bluuebunny/crossref_metadata_2025 huggingface dataset:
Survival rates and causes of mortality of Amur tigers on and near the Sikhote‐Alin Biosphere Zapovednik
Authors: Goodrich J. M. , Kerley L. L. , Smirnov E. N. , Miquelle D. G. , McDonald L. , Quigley H. B. , Hornocker M. G. , McDonald T.
Published: May 2008

We examined causes of mortality and survival rates for Amur tigers on and near the Sikhote‐Alin Biosphere Zapovednik. Our objectives were to estimate and compare survival rates among sex and age classes, estimate cause‐specific mortality, identify conservation issues related to tiger mortality and provide recommendations for reducing human‐caused mortality. We used two separate datasets; one based on radio‐tracking tigers from 1992 to 2005 and one based on reports of dead tigers from 1976 to 2000. We examined causes of mortality for both datasets and used a Cox proportional hazards models to estimate survival rates using data from 42 radio‐collared tigers. Mortality was predominantly human‐caused for both datasets (83% for the telemetry dataset and 78% for the other, n=24 and 53 mortalities, respectively), and 75% of collared animals were poached. All collared subadult tigers that dispersed were poached (n=6). Annual survival of adult females (0.81±0.10) was greater than that of adult males (0.63±0.20) (z=1.52, P=0.13) and subadult males (0.41±0.46) (z=2.07, P=0.04). Survival rates were precariously low on our study area, which included the largest protected area within Amur tiger range. Efforts to reduce human‐caused mortality should focus on poaching and reducing deaths from tiger–human conflicts.
Heart rate variability response to alcohol, placebo, and emotional picture cue challenges: Effects of 0.1‐Hz stimulation
Authors: Vaschillo Evgeny G. , Bates Marsha E. , Vaschillo Bronya , Lehrer Paul , Udo Tomoko , Mun Eun Young , Ray Suchismita
Published: May 2008

Heart rate variability (HRV) supports emotion regulation and is reduced by alcohol. Based on the resonance properties of the cardiovascular system, a new 0.1‐Hz methodology was developed to present emotional stimuli and assess HRV reaction in participants (N=36) randomly assigned to an alcohol, placebo, or control condition. Blocked picture cues (negative, positive, neutral) were presented at a rate of 5 s on, 5 s off (i.e., 0.1‐Hz frequency). SDNN, pNN50, and HF HRV were reduced by alcohol, compared to the placebo and control. The 0.1‐Hz HRV index was diminished by alcohol and placebo, suggesting that autonomic regulation can be affected by cognitive expectancy. The 0.1‐Hz HRV index and pNN50 detected changes in arousal during emotional compared to neutral cues, and the 0.1‐Hz HRV index was most sensitive to negative valence. The 0.1‐Hz HRV methodology may be useful for studying the intersection of cognition, emotion, and autonomic regulation.
The pivotal role of news agencies in the context of globalization: a historical approach
Authors: BIELSA ESPERANÇA
Published: May 2008

The global media play a fundamental role in contemporary globalization, making possible instant communication and promoting an experience of global connectedness. The globalization of media communications has deeply shaped the modern journalistic field in the last 150 years and, at the same time, global news organizations have been instrumental in creating the very conditions that have made globalization possible. In this article I explore the relationship between globalization and the media and trace the historical development of the field of global news, examining in detail the role and trajectories of its most important players, the global news agencies, and highlighting significant parallels between nineteenth‐century globalization and the processes that have led to increased global connectedness in the past decades. I also devote some attention to the more recent developments in the field of global news and the appearance of new types of media organizations.
The origin of out‐of‐range pelicans in Europe: wild bird dispersal or zoo escapes?
Authors: JIGUET F. , DOXA A. , ROBERT A.
Published: May 2008

We tested whether spatial and annual patterns of occurrence of out‐of‐range Great White Pelecanus onocrotalus, Dalmatian Pelecanus crispus and Pink‐backed Pelicans Pelecanus rufescens recorded in Europe between 1980 and 2004 supported a natural vagrancy theory. Candidate variables tested were those likely to influence dispersal and escape probability (distance to the usual breeding/wintering range, national captive stock), and wild breeding population sizes and their movements (size of breeding colonies, climate conditions on wintering grounds or during dispersal). Spatial vagrancy patterns supported the hypothesis of wild birds dispersing from their normal range, with decreasing national totals with increasing distance to the usual range for the three species. Annual out‐of‐range numbers of Great White Pelican were predicted by breeding colony size and breeding success in Greece, with a further effect of Sahel rainfall during the previous year. Annual numbers of Dalmatian Pelican were related to the North Atlantic Oscillation index and to breeding success in Greece. Finally, annual numbers of Pink‐backed Pelican were predicted by summer Sahel rainfall, which is known to drive dispersal of the species northwards into the sub‐Sahelian steppes during wet summers there. Hence, annual vagrancy patterns in Europe were well predicted for all three species by population size indices, reproductive success and/or climatic components, which presumably influence survival and/or dispersal. We therefore consider that vagrancy patterns were driven by wild birds, whereas escapes – even if potentially numerous – do not create sufficient ‘noise’ to hide these patterns.
Extracting bird migration information from C‐band Doppler weather radars
Authors: GASTEREN HANS VAN , HOLLEMAN IWAN , BOUTEN WILLEM , LOON EMIEL VAN , SHAMOUN‐BARANES JUDY
Published: May 2008

Although radar has been used in studies of bird migration for 60 years, there is still no network in Europe for comprehensive monitoring of bird migration. Europe has a dense network of military air surveillance radars but most systems are not directly suitable for reliable bird monitoring. Since the early 1990s, Doppler radars and wind profilers have been introduced in meteorology to measure wind. These wind measurements are known to be contaminated with insect and bird echoes. The aim of the present research is to assess how bird migration information can be deduced from meteorological Doppler radar output. We compare the observations on migrating birds using a dedicated X‐band bird radar with those using a C‐band Doppler weather radar. The observations were collected in the Netherlands, from 1 March to 22 May 2003. In this period, the bird radar showed that densities of more than one bird per km3 are present in 20% of all measurements. Among these measurements, the weather radar correctly recognized 86% of the cases when birds were present; in 38% of the cases with no birds detected by the bird radar, the weather radar claimed bird presence (false positive). The comparison showed that in this study reliable altitudinal density profiles of birds cannot be obtained from the weather radar. However, when integrated over altitude, weather radar reflectivity is correlated with bird radar density. Moreover, bird flight speeds from both radars show good agreement in 78% of cases, and flight direction in 73% of cases. The usefulness of the existing network of weather radars for deducing information on bird migration offers a great opportunity for a European‐wide monitoring network of bird migration.
Clinical Outcomes after Failed Renal Transplantation—Does Dialysis Modality Matter?
Authors: Perl Jeffrey , Bargman Joanne M. , Davies Simon J. , Jassal Sarbjit V.
Published: May 2008

Patients returning to dialysis after graft loss (DAGL) are an increasing segment of the end‐stage renal disease (ESRD) population. It is unclear whether patients with previous graft loss have equivalent or reduced survival from the time of restarting dialysis when compared with ESRD patients initiating dialysis for the first time. Moreover, the impact of dialysis modality on the survival of patients returning to DAGL is not known. Studies of patients with transplant graft failure returning to hemodialysis (HD) have suggested decreased survival when compared with transplant‐naïve dialysis patients, yet some studies of patients with graft failure returning to peritoneal dialysis (PD) have demonstrated equivalent survival. Based on these data, it is unclear whether survival differences may exist between the dialysis modalities, and if they do, whether they can be attributed to either differences in patient characteristics or to factors related to the dialysis modalities. For patients starting back onto dialysis, in whom preservation of residual renal function is important, it is also unclear how immunosuppression reduction or transplant nephrectomy may affect survival. In this review, we will summarize the available literature on survival rates of patients returning to DAGL; compare and contrast survival after initiation of HD and PD and discuss what is known about the impact of transplant nephrectomy and the different approaches to immunosuppression reduction. Practical considerations will be discussed with a specific emphasis on patients treated by PD.
Sleep staging and respiratory events in refractory epilepsy patients: Is there a first night effect?
Authors: Selwa Linda M. , Marzec Mary L. , Chervin Ronald D. , Weatherwax Kevin J. , Vaughn Bradley V. , Foldvary‐Schaefer Nancy , Wang Lily , Song Yanna , Malow Beth A.
Published: May 2008

Purpose:  We performed this analysis of possible first night effects (FNEs) on sleep and respiratory parameters in order to evaluate the need for two serial night polysomnograms (PSGs) to diagnose obstructive sleep apnea (OSA) in epilepsy patients.

Methods:  As part of a pilot multicenter clinical trial investigating the effects of treating sleep apnea in epilepsy, two nights of PSG recording were performed for 40 patients with refractory epilepsy and OSA symptoms. Sleep architecture was examined in detail, along with respiratory parameters including apnea/hypopnea index (AHI) and minimum oxygen saturation. Analysis included two‐tailed t‐tests, Wilcox sign rank analysis, and Bland Altman measures of agreement.

Results:  Total sleep time differed between the two nights (night 1,363.8 min + 59.4 vs. 386.3 min + 68.6, p = 0.05). Rapid eye movement (REM) sleep and percentage of REM sleep were increased during night two (night 1: 12.3% + 5.9 vs. night 2: 15.5% + 6.2, p = 0.007), and the total minutes of slow‐wave sleep (SWS) were increased (night 1: 35.6 + 60.7 vs. night 2: 46.4 + 68.1, p = 0.01). No other sleep or respiratory variables differed between the two nights. Given an AHI inclusion criterion of five apneas per hour, the first PSG identified all but one patient with OSA.

Discussion:  Respiratory parameters showed little variability between the first and second nights. Sleep architecture was mildly different between the first and second PSG night. Performing two consecutive baseline PSGs to diagnose OSA may not be routinely necessary in this population.
Different presurgical characteristics and seizure outcomes in children with focal cortical dysplasia type I or II
Authors: Krsek Pavel , Pieper Tom , Karlmeier Anja , Hildebrandt Michelle , Kolodziejczyk Dieter , Winkler Peter , Pauli Elisabeth , Blümcke Ingmar , Holthausen Hans
Published: May 2008

Purpose: Cortical dysplasia (FCD) is a frequent cause of epilepsy in childhood. Two major pathological variants are distinguished, FCD type I and II. The aim of the study was to characterize differences between FCD type I and II with respect to imaging and EEG findings, clinical and neuropsychological presentations, and surgical outcome.

Methods: Forty children with refractory epilepsy and histopathologically confirmed FCD were retrospectively analyzed. FCD type I was identified in 24 and FCD type II in 16 patients.

Results: Characteristic MRI abnormalities in FCD type I included subtle white matter signal changes and regional reduction of the white matter volume. Typical MRI findings in FCD type II were increased cortical thickness, transmantle sign, gray‐white matter junction blurring, fluid‐attenuated inversion recovery (FLAIR) and proton density (PD) gray matter signal changes as well as T1w, and PD white matter signal changes. Continuous EEG slowing was significantly more common in patients with FCD type I. Children with FCD type I presented with lower levels of intelligence and were suffering more often from maladaptive behavior and behavioral disorders. Surgical outcome was significantly worse in the FCD type I group (seizure freedom was achieved in 21% FCD type I patients and in 75% FCD type II subjects, p < 0.001).

Conclusions: Clinically important differences were found in children with distinct histopathological subtypes of FCD. Due to prominent neuropsychological deficits and worse seizure outcome, treatment strategies in FCD type I are more challenging than previously reported and these children should be recognized and specifically addressed within the incoherent group of patients with malformative brain disorders.
Burden of Neuropathic Pain in Indian Patients Attending Urban, Specialty Clinics: Results from a Cross Sectional Study
Authors:   IndINeP Study Group
Published: May 2008

▪ Abstract

Background and Objective:  Recent studies in Western populations have reported high patient burden of neuropathic pain. No data are currently available on the burden of neuropathic pain in Indian patients. Our study evaluated the burden of neuropathic pain in patients attending urban, private‐sector, specialty clinics.

Methods:  This cross‐sectional, observational study surveyed 467 patients with neuropathic pain to assess the burden of pain (pain severity, patient‐reported treatment effectiveness, impact of hypothetical pain relief on overall health rating), burden because of quality of life impairment (EuroQoL health state, pain interference with daily living, sleep and mood disturbances, medication‐related adverse events), and economic burden (treatment cost, impact on employment and productivity). Physicians filled out a clinical case report form to provide information on patient's neuropathic pain disorder and treatment provided. The data were analyzed to assess the overall burden of neuropathic pain.

Results:  Painful diabetic neuropathy was the most common cause of neuropathic pain (72%). Majority (64%) of patients reported moderate to severe pain, and about 50% reported moderate to severe pain‐related interference in activities of daily living. Substantial sleep impairment was reported as compared with general population. About 50% of patients reported co‐morbid mood disorders, while 67% reported medication‐related adverse event in the preceding week. Fifty‐seven per cent of patients reported an adverse impact on their employment status, including 13% who retired early or were unemployed. Among those currently working, 72% reported reduced productivity, including 22% who reported reduced productivity “most” or “all” of the time.

Conclusions:  In Indian patients with access to urban, private‐sector, specialty clinics neuropathic pain (particularly painful diabetic neuropathy) remains a significant medical condition with substantial negative impact on their quality of life. ▪
Structure, regulation and evolution of Nox‐family NADPH oxidases that produce reactive oxygen species
Authors: Sumimoto Hideki
Published: May 2008

NADPH oxidases of the Nox family exist in various supergroups of eukaryotes but not in prokaryotes, and play crucial roles in a variety of biological processes, such as host defense, signal transduction, and hormone synthesis. In conjunction with NADPH oxidation, Nox enzymes reduce molecular oxygen to superoxide as a primary product, and this is further converted to various reactive oxygen species. The electron‐transferring system in Nox is composed of the C‐terminal cytoplasmic region homologous to the prokaryotic (and organelle) enzyme ferredoxin reductase and the N‐terminal six transmembrane segments containing two hemes, a structure similar to that of cytochrome b of the mitochondrial bc1 complex. During the course of eukaryote evolution, Nox enzymes have developed regulatory mechanisms, depending on their functions, by inserting a regulatory domain (or motif) into their own sequences or by obtaining a tightly associated protein as a regulatory subunit. For example, one to four Ca2+‐binding EF‐hand motifs are present at the N‐termini in several subfamilies, such as the respiratory burst oxidase homolog (Rboh) subfamily in land plants (the supergroup Plantae), the NoxC subfamily in social amoebae (the Amoebozoa), and the Nox5 and dual oxidase (Duox) subfamilies in animals (the Opisthokonta), whereas an SH3 domain is inserted into the ferredoxin–NADP+ reductase region of two Nox enzymes in Naegleria gruberi, a unicellular organism that belongs to the supergroup Excavata. Members of the Nox1–4 subfamily in animals form a stable heterodimer with the membrane protein p22phox, which functions as a docking site for the SH3 domain‐containing regulatory proteins p47phox, p67phox, and p40phox; the small GTPase Rac binds to p67phox (or its homologous protein), which serves as a switch for Nox activation. Similarly, Rac activates the fungal NoxA via binding to the p67phox‐like protein Nox regulator (NoxR). In plants, on the other hand, this GTPase directly interacts with the N‐terminus of Rboh, leading to superoxide production. Here I describe the regulation of Nox‐family oxidases on the basis of three‐dimensional structures and evolutionary conservation.
Millisecond dip events in the 2007 RXTE/PCA data of Sco X—1 and the trans-Neptunian object size distribution
Authors: Liu Chih-Yuan , Chang Hsiang-Kuang , Liang Jau-Shian , King Sun-Kun
Published: May 2008

Millisecond dips in the RXTE/PCA archival data of Sco X-1 taken from 1996 to 2002 were reported recently. Those dips were found to be most likely caused by instrumental dead time but may also contain some true astronomical events, which were interpreted as the occultation of X-rays from Sco X-1 by trans-Neptunian objects (TNOs) of 100 m size. Here, we report the results of search for millisecond dip events with the new RXTE/PCA data of Sco X-1 taken in the year 2007. Adopting the same selection criteria as that in the previous study, we found only three dip events in 72-ks data, much fewer than the 107 events found in the 560-ks data taken from 1996 to 2002 reported earlier. The new data provide more detailed information of individual ‘very large events’ (VLEs), which is not available in the old archival data. Although the number of VLEs does not obviously increase during the occurrence of dip events, all the three dip events are coincident in time with VLEs that have no flags set for any of the propane or the six main xenon anodes. It is a strong indication of instrumental effects. No significant dips which might be real occultation by 60–100 m TNOs were observed. With only 72-ks data, however, the previously proposed possibility that about 10 percent of the dip events might not be instrumental still cannot be strictly excluded. Using the absence of those anomalous VLEs as the criterion for identifying non-instrumental dip events, we found, at a lower confidence level, four dip events of duration 8–10 ms in the 72-ks data. Upper limits to the size distribution of TNOs at the small size end are suggested.
Bezafibrate prevents hepatic stellate cell activation and fibrogenesis in a murine steatohepatitis model, and suppresses fibrogenic response induced by transforming growth factor‐β1 in a cultured stellate cell line
Authors: Nakano Shigeru , Nagasawa Tatsuya , Ijiro Tomoyuki , Inada Yoichi , Tamura Toru , Maruyama Kazuyasu , Kuroda Junji , Yamazaki Yoshinobu , Kusama Hiroshi , Shibata Nobuo
Published: May 2008

Aim:  The aim of this study was to investigate the preventive actions of bezafibrate against non‐alcoholic steatohepatitis (NASH), the activation of hepatic stellate cells (HSC), and fibrogenesis by using a model of NASH and an in vitro model.

Methods:  Male KK‐Ay/TaJcl (KK‐Ay) mice were fed a methionine and choline‐deficient (MCD) diet or a MCD diet containing bezafibrate or pioglitazone for 7 weeks, after which biochemical parameters, pathological changes, and hepatic mRNA levels were assessed. An in vitro HSC model was designed by using a previously described RI‐T cell line stimulated by transforming growth factor‐β1 (TGF‐β1).

Results:  MCD diet‐fed KK‐Ay mice developed hepatic steatosis, oxidative stress, inflammation, and hepatic fibrosis. Bezafibrate markedly decreased the hepatic content of triglyceride accumulation of fatty droplets within hepatocytes, and increased the expression of hepatic fatty acid β‐oxidative genes in MCD diet‐fed KK‐Ay mice. Bezafibrate markedly inhibited the increases in the plasma alanine aminotransferase level and hepatic content of thiobarbituric acid‐reactive substances in this model. Moreover, it dramatically reduced hepatic inflammatory changes and fibrosis concomitantly with marked reductions in the mRNA levels for inflammatory cytokine, chemokine, and profibrogenic genes. Importantly, both bezafibrate and pioglitazone markedly reduced the mRNA levels of profibrogenic and fibrogenic genes in TGF‐β1‐stimulated cells.

Conclusion:  Bezafibrate improved hepatic steatosis and potently prevented inflammation, oxidative stress, HSC activation, and fibrogenesis in the liver. Moreover, this study was the first to demonstrate that bezafibrate directly inhibits hepatic fibrogenic response induced by TGF‐β1 in vitro. Hence bezafibrate may be a new therapeutic strategy against NASH and hepatic fibrosis.
Ectopic transplantation of hepatocyte sheets fabricated with temperature‐responsive culture dishes
Authors: Kano Kyoko , Yamato Masayuki , Okano Teruo
Published: May 2008

Aim:  Hepatocyte transplantation to host livers by single cell suspension injection from the portal vein has been clinically successful in cases where the host liver architecture is intact. However, further investigation is still needed to achieve regeneration of the liver architecture when the host liver is destroyed, since single cell suspension injection often results in the formation of small hepatocyte colonies or islands. We show a hepatocyte transplantation strategy to ectopic sites.

Methods:  Primary hepatocytes isolated from green fluorescent protein (GFP)‐transgenic rats were cultured on temperature‐responsive culture dishes. After harvest as intact cell sheets, triple‐layered cell sheets were transplanted over the superficial caudal epigastric artery and vein of athymic rats which had operation of 70% partial hepatectomy.

Results:  The transplanted hepatocytes were integrated to host tissue with a laminar cell arrangement at transplanted sites within one week after surgery. But the transplanted hepatocytes were hardly detected four weeks after transplantation, when the partially hepatectomized host liver was completely regenerated. GFP‐positive bile duct‐like tubes and functional blood vessels were observed.

Conclusion:  These results imply the usefulness of hepatocyte sheets in ectopic transplantation, as well as the need of trophic factors for hepatocyte survival.
Calprotectin is released from human skeletal muscle tissue during exercise
Authors: Mortensen Ole Hartvig , Andersen Kasper , Fischer Christian , Nielsen Anders Rinnov , Nielsen Søren , Åkerström Thorbjörn , Aastrøm Maj‐brit , Borup Rehannah , Pedersen Bente Klarlund
Published: May 2008

Skeletal muscle has been identified as a secretory organ. We hypothesized that IL‐6, a cytokine secreted from skeletal muscle during exercise, could induce production of other secreted factors in skeletal muscle. IL‐6 was infused for 3 h into healthy young males (n= 7) and muscle biopsies obtained at time points 0, 3 and 6 h in these individuals and in resting controls. Affymetrix microarray analysis of gene expression changes in skeletal muscle biopsies identified a small set of genes changed by IL‐6 infusion. RT‐PCR validation confirmed that S100A8 and S100A9 mRNA were up‐regulated 3‐fold in skeletal muscle following IL‐6 infusion compared to controls. Furthermore, S100A8 and S100A9 mRNA levels were up‐regulated 5‐fold in human skeletal muscle following cycle ergometer exercise for 3 h at ∼60% of in young healthy males (n= 8). S100A8 and S100A9 form calprotectin, which is known as an acute phase reactant. Plasma calprotectin increased 5‐fold following acute cycle ergometer exercise in humans, but not following IL‐6 infusion. To identify the source of calprotectin, healthy males (n= 7) performed two‐legged dynamic knee extensor exercise for 3 h with a work load of ∼50% of peak power output and arterial–femoral venous differences were obtained. Arterial plasma concentrations for calprotectin increased 2‐fold compared to rest and there was a net release of calprotectin from the working muscle. In conclusion, IL‐6 infusion and muscle contractions induce expression of S100A8 and S100A9 in skeletal muscle. However, IL‐6 alone is not a sufficient stimulus to facilitate release of calprotectin from skeletal muscle.
Novel aspects of the molecular mechanisms controlling insulin secretion
Authors: Eliasson Lena , Abdulkader Fernando , Braun Matthias , Galvanovskis Juris , Hoppa Michael B. , Rorsman Patrik
Published: May 2008

Pancreatic β‐cells secrete insulin by Ca2+‐dependent exocytosis of secretory granules. β‐cell exocytosis involves SNARE (soluble NSF‐attachment protein receptor) proteins similar to those controlling neurotransmitter release and depends on the close association of L‐type Ca2+ channels and granules. In most cases, the secretory granules fuse individually but there is ultrastructural and biophysical evidence of multivesicular exocytosis. Estimates of the secretory rate in β‐cells in intact islets indicate a release rate of ∼15 granules per β‐cell per second, 100‐fold higher than that observed in biochemical assays. Single‐vesicle capacitance measurements reveal that the diameter of the fusion pore connecting the granule lumen with the exterior is ∼1.4 nm. This is considerably smaller than the size of insulin and membrane fusion is therefore not obligatorily associated with release of the cargo, a feature that may contribute to the different rates of secretion detected by the biochemical and biophysical measurements. However, small molecules like ATP and GABA, which are stored together with insulin in the granules, are small enough to be released via the narrow fusion pore, which accordingly functions as a molecular sieve. We finally consider the possibility that defective fusion pore expansion accounts for the decrease in insulin secretion observed in pathophysiological states including long‐term exposure to lipids.
GABAergic signalling to adult‐generated neurons
Authors: Markwardt Sean , Overstreet‐Wadiche Linda
Published: May 2008

New neurons are continuously generated in discrete regions of the adult brain. In the hippocampus, newly generated cells undergo a step‐wise progression of maturation that is regulated at multiple stages by a variety of physiological and pathological stimuli. Neural progenitors and newborn neurons initially receive exclusively GABAergic synaptic input, and accumulating evidence suggests that depolarizing actions of GABA contribute to activity‐dependent regulation. Here we provide a brief overview of GABAergic signalling to newborn neurons in the hippocampus and describe how it regulates adult neurogenesis.
Structural Basis of Trans-Inhibition in a Molybdate/Tungstate ABC Transporter
Authors: Gerber Sabina , Comellas-Bigler Mireia , Goetz Birke A. , Locher Kaspar P.
Published: May 2008

Transport across cellular membranes is an essential process that is catalyzed by diverse membrane transport proteins. The turnover rates of certain transporters are inhibited by their substrates in a process termed trans-inhibition, whose structural basis is poorly understood. We present the crystal structure of a molybdate/tungstate ABC transporter (ModBC) from
Methanosarcina acetivorans
in a trans-inhibited state. The regulatory domains of the nucleotide-binding subunits are in close contact and provide two oxyanion binding pockets at the shared interface. By specifically binding to these pockets, molybdate or tungstate prevent adenosine triphosphatase activity and lock the transporter in an inward-facing conformation, with the catalytic motifs of the nucleotide-binding domains separated. This allosteric effect prevents the transporter from switching between the inward-facing and the outward-facing states, thus interfering with the alternating access and release mechanism.
Benomyl and acephate applications increase survival of sugar maple seedlings during their first growing season in northern Pennsylvania
Authors: Stanosz G.R.
Published: May 2008

A study was conducted to determine the contributions of pathogenic fungi and insects to the mortality of sugar maple (Acersaccharum Marsh.) seedlings during their first season of growth. Replicated plots were located in four northern Pennsylvania stands in which the anthracnose pathogen, Disculacampestris (Pass.) von Arx, and the pear thrips, Taeniothripsinconsequens (Uzel), were associated with sugar maple seedlings. Survival was quantified for new seedlings treated with water (control), the systemic fungicide benomyl, the systemic insecticide acephate, or both, during May through August 1990. Treatment affected mean survival (p < 0.001), which was approximately 2–3 times higher in plots treated with benomyl and acephate than in plots treated with water only. Treatment with the fungicide, insecticide, or both also generally increased the percentage of seedlings bearing leaves (p < 0.001), the number of leaves per seedling bearing leaves (p < 0.001), shoot weight (p = 0.015), and root weight (p = 0.018). Diseases caused by fungi and damage from insects may be the major factors affecting survival of new sugar maple seedlings.
Recent mortality and decline in mature Abiesamabilis: the interaction between site factors and tephra deposition from Mount St. Helens
Authors: Segura Gerardo , Brubaker Linda B. , Franklin Jerry F. , Hinckley Thomas M. , Maguire Douglas A. , Wright Gary
Published: May 2008

Patterns of decline of mature and old-growth stands of Abiesamabilis (Dougl.) Forbes (Pacific silver fir) induced by tephra deposition from the 1980 eruption of Mount St. Helens were analyzed at the landscape level using discriminant and least squares regression analysis. From an array of environmental and biological factors, only the thickness of fine A3 tephra deposit, elevation, and the relative dominance of A. amabilis in a stand showed significant effects on decline. Stand decline, a mean value of the decline conditions of individual trees in a stand, increased with increasing amounts of A3 tephra and decreased with increasing elevation and relative dominance of A. amabilis. Elevation and relative dominance of A. amabilis were positively correlated, complicating the interpretation of each variable alone; we suspect that each individually represents conditions that influenced the vigor A. amabilis predisposing it and (or) contributing to the initial tephra-induced stress and, therefore, affecting its survival and recovery.
Genetic variation in 26 populations of Racospermaauriculiforme and Racospermamangium using allozymes
Authors: Khasa P.D. , Cheliak W.M. , Bousquet J.
Published: May 2008

Racospermaauriculiforme (Cunn. ex Benth.) Pedley and Racospermamangium (Willd.) Pedley are two fast-growing multipurpose leguminous species that have great potential for reforestation in the subhumid and humid tropics. The level and distribution of genetic variability were evaluated among and within 13 populations of each species at 18 loci encoding 10 enzymes, using starch gel electrophoresis. At the population level, the mean number of alleles per locus, the mean percentage of polymorphic loci, and mean expected heterozygosity were, respectively, 1.9, 52.1%, and 0.122 for R. auriculiforme, and 1.5, 24.3%, and 0.064 for R. mangium. Therefore, R. mangium appeared genetically depauperate compared with R. auriculiforme. The proportion of the total genetic diversity that resided among populations in R. auriculiforme (18%) was twice that in R. mangium (9%). No linear relationships were detected between genetic and geographic distances among populations. Cluster analysis of Nei's genetic distances and discriminant analysis did not show any significant geographic pattern of population differentiation for R. mangium. These same analyses revealed two distinct clusters of populations for R. auriculiforme, one in Queensland, Australia, and Papua New Guinea, and the other in the Northern Territory of Australia and Indonesia. For both taxa, seed of unknown origin of some introduced populations in Zaire and Congo could be identified. The genetic distance between the two species (D = 0.097) was, as expected, much larger than the average intraspecific genetic distance derived from comparisons of conspecific populations (D = 0.034 for R. auriculiforme and D = 0.007 for R. mangium). However, the amplitude of the interspecific genetic distance calculated is representative of divergence levels usually observed among subspecific taxa. Based on this, and the lower levels of genetic diversity found in R. mangium, it is suggested that R. mangium derived recently from R. auriculiforme.
Needle loss as a mechanism of winter drought avoidance in boreal conifers
Authors: Berg Edward E. , Chapin III F. Stuart
Published: May 2008

Xylem (water) pressure potential was measured through one winter in evergreen black spruce (Piceamariana (Mill.) B.S.P.) and deciduous larch (Larixlaricina (Du Roi) K. Koch) in Fairbanks, Alaska. Larch values averaged about −1.0 MPa, with occasional dips to −1.5 MPa. Black spruce showed similar values until May, when values dropped to −2.5 MPa. Regression models indicate that desiccation of black spruce responds primarily to cumulative vapor pressure deficit (drought), which becomes severe as spring daylight rapidly increases (R2 = 80%). In larch, the effect of cumulative drought was offset by increased spring air temperatures.
Allozyme variation within and among cultivated varieties of sweet chestnut (Castaneasativa)
Authors: Flneschi S. , Malvolti M.E. , Morgante M. , Vendramin G.G.
Published: May 2008

Sweet chestnut (Castaneasativa Mill.) is a species that has been cultivated and propagated through grafting for a long time in Italy and Southern European countries. The genetic variability within and among different varieties was analyzed by means of starch gel electrophoresis. Twenty cultivated varieties originating from three different areas located in northern, central, and southern Italy, were analyzed at six polymorphic enzyme gene loci. Our results show a relatively high degree of homogeneity both among individuals of the same variety and among varieties of the same area; on the other hand, high values of genetic distance were found among different geographic areas. The agamic propagation method of this species may have caused a reduction of the genetic diversity within varieties. The causes and consequences of the loss of genetic variation in these varieties are discussed.
Red pine abundance: current climatic control and responses to future warming
Authors: Flannigan M.D. , Woodward F.I.
Published: May 2008

This study investigated the relationship between climatic variables and the abundance of red pine (Pinusresinosa Ait.). Two aspects of this climate–abundance relationship were addressed. First, a model was developed to fit the present day range and abundance of red pine using available climatic variables in the expectation of better understanding the processes controlling distribution. Second, general circulation models were used to explore the implications of a 2 × CO2(greenhouse warming) environment on the range and abundance of red pine. Using a response surface, growing degree-days (base 10 °C), and precipitation explained 54% of the variance in an independent data set of red pine volume per unit area. Possible explanations for the present day boundaries of red pine are competition for the southern limit, insufficient moisture for the southwestern limit, and insufficient warmth during the growing season at the northern limit. The greenhouse warming simulation suggested a dramatic northeastward shift of 600–800 km in the potential range of red pine and a decrease in total area, but it also suggested higher volumes per unit area.
Above- and below-ground biomass and fine roots of 4-year-old hybrids of Populustrichocarpa × Populusdeltoides and parental species in short-rotation culture
Authors: Heilman P.E. , Ekuan G. , Fogle D.
Published: May 2008

Mean annual aboveground leafless biomass production averaged 14.8, 11.4, and 24.3 Mg•ha−1•year−1 at harvest at 4 years of age for Populustrichocarpa Torr. & Gray, Populusdeltoides Marsh., and P. trichocarpa × P. deltoides hybrids, respectively. These trees were planted at 1 × 1 m spacing on a medium- to coarse-textured alluvial soil in western Washington. Branches accounted for 13.2–20.3% of the aboveground weight. Total weight of stumps and coarse roots at harvest varied from 12.3 to 29.6 Mg•ha−1, or 22–33% of the weight of aboveground leafless biomass. Small and fine roots sampled to a depth of 3.17 m using soil cores amounted to an additional 6.6–11 Mg•ha−1 of roots. Stumps and all roots as a ratio of aboveground biomass (root/shoot ratio) ranged from 0.34 to 0.42, with hybrids accounting for the entire range of values present. Mass of the fine roots (less than 0.5 mm diameter) ranged from 4.0 to 6.5 Mg•ha−1, or an average of 6.8% of the aboveground biomass. The smallest of the fine roots measured 0.06 mm in diameter. Specific root length of fine roots averaged 50.7 m•g−1 for P. deltoides, 42 m•g−1 for P. trichocarpa, and 30–47 m•g−1 for hybrids. Total length of fine roots to a depth of 3.17 m ranged from 179 000 to 284 000 km•ha−1. Density of fine roots by length per unit soil volume was greatest at the surface with the range of means for clones in the top 0.18 m being 2.4–6.3 cm•cm−3; at 1.0–3.17 m soil depth, density was 0.02–0.6 cm•cm−3. For two of the hybrid clones, the density of fine roots at the soil surface was half that of the other clones. The distribution of fine roots in the stratified soil profile was correlated with soil depth, Kjeldahl N, and organic matter, with the latter two parameters showing the highest coefficients of determination (0.73 and 0.71, respectively). In the more sandy but layered subsoil (0.36–3.17 m depth), soil depth, Kjeldahl N, and sand content were most strongly correlated with fine root density, with depth and sand content giving the highest coefficients of determination (0.32 and 0.31, respectively). Roots in sandy subsoil were coarser and much less branched than in adjacent finer textured layers.
Behaviour of 137Cs from Chernobyl fallout in a Scots pine canopy in southern Finland
Authors: Nygren Pekka , Hari Pertti , Raunemaa Taisto , Kulmala Markku , Luokkanen Sinikka , Holmberg Maria , Nikinmaa Eero
Published: May 2008

The behaviour of 137Cs from the Chernobyl nuclear power plant accident in the Ukraine on 26 April 1986 was monitored during a 3-year period in the canopy of a young Scots pine (Pinussylvestris L.) stand in southern Finland. Needle samples were collected from the same whorls on 13 sample trees marked at the beginning of the study. The 137Cs activity of throughfall water was determined in summer 1986. The oldest needles at the time of the radioactive deposition (formed in 1983) had the highest l37Cs activity (20 000 Bq/kg) in June 1986, when the monitoring was started, 58 days after deposition. About 50% lower 137Cs activity was observed in the needles formed in 1984 and 1985, and an even lower activity of 3050 Bq/kg in the needles formed in 1986 following the incident. During the summer of 1986, the 137Cs activity of the whole canopy decreased from 106 000 to 42 500 kBq/ha, corresponding to a weathering half-life of 72 days. Washout by throughfall accounted for 79% of the decrease, while the rest was mainly due to the gradual shedding of the highly contaminated 1983 needles. The needles formed in the summers of 1987 and 1988 had rather high 137Cs activities of 2700 and 4800 Bq/kg, respectively. The reduction in the 137Cs activity of the canopy was considerably less in 1987 and 1988, with weathering half-lives of 435 and 242 days, respectively. The total 137Cs activity of the canopy was still 13 500 kBq/ha on 20 October 1988, which was 896 days after deposition. An increase in the 137Cs activity was observed in the autumns 1987 and 1988, and to a lesser degree in the autumn of 1986, a time of year when needle potassium concentrations normally tend to increase. It was concluded that the Chernobyl 137Cs had become mixed with the chemically analogous K, and was recirculated within the trees together with K.
Role of endothelin receptors on basal and endothelin-1-stimulated lung myofibroblast proliferationThis article is one of a selection of papers published in the special issue (part 1 of 2) on Forefronts in Endothelin.
Authors: Préfontaine Annick , Calderone Angelino , Dupuis Jocelyn
Published: May 2008

Proliferation of myofibroblasts (MYF) contributes to numerous lung disorders. Endothelin-1 (ET-1) production is increased in various lung diseases and could contribute to lung remodelling. The respective roles of ETAand ETBreceptors (ETA-R, ETB-R) and the role of endogenous ET-1 production by lung MYF on proliferation of MYF remain uncertain. Rat lung MYF were isolated and3H-thymidine and3H-leucine incorporation assays were completed in the presence of a selective ETA-R antagonist, a selective ETB-R antagonist, or a combination of both. Receptor expression was evaluated by confocal imaging, and ET-1 levels were measured by ELISA. Confocal microscopy revealed abundant ETA-R and ETB-R expression on lung MYF. ET-1 (10 nmol/L) stimulated MYF proliferation and protein synthesis through PI3-kinase and p38 pathways. Although neither selective ETA-R blockade (BQ-123, 1 μmol/L) nor selective ETB-R blockade (BQ-788, 1 μmol/L) alone inhibited proliferation or protein synthesis, their combination almost completely abolished ET-1 mitogenic effect. Surprisingly, basal MYF proliferation was increased by selective blockade of either ETA-R or ETB-R alone, but not by dual blockade. ET-1 levels were not affected by the antagonists. Our findings indicate that both the ETA-R and the ETB-R regulate basal and stimulated lung MYF proliferation and suggest possible interactions between the receptors.
Additional lack of iNOS attenuates diastolic dysfunction in aged ET-1 transgenic miceThis article is one of a selection of papers published in the special issue (part 1 of 2) on Forefronts in Endothelin.
Authors: Kalk Philipp , Westermann Dirk , Herzfeld Sophia , Relle Katharina , Pfab Thiemo , Bauer Christian , Tschöpe Carsten , Stasch Johannes-Peter , Hocher Berthold
Published: May 2008

Endothelin-1 (ET-1) exhibits potent proinflammatory and profibrotic properties. Moreover, inflammation is a potent stimulus for inducible NO synthase (iNOS), which has been shown to contribute to cardiac injury. We thus hypothesized that ET-1-induced cardiac injury is attenuated by concomitant lack of iNOS. We established crossbred animals of ET-1 transgenic mice (ET+/+) and iNOS knockout mice (iNOS−/−). At 13 months of age, mice were allocated according to their genotype to one of 4 study groups: wild type (WT) controls (n = 8); ET-1 transgenic (ET+/+) mice (n = 10); iNOS knockout (iNOS−/−) mice (n = 7); and crossbred (ET+/+ iNOS−/−) mice (n = 15). Left ventricular function was determined in vivo by using a tip catheter. Animals were subsequently euthanized and hearts were harvested for weight assessment and histologic evaluation. No cardiac hypertrophy was present, as evidenced by similar mean cardiac weight and myocyte diameter in all groups. Cardiac perivascular fibrosis was significantly increased in ET+/+ and iNOS−/− groups versus WT, whereas ET+/+ iNOS−/− mice did not differ from WT. Regarding left ventricular function, plasma B-type natriuretic peptide was elevated in ET+/+ and iNOS−/− mice, but again in crossbred animals this effect was blunted. Heart catheterization revealed a significantly increased stiffness constant in both ET-overexpressing groups versus WT, but this increase was significantly attenuated in the ET+/+iNOS−/− group versus the ET+/+ group. Parameters indicating systolic heart failure (EF, cardiac output), however, were not different between all study groups. Our study demonstrates that ET transgenic mice develop left ventricular stiffening with subsequent diastolic dysfunction in a slow, age-dependent manner. Additional knock out of iNOS significantly attenuates cardiac injury. We thus conclude that ET-1-induced cardiac injury is at least partially mediated by iNOS.
Role of the ETBreceptor in retinal ganglion cell death in glaucomaThis article is one of a selection of papers published in the special issue (part 1 of 2) on Forefronts in Endothelin.
Authors: Krishnamoorthy Raghu R. , Rao Vidhya R. , Dauphin Rachel , Prasanna Ganesh , Johnson Christina , Yorio Thomas
Published: May 2008

Recent observations suggest that the vasoactive peptide endothelin-1 (ET-1) may be an important contributor to the etiology of glaucoma. ET-1 administration has been shown to produce optic nerve axonal loss and apoptosis of retinal ganglion cells. Ocular ET-1 levels are elevated in aqueous humor in response to elevated intraocular pressure both in glaucoma patients and in animal models of glaucoma; however, the precise mechanisms by which ET-1 mediates glaucomatous optic neuropathy are not clear. Presently we report that ET-1-mediated apoptosis was markedly attenuated in ETBreceptor-deficient rats, suggesting a key role for ETBreceptors in apoptosis of retinal ganglion cells by ET-1 treatment. Using virally transformed rat retinal ganglion cells (RGC-5 cells), we found that ET-1 (100 nmol/L) treatment produced apoptotic changes in these cells that was determined by flow cytometric analyses, release of mitochondrial cytochrome c to the cytosol, and increased phosphorylation of c-Jun N-terminal kinase. Pretreatment with the ETB-receptor antagonist BQ788 (1 μmol/L) was able to significantly attenuate ET-1-mediated apoptosis in RGC-5 cells. ET-1-mediated apoptotic changes in RGC-5 cells were associated with ETB-receptor activation and were accompanied by a significant upregulation of ETB-receptor expression. These studies suggest that ocular ET-1 acts through ETBreceptors to mediate apoptosis of retinal ganglion cells, a key event in glaucoma and related optic neuropathies.
ON SIMPLICITY OF BOUNDED PSEUDOALGEBRAICALLY CLOSED STRUCTURES
Authors: POLKOWSKA O. P. NICHOLAS MARIE
Published: May 2008

Bounded PAC substructures of models of stable theory T are generalizations of bounded PAC fields and bounded PAC beautiful pairs generalize Poizat's beautiful pairs. Both notions were introduced in the authors Ph.D. thesis. In this paper, we prove that under the assumption that the PAC property is first order for T, the theory of any bounded PAC structure is simple. Moreover, if the PAC property is first order for T and T does not have the finite cover property, then the theory of any bounded PAC beautiful pair is simple. We, also, give a characterization of dividing in both cases.