bluuebunny/crossref_metadata_2025 huggingface dataset:
Postoperative Analgesia after Radical Retropubic Prostatectomy
Authors: Gupta Anil , Fant Federica , Axelsson Kjell , Sandblom Dag , Rykowski Jan , Johansson Jan-Erik , Andersson Swen-Olof
Published: September 2006

Background

Postoperative pain after radical retropubic prostatectomy can be severe unless adequately treated. Low thoracic epidural analgesia and patient-controlled intravenous analgesia were compared in this double-blind, randomized study.

Methods

Sixty patients were randomly assigned to receive either low thoracic epidural analgesia (group E) or patient-controlled intravenous analgesia (group P) for postoperative pain relief. All patients had general anesthesia combined with thoracic epidural analgesia during the operation. Postoperatively, patients in group E received an infusion of 1 mg/ml ropivacaine, 2 microg/ml fentanyl, and 2 microg/ml adrenaline, 10 ml/h during 48 h epidurally, and a placebo patient-controlled intravenous analgesia pump intravenously. Patients in group P received a patient-controlled intravenous analgesia pump with morphine intravenously and 10 ml/h placebo epidurally. Pain, the primary outcome variable, was measured using the numeric rating scale at rest (incision pain and "deep" visceral pain) and on coughing. Secondary outcome variables included gastrointestinal function, respiratory function, mobilization, and full recovery. Health-related quality of life was measured using the Short Form-36 questionnaire, and plasma concentration of fentanyl was measured in five patients to exclude a systemic effect of fentanyl.

Results

Incisional pain and pain on coughing were lower in group E compared with group P at 2-24 h, as was deep pain between 3 and 24 h postoperatively (P < 0.05). Maximum expiratory pressure was greater in group E at 4 and 24 h (P < 0.05) compared with group P. No difference in time to home discharge was found between the groups. The mean plasma fentanyl concentration varied from 0.2 to 0.3 ng/ml during 0-48 h postoperatively. At 1 month, the scores on emotional role, physical functioning, and general health of the Short Form-36 were higher in group E compared with group P. However, no group x time interaction was found in the Short Form-36.

Conclusions

The authors found evidence for better pain relief and improved expiratory muscle function in patients receiving low thoracic epidural analgesia compared with patient-controlled analgesia for radical retropubic prostatectomy. Low thoracic epidural analgesia can be recommended as a good method for postoperative analgesia after abdominal surgery.
Clinical Implications of Mitochondrial Dysfunction
Authors: Muravchick Stanley , Levy Richard J. , Warltier David C.
Published: September 2006

Mitochondria produce metabolic energy, serve as biosensors for oxidative stress, and eventually become effector organelles for cell death through apoptosis. The extent to which these manifold mitochondrial functions are altered by previously unrecognized actions of anesthetic agents seems to explain and link a wide variety of perioperative phenomena that are currently of interest to anesthesiologists from both a clinical and a scientific perspective. In addition, many surgical patients may be at increased perioperative risk because of inherited or acquired mitochondrial dysfunction leading to increased oxidative stress. This review summarizes the essential aspects of the bioenergetic process, presents current knowledge regarding the effects of anesthetics on mitochondrial function and the extent to which mitochondrial state determines anesthetic requirement and potential anesthetic toxicity, and considers some of the many implications that our knowledge of mitochondrial dysfunction poses for anesthetic management and perioperative medicine.
Niche breadth and geographical range: ecological compensation for geographical rarity in rainforest frogs
Authors: Williams Yvette M , Williams Stephen E , Alford Ross A , Waycott Michelle , Johnson Christopher N
Published: September 2006

We investigated the relationship between diet specialization and geographical range inCophixalus, a genus of microhylid frogs from the Wet Tropics of northern Queensland, Australia. The geographical ranges of these species vary from a few square kilometres in species restricted to a single mountain top to the entire region for the widespread species. Although macroecological theory predicts that species with broad niches should have the largest geographical ranges, we found the opposite: geographically rare species were diet generalists and widespread species were diet specialists. We argue that this pattern is a product of extinction filtering, whereby geographically rare and therefore extinction-prone species are more likely to persist if they are diet generalists.
Anatomical basis for camouflaged polarized light communication in squid
Authors: Mäthger Lydia M , Hanlon Roger T
Published: September 2006

Camouflage is a means to defeat visual detection by predators, whereas visual communication involves a signal that is conspicuous to a receiver (usually a conspecific). However, most intraspecific visual signals are also conspicuous to predators, so that signalling can lead to the serious consequence of predation. Could an animal achieve visual camouflage and simultaneously send a hidden visual message to a conspecific? Here, we present evidence that the polarized aspect of iridescent colour in squid skin is maintained after it passes through the overlying pigmented chromatophores, which produce the highly evolved—and dynamically changeable—camouflaged patterns in cephalopods. Since cephalopods are polarization sensitive, and can regulate polarization via skin iridescence, it is conceivable that they could send polarized signals to conspecifics while staying camouflaged to fish or mammalian predators, most of which are not polarization sensitive.
Low intensity, mixed livestock grazing improves the breeding abundance of a common insectivorous passerine
Authors: Evans Darren M , Redpath Stephen M , Evans Sharon A , Elston David A , Gardner Charles J , Dennis Peter , Pakeman Robin J
Published: September 2006

Livestock grazing is a major driver of ecosystem change and has been associated with significant declines in various bird species in Britain and worldwide. However, there is little experimental evidence to show how grazing affects bird populations. We manipulated livestock densities in a replicated field experiment and found that mixed sheep and cattle grazing, at low intensity, improved the breeding abundance of a common upland passerine, the meadow pipit
Anthus pratensis
, after two years. Plots stocked with sheep alone (at high or low density) or not stocked at all held fewer pipit territories. Despite a year-on-year decline in pairs of meadow pipits in intensively grazed plots, we found no effect of sheep number on breeding abundance. Our results support the hypothesis that mixed species of herbivores generate greater heterogeneity in vegetation structure, which modifies prey availability, resulting in a greater abundance of birds. The results of our study should inform the management of grassland areas and enhance the abundance of some bird species, particularly in areas that have seen significant shifts from mixed livestock grazing to grazing dominated by single species of animals.
Embryonic nodal flow and the dynamics of nodal vesicular parcels
Authors: Cartwright Julyan H.E , Piro Nicolas , Piro Oreste , Tuval Idan
Published: September 2006

We address with fluid-dynamical simulations using direct numerical techniques three important and fundamental questions with respect to fluid flow within the mouse node and left–right development. First, we consider the differences between what is experimentally observed when assessing cilium-induced fluid flow in the mouse node
in vitro
and what is to be expected
in vivo
. The distinction is that
in vivo
, the leftward fluid flow across the mouse node takes place within a closed system and is consequently confined, while this is no longer the case on removing the covering membrane and immersing the embryo in a fluid-filled volume to perform
in vitro
experiments. Although there is a central leftward flow in both instances, we elucidate some important distinctions about the closed
in vivo
situation. Second, we model the movement of the newly discovered nodal vesicular parcels (NVPs) across the node and demonstrate that the flow should indeed cause them to accumulate on the left side of the node, as required for symmetry breaking. Third, we discuss the rupture of NVPs. Based on the biophysical properties of these vesicles, we argue that the morphogens they contain are likely not delivered to the surrounding cells by their mechanical rupture either by the cilia or the flow, and rupture must instead be induced by an as yet undiscovered biochemical mechanism.
The interplay between a self-organized process and an environmental template: corpse clustering under the influence of air currents in ants
Authors: Jost Christian , Verret Julie , Casellas Eric , Gautrais Jacques , Challet Mélanie , Lluc Jacques , Blanco Stéphane , Clifton Michael J , Theraulaz Guy
Published: September 2006

Many spatial patterns observed in nature emerge from local processes and their interactions with the local environment. The clustering of objects by social insects represents such a pattern formation process that can be observed at both the individual and the collective level. In this paper, we study the interaction between air currents and clustering behaviour in order to address the coordinating mechanisms at the individual level that underlie the spatial pattern formation process in a heterogeneous environment. We choose the corpse clustering behaviour of the antMessor sanctusas an experimental paradigm. In a specifically designed experimental set-up with a well-controlled laminar air flow (approx. 1 cm s−1), we first quantify the modulation of the individual corpse aggregation behaviour as a function of corpse density, air flow intensity and the ant's position with respect to corpse piles and air flow direction. We then explore by numerical simulation how the forming corpse piles modify the laminar air flow around them and link this result with the individual behaviour modulation. Finally, we demonstrate on the collective level that this laminar air flow leads to an elongation and a slow displacement of the formed corpse piles in the direction of the air current. Both the individual behaviour modulated by air flow and the air flow modulated by the forming corpse piles can explain the pile patterns observed on the collective level as a stigmergic process. We discuss the generality of this coordinating mechanism to explain the clustering phenomena in heterogeneous environments reported in the literature.
Rotation–vibrational states of and the adiabatic approximation
Authors: Alijah Alexander , Hinze Juergen
Published: September 2006

We discuss recent progress in the calculation and identification of rotation–vibrational states of

at intermediate energies up to 13 000 cm
−1
. Our calculations are based on the potential energy surface of Cencek
et al
. which is of sub-microhartree accuracy. As this surface includes diagonal adiabatic and relativistic corrections to the fixed nuclei electronic energies, the remaining discrepancies between our calculated and experimental data should be due to the neglect of non-adiabatic coupling to excited electronic states in the calculations. To account for this, our calculated energy values were adjusted empirically by a simple correction formula. Based on our understanding of the adiabatic approximation, we suggest two new approaches to account for the off-diagonal adiabatic correction, which should work; however, they have not been tested yet for

. Theoretical predictions made for the above-barrier energy region of recent experimental interest are accurate to 0.35 cm
−1
or better.
Electron-impact rotational excitation of : relevance for thermalization and dissociation dynamics
Authors: Faure Alexandre , Wiesenfeld Laurent , Valiron Pierre , Tennyson Jonathan
Published: September 2006

Electrons are known to be efficient in rotationally exciting molecular ions in low-density astrophysical plasmas. Rotational excitation of molecular ions has also been shown to affect the measured values of dissociative recombination (DR) rate coefficients. Thus, electron collisions with

are expected to play a significant role in thermalization and dissociation dynamics of this ion, both in the laboratory and in space. Using the molecular

R

-matrix method combined with the adiabatic-nuclei-rotation approximation, we have computed new rate coefficients for the rotational excitation of

by electrons at temperatures from 10 to 10 000 K. De-excitation rates are found to amount to a few 10
−7
 cm
3
 s
−1
below 1000 K, i.e. comparable in magnitude to that of DR. In astrophysical environments where the electron fraction exceeds 10
−4
, electron collisions are thus expected to contribute to the non-thermal rotational distribution of

. The competition between electron and neutral collisions is discussed in the context of recent observations of

towards Galactic centre sources.
towards and within the Galactic centre
Authors: Geballe T.R
Published: September 2006

High-resolution spectroscopy of bright infrared sources in the centre of the Galaxy has resulted in the detection of

in a remarkable array of dense and diffuse clouds along the 8000 parsec long line of sight, at a wide range of distances from the centre. Most prominent among these is a previously undetected, but very large amount of warm (
T
∼250 K) and diffuse (
n
∼100 cm
2
) gas within a few hundred parsecs of the centre. The key to understanding the environment of the

in this region is an

absorption line at 3.53 μm from the metastable (3,3) rotational level, which has not been detected in dense or diffuse clouds outside of the Galactic centre (GC). We have used spectroscopy of this line along with other lines of

and CO to characterize all of the clouds along the line of sight to the GC. The high abundance of

in the central few hundred parsecs implies an ionization rate there that is several times larger than estimated for diffuse clouds outside the GC, and nearly two orders of magnitude greater than originally predicted for diffuse clouds.
cooling in primordial gas
Authors: Glover Simon , Savin Daniel Wolf
Published: September 2006

Simulations of the thermal and dynamical evolution of primordial gas typically focus on the role played by H
2
cooling. H
2
is the dominant coolant in low-density primordial gas and it is usually assumed that it remains dominant at high densities. However, H
2
is not an effective coolant at high densities, owing to the low critical density at which it reaches local thermodynamic equilibrium and to the large opacities that develop in its emission lines. It is therefore important to quantify the contribution made to the cooling rate by emission from the other molecules and ions present in the gas. A particularly interesting candidate is the

ion, which is known to be an effective coolant at high densities in planetary atmospheres. In this paper, we present results from simulations of the thermal and chemical evolution of gravitationally collapsing primordial gas, which include a detailed treatment of

chemistry and an approximate treatment of

cooling. We show that in most cases, the contribution from

is too small to be important, but if a sufficiently strong ionizing background is present, then

cooling may become significant.
Near-infrared spectroscopy of above the barrier to linearity
Authors: Gottfried Jennifer L
Published: September 2006

Since the Royal Society Discussion Meeting on

in 2000, the laboratory spectroscopy of

has entered a new regime. For the first time, transitions of

above the barrier to linearity have been observed. A highly sensitive near-infrared spectrometer based on a titanium:sapphire laser and incorporating a dual-beam, double-modulation technique with bidirectional optical multi-passing has been developed in order to detect these transitions, which are more than 4600 times weaker than the fundamental band. We discuss our recent work on the

,

,

,

and

combination bands and the

,

,

and

overtone bands. Experimentally determined energy levels provide a critical test of
ab initio
calculations in this challenging energy regime (greater than 10 000 cm
−1
). By comparing the experimental energy levels and theoretical energy levels from
ab initio
calculations in which the adiabatic and relativistic corrections are incorporated, the extent of higher-order effects such as non-adiabatic and radiative corrections is revealed.
Theoretical progress and challenges in dissociative recombination
Authors: Greene Chris H , Kokoouline V
Published: September 2006

We discuss the Jahn–Teller mechanism for dissociative recombination in low energy collisions between electrons and

ions, in energy ranges relevant to the processes underway in interstellar clouds. While theory has become capable of predicting recombination rates in reasonable agreement with storage ring experiments, some discrepancies remain with them, and a long-standing discrepancy with stationary afterglow measurements remains troubling. Speculations about the desirable improvements in both theory and experiment are presented.
Introductory remarks
Authors: Oka Takeshi
Published: September 2006

The inspiring developments in astronomy, physics and chemistry of

since 2000, which led to this Royal Society Discussion Meeting, are reviewed.
Spectro-imaging observations of on Jupiter
Authors: Lellouch Emmanuel
Published: September 2006

Narrow-band filter, high-spectral-resolution (0.2 cm
−1
) spectro-imaging infrared observations of Jupiter's auroral zones, acquired in October 1999 and October 2000 with the FTS/BEAR instrument at the Canada–France–Hawaii Telescope, have provided maps of the emission from the H
2
S
1
(1) quadrupole line and several

lines. H
2
and

emissions appear to be morphologically different, especially in the north, where the latter notably exhibits a ‘hot spot’ near
λ
III
=150–170° System III longitude. The spectra include a total of 14

lines, including two hot lines from the 3
ν
2
–
ν
2
band, detected on Jupiter for the first time. They can be used to determine

column densities, rotational (
T
rot
) and vibrational (
T
vib
) temperatures. We find the mean
T
vib
of the
ν
2
=3 state to be lower (960±50 K) than the mean
T
rot
in
v
2
=2 (1170±75 K), indicating an underpopulation of the
v
2
=3 level with respect to local thermodynamical equilibrium. Rotational temperatures and associated column densities are generally higher and lower, respectively, than inferred previously from
ν
2
observations. These features can be explained by the combination of both a large positive temperature gradient in the sub-microbar auroral atmosphere and non-local thermal equilibrium effects affecting preferentially hot and combination bands. Spatial variations in line intensities are mostly owing to correlated variations in the

column densities. The thermostatic role played by

at ionospheric levels may provide an explanation. The exception is the northern ‘hot spot’, which exhibits a
T
vib
about 250 K higher than other regions.
in the diffuse interstellar medium
Authors: Liszt Harvey S
Published: September 2006

Three forms of solely hydrogen-bearing molecules—H
2
, HD and

—are observed in diffuse or optically transparent interstellar clouds. Although no comprehensive theory exists for the diffuse interstellar medium or its chemistry, the abundances of these species can generally be accommodated locally within the existing static equilibrium frameworks for heating/cooling, H
2
-formation on large grains, etc. with one modification demanded equally by observations of HD and

, i.e. a pervasive low-level source of H and H
2
ionization
ca
10 times faster than the usual cosmic ray ionization rate
ζ
H
≈10
−17
 s
−1
per free H-atom.

We discuss this situation with reference to observation and time-dependent modelling of H
2
and

formation. While not wishing to appear ungrateful for the success of what are very simplistic notions of the interstellar medium, we point out several reasons not to feel smug. The equilibrium conditions which foster high H
2
and

abundances are very slow to appear and these same simple ideas of static equilibrium cannot explain any, but a few, of the simplest of the trace species, which are ubiquitously embedded in H
2
-bearing diffuse gases.
Using H
3
+
and H
2
D
+
as probes of star-forming regions
Authors: van der Tak Floris F.S
Published: September 2006

The

and H
2
D
+
ions are important probes of the physical and chemical conditions in regions of the interstellar medium where new stars are forming. This paper reviews how observations of these species and of heavier ions such as HCO
+
and H
3
O
+
can be used to derive chemical and kinematic properties of nearby pre-stellar cores and the cosmic ray ionization rate towards more distant regions of high-mass star formation. Future prospects in the field are outlined at the end.
Correction and addendum to Oka 2000: introductory remarks
Authors: Oka Takeshi
Published: September 2006

My earlier assignment of the

signal in J. J. Thomson's plate is corrected. The double nature of the
m
/
e
=3 signal, one due to

and the other to HD
+
, which puzzled Thomson for over 20 years, is discussed.
A family with hereditary thrombocythaemia and normal genes for thrombopoietin and c‐Mpl
Authors: Tecuceanu N. , Dardik R. , Rabizadeh E. , Raanani P. , Inbal A.
Published: September 2006

Hereditary thrombocythaemia (HT) is an inherited autosomal dominant disorder. Recent studies reported six different mutations, four within the thrombopoietin (TPO) gene and two within c‐Mpl (TPO receptor) gene in six unrelated families with HT. This study investigated the molecular basis of hereditary thrombocythaemia in an Israeli‐Jewish family. We screened the genes for TPO and c‐Mpl by amplification and sequencing of all the corresponding exons including exon/intron boundaries and promoters. In addition, plasma levels of TPO and erythropoietin (EPO) were measured. No abnormality in the TPO/c‐Mpl genes has been identified in affected HT family members. Plasma TPO and EPO levels were found to be normal/low or normal respectively in the individuals affected. In conclusion, lack of a molecular lesion within either TPO or cMpl genes indicate that HT may be caused by factors other than TPO‐cMpl axis in this family.
Severe mucositis is associated with reduced survival after autologous stem cell transplantation for lymphoid malignancies
Authors: Fanning S. R. , Rybicki L. , Kalaycio M. , Andresen S. , Kuczkowski E. , Pohlman B. , Sobecks R. , Sweetenham J. , Bolwell B.
Published: September 2006

Mucositis is a known complication of autologous stem cell transplantation (ASCT). This study retrospectively reviewed 191 patients with lymphoid malignancies undergoing ASCT following a uniform mobilising regimen of etoposide (VP‐16)/granulocyte colony‐stimulating factor and a uniform high‐dose preparative regimen of busulfan/cyclophosphamide/VP‐16. Eighty‐seven patients experienced severe mucositis (modified Oral Mucositis Assessment Scale ≥1). Patient characteristics compared between mucositis groups were balanced according to disease status, prior exposure to radiation therapy, time from radiation therapy and actual body weight. Log‐rank analysis revealed that severe mucositis was associated with inferior overall survival (P = 0·002). A 12‐month landmark analysis showed this difference in survival occurred within 1 year post‐transplant. Multivariate analysis of all‐cause mortality showed lower pretransplant albumin and severe mucositis to be significant risk factors. Multivariate analysis for relapse mortality revealed severe mucositis to be a risk factor (P = 0·047), while lower pretransplant albumin was significant for non‐relapse mortality (NRM; P = 0·009). Kaplan–Meier estimates of survival based on relapse and NRM were significantly worse for patients with severe mucositis. Reduced pretransplant forced expiratory volume in 1 s (FEV1) and carbon monoxide (CO) diffusing capacity (DLCO) were also associated with severe mucositis. Our data suggest that studies of new treatment strategies for mucositis should include relapse and survival endpoints and that pretransplant factors, such as FEV1 and DLCO may be useful to risk‐stratify patients entered onto such trials.
Reconstitution of the T‐cell repertoire following treatment with alemtuzumab (anti‐CD52 monoclonal antibody) in patients with B‐cell chronic lymphocytic leukaemia
Authors: Rezvany Mohammad Reza , Tehrani Mahmood Jeddi , Karlsson Claes , Lundin Jeanette , Rabbani Hodjattallah , Österborg Anders , Mellstedt Håkan
Published: September 2006

In this pilot study, T‐cell receptor B‐variable (TCR‐BV) gene usage in CD4 and CD8 T cells was assessed, by real‐time polymerase chain reaction, as well as complementarity‐determining region 3 (CDR3)‐length polymorphism, before and after therapy in five patients with B‐cell chronic lymphocytic leukaemia who received alemtuzumab (anti‐CD52 monoclonal antibody) as first‐line therapy. A decline in expression of most BV family genes in both CD4 and CD8 T cells was observed after alemtuzumab treatment, which was followed by a gradual increase in most BV families during long‐term follow‐up. After treatment, CDR3‐length polymorphism showed an even more restricted pattern in CD4 T cells compared with pretreatment, with a shift towards a monoclonal/oligoclonal pattern. The clonally restricted pattern was significantly reduced in CD4 (P < 0·01) but not in CD8 T cells. This was followed by a gradual increase in the number of peaks within the CDR3 region of the different TCR‐BV families, i.e. a polyclonal repertoire, during long‐term follow‐up. A restricted CDR3 pattern became even more restricted after treatment, but normalised during unmaintained follow‐up. These results indicate that perturbations in the T‐cell alterations following alemtuzumab are complex and include not only changes in CD4/CD8 T‐cell numbers but also a highly restricted T‐cell repertoire especially in CD4 T cells.
Multiple myeloma patients with CKS1B gene amplification have a shorter progression‐free survival post‐autologous stem cell transplantation
Authors: Chang Hong , Qi Xiaoying , Trieu Young , Xu Wei , Reader Jocelyn C. , Ning Yi , Reece Donna
Published: September 2006

The prevalence and prognostic relevance of recurrent gains of CKS1B (cyclin kinase subunit 1B) gene at chromosome 1q21 region was investigated by interphase fluorescence in situ hybridisation in a cohort of 99 multiple myeloma (MM) patients treated with intensive chemotherapy followed by autologous stem cell transplantation. CKS1B amplification (3–8 CKS1B signals) was detected in 31of 99 (31%) patients and was associated with deletions of p53 (P = 0·003) and 13q (P = 0·039) but not with translocation t(11;14) or t(4;14). CKS1B amplification was associated with bone marrow plasmacytosis (P = 0·02), but there was no correlation with patient age, gender, disease stage, lytic bone lesions, albumin, creatinine, C‐reactive protein or beta‐2 microglobulin levels. Patients with CKS1B amplification had a significantly shorter progression‐free survival than those without such amplification (18·5 vs. 25·7 months, P = 0·035). Likewise, a shorter overall survival (44·8 months vs. not reached) was observed; however, the difference did not reach statistical significance (P = 0·20). Seven patients had paired bone marrows obtained at diagnosis and at relapse, the percentage of cells with CKS1B amplification and the level of amplification were significantly increased in the relapse marrows. In this cohort of patients, CKS1B was frequently amplified in MM and may represent genetic instability associated with disease progression.
The role of nitrogen in promoting the toxic cyanophyte Cylindrospermopsis raciborskii in a subtropical water reservoir
Authors: BURFORD MICHELE A. , MCNEALE KAREN L. , MCKENZIE‐SMITH FIONA J.
Published: September 2006

1. The relative contribution of dissolved and atmospheric nitrogen to promoting dominance of the toxic nitrogen‐fixing cyanobacterium, Cylindrospermopsis raciborskii was examined in a subtropical water reservoir, North Pine Reservoir.

2. A combination of process studies in situ and analysis of historical water quality data suggests that nitrogen fixation was not the principal mechanism for acquiring nitrogen and unlikely to be the mechanism whereby C. raciborskii gains a competitive advantage. Ammonium was the preferred nitrogen source, followed by nitrate then nitrogen fixation.

3. Ammonium uptake rates in the euphotic zone were higher in the summer and autumn months compared with winter and spring coinciding with lower ammonium concentrations. Nitrate uptake rates did not appear to vary seasonally and were lower than those for ammonium in the summer, but similar in winter. Nitrate concentrations were higher in winter than summer and generally higher than ammonium concentrations.

4. Ammonium and nitrate uptake rates were similar at light intensities between 10% and 100% of surface light, contrasting with primary productivity which peaked between about 10 to 20% of surface light. Thus the phytoplankton population was adapted to low light conditions but remained able to utilise dissolved inorganic nitrogen over a wide range of light conditions.

5. The ammonium pool in the surface waters was relatively small compared with the phytoplankton uptake rates, and ammonium must therefore be rapidly recycled through the food web over periods of less than 1 h. Short‐term depletion may result, during which time the higher concentrations of nitrate are likely to provide a supplementary supply of nitrogen.

6. The dominance of C. raciborskii in this reservoir is more likely to be due to a superior ability to scavenge and store the low concentrations of phosphate, and a superior adaptation to the low light conditions exacerbated by artificial mixing.
The debate about drag and reconfiguration of freshwater macrophytes: comparing results obtained by three recently discussed approaches
Authors: STATZNER BERNHARD , LAMOUROUX NICOLAS , NIKORA VLADIMIR , SAGNES PIERRE
Published: September 2006

1. The paper by Sand‐Jensen (2003, Freshwater Biology, 48, 271–283) on drag and reconfiguration of freshwater macrophytes stimulated comments and a reply about the use of variables in assessments of the drag coefficient (Cd) or the Reynolds number (Re) of such plants. Although the physical argument in this debate starts from the same equations, it diverges into approaches that address differently the dynamic behaviour of flexible plants in the boundary layer flow (the typical condition experienced by lotic macrophytes).

2. We compared three (potentially among many more) such different approaches using some preliminary experiments with Egeria densa by measuring drag (and other physical variables of interest) on (1) a single shoot exposed to varying flume flows; (2) a single shoot exposed to a constant flume flow, from which we subsequently pruned off pieces from the distal end; and (3) multiple shoots exposed to a constant flume flow after they had experienced replicated flow disturbances (causing shoot reconfiguration).

3. These experiments illustrated that the three approaches can produce opposite trends in the relationship between Cd and Re and that, for a given plant and flow, the Cd values obtained by these approaches can differ by about two orders of magnitude. Thus, conventions about the use of variables are required for experiments on drag and reconfiguration of freshwater macrophytes, otherwise the field will be plagued by a multitude of incomparable results.
Predation by the tropical plant Utricularia foliosa
Authors: SANABRIA‐ARANDA LIZANDRO , GONZÁLEZ‐BERMÚDEZ ADRIANA , TORRES NÉSTOR NED , GUISANDE CÁSTOR , MANJARRÉS‐HERNÁNDEZ ANA , VALOYES‐VALOIS VANESSA , DÍAZ‐OLARTE JHON , ANDRADE‐SOSSA CAMILO , DUQUE SANTIAGO R.
Published: September 2006

1. We examined the prey captured by individual plants of the tropical carnivorous plant Utricularia foliosa, located in different areas along a creek in the Colombian Amazon and the zooplankton and macroinvertebrate communities associated with the plants. The aims were: (i) to determine whether bladders of different sizes within each plant catch different numbers of prey or exploit different size ranges and types of prey, (ii) if the quantity and composition of prey captured varies temporally and/or spatially and (iii) if the plant has evolved effective mechanisms of attracting prey.

2. Utricularia foliosa captured the most abundant species of macroinvertebrates associated with the plant. Larger bladders captured more, larger and more diverse prey. However, benefits of the extra prey caught by large bladders were not offset by the greater cost of producing bladders larger than approximately 1650 μm.

3. The number of prey captured was higher in those plants with more carbohydrates per bladder and with a higher ratio of antenna size/bladder length. The antennae enhance capture success by offering the prey a favourable substratum that exploits their natural locomotor and feeding behaviour. However, although carbohydrates may lure prey, carbohydrate production was not a strategy of the plant to enhance the capture of prey, because the amount of carbohydrates in the bladder was related to the abundance of periphyton.
The various strategies within the TyrR regulon of Escherichia coli to modulate gene expression
Authors: Pittard James
Published: September 2006

The TyrR Regulon of Escherichia coli comprises eight transcription units whose expression is modulated by the TyrR protein. This protein, which is normally a homodimer in solution, can self‐associate to form a hexamer, bind with high affinity to specific DNA sequences (TyrR boxes) and interact with the α subunit of the RNA polymerase. These various reactions are influenced by the abundance of one or more of the aromatic amino acids, tyrosine, phenylalanine or tryptophan and by the specific location and sequence of the TyrR boxes associated with each transcription unit. This review describes how these activities can be combined in different ways to produce a variety of responses to varying levels of the three aromatic amino acids.
Runt domain partner proteins enhance DNA binding and transcriptional repression in cultured Drosophila cells
Authors: Fujioka Miki , Yusibova Galina L , Sackerson Charles M. , Tillib Sergei , Mazo Alexander , Satake Masanobu , Goto Tadaatsu , Suzuki Yoshiaki
Published: September 2006

Background: The Drosophila gene runt plays multiple roles during embryogenesis, including one as a pair‐rule class segmentation gene. The runt protein (Runt) contains an evolutionarily conserved domain (the Runt domain) that is found in several mammalian proteins including the human protein AML1, which is involved in many chromosome translocations associated with leukaemia. Specific DNA binding activity of a mammalian Runt domain is enhanced by a partner protein called PEBP2β/CBFβ. DNA binding activity of Drosophila Runt is also stimulated by this protein, suggesting the existence of a similar Runt partner protein in Drosophila.

Results: We report here the cloning of two closely linked Drosophila genes, runt domain partner (rp) β1 and β2, that encode homologues of mouse PEBP2β/CBFβ. They are highly homologous to each other and to the mammalian counterpart. Either of the rpb proteins is capable of forming a complex with Runt and stimulating its DNA binding activity, but their temporal and spatial distributions are quite dissimilar, suggesting that functional specificity of Runt may be conferred by the interacting partner. Runt represses transcription dominantly when coexpressed with either partner in cultured cells, a function consistent with a direct role for Runt in regulating expression of the even‐skipped gene in Drosophila embryos.

Conclusions: Drosophila Runt can interact with either of two Runt domain partners, and the resulting complex functions as an active repressor of transcription.
BMP‐4 mediates interacting signals between the neural tube and skin along the dorsal midline
Authors: Takahashi Yoshiko , Tonegawa Akane , Matsurnoto Kazuyuki , Ueno Naoto , Kuroiwa Atsushi , Noda Masaki , Nifuji Akira , Kondoh Hisato
Published: September 2006

Background: The neural tube and its overlying tissues (skin and mesenchyme) interact along the dorsal midline during early development. This has been previously demonstrated experimentally in chicken embryos by the fact that the dorsal neural tube transplanted ectopically induced expression of Msx 2 in the adjacent tissues. It is important to identify the molecules responsible for these interactions.

Results: We observed that BMP‐4, a member of the TGFβ‐family, is expressed in the dorsal neural tube in a pattern closely correlated with that of Msx 2. hi order to investigate whether BMP‐4 mediates the signal between the neural tube and the skin/ mesenchyme, BMP‐4 was ectopically administered in ovo either by implantation of the recombinant protein or transplantation of COS cells producing BMP‐4. Both manipulations resulted in ectopic induction of Msx 2 expression in the adjacent skin/mesenchyme. In addition, the activity of BMP‐4 in inducing Msx 2 was counteracted by the floor plate.

Conclusion: These data suggest that BMP‐4 positively mediates the signals from the neural tube to the adjacent tissues and that this signal may be an essential step for the establishment of the dorsal midline structures.
The innate host defence against nematode parasites
Authors: DE VEER M. J. , KEMP J. M. , MEEUSEN E. N. T.
Published: September 2006

Nematode parasites cause significant infections in both humans and animals. They are complex, multicellular organisms that present unique challenges for the host, in particular with respect to the recognition of their unusual surface structures by the innate defence system. The innate immune system is now recognized to be a critical component in the development of an adaptive effector response as well as a driver of vaccine‐induced immunity. This paper will give an overview of current research on the innate barriers and immune mechanisms, cells, and receptors involved in the innate host response to nematode parasites. It will also review the ‘nematode‐associated molecular patterns’ that may be specifically recognized by the host, in addition to other signals, such as nervous stimulation and tissue damage, that may alert the innate system to parasite invasion.
HIV and helminth co‐infection: is deworming necessary?
Authors: BORKOW G. , BENTWICH Z.
Published: September 2006

We have previously suggested that helminth infections play a major role in the pathogenesis of HIV‐1 infection in Africa and other developing areas, due to their profound effects on the host immune system, which make those infected more susceptible to HIV‐1 infection and less able to cope with it. Chronic immune activation with a dominant Th2 profile, and anergy, are the hallmarks of chronic helminth infection, and may therefore account for most of these effects. In the present review, we summarize the studies that have addressed these issues and argue that despite some conflicting results, the cumulative immunological and epidemiological evidence is in favour of deworming as a preventive and possible therapeutic measure vis‐à‐vis HIV‐1 infection. We suggest that it should be at least tested on a wider and larger scale than has been done until now, because of its immense potential impact on the still raging AIDS epidemic in developing countries.
Volatile metabolite profiling to detect and discriminate stem‐end rot and anthracnose diseases of mango fruits
Authors: Moalemiyan M. , Vikram A. , Kushalappa A. C. , Yaylayan V.
Published: September 2006

The volatile metabolites from the headspace gas of containerised mango (Mangifera indica) cv. Tommy Atkins fruits, surface wounded and inoculated with the two fungal anamorphic pathogens Colletotrichum gloeosporioides and Lasiodiplodia theobromae, or non‐inoculated (controls), were profiled using a portable gas chromatograph/mass spectrometer to discriminate diseases of mango. Thirty‐four compounds were detected relatively consistently among replicates. Several of these were disease/inoculation‐discriminatory and were classified into three groups: (i) compounds unique to only one treatment; (ii) compounds common to two or more treatments, but not to all; and (iii) compounds common to all treatments, but varying in their abundance. Two compounds, 1‐pentanol and ethyl boronate, were detected in L. theobromae‐inoculated mangoes alone, while thujol was observed only in C. gloeosporioides‐inoculated mangoes. Discriminant analysis models based on the abundance of significant mass ions and consistent compounds correctly classified diseases/inoculations in up to 100% of cases. The disease‐discriminatory compounds and discriminant analysis models developed here have the potential to be used in the early detection of postharvest diseases of mango fruits after validation under commercial conditions.
Environmental and host requirements for field infection of blueberry fruits by Colletotrichum acutatum in British Columbia
Authors: Verma N. , MacDonald L. , Punja Z. K.
Published: September 2006

Higher recovery of Colletotrichum acutatum, the causal agent of anthracnose (ripe‐rot), from blueberry tissues during the growing seasons of 2002 and 2003 was found at bloom and ripe berry than at other stages of plant development. The effects of leaf‐wetness duration and ambient temperature on fruit infection frequency were determined during the growing seasons of 2001–03. Potted 2‐year‐old blueberry plants were exposed for 1‐week periods to prevailing environmental conditions and natural inoculum in a commercial field, and grown to harvest, when fruit infection was assessed. Three peaks of infection were observed: early during bloom, mid‐season during the mature green berry stage, and later in the season when berries had ripened. Weather data collected simultaneously indicated that a minimum of 10 h of leaf wetness at 11°C was sufficient for fruit infection. These conditions preceded each peak of infection. To determine whether peaks of infection in the field were also caused by changes in host susceptibility or available inoculum, groups of potted blueberry plants were artificially inoculated at weekly intervals during the growing season of 2004, exposed to prevailing environmental conditions, and fruit infection assessed at harvest. Flowers and developing fruits were found to be susceptible throughout the season, indicating that specific peaks of infection were associated with environmental conditions and availability of inoculum.
Late‐blight epidemics on potato in Finland, 1933–2002; increased and earlier occurrence of epidemics associated with climate change and lack of rotation
Authors: Hannukkala A. O. , Kaukoranta T. , Lehtinen A. , Rahkonen A.
Published: September 2006

Changes in the incidence and onset of potato late‐blight epidemics in Finland were investigated and compared with possible changes in climate, presence of soil‐borne inoculum, and aggressiveness of Phytophthora infestans populations. Datasets were constructed from leaf blight assessments in cultivar trials or fungicide tests carried out at eight experimental sites during the periods 1933–1962 and 1983–2002. Additional data were obtained from late‐blight monitoring projects carried out from 1991 to 2002. From 1998 to 2002, the risk of blight outbreak was 17‐fold higher compared with the periods 1933–62 and 1983–1997. Simultaneously, the outbreaks of the epidemics began 2–4 weeks earlier. The changes observed were associated with a climate more conducive to blight in the late 1990s. Lack of rotation also advanced blight epidemics by an average of 9 days in 1998–2002, but it did not have this effect in 1992–1997, suggesting that soil borne inoculum may not have been a significant threat to potato until the late 1990s. The aggressiveness of the P. infestans isolates seemed to have only minor effect on the onset of the epidemics after 1991, as the apparent infection rate remained unchanged despite weather conditions more favourable to late blight in the late 1990s. As a consequence of the more frequent and earlier epidemics, the sales of fungicides used against late blight in Finland increased 4‐fold from the 1980s to 2002.
A lesion‐mimic mutant of wheat with enhanced resistance to leaf rust
Authors: Kamlofski C. A. , Antonelli E. , Bender C. , Jaskelioff M. , Danna C. H. , Ugalde R. , Acevedo A.
Published: September 2006

A lesion‐mimic mutant was obtained from a mutagenic treatment performed with ethyl methanesulfonate on the Argentine bread wheat (Triticum aestivum) cultivar Sinvalocho M.A. The HLP (hypersensitive‐like phenotype) mutant exhibited tiny, discrete, white lesions in the absence of any pathogen, resembling the typical hypersensitive response (HR). The lesions only became evident once the fifth or sixth leaf emerged, and spread at random along the leaf blades and leaf sheaths of the developing plant, including tissues of the spike. Because the lesion‐mimic mutant showed no lesions at the seedling stage, the phenotypes of both the mutant and its mother line were identical at this point. Histochemical studies showed that spontaneous hypersensitive‐like lesions in the HLP mutant corresponded to cell death. In leaf‐rust (Puccinia triticina) infection experiments performed at seedling and adult‐plant stages, adult HLP plants showed enhanced resistance to leaf‐rust attack compared with plants of Sinvalocho M.A. of comparable developmental stage, suggesting that the HLP mutation may confer increased resistance to the fungus. Because enhanced resistance coincided with the presence of spontaneous HR lesions, activation of HLP plant defence responses appeared to be tightly linked to this phenomenon. Final plant height and yield components in the lesion‐mimic mutant did not differ from those of the mother line, indicating that the HLP mutation caused no detrimental pleiotropic effects that significantly affected agronomic performance. These data support the direct use of mutations in disease‐resistance breeding.
Surface‐Bound Immunoglobulin on Lymphocytes from Normal and Immunodeficient Humans
Authors: FRØLAND S. S. , NATVIG J. B.
Published: September 2006

By means of immunofluorescence technique, lymphocytes with surface‐bound immunoglobulin were detected in the blood of normal humans F(ab')2, IgM, IgG, IgA, the four IgG subclasses, and the Gm markers Gm(f) and Gm(Z) were demonstrated on cells. IgM was the dominating class, and IgG2 the dominating IgG subclass. The data suggest that the Ig on any one cell belongs to a single class and IgG subclass. Very few lymphocytes stained for antigens on the C‐terminal half of ihe IgG molecule. Ig‐positive lymphocytes were also demonstrated in cord blood and in spleen cell suspensions. An almost total lack of Ig‐positive lymphocytes was demonstrated in the blood of 8 patients with severe hypogammaglobulinemia. The Ig‐positive lymphocytes are thought to be analogous to B‐lymphocytes in other species.