bluuebunny/crossref_metadata_2025_split huggingface dataset:
An active nitrogen cycle on Mars sufficient to support a subsurface biosphere
Authors: Boxe C.S. , Hand K.P. , Nealson K.H. , Yung Y.L. , Saiz-Lopez A. 
Published: January 2012

AbstractMars' total atmospheric nitrogen content is 0.2 mbar. One-dimensional (1D) photochemical simulations of Mars' atmosphere show that nitric acid (HNO3(g)), the most soluble nitrogen oxide, is the principal reservoir species for nitrogen in its lower atmosphere, which amounts to a steady-state value of 6×10−2kg or 4 moles, conditions of severe nitrogen deficiency. Mars could, however, support ∼1015kg of biomass (∼1 kg N m−2) from its current atmospheric nitrogen inventory. The terrestrial mass ratio of nitrogen in biomass to that in the atmosphere is ∼10−5; applying this ratio to Mars yields ∼1010kg of total biomass – also, conditions of severe nitrogen deficiency. These amounts, however, are lower limits as the maximum surface-sink of atmospheric nitrogen is 2.8 mbar (9×1015kg of N), which indicates, in contradistinction to the Klingleret al. (1989), that biological metabolism would not be inhibited in the subsurface of Mars. Within this context, we explore HNO3deposition on Mars' surface (i.e. soil and ice-covered regions) on pure water metastable thin liquid films. We show for the first time that the negative change in Gibbs free energy increases with decreasing HNO3(g) (NO3−(aq)) in metastable thin liquid films that may exist on Mars' surface. We also show that additional reaction pathways are exergonic and may proceed spontaneously, thus providing an ample source of energy for nitrogen fixation on Mars. Lastly, we explore the dissociation of HNO3(g) to form NO3−(aq) in metastable thin liquid films on the Martian surface via condensed phase simulations. These simulations show that photochemically produced fixed nitrogen species are not only released from the Martian surface to the gas-phase, but more importantly, transported to lower depths from the Martian surface in transient thin liquid films. A putative biotic layer at 10 m depth would produce HNO3and N2sinks of −54 and −5×1012molecules cm−2s−1, respectively, which is an ample supply of available nitrogen that can be efficiently transported to the subsurface. The downward transport as well as the release to the atmosphere of photochemically produced fixed nitrogen species (e.g. NO2−, NO and NO2) suggests the existence of a transient but active nitrogen cycle on Mars.
Identification of signal transduction pathways involved in the formation of platelet subpopulations upon activation
Authors: Topalov Nikolai N. , Kotova Yana N. , Vasil’ev Sergey A. , Panteleev Mikhail A. 
Published: January 2012

SummaryPlatelets are formed elements of blood. Upon activation, they externalize phosphatidylserine, thus accelerating membrane‐dependent reactions of blood coagulation. Activated platelets form two subpopulations, only one of which expresses phosphatidylserine. This study aimed to identify signalling pathways responsible for this segregation. Gel‐filtered platelets, intact or loaded with calcium‐sensitive dyes, were activated and labelled with annexin V and antibodies, followed by flow cytometric analysis. Calcium Green and Fura Red dyes were compared, and only the latter was able to detect calcium level differences in the platelet subpopulations. Phosphatidylserine‐positive platelets produced by thrombin had stably high intracellular calcium level; addition of convulxin increased and stabilized calcium level in the phosphatidylserine‐negative subpopulation. PAR1 agonist SFLLRN also induced calcium rise and subpopulation formation, but the resulting platelets were not coated with alpha‐granule proteins. Adenylatecyclase activator forskolin inhibited phosphatidylserine‐positive platelets formation several‐fold, while its inhibitor SQ22536 had no effect. This suggests that adenylatecyclase inactivation is necessary, but not rate‐limiting, for subpopulation segregation. Inhibition of mitogen‐activated protein kinase kinase (U0126) and glycoprotein IIb‐IIIa (Monafram®) was without effect, whereas inhibitors of phosphatidylinositol 3‐kinase (wortmannin) and Src tyrosine kinase (PP2) decreased the procoagulant subpopulation threefold. These data identify the principal signalling pathways controlling platelet heterogeneity.
Do neuro‐humoral signaling molecules participate in colorectal carcinogenesis/cancer progression?
Authors: Delbro Dick S. 
Published: January 2012

AbstractSignaling molecules in the gastrointestinal (GI) tract, as released from intrinsic, or extrinsic neurons, or from local endocrine cells may serve as positive or negative growth factors, and it has been suggested that such could participate also in colorectal carcinogenesis/cancer progression. Sporadic colorectal cancer arises from an initially benign adenoma, which, in turn, develops from the stem cell compartment, located in the bottom of the crypts of the colorectal mucosa. It was recently demonstrated in rat that intrinsic denervation of the colon appeared to be protective against chemically induced carcinogenesis. Of the various GI signaling molecules, noradrenaline (NA) and substance P (SP) may be of particular importance as growth factors involved in colorectal cancer. In the current issue of Neurogastroenterology and Motility, Graf et al. demonstrate that in benign, human colon polyps, there was a loss of innervation compared with adjacent mucosa, affecting efferent, noradrenergic, as well as sensory, SP‐ergic fibers, while there was an increase in SP‐immunoreactive non‐neuronal cells in the polyps. The results obtained could suggest that loss of mucosal innervation, due to e.g. luminal, pro‐inflammatory stimuli, could result in unbalanced pro‐tumorigenic stimulation of the stem cell region by non‐neuronal SP. The current findings may be important for the further understanding of the development of sporadic colorectal cancer.
The bias in current measures of gestational weight gain
Authors: Hutcheon Jennifer A. , Bodnar Lisa M. , Joseph K. S. , Abrams Barbara , Simhan Hyagriv N. , Platt Robert W. 
Published: January 2012

SummaryHutcheon JA, Bodnar LM, Joseph KS, Abrams B, Simhan HN, Platt RW. The bias in current measures of gestational weight gain. Paediatric and Perinatal Epidemiology 2012; 26: 109–116.Conventional measures of gestational weight gain (GWG), such as average rate of weight gain, are likely to be correlated with gestational duration. Such a correlation could introduce bias to epidemiological studies of GWG and adverse perinatal outcomes because many perinatal outcomes are also correlated with gestational duration. This study aimed to quantify the extent to which currently used GWG measures may bias the apparent relationship between maternal weight gain and risk of preterm birth. For each woman in a provincial perinatal database registry (British Columbia, Canada, 2000–2009), a total GWG was simulated such that it was uncorrelated with risk of preterm birth. The simulation was based on serial antenatal GWG measurements from a sample of term pregnancies. Simulated GWGs were classified using three approaches: total weight gain (kg), average rate of weight gain (kg/week) or adequacy of GWG in relation to Institute of Medicine recommendations. Their association with preterm birth ≤32 weeks was explored using logistic regression. All measures of GWG induced an apparent association between GWG and preterm birth ≤32 weeks even when, by design, none existed. Odds ratios in the lowest fifths of each GWG measure compared with the middle fifths ranged from 4.4 [95% confidence interval (CI) 3.6, 5.4] (total weight gain) to 1.6 [95% CI 1.3, 2.0] (Institute of Medicine adequacy ratio). Conventional measures of GWG introduce serious bias to the study of maternal weight gain and preterm birth. A new measure of GWG that is uncorrelated with gestational duration is needed.
Occurrence of Hymenoscyphus pseudoalbidus on infected ash logs
Authors: Husson C. , Caël O. , Grandjean J. P. , Nageleisen L. M. , Marçais B. 
Published: January 2012

Ash decline induced by Hymenoscyphus pseudoalbidus is an emerging disease that severely affects Fraxinus excelsior stands in Europe. There has been an invasive spread of the disease from east to west in Europe over the last decade. Wood discoloration on infected trunks has been reported, but few data are available on the involvement of H. pseudoalbidus in such symptoms. Transport and trade of ash logs could introduce the pathogen into disease‐free areas and therefore accelerate its dissemination. The aim of this study was to assess the prevalence and severity of H. pseudoalbidus in ash logs in infested areas located in the northeast of France and to clarify the role of secondary pathogens in ash decline. The results showed that prevalence of H. pseudoalbidus on collar lesions was high in the study area. The pathogen was able to produce conidia from infected wood. Thus, export of ash logs could represent a potential risk for spreading the disease. Involvement of Armillaria spp. in the decline process was confirmed, while no Phytophthora‐induced collar lesions were found. Studying both disease prevalence and the age of callus tissues surrounding collar lesions in 60 ash stands enabled the origin of the disease in the study area to be determined.
Tomato chlorosis virus in pepper: prevalence in commercial crops in southeastern Spain and symptomatology under experimental conditions
Authors: Fortes I. M. , Moriones E. , Navas‐Castillo J. 
Published: January 2012

Tomato chlorosis virus (ToCV), a member of the genus Crinivirus (family Closteroviridae), has been present in Spain since at least 1997, causing annual epidemics of yellowing in protected tomato crops. In 1999, sweet pepper plants exhibiting stunting and symptoms of interveinal yellowing and mild upward curling in the leaves, were found to be infected with ToCV in a greenhouse heavily infested with the whitefly Bemisia tabaci in the province of Almería, southeastern Spain. This study investigated the prevalence of ToCV in tomato and pepper crops in the major growing areas of southeastern Spain (Murcia, Almería and Málaga provinces) over a 3‐year period. In addition, an experimental system was developed for ToCV inoculation using B. tabaci as a vector, which allowed analysis of susceptibility of different pepper cultivars to the virus. The disease syndrome and yield losses induced by ToCV in pepper were also studied under experimental conditions, confirming severe yield reduction in infected plants.
Alteration of physiological parameters of Austrocedrus chilensis by the pathogen Phytophthora austrocedrae
Authors: Vélez M. L. , Silva P. V. , Troncoso O. A. , Greslebin A. G. 
Published: January 2012

The effect of the pathogen Phytophthora austrocedrae on tree physiology of Austrocedrus chilensis in Patagonia was studied in a 4‐week study. In the first week, stem‐inoculated saplings showed a significant decrease in photosynthesis (A) without alteration of stomatal conductance (gs) or stem‐specific hydraulic conductivity (Ks). From the second week on, progressive decreases in A, gs and Ks were observed, concomitantly with development of significant stem lesions. Water use efficiency (WUE) increased in the second week and declined progressively from the third week. Hyphae and resinous materials were observed in tracheids and rays below lesions. Necrosis of parenchyma ray cells and blockage of tracheids torus were observed. Healthy xylem showed no resinous materials or tracheid blockage, but abundant starch in rays, which was absent in altered xylem. The culture filtrate (CF) of the pathogen was shown to induce changes in extracellular pH and conductivity, and increased necrosis in tissues of leaves and stem challenged with CF in vitro. Similar results were obtained in leaf tissues of the inoculated saplings in vivo. CF injection into xylem of saplings induced a decline in A and disturbance of leaf tissue integrity, without altering gs, WUE or Ks. The decrease of A correlated with changes in tissue integrity. A possible mechanism of A. chilensis decline induced by P. austrocedrae is discussed.
Clusters of leprosy transmission and of late diagnosis in a highly endemic area in Brazil: focus on different spatial analysis approaches
Authors: Alencar Carlos H. , Ramos Alberto N. , dos Santos Emerson S. , Richter Joachim , Heukelbach Jorg 
Published: January 2012

AbstractObjective  The Brazilian National Hansen’s Disease Control Program recently identified clusters with high disease transmission. Herein, we present different spatial analytical approaches to define highly vulnerable areas in one of these clusters.Method  The study area included 373 municipalities in the four Brazilian states Maranhão, Pará, Tocantins and Piauí. Spatial analysis was based on municipalities as the observation unit, considering the following disease indicators: (i) rate of new cases/100 000 population, (ii) rate of cases <15 years/100 000 population, (iii) new cases with grade‐2 disability/100 000 population and (iv) proportion of new cases with grade‐2 disabilities. We performed descriptive spatial analysis, local empirical Bayesian analysis and spatial scan statistic.Results  A total of 254 (68.0%) municipalities were classified as hyperendemic (mean annual detection rates >40 cases/100 000 inhabitants). There was a concentration of municipalities with higher detection rates in Pará and in the center of Maranhão. Spatial scan statistic identified 23 likely clusters of new leprosy case detection rates, most of them localized in these two states. These clusters included only 32% of the total population, but 55.4% of new leprosy cases. We also identified 16 significant clusters for the detection rate <15 years and 11 likely clusters of new cases with grade‐2. Several clusters of new cases with grade‐2/population overlap with those of new cases detection and detection of children <15 years of age. The proportion of new cases with grade‐2 did not reveal any significant clusters.Conclusions  Several municipality clusters for high leprosy transmission and late diagnosis were identified in an endemic area using different statistical approaches. Spatial scan statistic is adequate to validate and confirm high‐risk leprosy areas for transmission and late diagnosis, identified using descriptive spatial analysis and using local empirical Bayesian method. National and State leprosy control programs urgently need to intensify control actions in these highly vulnerable municipalities.
The diagnostic yield of CT‐guided percutaneous lung biopsy in solid organ transplant recipients
Authors: Hsu Joe L. , Kuschner Ware G. , Paik Jane , Bower Natalie , Vazquez Guillamet Maria C. , Kothary Nishita 
Published: January 2012

Hsu JL, Kuschner WG, Paik J, Bower N, Guillamet MCV, Kothary N. The diagnostic yield of CT‐guided percutaneous lung biopsy in solid organ transplant recipients.Abstract:  Background:  Despite the widespread use of computed tomography (CT)‐guided percutaneous lung biopsy (PLB) in immunocompetent patients, the diagnostic yield and safety in solid organ transplant (SOT) recipients is unknown. The purpose of this investigation was to determine the test performance of CT‐PLB in SOT recipients.Methods:  We performed a 10‐yr single‐center, retrospective analysis among heart, lung, kidney, and liver transplant recipients. We included all adult patients who underwent a PLB of a parenchymal lung nodule following their transplantation.Results:  Within the study period, 1754 SOTs were performed, of which 45 biopsies met study criteria. Overall, the incidence of PLB in SOT was 3%. PLB established a diagnosis in 24 of 45 cases. The yield of PLB was better for combined biopsy technique (fine‐needle aspiration biopsy [FNAB]) and core biopsy than for FNAB alone (odds ratio [OR]: 4.2, 95% confidence interval [CI]: 1.2, 15.6), and for lesions that were malignant (OR: 10.0, 95% CI: 1.8, 75.4) or caused by an invasive fungal infection (OR: 5.0, 95% CI: 1.1, 27.9). Complications occurred in 13% (6/45) of patients.Conclusion:  CT‐guided PLB is a safe modality that provides a moderate yield for diagnosing pulmonary nodules of malignant or fungal etiology in SOT recipients.
BCL‐2 Family of Proteins and Mammary Cellular Fate
Authors: Colitti M. 
Published: January 2012

SummaryThis review focuses on the pro‐apoptotic and anti‐apoptotic Bcl‐2 family members involved in apoptosis, which is the predominant process controlling cell remodelling during post‐lactational mammary gland involution. The members of the Bcl‐2 protein family, whose expression levels are under the control of lactogenic hormones, internally control this mechanism also during lactation. They can physically interact with each other, sometimes in an antagonistic manner. Mammary glands undergo repeated cycles of structural development, functional differentiation and regression, therefore provide a unique model for investigating this family of proteins that regulate the fate of the secretory cells and consequently milk yield. The involvement of Bcl‐2 family members is reviewed in mammary tissue during morphogenesis, at different stages of lactation cycle and in comparison with dairy and laboratory animals.
Total phenolic, size‐fractionated phenolics and fucoxanthin content of tropical Sargassaceae (Fucales, Phaeophyceae) from the South Pacific Ocean: Spatial and specific variability
Authors: Lann Klervi Le , Ferret Claire , VanMee Elise , Spagnol Charlène , Lhuillery Marie , Payri Claude , Stiger‐Pouvreau Valérie 
Published: January 2012

SUMMARYThis innovative study investigates 18 Turbinaria and Sargassum brown seaweed samples from three archipelagos of the South West Pacific Ocean. The phenolic content of crude and size‐fractionated extracts was determined by the Folin‐Ciocalteu method; fucoxanthin was measured using high performance liquid chromatography. Although the phenolic content proved to be low for the species of both genera tested, the levels in the species of Turbinaria were higher than those of Sargassum tested, except in the Fiji islands where both species produced similar contents. These investigations also highlighted variations of total phenolic content with spatial, reef morphology and depth. A large number of small phenolic compounds (<2000 Da) were observed irrespective of the genus analyzed. Nevertheless, the composition of the phenolic pool varied in relation with the genus, the archipelago from which the material was collected, geomorphological features and the depth of each collection field site. A similar observation was for fucoxanthin content and in general, the measured constituents of the Turbinaria were less than those of the Sargassum species. The results are discussed in terms of inter‐ and intra‐specific variability. Variations in both phenolic and fucoxanthin content were noted in tropical members of the Sargassaceae; such differences could be a result of specific chemical defense mechanisms adopted by members of each genus.
Unique distribution of epiphytic Neosiphonia harveyi (Rhodomelaceae, Rhodophyta) along sargassacean hosts
Authors: Yamamoto Keigo , Yoshikawa Shinya , Ohki Kaori , Kamiya Mitsunobu 
Published: January 2012

SUMMARYAlthough epiphytism is generally heaviest on older portions of the host thallus and both variation and abundance of epiphytes decrease with proximity to meristematic apices, Neosiphonia harveyi (Bailey) Kim, Choi, Guiry and Saunders was frequently found on upper parts of sargassacean hosts. This study compared density, thallus length and fertility of epiphytic N. harveyi among different regions of Sargassum patens C. Agardh thalli to reveal a unique distribution pattern of this epiphyte. The majority of epiphytic N. harveyi was observed on the upper part of host thalli and was seldom seen near the basal part. Over a 3‐month period, mean epiphyte density was greater on host apices while thallus length and fertility were greater on subapical portions of host thalli, suggesting the colonization by this epiphyte near the apical part of the host. Distribution patterns of this epiphyte were similar among S. patens growing at different depths. Apical portions of S. patens appear to be more suitable substrata for N. harveyi settlement and colonization compared with other portions of the host thallus, regardless of depth.
Timing of injury in utero causing respiratory inhibition after crying
Authors: Minowa Hideki , Bando Yuka , Yasuhara Hajime , Ebisu Reiko , Ohgitani Ayako 
Published: January 2012

AbstractBackground:  The aim of this study was to clarify the timing of injuries in utero that cause respiratory inhibition after crying (RIAC). We evaluated infants with cranial ultrasound abnormalities diagnosed during hospitalization.Methods:  We retrospectively examined the medical records of preterm infants who were treated in the neonatal intensive care unit at Nara Prefectural Hospital in Nara, Japan from January 2006 through December 2010. Inclusion criterion was gestational age less than 34 weeks. We evaluated the perinatal factors and cranial ultrasound abnormalities associated with RIAC, feeding hypoxemia, and prolonged apnea. We also evaluated the timing of appearance of cranial ultrasound abnormalities.Results:  A total of 125 infants were examined. Mean gestational age was 30.6 ± 2.4 weeks and mean birthweight was 1465 ± 454 g. The numbers of infants who showed RIAC, feeding hypoxemia, and prolonged apnea were 44, 48, and 63, respectively. Among 91 infants who showed cranial ultrasound abnormalities, 67 had increased echogenicity in the ganglionic eminence (GE). There was a significant correlation between increased echogenicity and RIAC (P < 0.001). Of the infants who showed increased echogenicity in the GE, 19 had this finding during the course of hospitalization. In these 19 infants, however, gestational age of those with RIAC was less than 31 weeks.Conclusion:  We speculate that the timing of intrauterine injury resulting in RIAC in infants is less than 31 gestational weeks.
Outcomes of inborn and transported extremely premature very‐low‐birthweight infants in Hawai‘i
Authors: Kuo Sheree , Kimata Chieko , Akamine Kristie , Young Brandon , Balaraman Venkataraman 
Published: January 2012

AbstractBackground:  Delivery of premature infants outside tertiary care centers is not always preventable. The aim of this study was to compare rates of survival and common morbidities in extremely premature babies transported to a level III facility versus those born at the level III center.Methods:  Retrospective chart review was performed on all neonates born at ≤ 28 weeks of gestation with birthweight ≤1500 g who were admitted to the Newborn Intensive Care Unit at Kapi‘olani Medical Center for Women and Children (KMCWC) between 1 January 2000 and 31 December 2005. Infants were divided into two groups, those born at KMCWC (Inborn) and those born at level I institutions and subsequently transported (Transport) to KMCWC.Results:  A total of 394 neonates met the study criteria; 349 were inborn while 45 were transported. Survival rates were identical for both groups. However, the Transport group survivors displayed a significantly longer mean length of stay and higher rate of severe retinopathy of prematurity than those in the Inborn group (P≤ 0.01).Conclusion:  Identical rates of survival in both groups suggest that community medical professionals are providing satisfactory care to stabilize critical neonates without reducing their chances of survival. However, increased length of stay and higher rate of retinopathy of prematurity in the Transport group suggest that differences in medical management during the first few hours of life may adversely affect outcomes.