bluuebunny/crossref_metadata_2025 huggingface dataset:
Authors: Birchok Daniel Andrew
Published: January 2008

For centuries descendents of people from the region of Hadramawt on the southern Arabian Peninsula have navigated the Indian Ocean and inhabited its far-flung littorals. Engseng Ho's The Graves of Tarim offers an anthropological history of these Hadramis, in particular the ‘Alawī Sayyids, one line of the Prophet Muhammad's descendants through his daughter Fāt˙ima and cousin ‘Alī. Beginning in the graveyards of Tarim, a town in Hadramawt where some of the earliest ‘Alawī ancestors are buried, Ho describes genealogical rituals developed at the turn of the fifteenth century used to “presence” those buried there, bringing the living into contact with the dead. These practices, which Ho identifies with a complex of Sufi practices (t˙arīqa) called “the ‘Alawī Way,” took on new resonances as a Hadrami diaspora, “a society of the absent,” spread across the Indian Ocean. Its members, like the buried ‘Alawī ancestors at Tarim, required constant “revivification.” For some this was achieved through genealogies associated with the ‘Alawī Way, transformed and reworked on journeys, which sometimes spanned generations, away from, returning to, and circumventing Tarim.
Authors: Cattelino Jessica R.
Published: January 2008

Scholars of money often take for granted its instrumentality. Deborah Valenze argues that this is a mistake, for it overlooks the historical contingency and variability in money's uses, meanings, and discourses. In this book, Valenze examines money in seventeenth- and eighteenth-century England, demonstrating how and when money took its “modern” social and moral form. By doing so, she opens up theoretical questions about the relationship of money to mobility and constraint, the potential of money to create hierarchy and limit freedom even while it affords new relationships and movements, and the role of money as a moral and social measure of self in everyday life. The abstracting power and the unstable meanings of money, Valenze contends, shaped early modern British culture in sometimes contradictory ways.
Determining optimum planting dates for pearl millet for two contrasting environments using a modelling approach
Authors: SOLER C. M. T. , MAMAN N. , ZHANG X. , MASON S. C. , HOOGENBOOM G.
Published: January 2008

Pearl millet [Pennisetum glaucum (L) R. Br.] is an important cereal crop in Niger, West Africa and a potential crop for the United States of America (USA). Only a few studies have been conducted in either country to identify the optimum planting dates for high and stable yields, in part because planting date experiments are resource-intensive. Crop simulation models can be an alternative research tool for determining optimum planting dates and other management practices. The objectives of the present study were to evaluate the performance of the Cropping System Simulation Model (CSM)–CERES-Millet model for two contrasting environments, including Mead, Nebraska, USA and Kollo, Niger, West Africa and to use the model for determining the optimum planting dates for these two environments. Field experiments were conducted in both environments to study the impact of nitrogen fertilizer on grain yield of three varieties in Kollo and three hybrids in Mead and their associated growth and development characteristics. The CSM–CERES-Millet model was able to accurately simulate growth, development and yield for millet grown in these two contrasting environments and under different management practices that included several genotypes and different nitrogen fertilizer application rates. For Kollo, the optimum planting date to obtain the maximum yield was between 13 and 23 May for variety Heini Kirei, while for the other varieties the planting dates were between 23 May and 2 June. For Mead, the planting date analysis showed that the highest simulated yield was obtained, on average, between 19 and 29 June for hybrid 59022A×89-083 and 1361M×6Rm. Further studies should focus on evaluation and application of the millet model for other agroclimatic regions where pearl millet is an important crop.
Modelling bovine spongiform encephalopathy
Authors: THORNLEY J. H. M. , FRANCE J.
Published: January 2008

A deterministic model for the spread of an important animal disease, bovine spongiform encephalopathy (BSE), is described. It is a sparse three-pool model, the pools corresponding to susceptible, infected and sick animals. Simulations illustrate the biological meaning of the parameters, and pinpoint how parameters affect epidemic characteristics: infectivity impacts on the leading edge of the epidemic and its intensity. The times when infection is introduced and when control is exercised determine the length and possibly the intensity of the epidemic. Finally, the (single) incubation rate influences the trailing edge of the epidemic. It is applied to data describing the recent UK BSE outbreak, with reasonable success. Apart from a scaling factor, only these four quantities were adjusted to achieve this. The contributions from greater modelling complexity are discussed. It is concluded that the simple model is well suited for grasping the essentials, whereas further detail is needed for a more mechanistic representation, in particular concerning incubation delays in developing infectiousness and clinical sickness.
Population pharmacokinetic modelling of the enterohepatic recirculation of diclofenac and rofecoxib in rats
Authors: Huntjens D R H , Strougo A , Chain A , Metcalf A , Summerfield S , Spalding D J M , Danhof M , Della Pasqua O
Published: January 2008

Background and purpose:

Enterohepatic recirculation (EHC) is a common pharmacokinetic phenomenon that has been poorly modelled in animals. The presence of EHC leads to the appearance of multiple peaks in the concentration‐time profile and increased exposure, which may have implications for drug effect and extrapolation across species. The aim of this investigation was to develop a population pharmacokinetic model for diclofenac and rofecoxib that describes EHC and to assess its consequence for the pharmacodynamics of both drugs.

Experimental approach:

The pharmacokinetics of diclofenac and rofecoxib was characterized in male rats following intravenous, intraperitoneal and oral administration. Blood samples were collected at pre‐defined time points after dosing to determine plasma concentrations over time. A parametric approach using nonlinear mixed effects modelling was applied to describe EHC, whilst simulations were used to evaluate its impact on PGE2inhibition.

Key results:

For diclofenac, EHC was described by a compartmental model with periodic transfer rate and metabolite formation rate. For rofecoxib, EHC modelling required a conversion compartment with first‐order recycling rate and lag time. Based on model predictions, EHC causes an increase of 95% in the systemic exposure to diclofenac and of 15% in the exposure to rofecoxib. In addition, EHC prolongs the inhibition of PGE2and increases the duration of the anti‐inflammatory effect (24 h for rofecoxib 10 mg kg−1) without affecting maximum inhibition.

Conclusions and implications:

Our findings show the relevance of exploring EHC in a quantitative manner to accurately interpret pharmacodynamic findingsin vivo, in particular when scaling across species.

British Journal of Pharmacology(2008)153, 1072–1084; doi:10.1038/sj.bjp.0707643; published online 14 January 2008
ZP120 causes relaxation by pre‐junctional inhibition of noradrenergic neurotransmission in rat mesenteric resistance arteries
Authors: Simonsen U , Laursen B E , Petersen J S
Published: January 2008

Background and purpose:

ZP120 (Ac‐RYYRWKKKKKKK‐NH2), is a new partial nociceptin/orphanin FQ (NOP) receptor agonist with sodium‐potassium sparing aquaretic effects. The mechanisms of vasodilatation of ZP120 were examined in rat mesenteric resistance arteries.

Experimental approach:

Arterial segments (internal diameters 206±4 μm,n=224) were mounted in microvascular myographs for isometric tension recordings and electrical field stimulation (EFS).

Key results:

ZP120 and the endogenous NOP receptor ligand, N/OFQ, did not relax arteries contracted with noradrenaline or adenosine‐triphosphate. EFS‐evoked contractions were inhibited by a purinoceptor antagonist, suramin, and the α1‐adrenoceptor antagonist prazosin. N/OFQ inhibited, concentration‐dependently, EFS‐evoked contractions with a maximal effect of 52±3% (n=8) at 1 μM. The maximal effect of 1 μMZP120 was lower (27±5%,P<0.05,n=9) than for N/OFQ. Endothelial removal or pretreatment with capsaicin did not influence the vasodilator effects of ZP120 and N/OFQ. ZP120 and N/OFQ responses were preserved in the presence of suramin. The α2‐adrenoceptor antagonist, rauwolscine, antagonized the effect of clonidine and brimonidine, but ZP120 and N/OFQ inhibition of EFS‐evoked contraction was unaltered. The competitive NOP receptor antagonist, UFP‐101 (10 μM), prevented the inhibitory effect of N/OFQ, but not ZP120 suggesting that N/OFQ and ZP120 have distinct modes of interaction with the NOP receptor.

Conclusions and implications:

Our findings suggest that the vasodilator effect of ZP120 and N/OFQ in rat mesenteric resistance arteries is mediated by prejunctional inhibition of adrenergic neurotransmission. These properties, that promote diuresis and attenuate the cardiovascular consequences of increased sympathetic nerve activity, make ZP120 a promising drug candidate.

British Journal of Pharmacology(2008)153, 1185–1194; doi:10.1038/sj.bjp.0707688; published online 14 January 2008
Quantitative analysis of ultra thin layer growth by time-of-flight low energy ion scattering
Authors: Primetzhofer D. , Markin S. N. , Zeppenfeld P. , Bauer P. , Prusa S. , Kolibal M. , Sikola T.
Published: January 2008

Time of flight low energy ion scattering is used to quantitatively characterize the growth mode of Au deposited on B. Information on the filling factor (surface area coverage) is deduced from the yield of backscattered ions and the spectrum height of scattered neutrals. From the variation of the filling factor with the nominal Au thickness, cluster growth is deduced. Information on the average cluster height is obtained from the energy distribution of scattered neutrals and the comparison with computer simulation. Finally, an estimate of the aspect ratios is obtained for the clusters from the filling factor and the cluster height.
Negative magnetoresistance in ultrananocrystalline diamond: Strong or weak localization?
Authors: Choy T. C. , Stoneham A. M. , Ortuño M. , Somoza A. M.
Published: January 2008

Electronic transport of ultrananocrystalline diamond involves the interplay between disorder, Anderson localization, and phase coherence. We show that variable range hopping explains many key features of the conductivity including the large low temperature negative magnetoresistance. Our numerical studies suggest two regimes where the (negative) magnetoresistance varies with magnetic field B such as B2 or B1∕2, respectively, depending on the ratio of the cyclotron orbital radius and the hopping distance. This agrees with experiment, which also points to the expected T−1∕2 temperature dependence of the hopping distance at the critical field.
Self-assembled deoxyguanosine based molecular electronic device on GaN substrates
Authors: Liddar H. , Li J. , Neogi A. , Neogi P. B. , Sarkar A. , Cho S. , Morkoç H.
Published: January 2008

Nanoscale hybrid molecular organic photodetectors based on self-assembled guanosine molecules conjugated to wide-bandgap GaN semiconductors has been realized in the ultraviolet wavelength regime. Metal-semiconductor-metal based photodetector is fabricated using ordering of modified guanosine based semiconductor nanowires which exhibit I-V characteristics with high current response and higher rectification ratio compared to Si based hybrid photodetectors. Photocurrent response of a two-terminal device shows the typical characteristics of a semiconductor photodiode with a cutoff wavelength at ∼325nm. The I-V characteristics have been elucidated using the induced polarization properties of self-assembled guanosine semiconductor.
Tuning of the electrical parameters of a twisted-nematic display material by using electron beam irradiation
Authors: Dhar R. , Verma Rohit , Rath M. C. , Sarkar S. K. , Wadhawan V. K. , Dabrowski R. , Tykarska M.
Published: January 2008

Electron beam irradiation studies on 4′-pentyl-4-cyanobiphenyl (5CB) have been carried out. Dielectric measurements demonstrate that even a low level of irradiation (beyond a critical dose of ∼6kGy) results in a dramatic increase in the transverse component of the dielectric permittivity, and a corresponding decrease in the dielectric anisotropy. It is shown that the changes in dielectric parameters due to the irradiation can be fruitfully utilized to control the display performance of the device to a certain extent. The observed change in the dielectric parameters is attributed to the formation of a donor-acceptor type charge-transfer complex due to the irradiation.
Small torsional piezoelectric fiber actuators with helical electrodes
Authors: Pan C. L. , Feng Z. H. , Ma Y. T. , Liu Y. B.
Published: January 2008

Small piezoelectric fibers wound with helical electrodes on their outer surface will produce torsional displacement. A piece of piezoelectric tube with an outer diameter of 1mm, a wall thickness of 0.1mm, and an effective axial length of 40mm was used as a prototype actuator’s body, while two pieces of copper wires of 40μm diameter were used as the electrodes. After poled with 2kV∕mm electric field strength, the prototype actuator produces 1.7° torsional angle when it was driven from −500to500V. A resonant frequency as high as 10kHz was observed on this actuator.
Spin cast ferroelectric beta poly(vinylidene fluoride) thin films via rapid thermal annealing
Authors: Kang Seok Ju , Park Youn Jung , Sung Jinwoo , Jo Pil Sung , Park Cheolmin , Kim Kap Jin , Cho Beong Ok
Published: January 2008

We describe a method of fabricating ferroelectric beta-type poly(vinylidene fluoride) (PVDF) thin films on Au substrate by the humidity controlled spin casting combined with rapid thermal treatment. Our method produces thin uniform ferroelectric PVDF film with ordered beta crystals consisting of characteristic needlelike microdomains. A capacitor with a 160nm thick ferroelectric PVDF film exhibits the remanent polarization and coercive voltage of ∼7.0μC∕cm2 and 8V, respectively, with the temperature stability of up to 160°C. A ferroelectric field effect transistor also shows a drain current bistablility of 100 at zero gate voltage with ±20V gate voltage sweep.
Evidence of hot electrons generated from an AlN∕GaN high electron mobility transistor
Authors: Tripathy Suvranta K. , Xu Guibao , Mu Xiaodong , Ding Yujie J. , Wang Kejia , Cao Yu , Jena Debdeep , Khurgin Jacob B.
Published: January 2008

We have observed that the temperature of the electrons drifting under a relatively high electric field in an AlN∕GaN-based high-electron-mobility transistor is significantly higher than the lattice temperature (i.e., the hot electrons are generated). These hot electrons are produced through the Fröhlich interaction between the drifting electrons and long-lived longitudinal-optical phonons. By fitting electric field versus electron temperature deduced from the measurements of photoluminescence spectra to a theoretical model, we have deduced the longitudinal-optical-phonon emission time for each electron is to be on the order of 100fs.
Impedance spectroscopy investigation of electron transport in solar cells based on blend film of polymer and nanocrystals
Authors: Huang Wenbo , Peng Junbiao , Wang Li , Wang Jian , Cao Yong
Published: January 2008

Bulk heterojunction solar cells, consisting of the active film of poly[2-methoxy,5-(2-ethylhexoxy)-1,4-phenylene vinylene] (MEH-PPV) doped with cadmium selenium (CdSe) nanoparticles, were fabricated and investigated using impedance spectroscopy (IS) technique. The spectroscopy displayed a phenomenon of negative imaginary impedance (NII) related to the inductive effect in low frequencies in the device with low CdSe concentrations, and the NII phenomenon may disappear with increasing the CdSe concentrations. We propose an equivalent circuit to explain the IS and deduce that the NII phenomenon is related to inadequate channels for electron transport in the blend film of CdSe nanocrystals and MEH-PPV. The method based on the IS is available to probe the formation of a continuous network for electron transport in the nanocrystal dispersed polymer system.
GaN-based two-dimensional surface-emitting photonic crystal lasers with AlN∕GaN distributed Bragg reflector
Authors: Lu Tien-Chang , Chen Shih-Wei , Lin Li-Fan , Kao Tsung-Ting , Kao Chih-Chiang , Yu Peichen , Kuo Hao-Chung , Wang Shing-Chung , Fan Shanhui
Published: January 2008

GaN-based two-dimensional (2D) surface-emitting photonic crystal (PC) lasers with AlN∕GaN distributed Bragg reflectors are fabricated and demonstrated. The lasing threshold energy density is about 3.5mJ∕cm2 per pulse under optical pumping at room temperature. Only one dominant emission wavelength of 424.3nm with a narrow linewidth of 1.1Å above the threshold is observed. The laser emission covers whole circularly 2D PC patterns (50μm in diameter) with a small divergence angle. The lasing wavelength emitted from 2D PC lasers with different lattice constants occurs at the calculated band-edges provided by the PC patterns. The characteristics of large area, small divergence angle, and single mode emission from the GaN-based 2D surface-emitting PC lasers should be promising in high power blue-violet emitter applications.
Structural and magnetic studies of Fe/W metallic superlattices (abstract)
Authors: Boufelfel A. , Emrick Roy M. , Falco Charles M.
Published: January 2008

We have sputter deposited Fe/W superlattices on several types of substrates using magnetically enhanced dc sputtering guns. The deposition rates were controlled to better than 0.3%. We used a 6-MV Rutherford backscattering facility to determine the chemical composition with 0.5% relative uncertainty. We varied the modulation wavelength from Λ=4.4 to 250 Å, keeping the number of atomic layers equal for both materials. Structural characterization was achieved by several x-ray diffraction techniques. We found that the superlattice structural coherency breaks down below Λc=21.5 Å, although the multilayered structural periodicity still holds below this value. We used conversion electron Mössbauer spectroscopy to measure the intrinsic hyperfine magnetic field of the samples at room temperature. The data was fitted with two independent methods which show very good agreement. We observed a decrease in the hyperfine field value as the modulation wavelength Λ decreases, and a disappearance for Λ<Λc. This effect is interpreted as due to structural strains of the whole superlattice and electronic structure changes at the interfaces.
Using morphological traits to identify persistent lucernes for dryland agriculture in NSW, Australia
Authors: Boschma S. P. , Williams R. W.
Published: January 2008

This paper reports on several studies conducted to better understand the variability between lucerne cultivars and lines, and use this to predict persistence in dryland grazing pastures in eastern Australia. Morphological traits of 20 cultivars/lines were measured in irrigated and dryland spaced plant experiments. Studies were also conducted to describe variation among lucernes in their utilisation of starch and responses to water deficit, pests and diseases. Multiple regression analyses were used to develop simple models where the measured traits could be used to predict persistence of lucerne lines in dryland evaluation experiments.
Although there was significant variation among cultivars/lines in most measured traits, no single trait reliably predicted persistence of cultivars/lines in dryland evaluation experiments. However, variation in persistence at both sites could be explained by models developed by multiple regression using differences in the mean lengths of the longest stems at 10% flower in summer and winter. Persistent lucernes were those that had relatively long stems in summer and short stems in winter. Water use efficiencies, starch utilisation patterns and resistances to pests and diseases of different lucernes provided some improvement to this simple model, but these improvements were not consistent.
Additive genetic variance for stem strength in field pea (Pisum sativum)
Authors: Beeck C. P. , Wroth J. , Cowling W. A.
Published: January 2008

Weak stem strength in field pea (Pisum sativum) is a major restriction to yield, seed quality and ease of harvest. Three aspects of stem strength: load at breaking point, flexion and compressed stem thickness, showed substantial genetic variation among a diverse range of six parents including modern cultivars, landrace accessions, and interspecific progeny. Diallel analysis of parents and F1 progeny was conducted using a simple additive-dominance model, which was adequate for load and compressed stem thickness. There were significant additive genetic effects for load and compressed stem thickness with no evidence of dominance or maternal effects, and also significant additive genetic effects for flexion which was subject to more complex genetic control. Valuable alleles for these stem strength traits were present in commercial cultivars and landrace types of field pea. Efficient and practical breeding for improved stem strength will involve several recurrent selection cycles with moderate selection pressure for compressed stem thickness in early generations, followed by verification of improvements in lodging resistance in subsequent field trials. Compressed stem thickness is relatively easy to measure on individual plants in the field and is closely associated with load.
Response of representative cover crops to aluminum toxicity, phosphorus deprivation, and organic amendment
Authors: Vieira Frederico C. B. , He Zhenli L. , Wilson Patrick C. , Bayer Cimélio , Stoffella Peter J. , Baligar Virupax C.
Published: January 2008

This study aimed to: (1) determine the effect of P depletion and presence of Al on root and shoot growth of representative cover crops, and on their nutrient uptake; (2) characterise the composition of root exudation under P and Al stress in nutrient solution; (3) evaluate the ability of aqueous extracts of composts in reducing Al phytotoxicity. Plants of cowpea (Vigna unguiculata subsp. unguiculata), black oat (Avena strigosa), and lablab (Lablab purpureous) were cultivated in different nutrient solution compositions and concentrations for 3 weeks. It was found that Al at concentration of 20 and 200 µmol/L increased citrate exudation at least 8 and 24 times, respectively, for cowpea and 18 and 36 times, respectively, for lablab, as compared with the blank. However, no release of organic acids occurred due to P deprivation, suggesting that citrate exudation was a specific response to excess Al. No response in organic acid release was observed for black oat under the stress of P deficiency or Al toxicity. Although the presence of Al in solution did not significantly affect chlorophyll content in leaves, it decreased root and shoot weight, as well as root length, surface area, volume, and number of tips. Organic extracts alleviated aluminum toxicity, improving plant growth and ameliorating plant nutrition status. Yard waste extract was more effective in enhancing plant growth than GreenEdge extract in plants under Al stress.
Companion crop performance in relation to annual biomass production, resource supply, and subsoil drying
Authors: Harris R. H. , Crawford M. C. , Bellotti W. D. , Peoples M. B. , Norng S.
Published: January 2008

A field experiment located in NE Victoria compared the productivity of cereals sown into mature lucerne (companion crop) with cereals and lucerne grown as monocultures. Additional nitrogen (N) and water was applied to investigate if increased resource supply could alleviate competition and improve cereal performance in the presence of lucerne. Cereal plant populations, lucerne and cereal biomass, and cereal grain yields and protein were measured throughout the experiment. Soil water content was also monitored over time to determine whether companion cropping compromised the ability of lucerne to extract deep soil water. While companion cropping depressed both lucerne and cereal production, the combined annual biomass production was greater than cereal and lucerne when grown alone. Averaged over the three seasons, companion cropping resulted in a 31% increase (P < 0.05) in total annual biomass compared with the lucerne monoculture, and an 18% increase compared with the cereal monoculture in the 2004–05 and 2005–06 seasons. Cereals growing with lucerne produced fewer tillers, spikes and consequently cereal biomass compared with cereals growing as a monoculture. Therefore, companion crops yielded 25% less (P < 0.05) grain compared with the cereal monoculture over the 3-year study. Competition for N and light in the pre-cereal stem elongation period, were likely causes. Increasing the supply of N and water did not result in a main treatment (monoculture v. companion crop) by additional resource interaction, indicating that cereal responses were the same irrespective of lucerne’s presence. The application of N, water and these combined inputs, resulted in a 13–40%, 35% and 49% increase (P < 0.05) in cereal grain yields, respectively. While companion cropping compromised lucerne’s capacity to extract water from deep soil layers to a degree, this practice was still able to maintain drier subsoil in comparison to the cereal monoculture.
Hydraulic lift by canola plants aids P and K uptake from dry topsoil
Authors: Rose T. J. , Rengel Z. , Ma Q. , Bowden J. W.
Published: January 2008

The role of hydraulic lift in nutrient uptake from dry topsoil is unclear. Vertically-split root systems were used to measure hydraulic lift and phosphorus (P) and potassium (K) uptake at the rosette and flowering stages of two canola (Brassica napus L.) cultivars (Trigold and Boomer with small and large root systems, respectively) grown in soil low in P and K. Rubidium (Rb) was used as a tracer to examine K uptake from K fertiliser banded in dry topsoil. During vegetative growth, statistically significant hydraulic lift was measured, irrespective of cultivar root size or a specific nutrient (P or K) placed in the topsoil. The Rb tracer revealed significant amounts of K were absorbed from the dry soil, but at rates five-fold lower than from the moist soil. The water lifted could not prevent cessation of P uptake by Boomer and a reduction in P uptake by Trigold. During mid to late flowering, ion uptake from the dry topsoil was impeded despite the continuation of hydraulic lift up to 28 days after the topsoil was dried. Minimal fine root growth following topsoil drying (and reduction in fine root biomass in some treatments) appeared to be the primary cause of impeded nutrient uptake.
A genetic locus targeted to the nuclear periphery in living cells maintains its transcriptional competence
Authors: Kumaran R. Ileng , Spector David L.
Published: January 2008

The peripheral nuclear lamina, which is largely but not entirely associated with inactive chromatin, is considered to be an important determinant of nuclear structure and gene expression. We present here an inducible system to target a genetic locus to the nuclear lamina in living mammalian cells. Using three-dimensional time-lapse microscopy, we determined that targeting of the locus requires passage through mitosis. Once targeted, the locus remains anchored to the nuclear periphery in interphase as well as in daughter cells after passage through a subsequent mitosis. Upon transcriptional induction, components of the gene expression machinery are recruited to the targeted locus, and we visualized nascent transcripts at the nuclear periphery. The kinetics of transcriptional induction at the nuclear lamina is similar to that observed at an internal nuclear region. This new cell system provides a powerful approach to study the dynamics of gene function at the nuclear periphery in living cells.
Cohesin Smc1β determines meiotic chromatin axis loop organization
Authors: Novak Ivana , Wang Hong , Revenkova Ekaterina , Jessberger Rolf , Scherthan Harry , Höög Christer
Published: January 2008

Meiotic chromosomes consist of proteinaceous axial structures from which chromatin loops emerge. Although we know that loop density along the meiotic chromosome axis is conserved in organisms with different genome sizes, the basis for the regular spacing of chromatin loops and their organization is largely unknown. We use two mouse model systems in which the postreplicative meiotic chromosome axes in the mutant oocytes are either longer or shorter than in wild-type oocytes. We observe a strict correlation between chromosome axis extension and a general and reciprocal shortening of chromatin loop size. However, in oocytes with a shorter chromosome axis, only a subset of the chromatin loops is extended. We find that the changes in chromatin loop size observed in oocytes with shorter or longer chromosome axes depend on the structural maintenance of chromosomes 1β (Smc1β), a mammalian chromosome–associated meiosis-specific cohesin. Our results suggest that in addition to its role in sister chromatid cohesion, Smc1β determines meiotic chromatin loop organization.
A syntaxin 10–SNARE complex distinguishes two distinct transport routes from endosomes to the trans-Golgi in human cells
Authors: Ganley Ian G. , Espinosa Eric , Pfeffer Suzanne R.
Published: January 2008

Mannose 6-phosphate receptors (MPRs) are transported from endosomes to the Golgi after delivering lysosomal enzymes to the endocytic pathway. This process requires Rab9 guanosine triphosphatase (GTPase) and the putative tether GCC185. We show in human cells that a soluble NSF attachment protein receptor (SNARE) complex comprised of syntaxin 10 (STX10), STX16, Vti1a, and VAMP3 is required for this MPR transport but not for the STX6-dependent transport of TGN46 or cholera toxin from early endosomes to the Golgi. Depletion of STX10 leads to MPR missorting and hypersecretion of hexosaminidase. Mouse and rat cells lack STX10 and, thus, must use a different target membrane SNARE for this process. GCC185 binds directly to STX16 and is competed by Rab6. These data support a model in which the GCC185 tether helps Rab9-bearing transport vesicles deliver their cargo to the trans-Golgi and suggest that Rab GTPases can regulate SNARE–tether interactions. Importantly, our data provide a clear molecular distinction between the transport of MPRs and TGN46 to the trans-Golgi.
Locus-specific and activity-independent gene repositioning during early tumorigenesis
Authors: Meaburn Karen J. , Misteli Tom
Published: January 2008

The mammalian genome is highly organized within the cell nucleus. The nuclear position of many genes and genomic regions changes during physiological processes such as proliferation, differentiation, and disease. It is unclear whether disease-associated positioning changes occur specifically or are part of more global genome reorganization events. Here, we have analyzed the spatial position of a defined set of cancer-associated genes in an established mammary epithelial three-dimensional cell culture model of the early stages of breast cancer. We find that the genome is globally reorganized during normal and tumorigenic epithelial differentiation. Systematic mapping of changes in spatial positioning of cancer-associated genes reveals gene-specific positioning behavior and we identify several genes that are specifically repositioned during tumorigenesis. Alterations of spatial positioning patterns during differentiation and tumorigenesis were unrelated to gene activity. Our results demonstrate the existence of activity-independent genome repositioning events in the early stages of tumor formation.
The microtubule-based motor Kar3 and plus end–binding protein Bim1 provide structural support for the anaphase spindle
Authors: Gardner Melissa K. , Haase Julian , Mythreye Karthikeyan , Molk Jeffrey N. , Anderson MaryBeth , Joglekar Ajit P. , O'Toole Eileen T. , Winey Mark , Salmon E.D. , Odde David J. , Bloom Kerry
Published: January 2008

In budding yeast, the mitotic spindle is comprised of 32 kinetochore microtubules (kMTs) and ∼8 interpolar MTs (ipMTs). Upon anaphase onset, kMTs shorten to the pole, whereas ipMTs increase in length. Overlapping MTs are responsible for the maintenance of spindle integrity during anaphase. To dissect the requirements for anaphase spindle stability, we introduced a conditionally functional dicentric chromosome into yeast. When centromeres from the same sister chromatid attach to opposite poles, anaphase spindle elongation is delayed and a DNA breakage-fusion-bridge cycle ensues that is dependent on DNA repair proteins. We find that cell survival after dicentric chromosome activation requires the MT-binding proteins Kar3p, Bim1p, and Ase1p. In their absence, anaphase spindles are prone to collapse and buckle in the presence of a dicentric chromosome. Our analysis reveals the importance of Bim1p in maintaining a stable ipMT overlap zone by promoting polymerization of ipMTs during anaphase, whereas Kar3p contributes to spindle stability by cross-linking spindle MTs.
Effect of Xiphinema diversicaudatum on the growth of four seedling grasses
Authors: ROBERTS HELEN , COTTON J.
Published: January 2008

In pot experiments in a glasshouse, nematode numbers equivalent to 1000 Xiphinema diversicaudatum (Micol.) Thome per litre of soil produced extensive galling on roots of seedling perennial ryegrass and tall fescue. Roots of cocksfoot and timothy had significantly fewer galls. At 1000 X. diversicaudatum per litre of, soil, the maximum root length in ryegrass, tall fescue and cocksfoot was significantly less, by 28, 25 and 22 per cent respectively, than in the uninoculated plants, and ryegrass and tall fescue had significantly fewer crown roots than the controls. The effects on shoot growth were small.
The influence of sowing depth on the removal of grain from winter wheat by starlings
Authors: BOYCE D. V. M.
Published: January 2008

The effect of sowing depth on the probability of grain removal from winter wheat by starlings (Sturnus vulgaris L.) was tested at four sites in Humberside during 1977. At each site there was an inverse relationship between sowing depth and the probability of grain removal ranging from 91 per cent probability at depths of 21–30 mm to 21 per cent Probability at depths of 41–45 mm.
Insensitivity of Botrytis cinerea to iprodione, procymidone and vinclozolin and their uptake by the fungus
Authors: PAPPAS A. C. , COOKE B. K. , JORDAN V. W. L.
Published: January 2008

An isolate of Botrytis cinerea Pers. ex Fr. insensitive to vinclozolin, procymidone and iprodione was obtained from strawberries which had been inoculated with a benomyl‐insensitive isolate of the pathogen and sprayed with iprodione. This isolate maintained its insensitivity to benomyl and also showed resistance to quintozene and dicloran. Tests on detached strawberry fruits showed that the iprodione‐insensitive isolate was as virulent as a sensitive isolate. No difference was found in the amounts of the fungicides taken up by the insensitive and sensitive isolates of the fungus.
Chemical control of blackberry mite, Acalitus essigi (Hassan)
Authors: ALFORD D. V.
Published: January 2008

Experiments in eastern England in 1975, 1977 and 1978 confirmed that endosulfan was an effective alternative to endrin for control of blackberry mite, Acalitus essigi (Hassan) (Acari: Eriophyidae), a cause of uneven ripening (‘redberry’) of blackberries. Three pre‐flowering sprays of 0 05 or 0–1 per cent endosulfan, applied at about 14‐day intervals, reduced the incidence of ‘redberry’ to an acceptable level; two sprays about four weeks apart were generally less effective. Endosulfan residues in fruits at harvest were below detectable levels. Carbaryl, chlorpyrifos, dicofol, vamidothion and ZR‐856 were not effective when tested in a preliminary trial in 1975.
Systematic Knowledge Auditing: A Case Study in a Power Utility Company
Authors: Shek W. Y. , Cheung C. F. , Lee W. B. , Chong Y. Y.
Published: January 2008

Managing knowledge of plant maintenance in a power utility company is vital to the provision of a safe and reliable electricity supply to two million domestic and commercial customers. The business is built on a lot of expertise, techniques and experience of all of its employees from engineering, maintenance, safety and environmental control, to quality assurance. Knowledge auditing is usually carried out as the first critical step in the implementation of any Knowledge Management programmes in power utility companies. Although various knowledge auditing approaches have been proposed by some researchers and practitioners, there is a lack of a systematic approach in the way it is conducted, and the audit practice varies with different industries and companies. This paper presents a systematic knowledge audit approach, which has been successfully trial-implemented in a power plant.
Effects of Social Identity Processes on Coordination and Knowledge Sharing in Geographically Distributed Software Teams
Authors: Gokakkar Raghavendra
Published: January 2008

Distributed work environment suffers issues such as lack of mutual knowledge, ineffective knowledge sharing, lack of trust and coordination and interpersonal conflicts. The author conducted an empirical investigation in two projects each employing a hybrid offshore software development model to gain a deeper understanding of the underlying issues. The case study approach allowed for the study of phenomenon in a real-work context. Open-ended semi-structured interviews were conducted as a primary means of data collection. An interpretive analysis using a framework of social identity theory revealed that the in-group/out-group effect generated by a geographical faultline was further severed or diluted by two factors: individual mobility — a realistic opportunity to become a member of other group and the common expertise between two sub-teams. The study concluded with an observation that the absence of these factors resulted in strong group stereotypes, which in turn caused stronger inter-group behaviour.
The Role of Middle Managers in Knowledge Transfer
Authors: Carty Robert , Walsh Siobhan
Published: January 2008

This paper examines the causes of knowledge loss in a company undergoing a process of radical change. Using a methodology based on a single case study, the research highlights the critical role of middle managers in facilitating knowledge transfer. Middle managers facilitate both socialisation mechanisms for knowledge transfer and the maintenance of knowledge transfer systems based on information technology. The findings of the research suggest that eliminating layers of middle management will inevitably lead to knowledge loss, with consequential implications for competitive advantage. Based on the findings, a typology linking knowledge transfer to organisational forms is proposed.
Stratigraphy, structure and volcanology of the SE Deccan continental flood basalt province: implications for eruptive extent and volumes
Authors: JAY ANNE E. , WIDDOWSON MIKE
Published: January 2008

The Deccan Volcanic Province is one of the world's largest continental flood basalt provinces, and derives additional importance because its eruptions (64–67 Ma) straddle the Cretaceous–Tertiary boundary. To better assess the environmental impact of Deccan volcanism, and its possible effect upon Cretaceous–Tertiary boundary biota, it is necessary to document the stratigraphy, chronology and volume of the eruptions. New chemostratigraphical data permit mapping of the SE Deccan. These data strengthen the likelihood that the Rajahmundry Traps of eastern India were originally fed by long-distance flows, and are an extension of the Main Deccan Volcanic Province. An east–west cross-section reveals a depression or ‘moat’ around the SE periphery of the Deccan Volcanic Province. This provided a site in which shallow lakes initially formed, and along which later lava eruptions became channelled and confined. Published palaeomagnetic data indicate that the lavas of the SE Deccan were erupted during Chron 29R, coeval with the Cretaceous–Tertiary boundary, and the chemostratigraphic data place the associated lake sediments (i.e. Lameta Group) beneath and within lavas of the Wai Subgroup. Finally, these new map data are combined with previous work to provide a quantitative estimate for the original Deccan Volcanic Province eruptive volume of
c
. 1.3 × 10
6
km
3
.
Silurian–Devonian active-margin deep-marine systems and palaeogeography, Alai Range, Southern Tien Shan, Central Asia
Authors: Pickering K.T. , Koren T.N. , Lytochkin V.N. , Siveter D.J.
Published: January 2008

Analysis of Mid-Palaeozoic successions in the northern part of the Alai Range (Kyrgyzstan and bordering Uzbekistan), Southern Tien Shan, Central Asia, has identified a Silurian–Devonian deep-marine depositional system of basin-slope facies-associations. Here, we document the stratigraphy and sedimentology of a region in Central Asia that, through conflict, has become inaccessible for geological research. The turbidite-dominated Pul'gon Formation (Silurian) accumulated in sea-floor depressions and within the inferred basin axis. The large-scale, coarse clastic lenses of the Dzhidala Formation (mostly Devonian) represent the fills of submarine channels, canyons or gullies of the palaeoslope; other slope apron processes include sediment slides, debris flows and olistoliths. The partly time-equivalent condensed sequences of the Mid- to Late Silurian Kursala Formation and Early Devonian Tamasha Formation represent graptolitic mudstone and chert accumulation, respectively, together with thin dolomitic limestones, that accumulated over
c
. 10–15 Ma, probably on seamounts in the Turkestan (Fergana) Ocean between the continental margin of Kazakhstania and the Alai microcontinent. The graptolitic shale-rich Chakush Formation (early Silurian) is geographically and petrographically different from the Pul'gon and Dzhidala formations and suggests a different provenance (opposing continental margin or seamount talus).
Ion microprobe zircon U–Pb age and geochemistry of the Myanmar jadeitite
Authors: SHI GUANGHAI , CUI WENYUAN , CAO SHUMIN , JIANG NENG , JIAN PING , LIU DUNYI , MIAO LAICHENG , CHU BINGBING
Published: January 2008

Combined geochemistry and geochronology of the Myanmar jadeitite were determined. Bulk-rock trace element compositions display U-shaped REE patterns with pronounced positive Eu anomalies. The total REE abundances are very low, less than half chondritic, and the high field strength elements and some large ion lithophile elements are moderately enriched. These features indicate a metasomatic origin. There are three groups of zircons with different interior characteristics, cathodoluminescence, mineral inclusions, chemical compositions and sensitive high-resolution ion microprobe U–Pb ages. Group-I zircons, with a mean age of 163.2 ± 3.3 Ma, mostly have distinct oscillatory zoning, highest U and Th contents, and Na-free, Mg-rich mineral inclusions, and thus indicate an igneous (formation of oceanic crust) or hydrothermal (serpentinization and/or rodingitization) event in the Middle Jurassic. Group-II zircons, with a mean age of 146.5 ± 3.4 Ma, have bright luminescence without oscillatory zoning and include jadeite and jadeitic pyroxene inclusions, suggesting that formation of the Myanmar jadeitites, as well as subduction of the eastern Indian oceanic plate, occurred in the Late Jurassic. Group-III zircons have an age of 122.2 ± 4.8 Ma, which represents a later unknown thermal event. Discovery of the Middle Jurassic zircons provides geochronological constraint on the tectonic evolution of the eastern Indo-Burman Range.
Pliocene–Pleistocene HT–LP metamorphism during multiple granitic intrusions in the southern branch of the Larderello geothermal field (southern Tuscany, Italy)
Authors: Rossetti F. , Balsamo F. , Villa I.M. , Bouybaouenne M. , Faccenna C. , Funiciello R.
Published: January 2008

This work presents the results of a multidiscipinary study carried out in the southern branch of the Larderello geothermal field (Travale–Montieri area), which was based on the integration of field data with information on the deeper structures as derived from interpretation of seismic reflection profiles and the
P
–
T
–
t
history of the metamorphic substratum as reconstructed from borehole data. Our data document that the structural and metamorphic signature of the metamorphic substratum is chiefly related to a prograde HT–LP metamorphic overprint, ranging in age from
c
. 2.8 to 0.7 Ma. The metamorphic climax was attained within the K-feldspar zone and equilibrated at
P
–
T
conditions of about 0.2 GPa and 650 °C. We interpret these new findings as evidence of Pliocene–Pleistocene thermal metamorphism associated with multiple granite intrusions at shallow levels in the crust. These results (1) add strength to the interpretations emphasizing the contribution of Neogene thermal metamorphism to the tectonometamorphic signature of the basement rocks found at depth in the Larderello geothermal field, and (2) provide insights on the thermal structures of the crustal section hosting the geothermal field and on the modes through which the long-lived positive thermal anomaly operated in southern Tuscany.
Timing, slip rate, displacement and cooling history of the Mykonos detachment footwall, Cyclades, Greece, and implications for the opening of the Aegean Sea basin
Authors: Brichau Stéphanie , Ring Uwe , Carter Andrew , Bolhar Robert , Monié Patrick , Stockli Daniel , Brunel Maurice
Published: January 2008

We constrain the slip and cooling history of the Mykonos detachment footwall using thermochronometry. A U–Pb zircon age of 13.5 ± 0.3 Ma dates intrusion of the Mykonos monzogranite.
40
Ar/
39
Ar hornblende and biotite ages from the monzogranite are 12.7 ± 0.6 Ma and 10.9 ± 0.6 Ma, whereas zircon and apatite fission-track ages range from 13 ± 0.8 Ma to 10.7 ± 0.8 Ma and 12.5 ± 2.2 Ma to 10.5 ± 1.8 Ma. (U–Th)/He ages range from 13.6 ± 0.6 Ma to 9.0 ± 0.7 Ma for zircon and 11.1 ± 0.5 Ma to 8.9 ± 0.4 Ma for apatite. The ages in part overlap within 2σ errors and together with the long apatite fission-track lengths (>14 μm) support rapid cooling at rates >100 °C Ma
−1
. The low-temperature thermochronometric ages decrease east-northeastwards in the direction of hanging-wall transport on the Mykonos detachment. Age–distance relationships show that the Mykonos detachment slipped at an average rate of 6.0 +9.2/−2.4 km Ma
−1
causing
c
. 30 km of offset and
c
. 12 km of exhumation. This result indicates that Miocene low-angle normal faulting was not important for the exhumation of the Cycladic blueschist unit. The opening of the Aegean Sea basin in the Miocene was controlled by a few large-magnitude low-angle normal faults.
Provenance of microcrystalline carbonate cement in limestone–marl alternations (LMA): aragonite mud or molluscs?
Authors: WHEELEY JAMES R. , CHERNS LESLEY , WRIGHT V.PAUL
Published: January 2008

Aragonite derived from marine molluscs is evaluated as the source for microcrystalline carbonate cements of limestone–marl alternations (LMA). Calculations demonstrate that extremely low levels of mollusc-derived aragonite, well below the production rates of molluscs in modern marine settings, could have provided sufficient carbonate to cement examples of Ordovician, Silurian and Jurassic LMA in non-tropical or tropical settings. It is likely that even in the Palaeozoic molluscs provided sufficient carbonate entirely to source microcrystalline cements of LMA. Autochthonous molluscan aragonite is the only viable aragonite precursor for LMA microcrystalline cements of cool-water settings where temperatures precluded calcified algae and abiotic carbonate precipitation. In ‘calcite seas’ where Mg:Ca ratios inhibited both abiogenic aragonite precipitation and aragonite generation by calcified algae, molluscan aragonite was again the most likely main contributor. In some epeiric seas where brackish wedges switched off the shallow-water carbonate mud factories molluscan aragonite is the parsimonious source of carbonate for LMA microcrystalline cements.