bluuebunny/crossref_metadata_2025 huggingface dataset:
Two-photon-induced three-dimensional optical data storage in CdS quantum-dot doped photopolymer
Authors: Li Xiangping , Bullen Craig , Chon James W. M. , Evans Richard A. , Gu Min
Published: April 2007

The authors demonstrate three-dimensional erasable bit optical data storage in a quantum-dot doped photopolymer under two-photon excitation by a near-infrared femtosecond pulsed laser beam. It is shown that the photorefractive polymer consisting of poly(vinyl carbazole), ethyl carbazole, 4-(diethylaminobenzylidene)-malononitrile, and CdS quantum dots exhibits the changes not only in refractive index but also in fluorescence. Such a photosensitivity provides a multimode readout mechanism. In particular, the use of S rich surface quantum dots not only allows the two-photon-induced bit optical data storage with greater contrast but also expands the margin between permanent and erasable recording thresholds.
Tunable ferroelectric photonic crystals based on porous silicon templates infiltrated by sodium nitrite
Authors: Murzina Tatyana V. , Sychev Fedor Yu. , Kolmychek Irina A. , Aktsipetrov Oleg A.
Published: April 2007

Ferroelectric photonic band-gap (PBG) structures are fabricated by the infiltration of sodium nitrite into the nanoporous silicon templates composed by the electrochemical etching of n-type silicon. Reversible spectral tuning of the PBG and of the microcavity mode up to 15nm is attained in the temperature interval from 50to165°C due to the temperature changes of the refractive index of sodium nitrite in nanoporous silicon matrix. Optical second-harmonic generation measurements prove the ferroelectric state of the composed nanocomposite PBG structures.
33.7
MHz
heavy-ion radio frequency quadrupole linac at VECC Kolkata
Authors: Chakrabarti Alok , Naik Vaishali , Dechoudhury Siddhartha , Bandyopadhyay Arup , Mondal Manas , Pandey Hemendra Kumar , Roy Tapatee Kundu , Sanyal Dirtha , Bhowmick Debasis
Published: April 2007

A 33.7MHz heavy-ion radio frequency quadrupole (RFQ) linear accelerator has been designed, built, and tested. It is a four-rod-type RFQ designed for acceleration of 1.38keV∕u, q∕A⩾1∕16 ions to about 29keV∕u. Transmission efficiencies of about 85% and 80% have been measured for the unanalyzed and analyzed beams, respectively, of oxygen (O2+16, O3+16, O4+16), nitrogen (N3+14, N4+14), and argon (Ar4+40). The system design and measurements along with results of beam acceleration test will be presented.
Vacuolar acidity, protein profile, and crystal composition of epidermal bladder cells of the halophyte Mesembryanthemum crystallinum
Authors: Jou Yingtzy , Wang Ya-Ling , Yen Hungchen Emilie
Published: April 2007

The halophyte Mesembryanthemum crytallinum L. (ice plant) is marked by giant epidermal bladder cells (EBC). The differentiation of pavement cells into EBC occurs at an early developmental stage. EBC occupy most of the surface area in the aerial parts of salt-stressed mature ice plants. A large vacuolar reservoir for ion and water storage plays an important role in salinity adaptation. To monitor the acidity of the vacuole at different developmental stages of EBC, peels from the abaxial surface were stained with a pH-sensitive dye, neutral red (NR). Presence of both NR-stained (acidic) and NR-unstained (neutral) EBC were found at the juvenile stage in ice plants. Continuous exposure to illumination decreased the acidity of the NR-stained cells. The EBC protein profile illustrated the prominent co-existence of highly acidic and basic proteins in these specialised cells. Major proteins that accumulate in EBC are involved in photosynthesis, sodium compartmentalisation, and defence. Numerous raphide crystals were found in well fertilised ice plants. Salt-stressed cells exhibited changes in the surface charge and element composition of raphide crystals. A disappearance of potassium in the high-salt grown crystals suggests that these crystals might serve as a potassium reservoir to maintain the Na+/K+ homeostasis in this halophyte.
MHC class II deprivation impairs CD4 T cell motility and responsiveness to antigen-bearing dendritic cells
in vivo
Authors: Fischer Ursula B. , Jacovetty Erica L. , Medeiros Ricardo B. , Goudy Brian D. , Zell Traci , Swanson Jeannie-Beth , Lorenz Elizabeth , Shimizu Yoji , Miller Mark J. , Khoruts Alexander , Ingulli Elizabeth
Published: April 2007

The role continuous contact with self-peptide/MHC molecules (self ligands) in the periphery plays in the function of mature T cells remains unclear. Here, we elucidate a role for MHC class II molecules in T cell trafficking and antigen responsiveness
in vivo
. We find that naïve CD4 T cells deprived of MHC class II molecules demonstrate a progressive and profound defect in motility (measured by real-time two-photon imaging) and that these cells have a decreased ability to interact with limiting numbers of cognate antigen-bearing dendritic cells, but they do not demonstrate a defect in their responsiveness to direct stimulation with anti-CD3 monoclonal antibody. Using GST fusion proteins, we show that MHC class II availability promotes basal activation of Rap1 and Rac1 but does not alter the basal activity of Ras. We propose that tonic T cell receptor signaling from self-ligand stimulation is required to maintain a basal state of activation of small guanosine triphosphatases critical for normal T cell motility and that T cell motility is critical for the antigen receptivity of naïve CD4 T cells. These studies suggest a role for continuous self-ligand stimulation in the periphery for the maintenance and function of mature naïve CD4 T cells.
C–C σ complexes of rhodium
Authors: Brayshaw Simon K. , Sceats Emma L. , Green Jennifer C. , Weller Andrew S.
Published: April 2007

In this article, the complexes [Rh(Binor-S′)(PR3)][BAr4F] (R =iPr, Cy, C5H9) are described. A combination of x-ray crystallography, NMR spectroscopy, density functional theory, and “atoms in molecules” calculations unequivocally demonstrates that the complexes contain rare examples of metal···CC agostic interactions. Moreover, they are fluxional on the NMR time scale, undergoing rapid and reversible CC activation. Kinetic data and calculations point to a bismetallacyclobutane, Rh(V), intermediate.
Self-organization of actin filament orientation in the dendritic-nucleation/array-treadmilling model
Authors: Schaus Thomas E. , Taylor Edwin W. , Borisy Gary G.
Published: April 2007

The dendritic-nucleation/array-treadmilling model provides a conceptual framework for the generation of the actin network driving motile cells. We have incorporated it into a 2D, stochastic computer model to study lamellipodia via the self-organization of filament orientation patterns. Essential dendritic-nucleation submodels were incorporated, including discretized actin monomer diffusion, Monte-Carlo filament kinetics, and flexible filament and plasma membrane mechanics. Model parameters were estimated from the literature and simulation, providing values for the extent of the leading edge-branching/capping-protective zone (5.4 nm) and the autocatalytic branch rate (0.43/sec). For a given set of parameters, the system evolved to a steady-state filament count and velocity, at which total branching and capping rates were equal only for specific orientations; net capping eliminated others. The standard parameter set evoked a sharp preference for the ±35 degree filaments seen in lamellipodial electron micrographs, requiring ≈12 generations of successive branching to adapt to a 15 degree change in protrusion direction. This pattern was robust with respect to membrane surface and bending energies and to actin concentrations but required protection from capping at the leading edge and branching angles >60 degrees. A +70/0/−70 degree pattern was formed with flexible filaments ≈100 nm or longer and with velocities <≈20% of free polymerization rates.
International Competitiveness and Technological Change
Authors: Miozzo Marcela , Walsh Vivien
Published: April 2007

This book analyses the role of technological change in the competitiveness of firms and national economies. This includes an examination of the roles of R&D spending, and the organizational and technological capabilities of firms in the encouragement of innovation; the way institutions in various nations differ in the way in which they encourage, or discourage, innovation; and the way in which different industrial sectors provide, or fail to provide, incentives to innovate; and the ways in which trade, the operation of multinationals and international trade negotiations influence national production and innovation systems. The book explores the relation between organizational structures, and the process of innovation. It places the analysis of innovation within an international perspective and gives historical and current examples of the interaction between organizational and technological capabilities, industrial and innovation policies and economic performance. Examples are drawn from a range of sectors (services, pharmaceuticals, construction, chemicals) and a range of countries (including the UK and other European countries, the USA, East Asia, and Latin America).
Cochlear Implantation in Cockayne Syndrome: Our Experience of Two Cases With Different Outcomes
Authors: Morris David P. , Alian Wael , Maessen Heather , Creaser Cathy , Demmons‐O'Brien Stephanie , Van Wijhe Rene , Bance Manohar
Published: April 2007

Cockayne syndrome is a rare autosomal recessive defect in DNA repair resulting in a classic facies with potential visual and auditory impairment. The hearing loss begins peripherally and may become central as the condition progresses. Coexisting sensory deprivation from visual impairment and the possibility of progressive deterioration in mental function conspire with a lack of published experience to produce many challenges for the cochlear implant team. To the best of our knowledge, we present the first case reports with documented follow‐up of cochlear implantation in two patients with different manifestations of Cockayne syndrome.
Giant Fibrovascular Polyp of the Esophagus Causing Sudden Dyspnea: Endoscopic Treatment
Authors: Alobid Isam , Vilaseca Isabel , Fernández Jose , Bordas Josep María
Published: April 2007

A 76‐year‐old man with sudden dyspnea was admitted to our department. A fleshy mass was visualized in the labial commissure, and the flexible esophagoscopy showed the polyp prolapsed into the oropharynx, partially obstructing the airway. The polyp was encircled with a large oval snare and Endoloop, which was adjusted to stalk‐basis before tightening. Pure coagulation was used to transect the lesion, which was then retrieved. The polyp measured 10 × 2.5 cm. To our knowledge, our case is the first large esophageal giant fibrovascular polyps causing sudden dyspnea in the literature that has been resected endoscopically without complications.
Factors That Influence Treatment Decision in Older Patients With Resectable Head and Neck Cancer
Authors: Sanabria Alvaro , Carvalho André Lopes , Vartanian José Guilherme , Magrin José , Ikeda Mauro Kasuo , Kowalski Luiz Paulo
Published: April 2007

Objectives: To find clinical factors related to administration of substandard treatment in older patients with head and neck cancer.

Study Design: Historic cohort.

Methods: Patients of 70 years of age of older with diagnosis of resectable head and neck cancer were included. Treatment offered to patients was classified as standard or substandard by experienced surgeons. Relation of age, clinical stage, comorbidities, performance status, and treatment with substandard treatment was explored. The effect of substandard treatment on survival was assessed.

Results: Three hundred twelve patients were included. Substandard treatment was offered to 19.9% of patients. Associated factors related to selection of substandard treatment were higher age, oro/hypopharynx tumor site, severe comorbidity, advanced clinical stage, and low Karnofsky Index. Patients submitted to substandard treatment had lower overall and cancer‐specific survival (45.9% vs. 19.9% and 63.0% vs. 33.1%, respectively).

Conclusion: Selection of substandard treatment decreases overall and cancer‐specific survival. Selecting substandard treatment for reasons such as chronologic age, tumor site, or moderate or mild comorbidities worsen patient prognosis.
Solitary Parathyroid Adenoma: A Rare Cause of Primary Hyperparathyroidism in Children
Authors: Venail Frederic , Nicollas Richard , Morin Denis , Mackle Tara , Garnier J M. , Triglia Jean‐Michel , Mondain Michel
Published: April 2007

Solitary parathyroid adenoma is a rare cause of primary hyperparathyroidism in children. We report the cases of four children, aged 7 to 14 years old, who presented with a variety of symptoms (growth retardation, glomerulonephritis, pathological fracture, mood swings). Diagnosis was based on clinical examination, imaging, and biochemical analysis. Treatment consisted of surgical excision of the adenoma. As diagnosis was delayed in all four patients, we recommend systematically checking serum calcium levels in children with certain nonspecific symptoms. Adenoma resection usually restores normal serum calcium levels and, hence, avoids further complications.
Racial Differences in Stage and Survival in Head and Neck Squamous Cell Carcinoma
Authors: Nichols Anthony C. , Bhattacharyya Neil
Published: April 2007

Objectives: The goal of this study was to characterize differences in survival between black patients and white patients with squamous cell carcinoma of the head and neck (HNSCCA).

Design: Cases of oral tongue and glottic SCCA in black patients or white patients were extracted from the Surveillance, Epidemiology, and End Results (SEER) database (years 1988–2002). For each primary site, TNM staging was imputed, and staging distributions were compared between races. For each black patient, a randomly selected white control was matched for age at diagnosis, sex, stage, surgical treatment, and radiation. Kaplan‐Meier survival comparisons for both overall and disease‐specific survival were then conducted for the matched pairs.

Results: From 1,919 cases of carcinoma of the oral tongue, those of 151 black and 1,768 white patients were extracted. Black patients had a significantly elevated T stage (P = .001) and N stage (P = .002) at primary presentation. Of glottic carcinoma, 4,578 cases (625 black and 3,953 white patients) were extracted. Black patients again presented with significantly elevated T stage (P < .001) and N stage (P < .001) compared with white patients. For 43 matched pairs with tongue carcinoma, mean overall survival for black patients was 66.1 months versus 74.8 months for matched white controls (P = .502, log‐rank test). Disease‐specific survival was 91.1 months for black patients versus 109.6 months for white patients (P = .168). For 401 matched pairs with glottic carcinoma, mean overall survival for black patients was 96.6 months versus 114.5 months for white controls (P < .001). Similarly, the mean disease‐specific survival was 149.4 months for black patients versus 167.1 months for white patients (P < .001)

Conclusion: Controlling for stage and treatment, black patients demonstrate poorer overall and disease‐specific survival with SCCA, implying other intrinsic or extrinsic factors influencing survival.
Use of a Novel Ultrasonic Surgical System for Decompression of the Facial Nerve
Authors: Samy Ravi N. , Krishnamoorthy Kumaresh , Pensak Myles L.
Published: April 2007

Objective: The middle cranial fossa approach has been used to explore and decompress the facial nerve in patients with Bell's palsy and facial nerve tumors. Unfortunately, this approach is technically challenging and has a significant risk of injury to the facial nerve and to the cochleovestibular organs. One way to minimize the risk may be with the use of the Sonopet Omni ultrasonic aspirator (Synergetics Inc., St Charles, MO) instead of an otologic drill.

Methods: In this prospective study using cadaveric temporal bones, a total of 17 temporal bone specimens were used. Seven cadaveric temporal bones were used (4‐left, 3‐right) for the initial feasibility study. At a second session, an additional 10 temporal bones (5‐left, 5‐right) underwent decompression of the facial nerve from the fundus of the internal auditory canal (IAC) to the geniculate ganglion (ie, labyrinthine segment). The average time to decompress the labyrinthine segment was measured. The temporal bones were then examined for evidence of any injury.

Results: None of the 17 temporal bones showed any sign of injury to the superior semicircular canal or the cochlea. However, one specimen did have penetration of the IAC dura; another specimen did have penetration of the epineurium of the facial nerve. However, in neither case was there any evidence of injury to the facial nerve itself. At the first session, the average time for decompression of the labyrinthine segment was 10 minutes and 12 seconds. At the second session, the average time for decompression was 5 minutes and 0 seconds.

Conclusion: The ultrasonic surgical system may be used as an alternative to the surgical drill for decompression of the facial nerve. Although a learning curve does exist, as with any new surgical tool or device, our results indicate that the device can be used safely and in a reasonable amount of time. However, before proceeding with intraoperative use of this device for otologic and neurotologic procedures, familiarization is first recommended on cadaveric temporal bone specimens.
Biochemical Results of Reoperations for Medullary Thyroid Carcinoma
Authors: Vila Juan Manuel Fernandez , Peix Jean L. , Mandry Alexandra C. , Mezzadri Norberto A. , Lifante Jean C.
Published: April 2007

Background: The calcitonin is a sensitive marker for the presence of medullary thyroid carcinoma, therefore, invaluable in the follow‐up of patients who have been treated. Biological cure of the medullary thyroid cancer refers to a basal plasma calcitonin of less than 10 ng/l without elevation after stimulation tests.

Study Design: Biochemical results of reoperations for medullary thyroid carcinoma were reviewed from a series of 35 patients who underwent 47 reinterventions.

Results: The indications for reoperation were: hypercalcitoninemia with clinical evidence of the disease (32 cases); hypercalcitoninemia after an inadequate primary surgery (6 cases); persistent hypercalcitoninemia with biochemical evidence of the disease (2 cases); liver metastases (1 case); and palliative surgery for relieving symptoms (1 case). Only three patients of the series had biochemical cure after reoperation (patients with an inadequate primary surgery).

Conclusions: This study is consistent with the bibliographic reviews supporting that the cervical reoperation, eventually mediastinal, for residual hypercalcitoninemia after primary surgical treatment is indicated when the initial intervention did not follow the French Calcitonin Tumour Study Group (GETC) recommendations or when a specific lesion is evidenced by imaging studies without systemic dissemination.
Mandibular Subluxation for Distal Cervical Exposure of the Internal Carotid Artery
Authors: Fortes Felipe S. G. , da Silva Erasmo Simão , Sennes Luiz Ubirajara
Published: April 2007

Introduction: Surgical access to the distal segment of the cervical internal carotid artery (ICA) is a challenge because of the limited exposure imposed by bony structures and concern regarding cranial nerve and major vasculature injury. Our objective is to quantify the additional exposure of the distal cervical ICA obtained with mandibular subluxation (MS) compared with maneuvers that do not mobilize the mandible.

Methods: Thirty dissections of the cervical ICA and common carotid artery bifurcation were performed on fresh cadavers. The length of the ICA exposure was measured from the carotid bifurcation to the most distally exposed ICA after sectioning the posterior belly of the digastric and stylohyoid muscles, removal of the styloid process, and MS.

Results: After MS, a 5.52 ± 1.00 cm mean exposure of the cervical ICA was obtained. Comparison between the second and third measures revealed an average additional exposure of the ICA of 0.77 cm, corresponding to an additional 16.2% (P < .001). Neck length, sex, and age showed no correlation with the ICA exposure.

Conclusion: MS provided an additional exposure of the distal segment of the cervical ICA and may be useful in selected cases to improve access. However, staged maneuvers should be used, and the need for MS depends on the level and extension of the lesion.
Prognostic Significance of the MUC1 and MUC4 Expressions in Thyroid Papillary Carcinoma
Authors: Baek Seung‐Kuk , Woo Jeong‐Soo , Kwon Soon‐Young , Lee Sang‐Hag , Chae Yang‐Seok , Jung Kwang‐Yoon
Published: April 2007

Objectives: The aim of the present study was to examine the expressions of mucin genes MUC1 and MUC4 and to evaluate the difference of their expressions in normal thyroid tissue, follicular adenoma, and papillary carcinoma. Furthermore, we aimed to estimate their prognostic significance in papillary carcinoma.

Methods: We performed semiquantitative reverse‐transcription polymerase chain reaction for determining the MUC1 and MUC4 mRNA expressions, and immunohistochemical staining was performed to determine the MUC1 and MUC4 protein expressions in 22 normal thyroid tissues, 22 follicular adenomas, and 15 papillary carcinomas. The semiquantitative scoring of the immunohistochemical staining was compared with the prognostic factors for thyroid carcinoma to evaluate the prognostic significance in 87 papillary carcinoma patients.

Results: The MUC1 mRNA of the papillary carcinoma tissue showed an increased expression level compared with the other tissues. However, the expression level of MUC4 mRNA was weak in all the specimens, and this was not significantly different among the three groups. MUC1 immunoreactivity was more intense in papillary carcinoma but not in the other tissues. MUC4 was not expressed in all thyroid tissues. The expression of MUC1 was significantly associated with tumor size, extrathyroidal spread, and TNM stage (P < .05).

Conclusions: Up‐regulation of MUC1 may play a more important role than that of MUC4 in the development of thyroid papillary carcinoma, and it may have some significance as a prognostic factor.
Injection of Autologous Muscle Stem Cells (Myoblasts) for the Treatment of Vocal Fold Paralysis: A Pilot Study
Authors: Halum Stacey L. , Naidu Moumita , Delo Dawn M. , Atala Anthony , Hingtgen Cynthia M.
Published: April 2007

Objective: Autologous muscle stem cell (myoblast) therapy may be an ideal treatment for vocal fold paralysis because of its technical ease (administered by injection), its potential to restore muscular defects and dynamic function, and its autologous origin. The goal of this project was to determine whether autologous myoblast injection into the thyroarytenoid (TA) muscle after recurrent laryngeal nerve (RLN) injury could attenuate TA muscle atrophy and enhance spontaneous reinnervation.

Study Design: This was an animal experiment.

Methods: Unilateral RLN transection and sternocleidomastoid muscle (approximately 1 g) biopsies were performed in 16 male Wistar rats. Biopsies were used to create myoblast cultures for each animal. One month later, 106 autologous myoblasts labeled with fluorescent cell membrane marker (PKH26) were injected into the denervated TA of each study animal, with saline injected into controls. Animals were euthanized at 2 weeks and 2 months after myoblast injection. Outcomes included myoblast survival, TA fiber diameter and volume, and reinnervation status (motor endplate to nerve contact staining).

Results: All denervated TA study specimens demonstrated viable myoblasts under fluorescent microscopy, with the myoblasts demonstrating fusion with the TA myofibers at 2 months. The myoblast‐treated group had greater mean TA fiber diameter than denervated TA controls at 2 months (25.1 vs. 21.1 μm; P = .04) but not at 2 weeks (25.7 μm vs. 23.5 μm; P = .06). Mean TA volumes were greater in the myoblast‐treated groups at both time points. Two of the animals in the myoblast‐treated group demonstrated adductor motion at 2 months, whereas none of the 2 week study animals or controls recovered adduction. Reinnervation was not significantly different between the myoblast‐treated groups and the denervated controls.

Conclusions: Autologous myoblast therapy may be a future treatment for vocal fold paralysis, with current findings demonstrating myoblast survival with attenuation of TA muscle atrophy.
Orangutans use compliant branches to lower the energetic cost of locomotion
Authors: Thorpe S.K.S , Crompton R.H , Alexander R.McN
Published: April 2007

Within the forest canopy, the shortest gaps between tree crowns lie between slender terminal branches. While the compliance of these supports has previously been shown to increase the energetic cost of gap crossing in arboreal animals (e.g. Alexander 1991Z. Morphol. Anthropol.78, 315–320; Demeset al. 1995Am. J. Phys. Anthropol.96, 419–429), field observations suggest that some primates may be able to use support compliance to increase the energetic efficiency of locomotion. Here, we calculate the energetic cost of alternative methods of gap crossing in orangutans (Pongo abelii). Tree sway (in which orangutans oscillate a compliant tree trunk with increasing magnitude to bridge a gap) was found to be less than half as costly as jumping, and an order of magnitude less costly than descending the tree, walking to the vine and climbing it. Observations of wild orangutans suggest that they actually use support compliance in many aspects of their locomotor behaviour. This study seems to be the first to show that elastic compliance in arboreal supports can be used to reduce the energetic cost of gap crossing.
Survival against the odds: ontogenetic changes in selective pressure mediate growth-mortality trade-offs in a marine fish
Authors: Gagliano Monica , McCormick Mark I , Meekan Mark G
Published: April 2007

For organisms with complex life cycles, variation among individuals in traits associated with survival in one life-history stage can strongly affect the performance in subsequent stages with important repercussions on population dynamics. To identify which individual attributes are the most influential in determining patterns of survival in a cohort of reef fish, we compared the characteristics of
Pomacentrus amboinensis
surviving early juvenile stages on the reef with those of the cohort from which they originated. Individuals were collected at hatching, the end of the planktonic phase, and two, three, four, six and eight weeks post-settlement. Information stored in the otoliths of individual fish revealed strong carry-over effects of larval condition at hatching on juvenile survival, weeks after settlement (i.e. smaller-is-better). Among the traits examined, planktonic growth history was, by far, the most influential and long-lasting trait associated with juvenile persistence in reef habitats. However, otolith increments suggested that larval growth rate may not be maintained during early juvenile life, when selective mortality swiftly reverses its direction. These changes in selective pressure may mediate growth-mortality trade-offs between predation and starvation risks during early juvenile life. Ontogenetic changes in the shape of selectivity may be a mechanism maintaining phenotypic variation in growth rate and size within a population.
The parasitic chytrid,Zygorhizidium, facilitates the growth of the cladoceran zooplankter,Daphnia, in cultures of the inedible alga,Asterionella
Authors: Kagami Maiko , von Elert Eric , Ibelings Bas W , de Bruin Arnout , Van Donk Ellen
Published: April 2007

In food-web studies, parasites are often ignored owing to their insignificant biomass. We provide evidence that parasites may affect trophic transfer in aquatic food webs. Many phytoplankton species are susceptible to parasitic fungi (chytrids). Chytrid infections of diatoms in lakes may reach epidemic proportions during diatom spring blooms, so that numerous free-swimming fungal zoospores (2–3 μm in diameter) are produced. Analysis shows that these zoospores are rich in polyunsaturated fatty acids and sterols (particularly cholesterol), which indicates that they provide excellent food for zooplankters such asDaphnia. In life-table experiments using the large diatomAsterionella formosaas food,Daphniagrowth increased significantly in treatments where a parasite was present. By grazing on the zoospores,Daphniaacquired important supplementary nutrients and were able to grow. When large inedible algae are infected by parasites, nutrients within the algal cells are consumed by these chytrids, some of which, in turn, are grazed byDaphnia. Thus, chytrids transfer energy and nutrients from their hosts to zooplankton. This study suggests that parasitic fungi alter trophic relationships in freshwater ecosystems and may be the important components in shaping the community and the food-web dynamics of lakes.
The Acropetal Wave of Developmental Cell Death of Tobacco Corolla Is Preceded by Activation of Transglutaminase in Different Cell Compartments
Authors: Della Mea Massimiliano , De Filippis Francesca , Genovesi Valeria , Serafini Fracassini Donatella , Del Duca Stefano
Published: April 2007

The activity of transglutaminase (TGase), an enzyme responsible for polyamine conjugation to proteins, was analyzed in relationship to developmental cell death (DCD) during the flower life span stages of the tobacco (Nicotiana tabacum) corolla. As the DCD exhibits an acropetal gradient, TGase was studied in corolla proximal, medial, and distal parts. TGase was immunorecognized by three TGase antibodies; the main 58-kD band decreased during corolla life, whereas a 38-kD band localized progressively from basal to distal parts. The former was present in the soluble, microsomal, plastidial (together with the 38-kD band), and cell wall fractions. The endogenous TGase activity increased during DCD reaching a maximum soon after the corolla opening. The activity maximum shifted from proximal to distal part, preceding the DCD acropetal pattern. A similar activity increase was observed by the exogenous TGase substrate (histidine6-Xpr-green fluorescent protein). Subcellular activities were detected in (1) the microsomes, where TGase activity is in general higher in the proximal part, peaking at the corolla opening; (2) the soluble fraction, where it is present only in the proximal part at senescence; (3) the plastids, where it shows an increasing trend; and (4) cell walls, prevailing in the distal part and progressively increasing. These data suggest a relationship between DCD and TGase; the latter, possibly released in the cell wall through the Golgi vesicles, could cooperate to cell wall strengthening, especially at the abscission zone and possibly during corolla shape change. The plastid TGase, stabilizing the photosystems, could sustain the energy requirements for the senescence progression.
Arabidopsis Inositol Polyphosphate 6-/3-Kinase (AtIpk2β) Is Involved in Axillary Shoot Branching via Auxin Signaling
Authors: Zhang Zai-Bao , Yang Guang , Arana Fernando , Chen Zhen , Li Yan , Xia Hui-Jun
Published: April 2007

The Arabidopsis (Arabidopsis thaliana) inositol polyphosphate 6-/3-kinase gene (AtIpk2β) is known to participate in inositol phosphate metabolism. However, little is known about its physiological functions in higher plants. Here, we report that AtIpk2β regulates Arabidopsis axillary shoot branching. By overexpressing AtIpk2β in the wild type and mutants, we found that overexpression of AtIpk2β leads to more axillary shoot branches. Further analysis of AtIpk2β overexpression lines showed that axillary meristem forms earlier and the bud outgrowth rate is also accelerated, resulting in more axillary shoot branches. The AtIpk2β promoter/β-glucuronidase (GUS) fusion (AtIpk2β∷GUS) expression pattern is similar to that of the auxin reporter DR5∷GUS. Moreover, AtIpk2β can be induced in response to exogenous indole-3-acetic acid (IAA) treatments. In addition, AtIpk2β overexpression plants exhibit IAA-related phenotypes and are more resistant to exogenous IAA treatments. Further analysis employing reverse transcription-polymerase chain reaction shows that some genes, including auxin-biosynthesis (CYP83B1), auxin-transport (PIN4), and auxin-mediated branching genes (MAX4 and SPS), are regulated by AtIpk2β. Taken together, our data provide insights into a role for AtIpk2β in axillary shoot branching through the auxin signaling pathway.
The Structure of Two N-Methyltransferases from the Caffeine Biosynthetic Pathway
Authors: McCarthy Andrew A. , McCarthy James G.
Published: April 2007

Caffeine (1,3,7-trimethylxanthine) is a secondary metabolite produced by certain plant species and an important component of coffee (Coffea arabica and Coffea canephora) and tea (Camellia sinensis). Here we describe the structures of two S-adenosyl-l-methionine-dependent N-methyltransferases that mediate caffeine biosynthesis in C. canephora ‘robusta’, xanthosine (XR) methyltransferase (XMT), and 1,7-dimethylxanthine methyltransferase (DXMT). Both were cocrystallized with the demethylated cofactor, S-adenosyl-l-cysteine, and substrate, either xanthosine or theobromine. Our structures reveal several elements that appear critical for substrate selectivity. Serine-316 in XMT appears central to the recognition of XR. Likewise, a change from glutamine-161 in XMT to histidine-160 in DXMT is likely to have catalytic consequences. A phenylalanine-266 to isoleucine-266 change in DXMT is also likely to be crucial for the discrimination between mono and dimethyl transferases in coffee. These key residues are probably functionally important and will guide future studies with implications for the biosynthesis of caffeine and its derivatives in plants.
Apyrases (Nucleoside Triphosphate-Diphosphohydrolases) Play a Key Role in Growth Control in Arabidopsis
Authors: Wu Jian , Steinebrunner Iris , Sun Yu , Butterfield Timothy , Torres Jonathan , Arnold David , Gonzalez Antonio , Jacob Francis , Reichler Stuart , Roux Stanley J.
Published: April 2007

Expression of two Arabidopsis (Arabidopsis thaliana) apyrase (nucleoside triphosphate-diphosphohydrolase) genes with high similarity, APY1 and APY2, was analyzed during seedling development and under different light treatments using β-glucuronidase fusion constructs with the promoters of both genes. As evaluated by β-glucuronidase staining and independently confirmed by other methods, the highest expression of both apyrases was in rapidly growing tissues and/or tissues that accumulate high auxin levels. Red-light treatment of etiolated seedlings suppressed the protein and message level of both apyrases at least as rapidly as it inhibited hypocotyl growth. Adult apy1 and apy2 single mutants had near-normal growth, but apy1apy2 double-knockout plants were dwarf, due primarily to reduced cell elongation. Pollen tubes and etiolated hypocotyls overexpressing an apyrase had faster growth rates than wild-type plants. Growing pollen tubes released ATP into the growth medium and suppression of apyrase activity by antiapyrase antibodies or by inhibitors simultaneously increased medium ATP levels and inhibited pollen tube growth. These results imply that APY1 and APY2, like their homologs in animals, act to reduce the concentration of extracellular nucleotides, and that this function is important for the regulation of growth in Arabidopsis.
The Nuclear-Encoded Factor HCF173 Is Involved in the Initiation of Translation of the psbA mRNA in Arabidopsis thaliana
Authors: Schult Kerstin , Meierhoff Karin , Paradies Susanne , Töller Thomas , Wolff Petra , Westhoff Peter
Published: April 2007

To gain insight into the biogenesis of photosystem II (PSII) and to identify auxiliary factors required for this process, we characterized the mutant hcf173 of Arabidopsis thaliana. The mutant shows a high chlorophyll fluorescence phenotype (hcf) and is severely affected in the accumulation of PSII subunits. In vivo labeling experiments revealed a drastically decreased synthesis of the reaction center protein D1. Polysome association experiments suggest that this is primarily caused by reduced translation initiation of the corresponding psbA mRNA. Comparison of mRNA steady state levels indicated that the psbA mRNA is significantly reduced in hcf173. Furthermore, the determination of the psbA mRNA half-life revealed an impaired RNA stability. The HCF173 gene was identified by map-based cloning, and its identity was confirmed by complementation of the hcf phenotype. HCF173 encodes a protein with weak similarities to the superfamily of the short-chain dehydrogenases/reductases. The protein HCF173 is localized in the chloroplast, where it is mainly associated with the membrane system and is part of a higher molecular weight complex. Affinity chromatography of an HCF173 fusion protein uncovered the psbA mRNA as a component of this complex.
The effect of cricoid pressure on intubation facilitated by the gum elastic bougie*
Authors: McNelis U. , Syndercombe A. , Harper I. , Duggan J.
Published: April 2007

Summary Tracheal tube impingement is common during gum elastic bougie facilitated intubation and a 90° anti‐clockwise rotation of the tube usually relieves it. We detail a case where this manoeuvre failed in the presence of cricoid pressure. We investigated the effect of cricoid pressure on gum elastic bougie facilitated intubation in 120 patients randomly allocated to receive sham cricoid pressure (n = 60) or 30 N cricoid pressure (n = 60). Impingement occurred in 23/60 (38%) with sham cricoid pressure and 36/60 (60%) with 30 N cricoid pressure (p < 0.025). Only females showed an increase in impingement with cricoid pressure: 29% sham cricoid pressure vs 63% 30 N cricoid pressure, p < 0.01, whereas the impingement in males was ∼ 60% in both groups. Ninety degree anti‐clockwise rotation of the tube was successful in all 23 patients (100%) with sham cricoid pressure and in 32/36 patients (89%) with 30 N cricoid pressure. Releasing cricoid pressure relieved the obstruction in the four cases where 90° anti‐clockwise rotation of the tube failed. Impingement is common and 90° anti‐clockwise rotation is highly effective in both the presence and absence of cricoid pressure. In a small number of cases, cricoid pressure may cause the manoeuvre to fail.
Lead miners' soughs in Derbyshire
Authors: Ford Trevor D. , Rieuwerts Jim
Published: April 2007

Long before the science of geology was established, the Derbyshire lead miners used elementary practical geology in laying out the lines of their soughs, or drainage levels, to gain any possible advantage of easier excavation. Their objective was to lower the water table, so as to make the deeper parts of mineral veins available for exploitation.
Access rights in Scotland and geological fieldwork
Authors: Mackay John W.
Published: April 2007

Perhaps you may have always assumed that there was no law of trespass in Scotland, as is sometimes said. The legal profession assert that this is not the case, but there remains a strong popular belief in the existence of some kind of common law right of access to land in Scotland, especially in exercising traditional freedoms of access to the hills. This article sets out the position in Scotland since the enactment of new legislation in 2005 for access to land, relevant to geological fieldwork.
In Search of Optimised Regional Trade Agreements and Applications to East Asia
Authors: Lee Hongshik , Park Innwon
Published: April 2007

We quantitatively analyse the trade effects of enhanced trade facilitation with extended gravity equations. Our findings confirm that RTAs comprised of countries equipped with better trade facilitation are more likely to be trade‐creating, less likely to be trade‐diverting, and are thus more likely to lead the world economy toward global free trade. We also find that (i) the traditional gains from shallow integration through eliminating tariff barriers will be greater for South‐South RTAs in East Asia such as an ASEAN‐China RTA, provided that the tariff‐reducing schedule is strictly fulfilled, (ii) the gains from deeper integration through enhancing trade facilitation will be greater for North‐North RTAs in East Asia such as a Japan‐Korea RTA, and (iii) the gains from a combined trade liberalisation strategy through tariff reductions and enhanced trade facilitation will be greater for North‐South RTAs in East Asia such as a China‐Korea and an ASEAN+3 RTA.
Partnership with and without trade unions in the UK financial services: filling or fuelling the representation gap?
Authors: Tailby Stephanie , Richardson Mike , Upchurch Martin , Danford Andy , Stewart Paul
Published: April 2007

Partnership theory proposes that an appropriate integration of direct and indirect employee participation mutually benefits the workers and the company. This study explores the putative employee voice gains and the risks for union effectiveness by comparing employees' evaluation of partnership practices at two financial service companies with non‐union and union employee representation, respectively.
Proposal of an Algorithm for Diagnosis and Treatment of Neonatal Seizures in Developing Countries
Authors: Co John Patrick T. , Elia Maurizio , Engel Jerome , Guerrini Renzo , Mizrahi Eli M. , Moshé Solomon L. , Plouin Perrine
Published: April 2007

Summary:  Seizures in the neonatal period are common. They can be caused by a variety of conditions, ranging from benign, self‐limited illnesses to severe, life‐threatening disorders. They are often the first sign of neurologic dysfunction in neonates, and may be used as one factor in considering long‐term prognosis. An important mission of the International League Against Epilepsy (ILAE) is to improve the care of patients with epilepsy. Most recently, as part of the Global Campaign against Epilepsy, ILAE, in conjunction with the World Health Organization (WHO), established a new initiative to create clinical guidelines and diagnostic and management algorithms for the care of patients with seizures that can be applied worldwide, including in developing countries with limited or varied medical resources. Created by an international panel of experts in seizure management and guideline development, this document proposes guidelines for the diagnosis and management of the most common and important conditions that cause seizures in the neonatal period. The publication of these clinical pathways for neonatal seizures will be followed by a period of field testing and comment by WHO clinicians and officials before finalization.
Impact of Mandatory Physician Reporting on Accident Risk in Epilepsy
Authors: McLachlan Richard S , Starreveld Elout , Lee Mary Ann
Published: April 2007

Summary:  Background: In some jurisdictions, physicians are required by law to report patients with seizures to the department of motor vehicles. We assessed the hypothesis that mandatory reporting reduces the risk of automobile accidents in people with epilepsy.

Methods: A retrospective survey of driving and accident rates was done by mailed questionnaire to two groups of subjects with epilepsy in Canada, one living in Ontario where reporting is mandatory and the other in Alberta where it is not. Responses were obtained from a control group without epilepsy for comparison.

Results: The epilepsy (n = 425) and control (n = 375) groups were comparable in age and sex. Seventy‐three percent of the epilepsy group were or had been licensed drivers compared to 94% of the controls (rr 0.77, 95% CI 0.73–0.83, p < 0.001). Lifetime accident rate of licensed drivers was 58% in epilepsy and 60% in controls (rr 0.99, 95%CI 0.82–1.19, ns) while 9% of the epilepsy group and 9% of the controls had an accident in the previous year (rr 1.00, 95%CI 0.95–1.06, ns). All those with epilepsy in Ontario (n = 202) and Alberta (n = 223), also comparable in age and sex, had equal lifetime accident rates of 45 and 46% (rr 0.99, 95%CI 0.67–1.47, ns) and 1‐year rates of 11 and 8% (rr 1.38, 95%CI 0.59–3.27, ns). In Ontario, 20% of drivers were unlicensed compared to 9% in Alberta (rr 2.39, 95%CI 1.17–4.89, p = 0.01)

Conclusion: Although it is clearly dangerous for many people with ongoing seizures to drive, the findings provide no support for the hypothesis that mandatory reporting of patients by physicians reduces accident risk and suggest that concerns about the impact of epilepsy on driving compared to other medical and nonmedical risk factors may be excessive.
Decreased Efficacy of GABAA‐receptor Modulation by Midazolam in the Kainate Model of Temporal Lobe Epilepsy
Authors: Liefaard Lia C. , Gunput Rou‐Afza F. , Danhof Meindert , Voskuyl Rob A.
Published: April 2007

Summary:  Purpose: The objective of this investigation was to characterize quantitatively the time‐dependent changes in midazolam (MDL) efficacy in the silent period after induction of status epilepticus (SE) in rats. The changes in MDL efficacy were correlated to changes in ex vivo GABAA‐receptor expression.

Methods: MDL efficacy was quantified by pharmacokinetic–pharmacodynamic (PK‐PD) modeling by using the β‐frequency of the EEG as PD end point. Two PK‐PD experiments were performed in each animal: the first experiment before and the second experiment at either day 4 or day 14 after SE. SE was induced by repetitive intraperitoneal injections with kainate. GABAA‐receptor expression was determined by ex vivo autoradiography with [3H]flumazenil.

Results: The concentration versus EEG effect relation of midazolam was successfully described by the sigmoidal Emax model. The maximal effect on the β‐frequency of the EEG (Emax) was reduced to 51.6 ± 35.6% and 25.8 ± 33.7% of the original value at 4 and 14 days after induction of SE. The ex vivo study with [3H]flumazenil showed that the observed reductions in Emax were paralleled by a reduction in GABAA‐receptor density.

Conclusions: The efficacy of MDL is decreased in the silent period after SE, which can be partly accounted for by a reduction in GABAA‐receptor density.
Reduced Hippocampal 5HT1A PET Receptor Binding and Depression in Temporal Lobe Epilepsy
Authors: Theodore William H. , Hasler Gregor , Giovacchini Giampiero , Kelley Kathleen , Reeves‐Tyer Pat , Herscovitch Peter , Drevets Wayne
Published: April 2007

Summary:  Purpose: To study the relation of hippocampal 5HT1A receptor binding to symptoms of depression in patients with temporal lobe epilepsy. Depression is common in people with epilepsy, and reduced 5HT1A binding has been reported in patients with primary depressive disorders.

Methods: We studied 45 patients with temporal lobe epilepsy confirmed by ictal video‐EEG recording. Mood was assessed with the Beck Depression Inventory (BDI). Positron emission tomographic measurement of 5HT1A receptors was performed with 18F‐FCWAY, a highly specific silent antagonist. 3D‐T1‐weighted MRI was used to correct for structural atrophy. Receptor distribution volume (V) was corrected for plasma tracer free fraction (f1).

Results: There was a significant inverse relation between ipsilateral hippocampal v/f1 and the BDI. For contralateral hippocampus, there was a nonsignificant trend. Patients with BDI > 20 had significantly lower ipsilateral hippocampal V/f1 than patients in the low and medium groups. There was no significant effect of the presence of mesial temporal sclerosis, focus laterality, or gender on the BDI.

Conclusions: Our study shows a relationship between hippocampal 5HT1A binding and depressive symptoms measured by the BDI in patients with epilepsy. The findings parallel results in patients with MDD.