bluuebunny/crossref_metadata_2025 huggingface dataset:
Explicit ion modeling predicts physicochemical interactions for chromatin organization
Authors: Lin Xingcheng , Zhang Bin
Published: January 2024

Molecular mechanisms that dictate chromatin organization in vivo are under active investigation, and the extent to which intrinsic interactions contribute to this process remains debatable. A central quantity for evaluating their contribution is the strength of nucleosome-nucleosome binding, which previous experiments have estimated to range from 2 to 14 kBT. We introduce an explicit ion model to dramatically enhance the accuracy of residue-level coarse-grained modeling approaches across a wide range of ionic concentrations. This model allows for de novo predictions of chromatin organization and remains computationally efficient, enabling large-scale conformational sampling for free energy calculations. It reproduces the energetics of protein-DNA binding and unwinding of single nucleosomal DNA, and resolves the differential impact of mono- and divalent ions on chromatin conformations. Moreover, we showed that the model can reconcile various experiments on quantifying nucleosomal interactions, providing an explanation for the large discrepancy between existing estimations. We predict the interaction strength at physiological conditions to be 9 kBT, a value that is nonetheless sensitive to DNA linker length and the presence of linker histones. Our study strongly supports the contribution of physicochemical interactions to the phase behavior of chromatin aggregates and chromatin organization inside the nucleus.
Quantitative mapping of proteasome interactomes and substrates using ProteasomeID
Authors: Bartolome Aleksandar , Heiby Julia C , Di Fraia Domenico , Heinze Ivonne , Knaudt Hannah , Spaeth Ellen , Omrani Omid , Minetti Alberto , Hofmann Maleen , Kirkpatrick Joanna M , Dau Therese , Ori Alessandro
Published: January 2024

Proteasomes are essential molecular machines responsible for the degradation of proteins in eukaryotic cells. Altered proteasome activity has been linked to neurodegeneration, auto-immune disorders and cancer. Despite the relevance for human disease and drug development, no method currently exists to monitor proteasome composition and interactions in vivo in animal models. To fill this gap, we developed a strategy based on tagging of proteasomes with promiscuous biotin ligases and generated a new mouse model enabling the quantification of proteasome interactions by mass spectrometry. We show that biotin ligases can be incorporated in fully assembled proteasomes without negative impact on their activity. We demonstrate the utility of our method by identifying novel proteasome-interacting proteins, charting interactomes across mouse organs, and showing that proximity-labeling enables the identification of both endogenous and small-molecule-induced proteasome substrates.
SCC3 is an axial element essential for homologous chromosome pairing and synapsis
Authors: Zhao Yangzi , Ren Lijun , Zhao Tingting , You Hanli , Miao Yongjie , Liu Huixin , Cao Lei , Wang Bingxin , Shen Yi , Li Yafei , Tang Ding , Cheng Zhukuan
Published: January 2024

Cohesin is a multi-subunit protein that plays a pivotal role in holding sister chromatids together during cell division. Sister chromatid cohesion 3 (SCC3), constituents of cohesin complex, is highly conserved from yeast to mammals. Since the deletion of individual cohesin subunit always causes lethality, it is difficult to dissect its biological function in both mitosis and meiosis. Here, we obtained scc3 weak mutants using CRISPR-Cas9 system to explore its function during rice mitosis and meiosis. The scc3 weak mutants displayed obvious vegetative defects and complete sterility, underscoring the essential roles of SCC3 in both mitosis and meiosis. SCC3 is localized on chromatin from interphase to prometaphase in mitosis. However, in meiosis, SCC3 acts as an axial element during early prophase I and subsequently situates onto centromeric regions following the disassembly of the synaptonemal complex. The loading of SCC3 onto meiotic chromosomes depends on REC8. scc3 shows severe defects in homologous pairing and synapsis. Consequently, SCC3 functions as an axial element that is essential for maintaining homologous chromosome pairing and synapsis during meiosis.
Impact of Kidnapping and Political Instability on Investment in the Nigerian Economy
Authors: Emmanuel Anochie Okechukwu , Chukwu Nkechukwu Gabriel , Harriet Asiagwu
Published: January 2024

This study investigated the impact of kidnapping and political instability on investment in Nigerian economy. To achieve this objective, relevant data used spanning from 2006-2022 were sourced from the World Bank Indicators, and Worldwide Governance Indicators for the period under review. Preliminary test were conducted and Ordinary Least Square (OLS) regression was the analytical tool for this study. Political stability and the Absence of Violence/Terrorism Estimate (PSAVTE) were utilized as the independent variables, and Foreign Direct Investment (FDI) as a percentage of GDP was employed as the dependent variable. Based on the analysis, there exist a negative relationship between FDI, and PSAVTE, the F-statistic of the regression output stood at 1.082523 this implies that the regression plane is not statistically significant. Also, the Prob. (F-Statistic) 0.314615 is greater than the 0.05 level of significance implies that there is no statistical significant relationship between the variables. R2 = 0.067311 implies that about 6.73% of the total variation in the model specified was accounted for by the independent variables. FDI and PSAVTE are platykurtic. All the variables were stationary and significant at their respective values. No causality among the variables, thus, no existence of long-run relationship between the variables. In conclusion, kidnapping and political instability has adverse effect on investment, the fear of attack on business during conflict affects business decisions and the degree of investment. The study recommends that government must reduce the degree of unemployment in Nigeria, since a high level of unemployment promotes social vices, crime, and political instability.
Imperfect Factor Mobility, Agricultural Producer Service and Agricultural Development in Developing Economy
Authors: Chen Lihui , Wang Dianshuang
Published: January 2024

Agriculture in developing countries operates on small-scale land that hinders the utilization of modern inputs. The agricultural producer service sector which acts as an intermediate sector facilitates this process. We build a three-sector general equilibrium model to investigate the relationship between imperfect factor mobility and agricultural development by incorporating the agricultural producer service sector. Results show that a rise in capital mobility expands the agricultural sector and promotes agricultural productivity, while an increase in labour mobility cuts down the output of the agricultural sector and its productivity.
An Economic Analysis of Gerbera Under a Climate Controlled Polyhouse
Authors: Vijayalaxmi M. , Srinivasarao H.
Published: January 2024

The study was carried out ten varieties of gerbera under naturally ventilated polyhouse during Department of Horticulture, College of Horticulture, SKLTSHU, Hyderabad during the year of 2015-2016. Gerbera cultivating area in India has been increasing gradually during the last decade due to its increasing demand in the market. Polyhouse cultivation of gerbera is used to protect plants from adverse climatic conditions. The freshness and long-lasting characteristics of this flower are delight to use it in the parties, wedding functions, flower arrangements, and flower bouquets in the form of ornamental flowers. Commercial value of this flower is very high in India. Among several cut flowers grown under controlled environments, gerbera has its importance because of its unique petal colors, long vase-life and market demand. In tropical and subtropical climate, gerbera is growing in greenhouses to produce quality flower. Present study was conducted to determine the cost and returns of gerbera cultivation in polyhouse. Benefit cost ratio is an important factor which decides the optimum level of inputs to be used for maximization of production and returns in any crop. The total cost of cultivation of gerbera when cultivated under polyhouse of 1000 m2 (0.10 ha) was Rs. 394223 with an income of Rs. 875000, resulting in a BCR of 2.22. The financial feasibility tests like NPV, BCR and IRR were also positive and proved that investing on gerbera under polyhouse condition was profitable.
Mineral Profiling and Antimicrobial Effects of the West Indian Cherry (Malpighia emarginata DC.) Fruit Extracts Against Selected Pathogenic Bacteria
Authors: October Shaquana , Ansari Abdullah , Jaikishun Sirpaul , Gupta Ramwant
Published: January 2024

Bioactive compounds are found throughout the cherry fruit and these compounds give the fruits their antimicrobial properties. The objective of this study was to determine the mineral profile of M. emarginata for four maturity stages. The mineral potassium (K), phosphorus (P), and magnesium (Mg) content was evaluated by spectrophotometry. The highest amount of K was found in the half-green (HG) stage and the lowest in the full-ripe (FR). The highest concertation of P and Mg was found in the full-green (FG) stage and the lowest in the full-ripe. For P, there was an increase from the FG to the HG maturity stage, then the concentration declined until maturity, as it related to the concentration of Mg and K, there was a decline in the concentration as the fruit progressed maturity. Additionally, the antibacterial activity of the fruit extract was conducted on E. coli and S. aureus using the Kirby Bauer disc diffusion method at different concentrations of plant extracts.  The ethanolic extracts (EE) (zone of inhibition 13.4 ± 1.9 to 21.8 ± 0.6) showed more antimicrobial activity than the aqueous extract (AE) with zones of inhibition diameters (mm) which ranged from 0 ± 0 to 18.2 ± 0.8.  Both AE and EE were effective against S. aureus bacteria strain except the AE (crude) which had no zone of inhibition. All tested microorganisms were susceptible to the antibiotic ciprofloxacin. This study suggests that other types of solvents were used to investigate the antibacterial activities of the M. emarginata extract on a wider array of bacteria as the fruit demonstrated antimicrobial properties.
Part Optimisation using CNC Milling Techniques and Finite Element Analysis
Authors: Yearwood Abdu , Manohar Krishpersad , Khan Basheer , Liu Stephen , Quintyn Colin , Sharief Safrawz
Published: January 2024

Aims/Objectives: Increasing demand for optimised, lightweight, and efficient products has become a necessity in the field of engineering. As such, integrating appropriate design processes in engineering education has become crucial for aspiring engineers and practice. In this study, the application of design for manufacturing, finite element analysis, and design for environment principles in the redesign of a motorcycle brake lever was considered. The objective was to enhance its structural performance while reducing material usage compared to the original part.
Results: The re-engineered part achieved a significant reduction in mass, minimising its environmental impact, while maintaining an acceptable Factor of Safety (FOS) in comparison to the original design. The Von Mises stress, initially concentrated at a critical arch, was reduced from 54.3 MPa to 27.3 MPa and translated to the pinned region. This effectively eliminated bending moments at critical regions. Additionally, the maximum displacement was reduced, resulting in shorter machining timeframes.
Conclusion: Applied systematic optimisation processes demonstrated the possibility of achieving better products with improved safety factors, reduced material usage, and enhanced manufacturing efficiency. The findings and methodologies presented provide critical guidelines for aspiring engineering students and offered valuable insights into the integration of advanced design principles in engineering education and manufacturing.
Impact of Mobile Technology on Extension Service Delivery in Remote Farming Communities: A Review
Authors: Ananda K R  , D R K Saikanth  , Chaudam Vaishnavi , Sravani Settipalli , Nayak S Harshitha , Dam Adrita , Shukla Anoop
Published: January 2024

This scientific paper presents an in-depth analysis of the integration of mobile technology in agricultural extension services, illustrating its pivotal role in revolutionizing information dissemination and management in agriculture. It commences with a detailed overview of various mobile technologies such as smartphones, SMS, voice messaging, and mobile internet, and their profound impact on the agricultural sector. The study progresses to examine diverse modes of technology delivery, including direct communication methods like voice calls and SMS, multimedia approaches like videos and podcasts, and interactive services such as chatbots and forums. This is followed by an evaluation of the impact of these technologies on extension service delivery, focusing on their reach, speed, cost-effectiveness, and resource utilization, and how they compare to traditional extension methods. The paper provides empirical insights through case studies and real-world examples, including successful implementations like Kenya's M-Kilimo service and more challenging projects like Nigeria's AgroMobile, offering a nuanced understanding of the factors influencing success and failure. A comparative analysis is conducted to contextualize the use of mobile technology in agricultural extension services globally, considering different socio-economic and technological environments. The study concludes by exploring emerging trends and future innovations in mobile technology, such as artificial intelligence (AI) and the Internet of Things (IoT), and proposes strategic recommendations for enhancing its application in extension services. These recommendations include advancing digital literacy, tailoring technology to local contexts, and fostering supportive policy environments. This comprehensive examination underscores mobile technology's critical role in advancing agricultural practices, enhancing farmer engagement, and contributing to sustainable agricultural development.
Spillover Effects of Covid-19 Induced Lockdown on Onion Prices in India
Authors: Garai Sandip , Paul Ranjit Kumar , Paul Amrit Kumar
Published: January 2024

In a normal situation onion prices vary in a highly unprecedented way in India. So, it is worth noticing the effect of an uncertain situation on onion prices. In this article an efficient Artificial Intelligence (AI) tool, i.e., Support Vector Regression (SVR) has been used to predict the price fluctuation of onion over the lockdown period, unlock condition and the period including the pre-pandemic situation. Results obtained are compared with prediction of traditional Multiple Linear Regression (MLR) model. Several metrices such as , Root Mean Squared Error (RMSE), Mean Absolute Deviation (MAD), and Relative Mean Absolute Percentage Error (RMAPE) have been used for this purpose. The result of Machine Learning (ML) algorithm indicates that in the nationwide lockdown condition pandemic indicator variables are having more than 70% influence on the onion price variability. The effect is reduced to near about 60% in unlock condition and if considering the whole year data this effect is near about 45%. The results also indicate that ML algorithm is more efficient to capture the variability than the traditional model.
Studies of globalization and equity in post-Soviet Russia
Authors: Ilyin Mikhail
Published: February 2004

The article reports on the progress of Russian research on globalization and equity. Building on Stain Roekan’s classification of social cleavages, the author identifies several schools in Russian globalization studies. He then discusses how the distinctions of authority—people, church—state, land—industry, owners—workers, metropolis—colony, and network—hierarchy find their reflection in current Russian research. The article shows that Russian scholars have recently engaged in a series of discussions of globalization’s equity criteria and their application to democratic governance, utilizing the world system’s approach, civilization analysis, and the theory of Kondratieff’s cycles.
Geopolitics in Russia—science or vocation?
Authors: Solovyev Eduard G.
Published: February 2004

The author describes the development of geopolitical studies in Russia after the Soviet breakup. He identifies two main schools of geopolitical analysis, Traditionalist and Revisionist. Traditionalism is inspired by old European and Russian geopolitical theories and views the world through the lenses of confrontation over power and resources. The revisionist school, on the other hand, adopts a considerably broader definition of what constitutes geopolitics by proposing to study various forms of organizing space on a global scale. According to the paper’s central argument, the Russian geopolitics, while having emerged as a vocation, it is yet to turn into a full-fledged academic discipline. It continues to lack coherent and scientifically testable theoretical propositions and needs a broad discussion of its issues with the participation of both traditionalists and revisionists.
Molecular tools for studies on the transmission biology ofEchinococcus multilocularis
Authors: DEPLAZES P. , DINKEL A. , MATHIS A.
Published: February 2004

Two novel approaches for diagnosis of intestinalEchinococcus multilocularisinfection, the detection ofE. multilocularis-specific coproantigens in ELISA and of copro-DNA by PCR, have been successfully implemented. These methods have proven their value for thepost mortemand theintra vitamdiagnosis ofE. multilocularisin definitive hosts. They have also made novel approaches possible to study the transmission biology of the parasite as they allow detection of the infection in faecal samples collected in the environment. Coproantigen detection is the diagnostic method of choice as it is sensitive, fast and cheap. Studies on faecal samples collected in the field revealed that coproantigen detection did reflect the different prevalences in fox populations as assessed from foxes at necropsy and also the effect of deworming efforts in foxes as achieved by long-term distribution of praziquantel-containing baits. The use of PCR for routine diagnostic or large-scale purposes is hampered by the fact that DNA extraction from faecal material is a very laborious task. Therefore, PCR is rationally used for confirmatory purposes of copro-antigen-positive samples. As taeniid eggs cannot further be differentiated morphologically, PCR is the method of choice to identifyE. multilocularisinfections in faecal or environmental samples containing taeniid eggs. In intermediate rodent hosts, PCR is routinely used in epidemiological studies for identifyingE. multilocularisfrom liver lesions which are often very small, atypical or calcified.
Multi-scale spatial analysis of human alveolar echinococcosis risk in China
Authors: DANSON F. M. , GRAHAM A. J. , PLEYDELL D. R. J. , CAMPOS-PONCE M. , GIRAUDOUX P. , CRAIG P. S.
Published: February 2004

Risk factors for the transmission of Echinococcus multilocularis to humans operate at a range of spatial scales. Over a large area, such as China, regional scale risk is correlated with variation in climatic conditions because of its effect on the spatial distribution of landscapes that can support E. multilocularis transmission in wildlife hosts and the probability of egg survival. At a local scale of a few kilometres, or tens of kilometres, transmission risk is related to the spatial proximity of human populations and landscapes with active transmission. At the patch scale, when considering individual villages or households, human behavioural factors are important and for individuals genetic and immunological factors play a role. Satellite remote sensing can provide landscape information at a range of spatial scales and provide a spatial framework within which to examine transmission patterns. This paper reviews the application of remotely sensed data and spatial data analysis to develop a better understanding of disease transmission and shows how such data have been used to examine human alveolar echinocossosis infection patterns, at a range of spatial scales, in an endemic area in central China.
Echinococcosis on the Tibetan Plateau: prevalence and risk factors for cystic and alveolar echinococcosis in Tibetan populations in Qinghai Province, China
Authors: SCHANTZ P. M. , WANG H. , QIU J. , LIU F. J. , SAITO E. , EMSHOFF A. , ITO A. , ROBERTS J. M. , DELKER C.
Published: February 2004

Infections by larval stages of tapeworms of the genus Echinococcus (echinococcosis or hydatid disease) are zoonotic infections of major public health importance throughout much of the world. Humans become infected through accidental ingestion of eggs passed in faeces of canid definitive hosts. Tibetan populations of China have some of the highest documented levels of infections by both Echinococcus granulosus and E. multilocularis, the causes of cystic and alveolar echinococcosis, respectively. In this study we measured the prevalence of cystic (CE) and alveolar (AE) echinococcosis disease in Tibetan communities in Qinghai, Province, China, and identified putative risk factors for both infections in these communities. 3703 volunteers in three predominately Tibetan counties of Qinghai were surveyed between June 1997 and June 1998. Parasitic lesions were diagnosed by imaging of characteristic space-occupying lesions in abdominal organs (ultrasound) or the lungs (radiographs). Specific serodiagnostic assays (Dot-ELISA and Em2-ELISA) were performed on sera of positively imaged subjects to further distinguish the disease agent. All participants completed a questionnaire documenting age, sex, education level, occupation, lifestyle (nomadic or settled), slaughter practices, drinking water source, hygienic practice and association with dogs. Data were analyzed using SAS version 8. 6·6% of the volunteers had image-confirmed infection with E. granulosus (CE) and 0·8% had E. multilocularis (AE) infection. The significant univariate factors for echinococcal infection (both CE and AE) included livestock ownership, Tibetan ethnicity, female gender, low income, herding occupation, limited education, water source, age greater than 25 years old, poor hygienic practices, offal disposal practices and dog care. Multivariate analysis revealed that livestock ownership was a significant risk factor for both forms of the disease, as well as age greater than 25 years, female gender, herding occupation, and being nomadic (vs semi-nomadic or settled). No additional significant risk factors were identified among the 344 nomadic participants. Being female and being older than 25 years of age were significant factors among the 1906 semi-nomadic participants. Among the 1445 settled participants, allowing dogs to sleep indoors was statistically significant. Issues such as inadequate assessment of animal ownership, selection bias, disease misclassification, and loss of information may have led to reduction in strength of some risk factor associations and need to be addressed in future epidemiologic analysis of echinococcosis in this population.
Echinococcosis: disease, detection and transmission
Authors: CRAIG P. S. , ROGAN M. T. , CAMPOS-PONCE M.
Published: February 2004

Echinococcosis is one of the world's most geographically widespread parasitic zoonoses, with transmission occurring in tropical, temperate and arctic biomes. Most human infections are due toEchinococcus granulosustransmitted between domestic dogs and livestock, but this cosmopolitan species also cycles between wild carnivores (principally canids) and wild ungulates. The other species with significant zoonotic potential isE. multilocularisthat occurs naturally in fox definitive hosts and small mammal intermediate hosts. These two species cause human cystic or alveolar echinococcosis respectively, which may be considered serious public health problems in several regions including developed countries. This review provides an introductory overview to the Supplement and summarises the biology and epidemiology of these two related cestodes with an emphasis on applied aspects relating to detection, diagnosis and surveillance in animal and human populations, and includes aspects of transmission ecology, and also considers aspects of community epidemiology and potential for control.
Children's difficulty in learning homonyms
Authors: DOHERTY MARTIN J.
Published: February 2004

Mazzocco (1997) claimed that children have persistent difficulty in learning pseudo-homonyms – words like rope used to refer to a novel object (e.g. spade). Because the novel objects were familiar, the pseudo-homonyms in her study were also synonyms (i.e. rope and spade both now mean spade). The results could therefore be due to children's well-known difficulties in learning synonyms. In Experiment 1, 55 six- to ten-year-olds used story context to select referents for pseudo-homonyms from picture sets containing the intended referents, with primary referents amongst the distractors. Children were equally poor when the intended referents were familiar (e.g. spade) as when they were unfamiliar (e.g. tapir) – 35 and 38% correct, respectively. This indicates that familiarity of referent does not account for children's difficulties. In Experiment 2, 64 five- to ten-year-olds received instruction about homonymy, then a story set without pictures of the primary referents, in order to make the experimenter's intentions clear. Children were then shown one of the story sets from Experiment 1. Performance was just as poor (38% correct), indicating that misunderstanding of task demands did not account for failure. The conclusion is that Mazzocco's findings represent a psychologically interesting developmental difficulty.
Where's the orange? Geometric and extra-geometric influences on English children's descriptions of spatial locations
Authors: RICHARDS LYNN V. , COVENTRY KENNY R. , CLIBBENS JOHN
Published: February 2004

The effect of both geometric and extra-geometric factors on children's production of in is reported (free-response paradigm). Eighty children across four age groups (means 4;1, 5;5, 6;1, and 7;1) were shown video scenes of puppets placing real objects in various positions with reference to a bowl and a plate. Located objects were placed at three heights on top of piles of other objects in the scene. The extra-geometric factor of location control of the located object was manipulated by comparing static scenes to dynamic scenes in which the located object was depicted as either moving independently of, or together with, the reference object. Additionally, the located object was placed on other objects that were either the same or different (e.g. an apple on apples or on oranges). The results indicate that even the youngest children altered the way they talked according to not only geometric but also extra-geometric factors.
Syntactic–semantic interface in the acquisition of verb morphology
Authors: WEIST RICHARD M. , PAWLAK ALEKSANDRA , CARAPELLA JENELL
Published: February 2004

The purpose of this research was to show how the syntactic and semantic components of the tense–aspect system interact during the acquisition process. Our methodology involved: (1) identifying predicates, (2) finding the initial occurrence of their tense–aspect morphology, and (3) observing the emergence of contrasts. Six children learning Polish and six children learning English, found in the CHILDES archives, were investigated. The average starting age of the children learning English was 1;11, and 1;8 for the children learning Polish. In the first analysis, we traced the same 12 verbs in both languages, and in the second analysis, we contrasted the acquisition patterns for a set of telic versus atelic predicates. We tracked the verbs/predicates from the starting age to 4;11 or the child's final transcript. In English, progressive aspect is the marked form, and in Polish, perfective aspect is the marked form. This typological distinction has a significant effect of the acquisition patterns in the two languages. We argue that children acquire a multi-dimensional system having deictic relations as one of the basic dimensions. This process can be best understood within a functional theoretical framework having a well-defined syntactic–semantic interface.
Predation risk is associated with the geographic variation of a sexually selected trait in a viviparous fish (Xenotoca variata)
Authors: Moyaho Alejandro , Garcia Constantino Macías , Manjarrez Javier
Published: February 2004

Male secondary sexual traits may increase the risk of predation because mating signals make them conspicuous to predators and hamper evasive manoeuvres. Males of Xenotoca variata, a viviparous freshwater fish, show on their flanks bright and colourful spots (speckles), the number of which varies geographically. In this study, the association of this variation with the presence of the piscivorous snake Thamnophis melanogaster, which co‐occurs with X. variata, was investigated. A test was also done to establish whether the snake distinguishes between male fish with contrasting numbers of speckles and if the perception of speckles is influenced by water turbidity. The amount of speckling and the prevalence of snakes in key localities was assessed by using one‐way mirrors, and the effect of speckles on the predatory responsiveness of snakes was evaluated by presenting them with pairs of male fish in clear and in turbid water. In localities where snakes were infrequent there was a tendency for male fish to have many speckles. The snakes preferentially approached the males with more speckles than the males with fewer speckles. The direction of the preference did not change with the conditions of the water, but the magnitude was stronger in clear water than in turbid water. The snakes also approached first the males with more speckles. These findings indicate that predation risk by T. melanogaster may select against speckles and produce population differentiation.
Activity patterns of the common dormouse (Muscardinus avellanarius) in different Mediterranean ecosystems
Authors: Panchetti Fabiana , Amori Giovanni , Carpaneto Giuseppe M. , Sorace Alberto
Published: February 2004

The seasonal activity of the common dormouse Muscardinus avellanarius was studied in three different habitat types of central Italy: a deciduous beech wood dominated by Fagus sylvatica (Cimini Mountains), and a deciduous oak woodland with Quercus cerris and Q. pubescens and an evergreen wood dominated by holm oak Q. ilex, both along the central Tyrrhenic coast. In each site, 50 nest‐boxes were fixed to trees and were monitored monthly for 2 years (May 1998–April 2000). In the beech wood site, the species showed an annual biological cycle similar to that described for populations of central and northern Europe: dormancy in winter, from the first 10 days of November to the end of December; end of hibernation in the first half of April; reproduction between May and July. On the contrary, in the two coastal sites, nest‐boxes were occupied from October to June, and the breeding period was in autumn, showing that a winter dormancy phase is absent, probably owing to the mild winter. On the other hand, no dormice or new nests were observed in nest‐boxes in summer suggesting that a dormancy phase occurred in summer, probably owing to dry climatic conditions. Two patterns of biological cycle therefore emerged from the results: a temperate pattern in beech forest with winter dormancy and spring reproduction, and a Mediterranean pattern in coastal habitats with autumnal reproduction, winter activity and summer dormancy.
Ease and effectiveness of costly autotomy vary with predation intensity among lizard populations
Authors: Cooper William E. , Pérez‐Mellado Valentín , Vitt Laurie J.
Published: February 2004

Costly anti‐predatory defences are used in ecological time and maintained in evolutionary time by natural selection favouring individuals that survive through their use. Autotomy of expendable body parts is a striking example of a defence having multiple substantial costs, including loss of ability to use the same defence, loss of energy, and decreased growth, reproductive success and survival following autotomy, plus the energetic cost of replacing the lost body part in species capable of regenerating them. Our study shows that autotomy in the lacertid lizard Podarcis lilfordi reduces sprint speed, indicating decreased capacity to escape as well as the loss of energy. Autotomy carries substantial cost, and thus should be avoided except as a last resort. Ease of autotomy and post‐autotomic movements were studied in three populations of lacertid lizards. Two were islet populations of P. lilfordi from Aire (lowest predation pressure) and Colom (intermediate predation pressure) off Minorca. The third was a mainland population of Podarcis hispanica, a closely related species from the mainland of the Iberian Peninsula where predation pressure is higher than on the islets. As predicted, a suite of autotomic traits increases the effectiveness of autotomy as a defence as predation pressure increases. With increasing predation pressure, the frequency of voluntary autotomy increases, latency to autotomy decreases, pressure on the tail needed to induce autotomy decreases, vigour of post‐autotomic tail movements increases, and distance moved by the shed tail increases. Additional changes that might be related to predation pressure, but could have other causes, are the presence of tail coloration contrasting with body coloration except under the lowest predation pressure (Aire) and longer tails in the mainland species P. hispanica. Correspondence between predation pressure and the suite of autotomic traits suggests that autotomy is an important defence that responds to natural selection. Comparative data are needed to establish the generality of relationships suggested in our study of only three populations.
One thousand jaguars (Panthera onca) in Bolivia's Chaco? Camera trapping in the Kaa‐Iya National Park
Authors: Maffei Leonardo , Cuéllar Erika , Noss Andrew
Published: February 2004

This paper reports on efforts to trap jaguars Panthera onca on camera in the dry forests of the Kaa‐Iya del Gran Chaco National Park in Bolivia. Ad hoc camera trapping provided certain information on jaguar presence and habits, but was limited in application. Activity patterns showed that jaguars are active all day, particularly at one of three sites, with peaks in the morning and evening the more common pattern. Minimum observed home range was variable, with males (up to 65 km2) occupying more area than females (up to 29 km2). The authors adapted systematic methodologies first developed to survey tigers in India, based on individually distinctive pelage patterns in tigers and jaguars. Abundance is estimated using capture–recapture statistical analysis, and a sample area defined based on the maximum distance that individual jaguars move during the sample period. The methodology has proved successful for jaguars in dry Chaco forest, population densities of 1/30–45 km2 and 1/20 km2 are estimated in the two most extensive landscape systems of Kaa‐Iya. The entire 34 400 km2 protected area is estimated to sustain a population of over 1000 adult and juvenile jaguars, the largest single population of jaguar reported anywhere, and a viable population for long‐term jaguar conservation.
Communing with ‘the laity’: exceptionalism, postmodernism and the urban biography
Authors: CROLL ANDY
Published: February 2004

For as historians are compelled to grind out their specified quota of specialized articles and inaccessible monographs, which are at best read only by a handful of professional colleagues, and are at worst almost completely ignored, this makes them less and less able to fulfil that essential public function which remains their real and abiding justification: satisfying the interest and furthering the comprehension of that broader, non-professional audience memorably described by Hugh Trevor-Roper as ‘the laity’ (David Cannadine, 1999).
Identity, competition and place promotion in the Five Towns
Authors: STOBART JON
Published: February 2004

This article argues that cultural capital in the Victorian town contributed to spatial as well as social differentiation, helping to bolster the power of civic elites and the image and identity of the town. Evidence drawn from north Staffordshire Pottery towns demonstrates how the value of cultural capital reflected the scale, timing and geography of investment, and its ability to represent and communicate the taste and judgment of the civic elite to those of neighbouring towns. In the hothouse of local rivalry that led up to the creation of the borough of Stoke-on-Trent, investment in cultural capital took on extra significance as each town strove for political ascendancy in the nascent conurbation.
Ethnicity and the city: the Kurdish quarter of Damascus between Ottoman and French rule, c. 1724–1946
Authors: FUCCARO NELIDA
Published: February 2004

This article concentrates on the Kurdish quarter of Damascus and investigates the relationship between communal/ethnic identity, spatial organization and the socio-political structures of the city. It challenges the notion of quarter as an ‘ethnic cluster’ by examining historical processes of integration of the Kurdish community in the body politic of Damascus. In the colonial period the emergence of new arenas of public action for the Kurdish community are analysed with reference to the emergence of new ideas of class and community.
Robust garden path parsing
Authors: ROARK BRIAN
Published: February 2004

This paper presents modifications to a standard probabilistic context-free grammar that enable a predictive parser to avoid garden pathing without resorting to any ad-hoc heuristic repair. The resulting parser is shown to apply efficiently to both newspaper text and telephone conversations with complete coverage and excellent accuracy. The distribution over trees is peaked enough to allow the parser to find parses efficiently, even with the much larger search space resulting from overgeneration. Empirical results are provided for both Wall St. Journal and Switchboard test corpora.
Shallow seismogenic zone detected from an offshore‐onshore temporary seismic network in the Esmeraldas area (northern Ecuador)
Authors: Pontoise B. , Monfret T.
Published: February 2004

For a given site, many factors control the seismic risk. Earthquake magnitude, hypocentral distance, rupture mechanism, site effects and site vulnerability are among the most important. This article deals with one of these factors: the depth of the seismogenic zone, in the northern Ecuadorian subduction system, beneath a highly vulnerable site, the city of Esmeraldas and its industrial complex, the Ecuadorian oil refinery and shipping terminal. To address this problem, we analyzed data from a three weeks passive seismological experiment, conducted in the spring of 1998, using 13 Ocean Bottom Seismometers and 10 portable land‐stations. A preliminary interpretation of wide‐angle data obtained in the fall of 2000, in the Manta area, 100 km South of the study area, unambiguously indicates the presence of a velocity inversion in the Ecuadorian margin velocity structure. This velocity inversion is characterized by a shadow‐zone of ∼1 s on the record‐sections, and is interpreted as the result of a velocity contrast between the upper plate structure and the sedimentary and basaltic layer II of the subducted oceanic Nazca plate. One‐dimensional velocity models are deduced from these wide‐angle data and are used for earthquake location in the Esmeraldas area. This highly improved the hypocentral parameter determinations. The updip limit of the seismogenic zone is found at a depth of ∼12 km, 35 km eastward of the trench, and the depth of the seismogenic zone below the Esmeraldas city is found at ∼20 km. This shallow depth of the seismogenic zone dramatically increases the seismic hazard of the area.
Toward an optimal geomagnetic field intensity determination technique
Authors: Yu Yongjae , Tauxe Lisa , Genevey Agnès
Published: February 2004

Paleointensity determinations based on double heating techniques (in‐field/zero‐field cooling, zero‐field/in‐field cooling, and two in‐field steps with opposite laboratory fields) are generally considered to be functionally interchangeable producing equally reliable paleointensity estimates. To investigate this premise, we have developed a simple mathematical model. We find that both the zero‐field first and in‐field first methods have a strong angular dependence on the laboratory field (parallel, orthogonal, and anti‐parallel) while the two in‐field steps method is independent of the direction of the laboratory‐produced field. Contrary to common practice, each method yields quite different outcomes if the condition of reciprocity of blocking and unblocking temperatures is not met, even with marginal (10%) tails of partial thermoremanence. Our calculations suggest that the zero field first method with the laboratory‐produced field anti‐parallel to the natural remanence (NRM) is the most robust paleointensity determination technique when the intensity of the lab‐induced field is smaller than ancient field. However, the zero field first method with the laboratory‐field parallel to the NRM is the optimum approach when the intensity of the lab‐induced field is larger than the ancient field. By far the best approach, however, is to alternatethe infield‐zerofield (IZ) steps with zerofield‐infield (ZI) steps.
Improved detection of large cirrus particles from infrared spectral observations
Authors: Mahesh Ashwin
Published: February 2004

Spectral observations of cirrus clouds can be analyzed to obtain cloud particle effective radii using measurements at select wavenumbers in the infrared atmospheric window. The suitability of these wavenumbers to determine a range of sizes is constrained by the dependence on particle radius of ice absorption efficiency (Qabs). By using only those wavenumbers at which Qabs varies monotonically with radius, cloud particle radii up to approximately 20 μm can be determined; larger values, however, present problems. At some wavenumbers, the variation in Qabs is not sufficiently large to distinguish between large particle radii. At other wavenumbers, larger particles are more easily distinguished, but Qabs values do not correspond to unique particle radii. Using one set of wavenumbers only to determine whether the particle is large or small, and a second set to actually determine the effective radius of a large cloud particle, the limitations faced at individual wavenumbers can be partially overcome. This is demonstrated using yearlong spectral observations of ice clouds at South Pole station.
Eastern equatorial Pacific Ocean T‐S variations with El Niño
Authors: Wang Ou , Fukumori Ichiro , Lee Tong , Johnson Gregory C.
Published: February 2004

Temperature‐Salinity (T‐S) relationship variability in the pycnocline of the eastern equatorial Pacific Ocean (NINO3 region, 5°S–5°N, 150°W–90°W) over the last two decades is investigated using observational data and model simulation. A numerical model simulation using the MITgcm (Massachusetts Institute of Technology General Circulation Model) suggests that, during El Niño years, the water in the eastern equatorial Pacific Ocean becomes saltier (by 0.1 to 0.2) and warmer (by 0.5 to 1°C) on density surfaces within the pycnocline. This simulation is consistent with Conductivity‐Temperature‐Depth (CTD) data collected mostly during Tropical Atmosphere Ocean (TAO) mooring maintenance cruises.
Inversion of massive surface wave data sets: Model construction and resolution assessment
Authors: Debayle Eric , Sambridge Malcolm
Published: February 2004

A new scheme is proposed for the inversion of surface waves using a continuous formulation of the inverse problem and the least squares criterion. Like some earlier schemes a Gaussian a priori covariance function controls the horizontal degree of smoothing in the inverted model, which minimizes some artifacts observed with spherical harmonic parameterizations. Unlike earlier schemes the new approach incorporates some sophisticated geometrical algorithms which dramatically increase computational efficiency and render possible the inversion of several tens of thousands of seismograms in few hours on a typical workstation. The new algorithm is also highly suited to parallelization which makes practical the inversion of data sets with more than 50,000 ray paths. The constraint on structural and anisotropic parameters is assessed using a new geometric approach based on Voronoi diagrams, polygonal cells covering the Earth's surface. The size of the Voronoi cells is used to give an indication of the length scale of the structures that can be resolved, while their shape provides information on the variation of azimuthal resolution. The efficiency of the scheme is illustrated with realistic uneven ray path configurations. A preliminary global tomographic model has been built for SV wave heterogeneities and azimuthal variations through the inversion of 24,124 fundamental and higher‐mode Rayleigh waveforms. Our results suggest that the use of relatively short paths (<10,000 km) in a global inversion should minimize multipathing, or focusing/defocusing effects and provide lateral resolution of a few hundred kilometers across the globe.
High‐pressure and high‐temperature measurements of electrical conductivity in basaltic rocks from Mount Etna, Sicily, Italy
Authors: Scarlato Piergiorgio , Poe Brent T. , Freda Carmela , Gaeta Mario
Published: February 2004

We have investigated the electrical properties of Etnean rocks by in situ complex impedance spectroscopy using a multianvil apparatus. From these measurements we determined the electrical conductivity of a lava flow sample, whose basaltic composition can be considered close to that of the parent magma and also that of a mafic nodule representative of the high‐density cumulates interpreted as responsible for the main high‐velocity anomaly observed beneath the volcano. The electrical conductivities of the two samples were measured at pressures of 0.9 and 1.5 GPa and temperatures from 400 to 1100°C at frequencies from 0.1 to 105 Hz. To investigate the electrical properties of the Etnean products as a function of partial melting, a few experiments were performed in a piston‐cylinder apparatus prior to the electrical measurements. The obtained data were approximated using an equivalent circuit fitting technique. For the lava flow sample, electrical conductivity displays Arrhenian behavior over the entire investigated temperature range, with an activation energy of ∼0.8 eV. Within the uncertainties of our measurements, we do not observe any effect of pressure on conductivity between 0.9 and 1.5 GPa. On the contrary, experiments performed on the series of partially molten samples indicate that conductivity increases with increasing quantity of glass. While conductivities of samples with minor amounts of glass are comparable to that of the lava flow starting material, with increased melting, conductivity can increase by as much as a factor of 3. The mafic nodule was observed to have a conductivity higher than the lava flow sample (e.g., at 800°C and 0.9 GPa, a factor of 4 higher). However, scatter in the data is somewhat higher in comparison to the lava flow sample, most likely because of the coarse texture of the samples and a consequence to their chemical and structural heterogeneity. Using our results, we illustrate the effects that a layer of hot magma surrounded by a cooler wall rock has on apparent resistivities determined by one‐dimensional forward calculations. Our modeling demonstrates that both size and depth of magmatic intrusions strongly influence apparent resistivity and that these parameters can be extracted from field data if the electrical properties of the rocks below the surface are well understood.