sobre la singularidad de las especies. Sin embargo, cuando la riqueza de especies es alta, los procesos del ecosistema parecen claramente insensibles a variaciones considerables de la biodiversidad. Principios elementales de confiabilidad en ingenieria, donde la redundancia es evaluada como parte del diseño de sistemas, sugiere que deberíamos repensar nuestra postura sobre la redundancia de especies. Por ejemplo, un principio central de confiabilidad ingenieril es que la confiabilidad siempre incrementa cuando componentes redundantes son agregados al sistema, un sistema que directamente soporta especies redundantes como garante del funcionamiento del ecosistema. Yo argumento que deberíamos abarcar la redundancia de especies y percibir redundancia como una característica crítica del ecosistema que debe ser conservada si los ecosistemas funcionaran confiablemente y nos provean de bienes y servicios. Demostraciones empíricas de el valor de la redundancia de especies en confiabilidad de ecosistemas provee nuevas intuiciones dentro de la ecología de comunidades y el valor de la conservación de las especies.
Population Monitoring of the Coelacanth (Latimeria chalumnae)
Authors: Hissmann Karen , Fricke Hans , Schauer Jürgen
Published: August 2010

In 1991 the population size of the coelacanth (  Latimeria chalumnae) on Grande Comore Island, Western Indian Ocean, was estimated at 230–650 individuals, based on counts of individually recognized fish in an 8‐km stretch of coastline. This census area represents about 9% of the total suitable habitat at the island. Counts in the same area in 1994 indicated a reduction of sighted coelacanths of about 30%. Additional surveys in 1995 suggested a total coelacanth population of less than 300 individuals. The local artisanal fishery is probably responsible for the observed decline. The survival of the coelacanth seems to be severely threatened if fishing pressure is not reduced. Conservation measures should focus on providing local fishermen with fishing alternatives.

 Monitoreo Poblacional del Celacanto (Latimeria chalumnae) 

En 1991 el tamaño poblacional del celacanto,Latimeria chalumnaeen Grande Comore, al Oeste del Oceano Indico, fue estimada de 230 a 650 individuos, en base a conteos de individuos reconocidos en un estrecho costero de 8 km de longitud. Esta área de censo representa cerca de un 9% del total de hábitat adecuado en la isla. Los conteos en la zona en 1994 indicaron una reducción de celacantos de aproximadamnete un 30%. Estudios adicionales en 1995 sugirieron una población total de menos de 300 individuos. Probablemente la pesqueria artesanal local es responsable de la declinación observada. La sobrevivencia del celacanto aparenta estar amenazada si la presion por pesca no disminuye. Las medidas de conservación se deberan enfocar en proveer a los pescadores locales de alternataivas de pesca.
Application of the New Keystone‐Species Concept to Prairie Dogs: How Well Does It Work?
Authors: Kotliar Natasha B.
Published: August 2010

Abstract: It has been suggested that the keystone‐species concept should be dropped from ecology and conservation, primarily because the concept is poorly defined. This prompted Power et al. (1996) to refine the definition: keystone species have large effects on community structure or ecosystem function (i.e., high overall importance), and this effect should be large relative to abundance (i.e., high community importance). Using prairie dogs (Cynomys spp.) as an example, I review operational and conceptual difficulties encountered in applying this definition. As applied to prairie dogs, the implicit assumption that overall importance is a linear function of abundance is invalid. In addition, community importance is sensitive to abundance levels, the definition of community, and sampling scale. These problems arise largely from the equation for community importance, as used in conjunction with removal experiments at single abundance levels. I suggest that we shift from the current emphasis on the dualism between keystone and nonkeystone species and instead examine how overall and community importance vary (1) with abundance, (2) across spatial and temporal scales, and (3) under diverse ecological conditions. In addition, I propose that a third criterion be incorporated into the definition: keystone species perform roles not performed by other species or processes. Examination of how these factors vary among populations of keystone species should help identify the factors contributing to, or limiting, keystone‐level functions, thereby increasing the usefulness of the keystone‐species concept in ecology and conservation. Although the quantitative framework of Power et al. falls short of being fully operational, my conceptual guidelines may improve the usefulness of the keystone‐species concept. Careful attention to the factors that limit keystone function will help avoid misplaced emphasis on keystone species at the expense of other species.
Bat Diversity and Abundance as Indicators of Disturbance in Neotropical Rainforests
Authors: Medellín Rodrigo A. , Equihua Miguel , Amin Miguel A.
Published: August 2010

Abstract:Evaluating the degree of disturbance of any region to determine its relative importance for conservation purposes requires procedures that are relatively inexpensive and that yield accurate results fast. Because bats are abundant, diverse, and easy to sample, especially in the Neotropical rainforest, they fulfill several of the requirements of indicator species as identified in the literature. For 10 months we sampled bat communities in the Selva Lacandona in Chiapas, Mexico, at 15 sites representing five habitats. We also measured 10 variables representing vegetation structure and diversity at each site. With fuzzy‐set techniques we produced a gradient classification of disturbance for the 15 sites based on the vegetation data. We explored the relationship between vegetation conditions, described as the membership degrees in the construct “fuzzy forest set” (the complementary fuzzy set of “disturbance”), and four bat community variables. Bat species richness, number of rare bat species, and the bat diversity index were positively correlated with the vegetation scores, and relative abundance of the most abundant bat species was negatively correlated with vegetation scores. A high number of phyllostomine species in a community is a good indicator of low levels of disturbance. Although a single indicator group will probably not be sufficient for decision‐making processes in conservation, evaluating bat populations may be a good first step in assessing an area's conservation value, especially in rainforest regions.
Effects of Habitat Disturbance and Protected Areas on Mammals of Peninsular Malaysia
Authors: Laidlaw Ruth K.
Published: August 2010

Abstract:I studied a network of small forested areas (2–2744 ha) that are protected as forestry research control sites and nature reserves in Peninsular Malaysia. These areas are officially known in Malaysia as Virgin Jungle Reserves ( VJRs). They are unlogged and are usually part of a larger, generally logged forest. I examined the effects of habitat disturbance on the species richness and composition of the mammal communities in seven of these protected areas ( 70–304 ha) and in adjoining logged forest, exotic monoculture plantation, or “farm bush.” Thirty‐eight species of mammals were recorded through direct observation, identification of tracks, or other signs. The size of the remaining area of natural forest, including both logged and unlogged forest but not including exotic timber plantations, or farm bush, was the most important factor affecting the mammal communities in all seven areas. The presence of species followed a nested subset pattern. A loss of large herbivores and carnivores, in particular, was apparent between areas of natural forest of 6551 to ≥10,000 ha. When areas of natural forest of ≤459 ha were considered, size continued to be critical; a sharp loss in mammal species richness was apparent between 70 and 164 ha. The area of the natural forest in which a protected area was located largely determined the mammal species richness and composition in the protected area. Differences in habitat quality accounted for the differences in mammal communities between protected areas and their adjoining vegetation. The preservation of small undisturbed areas can effectively enhance certain mammal communities in a disturbed landscape. The survival of some mammal species, however, including the largest carnivores and herbivores, will be determined by the area of surviving forest as a whole. A positive management strategy would be to retain large, continuous areas of forest wherever possible, in preference to fragmenting forest, and to build on existing small protected‐area networks, such as the VJR network in Peninsular Malaysia, so that logged forests contain a rich mix of undisturbed protected areas.
Effects of Land‐Cover Changes on Mammals in a Neotropical Region: a Modeling Approach
Authors: Cuarón Alfredo D.
Published: August 2010

Abstract: Land‐cover changes translate into shifts in habitat available to wildlife species. I analyzed the effects of land‐cover changes on habitat availability for 54 mammal species in a 2.7 million‐ha area in southern Mexico and northern Guatemala. I considered the regional variability of these changes and the effect of variation in management and development trends. Using cluster analysis, I grouped mammal species into assemblages with similar associations of land‐cover type. Based on data from a remote‐sensing, land‐cover change analysis (1974–1986), I created simple linear Markov models for a heuristic tool to simulate land‐cover changes over a 60‐year period and to explore temporal trends of change in habitat availability for the mammal species. I used elasticity analyses to identify land‐cover transition probabilities critical for these trajectories. Of the 12 land‐cover classes considered, four dominated the area: grasslands, tropical secondary vegetation, tropical moist forests, and wetlands. Transition probabilities to and from these four land‐cover types were key in determining the availability of habitat for mammals. Thus, the relatedness of mammal species to these land‐cover types seems critical for their long‐term persistence in the region. According to general simulated trends in fluctuation of habitat availability, I classified species into seven categories: (1) opportunistic and highly adaptable species, occupying most of the area; (2) opportunistic, human‐commensal species, with restricted range in the study area; (3) species with stable and moderate habitat availability; (4) species with moderate but increasing habitat availability; (5) species with originally moderate but declining habitat availability; (6) species with already reduced and sharply declining habitat availability; and ( 7) species with declining habitat availability and a restricted range. Markovian trajectories suggest a declining trend of habitat availability for 32 species (59%). Land‐cover change trends, however, were highly variable between the nine subregions. As a result, habitat availability for many species varied regionally. Likewise, changes in management and development policies and trends in the study area will lead to contrasting habitat availability for declining and increasing species, but not for the rest of the species. The approach I used is useful for (1) assessment of land‐cover changes resulting from different development trends and management practices and (2) exploration of how changes may affect species habitat availability and survival perspectives. This examination can be accomplished for a substantial part of a biota and for entire regions, even in the context of limited information.
Utility of North Atlantic Right Whale Museum Specimens for Assessing Changes in Genetic Diversity
Authors: Rosenbaum Howard C. , Egan Mary G. , Clapham Phillip J. , Brownell Robert L. , Malik Sobia , Brown Moira W. , White Bradley N. , Walsh Peter , Desalle Rob
Published: August 2010

Abstract: We examined six historical specimens of the endangered North Atlantic right whale (Eubalaena glacialis) using DNA isolated from documented baleen plates from the late nineteenth and early twentieth centuries. Sequences from the mitochondrial DNA (mtDNA) control region from these samples were compared with those from a near‐exhaustive survey (269 of approximately 320 individuals) of the remaining right whales in the western North Atlantic Ocean. Our results suggest that there has been only relatively modest change in maternal lineage diversity over the past century in the North Atlantic right whale population. Any significant reduction in genetic variation in the species most likely occurred prior to the late nineteenth century. One historical specimen was from the last documented female capable of propagating one of the maternal lineages in the population today; no females in the existing population have been found to carry this mtDNA haplotype. Analysis of the only specimens from the eastern North Atlantic right whale population ever to be examined revealed that eastern and western North Atlantic right whales may not have been genetically differentiated populations. Loss of gene diversity experienced by North Atlantic right whales over the last century has been modest, and the six decades of protection have been successful in maintaining much of the maternal lineage diversity that was present in the late nineteenth century.
Genealogical Analysis of a Closed Herd of Black Hairless Iberian Pigs
Authors: Toro Miguel A. , Rodrigañez Jaime , Silio Luis , Rodriguez Carmen
Published: August 2010

Abstract: Livestock breeds are recognized as important components of world biodiversity. The Iberian pig is a swine breed well adapted to the Mediterranean forest ecosystem and provides cured products of high quality. The ancient population of Iberian pigs ( Sus scrofa meridionalis) was differentiated in several local types, the black hairless pigs representing the fattest genetic type. The conservation program of the Guadyerbas strain has maintained this germplasm isolated since 1945 as a closed population in an experimental herd. The complete pedigree, with 1000 breeding animals descending from 24 founders, has been used to measure along the successive cohorts of breeding animals the effective number of founders, effective number of nonfounders, founder genome equivalents, and expected number of founders' surviving alleles. For the last cohort, the values were 10.34, 1.42, 1.25, and 4.06, respectively. The evolution of inbreeding and coancestry and its components attributable to each founder were also studied. The rate of increase in inbreeding and coancestry was 2.21% per cohort, or 0.906% per year. Finally, the effect of family structure and mating tactics on the evolution of coancestry was also analyzed. The greatest rates of coancestry per cohort were attributable to unbalanced family sizes, and the use of minimum coancestry matings effectively delayed the increase in inbreeding.
Experimental Rock Outcrops Reveal Continuing Habitat Disturbance for an Endangered Australian Snake
Authors: Goldingay Ross L. , Newell David A.
Published: August 2010

Abstract: Protected areas are commonly viewed as safe havens for endangered species. To test this notion, we experimentally constructed small rock outcrops for the endangered broad‐headed snake (  Hoplocephalus bungaroides) within a national park near Sydney, Australia. Rock outcrops provide vital shelter sites during the cooler months of the year. Constructed rock outcrops (3 × 5 m) were placed at 11 paired sites located near (≤250 m) and far from (>400 m) walking tracks and roads. Eight of our 22 rock outcrops were disturbed by people over a 15‐month period. Disturbance consisted of displacement of some rocks or complete destruction of the outcrop. Disturbed outcrops occurred up to 450 m from a walking track or road. Disturbance to natural outcrops has also been observed in this park. This demonstrates a continuing decline in the quality of this snake's habitat. Twenty of our rock outcrops were colonized by velvet geckos (Oedura lesueurii), the primary prey of this snake. One broad‐headed snake was found in one outcrop. According to these findings, attempts to restore the habitat of this endangered snake should be centered on sites located ≥500 m from a walking track or road. Our study highlights the value of targeted experiments that precede larger‐scale habitat restoration.
Conservation Biology Framework for the Release of Wild‐Born Orphaned Chimpanzees into the Conkouati Reserve, Congo
Authors: Tutin Caroline E. G. , Ancrenaz Marc , Paredes Jorge , Vacher‐Vallas Myriam , Vidal Carmen , Goossens Benoît , Bruford Michael W. , Jamart Aliette
Published: August 2010

Abstract:Returning confiscated animals to their native habitats is desirable when it makes a positive contribution to the conservation of the species. Release of captive individuals is complex and controversial, however, particularly when risks are potentially high, as in the case of orphaned apes. We describe the decision‐making process that led to the successive release of 20 wild‐born orphan chimpanzees (   Pan troglodytes troglodytes) into the Conkouati Reserve in the Republic of Congo. Recommendations of the Reintroduction Specialist Group of the World Conservation Union's Species Survival Commission were followed closely. The conservation status, ecology, and behavior of wild chimpanzees; the biological, social, economic and political context of the release site; and the health and genetic status of the candidates for release were all taken into account in the planning and execution of the project. Rigorous post‐release monitoring of behavior and health allowed documentation of the outcome. The project was of benefit to the chimpanzees that were released but also brought broad benefits to the site through effective protection from poaching and deforestation, and direct and indirect benefits to local people. The genetic and behavioral diversity of chimpanzees require a variety of conservation strategies to reduce threats and maintain as many viable wild populations as possible.
Comparison of Marine and Terrestrial Protected Areas under Federal Jurisdiction in the United States
Authors: Lindholm James , Barr Brad
Published: August 2010

Abstract: There is a significant disparity in the protection of terrestrial and marine environments in the United States. Despite the considerable literature dedicated to the subject of protected areas, both terrestrial and marine, in the United States, we are not aware of work explicitly describing this dichotomy. We compared marine and terrestrial areas under federal jurisdiction to provide a quantitative assessment of the differences between the conservation of land and sea in the United States. Specifically, we compared national marine sanctuaries (including sanctuary preservation areas and ecological reserves) with national parks, national forests, and national wildlife refuges (including national wilderness preservation areas). Our results suggest that marine sanctuaries are fewer in number, smaller in total area, and smaller in percentage of area covered than are terrestrial protected areas.
Developing Classification Criteria under the U.S. Endangered Species Act: Bowhead Whales as a Case Study
Authors: Shelden Kim E. W. , Demaster Douglas P. , Rugh David J. , Olson Annette M.
Published: August 2010

Abstract:Under the U.S. Endangered Species Act, a species is classified as endangered, threatened, or recovered based on the extent to which its survival is affected by one or more of five subjective factors. A key criticism of the act is that it makes no reference to quantitative or even qualitative parameters of what constitutes “danger of extinction.” Without objective standards to guide decisionmakers, classification decisions fall prey to political and social influences. We recommend the development of species‐specific, status‐determining criteria as a means to rationalize and expedite the listing process and reclassification decisions, independent of the requirement for delisting criteria in recovery plans. Such criteria should (1) clearly define levels of vulnerability, (2) identify gaps in information on life‐history parameters, and (3) address uncertainty in existing data. As a case study, we developed preliminary criteria for bowhead whales (   Balaena mysticetus). Thresholds for endangered and threatened status were based on World Conservation Union ( IUCN) Red List criteria and population viability analyses. Our analysis indicates that particular attention must be focused on population structure within the species to appropriately classify the degree to which one or more components of a species are vulnerable to extinction. A similar approach could be used in the classification of other species. According to our application of the IUCN criteria and those developed for similar species byGerber and DeMaster (1999), the Bering Sea population of bowhead whales should be delisted, whereas the other four populations of bowheads should continue to be considered endangered.
Using Phylogenetic Diversity Measures to Set Priorities in Conservation: an Example from Southern South America
Authors: Posadas Paula , Esquivel Daniel R. Miranda , Crisci Jorge V.
Published: August 2010

Abstract:Phylogenetic diversity measures rank areas for biodiversity conservation priorities based on information encoded in phylogenies (cladograms). The goal of these ranks for conservation is to consider as many factors as possible that provide additional taxic information, such as taxa richness, taxa distributional patterns, area endemicity, and complementarity between areas. At present there are many measures that consider phylogenetic information, including node‐based, genetic‐distance, and feature‐based measures. We devised a modified phylogenetic node‐based index that we call “taxonomic endemicity standardized weight,” which considers not only the taxonomic distinctness of the taxa that inhabit a given area but their endemicity as well. Once the standardized weight of the taxonomic endemicity identifies the area of highest priority, complementarity can be used to identify the second area and so on. We used this node‐based index to rank priority areas for conservation in southern South America, and we compared the results of our rankings to results based on other node‐based indexes. Our index identified Santiago district, in Central Chile province, as the highest priority area for conservation, followed by Maule, Malvinas, and districts of Subantarctic province. Malvinas exhibits greater complementarity relative to Santiago than Maule does, however, so Malvinas is ranked second in priority. Indexes based on phylogenetic information measure the evolutionary component of biodiversity and allow one to identify areas that will ensure the preservation of evolutionary potential and phylogenetically rare taxa. The modified index we propose is sensitive to taxic distinctness and endemicity as well and allows information from diverse taxa to be combined (i.e., different cladograms). The use of complementarity allows for preservation of the maximum quantity of taxa in a minimal number of protected areas.
The Control of Biological Invasions in the World's Oceans
Authors: Bax N. , Carlton J. T. , Mathews‐Amos A. , Haedrich R. L. , Howarth F. G. , Purcell J. E. , Rieser A. , Gray A.
Published: August 2010

Abstract: The introduction of alien, or nonindigenous, animals and plants has been identified by scientists and policy makers as a major threat to biodiversity in marine ecosystems. Although government agencies have struggled to control alien species on land and freshwater for decades with mixed success, the control of alien marine species is in its infancy. Prevention of introduction and establishment must be the first priority, but many populations of alien marine species are already well established worldwide. National and international policies leave loopholes for additional invasions to occur and provide only general guidance on how to control alien species once they are established. To address this issue, a multinational group of 25 scientists and attorneys convened in 1998 to examine options for controlling established populations of alien marine species. The discussions resulted in a framework for control of alien marine species to provide decision‐making guidance to policymakers, managers, scientists, and other stakeholders. The framework consists of seven basic steps: (1) establish the nature and magnitude of the problem, (2) set objectives, (3) consider the full range of alternatives, (4) determine risk, (5) reduce risk, (6) assess benefits versus risks, and ( 7) monitor the situation. This framework can provide guidance for control efforts under the existing patchwork of national laws and can help provide a foundation for international cooperation.
Comparison of Radiocephalic Fistulas Placed in the Proximal Forearm and in the Wrist
Authors: Bhalodia Rajeshkumar , Allon Michael , Hawxby Alan M. , Maya Ivan D.
Published: August 2010

Non‐maturation is a common problem in patients receiving an arteriovenous fistula. The first vascular access choice is a distal radiocephalic fistula (dRCF) at the wrist. Patients with a failed dRCF or with vessels unsuitable for dRCF, the recommendation is to place a brachiocephalic fistula in the upper arm. Proximal forearm radiocephalic fistulas (pRCF) are created infrequently, but may permit a second forearm fistula before proceeding to the upper arm. The goal of the present study was to compare the outcomes of them. We retrospectively analyzed a computerized access database to compare the outcomes of 19 RCF and 39 dRCF placed during a 6‐month period. The baseline characteristics were similar, except those with a pRCF were more likely to have previous access and be male. Primary failure (non‐maturation) was lower for pRCF than dRCF (32 vs. 59%, p = 0.05); and excluding secondary failures, cumulative fistula survival was similar (92 vs. 86% at 1 year and 74 vs. 76% at 2 years, p = 0.56). pRCF may be an attractive alternative to a brachiocephalic fistula in patients who cannot receive a dRCF. pRCF has a lower non‐maturation rate than that of a dRCF, and a comparable cumulative survival once it is used successfully for dialysis.
Prevention of the Last Chance: An Alternative Pharmacologic Treatment of Migraine
Authors: Amery W.K. , Waelkens J.
Published: August 2010

SYNOPSIS

The hypothesis that in migraine, cyclically, an internal environment is established which ‐ beyond a certain point‐of‐no‐return ‐ gives rise to the characteristic attack, led to the evaluation of the feasibility of short‐term prevention of migraine attacks in patients who experience “warning” symptoms several hours before the actual attack. To interfere with the typical vegetative disregulation during the attack the selective dopamine receptor blocker domperidone was used. In a double‐blind cross‐over study 30 mg domperidone, taken at the very first appearance of the warning signals, was clearly superior (p<0.001) to placebo in preventing attacks: the success rates were 66% and 5% respectively.
An Epidemiological Study of Headache in an Urban Population in Zimbabwe
Authors: Levy Lorraine M.
Published: August 2010

SYNOPSIS

Information on the prevalence of headache and its characteristic features was collected from an urban population in Zimbabwe, using a combination of interview and questionnaire. Over five thousand people were questioned and the prevalence of headache was found to be 20.2% (17.6% in males and 27.0% in females). Severe headaches were experienced by approximately one third of the headache group and were more common in the younger age groups and in women. One third of the people with headaches had warning symptoms and more than half had precipitating factors. Several other features such as frequency, duration, site, age of onset and treatment sought were studied. The headaches described were classified, the most important finding being the infrequent occurrence of classical migraine.
Prevalence of Headache in Prepuberty
Authors: Sillanpää Matti
Published: August 2010

SYNOPSIS

The present study dealt with the prevalence of headache generally and migraine in particular among school children. The sample consisted of a total of 3,784 school children, accounting for 94.5% of all grade school pupils aged 13 in two Finnish cities, Tampere and Turku. The data were obtained by use of a questionnaire, filled in by the pupils according to instructions under the supervision of the class's homeroom teacher during class. Headache had occurred during 1980 in 82% of the pupils. In about one‐half (53%) of the pupils it had occurred less than once a month. It occurred monthly in 9% and weekly in 8%. Frequent headache was more common in girls than in boys and was also more commonly paroxysmal in character. Boys had had headaches more often before 1980 than during 1980, whereas in girls headaches had become more common in 1980 than before. Migraine was found to occur for 11.3% of the pupils. It was more common in girls (14.5%) than in boys (8.1%). Classic migraine, in particular, occurred more often in girls. Migraine had ceased to occur prior to 1980 in 24% of cases. In particular those attacks which involved a family history of migraine, visual aura or nausea and/or vomiting had ceased to occur. Migraine too had more commonly ceased to occur in boys (23.3%) than in girls (15.1%). Comparison with previous research showed that the occurrence of migraine had more than doubled during 25 years.
Changes in the Prevalence of Migraine and Other Headaches During the First Seven School Years
Authors: Sillanpää Matti
Published: August 2010

SYNOPSIS

Seven‐year‐old children who began school in two large Finnish cities in 1974 were investigated for the occurrence of migraine and other headache; the pupils were again surveyed at the age of fourteen. A total of 2921 pupils participated in both studies. By the age of seven, headache had occurred in 37% and migraine in 2.7%; at the age of fourteen the figures were 69% and 10.6% respectively. In the group under eight years migraine was more common in boys than in girls, but in groups older than that girls were in the majority. The prognosis for migraine which had begun before or at the age of seven was better for boys than for girls, while in girls more often than in boys migraine which began in the early school years disappeared by the age of fourteen years.
Nadolol: Its use in the Prophylactic Treatment of Migraine
Authors: Ryan Robert E. , Ryan Robert E. , Sudilovsky A.
Published: August 2010

SYNOPSIS

In the prophylactic phase of the treatment of migraine the use of beta‐blocking agents has become quite prominent within the past few years.

The circulation is responsive in both the internal and the external carotid arteries to beta‐adrenergic neuro‐transmission. It is postulated that beta‐blocking agents would be helpful in preventing vasoconstriction in the internal carotid arteries by inhibiting impulses to beta receptors in the brain; also it would prevent the excessive adrenergic vasodilation in the external carotid arteries. The beta‐adrenergic blockade thus offers an approach to the control of arterial vasodilation during the migraine attack.

The purpose of this study is to determine the relative efficacy and safety of nadolol, a new beta‐blocking agent, in reducing the frequency and or, the severity of migraine attacks as compared to placebo.

Nadolol competes specifically with beta‐adrenergic receptor antagonists for available beta‐receptor sites. This drug inhibits beta‐1 receptors, which are located chiefly in the cardiac muscle, and beta‐2 receptors, which are located chiefly in the bronchial and the vascular musculature. When access to beta‐adrenergic receptor sites is blocked by nadolol, the chronotropic, inotropic, and vasodilator responses to beta‐adrenergic stimulation are decreased proportionately. Nadolol has no intrinsic sympathomimetric activity, nor does it have an anesthetic‐like membrane stabilizing action.

The results obtained in this study, which were very encouraging, are presented, along with the side effects, which were very minimal.
The Pupil and Headaches
Authors: Herman Peter
Published: August 2010

SYNOPSIS

Pupillography before and after Cocaine eye drops was performed in twenty patients subject to vascular headaches. 65% had anisocoria which after Cocaine eye drops increased to 90%. The smaller pupil was not necessarily on the hemicrania side. Lid droop was observed in nine patients. In ten, the eyelid droop persisted after Cocaine eye drops. The pupil size was not significantly smaller than in a normal group and it was round in all but two cases. These findings suggest that patients with cluster and migraine headache have a subtle chronic sympathetic deficiency which affects both the pupil and eyelid. This deficiency may increase during the acute phase, at times causing a prominent Horner Syndrome. Adrenaline deficiency is locally responsible for these changes. No significant changes were found between cluster and vascular headache patients in this small sample. Pupillography and sympathomimetic eye drops are objective tests in the diagnosis of vascular headache in clinically difficult cases; they are a painless expedient procedure.
Clinical Characteristics of Headache in Parkinson's Disease
Authors: Indo Toshikatsu , Naito Akiko , Sobue Itsuro
Published: August 2010

SYNOPSIS

Clinical characteristics of headache in Parkinson's disease were studied. Headache was fairly concentrated in nuchal region and dull pain was the most prevalent. No correlation was found between nuchal rigidity and nuchal‐occipital pain. Pathogenesis of headache in Parkinson's disease was suspected to be somewhat different from that of muscle contraction headache.
Fetal Demise in a Migraine Patient on Propranolol
Authors: Featherstone Harvey J.
Published: August 2010

SYNOPSIS

The safety of propranolol therapy early in pregnancy is not known. A case is reported in which fatal demise occurred at 12 weeks and was related to propranolol use for migraine headaches. Propranolol has been associated with reduced umbilical blood flow in animals; this effect may be augmented and cause severe fatal ischemia in patients with the vasomotor instability of migraine.
Locked‐in Syndrome with Rapid Recovery: a Manifestation of Basilar Artery Migraine?
Authors: Sulkava Raimo , Kovanen Jussi
Published: August 2010

SYNOPSIS

A 29‐year‐old healthy woman suffered an episode of transient locked‐in syndrome followed by vomiting and headache. Based on clinical data the symptom was related to transitory ischemia probably due to basilar artery migraine. This is the first report of locked‐in syndrome in association with migraine.
Prevalence of Headache Among Nigerian University Students
Authors: Ogunyemi A.O.
Published: August 2010

SYNOPSIS

Using a questionnaire, the prevalence of headache as a primary symptom was investigated amongstudents of University of Ilorin. A total of 448 female and 1308 male students who constitute 72% and 69%respectively of the entire female and male student population of the University were studied.

61% of the females and 69% of the males suffered from recurrent headache. Classical migraine wasfound among 5.1% of the female and 3.4% of the male students respectively. Common migraine occurredabout 3 times as frequently as classical migraine. Muscle contraction ‐ Vascular headache was thecommonest type of headache and was diagnosed in 24% of the female and 33% of the male students.Tension headache affected 16.5% and 9.9% of the female and male students respectively, while clusterheadache was the affliction of 3 male students who constitute about 0.2% of the male student population.

The commonest precipitating factors for the headache were mental and physical exhaustion, heat andmental stress for female students, and for male students, they were mental stress and alcohol. It isconcluded that recurrent headache is a very common symptom among the University students of Nigeria.
Raynaud's Phenomenon Complicated by Recurrent Brain Infarction
Authors: Levy A. , Kuritzky A. , Salamon F. , Aderka D. , Matz S. , Zoldan J. , Bechar M. , Pinkhas J.
Published: August 2010

SYNOPSIS

A young patient with a family history of migraine, livedo reticularis and recurrent transient episodes of neurologic deficits is presently reported. It is possible that all three conditions are a single clinical syndrome of generalized arterial vasospasm.
Intravenous Chlorpromazine ‐ Preliminary Results In Acute Migraine
Authors: Lane RL. , Ross R.
Published: August 2010

SYNOPSIS

Acute migraine headache is a common presentation in the Emergency Department. Patients have usually taken a variety of prescription and non‐prescription medications prior to presentation ‐ narcotics, ergotamine preparations, etc. Because of the side effects and addictive potential of narcotics, an alternative was sought. Because of some theoretical attractions and encouraging early results, intravenous chlorpromazine (CPZ) was used, in small bolus injections into an established line. A retrospective analysis was conducted. This involved 40 patients, and a total of 52 emergency department visits, with a discharge diagnosis of migraine. Dose of CPZ required varied from 5–50 mg., with a mean of 21.7 mg. The therapy was completely effective on 38/52 occasions, left very mild residual headache on 11/52 occasions, and provided only mild relief on the other 3/52 occasions. Adverse effects were minimal, with most patients reporting some drowsiness and 10/52 patients reporting symptoms of hypotension. This cleared with bedrest and a short bolus of IV fluids. This degree of efficacy would appear superior to the alternative modes of therapy available, although few reports exist. It is concluded that a controlled trial is needed to fully establish this new mode of therapy.
Migraine, as Compared to Other Headaches, Is Worse During Midnight‐Sun Summer Than During Polar Night. A Questionnaire Study in an Arctic Population
Authors: Salvesen Rolf , Bekkelund Svein I.
Published: August 2010

Objective.—To investigate potential seasonal variation of migraine and other headaches in an Arctic population where light conditions are extreme during both winter and summer.

Background.—Due to the immense seasonal variation in sunlight, focus on seasonal migraine variation in a population living in an Arctic area is interesting even from a theoretical point of view.

Methods.—Northern Norway comprises the three Norwegian counties north of the Arctic Circle. There are three neurology centers in this region, which provide service for approximately half a million people. During a 2‐year period, 1403 patients (0.3% of the population) were referred to these centers for a specialist assessment of their headache. A questionnaire was mailed to all these patients; the questionnaire included questions on headache characteristics to make it possible to identify migraine according to the International Headache Society criteria. Questions on seasonal variation of headache were also included.

Results.—One thousand fifty‐two patients (75%) returned the questionnaire. Nineteen percent reported that their headaches clearly did vary with season; 11% experienced more headache during polar night, while 7% had more symptoms during midnight sun season. When the migraine and nonmigraine groups were compared, significant differences were demonstrated. Patients with nonmigrainous headache were more likely to have increased headaches during the dark winter season, while patients with migraine experienced more headache during the summer (P = .002).

Conclusions.—Patients with migraine were more likely to have headache during the bright Arctic summer season, and this distinguishes migraine from other headaches in this study. This observation may pertain to the increased light sensitivity and recently demonstrated cortical hyperexcitability in patients with migraine, and may perhaps suggest a role of the hypothalamus and/or melatonin secretion in migraine pathophysiology.
Hypnic Headache: Another Indomethacin‐Responsive Headache Syndrome?
Authors: Dodick David W. , Jones J. Michael , Capobianco David J.
Published: August 2010

Hypnic headache syndrome is a benign, recurrent, late‐onset headache disorder that occurs exclusively during sleep. Lithium has been reported to be an effective treatment, but the side effects of this medication are sometimes prohibitive, particularly in the elderly. Other drugs have been reported to be effective in this disorder, including caffeine, flunarizine, and verapamil. Recently, indomethacin has been reported to effectively suppress hypnic headaches. We report the response of seven patients with hypnic headache who were treated with indomethacin. Hypnic headache syndrome appears to represent yet another headache disorder in which there is sometimes an impressive response to indomethacin.
Spontaneous Intracranial Hypotension Successfully Treated by Epidural Patching With Fibrin Glue
Authors: Kamada Masaki , Fujita Yoshihisa , Ishii Ryoji , Endoh Sumiko
Published: August 2010

We report a case of spontaneous intracranial hypotension due to a cerebrospinal fluid leak at the C2 level, which was successfully treated by epidural fibrin glue patching. Epidural blood patching was performed twice, first with 6 mL of autologous blood and then with 10 mL, but the intracranial hypotension was unresponsive. Although successful treatment of postdural puncture headache and persistent leak after intrathecal catheterization by epidural patching with fibrin glue has been reported, fibrin glue has not been previously applied in spontaneous intracranial hypotension. Our observation suggests that epidural patching with fibrin glue should be considered in patients with spontaneous intracranial hypotension, if epidural blood patching fails to resolve the symptoms.